Association between night-time surgery and occurrence of intraoperative adverse events and postoperative pulmonary complications

Background: The aim of this post hoc analysis of a large cohort study was to evaluate the association between night-time surgery and the occurrence of intraoperative adverse events (AEs) and postoperative pulmonary complications (PPCs). Methods: LAS VEGAS (Local Assessment of Ventilatory Management During General Anesthesia for Surgery) was a prospective international 1-week study that enrolled adult patients undergoing surgical procedures with general anaesthesia and mechanical ventilation in 146 hospitals across 29 countries. Surgeries were defined as occurring during ‘daytime’ when induction of anaesthesia was between 8:00 AM and 7:59 PM, and as ‘night-time’ when induction was between 8:00 PM and 7:59 AM. Results: Of 9861 included patients, 555 (5.6%) underwent surgery during night-time. The proportion of patients who developed intraoperative AEs was higher during night-time surgery in unmatched (43.6% vs 34.1%; P<0.001) and propensity-matched analyses (43.7% vs 36.8%; P=0.029). PPCs also occurred more often in patients who underwent night-time surgery (14% vs 10%; P=0.004) in an unmatched cohort analysis, although not in a propensity-matched analysis (13.8% vs 11.8%; P=0.39). In a multivariable regression model, including patient characteristics and types of surgery and anaesthesia, night-time surgery was independently associated with a higher incidence of intraoperative AEs (odds ratio: 1.44; 95% confidence interval: 1.09–1.90; P=0.01), but not with a higher incidence of PPCs (odds ratio: 1.32; 95% confidence interval: 0.89–1.90; P=0.15). Conclusions: Intraoperative adverse events and postoperative pulmonary complications occurred more often in patients undergoing night-time surgery. Imbalances in patients’ clinical characteristics, types of surgery, and intraoperative management at night-time partially explained the higher incidence of postoperative pulmonary complications, but not the higher incidence of adverse events. Clinical trial registration: NCT01601223

The LAS VEGAS risk score for prediction of postoperative pulmonary complications An observational study

BACKGROUND Currently used pre-operative prediction scores for postoperative pulmonary complications (PPCs) use patient data and expected surgery characteristics exclusively. However, intra-operative events are also associated with the development of PPCs.OBJECTIVE We aimed to develop a new prediction score for PPCs that uses both pre-operative and intra-operative data.DESIGN This is a secondary analysis of the LAS VEGAS study, a large international, multicentre, prospective study.SETTINGS A total of 146 hospitals across 29 countries.PATIENTS Adult patients requiring intra-operative ventilation during general anaesthesia for surgery.INTERVENTIONS The cohort was randomly divided into a development subsample to construct a predictive model, and a subsample for validation.MAIN OUTCOME MEASURES Prediction performance of developed models for PPCs.RESULTS Of the 6063 patients analysed, 10.9% developed at least one PPC. Regression modelling identified 13 independent risk factors for PPCs: six patient characteristics [higher age, higher American Society of Anesthesiology (ASA) physical score, pre-operative anaemia, pre-operative lower SpO(2) and a history of active cancer or obstructive sleep apnoea], two procedure-related features (urgent or emergency surgery and surgery lasting >= 1 h), and five intraoperative events [use of an airway other than a supraglottic device, the use of intravenous anaesthetic agents along with volatile agents (balanced anaesthesia), intra-operative desaturation, higher levels of positive end-expiratory pressures > 3 cmH(2)O and use of vasopressors]. The area under the receiver operating characteristic curve of the LAS VEGAS risk score for prediction of PPCs was 0.78 [95% confidence interval (95% CI), 0.76 to 0.80] for the development subsample and 0.72 (95% CI, 0.69 to 0.76) for the validation subsample.CONCLUSION The LAS VEGAS risk score including 13 peri-operative characteristics has a moderate discriminative ability for prediction of PPCs. External validation is needed before use in clinical practice

Epidemiological characteristics, practice of ventilation, and clinical outcome in patients at risk of acute respiratory distress syndrome in intensive care units from 16 countries (PRoVENT): an international, multicentre, prospective study

Background Scant information exists about the epidemiological characteristics and outcome of patients in the intensive care unit (ICU) at risk of acute respiratory distress syndrome (ARDS) and how ventilation is managed in these individuals. We aimed to establish the epidemiological characteristics of patients at risk of ARDS, describe ventilation management in this population, and assess outcomes compared with people at no risk of ARDS. Methods PRoVENT (PRactice of VENTilation in critically ill patients without ARDS at onset of ventilation) is an international, multicentre, prospective study undertaken at 119 ICUs in 16 countries worldwide. All patients aged 18 years or older who were receiving mechanical ventilation in participating ICUs during a 1-week period between January, 2014, and January, 2015, were enrolled into the study. The Lung Injury Prediction Score (LIPS) was used to stratify risk of ARDS, with a score of 4 or higher defining those at risk of ARDS. The primary outcome was the proportion of patients at risk of ARDS. Secondary outcomes included ventilatory management (including tidal volume [VT] expressed as mL/kg predicted bodyweight [PBW], and positive end-expiratory pressure [PEEP] expressed as cm H2O), development of pulmonary complications, and clinical outcomes. The PRoVENT study is registered at ClinicalTrials.gov, NCT01868321. The study has been completed. Findings Of 3023 patients screened for the study, 935 individuals fulfilled the inclusion criteria. Of these critically ill patients, 282 were at risk of ARDS (30%, 95% CI 27â33), representing 0·14 cases per ICU bed over a 1-week period. VTwas similar for patients at risk and not at risk of ARDS (median 7·6 mL/kg PBW [IQR 6·7â9·1] vs 7·9 mL/kg PBW [6·8â9·1]; p=0·346). PEEP was higher in patients at risk of ARDS compared with those not at risk (median 6·0 cm H2O [IQR 5·0â8·0] vs 5·0 cm H2O [5·0â7·0]; p<0·0001). The prevalence of ARDS in patients at risk of ARDS was higher than in individuals not at risk of ARDS (19/260 [7%] vs 17/556 [3%]; p=0·004). Compared with individuals not at risk of ARDS, patients at risk of ARDS had higher in-hospital mortality (86/543 [16%] vs 74/232 [32%]; p<0·0001), ICU mortality (62/533 [12%] vs 66/227 [29%]; p<0·0001), and 90-day mortality (109/653 [17%] vs 88/282 [31%]; p<0·0001). VTdid not differ between patients who did and did not develop ARDS (p=0·471 for those at risk of ARDS; p=0·323 for those not at risk). Interpretation Around a third of patients receiving mechanical ventilation in the ICU were at risk of ARDS. Pulmonary complications occur frequently in patients at risk of ARDS and their clinical outcome is worse compared with those not at risk of ARDS. There is potential for improvement in the management of patients without ARDS. Further refinements are needed for prediction of ARDS. Funding None