Cardiopulmonary effects of Intralipid infusion in critically ill patients.

Cardiopulmonary effects of 500 ml of 20% iv fat emulsion (Intralipid) infusion in two groups of patients who required mechanical ventilation were evaluated in our Critical Care Center. Group 1 included ten patients void of signs or symptoms of sepsis. Group 2 consisted of ten patients exhibiting clinical and laboratory signs and symptoms of sepsis. Data were measured before and immediately after Intralipid infusion and when serum lipemia cleared. Intralipid infusion precipitated a significant increase in venous admixture (Qsp/Qt) from 13.7 +/- 3.6 (SEM) to 18.0 +/- 6.5% and from 22.0 +/- 4.8 to 25.8 +/- 7.0% in groups 1 and 2, respectively. Mean pulmonary artery pressure (MPAP) increased from 22.7 +/- 4.2 to 29.2 +/- 8.1 mm Hg and 26.4 +/- 6.8 to 28.0 +/- 4.0 mm Hg in groups 1 and 2, respectively. When serum lipemia cleared, Qsp/Qt and MPAP returned to preinfusion levels. We conclude that Intralipid infusion increases pulmonary artery pressure and venous admixture in critically ill patients. These changes are temporary and coincidental with serum lipemia rather than presence or absence of sepsis. Adequate levels of oxygenation should be confirmed during Intralipid infusion in patients with borderline oxygenation.