Evaluation of the NeuroMuscular Junction Using the Single Fiber Electromyography and Reliability of Train-Of-Four in Critically Ill Patients.
Evaluation of the NeuroMuscular Junction Using the Single Fiber Electromyography and Reliability of Train-Of-Four in Critically Ill Patients.
Patients suffering from critical illnesses who are admitted to the Intensive Care Unit (ICU)
 are often affected by multiple organ failure. Among those dysfunctions, it is very important
 to mention the neuromuscular system failure, known as Intensive Care Unit-Acquired Weakness
 (ICU-AW). In non-cooperative patients, the simplified electromyography (called Peroneal Nerve
 Test, PENT) allows diagnosing the Critical Illness Polyneuropathy (CIP) and/or the Critical
 Illness Myopathy (CIM), which are two causes of ICU-AW. The ICU-AW can involve both nerves
 and muscles, but so far there has been no evidence about the involvement of the third element
 of the neuromuscular system: the neuromuscular junction (NMJ). The gold standard technique to
 study the function of the NMJ is the Desmedt test, a particular type of Electroneurography
 (ENG); the Single Fiber Electromyography (SF-EMG ) might be a valid and more sensitive
 technique for this analysis. The spreading use of Neuromuscular Blocking Agents (NMBAs) has
 led to the introduction of the Train-Of-Four acceleromyography (TOF) monitoring in ICU;
 however, there is a lack of information on its reliability in critically ill patients.

 Some conditions related to critical illness, like the ICU-AW, could make TOF monitoring
 unreliable.

 The aims of the study are:

 1. To estimate the prevalence of NMJ disorders acquired during critical illnesses using
 SF-EMG.

 2. To assess the reliability of TOF in critically ill patients. The study will evaluate
 patients with critical illnesses hospitalised in the General Intensive Care Unit (UOC
 Anestesia e Rianimazione 2, Spedali Civili di Brescia). To diagnose CIP and/or CIM, PENT
 will be performed after 72 hours from the admission in the ICU and every 72 hours. To
 evaluate NMJ disorders, SF-EMG will be performed in patients with an abnormal PENT. To
 evaluate the reliability of TOF, the test will be performed before, during and after
 NMBAs treatment and in all studied patients, independently from NMBAs administration;
 the presence of neuromuscular blockade will be evaluated clinically and/or using
 instrumental tests like Desmedt test. Statistical analysis will be performed to
 represent the prevalence of NMJ disorders in the general intensivistic population and
 the reliability of TOF in terms of specificity and sensitivity for the diagnosis of the
 neuromuscular blockade.
COMPLETE TITLE OF THE STUDY: EVALUATION OF THE NEUROMUSCULAR JUNCTION USING THE SINGLE FIBER
 ELECTROMYOGRAPHY AND RELIABILITY OF TRAIN-OF-FOUR IN CRITICALLY ILL PATIENTS. Author and
 responsible for the study: Dr. Matteo Filippini Sponsor: ASST Spedali Civili di Brescia -
 Italy

 1. RATIONALE OF THE STUDY Patients suffering from critical illnesses who are admitted to
 the Intensive Care Unit (ICU) are often affected by multiple organ failure. Among those
 dysfunctions, it is very important to mention the neuromuscular system failure, known as
 Intensive Care Unit-Acquired Weakness (ICU-AW). In non-cooperative patients, the
 simplified electromyography (called Peroneal Nerve Test, PENT) allows diagnosing the
 Critical Illness Polyneuropathy (CIP) and/or the Critical Illness Myopathy (CIM), which
 are two causes of ICU-AW. The ICU-AW can involve both nerves and muscles, but so far
 there has been no evidence about the involvement of the third element of the
 neuromuscular system: the neuromuscular junction (NMJ). The gold standard technique to
 study the function of the NMJ is the Desmedt test, a particular type of
 Electroneurography (ENG); the Single Fiber Electromyography (SF-EMG ) might be a valid
 and more sensitive technique for this analysis. The spreading use of Neuromuscular
 Blocking Agents (NMBAs) has led to the introduction of the Train-Of-Four
 acceleromyography (TOF) monitoring in ICU; however, there is a lack of information on
 its reliability in critically ill patients. Some conditions related to critical illness,
 like the ICU-AW, could make TOF monitoring unreliable.

 2. STUDY AIMS A. To estimate the prevalence of NMJ disorders acquired during critical
 illnesses using SF-EMG. B. To assess the reliability of TOF in critically ill patients.

 3. POPULATION Target population: patients with critical illnesses hospitalised in the
 General Intensive Care Unit (UOC Anestesia e Rianimazione 2, Spedali Civili di Brescia).
 Inclusion criteria: adult patients (18-year-old and older ones) hospitalised in ICU. In
 order to realise the first aim of the study, patients with a pathologic PENT will be
 evaluated. In order to realise the second aim of the study, patients who receive NMBAs
 will be evaluated; patients who do not receive NMBAs will also be evaluated, as a
 control group.

