British NCEPOD Reveals Causes of Accidents
In My Opinion: A Debate: Is Succinylcholine Safe for Children?
Editorial: Are We Becoming Too Afraid of Complication?
APSF Supports Analysis of AIMS Safety Reporting Data
Letters to the Editor:
From the Literature: Does Esophageal Detector Device Really Work?
ASA Safety Tape Portrays OR "Catastrophe"
by John N. Lunn, M.D., FRCA, FANZCA
Confidential enquiries are nowadays almost an established part of the hospital practice of medicine in the United Kingdom. The Confidential Enquiry into Maternal Deaths has provided information about the delivery of care in midwifery and obstetrics which has resulted in changes in all aspects of childbirth not only in the UK but also in the whole of the developed world over a period of about 40 years. A similar evolution is happening with the confidential enquiries about the delivery of anesthesia and surgery.
The Confidential Enquiry into Perioperative Deaths (CEPOD) started in the early 1980s as a development of a study of anaesthetic-related deaths by the Association of Anaesthetists of Great Britain and Ireland. Surgeons joined this enquiry, which was charity-funded. Its first report was immediately greeted by government's agreement to support financially a similar independent enquiry in England (including the Defense Medical Services). Wales, Northern Ireland, and The Channel Islands agreed soon afterwards. The National Confidential Enquiry into perioperative Deaths (NCEPOD) was thus started. The independent (private) sector became involved as well and the different groups contribute money proportionately. NCEPOD is independent of government and any individual specialty. It is a cooperative exercise, particularly between surgeons and anesthesiologists. The ultimate oversight of the enquiry is vested in a steering committee whose membership comprises representatives of all the relevant medical Royal Colleges and their faculties and of the two founding associations (of anaesthetists and surgeons).
Each year a different sample of all the patients who die in hospital within 30 days of a surgical operation is selected for detailed study. AU material is pooled and individual hospitals cannot be identified. Reports of each year's work are published: children (1989) and a random selection (1990). Fifteen specific operations were chosen for study in 1991-2, and in 1992-3, deaths in patients aged between 6 and 70 years were studied. The enquiries are about the quality of the delivery of anesthesia and surgery; they are not about causation or culpability. The occurrence of death is used merely to identify cases for study.
Material is collected for study as follows. A local reporter for the Enquiry sends an outline of the identifying features about every patient who dies in hospital within 30 days of a surgical operation to the NCEPOD office. Questionnaires are then sent to the consultant clinicians involved in the care of these patients. The completed questionnaires are returned to the enquiry office. They are then stripped of any features which might reveal their source and are scrutinised by groups of specialists. The data are entered onto a computer, tabulated and then these, together with the comments of the advisory groups on individual cases, form the basis of the reports. These advisory groups are composed of consultants in all specialties who are nominated by appropriate specialist organizations and the membership is changed each year.
NCEPOD and CEPOD have reviewed samples from a total of 42,000 deaths in hospital after surgery. The messages in the reports for clinicians, nurses and managers are somewhat repetitive. They have indicated subjects which are appropriate for local consideration and have potential for change. The statistics in this article refer to the most recent report (1993) about 15 specific operations, and are reported here as percentages of the appropriate totals.
All patients are admitted under the care of consultants. Trainee surgical staff do sometimes (about 10% of the sample) fail to inform their consultants about new admissions of patients or changes in the clinical state of existing patients. The same is true of trainee anaesthetists: 23% of the sample were anesthetized by quite junior trainees and 60% of these did not seek advice from senior colleagues. Both specialties must ensure that no in-patient is taken to the operating room for surgery without the knowledge of the appropriate consultant. The impact of this recommendation on departmental staffing might be considerable and there would probably have to be changes in the programs of work of individual clinicians.
There are still too many operations which take place out-of-hours. NCEPOD has, in all its reports, advocated the provision of an emergency operating room at all times during the day in order that this might be lessened. We estimate that one third of acute hospitals provide this facility. One immediate effect of an increase in consultant involvement in operations out-of-hours would be that the enthusiasm, for the organizational change required, would no longer be so half-hearted.
It is an outmoded policy to advise that operations may be undertaken in institutions which do not have proper arrangements for the care of patients after operation. Recovery rooms were available in 90% and high dependency units in 18% of the institutions sampled. Intensive therapy units were available in 73% of those sampled. These essential services should be staffed 24 hours a day: not every hospital may need to have an intensive therapy unit and the other two essential services could be used as temporary holding areas.
Pathologists have for some time complained that the number of postmortem examinations has declined to a level which suggests that this useful educational mechanism has been lost. Hospital postmortems were done in 10% of the cases in the sample, and coroners' autopsies were performed in 34%. Quality of clinical service will be enhanced when this form of self-assessment by, and of, clinicians is again part of the everyday life of a hospital.
Eight percent of sample wire anesthetized by locums. The need for temporary appointments is recognized, but the dependence of employers on individuals who are prepared to undertake short periods of work seems to be greater than is justified. It has become clear that too many of these doctors are appointed despite the absence of appropriate current experience and they have to take responsibility for problems with which they are not familiar. Anesthesiologists often work by themselves without medical assistance (57% of the sample); 9% of these solo anesthesiologists were also locums.
The task for purchasers is to select providers who will deliver appropriate standards of care for their populations. The choices cannot be robust unless the data on which they are based are sound: it is obvious that the clinical records need to be reliable. It is recognized that the system for contracts is weakest at this point and that considerable investment is required to improve matters in order for the new arrangements for management in the UK to work. Purchasers can seek reassurance that the providers of their choice can give them the data to validate statements of their ability to meet demands. It is apparent that staffs of Medical Records Departments are overstretched everywhere and need more, support.
The use of these devices has increased considerably since these reports began and 95% of the patients in the sample had, for instance, a pulse oximeter attached during the operation. However, 11 % of the patients in the sample had no instrumental monitors attached at, or just before, induction of anesthesia.
Twenty-five percent of the sample population had some critical clinical event during the operation. When these happened, death was more likely to occur during the first 24 hours postoperatively.
It must be recalled that most of these patients were elderly (65% over 70 years) and most had other diseases from which many were already dying. There are many outstanding clinical events revealed in these enquiries. How can the toll from ischaemic heart disease or pulmonary thromboembolism, after deep vein thrombosis, be reduced? How should effective pain relief and even palation in lethal conditions be provided? The question also needs to be asked about the current place of diagnostic laparotomy in an era of modern imaging techniques, fine bore needle biopsy, and rapid cytology. Surgeons need to consider the needs of the whole patient particularly when cardiac failure, renal failure or diabetes are also present. Too many elderly patients die in pulmonary edema 24 hours after gross fluid overload (e.g. 12 liters intravenously during and immediately after surgery with no output). These patients often have widespread metastatic disease and their management might be better shared with internists. Similarly, in these patients, heroic attempts at ablative surgery for carcinoma of the oesophagus, stomach, pancreas or lung must be limited. Amputation of lower limbs is unnecessary when the patient is already dying from gangrene and more humane management with analgesic drugs is surely to be preferred.
