Essential monitoring strategies to detect clinically significant drug- induced respiratory depression in the postoperative period
Anesthesia Patient Safety Foundation (APSF)

These Conclusions and Recommendations are intended to facilitate detection of clinically significant drug-induced respiratory depression in non-ambulatory adult patients receiving parenteral opioids for management of acute postoperative pain while being cared for in a healthcare facility.

Conclusions and Recommendations

  1. Future technology developments may improve the ability to more effectively utilize continuous electronic monitoring of oxygenation and ventilation in the postoperative period. However, maintaining the status quo while awaiting newer technology is not acceptable.
  2. Intermittent “spot checks” of oxygenation (pulse oximetry) and ventilation (nursing assessment) are not adequate for reliably recognizing clinically significant evolving drug-induced respiratory depression in the postoperative period.
  3. Continuous electronic monitoring of oxygenation and ventilation should be available and considered for all patients and would reduce the likelihood of unrecognized clinically significant opioid-induced depression of ventilation in the postoperative period.
  4. Continuous electronic monitoring should complement and not replace traditional intermittent nursing assessment and vigilance.
  5. All patients should have oxygenation monitored by continuous pulse oximetry (see Observation 1).
  6. Capnography or other monitoring modalities that measure the adequacy of ventilation and airflow is indicated when supplemental oxygen is needed to maintain acceptable oxygen saturations.
  7. Although careful preoperative screening for conditions that may be associated with an increased risk of postoperative respiratory insufficiency (obstructive sleep apnea, obesity, chronic opioid therapy) is recommended and may be part of a graduated continuous monitoring adoption plan, applying electronic monitoring selectively based upon perceived increased risk is likely to miss respiratory depression in patients without risk factors (see Observation 2).
  8. Monitoring continuous oxygenation and ventilation from a central location (telemetry or comparable technologies) is desirable. This information needs to be reliably transmitted to the healthcare professional caring for the patient at the bedside.
  9. Structured assessment of the level of sedation/consciousness is a critical component of the nurse’s routine postoperative patient assessment for detecting respiratory depression.
  10. Nurse and physician education is critical to ensure an (1) understanding of the physiology and pharmacology of drug-induced respiratory depression, (2) the potential obscuring impact of patient arousal on respiratory depression during clinical assessment and (3) the interference of supplemental oxygen administration on detection of progressive hypoventilation when pulse oximetry is the only continuous electronic monitor.
  11. Continuous electronic monitoring systems should integrate multiple physiologic parameters to identify clinically significant changes earlier and more reliably.
  12. Threshold-based alarm limits on individual physiologic parameters may result in the caregiver failing to recognize early signs of progressive hypoventilation by either being too sensitive (excess false alarms) or insufficiently sensitive.
  13. Impediments to continuous electronic monitoring of oxygenation and ventilation in the postoperative period are multifaceted. Among attendees categorizing their responses to the written questions as Caregivers orCorporate the two greatest impediments were (1) initial investment cost in instituting existing technology and (2) failure of caregivers to recognize (inadequate education) the true risk of drug-induced respiratory depression.


  1. APSF is aware of hospital systems that have adopted continuous capnography in combination with pulse oximetry, or in lieu of pulse oximetry.
  2. APSF acknowledges that, due to limited healthcare resources, implementation of these conclusions and recommendations may be part of a graduated continuous electronic monitoring adoption plan. However, institution of these conclusions and recommendations must not be delayed while awaiting newer technology.
  3. APSF advocates increased public and private investment in research to develop monitors with high reliability and ease of use.
  4. APSF strongly encourages research and continuous quality improvement (CQI) to evaluate the impact and cost effectiveness of these Conclusions and Recommendations.
  5. APSF believes that multimodal analgesia techniques need to be used more often to decrease the use of opioids alone for postoperative pain management.