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A bier block implementation protocol.

There is a demand for emergency procedures for extremity injuries that minimize time and expense, while still adequately providing treatment. One of these procedures is the Bier block. The advantages of the Bier block lie in the lack of sedating anesthesia, enabling a patient to be quickly treated and discharged with minimal allocation of resources, rather than that required for procedural sedation and certainly general anesthesia. Procedural sedation in the emergency department setting for most protocols requires 2 physicians and at least one nurse. This large provider requirement has the practical effect of almost shutting down one side of a busy emergency department. Completion of the presedation packet can take as long as 15 minutes before any part of patient care is even initiated. The recovery phase from procedural sedation can require an otherwise available bed for as long as an hour, thus presenting a risk of resource shortage for incoming serious emergencies. Lastly, in deployed environments, there is a need to use anesthetic methods that do not incapacitate a Soldier, and do not divert the attention of another Soldier-provider from the care of other patients for solely monitoring sedated patients.

CURRENT INDICATIONS

According to Roberts and Hedges, (1) the Bier block is indicated for procedures including reduction of fractures and dislocations, repair of major lacerations, removal of foreign bodies, debridement of burns, and drainage of infection. Other factors in the decision to use a Bier block are the desire for a bloodless operating field as well as avoiding possible adverse effects of axillary blocks. Furthermore, the Bier block has the advantage of not requiring respiratory monitoring as does procedural sedation. The patient need not be NPO (nothing by mouth) for a Bier block, but, if possible, the procedure should be delayed if the patient has recently eaten a large meal.

CONTRAINDICATIONS

Contraindications include allergy to the anesthetic, uncontrolled hypertension, a preexisting ischemic limb from a crush injury, or disease states such as homozygous sickle cell disease, Reynaud's disease, or Buerger's disease. In addition, the Bier block should not be used in procedures which require monitoring of pulses in the distal extremity, such as a supracondylar fracture reduction. A pneumatic tourniquet is a required equipment item that must be used to administer a Bier block. The block is used for procedures lasting between 30 and 90 minutes in duration. The block can be used in both upper and lower extremity blocks, with modification as discussed further, although Wheeless recommends the Bier block only for the upper extremity. (2) Morbid obesity is also a relative contraindication, since it is difficult to apply effective tamponade pressure to the obese arm with the tourniquet to prevent systemic lidocaine toxicity.

SAFETY OF BIER BLOCKS

The question of safety is relevant in the case of the Bier block, especially with regard to use of the pneumatic pressure tourniquet, and the use of high dose lidocaine (1.5 mg/kg to 3 mg/kg). Several studies have been conducted to assess safety, the larger of which are listed below. There have been no reported cases of mortality resulting from the Bier block procedure. (3)

Whistler Health Care Center (2005-2006, Mohr (4)): a retrospective study involving 1,804 patients who received Bier block anesthesia for wrist, hand, and forearm injuries. Twelve of the patients received bilateral Bier blocks. There was no significant mortality or morbidity, although there were 9 cases of adverse events (0.5%). These included one medication error (0.06%) and 3 cases of improper cuff inflation (0.17%), resulting in tinnitus and dizziness from partial lidocaine entry into the circulation. These conditions resolved after a 30-minute monitoring period. There were 5 cases of inadequate analgesia. The procedure was successfully completed in all cases, as confirmed by c-arm imaging.

Royal United Hospital/Bristol Medical School (2008-2010, Jakeman et al (3)): another retrospective study of 416 patients receiving Bier blocks. There were 39 complications noted in this study. The complications included transient hypotension, vasovagal episodes, and transient mild bradycardia. No medical intervention was required for any of the episodes. There was no case of significant morbidity or mortality.

Emergency Department Treatment of Childern's Extremity Fractures: Blasier and White (5) detail a 1996 study of 470 children who underwent fracture reduction using the Bier block method from 1989 through 1994. All but 12 patients were successfully reduced. Nine of the 12 required surgical fixation in the operating room. In the other 3 cases, IV access could not be obtained for the Bier block. Two patients complained of significant tourniquet pain. One had a transient metallic taste in his mouth. One patient complained of transient facial tingling without any changes in electrocardiogram readings. There were no cases of hypotension, tachycardia, seizures, or arrhythmia. There were no cases of decreased extremity sensation or neurological function.

EFFECTIVENESS

Handoll et al (6) compared anesthesia techniques and found 5 trials which provided evidence that, when compared with hematoma block, intravenous regional anesthesia provided better analgesia during fracture manipulation and enabled better and easier reduction of the fracture, with additional findings of reduced risk of later redislocation or need for re-reduction. In contrast, hematoma blocks can be performed more easily and quickly, and are less resource intensive.

BIER BLOCK PROTOCOL

The following are 8 steps to simplify Bier block administration:

1. Initiate painless sedation protocol.

2. Obtain IV access.

3. Elevate or apply Eschmarch bandage to the affected extremity.

4. Tourniquet is applied.

5. Lidocaine is injected.

6. Attempt the procedure.

7. Inspect for signs/symptoms of lidocaine toxicity.

8. Deflate the tourniquet.

Details of Each Step in the Bier Block Protocol

1. Initiate painless sedation protocol 45 to 18 minutes before the procedure (T-45 to T-18 minutes).

Roberts and Hedges (1) recommend consideration of premedication with midazolam, diazepam, or fentanyl, but not necessary on a routine basis. Resusitation equipment and anticonvulsant drugs should be readily available. Ensure that suction is available. Consider delay if the patient has just eaten a large meal. The following is an effective prevascular access method for presedation:

(a) T-45 minutes--First apply EMLA[R] cream or LMX4[R] cream about 45 minutes prior at IV sites if time allows. Place the patient on the cardiac monitor.

(b) T-18 minutes--Give intranasal fentanyl at 2 //g/kg and intranasal Versed[R] at 0.2 mg/kg.

2. Obtain IV access (T-15 minutes).

The first IV line is place in the noninjured forearm for administration of sedation and fluids. In the injured limb, a butterfly needle is placed in a dorsal vein in the hand, distal to the fracture site.

3. Exsanguinate the extremity (T-14 to T-10 minutes).

This is done either by elevation of the extremity for 4 minutes or use of an Eschmark bandage. Use elevation only in the case of extremity infections. Elevation for 4 minutes can easily be done by using finger traps.

4. Deploy the tourniquet (T-6 minutes).

Prior to performing the Bier block, be sure that the tourniquet is working properly. If the tourniquet malfunctions and deflates during the case, the patient may have a seizure due to lidocaine toxicity. The tourniquet must specifically be a double pneumatic tourniquet to prevent failure and deliver the exact amount of pressure needed. This is because the lidocaine maximum dosage (3 mg/kg) used in a Bier block is twice the cardiac dose of lidocaine (1.5 mg/ kg). Pressure is 100 mm Hg above the systolic BP in the arm in adults, 150 mm Hg above systolic BP in the legs in adults and 50 mm Hg above systolic BP in children. (7) Marcaine[R] or any similar long acting anesthetic should never be used, since the medication will still be active when the tourniquet is deflated at the end of the case (causing a seizure). Contraindications include excessive obesity (ie, a large fatty arm), causing excessive tissue damage from necessarily increased tourniquet pressures. For moderately obese patients, the double tourniquet may not provide adequate tamponade pressure to prevent leakage of the lidocaine into the systemic circulation. In this case, if it is determined to continue the Bier block procedure, it may be necessary to use a wide single tourniquet to apply the necessary tamponade force to the obese extremity.

5. Lidocaine administration (T-5 minutes).

Dose using the "mini-Bier block dose," 1.5 mg/kg of a 0.5% solution. For a 70 kg male, this is 105 mg, or 22 mL. The maximum "full dose Bier block" is 3 mg/kg. (8) Start with the mini-Bier block dose. If more anesthetic is needed in 10 minutes, continue to the full dose Bier block.

6. Attempt procedure (T-zero).

There will reliably be between 35 to 45 minutes of anesthesia, before the lidocaine is eventually bound to the tissues. After 20 to 30 minutes, the patient will likely begin to experience pain from the tourniquet. To treat tourniquet pain, first inflate the distal cuff and then slowly deflate the proximal cuff. The distal cuff is therefore now inflated over anesthetized tissue. The inflation must be done in the correct sequence to avoid systemic introduction of lidocaine.

7. Inspect for signs of lidocaine toxicity.

The first sign of lidocaine toxicity is perioral tingling and tinnitus. The patient may also complain of a metallic taste sensation. The patient must be on a cardiac monitor. Look for increasing PR interval and QRS lengthening.

At 5 [micro]g/mL, EKG findings of cardiac toxicity begin.

At 10 [micro]g/mL, seizures begin to occur.

At 30 [micro]g/mL, cardiovascular depression begins to manifest.

If these things happen, give IV fluids to treat hypotension. Use push-dose epinephrine to maintain blood pressure with the following method:

Take 1 mL of 1:10,000 cardiac Epi (100 [micro]g/mL concentration).

Add 9 mL to make 1:100,000 Epi (10 [micro]g/mL concentration).

Give 0.5 mL (range of 0.5 mL to 2 mL) every 2 to 5 minutes. This is about the same as an epinephrine drip at 1 to 10 [micro]g/min.

Obtain TPN for lipid rescue. * First give an initial intravenous bolus of 20% lipid emulsion (approximately 1.5 ml/kg of lean body mass), followed immediately by a continuous infusion (approximately 0.25 to 0.5 ml/kg/min) for roughly 10 minutes following recovery of vital signs. Repeat the bolus as needed every 5 minutes for cardiac instability. (10)

8. Deflate the tourniquet.

The tourniquet cannot be deflated until at least 25 minutes have transpired since inflation. For additional safety, a 30 minute minimum time to deflation will be used for the protocol. It must then be deflated in a cyclic manner. Deflate over 5 seconds, and then reinflate for 1 to 2 minutes. Repeat this process 3 to 4 times. (7)

Watch the patient for 30 minutes, monitoring for lidocaine toxicity. Peak plasma lidocaine concentrations occur 2 to 4 minutes after cuff deflation, and are minimized by using the cyclic deflation technique. Cardiac toxicity with EKG abnormalities to lidocaine occur between 5 [micro]g/mL and 10 [micro]g/mL plasma concentration. The maximum lidocaine plasma concentration from a Bier block after a properly cycled tourniquet release is 2 [micro]g/mL to 4 [micro]g/mL plasma concentration. Some patients will sense a temporary ringing in their ears, perioral tingling, or a metallic taste. Other reactions include dizziness, headache, and blurred vision. All of these reactions are temporary, occur in about 3% of cases, and no treatment is required. More serious complications include transient seizures, bradycardia, and hypotension which are treated as appropriate. These are most commonly caused by large lidocaine boluses resulting from a tourniquet mistake or failure. There are no reports of deaths from these complications.

Send the patient home with pain control. The tourniquet area will be sore for 1 to 2 days. Although no lingering effects are expected, Roberts and Hedges (1) recommend that the patient not drive for 6 to 8 hours after the procedure.

SAFETY MEASURES INCLUDED IN THE PROTOCOL

* Only use double pneumatic tourniquets. An acquisition process should be implemented detailing the specifications required, so that the various models of tourniquets can be compared objectively.

* There should be a Bier block tool box. Inside will be lipid rescue, diazepam, push-dose epinephrine, and sodium bicarbonate. It should also contain a laminated instruction guide and the brief evaluation forms for research documentation and tracking.

* The tourniquets will only be deflated after 30 minutes, and then at cyclic deflation. The tourniquets will not be inflated for longer than 90 minutes.

* The toxic dose of IV lidocaine (3 mg/kg) should not be exceeded.

FUTURE RESEARCH QUESTIONS TO BE ADDRESSED BY THE PROTOCOL

* Do Bier blocks provide an enhanced means of antibiotic delivery to contaminated/infected wounds?

* Bier blocks have been used for complex regional pain syndrome in some locations. There is little data on the effectiveness. Is this a possible application?

* There is little study into the effectiveness of sodium bicarbonate pretreatment before cuff release. Is this a plausible option for minimizing adverse effects?

* Toradol has been used as an anesthetic enhancement. Is this effective adjunct?

* One of the issues of previous studies was the lack of long term follow-up for patients. This is important in determining the ultimate effectiveness of the procedure. An established method of contacting the patients should be established.

* An emergency department cost accounting method should be identified. This will help in the determination of cost effectiveness as the protocol is implemented.

REFERENCES

(1.) Roberts JR, Hedges JR. Robert and Hedges Clinical Procedures in Emergency Medicine. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2009:535-539.

(2.) Wheeless CR III, ed-in-chief; Nunley JA II, Urba niak JR, managing eds. Wheeless' Textbook of Orthopaedics [internet]. Duke University Department of Orthopaedic Surgery. Available at: http://www. wheelessonline.com/. Accessed February 11, 2014.

(3.) Jakeman N, Kaye P, Hayward J, Watson DP, Turner S. Is lidocaine Bier's block safe?. Emerg Med J. 2013;30(3):214-217.

(4.) Mohr B. Safety and effectiveness of intravenous regional anesthesia (Bier block) for outpatient management of forearm trauma. Can J Emerg Med. 2006;8(4):247-250.

(5.) Blasier RD, White R. Intravenous regional anesthesia for the management of children's extremity fractures in the emergency department. Pediatr Emerg Care. 1996;12(6):404-406.

(6.) Handoll HH, Madhok R, Dodds C. Anesthesia for Treating Distal Radial Fracture in Adults (Review). Hoboken, NJ: John Wiley & Sons; 2009. Available at: http://www.thecochranelibrary.com/userfiles/ ccoch/file/CD003320.pdf. Accessed February 11, 2014.

(7.) Crystal CS, McArthur TJ, Harrison B. Anesthetic and procedural sedation techniques for wound management. Emerg Med Clin North Am. 2007;25(1):41-71.

(8.) Mattu A, Chanmugan AS, Swandron SP, Tibbles CD, Woolridge DP, eds. Avoiding Common Errors in the Emergency Department. Philadelphia, PA: Lipincott Williams & Wilkins; 2010:561.

(9.) Weinberg GL, VadeBoncouer T, Ramaraju GA, Garcia-Amaro MF, Cwik MJ. Pretreatment or resuscitation with a lipid infusion shifts the doseresponse to bupivacaine-induced asystole in rats. Anesthesiology. 1998;88(4):1071-1075.

(10.) Weinberg G. Lipid emulsion infusion: resuscitation for local anesthetic and other drug overdose. Anesthesiology. 2012;117(1):180-187.

CPT Stewart A. Stancil, MC, USA

CPT Stancil is an Emergency Medicine Resident at the Darnall Army Medical Center, Fort Hood Texas.

* Use of TPN was identified by Weinberg, who noted in 1998 that animals were resistant to bupivacaine toxicity when they were cotreated with TPN (9) Since then, TPN has become an accepted treatment modality for lidocaine overdose. It has also been proven effective for overdoses of beta blockers, bupropion, lamotrigine, calcium channel blockers, and tricyclic antidepressants. (10)
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Title Annotation:procedures for intravenous regional anesthesia
Author:Stancil, Stewart A.
Publication:U.S. Army Medical Department Journal
Geographic Code:1USA
Date:Apr 1, 2014
Words:2584
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