A. CortegianiC. GregorettiA. S. NetoS. N.T. HemmesL. BallJ. CanetM. HiesmayrM. W. HollmannG. H. MillsM. F.V. MeloC. PutensenW. SchmidP. SevergniniH. WriggeM. Gama de AbreuM. J. SchultzP. PelosiW. KroellH. MetzlerG. StruberT. WegscheiderH. GombotzB. UrbanekD. KahnM. MomeniA. PospiechF. LoisP. ForgetI. GrosuJ. PoelaertV. MosseveldeM. C. van MalderenD. DylstJ. V. MelkebeekM. BeranS. D. HertL. D. BaerdemaekerB. HeyseJ. V. LimmenP. WyffelsT. JacobsN. RoelsA. D. BruyneS. V.D. VeldeJ. Z. MarinaD. O. DejanaS. PernarJ. ZunicP. MiskovicA. ZilicS. KvolikD. IvicA. V. DarijaS. SkiljicH. VinkovicI. OputricK. JuricicV. FrkovicJ. KopicI. MirkovicJ. P. SaricG. ErcegM. B. DvorscakM. S. BrankaA. M. PavicicT. GoranovicB. MaldiniT. RadocajZ. GavranovicM. B. IngaM. SehovicP. StouracH. HarazimO. SmekalovaM. KosinovaT. KolacekK. HudacekM. DrabJ. BrujevicK. VitkovaK. JirmanovaI. VolfovaP. DzurnakovaK. LiskovaR. DudasR. FilipskyS. E. KafrawyH. H. AbdelwahabT. MetwallyA. R. AhmedE. S. Ahmed MostafaW. F. HasanA. G. AhmedH. YassinM. MagdyM. AbdelhadyM. MahranE. HerodesP. KivikJ. OganjanOspedale Policlinico San MartinoKBC OsijekKlinički Bolnički CentarUniversitair Ziekenhuis BrusselGeneral Hospital KarlovacDr. Josip Bencevic General HospitalUniversity Hospital in OstravaZiekenhuis Oost-LimburgUniversity Hospital of GhentUniversitäts-Klinikum Bonn und Medizinische FakultätMassachusetts General HospitalHospital Universitari Germans Trias i PujolFayoum UniversityDresden University Faculty of Medicine and University Hospital Carl Gustav CarusUniversità degli Studi di GenovaFakultni Nemocnice BrnoFaculty Hospital at Hradec KraloveUniversità degli Studi di PalermoHospital Israelita Albert EinsteinCliniques Universitaires Saint-LucMahidol UniversityMedizinische Universitat WienCairo UniversityUniversität LeipzigUniversity of Zagreb School of MedicineUniversità degli Studi dell'InsubriaLKH-Universitätsklinikum GrazUniversiteit van AmsterdamUniversity of SheffieldSuis medical Insurance HospitalLaboratorio Centralizzato Policlinico "P.Giaccone"Beni Sueif University HospitalNorth Estonia Medical CenterAZ Maria MiddelaresNemocnice ZnojmoAKH LinzGeneral Hospital ČakovecEl Sahel Teaching Hospital2020-01-272020-01-272019-03-01British Journal of Anaesthesia. Vol.122, No.3 (2019), 361-36914716771000709122-s2.0-85058784675https://repository.li.mahidol.ac.th/handle/20.500.14594/51853© 2018 British Journal of Anaesthesia 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.Mahidol UniversityMedicineArticleSCOPUS10.1016/j.bja.2018.10.063