# Safe discharge on the second postoperative day after major colorectal surgery: a decision-making strategy based on quantitative serological data

## TL;DR

This study identifies C-reactive protein thresholds on day 2 after colorectal surgery to safely discharge patients early, reducing hospital stays without increasing complication risks.

## Contribution

The study provides specific C-reactive protein cutoff values on postoperative day 2 for predicting complications, enabling safe early discharge decisions.

## Key findings

- A C-reactive protein cutoff of 140 mg/L on postoperative day 2 had a 98.6% negative predictive value for anastomotic leak.
- Patients with C-reactive protein levels below 140 mg/L on day 2 could be safely discharged with high confidence in avoiding complications.
- The study found comparable predictive accuracy for postoperative day 2 and 3 measurements in identifying complications.

## Abstract

Enhanced Recovery After Surgery (ERAS) has enabled early patient discharge, but reliable biomarkers are needed to support safe early discharges. C-reactive protein levels have been reported as good markers for early anastomotic leak detection and also for overall complications, but there is no consensus yet on its quantification nor day of analysis.

This study aimed to determine the C-reactive protein cutoff values at postoperative day (POD) 2–4 associated with the lowest risk of postoperative complications.

Single-center, retrospective study.

Tertiary hospital.

Patients operated on between 2019 and 2022.

Surgery for colorectal cancer.

C-reactive protein on postoperative days 2–4 and the delta difference between postoperative days 3 and 2 were measured, identifying the best cutoff value for each postoperative complication. Receiver-operating characteristics curves were generated and the area under the curve was analyzed for each postoperative day measurement.

A total of 434 patients were included, median age was 72 (62–80) years. On postoperative day-2, the cutoff values for overall morbidity, surgical complications, medical complications, and anastomotic leak were 139.2 mg/L, 144.4 mg/L, 140 mg/L, and 170 mg/L, respectively. POD3 and 2 were both safe (area under the curve of 0.7507 and 0.7466, respectively). The negative predictive values using a C-reactive protein POD2 cutoff value of 140 mg/L were 80.6%, 91.5%, 87.6%, and 98.6% for global, medical, surgical complications, and anastomotic leak, respectively.

Retrospective study.

Carefully selected, motivated, and clinically suitable patients could be offered discharge on POD2 if their C-reactive protein levels are below 140 mg/L, with a very high negative predictive value for anastomotic leak and other postoperative complications. This decision should be made in collaboration with patients, considering clinical assessment and logistic factors.

The online version contains supplementary material available at 10.1007/s10151-026-03300-0.