It has become quite clear that there is need for definitive guidelines about the management of some conditions, particularly in the elderly. Trainees welcome these since they give them something to refer to whilst awaiting the presence of a more senior colleague. Care of a patient can follow a prescribed, and locally agreed upon, pattern and thus be continuous without the risk of interruption at weekends or holidays. Written guidelines about practice also allow for subsequent comparison in any exercise of quality assurance. Guidelines can also serve to remind managers of the need to ensure that proper services, including support staff, are available before developments are agreed. Such arrangements might include the availability of consultative opportunities, across a geographical boundary if necessary, when individuals have to practice without the immediate access to other experts; the obvious example of this is the provision of specialist medical consultants in single surgical specialty hospitals which are still too often also isolated geographically. Surgeons and anesthesiologists might also be encouraged not to agree to undertake certain operations in locations in which recommended essential services were not available.
Quality is that characteristic of an activity which may be improved. Some of the so-called quality initiatives in the health services do not yet seem to have borne fruit. No doubt they will, but meanwhile our Confidential Enquiries have revealed matters which are ready for change.
Dr. Lunn is Reader in Anaesthetics, University of Wales College of Medicine, Cardiff, CF4 4XN and Clinical Coordinator of NCEPOD. Copies of NCEPOD reports can be obtained for the appropriate fee from NCEPOD, 35-43 Lincoln's Inn Fields, London, WC2A 3PN.
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"No, succinylcholine should not be used routinely for elective pediatric surgery."
by Susan K. Woelfel, M.D.
No, succinylcholine should be used only when the clinician deems it necessary to have a relaxant with a rapid onset and short duration since the many side effects range from troublesome to life threatening.
The well-documented, undesirable side effects of succinylcholine include muscle pain, cardiovascular changes, arrhythmias and cardiac arrest, increases in intraocular and intragastric pressure, masseter spasm, myoglobinemia, myoglobinuria, association with malignant hyperthermia (MH), and hyperkalernia in susceptible patients. The risk of hyperkalemia has been highlighted recently with case reports of patients with unsuspected muscle disorders, primarily Duchenne's muscular dystrophy. It is for this reason that the FDA Anesthetic and Life Support Drugs Advisory Committee and the Pilot Drug review team, along with the four manufacturers of succinylcholine, have recently stated that succinylcholine is contraindicated for routine use in children and adolescents except for emergency tracheal intubation or in instances where immediate securing of the airway is necessary.
Many Side Effects
In children, the incidence of relatively minor and easily treatable side effects, such as bradycardia, muscle pain, and increase in intraocular or intragastric pressure is high. We modify our practice habits because of the common occurrence of many of these side effects. For example, we routinely administer atropine when we use succinylcholine. Also, patients may be pretreated with a non-depolarizing neuromuscular blocking drug in the hope of preventing muscle fasciculations and muscle pain. The increase in intraocular pressure may be attenuated with intravenous or inhalational anesthetic agents prior to administration of succinylcholine. If we are concerned about the increase in intragastric pressure and the risk of regurgitation and aspiration, then we apply cricoid pressure until the trachea is intubated. We adapt our method of anesthesia practice to avoid the side effects of the drugs we choose to administer.
Another group of side effects of succinylcholine has a lower incidence, may be dose-related, and is of debatable importance. Masseter spasm on induction of anesthesia may be a normal response to succinylcholine, (1) or the first indication of MH. Some advocate canceling the procedure, while others recommend continuing the procedure with halothane. (2) Is the child with masseter spasm more likely to have myoglobinuria postoperatively, and should we look for myoglobinuria in all children who receive succinylcholine? Myoglobinuria may also be a normal reaction to succinylcholine. (3-5) Patients with masseter spasm or myoglobinuria are difficult to counsel postoperatively because our information is incomplete. An example from our institution is a child who experienced myoglobinuria in the recovery room after receiving succinylcholine during a tonsillectomy, and then returned for treatment of a bleeding tonsil within six hours of his first operation. Is succinylcholine the drug of choice for this emergency procedure, with the possible increased risk of triggering MH? This child returned for two direct laryngostomies to evaluate hoarseness and eventually underwent removal of a laryngeal granuloma. Is halothane still the drug of choice for these short ENT procedures? The family required extensive counseling regarding the safety of anesthetic agents in their child, and not all the answers were clear. If succinylcholine was not used routinely, perhaps many such problems would be avoided.
The most dramatic complications of succinylcholine are hyperkalemic cardiac arrest and MH. These complications, although admittedly rare, are potentially line-threatening. Hyperkalemic cardiac arrest is most likely to occur in patients with certain disease states: neurological disease (paraplegia or stroke), massive trauma, muscular dystrophies, myotonia, burns, or MH. Twenty cases of hyperkalemic arrest, 11 of which were fatal, were reported from 1990 through 1993.1 Family history and creatine kinase levels identify only some patients with muscular dystrophy or other occult myopathies before elective surgery. In addition, patients susceptible to MH cannot be determined by the history and laboratory examinations preoperatively. These patients are at risk for life-threatening consequences when succinylcholine is chosen instead of a non-depolarizing drug.
Safe Drugs Available
Because of the significant side effects associated with succinylcholine administration, anesthesiologists have been searching for a non-depolarizing muscle relaxant with rapid, reliable onset of complete, neuromuscular blockades, short duration of action, and minimal cardiovascular side effects. Today, we have many such drugs to produce rapid relaxation. They include mivacurium, rocuronium, and perhaps atracurium and vecuronium as well. Priming techniques or administration of more than 3 to 4 times the intubation dose of relaxant will also produce rapid onset paralysis. In addition, in recent years there there has been more discussion of monitoring techniques available to judge the depth of neuromuscular blockade in pediatric patients, as well as the appropriate time to administer reversal agents. Therefore, the hesitancy to use non-depolarizing drugs in pediatric patients because of fear of persistent paralysis should be less prevalent.
In summary, the elective use of succinylcholine in pediatric anesthesia should be abandoned. The unwanted side effects of succinylcholine are well known. More important, viable alternatives to succinylcholine now exist for intermediate or long surgical procedures. With short-acting non-depolarizing relaxants available, succinylcholine is obsolete for routine anesthesia care.
Dr. Woelfel is Associate Professor of Anesthesiology, University of Pittsburgh School of Medicine, and staff anesthesiologist at Children's Hospital of Pittsburgh, Pittsburgh, PA.
1. Van Der Spek AFL, Fang WB, Ashton-Miller JA, et al: Increased masticatory muscle stiffness during limb muscle flaccidity associated with succinylcholine administration. Anesthesiology 69:11,1988.
2. Littleford JA, Patel LR, Bose D, et al: Masseter muscle spasm in children: Implications of continuing the triggering anesthetic. Anesth Analg 72:151-160,1991.
3. Ryan JF, Kagen LJ, Hyman Al: Myoglobinemia after a single dose of succinylcholine. N Engl J Med 285:824825,1971.
4. Harrington JF, Ford DJ, Striker TW: Myoglobinemia and myoglobinuria after succinylcholine in children. (Abstract) Anesthesiology 59,A439,1983.
5. Plotz J: Succinylcholine in children (Letters to the Editor). Anesth Analg 67:798-W2,1988.
6. Kent RS: Revised label regarding use of succinylcholine in children and adolescents: I (Correspondence). Anesthesiology 80:244-245, 1994.
"Yes, succinylcholine can be used routinely with safety in children."
by Robert C. Morell, M.D., and Jeffrey M. Berman, M.D.
