Quantitative Analysis of Anesthesia Utilization in Ambulatory Hand Surgery

Abstract

Background

Though evidence demonstrating benefits of local anesthetic continues to compound, a consensus among surgeons regarding optimal anesthetic modality has not been reached. General and regional anesthetic may still be preferred for patient anxiety, concomitant procedures, increased complexity, or poor patient pain tolerance. Therefore, the primary purpose of this study was to analyze trends in anesthetic utilization using a large-scale state healthcare database for common outpatient hand procedures. We hypothesize that over the 10 years between 2010-2019, local anesthetic [including Wide-Awake Local Anesthesia with no Tourniquet (WALANT)] utilization use for common hand procedures has increased, while the use of general and regional anesthesia has decreased.

Methods

A cross-sectional analysis was performed using the Texas Healthcare Information Collection Outpatient Database between 2010-2019. The de-identified data was queried for reported Current Procedure Terminology (CPT) anesthetic and associated procedure codes for the following ambulatory techniques: open carpal tunnel release, endoscopic carpal tunnel release, trigger finger release, De Quervain’s release, partial palmar fasciectomy, and hand mass excision. Anesthetic options included: regional anesthesia (RA), local or WALANT anesthesia (LA), and general anesthesia (GA).

Results

There were 340,117 procedures performed during the study period. 98.14% of patient records reported LA application, while GA and RA only accounted for 0.41% and 1.45%, respectively. No significant growth was found for each form of anesthetic individually [LA: -0.12%, RA: 0.09%, and GA: 0.03%]. However, a significant difference in proportional growth is present when comparing all anesthetics (Figure 1, p<0.001). Commercial/ private insurance was the most common payer regardless of anesthesia type, though Medicaid payment source covered a larger proportion of procedures performed under GA [Medicaid: 2.48%, Medicare: 0.37%, worker’s compensation: 0.12%, commercial/private insurance: 0.20%].

Conclusion

LA was the most utilized modality over the study period, though a significant proportion of usage has shifted back towards RA and GA over time. Commercial/private insurance was the most frequent reimbursement source for all procedures, though Medicaid covered disproportionately more procedures utilizing GA. RA use was noted to be disproportionately higher in mid-sized population centers (2-4 million in population).

Level of Evidence: IV

Introduction

Upper limb and hand surgeries are common procedures in plastic and orthopaedic surgery. Many procedures and most surgical specialties have transitioned to ambulatory surgery over the past two decades because of healthcare insurance influences, Medicare initiatives, advancements in medical technology, improved anesthetic techniques, and physician practice trends. As a result, many hand tendon, nerve, bone, joint, vascular, and other soft tissue procedures are now routinely performed as outpatient surgeries. Tourniquet use during these procedures is frequently employed to minimize blood loss, and historically RA or GA were the preferred anesthetic methods for hand surgery.¹

To further define anesthetic modalities, regional block anesthetic (RA) involves the injection of an anesthetic near a nerve that supplies a specific body region. Common regional anesthetic techniques utilized in hand surgery include the brachial plexus block or axillary block. Conversely, local anesthesia (LA) involves the injection of anesthetic directly into the area of the procedure. In hand surgery, local anesthesia is often utilized for low acuity procedures such as removing a cyst or performing a biopsy. This modality can also be employed in conjunction with sedation or general anesthesia. Finally, general anesthesia (GA) involves the administration of medication that causes the patient to become unconscious and unable to feel pain during surgery. In hand surgery, general anesthesia may be advantageous for complex procedures, such as tendon repairs or joint replacements.

In a 1987 survey study of American Society for Surgery of the Hand (ASSH) members, most carpal tunnel release (CTR) procedures utilized regional anesthesia on an outpatient basis.² Now, newer subsequent studies estimate that CTR performed under local anesthesia with monitored anesthetic care (MAC) is the most common practice utilized by hand surgeon society members.^3-5 Conversely, conflicting database studies examining CTR, De Quervain release and trigger finger release indicate a majority of RA and GA usage with a growing trend in LA utilization.^6-7

With the transition of many hand procedures to outpatient surgery, anesthesia trends have also transformed. One such transformation in the past fifteen years has been the implementation of a LA with epinephrine.⁸ This breakthrough has given surgeons another tool to opt for multiple hand operations to transition into the minor procedure room. As a result, this method has gained notoriety due to increased efficiency, convenience, and reduced cost.^9-11 Now, it is estimated that 62% of hand surgery society members incorporate WALANT into their practice.¹²

Research demonstrating the benefits of LA continues to compound, though there remains no consensus regarding an optimal modality. RA and GA may still be preferred in cases of patient anxiety, concomitant procedures, increased complexity, or poor pain tolerance.^13-14 Therefore, the primary purpose of this study was to analyze anesthetic choice in common ambulatory hand procedures using a large-scale healthcare database. We hypothesized that local anesthetic utilization in ambulatory hand surgery has increased. Furthermore, we analyzed anesthetic administration during procedures with respect to patient sex, race, ethnicity, age, primary insurance designation, and patient-reported place of residence (metropolitan, micropolitan, or rural).

