Intravenous Regional Anesthesia Using a Forearm Tourniquet: A Safe and Effective Technique for Outpatient Hand Procedures

Abstract

Background: Bier block provides anesthesia of an entire extremity distal to the tourniquet without necessitating direct injection at the surgical site. This avoids obscuring anatomy with local anesthetic and anesthetizes a wide area, allowing for multiple procedures and incisions. We hypothesize that a low-volume Bier block with forearm tourniquet, rather than a traditional brachial tourniquet, is a safe, well-tolerated, and effective anesthesia technique. Methods: All cases in which adult patients underwent hand procedures using Bier block anesthesia by a single surgeon over a 4-year period were reviewed. Data collected included patient demographics, procedure(s) performed, complications, tourniquet time and settings, procedure and in-room time, and supplemental medications administered. Results: In all, 319 patients were included, 103 from a university hospital and 216 from an ambulatory surgery center. The most commonly performed procedures were carpal tunnel release (205 cases) and trigger digit release (83 cases). Most patients received a 125-mg dose of lidocaine for the Bier block; many also received additional sedatives. Twenty-three patients received no additional medications. No patients required conversion to general anesthesia. One complication (0.3%) occurred, with paresthesias and tinnitus that resolved without intervention. The average tourniquet time was 24 minutes (SD = 4.3 minutes). Patients were discharged at a median of 49 minutes postoperatively, and 9.1% of patients received supplemental analgesics prior to discharge. Conclusions: Regional anesthesia achieved with a forearm tourniquet and intravenous local anesthetic provides adequate pain control, permits timely discharge home, and has a low complication rate. It should be considered for use in outpatient hand procedures.

Introduction

Anesthetic selection for outpatient hand procedures has been an evolving field. Some upper extremity procedures historically performed under general anesthesia can now be performed under local or regional anesthetic instead. The Bier block, first described in 1908 by Dr August Bier, is a regional anesthetic technique that involves intravenous (IV) injection of local anesthetic after inflation of a tourniquet on the operative extremity proximal to the injection site. This is less commonly used than extravascular injections with or without the use of IV sedation for outpatient hand surgery,¹ but a Bier block has several advantages over local infiltration of anesthetic. A wider region is anesthetized, allowing easy extension of surgical incisions. It covers the entire forearm distal to the tourniquet, permitting multiple procedures with one anesthetic injection, as is not uncommon in hand surgery. The visualization of the surgical site is markedly better without edema from local anesthetic infiltration, with preserved tissue planes and more easily identified anatomic structures. This is a notable advantage in teaching settings, as both the learner and the supervising physician can better see the surgical field. There is no motor blockade associated with the Bier block, allowing active motion during surgery. With rapid onset and quick recovery, it is a predictable, effective anesthetic technique.

Historically, the Bier block was performed using a double-cuff tourniquet on the upper arm, injecting 40 to 50 mL (200-250 mg) of 0.5% lidocaine.² Critics of the technique cite the potential for leakage of the anesthetic, particularly when a forearm tourniquet is used given the presence of the relatively incompressible interosseous vessels. While rare, systemic toxicity can cause lightheadedness, tinnitus, bradycardia, or more serious complications such as seizures, cardiac arrest, and death.³ As such, the evolution of the technique has centered on administration of lower anesthetic volumes and controlled release of the tourniquet, with hopes of limiting the systemic release of the drug. The use of a forearm tourniquet permits a reduction in the volume of local anesthetic required to achieve an adequate anesthesia when compared with a brachial tourniquet, allowing deflation of the cuff in a shorter time.^4,5 Because less muscle and tissue are made ischemic, less pain is experienced with a forearm tourniquet compared with an upper arm tourniquet, allowing better patient comfort and a longer tolerance time.^6,7

Few reports of an antebrachial tourniquet have been released, and these have been relatively limited, often with small sample sizes and with strict exclusion criteria.^4,5,8-10 Moreover, no reports have compared the use of this technique in the hospital setting with an ambulatory surgery center (ASC). The goal of this article is to investigate the safety and efficacy of a Bier block using a forearm tourniquet for outpatient hand surgery. Secondary outcomes include surgical duration, tourniquet times, postanesthesia care unit (PACU) times, and the use of supplemental anesthetic and analgesic in the perioperative and postoperative periods.

