Evaluation of a severity score to predict the prognosis of Fournier's gangrene.

Objective: To determine the validity of a Fournier's gangrene severity index (FGSI), developed to assign a numerical score describing the severity of FG, and evaluate factors in the survival of patients with FG.
Patients and Methods: We retrospectively reviewed 51 patients diagnosed with FG between 1994 and 2006. Data were collected on their medical history, which included vital signs (temperature, heart and respiratory rates) and metabolic variables (sodium, potassium, creatinine, bicarbonate levels, haematocrit, and white blood cell count). We computed a score relating to the severity of the disease at the time, and compared it to other features according to whether the patient survived or died. The different prognostic factors were assessed by univariate analysis with the Mann-Whitney U and Kendall A-B tests.
Results: Of the evaluated 51 inpatients, eight died (16%) and 43 survived (84%). The median (range) age was 63 (17-85) years and the median time from the onset of the symptoms until the admission to the emergency room was 7.8 (1-60) days. The mean hospital stay was 33 (2-90) days and 17 patients were admitted to the intensive-care unit for a mean of 4.5 days. There was no statistically significant difference between the groups. Body surfaces involved were the scrotum in five patients (10%), the penis and scrotum in 11 (22%), the scrotum and perineum in 30 (59%) and the abdominal wall in five (10%). There was no statistically significant difference in the distribution in those who survived or died (P = 0.131). The median age of 60 (17-81) years in the survivors was significantly lower than that of 73.5 (50-85) years in those who died (P = 0.02). There was no significant difference (P = 0.06) between the number of repeated debridements in the survivors (3.23) and those who died (5.25). The mean (range) FGSI score for survivors was 6.7 (0-14), vs 8.7 (6-13) for those who died (P = 0.12). The only laboratory variables associated with death were serum bicarbonate (P = 0.04) and serum sodium (P = 0.02) levels.
Conclusions: FG is an unpredictable disease process with wide variability in its presentation. In our experience, the FGSI gives no indication of the likelihood of survival, but the risk factors for predicting the severity of FG seem to be greater in older patients and those with high sodium and low bicarbonate levels.