Methods

Study Design

This study was exempt from Institutional Review Board (IRB) approval. A study population of 340,117 de-identified outpatient surgical records was obtained from the publicly available Texas Health Care Information Collection (THCIC) database through the Texas Department of State Health Services (TDSHS) for retrospective cross-sectional analysis.¹⁵ The cohort from 2010 to 2019 was selected to avoid any COVID-19 pandemic effects on elective surgery. According to the United States Census Bureau, Texas is the second most populated state with over 29 million documented residents (2019), and represents a diverse ethnic and socioeconomic population. Records were identified through query of the database using Current Procedure Terminology (CPT) codes for the following common ambulatory hand procedures: trigger finger release, De Quervain’s release, endoscopic carpal tunnel release, open carpal tunnel release, hand mass excision, and partial palmar fasciectomy (in association with Dupuytren’s contracture). Anesthetic received (local, general, or regional) was then determined through a search of those respective CPT codes. The resulting records included demographic characteristics, insurance coverage, and patient county of residence. Counties of residence were then subcategorized based on population size (Rural: < two million, Micropolitan: > two – 3.9 million, Metropolitan: > four million). State-wide trends in anesthetic utilization for six common ambulatory hand procedures were then analyzed.

Study Population

Table 1 summarizes the CPT codes used in this study. Outpatient surgical procedures occurring between 2010 and 2019 were queried using the CPT codes 29848, 64721, 26055, 25000, 26116, and 26123. Likewise, outpatient anesthetic administration occurring between 2010 and 2019 was queried using the CPT codes 01810, 64450, 64415, 64416, 64417, 64418, 64420, 64421, 64999, and 20526. Procedures with no corresponding anesthetic code were assumed to employ a pure local anesthetic or WALANT, as this administration is not directly coded. To prevent record duplication, only the primary reported procedure was analyzed. A total of 340,117 procedures performed between 2010 and 2019 were included in the final analysis.

Table 1.

Ambulatory Hand Procedure and Associated Anesthetic CPT Codes

Procedure	CPT Code
ECTR	29848
Open CTR	64721
Trigger Finger Relese	26055
1st Compartment Release	25000
Mass Hand Excision	26116
Open Dupuytren's Partial Palmar Fasciectomy	26123
Regional Anesthetic	CPT Code
Injection, anesthetic agent; brachial plexus, single	64415
Injection, anesthetic agent; brachial plexus, continuous infusion by catheter (including catheter placement)	64416
Injection, anesthetic agent; axillary nerve	64417
Injection, anesthetic agent; suprascapular nerve	64418
Injection, anesthetic agent; intercostal nerve, single	64420
Injection, anesthetic agent; intercostal nerves, multiple, regional block	64421
Injection, anesthetic agent; carpal tunnel	20526
General Anesthetic	CPT Code
	01810
Local Anesthetic	CPT Code
Injection, anesthetic agent; peripheral nerve/ digital	64450
	No Code

Statistical Analysis

All statistical analyses were performed using STATA version 17.0. Count data were expressed as frequencies and percentages and Fisher Exact tests were utilized for comparisons. Mantel-Haenszel test was utilized to analyze the growth of respective anesthesia groups over the 10-year period (2010-2019). The Cochran-Armitage test for linear trend of proportions was used to compare the trends of anesthesia use in all three groups within the same period. All analyses were performed with an alpha level of 0.05, indicating statistical significance as less than 0.05.

Results

There were 340,117 procedures performed in the ambulatory outpatient surgical setting over a 10-year period (2010-2019). In terms of usage, 98.14% of these records met the criteria for LA application, while GA and RA only accounted for 0.41% and 1.45%, respectively. Over time, local anesthetic usage saw a slight average annual decline -0.12% during this study period (Figure 1). Conversely, the average annual growth rate of regional and general anesthetic usage saw an uptick in the same time frame [regional (0.09%), general (0.03%)]. Mantel-Haenszel test demonstrated that these individual growth rates for each form of anesthetic were insignificant. However, Cochran-Armitage test shows a significant difference in proportional growth when comparing all three anesthetics (p<0.001). A complete breakdown of anesthetic received for each procedure can be found below (Table 2).

Figure 1.

Trends in Anesthesia use Across Six Common Ambulatory Hand Procedures: 2010-2019.

Table 2.

