Hemodynamic effects of the inspiratory flow rate in patients with septic shock
© Current Science Ltd 2000
Published: 21 March 2000
The purpose of the study was to assess the effects of changes in inspiratory flow (IF) on hemodynamic parameters of mechanically-ventilated patients with septic shock.
Eight patients with septic shock (pneumonia n=2 and abdominal sepsis n=6) were included in the study. A pulmonary artery catheter with continuous SvO2 and CO display had been inserted to titrate fluid and vasopressor therapy. The patients were on volume control ventilation with a square flow waveform. Three different levels of IF were applied, each for a period of thirty min (IF1=40 l/min, IF2=50 l/min, IF3=60 l/min). At the end of each period the following parameters were recorded: CVP, PCWP, MAP, MPAP, CI, SVRI, PVRI,LVSWI, RVSWI, SaO2, SvO2, DO2. The paired t-testmethod was used to compare the results at the three different levels of IF.
Two patients were withdrawn from the study, due to necessary manipulation in the infusion rate of fluids and/or vasopressors. In six patients, a significant increase in LVSWI from IF1 to IF3 (5.22± 1.38 gm/m2 [mean ± SE], P=0.013) was observed. No further significant differences were recognized.
The change in the IF from 40 to 60 l/min did not have any negative effect in the hemodynamic profile of patients with septic shock. On the contrary, it led to an increase of the LVSWI.