Three Part Question
In [adults with suspected appendicitis] does [a single white cell count] aid [diagnosis]?
A 24 year old man presents to the Emergency Department with a history and examination consistent with appendicitis. On referral, the duty surgeon requests a full blood count. You wonder whether it will aid the diagnosis.
Medline 1966-06/02 using the OVID interface.
[(exp Appendicitis OR acute appendicitis.mp) AND (exp Haematological tests OR exp Leukocyte count or leukocyte count$.mp OR neutrophil count$.mp OR white cell count$.mp OR inflammatory parameter$.mp or white blood count$.mp)] LIMIT to human AND English.
176 papers were found, of which 171 were irrelevant or of insufficient quality for inclusion. The remaining 5 papers are shown in the table.
|Author, date and country
||Study type (level of evidence)
|Miskowiak J et al,|
|238 patients (>15) admitted with suspected acute appendicitis||Diagnostic test study, blinded||WCC>9 000. Histology ||Sens 84%; Spec 66%; LR+ 1.26; LR- 0.95||No gold standard|
|Lau WY et al,|
|1389 patients (1-87), with right lower abdominal pain, consistent with appendicitis
769 aged 15-65
Non-operative group followed up at 2 and 6 weeks||Diagnostic test study, blinded||WCC>10 000 (group 15-65). Histology|| Sens 88%; Spec 76%; LR+ 3.7; LR- 0.29||No gold standard|
|Dueholm S et al,|
|204 patients (15-45) admitted with suspected acute appendicitis||Diagnostic test study, blinded||WCC>11 000 ||Sens 76%; Spec 74 %; LR+ 2.92; LR- 0.32||No gold standard|
|WCC>9 000. Histology||Sens 83%; Spec 50%; LR+ 1.66; LR- 0.34|
|Amland PF et al,|
|110 patients (13-33) admitted with suspected acute appendicitis||Diagnostic test study, blinded||WCC>10 000. Histology||Sens 68%; Spec 69%; LR+ 2.19; LR- 0.69||No gold standard|
|Andersson RE et al,|
|502 patients (10-86) admitted with suspected acute appendicitis||Diagnostic test study||WCC>10 000. Histology||Sens 78%; Spec 68%; LR+ 2.44; LR- 0.33||No gold standard
All the reviewed studies have the weakness of no gold standard diagnostic test against which to compare the non-operative group. Only one study undertakes follow up of its non-operative group, with a single study formally recognising the fact that some abdominal pain, not requiring laparotomy, may have originated from the appendix.
While all the studies seem to produce broad agreement as to the sensitivity and specificity of an isolated white cell count, they are not truly comparable due to the differing selection criteria of patients, age ranges and clinical management. In addition there is a wide prevalence of disease between the groups.
Clinical Bottom Line
A single white cell count is neither sensitive nor specific in the diagnosis of appendicitis.
- Miskowiak J, Burcharth F. The white cell count in acute appendicitis. A prospective blind study. Dan Med Bull 1982;29(4):210-1.
- Lau WY, Ho YC, Chu KW et al. Leucocyte count and neutrophil percentage in appendicectomy for suspected appendicitis. Aust N Z J Surg 1989;59(5):395-8.
- Dueholm S, Bagi P, Bud M. Laboratory aid in the diagnosis of acute appendicitis. A blinded, prospective trial concerning diagnostic value of leukocyte count, neutrophil differential count, and C-reactive protein. Diseases of the Colon and Rectum 1989;32(10):855-9.
- Amland PF, Skaane P, Ronningen H et al. Ultrasonography and parameters of inflammation in acute appendicitis. A comparison with clinical findings. Acta Chir Scand 1989;155(3):185-9.
- Andersson RE, Hugander AP, Ghazi SH, et al. Diagnostic value of disease history, clinical presentation, and inflammatory parameters of appendicitis. World J Surg 1999;23(2):133-40.