Phenylephrine use ups mortality risk in septic shock patients

Septic shock patients, particularly those with ongoing tachycardia, who are treated with phenylephrine appears to be at greater risk of mortality, suggests a study.

A team of investigators performed a retrospective chart review from September 2015 to September 2017 to assess adult patients admitted to an intensive care unit (ICU) on vasopressors for management of septic shock. They divided patients into those treated with and without phenylephrine.

Mortality was the primary outcome, while days on vasopressors and ICU length of stay were secondary objectives. The investigators also performed two subgroup analyses: one for phenylephrine as first-line therapy and another for patients with tachycardia at initiation of vasopressors. Patients initiated on phenylephrine for salvage therapy were excluded.

A total of 499 patients were included in the analysis, of whom 148 (32 percent) were enrolled in the phenylephrine group.

Mortality rates were higher among patients treated with phenylephrine (56 percent vs 41 percent; p=0.003). No significant difference was noted in the days on vasopressors or ICU length of stay.

Notably, patients with ongoing tachycardia appeared to have greater mortality with phenylephrine (54 percent vs 36 percent; p=0.02). No difference was seen in mortality when phenylephrine was started as the initial vasopressor.

“Phenylephrine is a selective α₁-receptor agonist used to manage shock,” the investigators said.

“Current guidelines for septic shock recommend limited utilization of phenylephrine due to the lack of evidence available. This deviates from previous guidelines, which had recommendations of when utilization may be appropriate,” they noted.