Materials and Methods

The study was performed under the auspices of the institutional review board. Billing and scheduling data were reviewed over a 4-year period, from January 1, 2014, to December 31, 2017, to identify all patients who underwent outpatient hand procedures with the use of a Bier block as primary anesthetic. Patients were excluded if they were under 18 years of age, pregnant, prisoners, or had a history of cognitive impairment. Data were collected from both a university hospital (UNIV) center via electronic chart review and by a paper and electronic review of charts from an ASC. All procedures were performed by the same hand fellowship–trained attending surgeon, most commonly with the assistance of an orthopedics or plastic surgery resident. Data collected included patient demographics, preoperative use of narcotic pain medications, type of procedure(s) performed, presence of complications after tourniquet deflation related to local anesthetic toxicity, tourniquet time and settings, procedure duration, total operative in-room time, and doses of supplemental anesthetic medications administered both intraoperatively and postoperatively.

Procedural Details

An IV is placed into the patient’s dorsal hand in the preoperative holding area if possible; otherwise, it is placed by the anesthesia team after entering the operative suite. A second IV is also placed in the nonoperative hand or arm for fluid and medication administration. Standard monitoring systems are utilized. A well-padded tourniquet is applied to the forearm, just distal to the elbow flexion crease. The arm is exsanguinated with an Esmarch bandage, with the IV still in place in the dorsal hand, and the tourniquet cuff is inflated. The inflation pressure is set to be a minimum of 100 mm Hg above the patient’s systolic blood pressure (typically 250-275 mm Hg). It is critical to set the tourniquet pressure sufficiently above systolic pressure—if the patient’s blood pressure exceeds that of the tourniquet, it is not possible to deflate the tourniquet and re-exsanguinate during the procedure.

After confirmation of a functional tourniquet (absence of radial and ulnar pulses, pallor of the hand), 20 to 25 mL (100-125 mg) of 0.5% lidocaine is injected through the previously placed IV. During injection, the IV site is observed to be sure the catheter does not displace during exsanguination. No local infiltration should be seen, and the patient’s veins should be seen to insufflate with fluid. The IV catheter is removed, and manual pressure is applied to the IV site with a sterile prep solution–saturated gauze while prepping the extremity. The surgical procedure is then performed. Patients are administered supplemental sedation and analgesia per patient request to achieve a desired level of sedation. Specific medication selection is at the discretion of the anesthesiologist. At the conclusion of the case, 0.5% bupivacaine is infiltrated for prolonged postoperative pain control. In most cases, the timing of the surgery permits deflation of the tourniquet at or just beyond 20 minutes of tourniquet time. In several select cases, the tourniquet is deflated prior to 20 minutes. Upon deflation of the tourniquet at the completion of the case, the patient is instructed to alert the surgical and anesthesia team if they experience ringing in their ears, lightheadedness, perioral numbness, a metallic taste in their mouth, or other abnormal sensations. At the conclusion of the procedure, patients are transported to the PACU and discharged when ready.

Results

Patient Demographics

In all, 319 patients were identified for inclusion in this series: 103 from the UNIV and 216 patients from the ASC. The average age was 56 years (min = 19, max = 92, SD = 15). In total, 88 men and 231 women were included in the study. The average body mass index was 31.7 (min = 17.7, max = 62.7, SD = 7.3) and 51% of patients were obese. The most common comorbidities were hypertension (44%), gastroesophageal reflux disease (38%), depression or anxiety (32%), and hyperlipidemia (26%). Table 1 describes the comorbidities of the groups in detail. Eleven percent of the patients were taking narcotic pain medications at the time of surgery.

Table 1.

Patient Demographics.

	UNIV	ASC	Total
Age, y	59.2 (14.5)	54.4 (14.4)	56.0 (14.6)
BMI	34.5 (8.4)	30.4 (6.4)	31.7 (7.3)
ASA Score	2.4 (0.6)	2.0 (0.5)	2.1 (0.6)
Hypertension	67%	33%	44%
Gastroesophageal reflux disease	57%	29%	38%
Depression, anxiety, or bipolar disorder	34%	31%	32%
Hyperlipidemia	44%	17%	26%
Diabetes	32%	13%	19%
Thyroid disease	20%	15%	17%
Obstructive sleep apnea	22%	9.3%	13%
Cancer	14%	9.3%	11%
Current narcotic use	20%	6.0%	11%
Current smoker	13%	8.8%	10%
Coronary artery disease and/or congestive heart failure	21%	2.8%	8.8%
Autoimmune disorders	5.8%	3.7%	4.4%
Venous thromboembolism	8.7%	1.4%	3.8%
Chronic obstructive pulmonary disease	6.8%	1.9%	3.4%
Stroke or transient ischemic attack	5.8%	1.9%	3.1%
Chronic kidney disease	7.8%	0.9%	3.1%
Fibromyalgia	3.9%	1.9%	2.5%
Atrial fibrillation	43.9%	2.3%	2.8%

Note. UNIV = university hospital; ASC = ambulatory surgery center; BMI = body mass index; ASA = American Society of Anesthesiologists.

