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Three Part Question

In [young children with abdominal pain] how [useful is tenderness at McBurney's point] at [ruling in appendicitis]

Clinical Scenario

You are examining a 4 year old child with abdominal pain - with appendicitis at the top of your differential diagnosis. If the child is tender at McBurney's point is that enough to confirm your suspicion of appendicitis and prompt surgical referral?

Search Strategy

MEDLINE 1950 – Nov week 1 2007 using the OVID interface AND EMBASE 1980 to 2007 week 23
[{paediatric filter 2003 updated version for MEDLINE OVID interface} AND {exp Abdominal Pain/ OR exp Abdomen, Acute/ OR abdo$ pain.mp} AND {mcburney$ point.mp OR right iliac fossa tenderness.mp OR right iliac fossa.mp OR right lower quadrant tenderness.mp OR right lower quadrant.mp} AND {exp Physical Examination/ OR specific tenderness.mp OR localised tenderness.mp OR guarding.mp OR rebound tenderness.mp} AND {exp Appendicitis/ OR exp Appendix/ OR append$.mp}] LIMIT to human AND English

Search Outcome

MEDLINE:24 papers were found of which 18 were irrelevant or of insufficient quality.
EMBASE: 27 papers were found of which 26 were irrelevant or of insufficient quality (excluding duplicates)
The remaining 7 papers are shown in the table.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Alvardo, A 1985 USA	305 patients (4-80) admitted with abdominal pain suggestive of acute appendicitis. 227 confirmed acute appendicitis at appendicectomy.	Retrospective review	Tenderness in right lower quadrant in acute appendicitis	Sens 100%	No subset analysis for children No power calculation
				Spec 12%
				Predicitive value 100%
Nauta RJ and Magnant C 1986 USA	97 patients (2.5-91) admitted with pre-operative diagnosis of appendicitis. Histological diagnosis of appendicitis confirmed in 81%.	Cohort	Rebound tenderness in appendicitis	67%	No subset analysis for children. No power calculation 'Rebound tenderness' not specified at McBurney's point. Study type unclear - retrospective or prospective No data on sensiticity or specificity
			Rebound tenderness in non-appendicitis	39%
				Significant (95% CI 0.19 and 0.59)
Golledge J et al 1996 UK	100 patients (4-81) presented with right iliac fossa pain, with a provisional diagnosis of appendicitis.	Prospective cohort	Right iliac fossa tenderness	sens 100% spec 7% ppv 46%	No subset analysis for children. Small number in study - no power calculation
			Percussion tenderness over McBurney's pt	sens 57% spec 86% ppv 76%
Lane, R and Grabham, J 1997 UK	83 patients (7-80) admitted to surgical ward with tenderness in the right iliac fossa. Gold standard: histological diagnosis of appendicitis made in 59%	Prospective diagnostic test study	Modified sign - 1 min pressure on McBurney's point to illicit peritoneal irriation	sens 94%	No subset analysis for children Small study - no power calculation One difference of opinion between clinicians
				spec 71 %
Kharbanda AB et al 2005 USA	601 patients (3-18) presenting to paediatric Emergency Department with symptoms and signs of appendicitis. Post-surgery diagnosis of appendicitis 35%	Prospective cohort study	Maximal tenderness in right lower quadrant	sens 79.9% spec 40.7%	No power calculation Was part of creation of clinical decision rule to predict those children at low risk of appendicitis
				npv 77.9%
Bundy DG et al 2007 USA	Children with suspected appendicitis-which signs and symptoms increased likely diagnosis	Review of literature-42 studies met inclusion criteria, of which 25 were assigned quality level of 3 or above	Presence of fever	increases likelihood of appendicits (LR 3.4, CI 2.4-4.8)	Review article-meta-analysis not performed States that signs and symptoms are most useful in combination.
			Rebound tenderness	LR 3, CI 2.3-3.9
			Mid-abdominal pain migrating to RIF	LR range 1.9-3.1
			WCC <10	Decreases likelihood (LR 0.22, CI 0.17-0.30)

Comment(s)

Across the papers there was consistently high sensitivity - 79.9 - 100%. This implies that when there is no tenderness at McBurney's point appendicitis can be ruled out. The papers did not agree on specificity (7-100%) hence it must be concluded that positive tenderness does not rule in a diagnosis of appendicitis - simply peritonism which has many causes. A number of different methods used to elicit tenderness at McBurneys point (palpation, 1 minutes pressure, percussion) are proven to be comparable.

Clinical Bottom Line

Eliciting tenderness at McBurney's point is a valuable part of the abdominal examination - if negative appendicitis is a less likely diagnosis. However symptoms and signs are needed in combination.

References

1. Alvardo, A. A Practical Score for the Early Diagnosis of Acute Appendicitis Annals of Emergency Medicine 1986;15(5):557-64
2. Nauta RJ. Magnant C. Observation Versus Operation for Abdominal Pain in the Right Lower Quadrant. Roles of the Clinical Examination and the Leukocyte Count American Journal of Surgery 1986;151(6):746-8
3. Golledge J et al Assessment of peritonism in appendicitis Annals of the Royal Colledge of Surgeons of England 1996;78(1):11-4
4. Lane, R and Grabham, J A useful sign for the diagnosis of peritoneal irritation in the right iliac fossa Annals of the Royal College of Surgeons of England 1997;79(2):128-9
5. Kharbanda, AB et al. A clinical decision rule to identify children at low risk for appendicitis Pediatrics 2005;116(3):709-716
6. Bundy DG. Byerley JS. Liles EA. Perrin EM. Katznelson J. Rice HE. Does this child have appendicitis? JAMA 298(4):438-51, 2007 Jul 25