Transdermal nitroglycerin as an adjuvant to patient-controlled morphine analgesia after total knee arthroplasty.
BACKGROUND
Nitroglycerin (NTG) has been shown to be a useful adjunct for pain treatment without increasing adverse side effects. The effects of NTG on postoperative morphine consumption after knee replacement were evaluated.


METHODS
After undergoing total knee replacement, patients receiving patient-controlled morphine analgesia were randomly assigned to receive either an NTG or a placebo patch. The blinded investigator assessed each patient using a visual analogue scale at rest and while moving, as well as the patient's morphine requirements, sedation score, sleep quality, nausea and vomiting, vital signs and postoperative bleeding.


RESULTS
Two of the patients in the NTG group suffered postoperative myocardial infarctions after removal of the patch. Because of these two serious adverse effects, the study was stopped prematurely. In the subset of patients studied, NTG conferred no advantage over placebo in pain control (visual analogue scale at rest or during movement) and in satisfaction scores.


CONCLUSIONS
The use of NTG patches conferred no advantage over the use of placebo in patients receiving patient-controlled morphine analgesia after total knee replacement. Two myocardial infarcts occurred in this group. Therefore, the safety of postoperative NTG patch use for pain control must be questioned.
Orbach-Zinger
Sharon
S
Department of Anesthesia, Rabin Medical Center, Beilinson Campus, Petach Tiqvah, Israel. sharonorbach@yahoo.com
Lenchinsky
Artium
A
Paul-Kesslin
Lesley
L
Velks
Steven
S
Salai
Moses
M
Eidelman
Leonid A
LA
D000279:Administration, Cutaneous; D000368:Aged; D000369:Aged, 80 and over; D016058:Analgesia, Patient-Controlled; D000700:Analgesics / Q000627:therapeutic use*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects; D016009:Chi-Square Distribution; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000627:therapeutic use*; D005996:Nitroglycerin / Q000008:administration & dosage*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D011183:Postoperative Complications / Q000188:drug therapy / Q000503:physiopathology
D000700:Analgesics; D009020:Morphine; D005996:Nitroglycerin