Surgical Characteristics

Eighty-two percent of patients had a single procedure performed at the time of their surgery, while 18% had multiple procedures performed (eg, concurrent carpal tunnel and trigger digit releases; Table 2). The most common procedure by far was carpal tunnel release (205 performed). The average time in the operating room was 39 minutes (min = 27, max = 70, SD = 7.6; Figure 1). This was significantly higher in UNIV patients when compared with ASC patients (UNIV = 45 minutes [SD = 6.8], ASC = 36 minutes [SD = 6.4], P < .05 in 2-tailed Student t test). The average procedural time was 18 minutes (min = 10, max = 48, SD = 5.6). There were no significant differences in procedural times between the ASC (18 minutes, SD = 5.9) and the UNIV (19 minutes, SD = 5.0) patients, with a P value of .43. There was, however, a significant difference in the relative amount of procedural time compared with the total room time when comparing the ASC (42% of total room time) and the UNIV (50% of total room time) procedures (P < .05). Ninety-seven percent of patients received additional local anesthetic at the completion of the procedure, with an average of 7.8 mL of 0.5% bupivacaine administered (min = 3, max = 14, SD = 2.0). The average tourniquet time was 24 minutes (min = 12, max = 43, SD = 4.3) and was similar though slightly higher in the UNIV patients compared with the ASC patients (25.1 minutes vs 23.6 minutes, P < .05). The average cuff pressure was 263 mm Hg (min = 250, max = 300, SD = 12).

Table 2.

Procedure Summary.

Procedure	Count	% of total
Carpal tunnel release	205	56.2
Trigger digit release (single digit)	62	17.0
First extensor compartment release	36	9.9
Trigger digit release (multiple digits)	21	5.8
Injection (trigger digit or joint)	10	2.7
Cyst excision (ganglion, retinacular, or mucus)	7	1.9
Sixth extensor compartment release	4	1.1
Second extensor compartment release	4	1.1
Other (eg, excision of foreign body, second extensor compartment tenolyses, neuroma excision and burial, closed reduction and pinning of metacarpal base and shaft fracture, and excision of carpal boss)	16	4.4
Total	365

Figure 1.

Time spent in the room and the time to perform the procedure. While the procedure times were the same regardless of operative setting, the percentage of the in-room time spent operating was significantly higher in the ambulatory surgery center.

Note. ASC = ambulatory surgery center; UNIV = university hospital.

Intraoperative Medication Administration

An average of 127 mg of 0.5% lidocaine was administered for the Bier block, most commonly as 125 mg (25 mL) doses. Many patients received a small dose of midazolam or fentanyl prior to the procedure. Other intraoperative analgesics included 2% lidocaine, propofol, Tylenol, Toradol, and ketamine (Table 3). Twenty-three patients received no additional medications beyond the Bier block, and 69 patients (22%) received supplemental fentanyl or midazolam after the incision had been made.

Table 3.

Perioperative Medications.

	Count (No. of patients)	Average dose	SD	Minimum	Maximum
Preoperative medications used for analgesia and sedation
Midazolam	260	1.9 mg	0.6 mg	0.25 mg	4 mg
Fentanyl	248	65 µg	32 mcg	13 µg	200 µg
Propofol	70	140 mg	116 mg	11 mg	681 mg
Toradol	27	29 mg	4.0 mg	15 mg	30 mg
Lidocaine	13	42 mg	40 mg	1 mg	166 mg
Ketamine	4	33 mg	12 mg	25 mg	50 mg
Tylenol	2	825 mg	247 mg	650 mg	1000 mg
Perioperative medications used for supplemental analgesia after incision
Fentanyl	67	46 µg	23 µg	25 µg	50 µg
Midazolam	10	1 mg	0.4 mg	0.5 mg	1 mg
	Count (No. of patients)	%
Postoperative medications used for supplemental analgesia in the PACU
Any medication (UNIV)	17	17
Any medication (ASC)	12	5.6

Note. PACU = postanesthesia care unit; UNIV = university hospital; ASC = ambulatory surgery center.

