Immediate effects of a bolus of furosemide on hemodynamics in critically ill patients

Purpose

To study the immediate effects of a bolus of furosemide on hemodynamics, in critically ill patients, before the appearance of a significant increase in diuresis.

Methods

A double-blind, placebo-controlled study in 34 critically ill patients; 28 of them with sepsis. All patients participating in the study had adequate diuresis (at least 0.5 ml/min) and none had received a diuretic in the past 8 hours. All patients randomly received either a bolus of 40 mg furosemide or 4 ml N/S (placebo). Eight hours later there was crossing over to the other branch of the study. The physician recording the changes in physiologic parameters was blinded as to the substance infused. We recorded CVP, systolic and diastolic blood pressure and diuresis per minute at t0 (the time of infusion), t1 (5 min from infusion) and t2 (15 min from infusion).

Results

In the intervention group, CVP at t0 was 11.35 ± 4.80 mmHg (mean ± SD) and there was no significant difference in CVP from t0 to t2 (paired t test). No significant difference was also observed in systolic and diastolic blood pressure and in heart rate. Although there was an increase in diuresis at t2 compared with t0, it did not reach statistical significance. Additionally, the observed changes at t1 and t2 in CVP, blood pressure and diuresis in the intervention group did not differ from changes observed in the placebo group.

Conclusion

Before an obvious effect on diuresis has become obvious, a bolus of furosemide has no immediate effect in CVP or blood pressure in critically ill patients. Furosemide has no immediate hemodynamic effects independent of its diuretic action.