Is Nocturnal Extubation After Cardiac Surgery Associated with Worse Outcomes?

Abstract

Background: There is an increased risk of medical errors overnight compared with the day, secondary to fatigue, paucity of resources, and decreased staffing. Whether this increased risk extends to liberation from mechanical ventilation is controversial. We evaluated the relationship between length of intubation and differences between diurnal and nocturnal extubation. Methods: We studied patients who had cardiac surgical procedures between January 1, 2007, and March 31, 2016, who were intubated on arrival to the cardiovascular intensive care unit (ICU) immediately after operation. Patients were divided into those extubated 24 or fewer hours or more than 24 hours after ICU arrival and were further divided by time of extubation: daytime (7 AM to 7 PM) and nocturnal (7 PM to 7 AM). We used multivariable logistic regression to determine whether nocturnal extubation was associated with increased mortality compared with diurnal extubation. Subgroup analyses investigated the effect of laboratory values, fluid management, and infused medicines. Results: Two hundred seventy-eight of 8,705 patients (3.2%) died in the hospital; 84 died without being extubated. Of the remaining 8,621 patients, 6,982 patients (81%) were extubated within 24 hours of arrival to the ICU. Eighty-three of the patients (1.1%) died, and the proportion did not vary between day and night. In the delayed extubation group, 127 of the 1,639 patients (7.7%) died. Nocturnal extubation was associated with increased mortality only in the patients extubated more than 24 hours after ICU admission (adjusted odds ratio 2.46, 95% confidence interval: 1.45 to 4.16, p = 0.001). This increased risk persisted through all subgroup and sensitivity analyses. Conclusions: Nocturnal extubation was associated with increased mortality only in the group of patients receiving more than 24 hours of mechanical ventilation.