Safety and Efficacy of Forearm Tourniquet Compared to Upper Arm Tourniquet for Local Intravenous Regional Anesthesia in Hand Surgery: A Randomized Clinical Trial

Abstract

Background

Forearm tourniquets may offer decreased doses of anesthetic, shorter procedure times, and less pain compared to upper arm tourniquets. There is limited data comparing the clinical efficacy of forearm Bier blocks to conventional upper arm Bier blocks. The purpose of this study was to assess the effectiveness, complications, duration, cost, and patient satisfaction between forearm and upper arm Bier blocks during surgery.

Methods

Sixty-six carpal tunnel release, ganglion excision, or trigger finger procedures were performed. Patients were randomized to 3 groups: upper arm tourniquet for 25 minutes, forearm tourniquet for 25 minutes, or forearm tourniquet with immediate deflation following the procedure (<25 minutes). The efficacy of surgical anesthesia, tourniquet discomfort, and supplementary local anesthetic administration were recorded. Pain was assessed intraoperatively and postoperatively. Patient satisfaction was assessed on the first postoperative day.

Results

No difference was observed between groups with respect to pain, satisfaction, or administration of supplemental medication. The tourniquet time for the group with immediate deflation following procedure was shorter by an average of 9.3 minutes. Total hospital charges were 9.95% cheaper with immediate tourniquet deflation compared to procedures where the tourniquet remained inflated for at least 25 minutes.

Conclusion

The forearm Bier block is a safe, efficient, cost-effective technique for intravenous regional anesthesia during hand surgery, and tourniquet deflation immediately following the procedure (<25 minutes) does not increase incidence of complications. The forearm tourniquet reduces the dose of local anesthetic and therefore risk for systemic toxicity, with similar effectiveness as compared to the upper arm technique.

Level of Evidence: II

Introduction

Intravenous regional anesthesia (IVRA), otherwise known as a “Bier block”, is a well-known anesthetic technique introduced by Karl August Bier in 1908.¹ A Bier block involves exsanguination of an upper extremity and inflation of a tourniquet, followed by intravenous injection of anesthetic agent distal to the tourniquet. Traditionally, a dose of 50 mL of 0.5% lidocaine is infused intravenously.^2,3 Analgesia is achieved by direct diffusion of the anesthetic locally in the operative extremity with a tourniquet to block systemic circulation.

Local anesthetic systemic toxicity remains one of the most feared complications of Bier blocks. The risk of local anesthetic systemic toxicity includes seizures, cardiac arrhythmias⁴ or even rarely death.⁵ To minimize the risk of toxicity, by convention a double-cuff tourniquet has been used and remains inflated for a minimum of 30 minutes.^6-8 Prolonged tourniquet inflation time can also result in significant discomfort for the patient and extend surgical procedures that are otherwise shorter than 30 minutes. More recently, newer techniques of smaller-dose forearm Bier blocks have been introduced to minimize risks.⁹

The forearm tourniquet may offer advantages over the conventional upper arm tourniquet, including decreasing the risk of lidocaine toxicity by using a smaller dose of lidocaine (thereby enhancing the safety margin for the patient), decreasing the tourniquet time, shortening surgical procedures, and minimizing patient discomfort intraoperatively. Forearm Bier block has been described and demonstrated to be an effective method of anesthesia in literature with a success rate of 93-96%.^10-12 Although previous research has not demonstrated an increased complication rate with a shorter tourniquet duration,⁷ no clear guidelines exist as to a minimum “safe” tourniquet time for Bier blocks.

The purpose of this study was to assess the effectiveness, complications, duration, cost, and patient satisfaction between forearm and upper arm Bier block during hand surgery. To our knowledge, there is little prior data comparing the efficacy, costs, and complications of a low-dose forearm Bier block technique with a standardized, shorter tourniquet time to the conventional upper arm Bier block.

