Does Time Affect Rupture in Appendicitis?

Abstract & Commentary

By Frank W. Ling, MD, Clinical Professor, Dept. of Obstetrics and Gynecology, Vanderbilt University School of Medicine, Nashville, is Associate Editor for OB/GYN Clinical Alert.

Dr. Ling reports no financial relationship to this field of study.

Synopsis: Rupture risk in cases of appendicitis was less than 2% when symptoms went untreated for less than 36 hours, whereas the risk exceeds 5% when the duration of symptoms is more than 36 hours.

Source: Bickell NA, et al. How time affects the risk of rupture in appendicitis. J Am Coll Surg. 2006;202:401-406.

A retrospective chart review in 219 of 731 randomly selected cases of appendicitis was conducted at 2 municipal/tertiary care hospitals. Compared to the rupture rate of < 2% when the untreated symptoms were of 36 hours duration or less, patients with symptoms beyond 36 hours had a rate of rupture exceeding 5% (RR = 6.6).

Other significant factors for ruptured appendix included age 65 years and older (RR = 4.2), fever > 38.9°C (RR = 3.6), and tachycardia > 100 bpm (RR = 3.4). The time between the first physician evaluation and treatment was statistically shorter (7.1 vs 10.9 hours) if the patient presented to the Emergency Department. Also, the duration to treatment was shorter (6.3 vs 11.3 hours) if the physician’s primary differential diagnosis was appendicitis. Interestingly, patients sent for CT scan had delayed time to surgery compared to those patients who did not have a CT scan (18.6 vs 7.1 hours).


I really like studies that try to answer clinical questions that make me wonder. This is one such study. Although retrospective, it tries to address the always-difficult concern of: "Gee, I wonder what will happen if surgery for the suspected appendicitis is delayed?" Data from the 2000 National Hospital Discharge Survey suggest that the overall ruptured appendix rate is approximately 13%. With the attendant peritonitis, sepsis, and even mortality, it behooves us to try to avoid appendiceal rupture if at all possible.

For the first 36 hours after the onset of symptoms, the authors found a 0-2% risk of rupture in each 12-hour period. The risk rose and remained stable at 5% during subsequent 12-hour periods. The clinical message should not be lost on those who primarily look after the healthcare of women. Even though acute appendicitis typically is a general surgical problem, the differential diagnosis of this condition in women is primarily gynecologic. Given the classic history, physical, and laboratory findings in cases of appendicitis, the gynecologic disorders can usually be ruled out in a timely fashion.

Even if we are remote from the patient, we regularly use ultrasound reports to image ovarian cysts, the pregnancy test to rule out ectopic pregnancy, and the complete blood count to provide insight into blood loss as well as leukocytosis. By no means would I advocate making a presumptive diagnosis without a thorough history and physical, but the primary gynecologic etiologies for right lower quadrant pain can be ordered and performed by the time we arrive to see the patient. My take-home message from this article is that we need to minimize our role in any undue delay that might lead to a ruptured appendix. It is my opinion that we can greatly help our colleagues in the Emergency Department or on the General Surgery service with timely and efficient use of the skills and tests available to us. This article helps us focus on that effort.