Evaluation of Intravenous Lidocaine and Time to Regression of the Sensory Block After Spinal Anesthesia (ELSA Trial)
Evaluation of Intravenous Lidocaine and Time to Regression of the Sensory Block After Spinal Anesthesia (ELSA Trial)
The use of intravenous lidocaine in continuous infusion in the perioperative period is
 associated with a reduction in postoperative pain scores, opioid use, incidence of nausea and
 vomiting, among other favorable outcomes. However, this therapeutic intervention has not yet
 been adequately evaluated by clinical trials when associated with regional anesthesia. The
 aim of this study is to evaluate whether the use of intravenous lidocaine in continuous
 infusion during spinal anesthesia with isobaric bupivacaine alters the time to regression of
 sensory block in patients undergoing surgical procedures for the treatment of bone and
 connective tissue tumor surgeries. This will be a triple-blind randomized trial. The sample
 size estimated was 66 patients. The study will include all patients who meet the
 pre-established inclusion and exclusion criteria, choose to participate, and agree with the
 Informed Consent Form. The main anesthetic technique will be spinal anesthesia with 13 mg of
 isobaric bupivacaine. Patients will be allocated in two groups in a blindly after
 randomization: Group S (lidocaine 0.75mg.kg-1 in bolus followed by infusion of saline
 solution) and Group L (lidocaine 1.5 mg.kg-1 followed by continuous infusion of lidocaine
 solution at 2 mg.kg-1.h-1). The primary outcome will be the time to T12 regression of the
 sensory block. Will also be evaluated: time to regression of the motor block, most rostral
 dermatome achieved by the sensory block, time to two-segment regression oh the sensory block,
 propofol dose in the operating room, postoperative pain score at rest, pain at movement
 score, quality of recovery, use of opioids in the postoperative period, nausea or vomiting,
 dizziness, shivering, arrhythmias, hypotension, urinary retention, and length of stay. The
 records will be assigned to the RedCap database. The data will be extracted without
 identification of the allocation groups for the R software and the groups will be revealed to
 the researcher after the end of the statistical analysis to write the summary of the results.
 The results will be submitted to scientific journals afterward.
Hypotheses:

 Null hypothesis

 H0: The time to T12 regression of the sensory block after administration of isobaric
 bupivacaine is EQUAL with or without the use of intravenous lidocaine in continuous infusion.

 Alternative hypothesis

 H1: The time to T12 regression of the sensory block after administration of isobaric
 bupivacaine is DIFFERENT depending on the use or not of intravenous lidocaine in continuous
 infusion.

 Methods

 Study design

 It is a randomized, controlled, triple blind clinical trial (patient, assistant team /
 investigator, and data collection/analysis).

 Standard procedures

 All patients should undergo an outpatient preoperative evaluation with an anesthesiologist.
 At that moment, eligibility for the study will be evaluated and the informed consent form
 will be presented. The preoperative form will also be completed by the investigator of the
 study who includes the patient of the patient.

 Study participants will undergo continuous 5 leads electrocardiographic, automated
 noninvasive blood pressure and capnography monitoring initiated at the entrance to the
 operating room. Peripheral venous access will also be obtained. After certification of
 monitoring and venous access the patient will be positioned in lateral decubitus with the
 side to be performed the surgery (or the side of higher major surgical trauma in case of
 bilateral procedures) superiorly (e.g. surgery with right side of the body the puncture will
 be performed in left lateral decubitus) and then will be initiated the infusion the solutions
 present in the syringe and in the bag sent by the Division of Pharmacy of the hospital unit
 according to the protocol. Immediately after the initiation of continuous infusion of the
 solution the anesthesiologist will begin preparation for performing subarachnoid puncture
 with a Quinke needle between 22 and 27 Gauge (preferably 26 Gauge) between spaces L4-L5 and
 L2-L3 (preferably L3-L4) depending on the assessment of the anesthesiologist responsible for
 the predicted difficulty for the block and the risk of post-dural puncture headache.
 Conscious sedation with propofol in continuous infusion and local anesthesia with 1%
 lidocaine solution up to 100 mg will also be initiated. It will be administered in the
 subarachnoid space 13mg (2.6 ml of solution) of isobaric bupivacaine at 0.5%.