Methods

After obtaining institutional review board approval, we performed a randomized controlled study from adult patients undergoing hand surgical procedures at our institution. Patients over the age of 18 undergoing carpal tunnel release, ganglion excision, or trigger finger release were consented and enrolled in the study. Exclusion criteria included: patients with a contraindication to tourniquet use on the operative extremity (i.e. AV fistula), patients unable to cooperate with a visual analogue score, and patients with contraindications to Bier block (e.g. Raynaud’s phenomenon, homozygous sickle cell disease).

Patients were randomized to one of three study groups through computer-generated group randomization prior to the procedure (Table 1). All 3 study groups involved inflation of a pneumatic tourniquet inflated to 125 mmHg above systolic blood pressure, with a maximum of 300 mmHg. Group 1 used a double cuff tourniquet with only one cuff inflated at any given time, and groups 2 and 3 used a single cuff tourniquet. Patients assigned to group 1 had the cuff placed proximal to the elbow joint, with a minimum inflation time of 25 minutes. Patients randomized to group 2 had the cuff placed distal to the elbow joint, with a minimum inflation time of 25 minutes. Patients randomized to group 3 had the cuff placed distal to the elbow joint, with immediate deflation following completion of the procedure regardless of tourniquet time. The protocol for the upper arm technique (group 1) was intravenous injection of 50 mL of 0.5% lidocaine, and for the lower arm technique (groups 2 and 3) 25 mL 0.5% lidocaine was injected. For all groups, patients were premedicated with up to 2 mg of midazolam and 50 mcg of fentanyl.

Table 1.

Study Design Characteristics

Study Group	Cuff Placement	Lidocaine Dose	Inflation Time
Group 1	Upper arm	50 mL (0.5%)	25 minutes
Group 2	Forearm	25 mL (0.5%)	25 minutes
Group 3	Forearm	25 mL (0.5%)	Immediate deflation

All patients premedicated with 2 mg of midazolam and 50 mg of fentanyl

During the procedure, the anesthesia provider monitored and recorded any adverse events including abnormalities in the EKG, systolic blood pressure fluctuations, symptoms of local anesthetic toxicity including tinnitus, perioral tingling, visual disturbances, and dizziness. Tourniquet inflation time, total procedure time, and any need for supplementary local anesthetic or anxiolytic were recorded, as well as verified through review of the electronic medical record. Patients also reported an intraoperative pain score using the visual analogue scale (VAS) score from 0 to 10; 0 representing no pain and 10 for the worst pain. Postoperatively, patients were monitored for adverse events in the post-anesthesia care unit (PACU), and another VAS score was reported 30 minutes after the conclusion of the procedure. On the first postoperative day, patients were administered the Iowa Satisfaction with Anesthesia Scale (ISAS) via phone survey. The ISAS is comprised of 11 questions, and it has been shown to be a reliable and valid primary study end point in multicenter clinical trials (Table 2).¹³ Each question is given an individual score ranging from -3 to +3, and the cumulative question scores are averaged to determine a final composite score. A final score of +3 represents the most satisfied a patient can be with their anesthesia experience, while a final score of -3 represents the least satisfied a patient can be with their anesthesia experience. Total hospital charges associated with each procedure were obtained from the billing department and were subcategorized into anesthesia charges, charges for operating room services, drug charges, and charges associated with the use of the recovery room.

Table 2.

The Iowa Satisfaction with Anesthesia Scale (Dexter, et al.)

Statements	Response choices
I threw up or felt like throwing up	-3 = Disagree very much
I would want to have the same anesthetic again	-2 = Disagree moderately
I itched
	-1 = Disagree slightly
I felt relaxed
I felt pain	1 = Agree slightly
I felt safe
I was too cold or hot	2 = Agree moderately
I was satisfied with my anesthetic care
	3 = Agree very much
I felt pain during surgery
I felt good
I hurt

The Iowa Satisfaction with Anesthesia Scale is copyrighted, franklin Dexter and the University of Iowa Research Foundation. Permission to use the questionnaire may be obtained at https://www.franklindexter.net.

