Clonidine Versus Ketamine to Prevent Tourniquet Pain During Intravenous Regional Anesthesia With Lidocaine:

Intravenous Regional Anesthesia: A Historical Overview and Clinical Review

Intravenous regional anesthesia (IVRA) is an established, safe and simple technique, being applicable for various surgeries on the upper and lower limbs. In 1908, IVRA was first described by the Berlin surgeon August Bier, hence the name "Bier's Block". Although his technique was effective, it was cumbersome and fell into disuse when neuroaxial and percutaneous plexus blockades gained widespread popularity in the early 20^th century. In the 1960s, it became widespread, when the New Zealand anesthesiologist Charles McKinnon Holmes praised its use by means of new available local anesthetics. Today, IVRA is still popular in many countries being used in the emergency room, for outpatients and for high-risk patients with contraindications for general anesthesia. IVRA offers a favorable risk-benefit ratio, cost-effectiveness, sufficient muscle relaxation and a fast on- and offset. New upcoming methods for monitoring, specialized personnel and improved emergency equipment made IVRA even safer. Moreover, IVRA may be applied to treat complex regional pain syndromes. Prilocaine and lidocaine are considered as first-choice local anesthetics for IVRA. Also, various adjuvant drugs have been tested to augment the effect of IVRA, and to reduce post-deflation tourniquet pain. Since major adverse events are rare in IVRA, it is regarded as a very safe technique. Nevertheless, systemic neuro- and cardiotoxic side effects may be linked to an uncontrolled systemic flush-in of local anesthetics and must be avoided. This review gives a historical overview of more than 100 years of experience with IVRA and provides a current view of IVRA with relevant key facts for the daily clinical routine.

The Addition of Sufentanil, Tramadol or Clonidine to Lignocaine for Intravenous Regional Anaesthesia

This study was designed to evaluate the effect of sufentanil, tramadol or clonidine added to lignocaine for intravenous regional anaesthesia. We investigated the onset and duration of sensory and motor block, the quality of the anaesthesia, intraoperative and postoperative haemodynamics, intraoperative and postoperative pain and sedation.

Sixty patients undergoing ambulatory hand surgery received intravenous regional anaesthesia using 35 ml of 0.5% lignocaine and either 5 ml saline (Group L, n=15); sufentanil 25 μg (Group LS, n=15); tramadol 100 mg (Group LT, n=15) or clonidine 1 μg.kg –1 (Group LC, n=15).

Before and after the tourniquet application, haemodynamic data, tourniquet pain, sedation scores and analgesic use were recorded. After tourniquet deflation, haemodynamic data, pain and sedation, time to first analgesic requirement and analgesic use were noted.

There were no differences among groups in intraoperative haemodynamic data, the time to recovery of sensory block, the onset and the recovery of motor block, sedation scores or postoperative pain. Compared to the other groups, in Group L the onset of sensory block was longer, the time to initial tourniquet pain was shorter and the intraoperative tourniquet pain scores and use of the opioid were higher (P<0.05). The quality of anaesthesia in Groups LS, LT and LC was better than in Group L (P<0.05).

In conclusion, the addition of sulfentanil, tramadol or clonidine to lignocaine shortened the onset of the sensory block, delayed the onset time of the tourniquet pain and reduced the intraoperative consumption of opioid, but did not affect postoperative pain.

Effects of Low Dose Ketamine on Tourniquet-induced Haemodynamic Responses during General Anaesthesia

This study investigated the effect of a pre-operative low dose of intravenous ketamine on tourniquet-induced haemodynamic changes. Ten minutes after induction of general anaesthesia, 0.1 mg/kg ketamine in 10 ml of saline (ketamine group, n = 14) or 10 ml of normal saline (control group, n = 14) were administered intravenously. Systolic and diastolic blood pressures, and heart rate relative to tourniquet inflation and deflation were recorded and compared within and between groups. Systolic and diastolic blood pressures in the control group significantly increased relative to baseline during the observation period following tourniquet inflation, but generally did not significantly increase in the ketamine group. The control group had a greater percentage of patients with a 30% rise in blood pressure at 60 min after tourniquet inflation compared with the ketamine group (28.6% vs 7.1%), but this was not statistically significant. We conclude that a pre-operative low dose (0.1 mg/kg) of intravenous ketamine can prevent a systemic arterial pressure increase for at least 60 min after tourniquet inflation under general anaesthesia.

The quaternary lidocaine derivative QX-314 produces long-lasting intravenous regional anesthesia in rats

Background

The lidocaine derivative, QX-314, produces long-lasting regional anesthesia in various animal models. We designed this study to examine whether QX-314 could produce long-lasting intravenous regional anesthesia (IVRA) in a rat model.

