Acute appendicitis: influence of early pain relief on the accuracy of clinical and US findings in the decision to operate--a randomized trial.
OBJECTIVE
To determine the influence of early pain relief on the diagnostic performance of ultrasonography (US) and on the appropriateness of the surgical decision.


METHODS
A prospective randomized, double-blind placebo-controlled trial with morphine was conducted. A visual analog scale was used to evaluate pain in 340 patients aged 16 years or older. US was performed with a standardized protocol. Diagnosis was confirmed at histologic analysis or, in the patients released without surgery, at follow-up.


RESULTS
One hundred seventy-five patients were injected with morphine, and 165 were injected with the placebo. Pain relief was stronger in the morphine group. In the morphine group, US had lower (71.1%) sensitivity (difference, -9.5%; 95% CI, -18.5%, -0.5%) and higher (65.2%) specificity (difference, 11.4%; 95% CI, 1.0%, 21.8%). This group had also a higher positive predictive value (64.6%) and a lower negative predictive value (71.4%), but the differences between this group and the placebo group were not statistically significant. Among female patients, the decision to operate was appropriate more often in the morphine group (75.8%), but the difference between this group and the placebo group was not statistically significant (5.1%; 95% CI, -7.4%, 17.6%). In male patients and overall, opiate analgesia did not influence the appropriateness of the decision. The appropriateness to discharge patients without surgery was 100% in all groups.


CONCLUSIONS
Morphine does not improve US-based diagnosis of appendicitis.
Vermeulen
B
B
Emergency Department, Hôpitaux Universitaires de Genève, Switzerland.
Morabia
A
A
Unger
P F
PF
Goehring
C
C
Grangier
C
C
Skljarov
I
I
Terrier
F
F
D015746:Abdominal Pain / Q000188:drug therapy*; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D001062:Appendectomy; D001064:Appendicitis / Q000000981:diagnostic imaging* / Q000601:surgery; D016001:Confidence Intervals; D003657:Decision Making; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use; D010147:Pain Measurement; D010351:Patient Discharge; D010919:Placebos; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012737:Sex Factors; D014463:Ultrasonography
D000701:Analgesics, Opioid; D010919:Placebos; D009020:Morphine