Comparison of lorazepam alone vs lorazepam, morphine, and perphenazine for cardiac premedication.
OBJECTIVE
To compare the effects of two premedication regimens on cardiorespiratory variables, sedation, and anxiety in patients scheduled for coronary artery bypass graft (CABG) surgery.


METHODS
This was a prospective randomized, double-blind clinical trial. Sixty-eight patients were monitored for 1.5 hr before and 2.0 hr after premedication with lorazepam (0.03 mg.kg-1 sl), morphine (0.15 mg.kg-1 im), and perphenazine (0.05 mg.kg-1 im) [Group 1], or with lorazepam (0.03 mg.kg-1 sl) and saline (1.5 ml im) [Group 2]. All were continuously monitored with a 12-lead ECG ST monitors, respiratory inductive plethysmography (RIP), digital pulse oximetry, intra-arterial blood pressure, and arterial blood gas analysis. Sedation and anxiety scores were also recorded.


RESULTS
The incidence and duration of myocardial ischaemia was low and similar in Groups 1 and 2. Patients in Group 1, but not in Group 2, had a greater number of events (P < 0.04) and duration (P < 0.02) of O2 desaturation; higher PaCO2 (P < 0.001), and more haemodynamic events (P < 0.006) after premedication when compared with baseline. There was no difference in RIP or ECG variables between the two groups. Following premedication, both groups reported reduced anxiety scores and elevated sedation scores (P < 0.01), with sedation greater in Group 1 than in Group 2 (P < 0.01).


CONCLUSIONS
In CABG patients, premedication with lorazepam provides adequate anxiolysis and sedation, and the addition of morphine and perphenazine results in elevated PaCO2, arterial haemoglobin desaturation, and potentially adverse haemodynamic changes.
Saccomanno
P M
PM
Department of Anaesthesia, Toronto Hospital, University of Toronto, Ontario, Canada.
Kavanagh
B P
BP
Cheng
D C
DC
Katz
J
J
Sandler
A N
AN
D000368:Aged; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008140:Lorazepam / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D017202:Myocardial Ischemia / Q000209:etiology / Q000517:prevention & control*; D010546:Perphenazine / Q000008:administration & dosage*; D011229:Preanesthetic Medication; D011446:Prospective Studies; D012119:Respiration / Q000187:drug effects
D014151:Anti-Anxiety Agents; D006454:Hemoglobins; D009020:Morphine; D010546:Perphenazine; D008140:Lorazepam