Bier's block; 100 years old and still going strong!

Analgesic Techniques for Managing Orthopedic Injuries: A Review for the Emergency Clinician

BACKGROUND

Orthopedic injuries are commonly managed in the emergency department (ED) setting. Fractures and dislocations may require reduction for proper management. There are a variety of analgesic and sedative strategies to provide patient comfort during reduction.

OBJECTIVE

This narrative review evaluates hematoma block, intra-articular injection, intravenous regional analgesia (IVRA) (also known as the Bier block), and periosteal block for orthopedic analgesia in the ED setting.

DISCUSSION

Analgesia is an essential component of management of orthopedic injuries, particularly when reduction is necessary. Options in the ED setting include hematoma blocks, intra-articular injections, IVRA, and periosteal blocks, which provide adequate analgesia without procedural sedation or opioid administration. When used in isolation, these analgesic techniques decrease complications from sedation and the need for other medications, such as opioids, while decreasing ED length of stay. Emergency clinicians can also use these techniques as analgesic adjuncts. However, training in these techniques is recommended prior to routine use, particularly with IVRA.

CONCLUSIONS

Knowledge of analgesic techniques for orthopedic procedures can assist clinicians in optimizing patient care.

Manipulation of distal radius fractures: a comparison of Bier's block vs haematoma block

INTRODUCTION

Displaced distal radius fractures often require manipulation under anaesthesia. Many anaesthetic techniques are described, with the two most commonly used being Bier's block (BB) and haematoma block (HB). Despite national guidance preferring a BB, an HB is often performed instead. This study aims to compare the analgesic properties of a BB with those of an HB when manipulating distal radius fractures.

METHODS

This is an observational cohort study comparing the management of displaced distal radius fractures requiring reduction across two National Health Service trusts. Patients aged over 18 with isolated, displaced distal radius fractures were recruited. Patient demographics, AO fracture classification and grade of clinician performing the procedure were recorded. A numeric rating scale (NRS) pain score was obtained for each patient after manipulation. The quality of reduction was judged against standardised anatomical parameters.

RESULTS

Some 200 patients were recruited (100 HB, 100 BB). There were no differences in age (BB: median 66.5 years, interquartile range [IQR] 55-74; HB: median 67 years, IQR 55-74; p = 0.79) or fracture characteristics (p = 0.29) between cohorts. Patients undergoing BB had significantly lower pain scores with a lower IQR than those undergoing HB (p < 0.005). Patients undergoing BB manipulation were more likely to have the fracture reduced and normal anatomy restored (p < 0.005). BBs were performed mainly by Foundation Year 2 junior doctors, whereas HB manipulations were performed by a range of clinicians from emergency nurse practitioners to consultants.

CONCLUSIONS

BB provides better analgesia than an HB. This can be performed successfully and reliably by Senior House Officer-level junior doctors.

Prevalência de variações anatômicas encontradas em pacientes com síndrome do túnel do carpo submetidos a liberação cirúrgica por via aberta clássica

Objective  To evaluate the prevalence of anatomical variations encountered in patients with carpal tunnel syndrome who underwent carpal tunnel classical open release.

Methods  A total of 115 patients with a high probability of clinical diagnosis for carpal tunnel syndrome and indication for surgical treatment were included. These patients underwent electroneuromyography and ultrasound for diagnostic confirmation. They underwent surgical treatment by carpal tunnel classical open release, in which a complete inventory of the surgical wound was performed in the search and visualization of anatomical variations intra- and extra-carpal tunnel.

Results  The total prevalence of anatomical variations intra- and extra-carpal tunnel found in this study was 63.5% (95% confidence interval [CI]: 54.5–72.4). The prevalence of the carpal transverse muscle was 57.4% (95% CI: 47.8–66.6%), of the bifid median nerve associated with the persistent median artery was 1.7% (95% CI: 0.0–4.2%), and the median bifid nerve associated with the persistent median artery and the transverse carpal muscle was 1.7% (95% CI: 0.0–4.2%).

Conclusion  The most prevalent extra-carpal tunnel anatomical variation was carpal transverse muscle. The most prevalent intra-carpal tunnel anatomical variation was median bifid nerve associated with the persistent median artery. The surgical finding of an extra-carpal tunnel anatomical variation, such as the transverse carpal muscle, may indicate the presence of other associated carpal intra tunnel anatomical variations, such as the bifid median nerve, persistent median artery, and anatomical variations of the recurrent median nerve branch.

The analgesic efficacy of forearm versus upper arm intravenous regional anesthesia (Bier's block): A randomized controlled non-inferiority trial

STUDY OBJECTIVE

This study aimed to assess if a forearm (FA) intravenous regional anesthesia (IVRA) with a lower, less toxic, local anesthetic dosage is non-inferior to an upper arm (UA) IVRA in providing a surgical block in patients undergoing hand and wrist surgery.

DESIGN

Observer-blinded, randomized non-inferiority study.

SETTING

Operating room.

PATIENTS

280 patients undergoing hand surgery were randomly assigned to UA IVRA (n = 140) or FA IVRA (n = 140).

INTERVENTIONS

Forearm IVRA or upper arm IVRA in patients undergoing hand and wrist surgery.

MEASUREMENTS

The primary outcome was block success rate of both techniques. Block success was defined as no need of additional analgesics. A second, alternative non-inferiority outcome was defined as no need of conversion to general anesthesia. A difference in success rate of <5% was considered non-inferior. Secondary endpoints were tourniquet pain measured with a Numerical Rating Scale (0-10), satisfaction of patients and surgeons, onset time, surgical time and total OR time.

