A national shortage of norepinephrine in the United States was associated with higher rates of mortality among patients hospitalized with septic shock, investigators reported.

Rates of in-hospital mortality in 2011 were 40% during quarters when hospitals were facing shortages and 36% when they were not, Emily Vail, MD, and her associates said at the International Symposium on Intensive Care and Emergency Medicine. The report was published simultaneously in JAMA.

The link between norepinephrine shortage and death from septic shock persisted even after the researchers accounted for numerous clinical and demographic factors (adjusted odds ratio, 1.2; 95% confidence interval, 1.01 to 1.30; P = .03), wrote Dr. Vail of Columbia University, New York (JAMA. 2017 Mar 21. doi: 10.1001/jama.2017.2841 ).

Drug shortages are common in the United States, but few studies have explored their effects on patient outcomes. Investigators compared mortality rates among affected patients during 3-month intervals when hospitals were and were not using at least 20% less norepinephrine than baseline. The researchers used Premier Healthcare Database, which includes both standard claims and detailed, dated logs of all services billed to patients or insurance, with minimal missing data.

A total of 77% patients admitted with septic shock received norepinephrine before the shortage. During the lowest point of the shortage, 56% of patients received it, the researchers reported. Clinicians most often used phenylephrine instead, prescribing it to up to 54% of patients during the worst time of the shortage. The absolute increase in mortality during the quarters of shortage was 3.7% (95% CI, 1.5%-6.0%).

Several factors might explain the link between norepinephrine shortage and mortality, said the investigators. The vasopressors chosen to replace norepinephrine might result directly in worse outcomes, but a decrease in norepinephrine use also might be a proxy for relevant variables such as delayed use of vasopressors, lack of knowledge of how to optimally dose vasopressors besides norepinephrine, or the absence of a pharmacist dedicated to helping optimize the use of limited supplies.

The study did not uncover a dose-response association between greater decreases in norepinephrine use and increased mortality, the researchers noted. “This may be due to a threshold effect of vasopressor shortage on mortality, or lack of power due to relatively few hospital quarters at the extreme levels of vasopressor shortage,” they wrote.

Because the deaths captured included only those that occurred in-hospital, “the results may have underestimated mortality, particularly for hospitals that tend transfer patients early to other skilled care facilities,” the researchers noted.

The cohort of patients was limited to those who received vasopressors for 2 or more days and excluded patients who died on the first day of vasopressor treatment, the researchers said.

The Herbert and Florence Irving Scholars Program at Columbia University provided funding. One coinvestigator disclosed grant funding from the National Institutes of Health and personal fees from UpToDate. The other investigators reported having no conflicts of interest.