 Exclusion criteria:

 -  patients with a terminal disease;

 -  patients with an ICU-length-of-staying perspective less than 72 hours;

 -  patients with a chronic disease associated with known neuropathy or myopathy;

 -  patients treated with drugs that may cause neurotoxicity and myotoxicity;

 -  patients with primary or secondary acute Peripheral Nervous System (PNS) lesions or
 muscle lesions;

 -  patients with prosthesis, wounds or other conditions that prevent
 electrophysiological testing.

 4. STUDY DESIGN Observational, prospective, cohort study; retrospective analysis of
 prospectively collected data.

 5. OPERATIVE PROCEDURES

 -  to diagnose CIP and/or CIM, PENT will be performed after 72 hours from the
 admission in the ICU and every 72 hours.

 -  to evaluate NMJ disorders, SF-EMG will be performed in patients with an abnormal
 PENT.

 -  to evaluate the reliability of TOF, the test will be performed before, during and
 after NMBAs treatment and in all studied patients, independently from NMBAs
 administration; the presence of the neuromuscular blockade will be evaluated
 clinically and/or using instrumental tests like Desmedt test.

 PROCEDURES:

 SIMPLIFIED ELECTROMYOGRAPHY (EMG) The simplified EMG is called Peroneal Nerve Test
 (PENT), and it consists in measuring the compound muscle action potential (CMAP) of a
 single peroneal nerve (if the first peroneal nerve tested is pathologic) or of both
 peroneal nerves (if the first nerve is healthy). ICU-AW is diagnosed in case of
 reduction of CMAP under the usual cutoff (calculated as two standard deviations from the
 average laboratory value). SF-EMG - SINGLE FIBER ELECTROMYOGRAPHY The Single Fiber
 Electromyography (SF-EMG) is a test which studies action potentials of single muscular
 fibre. It allows the study of muscular fibres microphysiology, and it investigates early
 alterations (sometimes preclinical) of NMJ, typical of Myasthenia Gravis. The needle
 electrode for the single fibre analysis is composed of a small registration surface, and
 this is the cathode, while a second electrode is the anode. The muscle action potential
 registration follows the tested muscles activation and this activation can be voluntary
 (voluntary SF-EMG) or through stimulation (stimulated SF-EMG), with a stimulation
 frequency of 2-10 Hz, an intensity of 10-20 mA and a duration between 10-50 ms. The
 variation in the time interval between two action potentials of the same motor unit is
 called "jitter". SF-EMG measures the variation of this inter potential interval
 (jitter), which can be increased in patients with NMJ diseases. TOF - TRAIN-OF-FOUR
 ACCELEROMYOGRAPHY The TOF acceleromyography consists in the consecutive application of
 four electrical stimuli (generally 200 ms, 50 mA) through the course of the ulnar nerve
 and in the recording of the induced thumb acceleration; the result of this test is
 expressed as the ratio of the fourth to the first magnitude of the response. If the
 ratio is greater than 90%, the response will be considered normal, and the clinical
 meaning of this finding is that the patient is not (or no more) under the effect of
 NMBAs. Conversely, if the ratio is less than 90%, the clinical meaning is that the
 patient is under the effect of non-depolarising NMBAs. TOOLS Paper and electronic
 detection boards. OTHER EVALUATIONS Collection of clinical data useful for describing
 the status of the investigated population. DATA MANAGEMENT Electrophysiological
 measurements data conducted to the patient's bed will be integrated with
 clinical-physical and laboratory data ordered in a worksheet (progressive number,
 diagnosis, initials, age, sex, weight, height, BMI, days of hospitalization, length of
 staying in the ICU, previous surgical procedures, inflammation indexes, liver and kidney
 function indexes, coagulation function indexes, mechanical ventilation mode, simplified
 acute physiology score II [SAPS II] and sequential order failure assessment [SOFA]
 score). Data collection: data will be collected daily by the principal investigator, as
 well as by students and resident physicians involved in the project and previously
 provided with appropriate authorisation to attend the centre for training purposes.
 Rules on personal data management: see the next point for the respect of privacy.
 Operational methods of data management: recording of data on paper and/or electronic
 card without uploading to file, management of electronic archives or linkage procedures
 with other databases.

 6. STATISTICAL ANALYSIS AND METHODS

 A descriptive statistical analysis will be performed to represent:

 A. The characteristics of the population: number of subjects, sex, age, body mass index
 (BMI), Glasgow Come Score (GCS), SOFA score and SAPS II, days of hospitalization in ICU,
 reason for admission to ICU, use of amines, presence and severity of the infectious
 state. In particular:

 -  Qualitative variables (e.g. sex, disease) will be expressed as mode and frequency
 distribution.

 -  Ordinal quantitative variables (e.g. GCS) will be expressed as median and
 interquartile range.

 -  Continuous quantitative variables (e.g. age, BMI) will be expressed as mean and
 standard deviation.

