///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

Pro Re Nata or “Per Registered Nurse”? Observed Clinical Variation in PRN Analgesic Administration and Implications for Pain Research

Abstract Number: F3D-425
Abstract Type: Original Research

LeAnn Lam BS1 ; Mallika S. Thampy MD2; Sarah S. Osmundson MD3; Michael G. Richardson MD4

BACKGROUND: Inpatient PRN opioid analgesics (OAs) are intended to be administered “as needed” by the patient, not at standard time intervals. Total PRN opioid usage is the primary outcome chosen to assess efficacy of interventions in many post-operative pain studies, under the assumption that analgesics are administered upon patient request. Yet, non-patient specific factors clearly influence PRN opioid administration [1,2], including nurse administration behaviors.[3] We sought to determine whether post-cesarean delivery (CD) patients receive PRN OA primarily when they request them, when offered by their nurse, or a combination of both, and whether this affects total OA and ibuprofen use.

METHODS: Women who underwent uncomplicated CD were surveyed on post-op day 1 regarding inpatient analgesic use, including whether they received OAs when they requested, when their nurse offered them unsolicited, or both. Women were also asked whether they were receiving enough analgesic medication and whether they were intentionally limiting OA use. Total inpatient opioid MME and ibuprofen used between 24 and 48 hours post-CD were compared. Our institution’s inpatient post-CD analgesic order set contains scheduled ibuprofen 600mg every 6 hours and “as needed” PRN opioid (hydrocodone 5mg or oxycodone 5mg) every 4 hours.

RESULTS: From 8/2018 to 1/2019, 193 women gave informed consent and completed the survey. Only 14 (7.3%) reported receiving OAs upon requesting them. 97 (50.3%) primarily received OAs when their nurse offered, and 82 (43.4%) reported that OAs were given both on request and when offered. Inpatient opioid use was lower among women who were offered OAs by a nurse (17.5 MME [IQR 5-30]) vs women who requested OAs (22.5 MME [15-30]) or women who both requested and were offered OAs (25.0 MME [10-35]), p=0.007. There were no differences in ibuprofen use between the three groups (2400mg [2400-2400] vs 2400mg [2400-2400] vs 2400mg [1800-2400]), p=0.92 and no differences in reported self-limiting of OAs or perception that patients were not receiving enough OAs.

CONCLUSION: Only a small proportion of women who were prescribed PRN OAs during inpatient hospitalization for CD received OA “as needed” by request. Our findings suggest inpatient medications written as PRN have variable nurse interpretations and may not necessarily reflect true pain needs as previously assumed. Lowest inpatient OA use in the nurse-offered group deserves greater scrutiny. Not requesting and nurse offering may simply result from low patient OA need or preference. Nonetheless, pain research that relies on PRN opioid use as the primary outcome should carefully define PRN orders and ensure consistent clinical interpretation to reduce confounding due to variation in nursing interpretation and executing PRN orders.


1) Badreldin et al. Am J Obstet Gynecol 2018;219:608

2) Herzig et al. J Hosp Med 2014;9:73

3) Taylor et al. Orthoped Nurs 2017;36:392

SOAP 2019