Succinylcholine has been used in pediatric anesthesia for more than 40 years. Currently, no other neuromuscular blocking agent has the same pharmacokinetic profile relative to speed of onset and duration of action. Furthermore, there is no substitute for succinylcholine when intramuscular administration is required. Controversy regarding the 'routine' use of succinylcholine in children was recently fueled by a labeling change initiated by one manufacturer of the drug and the FDA. As of November 1993, succinylcholine became contraindicated in children and adolescent patients "except when used for emergency tracheal intubation or in instances where immediate securing of the airway is necessary." (1) The rationale for this labeling change was based on a total of 36 cases of unexpected cardiac arrest which were reported to occur after the administration of succinylcholine to .apparently' healthy children and adolescents who were subsequently found to have myopathies. (2)
This contraindication by decree is unacceptable to many anesthesiologists, including recognized experts in pediatric anesthesia. Recent published letters by Badgwell et al (3) Lennan et al (4) and Morell et al. (5) voice strong opposition to the label change and advocate the continued use of succinylcholine in pediatric patients. These cardiac arrests, while temporally associated with the administration of succinylcholine, may have multiple etiologies. Although many of the reports document hyperkalemia, several cases report either normokalemia or fail to report serum potassium. Bradycardia during halothane induction is not uncommon in children. Due to their high vagal tone, hypoxia or stimulation of certain reflexes may also result in asystole.
The FDA's decision to issue a contraindication rather than a warning was based on the inability to predict which patients may be at risk for sudden cardiac arrest following the administration of succinylcholine, and the lack of effective management should that event occur. (2,6) Although predictability of adverse drug reactions is desirable, we must always be ready for the unexpected. Prompt and proper treatment is paramount. In many of the cited cases of hyperkalemic cardiac arrest, including one fatality, calcium was not administered despite measured serum potassium levels in excess of 10 mEq/L. (7-9) In hyperkalemia, the resting membrane potential moves closer to the threshold for depolarization. Calcium is crucial in treating hyperkalemia because calcium raises this threshold, directly antagonizing the electrophysiologic effect of potassium. The appropriate administration of glucose and insulin or sodium bicarbonate, which moves potassium intracellularly, is not as effective nor as rapid.
Data Support Sux
In short, we believe that the arguments attempting to justify the contraindication of succinylcholine in children and adolescents are flawed and not supported by the available data. In response, we put forth the following arguments:
1. Succinylcholine following halothane does not carry the same risk as succinylcholine following thiopental. Out of 23 reported cases of sudden cardiac arrest after succinylcholine, 20 documented the administration of halothane prior to the administration of succinylcholine. There were 2 cases in which isoflurane and I case in which cyclopropane were administered prior to succinylcholine. None of these cases involved an intravenous induction with sodium pentothal."' It has been demonstrated by several investigators that the choice of induction agent can significantly affect serum potassium levels after succinylcholine, and that benzodiazepines and sodium pentothal may attenuate the usual rise in potassium.' The clinical experience of Lerman and others supports these observations.'
2. Adolescents are not the same patients as infants and young children. Although it may be difficult to make the diagnosis of Duchenne muscular dystrophy in an infant or young child, most anesthesiologists would have little trouble recognizing this myopathy in a 14 or 15-year-old. It is interesting to note that among Dr. Schulte-Sasse's nine reported cases of sudden cardiac arrest in apparently 'healthy' children, two carried a preoperative diagnosis of a myopathy, yet succinylcholine was still administered. The ability to predict patients at risk was not an issue in at least these two cases.
3. Succinylcholine is useful and unique in many situations where emergent or immediate securing of the airway is not mandatory. The scenario of the suspected difficult intubation may arise in which, despite the adequacy of mask ventilation after induction, the anesthesiologist does not wish to 'burn any bridges' by using a non-depolarizing muscle relaxant with a slower onset and longer duration. The utility of succinylcholine administered as an infusion for suspension microlaryngoscopy is without equal, particularly when the surgery requires that the vocal cords be absolutely immobile for indeterminate periods of time.
In summary we believe that succinylcholine is as safe and efficacious today as it was last year and the year before. Halothane is a potent trigger for malignant hyperthermia. However, we have yet to contraindicate halothane in the pediatric population because we have recognized the adverse reactions and have developed effective means of treating a potentially lethal complication. Hyperkalemia after succinylcholine is no different. It is no different than anaphylaxis after prolamine or low molecular weight dextran or penicillin. Anaphylaxis, in fact, accounts for more than 500 deaths in the United States annually, with an incidence which may be as high as I in every 3,000 inpatients.' We must always expect the unexpected and treat each of our patients accordingly, with our best training, experience and judgment. The choice of muscle relaxant in a pediatric patient should be weighed against the risks and benefits in the individual case. Succinylcholine should not be chosen at random, nor should any drug. Until a muscle relaxant with as favorable a pharmacokinetic and pharmacodynamics profile is developed and released, the use of succinylcholine should be directed by the anesthesiologist, not by corporate or governmental officials. The unique properties of succinylcholine expand its utility far beyond the emergent scenario.
Dr. Morell is Assistant Professor W Dr. Berman is an Instructor, Department of Anesthesia, The Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC.
1. Package Insert: Anectine (Succinylcholine Chloride) Injection, USP. Burroughs Wellcome Company, June 1993.
2. Kent RS: Revised label regarding use of succinylcholine in children and adolescents: I and 11 [Reply]. Anesthesiology 1994;80:244-245.
3. Badgwell JM, Hall SC, Lockhart C: Revised label regarding use of succinylcholine in children and adolescents: 11 [Letter]. Anesthesiology 1994;80:243.
4. Lerman J, Berdock SE, Bissonnette B, et al: Succinylcholine warning. Can j Anaesth 1994;41:165.
5. Morell RC, Berman JM, Royster RL, Petrozza PH, Kelly JS, Colonna DM: Revised label regarding use of succinylcholine in children and adolescents: I [Letter]. Anesthesiology 1994;80:242.
6. Katz L, Wright C, Harter J, Zung M, Scally D, Spyker D: Revised label regarding use of succinylcholine in children and adolescents: I and 11 [Reply]. Anesthesiology 1994;80:243-244.
7. Stelzner J, Kretz FJ, Rieger A, Reinhart K: Anesthefikainduzieiter herzsillstand. Anaesthesist 1993;42:4446.
8. Schulte-Sasse VU, Eberlein HJ, Schmucker 1, Underwood D, Wolbert R: sollte die verwendung von succinylcholin in der kinderanasthesie neu uberdacht werden? Anaesthesiol Reanimat 1993;18:13-19.
9. Mehler J, Bachour H, Simons F, Wolpers K: Herzstillstand wahrend der narkoseeinleitung mit hatothan und suceinylcholin bei einem saugling. Anaesthesist 1991;40:497-501.
10. Seay AR, Ziter FA, Thompson JA: Cardiac arrest induction of anesthesia in Duchenne muscular dystrophy. J Pediatr 1978,93:88-90.
11. Genever EE: Suxamethonium-induced cardiac arrest in unsuspected pseudohypertrophic muscular dystrophy. Br J Anaesth 1971;43:984-986.
12. Solares G, Herranz JL, Sanz MD: Suxamethonium induced cardiac arrest as an initial manifestation of Duchenne muscular dystrophy. Br J Anaesth 19860:576.
