ABSTRACT TITLE: Near-OR Perioperative Interventions to Decrease Hospital Length

Transcription

1 ABSTRACT NUMBER: ABSTRACT TITLE: Near-OR Perioperative Interventions to Decrease Hospital Length of Stay AUTHORS: Mark J. Lenart, MD Vanderbilt University 1301 Medical Center Drive Nashville, TN Randall J. Malchow, MD Vanderbilt University 1301 Medical Center Drive Nashville, TN Rajnish K. Gupta, MD Vanderbilt University 1301 Medical Center Drive Nashville, TN Kam Wong, MD Vanderbilt University 1301 Medical Center Drive Nashville, TN POMS 22 nd Annual Conference Reno, Nevada, U.S.A April 29 to May 2,

2 Near-OR Perioperative Interventions to Decrease Hospital Length of Stay Reductions in Hospital Stay Using Single Shot and Continuous Peripheral Nerve Blocks for Orthopedic Surgery An Initial Evaluation Mark J Lenart, MD Randall J Malchow, MD Rajnish K Gupta, MD Kam Wong, MD Damon Michaels, B.S., CCRP Research Advisor Vanderbilt University Medical Center Department of Anesthesiology 2

3 1.0 ABSTRACT Introduction: The number of orthopedic surgical cases has increased significantly over the last several decades. Pain management that can optimize patient care while minimizing hospital length of stay (LOS) can have a significant impact on reducing hospital costs as well as increasing patient satisfaction. Previous studies have shown the benefits of regional anesthesia in meeting these goals. Methods: We retrospectively analyzed the medical records of 507 patients at an academic teaching Level 1 trauma center who underwent orthopedic procedures and major lower extremity amputations managed with traditional postoperative pain management (IV PCA and oral narcotics), single injection peripheral nerve block (PNB), and continuous peripheral nerve block (CPNB) in order to determine the impact different pain modalities might have on hospital length of stay. Results: When compared to traditional pain control methods, PNB s as well as CPNB s, were observed to decrease the length of hospital stay for patients admitted for most major orthopedic surgeries except total knee arthroplasty (TKA). Discussion: Our retrospective case review showed that most orthopedic surgery patients receiving PNB or CPNB had shorter length of stay when compared to those receiving no block and traditional pain management. TKA patients showed no difference in length of stay whether they received no block, PNB, or CPNB. 3

4 2.0 INTRODUCTION Peripheral Nerve Blocks (PNB) deliver local anesthetics near a nerve or nerve plexus for pain relief. This modality of pain management has received recognition because of its superior analgesia with less opiate requirements along with fewer side effects. Some studies have shown that regional analgesia reduced hospital admission rates from 17% without a block to 4% with a peripheral nerve block and helped cut hospital costs by 12%. 1 In a large meta-analysis study, continuous peripheral nerve block analgesia, regardless of catheter location, provided superior postoperative analgesia and fewer opioid-related side effects when compared with opioid analgesia alone. 2 Hebl et al found similar success with major orthopedic surgery performed at the Mayo Clinic. 3,4 Single injection femoral nerve block has been demonstrated to reduce hospital stay in patients undergoing total knee replacement when compared to controls. 5 A study of Total Joint Regional Anesthesia (TJRA) Clinical Pathway at Mayo Clinic, when combined with minimally invasive surgery (MIS) led to average cost reductions of greater than $4500 per patient. 6 Based on these results, we speculated that CPNB analgesia has the potential of producing shorter hospital length of stay for patients, leading to lower associated costs for the hospital. The result of this study could further justify support for the expanded role of advanced regional anesthesia and multimodal analgesia across the country. 4

5 3.0 METHODS A retrospective chart analysis of 507 different orthopedic procedures performed with traditional postoperative pain management (IV PCA and oral narcotics), single injection peripheral nerve block (PNB), and CPNB was performed. Specifically, five groups of operations organized by Current Procedural Terminology (CPT) codes were investigated as follows: Group 1: shoulder fractures and total shoulder arthroplasty (TSA). Group 2: total elbow arthroplasty (TEA). Group 3: total knee arthroplasty (TKA). Group 4: major lower extremity amputations (AKA, BKA). Group 5: talus and calcaneal fractures. Inclusion: Patients 18 years of age Inpatients Above and below knee amputations Adult orthopedic surgery patients who have traditional post operative pain management (IV PCA + PO narcotics) Adult orthopedic surgery patients who have their pain managed with PNB + multimodal analgesics 5

6 Adult orthopedic surgery patients who have their pain managed with CPNB + multimodal analgesics Patients with extremity trauma Patients who have had a total knee arthroplasty (TKA) Patients who have had a humeral fracture Patients who have had a calcaneal fracture Patients who have had tibia-fibula fractures Patients who have had a talus fracture Patients who have had an elbow arthroplasty Patients who have had a total shoulder arthroplasty (TSA) Exclusion: Patients < 18 years of age Burn patients Patients with intracranial trauma Patients with spinal trauma Patients with thoracic trauma Patients with abdominal trauma The data were collected from November 1, 2008 to November 1, 2009 at a single academic institution. Operations were performed at a Level 1 trauma center. 6

7 The measured variables included length of hospital stay, mode of analgesic relief, and age of the patient. Length of hospital stay began on the day of surgery. The mode of analgesic relief was defined as no peripheral block, PNB, and CPNB. The Institutional Review Board (IRB) approved the retrospective chart review prior to initiation of the project. All patient-identifying data were removed prior to data analysis so that patient confidentiality was preserved. Only de-identified data were used as part of the research team s effort. Patient and surgery characteristics were tabulated by nerve block type. Categorical variables were represented as percentages and counts while continuous variables were summarized with quartiles (25th, 50th = median, 75th), range, mean, and standard deviation. Differences between the nerve block groups were determined by performing Χ 2 test or the Kruskal-Wallis test. Box plots were also created to summarize the relationship between type of nerve block, CPT code group and length of stay. The box was constructed by plotting the median and the 25th and 75th quartiles and the whiskers were defined as 1.5 interquartile range (IQR, difference between 75th and 25th quartiles). The y-axis was truncated at 30 days to ensure adequate visualization of the distributions of length of stay. Median length of stay values for each nerve block type were plotted by CPT code group and labeled with colored triangles positioned to the left of the center of each box plot. All analyses were performed in R version