 B. The results of the applied diagnostic tests:

 -  the result of the PENT will be expressed as the magnitude of the potential (mV);

 -  the result of the SF-EMG will be expressed as the variation in the time interval
 between the two action potentials of the same motor unit (jitter) (msec)

 -  the result of the TOF will be expressed as the ratio of the fourth response
 magnitude to the first one. An inferential statistical analysis will be performed
 to represent the prevalence of NMJ disorders in the general intensivistic
 population and the reliability of TOF in terms of specificity and sensitivity for
 the diagnosis of the neuromuscular blockade. SAMPLE SIZE The investigator's
 hypothesis is that NMJ disorders in the study population are non-existent or in any
 case epidemiologically irrelevant: therefore a sample of 73 patients with a
 negative test will allow affirming that the prevalence of that disorder is less
 than 10%. If one or more SF-EMG tests are positive, the prevalence of NMJ disorders
 will be calculated from those results with a 95% confidence interval. After the
 enrolment of 35 patients studied with SF-EMG, an ad-interim analysis will be
 performed, and the prevalence of NMJ disorders will be estimated by an exact
 binomial test, and the 95% confidence interval will be calculated. In order to
 realise the second aim of the study (to assess the reliability of TOF in critically
 ill patients) a sample of 85 patients will allow estimating sensitivity and
 specificity with a precision of 10% under the realistic hypothesis that they are
 100% and 90% respectively.

 7. ETHICAL ASPECTS The study, being observational, will not entail, in itself, any risk for
 any patient. The data of the patients included in the study will be physical-technical
 (PENT and SF-EMG tests) and clinical-laboratoristic. They will be obtained from standard
 clinical practice. The investigator will proceed to exhaustive information about the
 nature of the study and the operations of analysis towards patients; the same patients,
 made aware of the nature of the collected data, will be required to express the informed
 consent, according to the regulations in force. In the case of patients unable to give
 valid consent, data collection and processing will only take place after the patients
 themselves have regained their lost capacity and have given consent or after this has
 been done by legal representatives. The study does not alter the risk/benefit ratio of
 the procedures used for data acquisition; concerning the specific acts of the study,
 this ratio is zero. This study will be conducted in accordance with this protocol, with
 the principles of good clinical practice in accordance with the International Conference
 on Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH GCP)
 guidelines and ethical principles set out in the Helsinki Declaration.

 8. INFORMATION TO THE PATIENT AND CONSENT The patients will express their informed consent
 to the conduct of the study and the management of sensitive data by signing their own
 form on the specially prepared forms. In the case of patients lacking the ability to act
 and for which there is a legal representative, the informed consent will be given by the
 latter. The informative note before the acquisition of consent will be provided by the
 principal investigator.

 9. APPROVAL BY THE RESPONSIBLE ETHICS COMMITTEE The documents of the study were reviewed
 and approved by the responsible Ethics Committee (Comitato Etico di Brescia, NP2963).

 10. CONFIDENTIALITY OF DATA AND PRIVACY The confidentiality of the collected data (including
 laboratory data) will be maintained through the rigorous conservation of data collection
 cards by the investigators and the patients involved will be identified with codes that
 guarantee anonymity, even in order to comply with the privacy of the subjects, according
 to the law in force.

 11. DATA PROPERTY The ownership of the data related to the study, its execution and its
 results belong to the sponsor.

 12. PUBLICATION OF RESULTS The investigator reserves the right to publish the results of the
 study through works published in specialised journals whose editorial policies respect
 the laws in force, with particular reference to the anonymity of the data.

 13. CONSERVATION OF STUDY DOCUMENTS All information related to the study participants,
 including data collection forms, documentation "source" (in addition to the medical
 records already stored by the hospital), all clinical and laboratory data used for the
 study, as well as all the documentation concerning the submission and approval by the
 Ethics Committee, the informed consent and all the regulatory documentation, etc. will
 be kept by the investigators in a safe and accessible place for possible inspections.
Inclusion Criteria:

 Adult patients (18-year-old and older ones) hospitalised in ICU. In order to realise the
 first aim of the study (to estimate the prevalence of NMJ disorders acquired during
 critical illnesses using SF-EMG), patients with a pathologic PENT will be evaluated. In
 order to realise the second aim of the study (to assess the reliability of TOF in
 critically ill patients. The study will evaluate patients with critical illnesses
 hospitalised in the General Intensive Care Unit), patients who receive NMBAs will be
 evaluated; patients who do not receive NMBAs will also be evaluated, as a control group.

 Exclusion Criteria:

 -  patients with a terminal disease;

 -  patients with an ICU-length-of-staying perspective less than 72 hours;

 -  patients with a chronic disease associated with known neuropathy or myopathy;

 -  patients treated with drugs that may cause neurotoxicity and myotoxicity;

 -  patients with primary or secondary acute Peripheral Nervous System (PNS) lesions or
 muscle lesions;

 -  patients with prosthesis, wounds or other conditions that prevent electrophysiological
 testing.