The 11 statements that make up the Iowa Satisfaction with Anesthesia Scale alternate between “negative” and “positive” statements. Responses to statements are given an individual score ranging from -3 to +3, the scores for the “negative” statements are multiplied by -1, and the cumulative scores are averaged to determine a final composite score. A final score of +3 represents the most satisfied a patient can be with their anesthesia experience, while a final score of -3 represents the least satisfied a patient can be with their anesthesia experience.¹³

A statistical power analysis was performed for sample size estimation to determine the number needed to detect a significant statistical difference between groups. Because of the paucity of studies that compare complications of Bier block techniques, the power analysis was performed based on data from a similarly-designed study by Chaio et al. comparing the use of a forearm versus arm upper arm tourniquet.¹⁴ In that study, for an effect size of greater than 30% on pain ratings per group (alpha = 0.05, power = 0.90), 54 patients were required. Using the same sampling ratio, the projected sample size needed for this study was a minimum of 20 patients per group. We analyzed the total hospital charges associated with each encounter as well as each of the subcategories individually using a Student’s t-test. Group analysis was by parametric analysis for continuous variables and chi-squared test for categorical variables. P-values less than 0.05 were considered significant.

Results

A total of 66 procedures were included in the study (Table 3). Fifty-five patients were enrolled in the study, and 11 of these patients had bilateral procedures performed on separate dates. There were seven patients who declined to be included in the study, with no apparent trends in age or gender. Surgeries in each group were similar and included 63 carpal tunnel releases (95.5%), 2 ganglion excisions (3.0%), and 1 trigger finger release (1.5%). There were no intraoperative or postoperative complications in any group. Intraoperative (p=0.518) and postoperative (p=0.926) VAS pain scores were similar between all groups. There were no significant differences between groups in patient satisfaction measured on the first postoperative day using the ISAS (p=0.556) (Figure 1). The average tourniquet time for group 3 was 16.2 minutes (standard deviation 3.4 mins), shorter by an average of 9.3 minutes (p<0.001) (Figure 2). The use of supplementary analgesic and anxiolytic interventions was recorded, and there were no differences in the frequency or amount of supplemental medication between groups. Total hospital charges were 9.95% less for group 3 compared to groups 1 and 2.

Table 3.

Study Group Characteristics

	Group 1	Group 2	Group 3
Participants	21	23	22
Average Age (SD)	53.7 (15.4)	50.3 (14.3)	53.6 (11.4)
Intra-op VAS (SD)	1.60 (2.50)	1.10 (2.57)	1.23 (2.16)
Post-op VAS (SD)	0.55 (1.23)	0.83 (2.14)	0.35 (1.57)
Tourniquet Time (SD)	26.2 (2.41)	24.9 (2.59)	16.2 (3.38)
Complications	0	0	0
Additional Local	9.5%	13.0%	18.2%
Additional Benzo/ Opioid	23.8%	34.8%	18.2%

Figure 1.

There was no significant difference between groups in terms of patient satisfaction measured on the first postoperative day using the ISAS (p=0.556). All 3 groups were satisfied overall with their anesthesia experience.

Figure 2.

Immediate deflation of the tourniquet at the conclusion of the procedure let to a significant decrease in tourniquet time (9.3 minutes) for group 3.

Discussion

The purpose of this study was to compare the overall efficacy and safety of the upper arm and forearm Bier block in hand surgery, as well as assess cost savings using the forearm technique. Our data indicates that compared with traditional methods, a forearm Bier block technique with immediate tourniquet deflation following conclusion of the procedure is a safe, efficient, and cost-effective strategy to provide intravenous regional anesthesia during hand surgery. There was no statistical difference between groups in terms of complications, pain scores, patient satisfaction, or additional medication given during the procedure. We were able to demonstrate that the safety and efficacy of the forearm technique with immediate tourniquet deflation following the procedure is comparable to the upper arm technique and, additionally, led to a decrease in total hospital charges by 9.95% at our institution secondary to a shorter amount of time spent in the operating room and decreased medication costs.

