Analgesia After Cesarean Delivery in the United States 2008–2018: A Retrospective Cohort Study
Authors: Reed Sydney E. , Tan Hon Sen , Fuller Matthew E. , Krishnamoorthy Vijay , Ohnuma Tetsu , Raghunathan Karthik , Habib Ashraf S. 
Published: May 2021

BACKGROUND:
Optimizing analgesia after cesarean delivery is a priority and requires balancing adequate pain relief with the risk of analgesics-associated adverse effects. Current recommendations are for use of a multimodal, opioid-sparing analgesic regimen that includes neuraxial morphine combined with scheduled nonsteroidal anti-inflammatory drugs (NSAIDs) and scheduled acetaminophen. Furthermore, recent studies recommend scheduled acetaminophen with as-needed opioids in lieu of acetaminophen-opioid combination drugs to reduce opioid consumption and optimize analgesia. However, the extent of utilization of this recommended regimen in the United States is unclear. We therefore performed this retrospective study to evaluate postoperative analgesic regimens utilized after cesarean delivery under neuraxial anesthesia, examine variability across institutions, evaluate changes over time in postoperative analgesic practice, and examine factors associated with the use of neuraxial morphine and of multimodal analgesia.

METHODS:
This retrospective cohort study was approved by the Duke University Institutional Review Board. Parturients who underwent cesarean delivery under neuraxial anesthesia from 2008 to 2018 were included. Data were extracted from a nationwide inpatient administrative-financial database (Premier Inc, Charlotte, NC) and included parturient characteristics, comorbidities, hospital characteristics, and charges for administered medications. The primary outcome was the postoperative analgesic regimen utilized during hospitalization, including utilization of neuraxial morphine and of multimodal analgesia for postoperative pain control. We also examined the factors associated with the use of neuraxial morphine and of the multimodal regimen incorporating neuraxial morphine, NSAIDs, and acetaminophen.

RESULTS:
Data from 804,752 parturients were analyzed. Of this cohort, 75.8% received neuraxial morphine, 93.2% received NSAIDs, 28.4% received acetaminophen, and 81.3% received acetaminophen-opioid combination drugs. Only 6.1% received the currently recommended regimen of neuraxial morphine with NSAIDs and acetaminophen, with this percentage increasing from 1.3% in 2008 to 15.0% in 2018. On the other hand, 58.9% received neuraxial morphine, NSAIDs, and an acetaminophen-opioid combination drug, with this regimen being utilized in 57.0% of cases in 2008 and 58.1% in 2018. The hospital in which the patient was treated accounted for 54.7% of the variation in receipt of neuraxial morphine and 41.2% in the variation in receipt of multimodal analgesia with neuraxial morphine, NSAIDs, and acetaminophen, with this variability in receipt of neuraxial morphine and of multimodal analgesia being largely independent of patient characteristics.

CONCLUSIONS:
Relatively few parturients received the currently recommended multimodal analgesic regimen of neuraxial morphine with NSAIDs and acetaminophen after cesarean delivery. Additionally, the majority received acetaminophen-opioid combination drugs rather than plain acetaminophen. Further studies should investigate the implications for patient outcomes.