Risk of perforation increases with delay in recognition and surgery for acute appendicitis

Abstract

Background

Appendicitis remains a common indication for urgent surgical intervention in the United States, and early appendectomy has long been advocated to mitigate the risk of appendiceal perforation. To better quantify the risk of perforation associated with delayed operative timing, this study examines the impact of length of inpatient stay preceding surgery on rates of perforated appendicitis in both adults and children.

Methods

This study was a cross-sectional analysis using the National Inpatient Sample and Kids’ Inpatient Database from 1988–2008. We selected patients with a discharge diagnosis of acute appendicitis (perforated or nonperforated) and receiving appendectomy within 7 d after admission. Patients electively admitted or receiving drainage procedures before appendectomy were excluded. We analyzed perforation rates as a function of both age and length of inpatient hospitalization before appendectomy.

Results

Of 683,590 patients with a discharge diagnosis of appendicitis, 30.3% were recorded as perforated. Over 80% of patients underwent appendectomy on the day of admission, approximately 18% of operations were performed on hospital days 2–4, and later operations accounted for <1% of cases. During appendectomy on the day of admission, the perforation rate was 28.8%; this increased to 33.3% for surgeries on hospital day 2 and 78.8% by hospital day 8 (P < 0.001). Adjusted for patient, procedure, and hospital characteristics, odds of perforation increased from 1.20 for adults and 1.08 for children on hospital day 2 to 4.76 for adults and 15.42 for children by hospital day 8 (P < 0.001).

Conclusions

Greater inpatient delay before appendectomy is associated with increased perforation rates for children and adults within this population-based study. These findings align with previous studies and with the conventional progressive pathophysiologic appendicitis model. Randomized prospective studies are needed to determine which patients benefit from nonoperative versus surgically aggressive management strategies for acute appendicitis.

Introduction

Acute appendicitis is the most common indication for emergent surgical procedures in the United States. It affects approximately 250,000 patients each year [1], including 77,000 children [2]. Lifetime incidence for appendicitis is 8.6% for males and 6.7% for females, with maximal incidence at age 10–14 y in males and 15–19 in females [3]. After a period in which research focused primarily on options for surgical management, including laparoscopy [4] and selective nonoperative management [5], attention has increasingly turned to operative timing during the index admission. The conventional disease model for acute appendicitis was described in the early 20th century [6], [7], which proposes a progressive inflammatory process triggered by luminal obstruction of the appendix and culminating in perforation resulting from infection and ischemic necrosis. The presumptive time-dependent progression from appendiceal inflammation to rupture and abscess formation has served as the primary justification for prompt surgical intervention.

By this paradigm, delay of either antibiotic administration or appendectomy is deleterious, because it permits the pathologic process of appendicitis to proceed unchecked toward perforation. Impediments to immediate treatment may occur at multiple points as the patient proceeds through the health care system: in the pre-hospital setting, patients may not immediately seek treatment for symptoms; in the outpatient clinic or Emergency Department, providers may not diagnose the condition or refer appropriately; and even after diagnosis and hospital admission, facilities may be inadequately equipped or staffed to provide timely surgery. The present study sought to examine the specific interval of delay separating hospital admission and appendectomy using a nationwide discharge database. In comparing patients receiving same-day appendectomy with those whose operation was delayed, we were able to attempt to quantify the increased risk of an operative finding of perforated appendicitis resulting from delay in surgical treatment after hospital presentation.