Relative Anesthetic Utilization in Hand Procedures

	Local	General	Regional	Total
Endoscopic Carpal Tunnel Release	75,263	206	1,580	77,049
	97.68%	0.27%	2.05%	100%
Open Carpal Tunnel Release	138,074	688	2,260	141,022
	97.91%	0.49%	1.60%	100%
Trigger Finger Release	84,175	392	549	85,116
	98.89%	0.46%	0.65%	100%
1st Compartment Release	20,117	61	219	20,397
	98.63%	0.30%	1.07%	100%
Hand Mass Excision <1.5cm	4,642	11	20	4,673
	99.34%	0.24%	0.43%	100%
Open Dupuytren's Partial Fasciectomy Palmar	11,535	25	300	11,860
	97.26%	0.21%	2.53%	100%

Insurance designation was reported in 316,022 records, while only 268,062 noted county or state health regions of residence. Commercial/private insurance was found to be the most common payer regardless of anesthetic choice [local (62.39%), general (39.76%), and regional anesthetic (63.09%), p<0.001]. However, Medicaid payment source covered a larger proportion of procedures performed under general anesthetic (2.48%), in comparison to Medicare (0.37%), worker’s compensation (0.12%), or commercial/private insurance (0.20%, p<0.001) (Table 3). Local anesthetic was the most utilized anesthetic in every county and state health region [metropolitan (98.48%), micropolitan (97.22%), and rural (98.64%), p<0.001]. Micropolitan counties were notable for a higher percentage of regional anesthetic use compared to metropolitan and rural counties [metropolitan (1.10%), micropolitan (2.34%), and rural (1.05%), p<0.001] (Table 4).

Table 3.

Insurance Coverage for Anesthesia

	Local	General	Regional	Total
Medicare	99,539	371	1418	101,328
	98.23%	0.37%	1.40%	100%
Medicaid	8,327	215	124	8,666
	96.09%	2.48%	1.43%	100%
Workers’ Compensation	8,883	11	159	9,053
	98.12%	0.12%	1.76%	100%
Commercial	193,673	394	2,908	196,975
	98.32%	0.20%	1.48%	100%

Table 4.

Utilization of Anesthetic by State Population Grouping

	Local	General	Regional	Total
Metropolitan (> four million)	160,843	695	1790	163,328
	98.48%	0.43%	1.10%	100%
Micropolitan (two – 3.9 million)	97,029	446	2,331	99,806
	97.22%	0.45%	2.34%	100%
Rural (< two million)	75,934	242	807	4,928
	98.64%	0.31%	1.05%	100%

There were 333,795 records reporting age, which show that most procedures were performed in age groups between the ages of 50 and 69 across all forms of anesthesia. Patient's age at the time of procedure did not influence anesthesia choice. Finally, female patients were found to outnumber male patients in this study (214,990 versus 123,969, p<0.001).

Discussion

From 2010-2019, local anesthetic was far more often utilized in common ambulatory hand procedures. Although LA was the dominant anesthetic of choice for hand surgery in this cohort, all modalities were found to be growing/falling at insignificant rates. However, a significantly higher proportion of anesthesia utilization is trending towards general and regional modalities over time. We, therefore, reject our study hypothesis.

Foster and colleagues previously concluded that 80.5% of CTR procedures employed general or regional anesthesia between 2007-2011, while only 19.5% of procedures were performed using LA. However, LA usage was found to increase substantially from 2010-2011 by 4.7%.⁶ Similarly, Kamnerdnakta et al. concluded that approximately 80% of CTR, De Quervain release, and trigger finger release involved anesthesiologist-administered anesthesia services. The use of anesthesia services was found to decline by 3.9 % over their study period (2010-2015).⁷ These findings stand in contrast to our results, and we instead concur with previous survey studies which estimate that CTR performed with a local anesthetic is the most common practice.^3-5 Although a recovery trend back towards RA and GA use was found during our ten-year study period, LA (including WALANT) still dominated anesthetic utilization (>97% of all cases) year over year.

Our study also demonstrated a majority of commercial/private insurance reimbursement, which is consistent with the literature. Odom and colleagues previously identified a majority of private insurance reimbursement (54.7%), followed by Medicare (26.3%), worker’s compensation (10.5%), and Medicaid (8.5%).¹⁶ Our study also identified a similar pattern [commercial/ private (62.3%), Medicare (32.1%), worker’s compensation (2.9%), and Medicaid (2.7%)]. However, a higher proportion of Medicaid coverage for GA is notable in our study, as previous research has implicated LA as the least costly modality across the 6 procedures in this study.^6,17-24 Therefore, a small, albeit significantly higher proportion of low-income bracket patients are likely incurring more expensive procedures. Excessive use of anesthesia services has been previously demonstrated and may be attributable to our current fee-for-service system.⁷ However, further study is needed to ascertain the causation of this identified trend. Additionally, regional anesthetic use is disproportionally higher in Micropolitan counties (2.34%, p<0.001), though the reason for this remains unclear. Potential explanations include a higher volume of concomitant procedures, anxious patients, or poor patient pain tolerance.^13-14

As Texas is the 2nd most populous state representing a broad base of demographics, this study adds to previous literature providing clarity on preferred nationwide anesthesia methods in commonly performed ambulatory hand surgical procedures. However, as with any retrospective review of a healthcare database, our findings may be limited by documentation, coding, and data submission errors. As a state healthcare database intended for administrative use, detailed clinical information was not available. As a result, treatment outcomes, certain population demographics, or procedure indications were not obtainable in this study. In addition, this study did not examine treatment patterns by surgical specialty, fellowship training received, or board certification. It is unclear if these factors may have affected our data. Further work is also needed to address the proposed regional and socioeconomic disparities in care.