Effect of depth of neuromuscular block on intraoperative surgical conditions as determined by the Leiden Surgical Rating Scale in morbidly obese patients undergoing laparoscopic bariatric surgery

ASA 1-3, 18 years or older and younger than 66 years; BMI > 34 kg/m2; ability to give informed consent; elective bariatric surgery

known or suspected neuromuscular disorders impairing neuromuscular function; allergies to muscle relaxants, anesthetics or narcotics; a (family) history of malignant hyperthermia; women who are or may be pregnant or are currently breast feeding; renal insufficiency, as defined by serum creatinine x 2 of normal, or urine output < 0.5 ml/kg/h for at least 6 h. When available, other indices will be taken into account as well such as glomerular filtration rate < 30 ml/h and proteinuria (a ratio of 30 mg albumin to 1 g of creatinine).