The association between high‐volume intraoperative fluid administration and outcomes among pediatric patients undergoing large bowel resection

This retrospective audit of medical records aims to test the hypothesis that high-volume fluid administration would be associated with worsened postoperative outcomes including length of stay (LOS), time to first meal, duration of PACU stay and supplemental oxygen requirement. 197 patient encounters were included. Patients were stratified into two groups: a high-volume group who received greater than the 90th percentile fluids and a low-volume group who received less than the 90th percentile fluids. To allow comparison, a standardized fluid administration calculation was devised which took into account maintenance fluid requirements, surgical duration and fluid type. This derived unit of fluids was expressed as hours of maintenance fluids. In addition, propensity score matching was performed between patients in the high-volume group and all other patients based on 4 factors: Estimated blood volume, ASA, open procedures and procedure time. 14 patients in the high-volume group were matched to 109 control patients. The matched groups were then compared for the following binary outcomes: LOS greater than 6 days, time to first meal greater than 4 days and supplemental oxygen greater than 24 hours.

An association was found between LOS, the primary outcome, and high-volume fluid administration. The study was able to show using linear regression that for each 1 hour increase in fluids (based on the derived standardised unit) there was an increase in LOS of 0.12 days, translating to an additional day for every 8.3 standardised hours of maintenance fluids. In addition, high-volume fluid was associated with LOS greater than 6 days after adjusting for ASA, EBL and packed cell transfusion. High-volume fluid administration was also associated with increased supplemental oxygen need after adjusting for confounders. Patients with high-volume fluid administered were more likely than matched controls to have LOS greater than 6 days, a time to first meal greater than 4 days and supplemental oxygen need greater than 24 hours.

Take Home Message

The authors state that excess fluid administration may result in fluid oedema which can depress cellular and tissue function with bowel oedema known to impair peristalsis and, in animal studies, affect the integrity of bowel anastomosis. Liberal fluids have also been shown in clinical studies in adults to increase anastamotic leak, wound infection, surgical complications and pulmonary oedema. Restrictive and goal directed fluid strategies are associated with reduced surgical complications in adult patients undergoing colorectal and other intraabdominal surgery. These strategies have been incorporated into Enhanced Recovery After Surgery (ERAS) protocols which in turn have been shown to reduce cardiovascular and pulmonary complications after colorectal surgery. According to the authors, there is little evidence on perioperative fluid administration practices in children and little evidence to guide fluid regimes in similar paediatric patients. This study takes a first step in examining the potential for liberal fluid regimens to cause harm. The retrospective nature of this study means that it is unable to control for confounders. It also means that some important information was not able to be collected such as patient comorbidity. This is acknowledged by the authors. Propensity score matching yielded statistically significant differences in the above-mentioned binary outcomes. It remains to be seen whether these differences would persist in a prospectively matched cohort. However, the finding of an association between high-volume fluid regimens and increased length of stay was both statistically and clinically significant. This association warrants further investigation to look for causative factors, other potential associations and identify which fluid regimens are associated with better outcomes. The average age of the patients was 15.8 years with an average weight of almost 54 kg. A study of a younger, smaller cohort would be of particular interest.

Reviewed by Catherine Olweny