 As a multimodal and antiemetic analgesia regimen, the following will be administered:

 -  dexamethasone 4mg in the operating room;

 -  ondansetron 4mg in the operating room and in case of postoperative nausea or vomiting;

 -  dipyrone 20mg.kg-1 every 4 hours or paracetamol 500mg every 4 hours (in case of dipyrone
 allergy) started before regional anesthesia and kept until discharge;

 -  tenoxicam 40mg in the OR and 20 mg on the first postoperative day, unless
 contraindicated by the assistant team;

 -  tramadol 50mg up to every 4 hours or morphine 4 mg up to every 10 minutes in case of
 pain assessed by verbal numerical scale greater than or equal to 4 (0-10) or according
 to evaluation of the assistant team.

 After the block, evaluations of the extension of sensory and motor block will be performed at
 minutes 5, 10, 15 and then every 15 minutes as presented in the data collection form . The
 sensory block will be evaluated by pinprick sequentially from the most caudal to the most
 cephalic level, at the midclavicular line, on the opposite side of the surgical procedure (or
 on the side of minor surgical trauma in case of bilateral procedures) and will be computed as
 the level of blockade the point at which the patient reports sensitivity similar to reference
 point (homolateral shoulder) will be computed. Motor block will be initially evaluated for
 ankle flexion, followed by knee elevation and finally leg elevation with knees extended, and
 the level of motor block will be recorded according to the modified Bromage scale on the
 opposite side of the surgical procedure (or on the side of lower surgical trauma in case of
 bilateral procedures).

 The patient will be released for the surgical procedure as soon as he reaches motor block
 evidenced by a modified Bromage scale equal to 2. During the procedure, only sensory block
 will be observed so that there is no interference with the surgical procedure. After the end
 of the procedure, each 15 minutes evaluations of sensory and motor block will be performed.
 Supplementary sensory and motor status evaluations may be performed in addition to the
 evaluations every 15 minutes at the discretion of the assistant team. After the end of the
 surgery. Sensory block and motor block will be evaluated concomitantly until the primary
 outcome (regression of sensory block up T12 dermatome), regression of motor block to modified
 Bromage 1 and regression of two dermatomes of the sensory block (secondary outcomes) are
 achieved.

 The patient will be continuously evaluated in the post-anesthetic recovery room until at
 least the second postoperative hour and until the primary outcome. Twenty-four hours after
 the end of the procedure, the patient will be reevaluated at the ward, or by phone contact in
 case of discharge, and the study information and questionnaires will be computed as described
 in the data collection form.

 Intervention

 The bolus and infusion of the solution referring to the allocated group will be made:

 -  After monitoring and obtaining venous access

 -  Prior to the initiation of continuous propofol infusion and spinal puncture

 Group L (Lidocaine):

 Lidocaine bolus 1.5 mg.kg-1 intravenous before the onset of lidocaine infusion.

 Lidocaine 2mg.kg-1.h-1.

 Group S (saline solution):

 Lidocaine bolus 0.75 mg.kg-1 intravenous before the onset of saline infusion.

 Saline solution.

 Group L will be sent a 20 ml syringe of 2% lidocaine and 200 ml of lidocaine solution at
 8mg.ml-1 (80ml of 2% lidocaine associated with 120ml 0.9% sodium chloride) Group S will be
 sent a 20 ml syringe of 1% lidocaine and 200 ml of saline solution (0.9% sodium chloride)

 A syringe with 20 ml of solution and a bag with 200 ml of solution indistinguishable between
 the groups, with the identification of the patient by label prepared specifically for the
 study will be prepared by the Pharmacy personal. The bag and the solution will be sealed in a
 waterproof and opaque envelope and sent to the Operating Theatre (OT). The envelope will be
 stored in the refrigerator of the sector between 3º C and 8º C until the patient is sent to
 the operating room, when the drugs will be sent to the operating room. At the time designated
 for the start of the intervention, a bolus of 0.075 ml.kg-1 of the syringe solution, followed
 by 0.25 ml.kg-1.h-1 in the infusion pump of the solution in the bag will be administered.

 Continuous infusion of lidocaine (group L) or saline solution (group S) will be maintained
 until the sensory block regresses to the T12 level, until the regression of 2 dermatomes of
 the sensory block and until the motor block reaches the score on the modified Bromage scale
 1.

 The infusion will be interrupted and the masking will be broken in case of:

 -  severe neurological disorders (e.g. seizure, respiratory depression);

 -  cardiac (e.g. atrioventricular block greater than second degree, bradycardia with HR
 less than 40 bpm not responsive to atropine, refractory hypotension);

 -  other unforeseen clinical changes that pose a risk to the patient.

 The infusion will be maintained until the end of anesthesia and masking in case of need for
 conversion to general anesthesia (e.g., insufficient block, psychomotor agitation) and the
 patient will be (1) censored for the outcomes related to the extension of the blockade and
 (2) will continue contributing to the other outcomes.

