Prospective cohort study on thirty day outcome of perforation peritonitis at the University Teaching Hospitals, Lusaka, Zambia

Perforation peritonitis is a common surgical emergency seen by surgeons; it remains a life threatening condition with high morbidity and mortality. At the University Teaching Hospitals (UTH), the morbidity for gastro-duodenal perforation has not been studied. Furthermore, based on the available literature at the main referral centre in Zambia the outcome of perforation peritonitis following jejunal, ileal, colonic perforation, with the use of the Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (POSSUM) scoring system, was unknown. The study aimed to determine the site of perforation, the post-operative outcomes of leakage, wound dehiscence, re-laparotomy and mortality in relation to the site of perforation, and related the POSSUM score to the outcome.
This was a prospective observational study conducted at the Department of Surgery of the University Teaching Hospitals, Lusaka from July 2018 to March, 2019. During this period a total of 100 patients undergoing exploratory laparotomy for spontaneous perforation peritonitis were included. The morbidity and mortality risks were calculated using the POSSUM and P-POSSUM.
Sites of perforation were:-Gastric (n=49) followed by ileal (n=36), colonic (n=8), jejunal (n=3) duodenal (n=1), combined ileal and colonic (n=1), unidentified (n=1) and urinary bladder (n=1). The mean age was 37.24 (range 18 to 78 years). There were 77 males and 23 females ratio 3.34:1. Thirty six died (36% mortality rate) in the post-operative period and morbidity rate was 17.19%. Post-operative outcomes included leak 9%, wound dehiscence 3%, and re-laparotomy 17%. Thirty four percent of patients needed admission to intensive care unit (ICU) and twenty nine out of thirty four (85.29%) patients who were admitted to ICU died. Hospital stay was 9.53±6.86 days. The most common cause of death was septic shock in nineteen (52.78%) followed by sepsis, and acute kidney injury. The predicted morbidity score correlated positively with size of perforation and the POSSUM score, although not statistically significant. Number of perforation, site of perforation, physiological and operative score positively correlated with mortality score and was statistically significant (p<0.05).
Gastric perforation was the leading cause of perforation peritonitis, with the highest morbidity and mortality at UTH; followed by the ileum, colon, jejunum, duodenum and lastly, urinary bladder. The commonest postoperative outcome was re-laparotomy followed by leak and abdominal wound dehiscence. The commonest cause of mortality in perforation peritonitis was septic shock followed by sepsis. The POSSUM score significantly predicted mortality in perforation peritonitis in patients at the UTH. However, it could not significantly predict the outcome of leak, wound dehiscence and re-laparotomy.