[Comparative hemodynamic effects of midazolam and flunitrazepam in head injury patients under controlled ventilation]

The haemodynamic effects of midazolam were compared with those of flunitrazepam in 10 patients with severe head injury under controlled ventilation. Right atrial pressure, pulmonary pressure, pulmonary capillary wedge pressure and cardiac output were measured using a Swan-Ganz thermodilution catheter. Arterial pressure (Pa) was recorded by radial arterial canulation. All patients in this cross-over study received midazolam (0.15 mg X kg-1) and flunitrazepam (0.02 mg X kg-1) intravenously randomly, with 24 h between the two injections. The measurements were first carried out before and then 5, 10, 20, 30 and 60 min after injection. The only significant variations after midazolam and flunitrazepam were a fall in Pa (from 93 +/- 12 to 81 +/- 11 mmHg for midazolam and from 89 +/- 14 to 78 +/- 20 mmHg for flunitrazepam) and in cardiac index (from 4.80 +/- 1.03 to 4.17 +/- 1.14 l X min-1 X m-2 for midazolam and from 5.18 +/- 1.32 to 4.54 +/- 1.03 l X min-1 X m-2 for flunitrazepam). The small decrease in heart rate was not significant. The cardiovascular changes after midazolam and flunitrazepam were small and similar for both drugs. It seemed that midazolam and flunitrazepam were safe for sedating head injured patients under controlled ventilation.