Complications

There was one patient who noted adverse effects as a result of the Bier block, for an overall complication rate of 0.3%. This occurred in a 57-year-old woman undergoing a first extensor compartment release at the ASC. The procedure time was 21 minutes, and the tourniquet time was 22 minutes. Upon deflation of the tourniquet, she experienced “paresthesias and ringing in [her] ears, but no arrhythmias.” These symptoms resolved prior to her discharge without need for any additional intervention. She was given 2 mg midazolam and 50 µg fentanyl preoperatively at the discretion of the anesthesia team. She received 5 mL of subcutaneous 0.5% bupivacaine upon completion of the case. She was discharged from the PACU after 45 minutes of monitoring.

Otherwise, no block-related complications were noted. No patient required conversion to general anesthesia.

Postoperative Course

Patients spent an average of 57 minutes (median of 49 minutes) in the PACU before discharge (min = 20, max = 313, SD = 31). The time in PACU was significantly lower at the ASC, with an average of 45 minutes (SD = 16) compared with 83 minutes (SD = 39) for UNIV patients (P < .05). Only 11% of patients remained in the PACU longer than 90 minutes before discharge. It was uncommon for patients to receive supplemental pain medication in the PACU; only 29 patients required additional medication (17 UNIV patients and 12 ASC patients; Table 3). This included 15 patients who received 5 mg of Norco, Percocet, or oxycodone; 10 patients who received 10 mg of Norco, Percocet, or oxycodone; 1 patient who received 30 mg of Toradol; and 1 patient who received 100 µg of fentanyl. Five of those patients were taking narcotics preoperatively.

Discussion

This series describes over 300 patients who successfully underwent surgery with a low-dose, forearm tourniquet, Bier block, with an overall complication rate related to the Bier block of 0.3%. A forearm tourniquet for IV regional anesthesia can be used safely for a variety of outpatient hand procedures in both a UNIV and an ASC setting. This technique provides excellent anesthesia with unaltered visualization of anatomic planes and tissues while avoiding general anesthesia.

While the Bier block does require the tourniquet to be inflated for a longer period of time, this is well tolerated by the patient and can be done in a way as to avoid operative delays. By performing the Bier block prior to prepping and draping, the anesthetic has time to take effect while the limb is prepared and the surgical field readied. Should the procedure conclude prior to what is felt by the surgeon and anesthesiologist to be a “safe” period of tourniquet inflation, dressings can be applied while the tourniquet is still inflated, again minimizing delays.

The technique holds significant advantages over direct infiltration of local anesthetic, especially in a teaching setting, as the pertinent surgical anatomy is not distorted by fluid and tissue edema. This allows for improved supervision of surgical learners and easier identification of anatomic variants, such as aberrant motor branches during carpal tunnel surgeries. In addition, by anesthetizing the entire distal forearm, multiple procedures in separate areas can be performed under one anesthetic. Because the Bier block anesthetizes the entire limb distal to the tourniquet through a “field effect” rather than by individually anesthetizing each nerve, there is uniform anesthesia achieved, without patchy areas of “missed” nerves as can occur with other regional anesthetic techniques.

While regional anesthetics have greatly improved with ultrasound guidance and increased expertise within the anesthesia field, the Bier block is an optimal choice for hand procedures. Performed in the operating room, it has rapid onset, and anesthesia is achieved within a few minutes of lidocaine injection. Unlike brachial plexus blocks or other more proximal regional anesthetic techniques, there is no motor blockade. Bier block allows patients to dynamically participate in the surgery (eg, confirm a trigger digit has been successfully released); the tourniquet is usually not inflated long enough for patients to develop tourniquet-induced paralysis. In addition, the Bier block is short-lived; patients can rapidly return to full function following tourniquet deflation, allowing for efficient postprocedure discharge.

Several other reports have discussed the use of a Bier block for regional anesthetic of the forearm. Arslanian et al described a series of 121 procedures in 105 patients in which a forearm Bier block was used.⁸ Twenty-five milliliters of 0.5% lidocaine was injected for the block, and patients were interviewed by telephone 24 hours postoperatively. There were no complications reported and all patients stated that they had adequate anesthesia during the procedure. Given the study design, however, it was inherently subject to recall bias. The average tourniquet time was 10 minutes, ranging from 5 to 48 minutes, and the total operative time was less than 30 minutes in all cases. The authors noted that “most patients also received supplemental medication of varying doses such as sedation. However, none of our patients were converted to general anesthesia because of insufficient analgesia.” Our current study addresses this concept in more detail, with actual records of what additional medications were provided to each patient and whether any unplanned/“rescue” medications were used after the start of the procedure.