13. Delphin E, Jackson D, Rothstein P: Use of succinylcholine during elective pediatric anesthesia should be reevaluated. Anesth Analg 1987;66:1190-1192.
14. Linter SPK, Thomas PR, Withington PS, Hall MG: Suxamethonium associated hypertonicity and cardiac arrest in unsuspected pseudohypertrophic muscular dystrophy. Br J Anaesth 1982;54:1331-1332.
15. Wilhoit RD, Brown RE Jr, Bauman LA: Possible malignant hyperthermia in a 7-week-old infant. Anesth Analg 1989;68:68M91.
16. Wang JM, Stanley TH: Duchenne muscular dystrophy and malignant hyperthermia two case reports. Can Anaesth Soc j 1986;33:492-497.
17. Arnould JF, Bigot A, Steenbeke L, David A, Mussini JM: Arret circulatoire lors d'une anesthesie generale chez un enfant porteur d'une myopathie de Duchenne meconnue. Ann Fr Anesth Reanim 1986;5:612614.
18. Oudesluys-Murphy AM, van Berkel M, van den Brand HM: Unexplained sudden death under general anaesthesia. Lancet 1985;1:696-697.
19. Hendemn WAV: Succinylcholine-induced cardiac west in unsuspected Duchenne muscular dystrophy. Can Anaesth Soc j 1984;31:444 44 .
20. Vatashsky E, Aronson HB: Intravenous flunitrazepam in the prevention of the side effects of succinylcholine. Isr j Med Sci 1982;18:587-589.
21. Roelofse JA, Hartshorne JE: Serum potassium after enflurane-succinylcholine induction of anesthesia in children receiving rectal midazolam
as premedication. Anesth Prog 1992;39:69-72.
22. Keneally JP, Bush GH: Changes in serum potassium after suxamethonium in children. Anaesth Intens Care 1974,2:147-150.
23. Magbagbeola JAO, Adadevoh BY, Durowoju JEO: Influence of ether anaesthesia on suxamethonium-induced hyperkalaemia. Anaesthesia 1974;29:429-434.
24. Konchigeri HN, Tay C-H: Influence of pancuronium on potassium efflux produced by succinylcholine. Anesth Analg 1976;55:474-477.
25. Bochner BS, Lightenstein LM: Anaphylaxis [Review].
N Engl j Med 1991;324:17&5-1790. February 16, 1994
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New debate about the safety of anesthetic medications that have been used literally millions and millions of times over several decades seems as if it would be, by definition, healthy and valuable. However, the tone and result seem to be different now in the mid -1990's. Analogous changes in the medical device field seem also to be taking place. Issues (often involving a very small number of cases of questions or supposed adverse effects) that in previous times would have been discussed in the literature and evaluated by anesthesiology scholars now appear to virtually instantly provoke broad, sweeping indictments and immediate actual or threatened regulatory intervention to limit or forbid the use of the medication or device.
It is worthwhile to examine the admittedly difficult balance between years or decades of effective, apparently safe use of something and the understandable desire to make things now as safe as humanly possible for our patients.
Is Sux Safe? Myopathy Very Rare
As reflected in the debate that is the lead article of this issue of the Newsletter, succinylcholine has been administered to children and adolescents many millions of times. As with all medications, there are both predictable and unpredictable rare (actually extremely rare) adverse responses. Proponents of the very strong FDA-approved labeling change (which, as correctly noted by letter writers to Anesthesiology, has significant medical legal implications for plaintiffs' lawyers) making succinylcholine 'contraindicated' for children and adolescents cite as their main point that it is impossible to know which child or teen has an undiagnosed myopathy that may predispose to dangerous hyperkalemia after succinylcholine. Therefore, they argue, no child or teen should receive succinylcholine unless there is one of the small number of specific positive indications.
Opponents of this functional ban on succinylcholine correctly state that this change breaks new ground for establishing contraindications and, if this is the way it is going to be, there are a host of other medications that should be limited or banned, including sodium thiopental for fear of undiagnosed porphyria and intravenous antibiotics for fear of anaphylaxis. While extreme to make a point, these proposals highlight the issue are we getting too afraid? Proponents of the ban say there are fully equivalent alternative medications. Opponents of the contraindication state forcefully that this simply is not true and also seem possibly to question the motives of the manufacturers involved.
Spinal Lidocaine Too?
There is another, apparently similar, controversy brewing. In what appears to be a reasoned, thoughtful analysis, the safety of hyperbaric lidocaine in dextrose
for routine spinal anesthesia was questioned in an editorial in January's Anesthesia and Analgesia.' This medication also has been used effectively and safely many millions of times. Now a report of four cases of transient radiculopathy out of 88 patients prompts a review of what is known and results in the suggestion that lidocaine may, in fact, be neurotoxic in this setting. Microcatheters for continuous spinal infusion have already been banned, in retrospect possibly because they delivered this toxic drug to a small area of effect. Because of the obvious climate of rapid trial, conviction, and execution in this arena, can any modern anesthesiologist doubt that there is active consideration right now of a new contraindication and an effective ban of hyperbaric lidocaine for routine spinal anesthetics? Is this reasonable or are we becoming too afraid? How can we tell? What is happening here?
One important thing that is happening here is tied directly to the evolution of the anesthesia patient safety movement over the last decade or so. Because anesthesia is so much safer and the major accidents causing cardiac arrest, brain damage, and death have been so significantly decreased, new emphasis and attention have been focused on issues that previously may have been overshadowed by the then-unquestioned large issues in anesthesia safety. Possibly, problems that before were simply not recognized may now stand out more in the spectrum of anesthesia complications and, as a result, receive attention for the first time. A second possibility is that new sophistication and methods of investigation exist which allow detection of previously unrecognizable problems. A third consideration is that the described phenomena are actually new problems that could not have been seen before as they did not exist. At first pass, this seems unlikely. Finally, perhaps these really are not problems at all and over enthusiasm at the potential of finding problems helps create an impression of trouble where no problem exists.
The interaction of fears on the part of some (possibly only a few?) anesthesiologists with the governmental and regulatory environment is critical in this discussion. In the succinylcholine debate, the U.S. Food and Drug Administration (FDA) played a significant role in the decision to create the contraindication. Has there been a shift on the part of government in general and the FDA in particular from the traditional mission of 'facilitate and educate' to a new emphasis on the concepts of 'regulate and punish"? This particularly is where the connection to medical devices is made. Mr. James S. Benson, Senior Vice President of the Health Industries Manufacturers Association, spoke in February to a medical design and manufacturing meeting and specifically commented that it appears that the FDA is promoting a strong "get tough' image. He noted that the public confidence in both the medical manufacturing community and the FDA are very low due to things such as the highly publicized questioned safety of some types of artificial heart valves, silicone breast implants, various generic drugs, and many other things. There is concomitant parallel pressure coming from the U.S. Congress. In response, the FDA seems to be significantly tightening control, regulation, and enforcement. Very importantly in this discussion, it is very likely that this atmosphere promoting 'get tough' regulation by government makes it much more probable that the response to any perceived safety issue will take the form of regulation and limitation. In even the recent past, regulators likely would have allowed more time for the issue to develop on both sides in the scientific literature and discussions (such as panels and symposia at national meetings). In the new 'tighter' climate, it seems this is not going to be possible and new regulations come down comparatively very quickly.
