In this study, we found exposure to PACU-OpResc to be significantly associated with prolonged PACU length of stay and delayed PACU discharge. We then demonstrated the utilization of this metric in a quality improvement intervention focusing on TEA catheter placement verification.
Thoracic epidural analgesia is a widely used modality for intra/post-operative pain management in major abdominal and thoracic surgeries, recommended by enhanced recovery after surgery (ERAS) protocols for several surgical disciplines.(20–22) Thus, when offered to patients preoperatively, TEA is often presented as a superior modality to IV analgesia that may contribute to faster recovery, better overall experience and perhaps improved outcome. Our findings imply that for a substantial number of patients, inadequate TEA with PACU-OpResc requirement may hinder this process.
Phase 1: Patient Centered Measure for Thoracic Epidural Analgesia Effectiveness
The primary outcome of this study was chosen to reflect the effect of inadequate TEA on resource allocation. Taking into account that Inadequate pain management is a known factor for increased PACU length of stay(23), we theorized that exposure to PACU-OpResc, as a surrogate for inadequate TEA will prolong PACU length of stay. Indeed, our analysis, adjusted for patient and procedure specific confounders, showed that patients who required PACU-OpResc had significantly longer PACU length of stay and their discharge was more frequently delayed due to inadequate pain management. We suggest that investing resources to verify adequate TEA and catheter placement, even though it may delay the OR workflow, may prove to be cost-effective, and reduce PACU length of stay for these patients.
The definition of failed epidural analgesia varies substantially between authors and ranges from specific criteria such as failure to place a catheter at 1st attempt(8) to broader definitions which include ‘’documented inability to locate the epidural space during insertion or complete lack of any surgical site sensory block following epidural bolus”(13) or “any condition during the course of treatment that requires epidural catheter replacement or the addition of another major treatment modality such as IV patient- controlled analgesia”.(7) Irrespective of nomenclature, failure to achieve adequate analgesia requiring rescue analgesic management in the immediate post-operative phase represents an undesirable outcome for the patient and could be considered a marker of TEA failure. In planning this study and intervention, we focused on establishing a framework for a learning environment that would prospectively enable feedback on the effectiveness of staged quality improvement interventions. We chose to focus on PACU-OpResc as pragmatic measure that represents the overall patient experience, regardless of the reason for inadequate TEA.
The rate of PACU-OpResc of 22.1% in our center lies within the previously reported range of TEA failure rates and supports PACU-OpResc as a surrogate measure for inadequate TEA. We further demonstrated good positive predictive value of PACU-OpResc for documented evaluation by the APS team and documented interventions to improve TEA effectiveness in PACU. Evaluation of patients with TEA and interventions may be performed by anesthesiology teams in the PACU or the OR and may not always be documented. We, therefore, assume that our calculated PPV is an underestimation of the ability of PACU-OpResc to identify cases of inadequate TEA.
Phase 2: Intervention Study
While mapping and assessing the TEA placement process for potential points of intervention, we noted that on perceived successful placement of a TEA and following the administration of a standardized test dose, a sensory level check (SLC) was not being consistently performed. Furthermore, if a SLC was performed it was not documented due to the lack of a discrete documentation element in the electronic procedure note. We focused on the SLC documentation as a first PDSA cycle, through which we could gain knowledge both on the TEA process and PACU-OpResc as its measure. Our aim was to assess firstly, compliance with SLC documentation immediately after TEA placement and secondly, the impact of SLC documentation on TEA failure rates.
Our chosen intervention formally targeted catheter location verification. However, in our center, where one team places the TEA and another uses it in the OR, we theorized that taking a patient to the OR with a proven-to-be-working TEA, may incentivize physicians to utilize it better, and relay more TEAs for intra-operative analgesia. Larsson et al(15) demonstrated that adequate sensory level after a local anesthetic bolus can be achieved in 35% of the patients within 5–6 minutes, and in 99% of the patients within 15 minutes. As we were aware of the time constrains and pressure to quickly take patients to the OR, we deliberately did not mandate or actively promote conducting a sensory level check throughout the intervention period. Thus, we believe that a level check was conducted after placement only when OR workflow permitted it, and that our compliance rate of 39.7% with level checking and documenting adequate sensory level after TEA placement, reflects an inherent ability and resources to do so in our center. We speculate that conducting a level check as well as the ability to document it have reduced PACU-OpResc by allowing for timely manipulation of improperly placed catheters and by encouraging the intraoperative blousing and infusion through TEA by the OR team. We could neither identify alternative explanations or interventions aimed at reducing opioid administration in our PACU nor detect a significant change in our anesthesia faculty, technique or equipment during our implementation period. Trends in current anesthesia practice aimed at reducing perioperative opioid administration(24–26) may have influenced our findings. However, this would explain a gradual reduction in opioid dosing rather than a significant drop in PACU-OpResc.
Limitations
This study is a single center retrospective analysis followed by an intervention which despite being effective in our center may not be applicable elsewhere. However, we present a pragmatic, feasible metric for TEA effectiveness which may be a measure for local standard of care and management of TEAs. There are, however, biases for using this measure. Inadequate TEA may be overestimated by including patients receiving opioids as part of their post-operative anesthetic plan due to known dependency, or for whom a clinical decision to not use the TEA was made. We attempted to control for this confounder by adjusting our analysis for chronic opioid use. Hypotension, a common reason to discontinue the TEA infusion was included in our secondary outcomes and did not differ between the two study groups.
Underestimation of inadequate TEA using PACU-OpResc may occur when the epidural catheter was replaced, manipulated or bolused before a patient received IV opioids, or cases in which adequate analgesia was achieved with non-opioid supplement analgesics. Nevertheless, this adds strength to PACU-OpResc as a measure of the overall process and management of TEAs, also reflecting the timely identification and correction of inadequate TEA to provide better patient care. Our results are further limited by their retrospective nature and by the possibility that factors other than our intervention are responsible for this result, despite our best efforts to eliminate such historical bias.