Introduction: No data compare the dynamics of PVE after crystalloid infusion before and after sepsis. Stahle et al1 have developed pharmacokinetic models to describe PVE in response to fluid infusion. We hypothesized that the septic state decreases PVE after 0.9 % saline infusion. Methods: Adult (n=6) female merino sheep (42±5 kg) were splenectomized and chronically instrumented with cardiovascular catheters. After a 5-day recovery period, animals were subjected to a 3-day test period. On day 1 (baseline) we infused 25 mL/kg of 0.9% saline for 20 min. On day 2 we initiated a continuous Pseudomonas aeruginosa infusion. Four hrs thereafter (early sepsis), and 24 hrs thereafter (late sepsis) we infused 25 mL/kg of 0.9% saline for 20 min. PVE was analyzed kinetically from decreases in Hemoglobin and initial plasma volumes measured using Evan's blue dye. Data were compared via repeated measures analysis of variance, with P<0.05 considered significant. Results: One sheep died during late sepsis. Plasma oncotic pressure decreased from 20.9±1.9 (baseline) to 17.3±0.7 (early) and to 13.9±1.6 mmHg (late sepsis). Systemic vascular resistance decreased from 1729±181 (baseline) to 1371±181 (early) and 1098±236 dyne sec cm-6 (late sepsis). Cardiac index increased from 5.1±0.7 (baseline) to 5.9±0.8 (early) and 7.8±1.6 L/min/m2 (late sepsis). PVE was 312± 87 mL, 386±64 mL and 400±88 mL for baseline, early and late sepsis, respectively, at the end of infusion and then decreased over 30 to 40 min to 97±30 mL, 151±72 mL and 103±82 mL, respectively. Urinary output and calculated extravascular fluid accumulation were not different among groups. Conclusion: Changed hemodynamics in the septic state do not change PVE in response to a crystalloid volume challenge.
ASJC Scopus subject areas
- Critical Care and Intensive Care Medicine