The effects of night-time surgery on patient outcome

The effects of night-time surgery on patient outcome

  • issue 81

Andrea Cortegiani, Giulia Ingoglia, Mariachiara Ippolito

Over the past 50 years, increasing attention has been given to patient safety; nevertheless, perioperative complications are still leading to roughly more than 1.5 million deaths on an annual basis.1 During the perioperative care, clinical outcomes originate from a complex interaction between patients’ condition, technical aspects (e.g. expertise of the team), intrinsic characteristics of the environment (e.g. equipment availability, quality of postoperative care etc.) and the so-called ‘human factor’. Furthermore, the human factor comprises at least an individual level, a team level and an organisational level and seems reasonably involved in 82% of anaesthesia incidents.2 Thus, the aetiology of an adverse event is multifactorial.

Fatigue, defined as ‘the subjective feeling of the need to sleep, and increased physiological drive to fall asleep and a state of decreased alertness’, has been considered as a component of the human factor, and its role in decreasing clinicians’ performance has been studied.3,4,5,6,7

Sleep deprivation is known to cause deterioration of cognitive and psychomotor skills.8 Moreover, night surgery requires team alertness during a period of sleep tendency or sleep inertia, potentially causing decreased performance. A survey conducted on 301 anaesthetists found 86% of respondents had made at least an error in clinical management because of fatigue and 32% of respondents recalled a fatigue-related error in the previous six months.9 In a more recent survey, 91% of UK consultants have reported work-related fatigue.10 Surgeons also have recognised fatigue and work-load as causes of surgical errors in 33% of the cases.11

Recently, the Association of Anaesthetists of Great Britain and Ireland (AAGBI) and the Royal College of Anaesthetists (RcoA) have launched the campaign ‘Fight fatigue’ to increase general awareness towards the phenomenon and to suggest organisational and individual measures to reduce risks for both patients and physicians.12 The project included the creation of the checklist ‘I’M SAFE’, a useful tool for self-assessment of physicians’ fitness to work before a night shift or task. In the case of negative evaluation, the anaesthetist is expected to call for help, but still, organisational concerns can reduce the efficacy and the external validity of this tool.13

Despite the risks, healthcare workers are often pushed to care about productivity and to apply the so-called ‘ETTO Principle’, a trade-off between efficiency and thoroughness.14 The need to reduce day-time overcrowding of operating rooms, for example, can be one of the reasons for night-time/after-hour scheduling of elective surgeries, despite it has been recommended that only life and limb-threatening operations should be performed at night.15

The evidence regarding the effect of night/after-hour surgery on patient outcome is large but conflicting. In 2015, Van Zaane et al. performed an analysis of data from the EUSOS study,16 with more than eleven thousand patients, to assess the association between non-elective non-cardiac surgery at night and in-hospital mortality.17 In this analysis, in-hospital mortality was shown to increase sequentially from day time to evening [OR 1.14; 95% CI 0.94 to 1.38] to night time [OR 1.62; 95% CI 1.22 to 2.14], with a peak incidence of 19.1% and an OR of 6.37 (95% CI 2.72 to 14.95) between 4:00 and 4:59. Patients who underwent urgently or emergency surgery during the night also resulted to have a higher probability of being admitted to a critical care unit. In the adjusted analysis, conducted for factors associated with mortality, neither evening nor night-time surgery remained significantly associated with in-hospital mortality. The authors suggested for larger and prospective studies, highlighting that the risk of over-fitting exists and that the study was underpowered to detect a marginal increase in risk-adjusted mortality.

More recently, Cortegiani et al. conducted a post-hoc analysis of the large cohort LAS-VEGAS study18to evaluate the association between night-time surgery and intraoperative adverse events and postoperative pulmonary complications.19 Their results have pointed out an association between intraoperative adverse events and postoperative pulmonary complications and night-time surgery. Although postoperative pulmonary complications could be determined by worse patients’ conditions, higher risk types of surgery and by differences in intraoperative management at night-time, the higher incidence of adverse events remained independently associated with night-time surgeries, even after correction for potentially confounding factors. Of note, 74% of patients in the night-time group underwent elective surgery. The authors themselves discussed the lack of data on the level of training, year of training, and experience of anaesthesiologists and surgeons and called for further studies.

Evidence on the topic is low and based on observational studies. More evidence is needed for institutions to take into account the risk related tonight/after-hour surgery. Moreover, a deeper understanding of the associated risk could help to find measures to counterbalance these risks for the cases of surgery that cannot be delayed until daytime. Randomised controlled trials about this topic are unfeasible for ethical concerns, but larger and prospective designed studies are possible. It would be important to take into account reasonable confounders, with particular attention to human factors.

At Euroanesthesia 2020, data from a systematic review and meta-analysis performed on 40 observational studies with approximatively 3 million patients included will be presented and discussed.20



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  20. Cortegiani A, Misseri G, Einav S et al. Effect of nighttime surgery on mortality and adverse events: a systematic review and meta-analysis. PROSPERO 2019 CRD42019128534 Available from: