Observational Study in Bariatric Surgery

Study Overview
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Brief Summary
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Obesity in the world represents a growing share of the general population. At hospital, the management of these patients could be problematic especially when calculating the drug dosage. According to the French guidelines, neostigmine, a cholinesterase inhibitor, should be used to reverse a residual neuromuscular blockade at a dose of 0.4 mg/kg of total body weight in non-obese patients. In morbidly-obese patients, with the modification of the fat/lean mass ratio, the optimal dose of neostigmine is non-consensual. To calculate the dose of neostigmine, some anesthesiologists use the total body weight, others use the ideal body weight and others use the adjusted body weight. Due to this practice variability, It may be useful to observe the mean time to recovery of neuromuscular blockade and side effects after pharmacological reversal according to the dosage of neostigmine.

Official Title
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Observational Study of the Pharmacological Reversal of the Residual Neuromuscular Blockade in Bariatric Surgery

Conditions
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Obesity, Neostigmine, Residual Neuromuscular Blockade

Intervention / Treatment
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* Other: NO INTERVENTION, it is an observational study


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria*: Adult obese patients (≥ 18 years and BMI ≥ 35 Kg/m²), both sexes Any elective bariatric surgery Neuromuscular blockade with rocuronium Maintenance of anesthesia with a halogenated agent Free patient, without guardianship or subordination Patients with a social security coverage No opposition given by the patient after clear and fair information Exclusion Criteria*: Patients with hypersensitivity to the active substance or to other derivatives, or to any of the excipients of neostigmine, Emergency surgery, Severe renal and / or hepatic insufficiency, Persons benefiting from enhanced protection, namely pregnant women, breastfeeding women, persons deprived of their liberty by a judicial or administrative decision, persons staying in a health or social institution, adults under legal protection and finally sick people in emergency situation.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Ideal Body Weight<br>groups of patients divided according to neostigmine dose weight, ideal body weight (IBW) | Other: NO INTERVENTION, it is an observational study<br>* No intervention<br>|
| Total Body Weight<br>groups of patients divided according to neostigmine dose weight, total body weight (TBW), | Other: NO INTERVENTION, it is an observational study<br>* No intervention<br>|
| Adjusted Body Weight<br>groups of patients divided according to neostigmine dose weight, , adjusted body weight (ABW) | Other: NO INTERVENTION, it is an observational study<br>* No intervention<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compare the mean delay to recovery of neuromuscular blockade after pharmacological reversal according to the dosage of neostigmine administered to the patient (on TBW, IBW or ABW | Delay between the injection of neostigmine T0 and obtain a ratio between the 4th and the 1st response (T4/T1) by Four-Train Stimulator (TOF) ≥ 0.9 | Few minutes after injection of neostigmine | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compare the frequence of side effects according to the dosage of neostigmine administered (on TBW, IBW or ABW) | Occurrence of bradycardia defined by a heart rate <50 beats per minute in the hour following the injection of neostigmine Occurrence of bronchospasm defined by a desaturation over 92% and sibilants to the auscultation within one hour after neostigmine injection. | Within one hour after the injection of neostigmine |