SMALL HEMODYNAMIC-EFFECT OF TYPICAL RAPID VOLUME INFUSIONS IN CRITICALLY ILL PATIENTS

Objectives: To determine what volumes are commonly used for rapid volu me infusions in critically ill patients admitted to the intensive care unit (ICU) for >12 hrs; and to determine the effective ness of a typi cal rapid volume infusion in producing hemodynamic change and increasi ng left ventricular end-diastolic volume. Design: A prospective survey of clinical practice (part I)and a prospective clinical investigation (part 2). Setting: Two hospital ICUs (11 and six beds) of which one i s university affiliated. Patients: Critically ill patients admitted to the ICU for >12 hrs. Interventions: Infusion of 500 mL of normal sali ne over 5 to 10 mins. Measurements and Main Results: For 1 month, we r ecorded the volume and composition of all volume infusions given as a rapid bolus in patients admitted to the ICU for >12 hrs. We then measu red the effect of the median rapid volume infusion in a subset of 13 p atients by measuring hemodynamics (using arterial and pulmonary artery flotation catheters) and left ventricular end-diastolic area (using t ransgastric short-axis views from transesophageal echocardiograms). Du ring 470 patient days, 159 rapid volume infusions were administered. T he average rapid volume infusion administered was 390 +/- 160 mL (medi an 500; interquartile range 250 to 500). Crystalloid solutions were us ed for two thirds of the rapid volume infusions and colloid solutions were used for one third of the rapid volume infusions. The rapid volum e infusion of 500 mt of saline did not significantly increase mean art erial pressure (78.0 +/- 11.9 to 79.3 +/- 14.6 mm Hg), cardiac index ( 4.3 +/- 1.7 to 4.6 +/- 1.8 L/min/m(2)), right atrial pressure (11.1 +/ - 3.8 to 12.4 +/- 3.3 mm Hg), left ventricular end diastolic area (8.6 +/- 1.7 to 9.1 +/- 1.8 cm(2)/m(2)), or left ventricular end-systolic area (3.5 +/- 1.5 to 3.6 +/- 1.5 cm(2)/m(2)). Pulmonary artery occlusi on pressure increased slightly but significantly from 12.9 +/- 3.4 to 14.7 +/- 3.3 mm Hg (p < .05). Conclusions: After patients are admitted to the ICU for >12 hrs, rapid volume infusions are common therapeutic interventions but the rapid volume infusions are typically small. The effect of a typical rapid volume infusion on hemodynamics and left ve ntricular areas in these patients is surprisingly small.