Venous pressures during simulated Bier's block

Tourniquet Deflation Prior to 20 Minutes in Upper Extremity Intravenous Regional Anesthesia

BACKGROUND

Bier blocks, or intravenous regional anesthesia (IVRA), are a method of anesthesia for upper extremity surgeries. This study reports our experience with tourniquet deflation prior to 20 minutes with upper extremity IVRA.

METHODS

This study was designed as a retrospective cohort analysis. Records, including intraoperative and immediate postoperative anesthesia notes, of 430 patients who underwent IVRA with an upper extremity Bier block and a corresponding tourniquet time of less than 20 minutes were reviewed. Patient demographics, procedure(s) performed, American Society of Anesthesiologists scores, volume of lidocaine used in Bier block, tourniquet time, and any complications were recorded.

RESULTS

This cohort consisted of 127 males and 303 females. The 3 most common procedures performed were carpal tunnel release (315), trigger finger release (47), and excision of masses (34). The average tourniquet time for this cohort was 16 minutes (range, 9-19 minutes), and the average volume of lidocaine (0.5% plain) injected was 44 mL (range, 30-70 mL). A tourniquet time of 17 minutes or less was observed in 339 patients, and 170 patients had tourniquet times of 15 minutes or less. Five complications were recorded: intraoperative vomiting, mild postoperative nausea/vomiting, severe postoperative nausea and vomiting, and transient postoperative hypotension that responded to a fluid bolus.

CONCLUSIONS

No major complications were observed in our cohort of upper extremity IVRA and tourniquet times of less than 20 minutes. Several variables play a role in the safety of upper extremity IVRA.

Simple Arm Tourniquet as an Adjunct to Double-Cuff Tourniquet in Intravenous Regional Anesthesia

BACKGROUND

Intravenous Regional Anesthesia (IVRA) is a well-known technique for producing analgesia during surgical procedures in the extremities. However, the rapid onset of pain following the deflation of a double-cuff tourniquet during IVRA is a serious disadvantage, leading patient suffering.

OBJECTIVES

The aim of this study was to evaluate the clinical effectiveness of a pneumatic arm tourniquet applied 2 cm above the double-cuff tourniquet in controlling the pain that occurs after its deflation.

PATIENTS AND METHODS

Twenty patients undergoing outpatient hand surgery were operated on under IVRA, using 40 - 50 mL of a solution containing 3 mg/kg of lignocaine. A simple pneumatic tourniquet was applied proximal to the double-cuff tourniquet, 3 min before its deflation, while the procedure was being conducted. The severity of pain on the basis of the Numerical Rating Scale (NRS) was assessed throughout the operation, and continued until an hour after the double-cuff tourniquet was removed.

RESULTS

The mean operation time after the deflation of the double-cuff tourniquet was 20.12 ± 6.1 minutes. Moreover, the mean NRS for the post-deflation time was insignificant (NRS = 2), and only one patient during first 20 minutes received opioids.

CONCLUSIONS

This study showed that a pneumatic arm tourniquet as an adjunct to IVRA provides acceptable analgesia following the deflation of the double- cuff tourniquet for relieving surgical pain.

Bier block exsanguination: a volumetric comparison and venous pressure study

OBJECTIVES

Intravenous regional anesthesia (IVRA) is a useful ED anesthetic technique. However, venous pressure elevation during injection can cause anesthetic leakage and toxicity. This is minimized by preinjection limb exsanguination. Although standard, Esmarch exsanguination is intolerable with limb trauma. Thus, the authors' objective was to study alternative methods.

METHODS

Volunteers had upper limb exsanguination performed by Esmarch bandage, arm elevation/arterial compression (AE/AC), and a pneumatic vinyl splint. Resultant volume changes, measured by volume displacement, were normalized, and expressed as percent decreases from baseline. Volume changes of all three methods were compared. The physiologic effectiveness of the AE/AC method was tested by measuring IV pressures during simulated IVRA. Attainment of maximum venous pressure (MVP) indicated leakage under the tourniquet.

RESULTS

All methods reduced limb volume compared with baseline (p < 0.05). No difference occurred between AE/AC and vinyl splint exsanguination (p > 0.99), but neither method was as effective as Esmarch (p < 0.05). Gender differences were noted in absolute volumes exsanguinated, but there was no difference in percent exsanguination. The AE/AC method was the simplest procedure to perform. Peak IV pressure during simulated IVRA after AE/AC was 85 mm Hg (males), and 199 mm Hg (females) (p < 0.05). The MVP was not reached.

