Table 4

Author, date, and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study weaknesses
PRCT = prospective randomised controlled trial.
Zoltie and Cust, 1986, UK¹	288 patients with acute abdominal pain	PRCT	Pain relief	Proportional to dosage
	Buprenorphine 200 μg v buprenorphine 400 μg v placebo		Clinical diagnosis	Not affected
Attard et al, 1992, UK²	100 consecutive patients admitted to a surgical firm	PRCT	Pain score	Significantly better with papaveretum (p<0.0001)	Papaveretum no longer used
	Papaveretum 20 mg v normal saline		Tenderness score	Significantly better with papaveretum (p<0.0001)
			Incorrect diagnosis	2 after papaveretum v 9 after saline
Pace and Burke, 1996, USA³	71 adult patients with acute, atraumatic abdominal pain in an emergency department	PRCT	Pain score	Significantly better with morphine (p<0.001)
			Accuracy of provisional diagnosis	No difference
	Morphine IV (35) v normal saline (36)		Accuracy of final diagnosis	No difference
LoVecchio et al, 1997, USA⁴	48 patients with acute abdominal pain	PRCT	Change in physical examination	Significant changes in both morphine groups	Very small numbers
	Morphine 10 mg v morphine 5 mg v placebo		Delay in diagnosis	No diagnostic delay in any group
Vermeulen et al, 1999, Switzerland⁵	340 patients aged 16 years or more with suspected appendicitis	PRCT	Pain relief	Greater in morphine group
	Morphine IV (175) v placebo (165)		Sensitivity and specificity of ultrasound diagnoses	No significant difference
			Appropriateness of the decision to operate	No significant difference