Clinical Controversy Over Vasopressin in Septic Shock: A Survey of Critical Care Pharmacists

Timing of Vasopressin Addition to Norepinephrine and Efficacy Outcomes in Patients With Septic Shock

BACKGROUND

Current guidelines recommend norepinephrine as the first-line vasopressor in septic shock followed by addition of vasopressin to achieve a goal mean arterial pressure. Limited evidence exists evaluating how the timing of vasopressin addition affects clinical outcomes in septic shock.

OBJECTIVE

The objective of this study was to determine whether the timing of the addition of vasopressin to norepinephrine affects shock resolution.

METHODS

This was a multi-site, single system, retrospective cohort, institutional review board (IRB)-approved study examining adult patients with septic shock who received norepinephrine and vasopressin. Patients were divided and statistically analyzed in two subgroups: early vasopressin addition (<3 hours) and late vasopressin addition (≥3 hours). The primary outcome was time to shock resolution, defined as vasopressor free for at least 24 hours. Secondary outcomes included norepinephrine dose at 3 hours after initiation of vasopressin, in-hospital mortality, and intensive care unit length of stay.

RESULTS

A total of 243 patients were included in this study. A statistically significant decrease in time to shock resolution was observed in the early vasopressin addition group compared to the late vasopressin addition group (37.6 hours vs 60.7 hours; adjusted hazard ratio [HR]: 2.07 [1.48-2.89; P = <0.001]). The early addition of vasopressin did not affect norepinephrine dose or in-hospital mortality but did lead to a decreased intensive care unit (ICU) length of stay (4.3 days vs 5.3 days, P = 0.02).

CONCLUSION AND RELEVANCE

Addition of vasopressin to norepinephrine within 3 hours was associated with a faster time to shock resolution. These findings suggest a potential for improved clinical outcomes with earlier vasopressin addition.

Vasopressor Discontinuation Order in Septic Shock With Reduced Left Ventricular Function

BACKGROUND

The optimal vasopressor management for septic patients with left ventricular (LV) dysfunction has not been well established, and current evidence is conflicting regarding the optimal vasopressor discontinuation order.

OBJECTIVE

The objective was to evaluate the impact of LV dysfunction on the hemodynamic management of septic shock by assessing the incidence of clinically significant hypotension after vasopressor discontinuation.

METHODS

In this single-center, retrospective cohort study, adult patients were included if they met the Sepsis-3 definition of septic shock, had LV dysfunction (defined as an ejection fraction ≤40%), and received norepinephrine and vasopressin as the last vasopressors discontinued. The primary outcome was the incidence of clinically significant hypotension following discontinuation of vasopressin or norepinephrine. Clinically significant hypotension was defined as a MAP less than 60 mmHg and the need for either: 1) the reinstitution of the previously discontinued agent at any dosage, 2) the receipt of at least 500 mL of a crystalloid at a rate of at least 500 mL/hour, 3) or the receipt of at least 25 grams of albumin 5% at a rate of at least 25 gram/hour. Secondary outcomes included intensive care unit (ICU) and hospital lengths of stay, and ICU and hospital mortality.

RESULTS

A total of 78 patients met inclusion criteria, with 37 patients having vasopressin discontinued first and 41 having norepinephrine discontinued first. Clinically significant hypotension occurred in 28 patients (76%) following the discontinuation of vasopressin, compared to 28 patients (81%) following the discontinuation of norepinephrine (p = 0.61). ICU length of stay was 9 days in the vasopressin discontinued first cohort, compared to 15 days in the norepinephrine discontinued first cohort (p = 0.01). There was no statistically significant difference in mortality observed.

CONCLUSION

The discontinuation order of norepinephrine and vasopressin did not impact the incidence of clinically significant hypotension in patients with septic shock and LV dysfunction, but may influence ICU length of stay, although other factors may have impacted this finding.