The Kitchen Sink: Mortality Assessment of Salvage Therapies in Refractory Shock
Objective: The management of refractory shock remains a challenge with nearly ubiquitous mortality requiring novel therapies to maintain hemodynamics when conventional mechanisms fail. Several exploratory therapies display potential efficacy in the literature, but it remains unclear which therapy is superior. We aim to clarify the efficacy of the current salvage therapies: Angiotensin II (ATII) vs Methylene Blue (MB) vs Vitamin C with thiamine and hydrocortisone (VC) for refractory shock. We hypothesize that these therapies will improve survivability and decrease other vasopressors in patients with refractory shock.
Design: Retrospective chart review.
Setting: Single center mixed intensive care unit (ICU).
Patients: Adult patients admitted to the ICU with refractory shock between January 2015 through September 2018.
Interventions: Initiation of ATII, MB, and/or VC.
Measurements: The primary outcome was in hospital mortality. Secondary outcomes included: change in dosage of standard vasopressors after initiation of salvage therapy, incidence of acute renal failure (ARF) with need for renal replacement therapy (RRT), and ICU length of stay.
Results: As monotherapy, those that received ATII (34 patients), mortality was seen in 85.3%, for MB, 77.8%, and for Vit C, 51.9%. After adjusting for severity of illness, those who received ATII alone as compared to VC had a significant higher mortality (aOR=3.45; 95% CI=confidence interval: 1.08–10.99; P=0.036) vs (OR=0.36; 95% CI: 0.19–0.67; p=0.001), respectively. No statistical difference was seen in norepinephrine equivalents after initiation of salvage therapy. ATII groups did have a significantly higher incidence of RRT.
Conclusion: While these therapies have shown improvement in hemodynamics in recent literature, this study questions the impact on overall mortality. This could be due to the baseline low survivability in this patient population and not initiating these rescue therapies soon enough. More prospective studies are needed to further clarify their potential role in refractory shock.