# High intraoperative fluid load associated with prolonged length of hospital stay and complications after non-cardiac surgery in neonates

## TL;DR

Too much fluid during surgery in newborns leads to longer hospital stays and more complications, while less fluid is better for recovery.

## Contribution

High fluid load during non-cardiac surgery in neonates is newly shown to increase hospital stay and complications.

## Key findings

- High fluid load (Q5) increased odds of prolonged hospital stay by 2.6 times.
- High fluid load was linked to more complications and longer mechanical ventilation.
- Low fluid load (Q1) was associated with better postoperative outcomes.

## Abstract

Inappropriate perioperative fluid load can lead to postoperative complications and death. This retrospective study was designed to investigate the association between intraoperative fluid load and outcomes in neonates undergoing non-cardiac surgery. From April 2020 to September 2022, 940 neonates who underwent non-cardiac surgery were retrospectively enrolled and their perioperative data were harvested for further analysis. According to recorded intraoperative fluid volumes defined as ml.kg−1 h−1, patients were mandatorily divided into quintile with fluid load as restrictive (quintile 1, Q1), moderately restrictive (Q2), moderate (Q3), moderately liberal (Q4), and liberal (Q5). The primary outcomes were defined as prolonged length of hospital stay (LOS) (postoperative LOS ≥ 14 days), complications beyond prolonged LOS, and 30-day mortality. Secondary outcomes included postoperative complications within 14 days of hospital stay. The intraoperative fluid load was in Q1 of 6.5 (5.3–7.3) (median and IQR); Q2: 9.2 (8.7–9.9); Q3: 12.2 (11.4–13.2); Q4: 16.5 (15.4–18.0); and Q5: 26.5 (22.3–32.2) ml.kg−1 h−1. The odd of prolonged LOS was positively correlated with an increase fluid volume (Q5 quintile: OR 2.602 [95% CI 1.444–4.690], P = 0.001), as well as complications beyond prolonged LOS (Q5: OR 3.322 [95% CI 1.656–6.275], P = 0.001). The overall 30-day mortality rate was increased with high intraoperative fluid load but did not reach to a statistical significance after adjusted with confounders. Furthermore, the highest quintile of fluid load (26.5 ml.kg−1 h−1, IQR [22.3–32.2]) (Q5 quintile) was significantly associated with longer postoperative mechanical ventilation time compared with Q1 (Q5: OR 2.212 [95% CI 1.101–4.445], P = 0.026).

Conclusion: Restrictive intraoperative fluid load had overall better outcomes, whilst high fluid load was significantly associated with prolonged LOS and complications after non-cardiac surgery in neonates.

Trial registration: Chictr.org.cn Identifier: ChiCTR2200066823 (December 19, 2022).
What is Known:• Inappropriate perioperative fluid load can lead to postoperative complications and even death.What is New:• High perioperative fluid load was significantly associated with an increased length of stay after non-cardiac surgery in neonates, whilst low fluid load was consistently related to better postoperative outcomes.

What is Known:

• Inappropriate perioperative fluid load can lead to postoperative complications and even death.

What is New:

• High perioperative fluid load was significantly associated with an increased length of stay after non-cardiac surgery in neonates, whilst low fluid load was consistently related to better postoperative outcomes.