Are we (and the regulators who now have such a great role in our professional lives) becoming too afraid? There is no easy simple answer. Striving toward the goal of absolute minimum risk is, of course, good. However, it is possible to throw out the baby with the bath water and quickly condemn or even eliminate medications, devices, or strategies that have been time-tested and considered safe for a very long time. Therefore, as is usually the case, the current path should be somewhere between the two extremes. Yes, there should be some fear and some regulation. No, these should not be unreasonable, onerous, and unnecessarily restrictive. It seems as if there needs to be careful thought and evaluation leading to the implementation of common sense actions. There should be the intense, thorough involvement of the practitioners directly affected by the issues. Unilateral action rarely is appropriate. National groups and societies can organize open invitation meetings focused on specific issues and the proceedings can be published as journal supplements for all practitioners to evaluate. Then their input into the consensus process can be based on the most recent, complete data and analysis.
Before the label change contraindicating succinylcholine in children and adolescents, there should have been the equivalent of a 'consensus conference' involving practitioners, representatives of involved professional societies, researchers, manufacturers, and regulators. However difficult and however long it took, this group should have kept at it until there was some type of agreement as to the most reasonable course. Yes, this is expensive and difficult to organize. However, the stakes are high and this type of activity is precisely what we as a profession should be intensely involved with. Device questions can be handled the same way. There should be an immediate reevaluation through this type of mechanism of the succinylcholine decision. Hyperbaric lidocaine spinals should also be approached in this manner. So, too, should future questions of a similar nature. Only then will we be able to practice without unnecessarily heavy-handed regulation and also without wondering if we are becoming too afraid.
John H. Eichhorn, M.D. Editor, APSF Newsletter
1. deJong RH. Last round for a 'heavyweight'? Anesth Analg
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by Jeffrey B. Cooper, Ph.D.
Professor John Senders has been commissioned by the APSF to analyze data from the Australian Incident Monitoring Study. The AIMS is a collection of 2,000 anesthesia-related critical events reported from throughout Australia. A set of 21 articles in a recent symposium issue of Anesthesia and Critical Care described various aspects of the database.(1) It has been learned, for instance, that hypoxic events discovered by oximetry most often arise from endobronchial intubation (2) and that capnography ranked second after oximetry as the monitor most likely to detect an event during general anesthesia.(3) From 19 cases of air embolism, a set of maneuvers was identified as being most effective for treating air embolism. (4) In 58% of 85 cardiac arrests, a clear anesthetic-related cause was identified. (5) The study examined numerous other issues, e.g., applications and limitations of blood pressure monitoring, patient awareness, problems occurring before induction. This extensive AIMS report is a gold mine of information about anesthesia safety. A summary of the AIMS study recently appeared in the Newsletter of the Society for Technology in Anesthesia and will be reprinted in an upcoming issue of the APSF Newsletter.
Goal is Reporting Form
Dr. Senders will be reviewing the AIMS data with the objective of creating an instrument for potential use in an Anesthesia Safety Reporting System in the US, modeled after the system for reporting aviation near misses (ASRS Aviation Safety Reporting System). It is expected that much can be learned from the AIMS data and techniques. A major emphasis of a US Anesthesia Safety Reporting System would include feedback to the clinical community, probably via the APSF Newsletter. The basis for that has already been established in the feature "In My Experience." Dr. Senders has published extensively on human error and human performance. His book, Human Error: Causes, Prediction and Reduction' is particularly useful in the anesthesia domain. His eclectic interests and experience in studying and developing concepts of human performance should provide fresh insights to similar problems in anesthesia.
Dr. Cooper, Mass. General Hospital, Boston, is on the APSF Executive Committee.
1. Webb RK, Currie M, Morgan CA, Williamson JA, Mackay P, Russell WJ and Runciman WB: The Australian incident monitoring study: An analysis of 2,000 reports. Anaesth Intens Care 21:520-529,1993
2. Runciman WB, Webb RK, Barker L and Currie M: The pulse oximeter: Applications and limitations: An analysis of 2,000 incident reports. Anaesth Intens Care 21:543-550,1993
3. Webb RK, Van der Walt JH, Runciman WB, et al: Which monitor? An analysis of 2,000 incident reports. Anaesth Intens Care 21:529-542,1993
3. Williamson JA, Webb RK and Russell WJ, Runciman WB,: Air embolism: An analysis of 2,000 incident reports. Anaesth Intens Care 21:638-641,1993
4. Morgan C, Webb RK, Cockings J and Williamson JA: Cardiac arrest: An analysis of 2,000 incident reports. Anaesth Intens Care 21:626-637,1993
5. Senders JW and Moray NP: Human Error: Causes, Prediction
and Reduction, Lawrence Erlbaum Associates, London, 1991
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Asepsis in Anesthesia Often Under-Appreciated
To the Editor
Several years ago anesthesia residents used the old red rubber endotracheal tubes. After use, we used a bottle brush to scrub them in the sink. I was not taught to avoid handling the lower part of the tube, and I was cavalier about where I laid the uncovered tube. Being new to medicine and naive, I thought of the operating room as a clean, sterile, environment. Now we are taught to avoid contamination of the unpackaged endotracheal tube, keeping it sterile until it resides in the patient's own local flora. I was originally taught to intubate using a method of opening the mouth wide with my right long finger and thumb on the patient's molars. Many residents are now being taught to intubate without putting their fingers in the patient's mouth at all. By carefully inserting the blade in the patient's mouth and lifting gently, advancing in increments, the intubation can be accomplished in most patients with only the blade and tube entering the mouth. Most of us wear gloves when intubating, to protect ourselves as well as the patient. Things change.
Why all the fuss? Why be concerned with putting a laryngoscope blade that has been soaked in Cidex, gassed or autoclaved, into a patient's mouth? The problem lies in what happens to the blade from the time it is disinfected to its insertion in the patient's mouth. It is rare that it is protected from the contaminated environment. The disinfected blades are frequently delivered to a potentially contaminated surface. In preparing for our case, we have often contacted contaminated surfaces prior to assembling the blade and its handle. But we use silverware that is often in contact with a table in a public restaurant, don't we? Next time you are in a restaurant, watching an employee clean an adjacent table, wiping the table top, then wiping the seats, then going to the next table top, think about it. Well, the incidence of cross contamination must be very small, since I only get diarrhea once every few years. If I had the opportunity, I would use squeaky-clean silverware.
Microorganisms are real. What if you were eating in the operating room? Big time organisms there. Hepatitis virus remains virulent in dry secretions for two or three days. Nosocomial pneumonia organisms, antibiotic resistant hospital strains, the same strains that are the killers in the ICU, have been cultured off of the knobs of the flowmeters of the anesthetic machine. Herpes viruses may be present. Tuberculosis is back and some strains are highly resistant. AIDS virus, a pansy of a virus outside the body, and probably not a threat, but it has given us more and more patients who are immunodepressed. There are also patients who are immunodepressed because of chemotherapy, graft-host rejection prophylaxis, and other reasons. Those patients should be protected from possible contamination resulting from our care.
When you place your hands in a patient's mouth to intubate, to extubate, in airway insertion and removal, in placing and removing esophageal stethoscopes, nasogastric tubes, in auctioning the pharynx, it is difficult, if not impossible, not to spread secretions. The anesthesia circuit has to be handled, the flowmeter knobs, I.V. poles, etc. have to be adjusted, or positioned. As the anesthetic progresses, there is the possibility for further spread of the organisms. Many (most?) of us wear gloves. Our anesthesia working space is contaminated. The gloves are a barrier between ourselves and the contaminants, but rarely do they protect the patient.
