Objective: To compare the sedative effects of propofol and midazolam, or combination of them on emergency critically ill patients on mechanical ventilation.
Methods: Medical records of 68 patients treated in emergency intensive care unit (EICU) receiving mechanical ventilation and sedation care from August 2007 to July 2011 were reviewed retrospectively. According to the type of sedatives used, patients were assigned to propofol group (n=28), midazolam group (n=20), combination of propofol and midazolam group (combination group, n=20). Patients in the former two groups were given a loading dose of propofol or midazolam and followed by continuous infusion of the same drugs. Those in the combination group were given a loading dose of propofol and followed by continuous infusion of propofol together with midazolam. In this study, Ramsay anesthesia score was used to evaluate the effectiveness of sedation. The patients in three groups were maintained at depth of sedation level 2-4 according to the Ramsay score, and reassessed every 1-2 hours after the initiation. The change in vital signs and respirator related parameters were observed before and after administration in three groups, and the treatment information of sedative and mechanical ventilation were recorded.
Results: Heart rate (HR), respiratory rate (RR), systolic blood pressure (SBP), diastolic blood pressure (DBP), tidal volume (VT) were decreased at 1 hour after treatment compared with those before treatment in all the three groups, while the blood oxygen saturation (SpO₂) was increased. There were no significant differences in RR and SpO₂ at 1 hour after treatment among three groups. HR, SBP, DBP at 1 hour after treatment in propofol group were significantly decreased compared with those in midazolam group and combination group (HR: 20.43 ± 13.52 bpm vs. 15.27 ± 13.71 bpm, 18.54 ± 10.07 bpm; SBP: 39.26 ± 16.64 mm Hg vs. 25.80 ± 21.09 mm Hg, 31.50 ± 28.20 mm Hg; DBP: 21.35 ± 12.91 mm Hg vs. 14.07 ± 10.53 mm Hg, 16.42 ± 13.55 mm Hg, P<0.05 or P<0.01). VT at 1 hour after beginning of the treatment in combination group was decreased significantly compared with propofol group and midazolam group (121.06 ± 96.50 ml vs. 33.36 ± 28.49 ml, 39.94 ± 33.24 ml, both P<0.01). The drug dosage in combination group was decreased significantly compared with propofol group and midazolam group (total dosage of propofol: 25.21 ± 15.33 mg/kg vs. 90.83 ± 17.42 mg/kg, total dosage of midazolam: 2.37 ± 1.87 mg/kg vs. 4.02 ± 3.62 mg/kg, both P<0.01), but there was no significant difference in sedation time among groups. EICU stay days in combination group was shortened significantly compared with propofol group and midazolam group (7.75 ± 5.20 days vs. 12.53 ± 8.24 days, 15.20 ± 8.33 days, both P<0.05), but there was no significant difference in mechanical ventilation duration among groups.
Conclusions: A combination of propofol with midazolam for emergency critically ill patients on mechanical ventilation not only can achieve a good sedative effect, reduce total amount of the drug, but also alleviate the inhibitory effect of propofol on the circulation, improve the symptoms of asynchronous ventilation, and reduce stay time in EICU.