Intra-abdominal sepsis and septic shock in critically ill surgical patients have a high mortality rate. Fluid therapy is one of the initial resuscitation measures, but it can contribute to poor treatment outcomes through fluid overload and accumulation of sodium and chloride. This study aimed to examine an association among cumulative fluid balance and serum sodium and chloride levels in the intensive care unit (ICU) and in-hospital mortality in critically ill surgical patients with intra-abdominal sepsis after emergency surgical treatment. The study was designed as a retrospective, cohort study.

Data were collected and analyzed from 100 critically ill surgical patients with intra-abdominal sepsis, consecutively admitted to the ICU of a university medical center. Patients were immediately subjected to surgical treatment for intra-abdominal sepsis upon hospital admission. Postoperative care continued in the ICU for at least seven days. Patients who were hospitalized in the ICU for less than seven days, immunocompromised, and patients with intra-abdominal sepsis as a result of previous abdominal surgery were not included in the study. Data related to daily fluid intake and loss were taken from medical records where these data are recorded daily. Intake included both enteral and parenteral, while fluid losses from the body included urine, losses through drains, and nasogastric tube. The cumulative fluid balance was calculated for the periods from days 1 to 3 of treatment, and from days 1 to 7 of treatment. Data on serum sodium and chloride levels were recorded at the same time points as for cumulative fluid balance. The impact of variables on treatment outcomes was determined using binary logistic regression. The predictive quality of the variables on the outcome was assessed using ROC curves.

Inclusion Criteria:

• critically ill surgical patients with intra-abdominal sepsis/septic shock consecutively admitted to a university medical center
• Patients who were immediately subjected to surgical treatment for intra-abdominal sepsis/sepstic shock upon hospital admission and postoperative care continued in the ICU for at least seven days

Exclusion Criteria:

• Patients who were hospitalized in the ICU for less than seven days
• immunocompromised
• patients with intra-abdominal sepsis as a result of previous abdominal surgery were not included in the study

100 critically ill surgical patients with intra-abdominal sepsis, consecutively admitted to the ICU of a university medical center. Patients were immediately subjected to surgical treatment for intra-abdominal sepsis upon hospital admission. Postoperative care continued in the ICU for at least seven days.