# Defining, Evaluating, and Managing Postoperative Respiratory Depression: An e-Delphi Study

## TL;DR

This study defines postoperative respiratory depression and establishes expert consensus on its diagnosis and management to improve patient safety.

## Contribution

The study provides a standardized definition and management framework for postoperative respiratory depression through expert consensus.

## Key findings

- A consensus definition of PORD includes respiratory rate <10 breaths/min, SpO₂ <90%, or PaCO₂ >50-55 mmHg within 48 hours post-surgery.
- Key risk factors include advanced age, obesity, pre-existing respiratory disease, and certain anesthetic agents.
- Consensus supports continuous pulse oximetry and capnography for diagnosis and the need for reversal agents that preserve analgesia.

## Abstract

Background: Postoperative respiratory depression (PORD) is a common but underreported postoperative pulmonary complication with potentially serious short- and long-term consequences. Despite its prevalence, no universally accepted expert definition exists, making identification, diagnosis, and epidemiologic study challenging.

Methods: An e‑Delphi study was conducted with a multidisciplinary panel of 10 board‑certified physicians in anesthesiology, surgery, pulmonology, emergency medicine, and critical care. Over four rounds, panelists anonymously rated 20 literature‑derived statements on PORD definition, diagnosis, risk factors, monitoring, prevention, and management using a 1-10 Likert scale. A consensus threshold of ≥70% agreement was applied. Panelists could suggest revisions, and statements were ranked by relative importance.

Results: Nineteen of 20 statements (95%) achieved consensus; 15 reached consensus within two rounds, and four additional statements reached consensus by round four. The most important statement defined PORD as a clinically significant reduction in neural drive to breathe, indicated by respiratory rate <10 breaths/min, SpO₂ <90%, or PaCO₂ >50-55 mmHg within 48 h post-surgery, with early cases often linked to anesthesia. Key consensus areas included risk factors (advanced age, obesity, pre-existing respiratory disease, certain anesthetic agents), diagnosis via continuous pulse oximetry and capnography, and the need for a reversal agent that does not compromise analgesia. A statement on low-dose naloxone infusion did not achieve consensus.

Conclusions: This study establishes expert consensus with a consensus threshold of ≥70% agreement on a clinically applicable definition of PORD, its risk factors, diagnostic criteria, and management principles. The findings provide a framework for standardizing research, guiding perioperative monitoring, and informing preventive strategies, while highlighting the urgent need for targeted reversal agents.