Methods

IVRA was performed on tail of rats. EC₅₀ (median effective concentration) of QX-314 in IVRA was determined by up-and-down method. IVRA on tail of rats was evaluated by tail-flick and tail-clamping tests. For comparison between QX-314 and lidocaine, 60 Sprague-Dawley rats were randomly divided into 6 groups (n = 10/group), respectively receiving 0.5 ml of 0.5% lidocaine, 0.25% QX-314, 0.5% QX-314, 1.0% QX-314, 2.0% QX-314 and normal saline. To explore the role of TRPV1 channel in IVRA of QX-314, 20 rats were randomly divided into 2 groups (n = 10/group), respectively receiving 0.5 ml of 1% QX-314 and 1% QX-314+75 µg/ml capsazepine. Toxicities of QX-314 on central nervous system and cardiac system were measured in rats according to Racine's convulsive scale and by electrocardiogram, respectively.

Results

QX-314 could produce long-lasting IVRA in a concentration-dependent manner. EC₅₀ of QX-314 in rat tail IVRA was 0.15±0.02%. At concentration of 0.5%, IVRA duration of QX-314 (2.5±0.7 hour) was significantly longer than that of 0.5% lidocaine (0.3±0.2 hour, P<0.001). TRPV1 channel antagonist (capsazepine) could significantly reduce the effect of QX-314. For evaluation of toxicities, QX-314 at doses of 5 or 10 mg/kg did not induce any serious complications. However, QX-314 at dose of 20 mg/kg (1% QX-314 0.5 ml for a rat weighing 250 g) induced death in 6/10 rats.

Conclusions

QX-314 could produce long-lasting IVRA in a concentration-dependent manner. This long-lasting IVRA was mediated by activation of TRPV1 channels. Evaluation of toxic complications of QX-314 confirmed that low but relevant doses of QX-314 did not result in any measurable toxicity.

Tourniquets in orthopedic surgery

Tourniquets are commonly used in limb surgeries, be it orthopedic or plastic surgeries. But the inflation pressures, the duration, and release guidelines are still not clear. According to a survey, majority of orthopedic surgeons inflate the tourniquet to fixed pressures for the upper and the lower limbs without considering the baseline blood pressure of the patient on whom the tourniquets are being applied. This review was designed to recall and review the safe use of tourniquets and the various techniques that can be employed to minimize the complications of tourniquet use. Google, science direct, and pubmed were searched for appropriate literature and relevant articles were identified.

Dexmedetomidine: clinical application as an adjunct for intravenous regional anesthesia

The selective α-2 adrenoceptor agonist, dexmedetomidine, has been shown to be a useful, safe adjunct in perioperative medicine. Intravenous regional anesthesia is one of the simplest forms of regional anesthesia and has a high degree of success. However, intravenous regional anesthesia is limited by the development of tourniquet pain and its inability to provide postoperative analgesia. To improve block quality, prolong postdeflation analgesia, and decrease tourniquet pain, various chemical additives have been combined with local anesthetics, although with limited success. The antinociceptive effects of α-2 adrenoceptor agonists have been shown in animals and in humans. However, less is known about the clinical effects of dexmedetomidine when coadministered with local anesthetics in patients undergoing intravenous regional anesthesia. This review examines what is currently known to improve our understanding of the properties and application of dexmedetomidine when used as an adjunct in intravenous regional anesthesia.

Clinical pain management peri-operative scenarios

This article reinforces the clinical points of emphasis that have been stressed throughout this issue in a case scenario format. Common situations dealt with by physicians are examined to highlight the underlying physiology of the specific complaints and treatment interventions. The goal of this article is to present an evidenced-based review of pain management interventions in a format that allows for reader incorporation.

Peri-operative pain management

Surgery is a circumstance in which we know that we will cause pain. Although most of our perioperative pain management interventions are symptomatic, several strategies can reduce and even prevent pain in the perioperative setting. Because the physiologic mechanisms of postoperative pain are understood, it is possible to interrupt these mechanisms before the patient actually becomes symptomatic. This article reviews the literature and presents these strategies with the hope of implementation of the readers.

Intravenous regional anesthesia administered by the operating plastic surgeon: is it safe and efficient? Experience of a medical center

BACKGROUND

Intravenous regional anesthesia (Bier's block) is an effective method of providing anesthesia for extremity surgery. This technique is most suitable for short-duration, less than 60-minute surgical procedures in distal extremities. Earlier studies recommended that intravenous regional anesthesia be performed by anesthesiologists who are familiar with the technique and fully trained to treat its complications. This study was conducted to demonstrate that intravenous regional anesthesia administered by the operating plastic surgeon is safe, efficient, and simple to perform.