Aydogan reviewed 120 patients in whom 13 different hand procedures were performed under forearm Bier block.⁹ Unlike in our series, they restricted their patient population to American Society of Anesthesiologists (ASA) I and II. The providers did not use any other supplemental analgesics during the procedures; the medication was restricted to 10 mL of 1.5 mg/kg prilocaine. They reported that the average onset of a sensory block occurred at 4.5 minutes (range = 3.5-7 minutes) and that the average tourniquet time in their patients was 17.6 minutes (range = 7-27.5 minutes). This highlights the difference between the total tourniquet time and the procedure time; the Bier block can be administered prior to sterile prep of the arm to “use up” a portion of the recommended tourniquet time. One patient requested removal of their tourniquet at 5 minutes. There were no complications from the Bier blocks.

Chiao et al compared the use of a forearm tourniquet with an upper arm tourniquet.⁴ In this small randomized controlled study (28 patients in each study arm), 2% lidocaine and ketorolac were used in a Bier block and patient pain and surgical times were compared. If the patient reported pain over 4/10, additional supplemental fentanyl was provided; if the patient reported over 6/10 pain, deep sedation was administered. There were no significant differences in tourniquet times or tourniquet pressures. More patients reported pain scores >4 in the upper arm group (n = 27) compared with the forearm group (n = 10), and more patients required deep sedation with propofol in the upper arm group (n = 28) compared with the forearm group (n = 1). As a result, 19 of the 28 patients could go straight to phase 2 PACU in the forearm group, while none of the upper arm group could bypass phase I. This is reflected in our results as well; patients rarely required supplemental analgesia after incision, and the vast majority patients were discharged from the hospital or surgery within 90 minutes.

Singh et al also reported the use of a forearm tourniquet versus an upper arm tourniquet; lidocaine and ketorolac were used in a prospective randomized study of 40 patients.⁵ Pain was recorded at 5-minute intervals intraoperatively, and if a pain score of >30 was reported, diclofenac was administered. The authors noted a similar time of onset of anesthesia, but a longer tourniquet tolerance time in the forearm group (27 minutes vs 30 minutes). There were similar Visual Analog Scale scores at 30 and 60 minutes and no significant differences in the forearm versus the upper arm groups in the success of intraoperative pain control. One patient in each group “failed” and required conversion to general anesthesia. One patient in the upper arm group reported symptoms of lidocaine toxicity (tinnitus and drowsiness); no adverse effects were noted in the forearm tourniquet group. This series, though small, further solidifies the concept that a forearm tourniquet is a safe alternative to upper arm tourniquet.

Gurich released a retrospective cohort analysis in 2017 in which for 79 procedures upper arm tourniquets were used and for 351 procedures forearm tourniquets were used.¹⁰ The lidocaine had been dosed to fall below 3 mg/kg in each patient. Supplemental medications were also administered “at the discretion of the anesthesia team” and included propofol, fentanyl, and Versed. The tourniquet was deflated at an average of 16 minutes (range = 9-19 minutes), once the surgical dressing had been applied. The average dosing of lidocaine was higher than in our series—220 mg (44 mL of 0.5% plain; range = 30-70 mL). They reported 5 complications, including intraoperative vomiting, postoperative nausea and vomiting, and transient postoperative hypotension that responded to a fluid bolus. In the decision to deflate the tourniquet prior to 20 minutes, one must balance the risks of this type of complication with the benefit of a slightly shorter time in the operating room. One must also consider that the overall time that patients remain in the hospital is increased by these complications. In our series, 8 patients had tourniquet times less than 20 minutes, with a minimum of 12 minutes. It is unclear from this retrospective review why the tourniquet was deflated prior to 20 minutes; however, per the surgeon’s recollection, it was typically done in error by the circulating nurse. None of these patients experienced adverse events in relation to the Bier block.

There are several limitations to this study. As a retrospective review, this series is somewhat limited by the data available in the medical record and the possible human error related to data collection and processing. Different anesthesia providers had different styles and approaches to analgesia, leading to variability in the supplemental sedatives administered to supplement the Bier block. This series examines the practices of a single surgeon and might be different if multiple providers were included.

In conclusion, a Bier block with a forearm tourniquet can be used with or without supplemental sedation or analgesia, per patient preference. Local anatomy is preserved, improving patient safety and surgeon identification of aberrant structures. Multiple procedures can be performed at distinct locations with one anesthetic. Patients can be discharged safely in a timely manner from the hospital or surgery center. Although its use is no longer widespread, we feel it is a safe, effective, and valuable anesthetic option for outpatient hand surgery.