Epidemiology of secondary fluid bolus therapy for infection-associated hypotension

Fluid bolus therapy (FBT) is a common therapy for hypotensive sepsis, but no studies have compared primary FBT (in the first 6 hours after presentation to the emergency department [ED]) with secondary FBT (6-24 hours after presentation to the ED). We aimed to describe the patterns of use, physiological sequelae and outcomes of patients with hypotensive sepsis who were treated with primary FBT or combined primary and secondary FBT (secondary FBT).

A retrospective observational study of patients with hypotensive sepsis presenting to the ED of a tertiary hospital from 1 January to 31 December 2010.

We studied 100 consecutive eligible patients (primary FBT, n = 52; secondary FBT, n = 48). Secondary FBT occurred in the ward (n = 31) or in the intensive care unit (n = 17). More patients receiving secondary FBT had sepsis with undefined focus or septic shock (P = 0.005, P = 0.0001, respectively), and fewer patients receiving secondary FBT had pneumonia (P = 0.0004). At 24 hours, the use of secondary FBT was similar for patients admitted to the ward and the ICU, and represented about 40% of all secondary fluids given. The volume of any bolus was greater during primary resuscitation, and the size of physiological changes associated with FBT diminished with time. The mortality rate at 28 days was 27%, and was similar for ward and ICU admissions.

Secondary FBT is given to about half of patients presenting with hypotensive sepsis, takes place in wards more often than in the ICU and delivers a significant proportion of overall fluids, but is associated with limited changes in measured physiological variables.