METHODS

A 5-year retrospective chart review (January of 2000 to December of 2004) was undertaken. The study included patients who underwent surgical procedures and were administered intravenous regional anesthesia by the surgeon.

RESULTS

Four hundred forty-eight patients were included in the study, and 479 operations of 483 scheduled were completed under intravenous regional anesthesia performed by the operating surgeon. Intravenous regional anesthesia was efficient in 478 of 479 of the cases (99.8 percent). Tourniquet-related technical problems were noted in five of 483 cases (1 percent), resulting in cancellation of four operations, with no reported consequent anesthetic toxicity. Minor complications were reported in six of 479 of the cases (1.2. percent). No major complications occurred.

CONCLUSIONS

Despite earlier worries about the safety of intravenous regional anesthesia if not administered by anesthesiologists, the authors found that intravenous regional anesthesia represents a safe and efficient technique of anesthesia for extremity surgery when performed carefully and appropriately by the operating surgeon. The authors suggest that plastic surgeons familiarize themselves with this technique, which is simple to perform. This could probably result in lower overall costs and greater autonomy for the surgeon.

Clonidine--a potent analgesic adjuvant

PURPOSE OF REVIEW

The alpha(2)-adrenoceptor agonist clonidine is one of the most widely investigated substances in anaesthesia and pain therapy. Recently, numerous experimental and clinical studies have allowed a better understanding of its underlying mechanisms of action and interactions with other analgesic drugs.

RECENT FINDINGS

Several experimental studies have shown that clonidine may improve the analgesic effect of anti-inflammatory agents and also have significant peripheral antinociceptive effects. Volunteer and clinical studies have demonstrated analgesic effects of clonidine after systemic administration, whereas local administration of plain clonidine (e.g. intra-articular, intravenous regional) showed only limited clinical efficacy. The major clinical place of clonidine may thus be as an adjuvant to other analgesics, as shown in a number of studies in which clonidine has been investigated in combination with local anaesthetics, opioids and ketamine. An increasing number of studies have now investigated clonidine in paediatric patients and have demonstrated that the effects are generally similar to those in adults. Furthermore, it seems that in paediatric patients the side-effects of clonidine are predictable and of limited clinical importance.

SUMMARY

During the past decade clonidine has been investigated as an adjuvant for general and regional anaesthesia and in the postoperative period. There is no doubt that clonidine improves analgesia after systemic, spinal or peripheral opioids, and prolongs the analgesic action of most local anaesthetics. The side-effects of usual doses of clonidine are predictable. Given the clinical experience of an increasing number of hospitals, clonidine should no longer be considered an experimental drug, but a useful addendum to the pharmacological armamentarium.

[Is a blockade of the lateral cutaneous nerve of the thigh an alternative to the classical femoral nerve blockade for knee joint arthroscopy? A randomised controlled study]

BACKGROUND

Gaps in the distribution area of the lateral femoral cutaneous nerve (LFCN) are assumed to be the reason for pain caused by a thigh tourniquet when performing a femoral nerve (FN) block according to Winnie. The aim of the study was to evaluate if a direct single blockade of the LFCN in patients undergoing knee surgery resulted in a better tolerance to the tourniquet with equally good analgesic quality during surgery.

METHODS

A total of 40 patients undergoing knee arthroscopy received a proximal blockade of the sciatic nerve and randomly either an FN or an LFCN block. Practicability, onset time, quality of sensory and motor block, and clinical effectiveness during tourniquet and surgery were assessed.

RESULTS

Stimulation time was significantly longer in the LFCN than in the FN group. Quality of sensory and motor block was worse in the LFCN than the NF group. Of the LFCN patients 65% indicated troublesome paraesthesia or pain when a tourniquet was placed, compared to 35% of the FN patients. Of the LFCN patients 50% had pain during cutaneous incision, compared to none of the FN group. During the course of surgery, 70% of the LFCN patients needed supplemental systemic analgesia, but this was required by only 30% of the FN group.

CONCLUSION

An LFCN block is not a suitable alternative to an FN block for regional anaesthesia. For patients with contraindications for an FN block according to Winnie (e.g. vessel surgery in the groin) other more effective methods are available.

Role of Analgesic Adjuncts in Postoperative Pain Management

Postoperative pain remains a major problem. A multi-modal analgesic approach is recommended to optimize pain management and reduce opiate-related adverse effects. Several analgesic adjuncts have been investigated, and many have proved to have a useful analgesic effect. This article reviews the literature regarding use of analgesic adjuncts in the perioperative period.