CONCLUSIONS

While Esmarch was the most effective exsanguinating method, the two alternatives provided significant and equivalent decreases in limb volume. The AE/AC technique was physiologically effective in preventing attainment of MVP. Further studies are indicated to determine the clinical effectiveness of this technique in providing anesthesia for patients with limb trauma.

Intravenous regional analgesia with prilocaine for foot surgery. The effect of slow injections and high tourniquet inflation pressures

Intravenous regional analgesia for foot surgery with an ankle tourniquet was used for 48 cases. Prilocaine 0.5% 3 mg/kg body weight was injected either quickly over about 2 minutes or slowly over about 5 minutes. The tourniquet was inflated either to occlusion pressure plus 100 mmHg or to occlusion pressure plus 200 mmHg. Plasma prilocaine levels were measured while the tourniquet remained inflated and after release of the tourniquet. All four techniques resulted in a low incidence and magnitude of prilocaine leak and low prilocaine plasma levels after tourniquet release. The data suggest that slow injection with the high tourniquet inflation pressure is better, although the differences in leakage with an intact tourniquet were not statistically significant. Excellent analgesia was achieved in over 90% of patients and there were no complete failures. No dangerously high prilocaine plasma levels were produced and no serious side effects observed.

Intravenous regional anaesthesia (Bier block): review of 20 years' experience

Our experience with intravenous regional anaesthesia (IVRA) in 1,906 patients over a period of 20 years has confirmed that this technique is safe and effective. IVRA may be used to provide anaesthesia for surgery involving both the upper and lower extremities. The need for supplemental medication is ordinarily minimal, so the technique is particularly suitable for short procedures in an ambulatory surgery centre. Yet, prolonged surgery may be performed using a "continuous technique." Although various local anaesthetic agents may be used to induce IVRA no drug has been demonstrated to be superior to lidocaine. The major cause of failure of the technique or serious adverse effects is technical error. A specific protocol for avoiding technical error is presented. Significantly, over a period of 20 years, there has not been any mortality or major morbidity. The incidence of adverse reactions was 1.6 per cent and consisted of minor events such as transient dizziness, tinnitus or mild bradycardia.

Intravenous regional anaesthesia of the arm. Effect of the technique of exsanguination on the quality of anaesthesia and prilocaine plasma concentrations

The effects of different techniques of exsanguination of the upper arm during intravenous regional anaesthesia on prilocaine plasma concentrations, quality of anaesthesia, toxic symptoms after deflation of the tourniquet and injection pressure of the anaesthetic were studied in 10 healthy male volunteers. The nondominant arm was exsanguinated using either Esmarch's bandage or elevation of the arm for 2 minutes plus arterial occlusion by compression of the brachial artery. The injection pressure after the prilocaine dose (3 mg/kg) was significantly higher in the elevation group (maximally 98 mmHg). There were no statistically significant differences in the onset of, or recovery from, anaesthesia between the groups. Various mild toxic symptoms were experienced in the central nervous system after deflation of the tourniquet. However, there was no correlation between the two techniques and the degree of severity of the toxic symptoms. The highest single venous plasma concentration (total) of prilocaine was 2.3 micrograms/ml measured from the contralateral cubital vein (elevation group, 2 minutes). The differences in prilocaine concentrations between the groups were not statistically significant.

Intravenous regional analgesia with a forearm tourniquet

Lidocaine 0.5 per cent in a dose of 2 mg X kg-1 was used for intravenous regional analgesia with the tourniquet cuff placed over the forearm. The level of tourniquet cuff pressure employed was the arterial "occlusion pressure" plus 50 mmHg. In 48 normotensive patients successful analgesia was achieved; in seven hypertensive patients, four were pain-free, but the other three required more lidocaine to achieve adequate analgesia. No toxic symptoms and signs were observed. Measurement of serum lidocaine concentrations in 12 patients confirmed the safety of the technique, although small leakage of lidocaine past the inflated forearm tourniquet was detected in some patients.

Intravenous regional anaesthesia for foot surgery

Intravenous regional anaesthesia, confined to the distal lower limb and using bupivacaine 0.25%, was studied in 12 patients undergoing orthopaedic procedures to the feet. The technique was well accepted by both surgeons and patients and was free from serious toxicity. Bupivacaine was demonstrated in the systemic venous circulation in every case prior to surgery, whilst the tourniquet remained deflated. The plasma bupivacaine levels were less than that associated with toxicity, except in one case exhibiting signs of minor toxicity (bupivacaine plasma level 1.99 micrograms/ml-1). Reasons for the leak in spite of a well-conducted technique are discussed.