(1474) Analysis of the Safety and Associated Costs Among Vasopressin Discontinuation Strategies

Introduction: Vasopressin (AVP) is used to augment mean arterial pressure (MAP) in patients receiving norepinephrine (NE) in vasodilatory shock. AVP has a longer half-life than NE, which could be advantageous when weaning the medication. A previous initiative at our institution suggested that AVP could be stopped when a NE dose is ≥5 mcg/min, but the safety of this strategy has not been evaluated. This study’s purpose was to compare 3 distinct vasopressor discontinuation strategies

Methods: This retrospective study included adults receiving AVP as an adjunct agent to NE in the setting of shock. Subjects were excluded if they transferred from another facility, died during vasopressor therapy, or if AVP and NE were not the last two vasopressors stopped. The primary outcome was the difference in hemodynamic compromise within 6 hours after initial vasopressor discontinuation among three groups: 1.) NE discontinued first, 2.) Early AVP discontinuation (NE dose ≥5 mcg/min), and 3.) Late AVP discontinuation (NE dose < 5 mcg/min). Secondary outcomes included hemodynamic compromise at 12 and 24 hours, intensive care unit (ICU) and hospital length of stay (LOS), death, arrhythmias, and costs.

Results: The study included 158 subjects which were 58% male with a mean age of 56. Aside from the cohorts’ baseline MAP values (NE 58.5mmHg vs. Early AVP 64mmHg vs. Late AVP 59mmHg, p=0.04), baseline characteristics were similar among the groups. Hemodynamic compromise at 6 hours was similar among the groups (NE 94.8% vs. Early AVP 90.2% vs. Late AVP 91.5%, p=0.66). A higher incidence of vasopressor re-initiation occurred when NE was stopped first compared to the Early and Late AVP discontinuation strategies (34.5% vs. 9.8% vs. 6.8%, p< 0.001), whereas the Early AVP group required more fluid boluses compared to the NE first or Late AVP discontinuation strategies (36.6% vs. 15.5% vs. 13.6%, p=0.01). The Early AVP discontinuation saved 1 bag of AVP per case compared to the NE or Late AVP strategies. No differences in MAP, mortality, or LOS were observed among the cohorts.

Conclusions: In the setting of shock, an Early AVP discontinuation strategy did not cause any more hemodynamic compromise than a NE first or Late AVP discontinuation strategy. Further studies are needed to validate this strategy.