8 4.0 RESULTS Table 1 summarizes the patient and surgery characteristics of the 507 patients that met the eligibility criteria of this retrospective chart review. The TKA group was the largest with 284 patients, or 56% of the data. The remainder of the patients was comprised of shoulder replacement/fractures 12%, elbow replacements 3.2%, major lower extremity amputations 14.2%, and talus and calcaneal fractures 14.6%. The median age for patients without a block was 49 years old compared to 62 years old for patients with single or continuous blocks (p<0.0001). Single injection nerve blocks (PNB) were utilized most frequently and resulted in a 3-day median length of stay. Statistically significant differences (in length of stay) were noted among each of the variables when stratified by nerve block type (e.g., single nerve blocks were commonly used with knee replacement surgeries, while continuous catheters were used during shoulder fracture/replacement surgeries). Median length of stay estimates were 3 days regardless of block type, but the distributions of these estimates differed. For example, the 75th quartiles for those patients with a single or continuous catheter were 4 and 3 days, respectively, while it was 8 days for those without a nerve block. Figure 1 is a box and whisker plot illustrating the length of stay among the five surgical CPT code groups. The colored triangles represent the median value for each group. Statistically significant differences in length of stay were not observed among patients undergoing TKA surgery, regardless of the analgesic regimen of choice. For each of the other four CPT code groups, subjects without a nerve block remained in the hospital longer than those with a continuous nerve block catheter. No consistent relationship was 8

9 observed between single injection PNBs and length of stay across all CPT groups. LOS for shoulder surgery was decreased with either a PNB or CPNB, compared to no block. For major lower extremity amputations, CPNB demonstrated significant LOS reduction when compared to either no block or PNB. CPNB patients had shorter LOS in four out of the five CPT code groups studied. 5.0 DISCUSSION Peripheral nerve blocks decrease the length of hospital stay for patients admitted for most major orthopedic surgeries except TKA. Single injection nerve blocks allowed for shorter length of stay when compared to traditional oral narcotic pain control, while CPNB produced the shortest length of stay overall. All patient groups were demographically similar in all variables except for age. As seen in Table 1, the No Block group actually had the lowest median age of all three groups. Our data showed that the nerve block patient groups, which were statistically older, had shorter length of stay than this younger group. Since it would be expected that younger patients would recover more quickly from major surgery than older patients, this demographic difference suggests that the observed difference in length of stay may be attributed to the single and continuous nerve blocks rather than any difference in age. The statistically insignificant difference in length of stay seen in TKA patients may be due to factors other than pain control. This was also observed and reported earlier by Salinas. 7 Discharge criteria for patients receiving total joint replacements are often governed by established protocols that operate largely independently of pain 9

10 management. Although CPNB produced shorter length of stay with major lower extremity amputations, this difference was not observed with PNBs. Major lower extremity amputations are most commonly performed in diabetic patients with vascular insufficiency, often in the setting of distal infections. These comorbidities possibly influence the short-term length of their postoperative course greater than their immediate pain control. Future prospective double-blind, randomized controlled trials that reduce the possibility of selection bias and eliminate the variability in patient care protocols would be necessary to establish a more clear cause and effect relationship between PNB, CPNB, and traditional oral and IV opioid therapy and length of hospital stay. This study demonstrated that CPNB has significant potential to decrease length of stay for major orthopedic surgery and major lower extremity at a major Level 1 trauma academic hospital. 10

11 Figure 1 Red Triangle No block; Black Triangle PNB; Blue Triangle - CPNB 11

12 6.0 References: 1. Williams BA, Kentor ML, et al. The economics of nerve block pain management after anterior cruciate ligament reconstruction: significant hospital cost savings via associated PACU bypass and same-day discharge. Anesthesiology. 2004; 100: Richman, JM. Does continuous peripheral nerve block provide superior pain control to opioids? A meta-analysis. Anesth Analg. 2006; 102: Hebl J, Dilger J. A Pre-emptive Multimodal Pathway Featuring Peripheral Nerve Block Improves Perioperative Outcomes After Major Orthopedic surgery. Regional Anesthesia and Pain Medicine. 2008; 33(6): Duncan CM, Long KH, Warner DO, Hebl JR. The Economic Implications of a Multimodal Analgesia Regimen for Patients Undergoing Major Orthopedic Surgery. Regional Anesthesia and Pain Medicine. 2009; 34(4): Wang H, Boctor B, Verner J. The Effect of Single-Injection Femoral Nerve Block on Rehabilitation and Length of Hospital Stay after Total Knee Replacement. Regional Anesthesia and Pain Medicine. 2002; 27(2): Duncan CM, Long KH, Warner DO, Pagnano MW, Hebl JR. The Economic Implications of a Multimodal Analgesic Regimen Combined with Minimally Invasive Orthopedic Surgery: A Comparative Cost Study. J Anesthe Clinic Res. 2010; 1(1). 12

13 7. Salinas FV, Liu SS, Mulroy MF. The Effect of Single-Injection Femoral Nerve Block Versus Continuous Femoral Nerve Block After Total Knee Arthroplasty on Hospital Length of Stay and Long-Term Functional Recovery Within an Established Clinical Pathway. Anesth Analg. 2006; 102: