The prevalence of and risk factors for adverse events in children receiving patient-controlled analgesia by proxy or patient-controlled analgesia after surgery

Anesth Analg. 2008 Jul;107(1):70-5. doi: 10.1213/ane.0b013e318172fa9e.


Background: Recent reports emphasize the risks associated with patient-controlled analgesia by proxy (PCA-P), yet data regarding such risks in children remain sparse. We compared the prevalence of clinically significant adverse events in children receiving PCA-P versus PCA, and examined factors that place children at increased risk.

Methods: The records were reviewed of opioid-naïve children, ages birth to 18 yr, who received PCA or PCA-P after surgery. Data included demographics, comorbidities, perioperative information, pain, sedation, and respiratory assessments, oxygen saturation, analgesics, adverse outcomes, and interventions.

Results: This study included 145 children who received PCA-P and 157 PCA. The PCA-P group was younger and had more comorbidities (P < 0.05). Opioid orders were similar, but pain scores and opioid dosages were lower, and fewer children received diazepam in the PCA-P group (P < 0.05). Clinically significant adverse events (i.e., those requiring intervention) occurred in 22% and 24% of patients in the PCA-P and PCA groups, respectively; however, more children in the PCA group had "threshold events" (minor intervention) and more in the PCA-P group had "rescue events" (opioid reversal or escalation of level of care). Respiratory events occurred earlier in the PCA-P group (P < 0.05). Factors associated with adverse events included orthopedic surgery, cognitive impairment, respiratory comorbidity, use of continuous basal opioid infusion, use of diazepam, and larger opioid doses on days 1, 2, and 3. Yet, cognitive impairment and opioid dose on day 1 were the only factors independently predictive of these events.

Conclusions: This study found that although a significant number of children receiving PCA and PCA-P experienced adverse events, there was no difference in the prevalence between groups. The PCA-P group was at greater risk for events requiring rescue interventions, perhaps due to the prevalence of underlying comorbidities. These findings emphasize the need for vigilant monitoring to facilitate early recognition and timely intervention of respiratory depression.

MeSH terms

  • Adolescent
  • Analgesia, Patient-Controlled / adverse effects*
  • Analgesics, Opioid / administration & dosage*
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Oximetry
  • Pain, Postoperative / prevention & control*
  • Prevalence
  • Proxy*
  • Respiration / drug effects
  • Retrospective Studies
  • Risk Factors


  • Analgesics, Opioid