However, I still see anesthetists not wearing gloves to intubate, laying unpackaged endotracheal tubes on the patients chest prior to intubation, and wedging a tonsilar sucker between the pad and the table between repeated pharyngeal suctions (how often is that space well cleaned!)
In spite of the potential, there is apparently a low incidence of cross contamination. Most likely we would not be aware of causing a nosocomial infection. We probably would not learn of some infections because the symptoms may not appear for months. Other infections may be attributed to other parts of the hospital. If the apparent incidence is low, which it probably is, there should still be concern, for the numbers are large. There are approximately 18,000,000 endotracheal anesthetics given yearly in this country alone. The American Society of Anesthesiologists, the Joint Commission of American Hospitals, and others, recommend that all instruments that come in contact with mucous membranes undergo a 'high level of disinfection." For the last few years, I have been working as a locum tenens anesthesiologist in eight different states. I know first hand that there are many anesthetists who still hand wash their blades at the sink. Many more comply with the standard recommendations. In either case, unless the blades are kept clean or sterile right up to the insertion into the patient's mouth, the possibility of introducing pathogens into the patient is a real risk. With so little effort, with such a small change in technique and habits, this risk can be avoided. Disinfected blades can be packaged in a manner that allow their placement on the handle while still in the package with a .no touch' technique, the cover removed only immediately prior to insertion in the mouth, and then the blade immediately placed back into the same package for pick up and cleaning.
Alternatively, a sterile barrier film sheath, recently made available, can be applied in a same "no touch" technique, the outer cover removed immediately prior to insertion into the patient's mouth, and immediately after intubation, the contaminated sleeve can be disposed of, allowing the connected blade-handle to be placed on any work surface, ready for another sleeve application. This latter device is kinder to bulbs and blades, and they have a longer life before repairs or replacement are necessary. With a little practice, an esophageal stethoscope can be fed into the mouth or nose in a .no touch" technique straight from its package. With a little practice, other similar 'no touch' techniques can be used for temperature probes, nasogastric tubes, etc.
Things change. Cloves are becoming a way of life in anesthesia practice. We are more conscious of the implications of needle sticks. We have become more aware of possibilities of our techniques contributing to a patient's becoming infected. We are increasingly under the scrutiny of others in the O.R. who have been more involved in aseptic practices. For the most part, treatment of our laryngoscope blades has been mandated by outside influences. Their intentions, however, have fallen short. The important factor is to keep the blade aseptic right up to its insertion. It is difficult or perhaps impossible to prevent contamination of our work area, but by awareness, and new techniques, we can avoid contaminating endotracheal tubes, laryngoscope blades, esophageal stethoscopes, etc. The change required to do this is minuscule, and takes no further time. It is good and right so to do.
William M. Slater, M.D. Las Cruces, NM
No-Needle IV System Praised
To the Editor
Recently our department switched to a needleless system of blunt tipped needle-like devices for use in the operating rooms. Unfortunately, sharp steel needles are still commonly used in the operating rooms, largely for aspiration from various containers. All of the systems which we considered required the additional expense and inconvenience of at least one type of device for this purpose. This in turn led to additional storage problems on the anesthesia cart. I am sure this hassle and expense is shared by many anesthesiology departments throughout the country. Worse still is the continued risk assumed by those departments that do not utilize such systems. Widespread acceptance of needleless systems could become a reality only if there are no significant obstacles to their use. An immediate concern is the absence of pre-pierced rubber stoppers on medication and fluid containers. If vial makers switched to this more practical alteration of an old stand-by, this reduction in use of sharps could be more readily accomplished.
The Anesthesia Patient Safety Foundation is an ideal forum to address this concern. I suggest that the APSF sponsor a forum for health care providers, manufacturers of needleless systems, and vial and medication manufacturers to work toward a consensus of the problem. The goal would be the practical elimination of the use of sharps for anything other than patient contact. If anesthesia machines can be "standardized' and 'modernized' why not our IV tubing and injection/aspiration devices? Although this is largely an issue of health care provider safety, patient safety is an important consideration, and needs to be addressed here as well.
George Gabrielson, M.D. Assistant Professor of Anesthesiology
Director, Liver Transplantation Section The Mount Sinai Medical Center
New York, NY
Pulmonary Edema-Possible Prevention, Cause
To the Editor
This is in response to the Letters to the Editor on the subject of postoperative pulmonary edema. In our institution, we have observed and recorded episodes of pulmonary edema in young, strong, healthy patients after suffering airway obstruction following extubation since we started our quality improvement program several years ago. We have assumed for quite some time that the diagnosis was negative pressure pulmonary edema.
We agree with Dr. O'Hara when she states, 'This happens more in July, when new residents learn how to evaluate awakening and readiness for extubation, but these incidents happen to experienced anesthesiologists as well.' For several years in our teaching institution, the incidence was around one in 2,000 extubations. In 1988 we contacted an endotracheal tube manufacturer to build a modified endotracheal tube specifically designed to have the capability to deliver topical anesthesia to the upper airway to eliminate or diminish bucking and coughing during emergence from general anesthesia. In subsequent studies which we undertook, we were able to determine that this was the case.'
For the last two years we have been using topical lidocaine prior to emergence and allowed the patients to wake up with the endotracheal tube in place. By doing so we were able to eliminate or greatly minimize bucking, coughing and also (as a by-product) laryngospasm and/or any other form of upper airway obstruction that may result in pulmonary edema. Negative pressure pulmonary edema following laryngospasm was decreased to one in 10,000.
Another by-product has been the decrease and/or elimination of post intubation sore throat, since most of the trauma to the airway is due to bucking and coughing during emergence, especially if the intubation has been smooth and easy.
Marc G. Viguera, M.D.
Head, Department of Anesthesiology The Buffalo General
Hospital Buffalo, NY.
ENDOTRACHEAL TUBE constructed to administer local anesthetic solution to the trachea as patient is emerging from general anesthesia. Top: Syringe 0 local anesthetic attached to injection port, entirely separate from cuff pilot tube. Bottom: Injection of local anesthetic through multiple side holes intended to disperse solution and bathe tracheal mucosa prior to emergence to prevent or reduce coughing and bucking thought to lead to, in some cases, postoperative negative pressure pulmonary edema.
1. Shelsky R, Diakun T, Viguera, M. The efficacy of topical lidocaine administered via the Mallinckrodt Niagara endotracheal tube in attenuating bucking and coughing upon emergence from general anesthesia. Rev. Esp. Anesthesiol. Reanim. 1992; 39:316-318
Contaminated N20 is Possible Toxic Etiology
To the Editor
In a recent Newsletter, six cases with pulmonary edema following uneventful appendectomy were published by L. Garner et al (Pulmonary Edema after Appendectomies, APSF Newsletter, Vol. 8, p. 3, Spring 1993). The author asked for thoughts and comments concerning the possible causes of this unexpected complication.
The Hoechst AG, the company producing nitrous oxide in Germany, also received reports about pulmonary complications including two cases with pulmonary edema in patients anesthetized with nitrous oxide.
