Interaction between fluids and vasoactive agents on mortality in septic shock: a multicenter, observational study

Area of Science:

• Critical Care Medicine
• Emergency Medicine
• Pharmacology

Background:

• Septic shock management involves fluids and vasoactive agents, but their optimal combined administration is unclear.
• Understanding treatment interactions is crucial for improving patient outcomes in septic shock.

Purpose of the Study:

• To investigate the association between combined fluid and vasoactive agent administration and hospital mortality in septic shock.
• To determine the optimal timing and volume of fluid resuscitation and vasoactive agent initiation.

Main Methods:

• Retrospective analysis of 2,849 patients with septic shock from 24 hospitals across 3 countries.
• Multivariable logistic regression was used to assess the impact of fluid volumes and vasoactive agent timing on hospital mortality.
• Analysis included interactions between fluid administration and vasoactive agent initiation, adjusting for confounders.

Main Results:

• A significant interaction between fluid administration and vasoactive agent use was observed (p < 0.0001).
• Lowest mortality rates were linked to initiating vasoactive agents 1-6 hours after shock onset, coupled with substantial fluid resuscitation ( >1 L in the first hour, >2.4 L from 1-6 hours, and 1.6-3.5 L from 6-24 hours).
• Early initiation of vasoactive agents within the first hour was associated with higher mortality, partly due to reduced fluid administration.

Conclusions:

• The initial hour of septic shock resuscitation should prioritize aggressive intravenous fluid administration.
• Vasoactive agents should be introduced after the first hour, with continued aggressive fluid resuscitation.
• Early administration of vasoactive agents in the first hour may be detrimental and is not solely explained by concurrent fluid management.