Cardiovascular effects of intravenous midazolam after open heart surgery.
Midazolam is the sedating agent of choice in many paediatric intensive care units, and is usually administered as a continuous intravenous infusion with or without a preceding bolus dose. Ten haemodynamically stable children, ventilated in the early postoperative period after cardiac surgery and receiving intravenous morphine infusions, were given an intravenous bolus followed by a continuous infusion of midazolam. Haemodynamic data were recorded before the bolus, and 15 minutes and one hour later. A bolus of midazolam lowered the cardiac output by 24.1%. Arterial blood pressure, oxygen consumption, and mixed venous oxygen content fell significantly. There was a tendency for all variables subsequently to recover towards baseline values, within one hour, during a continuous infusion. An intravenous bolus of midazolam causes a transient but unwanted fall in cardiac output. It is suggested that in children who are receiving intravenous opiates, its use in the early postoperative period be limited to a continuous infusion.
Shekerdemian
L
L
Department of Paediatric Cardiology, Royal Brompton Hospital/National Heart and Lung Institute (Imperial College of Science, Technology and Medicine), London.
Bush
A
A
Redington
A
A
D000293:Adolescent; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D006348:Cardiac Surgical Procedures; D002648:Child; D002675:Child, Preschool; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D007223:Infant; D007231:Infant, Newborn; D008874:Midazolam / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D010101:Oxygen Consumption / Q000187:drug effects; D011182:Postoperative Care; D011446:Prospective Studies; D014655:Vascular Resistance / Q000187:drug effects
D006993:Hypnotics and Sedatives; D008874:Midazolam