Investigations made by the company revealed that nitrous oxide also contained traces of methylnitrate, a toxic substance. Supposing that contamination with methylnitrate could have been the cause of these pulmonary complications, II charges (total 330 tons) of nitrous oxide were withdrawn in Germany by the manufacturer.
Contamination of nitrous oxide with methylnitrate (or with other toxic agents) could explain the pulmonary complication in the series of Dr. Garner. The manufacturer should search for such a contamination.
Dr. Med. A. Barankay, Institut fur Anaesthesiologie, Deutsches Herzzentrum Munchen
The Use of the Spray Endotracheal Tube During Emergence from General Anesthesia
1. While patient is still anesthetized, thoroughly suction mouth and pharynx.
2. Deflate cuff.
3. Inject quickly lidocaine .75 mg. to 1.25 mg. per pound (5-10 mi. of 2% lidocaine).
4. Wait 30 seconds and then reinflate cuff.
5. Turn all anesthetic agents off and allow the patient to breathe spontaneously.
6. Extubate with the patient awake at the first sign of inability to tolerate endotracheal tube.
1. Initiate topicalization of the upper airway within three to five minutes of the termination of the surgical procedure.
2. Around 10 minutes after the injection of lidocaine,
one can expect the topical anesthesia to be wearing off gradually. Reinjection
is effective in prolonging the local anesthetic effects, but try lot to
exceed a total dose of 300 mg. of lidocaine.
More 02 During MAC
To the Editor
Regarding the several letters 'On Supplemental Oxygen during MAC' printed in your Spring 1993 issue, we applaud the concern about this hazard. In answer to the drape flammability question raised in one of the letters, in oxygen concentrations above 80%, all drape materials can be ignited by lasers and electrosurgical devices and most can be ignited by electrocautery. (See the following: Surgical Drapes. Health Devices 1986 May; 15[51: 111-37. and Laser ignition of surgical drapes. Health Devices 1992 Jan.; 21111: 15-6).
Also, we have investigated fires during head and neck surgery wherein fractional liter per minute flows of oxygen under the drapes were sufficient to enhance the ignitability of the drapes and patient hair. We recommend that, where possible, air rather than supplemental oxygen be used. Tenting of the drapes to allow gas inflow and outflow is also helpful in addition to gas scavenging. These practices and case studies are presented in "Chapter 37-. Head and Neck Surgical Fires' (in Eisele DW, ed. Complications in head and neck surgery. Mosby, 1993).
In addition, the American Society of Anesthesiologists, at its March 1991 committee meeting on operating room fires, concluded that education of the entire surgical team (i.e., surgeons, anesthesiologists, and nurses) about the fire hazards of surgery is the only practical way of reducing the occurrence of surgical team. It is in that spirit that we send you this letter.
Albert L. de Richemond, M.S., P.E. Senior Project Engineer; Mark E. Bruley, Director Accident and Forensic Investigation Group ECRI
Plymouth Meeting, PA
To the Editor
Having read the Summer 1993 edition of the APSF Newsletter, I felt the need to comment on some of the contents.
1. ETC02 monitoring Such monitoring has been a prerequisite for every general anesthetic done by the undersigned since 1974. 1 do believe it to be one of the most reliable monitoring systems available for anesthesiologists, but I would disagree with any physician who would cancel a case WITHOUT its availability. Perhaps there's a place in a training program for clinical judgement.
2. Disconnecting epidural catheters Disconnecting an epidural catheter is the sole responsibility of the anesthesiologist in charge. Rather than rehash the appropriate cover-up for a mistake, perhaps more attention to correct training would be time better utilized.
3. 'A little potassium' The erroneous dosage of a bolus of potassium seems to have been the result of an attempted mechanical pump administration instead of appropriate "brain power.'
4. "What to do with the older anesthesiologist?" There are many older anesthesiologists who cringe at the younger products of some of today's training centers. Some of these newly trained anesthesiologists come into the work place unable to:
a. do an epidural anesthetic with confidence. b. manage K+ dosage without a pump.
c. manage general anesthesia without a huge
battery of monitors.
d. administer a safe anesthesia for delivery and/or resuscitate a newborn.
These factors bring this critique to the bottom line. Perhaps among all the retired or senior inactive anesthesiologists with a wealth of practical experience and clinical judgement, there may be a reservoir of possibilities to be utilized by teaching institutions for the asking.
Thomas J. Lawton, M.D. La Habra, CA
Are "Older" Anesthesiologists Necessarily Incompetent, as Says "Callow Youth"?
To the Editor
The recent letter by Dr. Kenneth Travis (APSF Newsletter Summer 1993) asked 'What to do with the older anesthesiologist?"
The immediate implication is that of a problem, but what is the supporting documentation? Absent a scientific foundation, the argument must survive the presumption to age discrimination. Age versus youth is not a new debate in the continuum of human experience. Callow youth has always arrogated unto itself such conceits as it could fashion from a world of limited experience and unbridled optimism.
The central issue is not age (or youth), but determining fitness for duty. Is the older anesthesiologist who carries the patina of experience really a greater risk than the recently fledged tyro who grabs every night of call in order to support a mortgage on Xanadu? Is the sum of anesthesiology really only the capacity to successfully process multiple simultaneous signals? That sounds more like the description of a stereo receiver than a skilled clinician.
Even the analogy to the aviation industry, so popular in anesthesiology, fails here. It is only commercial transport aviation that requires the older pilot to retire at age 60; this same pilot may continue, however, to fly a cargo version of the identical plane until such time as the aviator can no longer pass the semi-annual physical exam. General aviation pilots also may continue to fly until no longer able to demonstrate fitness for duty. The Federal Aviation Administration has re-examined its extant policy for air transport pilots in the past and will no doubt do so again in the future. The European Community has recently raised its disqualification ceiling from 60 to 65 years of age for pilots engaged in commercial transportation.
If indeed the specialty can develop methods of detecting decrements in performance, can we not use all our wondrous technology and knowledge then to aid the practitioner who is beset by ill health, age or emotional distress? Humility gained through life experience causes Wordsworth to echo: 'I have learned to look on nature, not as in the hour of thoughtless youth; but hearing oftentimes the still, sad music of humanity.' In a less introspective view, I take solace in the modern aphorism that
'Old age and treachery will always overcome youth and inexperience.'
David Eric Lees, M.D.
Professor and Chairman, Department of Anesthesia Georgetown University Medical Center Washington, D.C.
Is Patient Adequately Sedated?
To the Editor
Hoping to achieve anesthesia immortality, or, at the least, 15 minutes of fame, I would like to propose "Shea's Sign." This is when the lips of the sedated patient go "poof" (or "pouf?!")*, thus indicating that the patient is adequately sedated for the current level of stimulus. I have found it helpful in gauging the level of sedation without asking patients how they are doing, which sometimes wakes them up in the process. With best wishes for improved patient safety.
Karen Shea, M.D. Stevensville, MD
*Webster doesn't seem to recognize either word, but I
trust you will understand what I mean.
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Zaleski L, Abello D, Gold M. The Esophageal Detector Device Does it work? Anesthesiology 1993:79; 244-247.