 Collected variables

 The variables evaluated in the study will be collected preoperatively, at the operating room,
 at the PACU, in the first 24 postoperative hours, and in 30 days and recorded in the RedCap
 database. All data collected in the study is available at the data collection sheets.

 Statistical analysis

 Medical records numbers and names will be included in the data collection but will not be
 imputed in RedCap. Therefore, the participants' data will not be revealed at the time of data
 extraction and analysis, preserving the anonymity of the research individuals.

 The data extracted from RedCap will be analyzed in software R. The groups will be separated
 by intervention group, but the researcher responsible for the analysis will only have access
 to the groups after the end of the analysis of the results.

 Continuous variables will be presented as mean and standard deviation or median and
 interquartile range depending on their distribution. To check the comparability between the
 groups and study, the basal covariates will be presented by intervention group. Bivariate
 statistical tests will be performed bicaudal chi-squared test, t-test, nonparametric
 Mann-Whitney test and log rank test depending on the characteristics of the variable. In the
 outcome "most rostral dermatome achieved by sensory block" each dermatome will be numbered
 for statistical analysis from S5 to C6 according to the following examples: S5=1, S4=2, S3=3,
 C8=23, C7=24 and C6=25 and will be analyzed according to its distribution. The primary
 outcome will be presented graphically by the Kaplan Meier curve. The value of α was set at
 0.05. For the primary outcome, the p-value will be analyzed without adjustment for multiple
 tests. Secondary outcomes will be evaluated without adjustment for multiple comparisons
 because it is an exploratory analysis.

 The sample size was calculation was performed with the software R, package 'WMWssp', command
 'WMWssp'. Based on previous studies, the mean time for regression was estimated at 120
 minutes standard deviation for sensory block regression after subarachnoid anesthesia with
 bupivacaine in 20 minutes. Adopting the α value of 0.05, the power of 80%, and a 10% drop out
 rate, the estimated sample size to demonstrate the difference of 15 minutes in the primary
 outcome was 66 patients (R software input: 'WMWssp(round(rnorm(1000000, 120, 20)),
 rnorm(1000000, 135, 20), alpha = 0.05, power = 0.8, t = 1/2, simulation = FALSE, nsim =
 10^4)').
Inclusion Criteria:

 -  Age between 18 and 85 years-old

 -  The American Society of Anesthesiologists (ASA) physical status classification from I
 to III

 -  To be submitted to:

 -  - Spinal Anesthesia

 -  - For surgeries performed by the Bone and Connective Tissue (TOC) service

 -  - Involving lower limbs and inguinal region requiring sensory block level up to the
 T12 dermatome (except for larger amputations and bone resections)

 -  - Expected duration of less than 120 minutes

 -  - In supine position

 -  That they voluntarily decide to participate in the study

 Exclusion Criteria:

 -  Coagulation disorder that prevents the execution of the blockade:

 -  - International normalized ratio for prothrombin (INR) time and activity > 1.5

 -  - Activated partial thromboplastin time ratio (PTTa) >1.5

 -  - Use of enoxaparin up to 40mg/day less than 12h before the procedure

 -  - Use of enoxaparin above 40mg/day less than 24hours before the procedure

 -  - Use of oral anticoagulant or platelet aggregation inhibitors in a lower interval
 than recommended for spinal block

 -  - Other coagulation disorders that prevent spinal anesthesia

 -  Moderate or severe left ventricular systolic dysfunction (defined by the presence of
 left ventricle ejection fraction below 40%)

 -  Sinus bradycardia (FC < 50 beats per minute)

 -  Relevant cardiac conduction system disorders (e.g. atrium ventricular block greater
 than first-degree, Wolf-Parkinson-White syndrome)

 -  Clinically significant arrhythmia (e.g. atrial fibrillation)

 -  Body mass index (BMI) than > 35 mg.kg-1

 -  Previous diagnosis of liver cirrhosis

 -  Creatinine clearance < 30 ml/min/1.73m2 estimated by the method of the Modification of
 Diet in Renal Disease (MDRD) study group

 -  Infection at the site of lumbar puncture

 -  Previous spinal surgery

 -  Allergy to local anesthetics amino-amides

 -  Difficulty in communication, understanding or cognitive deficit that prevents adequate
 oral response to study the study forms

 -  Pre-existing neurological lesion in topography to be evaluated motor block

 -  Documented or suspected spinal or central nervous system metastasis

 -  Regular use of strong opioids at a dose equal or greater than 60 mg of oral morphine
 equivalents per day

 -  Desire to withdraw from the study at any time of its execution