The effect of intravenous opioid patient-controlled analgesia with and without background infusion on respiratory depression: A meta-analysis

Abstract

Background: Although the addition of a background infusion for intravenous patient-controlled analgesia (IV-PCA) has been identified as a risk factor for the development of respiratory depression, this has not clearly been examined in a systematic fashion. The authors undertook a systematic review and meta-analysis of available randomized controlled trials (RCTs) to examine whether the addition of a background or continuous infusion to an IV-PCA regimen would be associated with an increased risk of respiratory depression.Methods: Studies were identified by searching the National Library of Medicine’s PubMed database (1966 to November 30, 2008). Inclusion criteria were a clearly defined analgesic technique of demand-only IV-PCA versus IV-PCA utilizing both a demand dose and background infusion, opioid medication used, and randomized trials. Data were abstracted and analyzed with the RevMan 4.2.7 (The Cochrane Collaboration, 2004).Results: The search yielded 687 abstracts from which the original articles were obtained and data abstracted with a total of 14 articles analyzed. There were 402 subjects in the continuous IV-PCA with demand group versus the 394 subjects in the demand-only IV-PCA group. Addition of a background infusion to the demand dose for IV-PCA with opioids was associated with a significant increased risk for respiratory depression (odds ratio [OR] = 4.68, 95% confidence interval [CI]: 1.20-18.21). Subgroup analysis revealed that this increased risk was seen in adult but not in pediatric patients.Conclusions: Our meta-analysis indicates that the addition of a continuous or background infusion to the demand dose for IV-PCA is associated with a higher incidence of respiratory events than demand IV-PCA alone in adult but not in pediatric patients; however, our overall results should be interpreted with caution due to the relatively small sample size and the wide range of definitions for respiratory depression in studies examined.

Opioid patient controlled analgesia use during the initial experience with the IMPROVE PCA trial: A phase III analgesic trial for hospitalized sickle cell patients with painful episodes

“…This initial subject cohort documented the feasibility of the study protocol and the PCA dosing guidelines, but demonstrated the continued challenges of recruiting SCD subjects to an in-patient interventional clinical trial. As seen in previous opioid PCA studies, the use of substantial PCA demand doses with modest continuous infusions (HDLI) in adult subjects in this study resulted in larger total cumulative opioid utilizations than a strategy relying predominantly on continuous higher opioid infusions with small demand doses (LDHI) [8]. However, similar paradigms in children showed little difference reflecting a smaller use of available demand doses [13].…”

“…Current PCA strategies for severe pain typically include an opioid given by continuous infusion in addition to the PCA demand doses, but the addition of continuous opioid infusions has often been associated with increased opioid-related adverse effects [8],[9],[10]. To provide an evidence base for the clinical use of opioid PCA for sickle cell acute pain management, it is crucial to compare different PCA dosing approaches to determine their safety and efficacy.…”

The scientific evidence for acute pain treatment

“…This lower level yet very valuable evidence has only recently been confirmed in a meta-analysis which found a higher incidence of respiratory events with the routine use of background infusions in adult but not pediatric patients [40 ].…”

Acute Pain Management in Hospitalized Adult Patients with Opioid Dependence: A Narrative Review and Guide for Clinicians

“…If a patient cannot tolerate oral medications, PCA can provide continuous infusion of medication to provide basal analgesia, though the risk of oversedation and respiratory depression is increased. 28 For our clinical example, we recommend increasing the preadmission TDD of opioids (180 mg morphine equivalents) by 25% (225 mg) and administering as morphine 75 mg sustained-release every 8 hours to provide baseline analgesia and prevent withdrawal symptoms. The acute pain can be managed by initiating morphine PCA without continu- ous infusion at 0.5 mg bolus every 8 minutes as needed for breakthrough pain or oral morphine 30 mg immediate-release tablets every 3 hours as needed for pain.…”