Characteristics of perforated appendicitis: effect of delay is confounded by age and gender.

INTRODUCTION: The effect of age and gender on time to perforation in acute appendicitis has not been well characterized. This study examined the relationship between duration of disease and appendiceal perforation in different subgroups of age and gender.
METHODS: This study is a retrospective analysis of 380 patients who underwent an appendectomy from January 2000 to June 2005 at a rural teaching hospital.
RESULTS: Factors associated with perforated appendicitis included age, symptom duration, CT scan, and distance from the hospital. Factors associated with increased patient time included age, temperature >101.5 F, and referral from an outside institution. Factors associated with shorter system time included right lower quadrant tenderness, classic or severe presentation, and leading diagnosis of acute appendicitis. Preoperative CT scan increased system time by approximately 3 h. Analyzing symptom duration and time to perforation, males have a higher prevalence of perforated appendicitis compared to females with similar duration of symptoms. In patients older than 55 years of age, 29% had perforated appendicitis at 36 h of symptoms and 67% at 36 to 48 h of symptoms. In a multivariate regression analysis, age greater than 55 years (odds ratio (OR) 3.0, P value 0.007), fever (OR 4.3, P 0.007), and symptom duration more than 24 h (OR 4.1, P 0.001) were significant predictors of perforated appendicitis.
CONCLUSIONS: There is an early risk of perforated appendicitis even within the first 36 h of symptoms. This risk appears to be higher in males and patients older than 55 years, a quarter of whom are perforated within the first 36 h of symptom duration. Additionally, perforation in acute appendicitis may be more of a continuous phenomena worsening exponentially with duration of symptoms rather than a threshold phenomenon.