0.5% Versus 1.0% 2-Chloroprocaine for Intravenous Regional Anesthesia: A Prospective, Randomized, Double-Blind Trial

In this randomized prospective double-blind study we tested the hypothesis that compared with 40 mL chloroprocaine 0.5%, 40 mL chloroprocaine 1% results in an earlier onset to analgesia duration and improves distal tourniquet tolerance in 150 patients undergoing forearm surgery under IV regional anesthesia using a double-cuff technique, switching from the proximal to the distal cuff was performed if pain scores increased above 4 of 10. Switching to the distal cuff resulted in pain scores below 4 in 69% of patients in the 0.5% group and in 88% of patients in the 1% group (P = 0.047). In addition, both groups differed in the sustained effect on distal tourniquet pain (P = 0.020). Time between injection and onset to analgesia duration was 13 +/- 1 min in the 0.5% group and 11 +/- 1 min in the 1% group (P = 0.0006). On release of the tourniquet, signs of systemic local anesthetic toxicity occurred in 6 patients of the 0.5% group and 28 of the 1% group (P < 0.0001). We conclude that chloroprocaine 1% resulted in an earlier onset of analgesia and improved distal tourniquet tolerance. However, these beneficial effects must be weighed against a fourfold increase in side effects.

IMPLICATIONS

Compared to a standard dose of 40 mL 0.5% chloroprocaine, 40 mL 1% chloroprocaine resulted in an earlier onset of analgesia duration and improved distal tourniquet tolerance during IV regional anesthesia. These beneficial effects must be weighed against a fourfold increase in signs of systemic local anesthetic toxicity.

Adding dexmedetomidine to lidocaine for intravenous regional anesthesia

Dexmedetomidine is approximately 8 times more selective toward the alpha-2-adrenoceptors than clonidine. It decreases anesthetic requirements by up to 90% and induces analgesia in patients. We designed this study to evaluate the effect of dexmedetomidine when added to lidocaine in IV regional anesthesia (IVRA). We investigated onset and duration of sensory and motor blocks, the quality of the anesthesia, intraoperative-postoperative hemodynamic variables, and intraoperative-postoperative pain and sedation. Thirty patients undergoing hand surgery were randomly assigned to 2 groups to receive IVRA. They received 40 mL of 0.5% lidocaine and either 1 mL of isotonic saline (group L, n = 15) or 0.5 microg/kg dexmedetomidine (group LD, n = 15). Sensory and motor block onset and recovery times and anesthesia quality were noted. Before and after the tourniquet application at 5, 10, 15, 20, and 40 min, hemodynamic variables, tourniquet pain and sedation, and analgesic use were recorded. After the tourniquet deflation, at 30 min, and 2, 4, 6, 12, and 24 h, hemodynamic variables, pain and sedation values, time to first analgesic requirement, analgesic use, and side effects were noted. Shortened sensory and motor block onset times, prolonged sensory and motor block recovery times, prolonged tolerance for the tourniquet, and improved quality of anesthesia were found in group LD. Visual analog scale scores were significantly less in group LD in the intraoperative period and 30 min, and 2, 4, and 6 h after tourniquet release. Intra-postoperative analgesic requirements were significantly less in group LD. Time to first analgesic requirements was significantly longer in group LD in the postoperative period. We conclude that the addition of 0.5 microg/kg dexmedetomidine to lidocaine for IVRA improves quality of anesthesia and perioperative analgesia without causing side effects.

IMPLICATIONS

This study was designed to evaluate the effect of dexmedetomidine when added to lidocaine for IV regional anesthesia. This is the first clinical study demonstrating that the addition of 0.5 microg/kg dexmedetomidine to lidocaine for IV regional anesthesia improves quality of anesthesia and intraoperative-postoperative analgesia without causing side effects.

Anaesthesia for procedures of the hand and elbow

The majority of upper extremity surgeries are performed on an ambulatory basis under intravenous regional anaesthesia or brachial plexus blockade. The former technique is easy to perform, has a rapid onset and a high success rate but provides limited post-operative analgesia. Brachial plexus blockade provides excellent intraoperative anaesthesia as well as post-operative analgesia, eliminates the need for post-operative opioids, resulting in a decrease in recovery time, shortened hospital stay, increased patient satisfaction and ultimately a decrease in perioperative costs when compared with general anaesthesia. This chapter reviews upper extremity surgical procedures performed below the shoulder, the anaesthetic options available, and techniques used to optimize post-operative pain control.