Fluid balance following laparotomy for hollow viscus perforation: A study of morbidity and mortality.

Background: In critically unwell patients requiring emergency abdominal surgery, the relationship between the volume of intravenous fluid given, the subsequent fluid balance and morbidity or mortality is poorly delineated. This study aimed to elucidate this relationship. Materials and methods: Retrospective analysis of data from a single medical center. Patients presenting emergently to hospital requiring abdominal surgery for perforation of a hollow viscus with subsequent intensive care unit admission were identified. Clinicopathological, surgical and postoperative data were collected. The volume of intravenous fluid therapy was recorded and fluid balance was calculated from hospital arrival to the end of postoperative day (PoD) 5. Univariate and multivariate logistic regression was used to identify variables associated with patient morbidity or mortality. Results: Overall 51 patients met inclusion criteria. On univariate analysis, low serum sodium was associated with an increased incidence of postoperative complications. Postoperative mortality was associated with high postoperative serum sodium and low albumin, increasing age, pre-existing hypertension and ischaemic heart disease. In patients who died, a positive fluid balance was found on PoD 1-4 whilst in patients who survived, their fluid balance was negative. On multivariate analysis, positive postoperative fluid balance and increasing age were independently associated with an increased risk of death. Conclusions: Larger volumes of postoperative intravenous fluid and greater positive postoperative fluid balance are associated an increase in postoperative mortality but not morbidity following emergency abdominal surgery for perforation of a hollow viscus.