No Risk From Delayed Appendectomy

Sept. 26, 2010— -- Appendectomies are the most common emergent medical procedure worldwide. And according to a new study, delaying emergency appendectomy for 12 hours or more appears to have no adverse effects during a 30-day follow-up period.

A retrospective review of almost 33,000 cases found that the rate of serious complications or death was about three percent, whether the operation occurred within six hours, six to 12 hours, or more than 12 hours after hospital admission. Overall morbidity was about 5.5 percent to 6 percent, regardless of the time from admission to surgery, Dr. Angela M. Ingraham of the American College of Surgeons (ACS) and co-authors reported.

Differences in operative duration and length of hospital stay, while statistically significant, were clinically inconsequential, the investigators wrote in the September issue of the Archives of Surgery.

Excluding disease severity from statistical models used in the analysis did not change the results, suggesting "that there truly is no relationship between time from surgical admission and negative outcomes after appendectomy in this retrospective cohort study," Ingraham and co-authors commented in a discussion of their findings.

"These data might help guide the use of the potentially limited operative and professional resources allocated for emergency surgical care," they added. "Such information will contribute to the efficient allocation of limited surgical resources without negatively affecting patient care."

Increased delay from onset of symptoms to surgery for acute appendicitis is associated with more advanced disease.

Recent developments in imaging and antibiotic therapy have improved preoperative assessment, affording more opportunities for nonoperative management and reducing the need for immediate surgery to prevent disease progression, the authors wrote in the introduction to their report.

Studies in the pediatric literature have indicated that delaying surgery and providing fluids and antibiotics does not increase the risk of adverse outcomes in children. Similar investigations in adults have not provided a definitive answer, although first-line antibiotic therapy for acute appendicitis proved to be safe in one study of carefully selected men.

In an attempt to clarify the risk of surgical delay in acute appendicitis, the authors reviewed data from the ACS National Surgical Quality Improvement Program database and identified all patients 16 or older who underwent appendectomy for a diagnosis of acute appendicitis from January 2005 through December 2008.

The study involved 32,782 patients, consisting of 24,647 (75.2 percent) patients who had an appendectomy within six hours of admission, 4,934 (15.1 percent) patients who underwent surgery six to 12 hours after admission, and 3,201 (9.8 percent) patients who had the operation more than 12 hours after being admitted.

The patients had a mean age of 38, and men accounted for 53.9 percent of the study population. Men and white patients had shorter delays before having surgery, and chronic comorbid conditions were associated with increased delays from admission to the induction of anesthesia.

The authors reported that 83.4 percent of the patients had simple appendicitis and 16.6 percent had complicated appendicitis. Three-fourths of the patients underwent laparoscopic appendectomy.

Overall, the time from admission to induction averaged 4.95 hours. The delay averaged 1.51 hours in patients who had surgery within six hours, 8.45 hours in patients whose surgery was delayed for six to 12 hours, and 26.08 hours for patients whose surgery was delayed for more than 12 hours.

Duration of surgery averaged 55 minutes in patients who had the longest delays to induction of anesthesia, compared with 50 to 51 minutes in the other two groups. The postoperative length of stay averaged 2.2 days for more-than-12-hours groups and 1.8 days for the other two groups. Though statistically significant, the differences were not clinically significant, the authors wrote.

Overall morbidity was 5.4 percent to 6.1 percent in the three groups, and serious morbidity/death was 3.6 percent in the six-to-12-hours group versus 3.0 percent in the other two groups.

The study provided a clear answer to the question of whether time to surgery influences outcome in emergent appendectomy, Dr. John G. Hunter wrote in an commentary accompanying the study.

"The patients with a delay from admission to operation greater than 12 hours fared no worse and no better than those who underwent appendectomy less than six hours from the time of admission," said Hunter, of the Oregon Health & Science University in Portland.

"These data provide the justification for performing appendectomy as soon as is convenient [usually in the morning] for acute appendicitis."

The study validated the practice of treating acute appendicitis "urgently rather than emergently," Hunter continued. A hospital can save money by minimizing the late-night surgical and anesthesia staffs. Surgeons benefit from a good night's sleep and avoid the fatigue of a sleepless night spent caring for a patient with acute appendicitis.

"At the end of the day, it is clearly a win-win-win situation when the interests of the patient, the surgeon, and the hospital are in complete alignment around such as shift in surgical practice," Hunter wrote in conclusion.

There were limitations to the study. Identification of patients with acute appendicitis was made using CPT operative codes in combination with postoperative ICD-9 diagnostic codes; CT scan imaging or pathology reports were unavailable in the ACS NSQIP database, which also does not contain data about patient symptoms, insurance status, emergency department presentation date or time, or reasons for potential delays to surgery.

"Thus, we could not control for any delay owing to a patient deferring initial presentation to the hospital despite having symptoms," Ingraham and co-authors wrote. This was likely to have a minimal effect, they added, because "the duration of time prior to a patient's presentation contributes more significantly to disease severity than the delay from hospital presentation to operation."

They also noted that the ACS NSQIP does not collect data on timing or appropriateness of antibiotics or intravenous fluids administered before an appendectomy, which represents standard of care and if not received could result in elevated complication rates.

Finally, there might be confounding by the timing of the operation based on unmeasured factors when assessing the patient. "Thus, earlier operations on patients of concern (or delaying operations on patients without concern) might negate any observable differences in outcome associated with delays," they wrote.