Our results compare favorably with previous studies assessing the safety of forearm tourniquet placement for local intravenous anesthesia in hand surgery. Since its original description in 1978 by Rousso, it has been noted that the major advantage of using a forearm tourniquet is the potential to use a lower dose of local anesthetic to achieve satisfactory anesthesia.^9-12,15,16 Hesitation for implementing the forearm tourniquet has occurred due to the theoretical risk of leakage of local anesthetic through interosseous vessels in the forearm.¹⁷ However, no study has demonstrated that the forearm tourniquet produces an increased risk of venous or arterial leaks.^4,7,11,18 Specifically, Coleman et al. provided a quantitative comparison of leakage under the tourniquet in forearm versus upper arm IV regional anesthesia and found no difference between the two techniques.¹⁸

In one of the first studies to evaluate the anesthetic dose required for adequate pain control, Plourde et al. showed that 1.5 mg/kg of 0.5% lidocaine solution is sufficient to produce satisfactory analgesia.¹¹ The standardized anesthetic dose (25 mL of 0.5% lidocaine) used for the forearm technique in our patient population was based on the retrospective review of 105 patients conducted by Arslanian et al. that was published in 2014. The study demonstrated that using 25 mL of 0.5% lidocaine with a forearm tourniquet and an average tourniquet time of 10.1 minutes resulted in no complications and adequate intraoperative analgesia.⁷

We sought to compare the overall effectiveness of the forearm technique compared with the upper arm technique in terms of pain scores during and immediately following the procedure, as well as patient satisfaction with their anesthesia experience. To date, there have been 3 randomized controlled trails investigating the analgesic efficacy of the upper arm tourniquet in IVRA compared to the forearm tourniquet.^14,19,20 These studies span a variety of distal upper extremity procedures performed on a total of 129 patients, and their results were analyzed in a 2018 systematic review and meta-analysis performed by Dekoninck et al. The authors’ concluded that IVRA using a forearm tourniquet technique is as efficient as using an upper arm tourniquet. In addition, the authors noted that use of a forearm Bier block comes with the advantages of a lower need for sedation due to less tourniquet pain, faster onset of sensory block, better tourniquet tolerance, and a drier surgical field.²¹

This study demonstrates that there is no statistical difference in intraoperative or postoperative pain using a forearm Bier block versus an upper arm Bier block, which agrees with the previous studies mentioned previously. Additionally, there was also no difference in patient satisfaction measured using the ISAS (Figure 1). Although scores trended toward increased satisfaction with forearm tourniquet placement, this difference was not statistically significant. The 3 groups included in this study had final scores ranging from 2.13 to 2.30, indicating that all groups were very satisfied overall with their experience.

Our average tourniquet time for study group 3 was 16.2 minutes, shorter than the average for groups 1 and 2 by 9.3 minutes (Figure 2). This reduction in time demonstrates that procedures amenable to Bier Block anesthesia are typically quicker than the conventional 25-30 minutes of tourniquet time, and that the ability to deflate the tourniquet at the end of the procedure decreases the amount of operating room time and increases efficiency. At our institution, the mean of the total hospital charges for study group 3 was reduced by 9.95% compared to study groups 1 and 2 (10.4% reduction compared to study group 1, and 8.5% reduction comparted to study group 2) by immediately releasing the tourniquet following the completion of the procedure (p<0.001). This cost reduction is a direct result of spending a shorter amount of time in the operating room as well as decreased medication costs. Considering the regularity at which these types of procedures are performed¹⁹ any potential cost-saving measure merits further investigation.

Limitations to this study include the fact that the majority of the surgeries included in this study were performed by a single surgeon, and all surgeries were performed at a single institution. The vast majority of procedures performed in this study were carpal tunnel releases, a relatively short procedure with a focal area requiring anesthesia. We cannot conclude from our study that the forearm Bier block method would be as efficacious with a more invasive procedure. Furthermore, although guidelines were provided regarding amount and specific sedative medications to utilize, different anesthesia providers had different styles and approaches to analgesia, leading to some subtle variability in the supplemental sedatives administered to supplement the Bier block.

Conclusion

This study demonstrates that the use of a forearm Bier block is a safe and efficient method of analgesia for intravenous regional anesthesia during hand surgery. While there is no clear benefit in terms of post-operative pain scores or patient satisfaction, the forearm Bier block with tourniquet deflation at the end of the procedure provides several other advantages including a reduction in required operating room time and associated decrease in hospital charges.