(917) Angiotensin II Stewardship at a Community-Based Teaching Hospital

Introduction: Angiotensin II (AT II) is a potent vasoconstrictor that binds to AT II receptors on blood vessel walls and increases circulating angiotensin to increase mean arterial pressure in vasodilatory shock; however, studies of AT II for salvage therapy of septic shock have not shown patient-centered benefits. After having AT II available at our institution for 5 years, we implemented provider education and increased the maximum usual rate of norepinephrine (NE) to foster evidence-based vasopressor utilization. In this study, we analyzed AT II use and patient outcomes before and after these interventions, hypothesizing that utilization would decrease.

Methods: This single-center IRB-approved retrospective review was conducted at a community-based teaching hospital. We included adults who received AT II from 7/1-12/19/22 (pre-phase) and 8/1/23-3/30/24 (post-phase). Quality improvement initiatives were implemented in 6/23. Primary outcomes were AT II utilization and cost avoidance. Secondary outcomes included cumulative vasopressor dose at AT II initiation, shock duration, thromboembolism, and mortality. Outcomes were evaluated using descriptive statistics.

Results: 74 patients were included, with 43 receiving AT II in the pre-phase and 31 in the post-phase. Baseline patient characteristics were similar, although in the post-phase AT II was used more commonly in the surgical ICU (29% vs 12%) and operating room (19 vs 0%) and less often in the medical ICU (52% vs 88%). 98 AT II vials were used in the pre-phase as compared to 53 vials in the post-phase, resulting in a reduction in monthly utilization from 16.3 to 7.6 vials/month with an estimated annual cost avoidance of $170,295. There was no change in cumulative vasopressor dose at AT II initiation between the pre and post-groups (1.1 +/- 0.6 vs 1.1 +/- 0.8 mcg/kg/min, respectively) but NE dose at AT II initiation increased (0.4 +/- 0.1 vs 0.7 +/- 0.5 mcg/kg/min, respectively). Duration of shock (14.6 hr (IQR 4-49.4 hr) vs 15 hr (IQR 0.8-89 hr), rate of thromboembolism (5% vs 0%), and mortality (63% vs 70%) were similar in both groups.

Conclusions: At our institution, provider education and policy changes related to vasopressor utilization were associated with a 53% reduction in average monthly AT II utilization and an annual cost avoidance of $170,295.