Overnight extubations associated with higher rates of mortality

Patients with mechanical ventilation who undergo extubation overnight have increased rates of ICU and hospital mortality compared to those who undergo extubation during the daytime, according to data published in JAMA Internal Medicine.

“Mechanical ventilation for acute respiratory failure is frequent in U.S. ICUs. Mechanical ventilation is associated with significant morbidity — pneumonia, weakness, and delirium — that increases with [mechanical ventilation] duration,” Hayley B. Gershengorn, MD, of Albert Einstein College of Medicine and Montefiore Medical Center in Bronx, New York, and colleagues wrote. “Therefore, extubation as soon as patients are clinically ready may be beneficial, regardless of the time of day. [However], very little is known about the frequency, safety, or effectiveness of overnight extubations.”

Gershengorn and colleagues performed a retrospective study and used 2 and Mann-Whitney tests to determine the rate of nighttime extubations and to evaluate the relationship between overnight extubations and clinical outcomes such as ICU reintubation frequency, ICU and hospital mortality, and ICU and hospital length of stay.

In addition, the researchers used a multilevel multivariable regression model to detect the clinical features of overnight extubations. The model was grouped by each ICU.

The study cohort included 97,844 patients aged 18 years or older with a mean age of 58.3 years undergoing mechanical ventilation in 165 ICUs in the U.S. (40.8% men; 59.2% women). Participants were recruited from the Project IMPACT database from October 1, 2000, to March 29, 2009.

The researchers described overnight extubation as occurring between 7 p.m. and 6:59 a.m.

Patients undergoing overnight vs. daytime extubation were paired using a propensity score-matching strategy. Patients with mechanical ventilation duration of less than 12 and at least 12 hours were separated.

The researchers found that 20.1% of patients underwent overnight extubation during the study period, and the percentage decreased from 23.3% in 2000-2001 to 18.8% in 2009 (P = .001).

In a multivariable analysis, patients with a duration of mechanical ventilation of less than 12 hours were more likely to receive overnight extubation compared with those with duration of 12 hours to less than 1 day (adjusted odds ratio [AOR] = 0.2; 95% CI, 0.19-0.21); 1 to <2 days (AOR = 0.26; 95% CI, 0.24-0.280; 2 to <7 days (AOR = 0.22; 95% CI, 0.21-0.240; and 7 days or more (AOR = 0.24; 95% CI, 0.22-0.26).

Overall, there were 4,518 propensity-matched pairs with mechanical ventilation duration of less than 12 hours, and 5,761 pairs with mechanical ventilation duration of at least 12 hours. The reintubation rate for overnight extubation in patients with mechanical ventilation duration of less than 12 hours was 5.9%. Similarly, the reintubation rate for daytime was 5.6%. However, patients undergoing overnight extubation had an increased mortality rate (ICU, 5.6% vs. 4.6%, P = .03; hospital, 8.3% vs. 7.0%, P = .01).

Shorter ICU length of stay was observed for nighttime extubations compared with daytime (median [interquartile range], 1.1 [0.8-2.3] vs. 1.4 [0.9-2.5] days; P < .001), while hospital length of stay was similar regardless of the time of day extubation was performed (median [interquartile range], 7 [4-12] vs. 7 [3-12] days; P = .03).

Furthermore, greater reintubation rates in the ICU (14.6% vs. 12.4%; P < .001), as well as greater mortality rates in the ICU (11.2% vs 6.1%; P < .001) and in the hospital (16% vs 11.1%; P < .001) were seen in patients who underwent overnight extubation with mechanical ventilation duration of at least 12 hours vs. daytime. Differences in length of stay were not detected.

“Our finding that overnight extubation is associated with higher mortality is of great potential clinical import,” Gershengorn and colleagues concluded. “Although our study cannot prove causality, our findings raise serious concerns about the routine practice of overnight extubation for many patients in the ICU. We must be cautious as ICUs move to employ more high-level staff at night and push for standardization of care throughout all hours of the day. Further studies are needed to understand why overnight extubation results in poorer outcomes.”

In an accompanying editorial, Peter K. Moore, MD, and Michael A. Matthay, MD, both of the department of medicine at University of California, San Francisco, note the importance of identifying the possible risks of overnight extubations to enhance the care of patients with mechanical ventilation.

“Although propensity matching and sensitivity analyses strengthen the associations in this study, they are imperfect statistical methods that cannot completely eliminate bias and confounding,” they wrote. “Future prospective studies should be undertaken to confirm these findings, to assess for underlying mechanisms, and to elucidate which patient populations are most likely to benefit from or be harmed by extubation at night. The risk factors for extubation failure have been described and emphasize that extubation failure can worsen clinical outcomes independent of the underlying severity of illness.” – by Alaina Tedesco

Disclosure: Gershengorn reports no relevant financial disclosures. Please see the full studies for a complete list of all other authors’ disclosures.