[Heart rate variability as a predictor of severity of acute appendicitis: a prospective analytical study]

To evaluate whether heart rate variability (HRV) is a predictive of severity of acute appendicitis.

A cross-sectional and prospective study was conducted in 144 patients who underwent appendectomy. The sample included 111 patients with complicated appendicitis and 33 ones with uncomplicated appendicitis. Clinical data, HRV parameters and their predictive capacity for complicated appendicitis were evaluated. HRV was measured as the difference between minimum and maximum heart rate over three minutes before anesthetic induction. The student's t-test and the ROC curve were used for statistical analysis.

Patients with complicated appendicitis had longer duration of illness (2.05±0.71 vs. 1.15±0.36 days, p=0.001) and higher leukocyte count (15.696.63±4.530.74 vs. 13.465.52±3.375.71, p=0.010). HRV was significantly lower in complicated cases (10.24±4.72 vs. 14.58±4.78, p=0.001). The area under the ROC curve was 0.750 (95% CI: 0.665-0.834) that indicated moderate predictive capacity of HRV for complicated appendicitis.

Heart rate variability was associated with severity of acute appendicitis, and HRV was lower in complicated cases. ROC curve suggests that HRV may be moderate predictor for identifying complicated appendicitis.