Evaluation of early postoperative intravenous opioid rescue as a novel quality measure in patients who receive thoracic epidural analgesia: a retrospective cohort analysis and prospective performance improvement intervention

Abstract

Background: In this study, we explored the utility of intravenous opioid rescue analgesia in the post anesthesia care unit (PACU-OpResc) as a single marker of thoracic epidural analgesia (TEA) failure and evaluated the resource implications and quality improvement applications of this measure.

Methods: We performed a retrospective analysis of all TEA placements over a three-year period at a single academic medical center in Boston, Massachusetts. The study exposure was PACU-OpResc. Primary outcome was PACU length of stay (LOS). Secondary outcomes included reasons for delayed PACU discharge and intraoperative hypotension. The analyses were adjusted for confounding variables including patient comorbidities, surgical complexity, intraoperative intravenous opioids, chronic opioid use and local anesthetic bolus through TEA catheter. Post analysis chart review was conducted to determine the positive predictive value (PPV) of PACU-OpResc for inadequate TEA. As a first Plan-Do-Study-Act cycle, we then introduced a checkbox for documentation of a sensory level check after TEA placement. Post implementation data was collected for 7 months.

Results: PACU-OpResc was required by 211 (22.1%) patients who received preoperative TEA, was associated with longer PACU LOS (incidence rate ratio 1.20, 95% CI:1.07-1.34, p = 0.001) and delayed discharge due to inadequate pain control (odds ratio 5.15, 95% CI 3.51-7.57, p < 0.001). PACU-OpResc had a PPV of 76.3 and 60.4% for re-evaluation and manipulation of the TEA catheter in PACU, respectively. Following implementation of a checkbox, average monthly compliance with documented sensory level check after TEA placement was noted to be 39.7%. During this time, a reduction of 8.2% in the rate of PACU-OpResc was observed.

Conclusions: This study demonstrates that PACU-OpResc can be used as a quality assurance measure or surrogate for TEA efficacy, to track performance and monitor innovation efforts aimed at improving analgesia, such as our intervention to facilitate sensory level checks and reduced PACU-OpResc.

Trial registration: not applicable.

Keywords: Efficiency metrics; Perioperative analgesia; Quality improvement; Regional anesthesia; Thoracic epidural analgesia.

Fig. 1

Study flow diagram: Flow diagram of the retrospective analysis of Thoracic Epidural Placements over a three-year period (Phase 1). Outcomes of this study were used to plan the performance improvement study (Phase 2), where pre and post intervention monthly rates of PACU-OpResc were compared

Fig. 2

Monthly Rate of Thoracic Epidurals with Documented Sensory Level Check. Percentage of Thoracic Epidurals with documented sensory level check following implementation of discreate SLC documentation field in the electronic procedure note. Data presented as % [SLC] /[Total TEA placements] per month

Fig. 3

Phased process control chart of monthly PACU-OpResc. Phased statistical process control chart (p-chart) of PACU-OpResc as a proportion of monthly TEA. Middle horizontal line reflects the weighted average PACU-OpResc rate before (22.2%) and after (13.9%) implementing SLC documentation. Upper and lower horizontal lines reflect the upper and lower 3σ control limits for each month, respectively. Vertical line marks the implementation of SLC documentation (May 2019). Sample size (TEA placements) was insufficient to determine the lower control limit during April 2018 and January 2019, therefore the zero-PACU-OpResc rate in these months is not considered to be “special cause”. PACU: Post Anesthesia Care unit; PACU-OpResc: Intravenous opioid rescue analgesia in the post-anesthesia care unit; SLC: Sensory level check; TEA: Thoracic Epidural Analgesia