Identification of serious iatrogenic opioid-related adverse events in hospitalized patients

Purpose: This study was performed in order to document serious respiratory or central nervous system adverse events in patients receiving opioid analgesics in the hospital. Risk factors for adverse events were described in order to identify potential medication safety opportunities.

Methods: A retrospective chart review of inpatients receiving naloxone for opioid reversal was conducted during a three month period in 2011. Patients were included if they experienced CNS or respiratory depression reversible with naloxone with adequate supporting documentation from medical or nursing notes. We excluded patients who were less than 18 years of age and patients who received naloxone for non-iatrogenic overdose indications.

Results: There were 155 patients identified who received naloxone during the study period. After excluding those who received naloxone for reversal immediately following surgery, and non-iatrogenic overdose indications, there were 49 patients who met our inclusion criteria. Postoperative patients comprised 58% of the population who required naloxone for reversal. The ADE met Naranjo criteria for a probable or definite adverse drug reaction in 76% of cases; the remaining 24% were considered possible adverse drug reactions. Transfer to a higher level of care was required in 35% of cases and intubation in 8%. Sleep apnea was a risk factor in 24%, and renal dysfunction was a risk factor in 14% of those who experienced events related to morphine. Inadequate monitoring of level of sedation was noted in 54% of the patients who experienced events on PCA.

Conclusions: Serious opioid adverse events requiring naloxone administration were commonly identified through this systematic review. We identified several key safety improvement opportunities that hospitals should implement in order to reduce risk of harm in this population.