Spontaneous recovery of neuromuscular blockade is an independent risk factor for postoperative pulmonary complications after abdominal surgery

BACKGROUND In intermediate-to-high-risk patients, major abdominal surgery is associated with a high incidence of postoperative complications, mainly pulmonary. Neuromuscular blocking drugs have been suggested as a contributing factor, but this remains unproven. OBJECTIVE To define the relationship of neuromuscular blockade management (reversal) with postoperative pulmonary complications (PPCs). DESIGN The individualised PeRioperative Open-lung approach Versus standard protectivE ventilation in abdominal surgery study was a prospective, multicentre, four-arm, randomised controlled trial. This is a secondary analysis of the data. SETTING Twenty-one teaching hospitals in Spain. The study was conducted between 2 January 2015, and 18 May 2016. PATIENTS Age more than 18 years with an intermediate-to-high risk for PPCs, scheduled for major abdominal surgery lasting more than 2 h. Exclusion criteria included pregnancy or breastfeeding, and moderate-to-severe organ diseases. INTERVENTIONS The mode of reversal of neuromuscular blockade determined two patient groups: pharmacological reversal versus spontaneous recovery. MAIN OUTCOME MEASURES The primary outcome was a composite of PPCs during the first 30 postoperative days. The association between categorical variables and PPCs within 30 days was studied. Univariate and multivariable logistic regression modelling and propensity score analyses were performed. RESULTS From the 923 patients included, 596 (64.6%) presented with PPCs within 30 days after surgery. Patients who developed these complications were older with a higher BMI, a lower pre-operative SpO 2 , a higher ASA physical status score and a higher incidence of arterial hypertension, diabetes mellitus or chronic obstructive pulmonary disease. Pharmacological neuromuscular blockade reversal was associated with a lower incidence of PPCs (odds ratio 0.62, 95% CI 0.47 to 0.82). CONCLUSION Spontaneous recovery of neuromuscular blockade was an independent risk factor for PPCs in patients with intermediate-to-high risk, undergoing abdominal surgery. We suggest this factor should be included in future studies on PPCs. TRIAL REGISTRATION clinicaltrials.gov identifier: NCT02158923.