The detection of an endotracheal tube that has been mistakenly placed into the esophagus is of prime concern to the anesthesiologist. The current American Society of Anesthesiologists Standards for Basic Intraoperative Monitoring require that 'the correct positioning of an endotracheal tube in the trachea must be verified by clinical assessment and by identification of carbon dioxide in the expired gas.' However, this may not always be possible. Electronic equipment for measuring end-tidal C02 may malfunction, the anesthesiologist may be in a location outside the operating room where this equipment is unavailable or the patient may not have a cardiac output sufficient to deliver carbon dioxide to the lungs. Therefore, an alternative means of reliably detecting esophageal intubations would be highly desirable. In 1988, Wee described what he called an esophageal detector device (EDD). This consisted of a 60 ml catheter syringe which was fitted to a catheter mount and attached to the endotracheal tube. If gas could be aspirated into the syringe, the endotracheal tube was felt to be in the trachea. If no gas could be aspirated, then the tube was thought to be in the esophagus. The accuracy of the device is ascribed to the fact that the esophagus is a fibromuscular organ that will collapse when subjected to a negative pressure. However, the trachea has a cartilaginous structure that allows gas to be easily aspirated when a negative pressure is applied. In 1989, Williams and Nunn tested a modified device that used an evacuator bulb and enabled the procedure to be a one-handed operation. They studied 100 patients and were able to correctly identify tracheal or esophageal placement 100% of the time.
Zaleski et al. studied 500 patients to determine the accuracy of an EDD that consisted of an inflatable rubber bulb that was made from an ear/ulcer syringe that was tightly fitted with a plastic 15 mm fitting. The study was divided into three sections. The first group, which consisted of 300 patients, had a standard anesthesia induction and then both the EDD device and capnography were used to determine whether the endotracheal tube was in the esophagus or the trachea. The second group consisted of 100 patients in which the endotracheal tube was purposely placed into the esophagus. Again the accuracy of the EDD was compared with capnography. The third group involved another 100 patients in which a double-blind randomized trial was conducted in which approximately half of the patients had their trachea intubated and the other half had the esophagus intubated. A blinded observer was then asked to use the EDD and capnogram to determine whether the trachea or esophagus had been intubated.
The analysis of the results showed that in all three parts of the study, the EDD correctly identified either tracheal or esophageal intubation and correlated with capnography 100% of the time. Thus, the total sensitivity, specificity and predictive values of this test were 100%. When the endotracheal tube was in the trachea, the bulb usually reinflated in less than 5 seconds. However, in a small percentage of cases, the bulb took up to 30 seconds to fully reinflate. If the bulb did not reinflate by 30 seconds, the tube was deemed to be in the esophagus. The reasons for the delayed reinflation were not clear. The authors speculated that perhaps the bevel of the endotracheal tube impinged on the carina or the wall of the main stem bronchus. The authors cautioned that the device must be tested prior to use on each patient to make sure that it is air tight.
It is indeed rare that a scientific study encompassing some 500 subjects with a total of 681 intubations (500 tracheal and 181 esophageal) produced such dramatic results. Indeed, the fact that the authors had no false positives and no false negatives is truly remarkable. The authors designed an interesting and comprehensive study to demonstrate the utility of this device. Not only is it simple and easy to use, but it can be easily constructed from materials commonly found in the operating room. Although this device is unlikely to replace capnography, it clearly can provide the anesthesiologist the ability to detect esophageal intubations when capnography is not available or in cases where capnography might not be useful such as a cardiac arrest. It seems that this is a device that every anesthesiology department ought to have readily available.
Reviewed by Ian Ehrenwerth, M.D., Professor of Anesthesiology,
Yale University School of Medicine, and a member of the Newsletter Editorial
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by Ellison C. Pierce, Jr., M.D.
This film, with an introduction by Jan Davies, M.D., is a dramatization of a fictional anesthetic catastrophe in a suburban community hospital. Act I, "Catastrophe," begins with Sonya Smith, 35 (married, the mother of two children and an O.R. nurse at the hospital), prepared for a laparoscopic cholecystectomy. Her classification is ASA Physical Status I and the presumption is that tracheal intubation will proceed without difficulty and the procedure without incident. General anesthesia is induced and the circulating nurse begins the abdominal preparation. Within five to ten minutes the patient develops hypotension, becomes hypoxic, and has a cardiac arrest. All efforts fail to resuscitate Sonya and she dies on the table. What went wrong? And why?
Act II recounts the debriefing of the catastrophe and the necessary steps to take following it. The investigation proceeds in Act III; the film concludes with an Epilogue.
Because of the subject matter, this is a must-see film for all anesthesiologists. The virtuoso cast and the expert narration by Paul Springle give a striking sense of reality to the fable of events presented.
Funded by the ASA, 'An Anesthetic Catastrophe' will be distributed by Burroughs-Wellcome in June 1994. Directed by Bob Dilts, the film was shot on location at the Foothills Hospital, Calgary, Alberta. Special thanks go to Muriel Shewchuk, Daniele Sikland, Tim Harmer, Bruce McKenzie, Diane Boudreau, Mark Seland, Paul Rotzinger, the Department of Anaesthesia, the Department of Surgery and the Administration of Foothills Hospital for their help and cooperation in making the videotape.
The scriptwriters were: Dr. J. M. Davies, Calgary, Alberta, Canada; Dr. A. Bacon, Dandenong, Victoria, Australia; Dr. G. Purcell, Sydney, New South Wales, Australia; and Dr. R. A. Caplan, Seattle, WA. GWF Associates, Holmdel, New Jersey, were the producers.
Dr. Pierce, APSF President, is Executive Producer of the ASA Patient Safety Videotape Series.
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The Anesthesia Patient Safety Foundation Newsletter is the official publication of the nonprofit Anesthesia Patient Safety Foundation and is published quarterly at Overland Park, Kansas. Annual membership: Individual $25.00, Corporate $500.00. This and any additional contributions to the Foundation are tax deductible. Copyright, Anesthesia Patient Safety Foundation, 1994
The opinions expressed in this newsletter are not necessarily those of the Anesthesia Patient Safety Foundation or its members or board of directors. Validity of opinions presented, drug dosages, accuracy and completeness of content are not guaranteed by the APSF.
APSF Executive Committee:
Ellison C. Pierce Jr., M.D., President, Burton A. Dole, Jr., Vice-President; David M. Gaba, M.D., Secretary; Casey D. Blitt, M.D., Treasurer; E.S Siker, M.D.; Executive Director; Robert C. Black; Robert A. Caplan, M.D.; Jeffrey 13. Cooper, Ph.D.; Joachim S. Gravenstein, M.D.; W. Dekle Rountree, Jr.
Newsletter Editorial Board:
John H. Eichhorn, M.D., Editor; David E. Lees, M.D. and Gerald L. Zeitlin, M.D., Associate Editors; Stanley J. Aukburg, M.D. Jan Ehrenwerth, M.D., Nancy Gondringer, C.R.N.A.; Jeffrey S. Vender, M. D., Ralph A. Epstein, M.D., Mr. Mark D. Wood.
Editorial Assistant Nola Gibson, Ph.D.
Address all general, membership, and subscription correspondence to:
Anesthesia Patient Safety Foundation
520 N. Northwest Highway
Park Ridge, IL 60068
Address Newsletter editorial comments, questions, letters, and suggestions to:
John H. Eichhorn, M.D. Editor, APSF Newsletter
Department of Anesthesiology
University of Mississippi Medical Center
2500 North State Street
Jackson, MS 39216-4505
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