MAIN RESULTS

Non-inferiority of block success rate, defined as no need of additional analgesics or conversion to general anesthesia was inconclusive (5.24%, 95% CI:-4.34%,+14.82%). Non-inferiority of no need of conversion to general anesthesia was confirmed (+0.73%, 95% CI:-0.69%,+2.15%). No differences were observed in onset time (FA: 5 (5, 8) vs UA: 6 (5, 7) min, p = 0.74), surgical time (FA: 8 (5, 12) vs UA: 7 (5, 11) min, p = 0.71), nor total OR stay time (FA: 34 (27, 41) vs UA: 35 (32, 39) min, p = 0.09). Tourniquet pain after 10 min was significantly lower after FA IVRA compared to UA IVRA (FA: 2.00 (0.00, 4.00) vs UA: 3.00 (1.00,5.00) min, p = 0.003).

CONCLUSION

We failed to demonstrate non-inferiority of forearm IVRA with a lower dosage of LA in providing a surgical block without rescue opioids and LA. Non-inferiority of no need of conversion to general anesthesia was confirmed.

Efficacy of ultrasound-guided forearm nerve block versus forearm intravenous regional anaesthesia in patients undergoing carpal tunnel release: A randomized controlled trial

Background and objectives

Distal upper extremity surgery is commonly performed under regional anaesthesia, including intravenous regional anaesthesia (IVRA) and ultrasound-guided forearm nerve block. This study aimed to investigate if ultrasound-guided forearm nerve block is superior to forearm IVRA in producing a surgical block in patients undergoing carpal tunnel release.

Methods

In this observer-blinded, randomized controlled superiority trial, 100 patients undergoing carpal tunnel release were randomized to receive ultrasound-guided forearm nerve block (n = 50) or forearm IVRA (n = 50). The primary outcome was anaesthetic efficacy evaluated by classifying the blocks as complete vs incomplete. Complete anaesthesia was defined as total sensory block, incomplete anaesthesia as mild pain requiring more analgesics or need of general anaesthesia. Pain intensity on a numeric rating scale (0–10) was recorded. Surgeon satisfaction with hemostasis, surgical time, and OR stay time were recorded. Patient satisfaction with the quality of the block was assessed at POD 1.

Results

In total, 43 (86%) of the forearm nerve blocks were evaluated as complete, compared to 33 (66%) of the forearm IVRA (p = 0.019). After the forearm nerve block, pain intensity was lower at discharge (-1.76 points lower, 95% CI (-2.92, -0.59), p = 0.0006) compared to patients treated with forearm IVRA. No differences in pain experienced at the start of the surgery, during surgery, and at POD1, nor in surgical time or total OR stay were observed between groups. Surgeon (p = 0.0016) and patient satisfaction (p = 0.0023) were slightly higher after forearm nerve block.

Conclusion

An ultrasound-guided forearm nerve block is superior compared to forearm IVRA in providing a surgical block in patients undergoing carpal tunnel release.

Trial registration

This trial was registered as NCT03411551.

WALANT versus intravenous regional anesthesia for carpal tunnel syndrome: a randomized clinical trial

BACKGROUND

There are several anesthetic techniques for surgical treatment of carpal tunnel syndrome (CTS). Results from this surgery using the "wide awake local anesthesia no tourniquet" (WALANT) technique have been described. However, there is no conclusive evidence regarding the effectiveness of the WALANT technique, compared with the usual techniques.

OBJECTIVE

To evaluate the effectiveness of the WALANT technique, compared with intravenous regional anesthesia (IVRA; Bier's block), for surgical treatment of CTS.

DESIGN AND SETTING

Randomized clinical trial, conducted at Hospital Alvorada Moema and the Discipline of Hand Surgery, Universidade Federal de São Paulo (UNIFESP), São Paulo (SP), Brazil.

METHODS

Seventy-eight patients were included. The primary outcome was measurement of perioperative pain through a visual analogue scale (VAS). The secondary outcomes were the Boston Questionnaire score, Hospital Anxiety and Depression Scale (HADS) score, need for use of analgesics, operating room times, remission of paresthesia, failures and complications.

RESULTS

The WALANT technique (n = 40) proved to be superior to IVRA (n = 38), especially for controlling intraoperative pain (0.11 versus 3.7 cm; P < 0.001) and postoperative pain (0.6 versus 3.9 cm; P < 0.001). Patients spent more time in the operating room in the IVRA group (59.5 versus 46 minutes; P < 0.01) and needed to use more analgesics (10.8 versus 5.7 dipyrone tablets; P = 0.02). Five IVRA procedures failed (5 versus 0; P = 0.06).

CONCLUSIONS

The WALANT technique is more effective than IVRA for CTS surgery.

Patient satisfaction with intravenous regional anaesthesia or an axillary block for minor ambulatory hand surgery: A randomised controlled study

BACKGROUND

Intravenous regional anesthesia (IVRA) and the axillary brachial plexus block are popular alternatives to general anaesthesia in ambulatory hand surgery. Although both have proven their effectiveness, patients' preferences have never been evaluated.

OBJECTIVES

We investigated patient satisfaction with both techniques and hypothesised that satisfaction after IVRA is noninferior compared with axillary brachial plexus block.

DESIGN

A prospective, randomised controlled trial.

SETTING

Ambulatory surgical day care centre, University Hospitals of Leuven, Belgium, from September 2016 to November 2017.

PATIENTS

One hundred and twenty adults undergoing minor ambulatory hand surgery were included in this study.

INTERVENTION

Patients received either IVRA with 300 mg lidocaine or an axillary block with 280 mg mepivacaine.

MAIN OUTCOME MEASURES

The primary endpoint was the evaluation of patient satisfaction using the 'Evaluation du Vécu de l'Anésthesie Locoregional' (EVAN-LR) questionnaire. Secondary outcomes included different procedural times, block quality, tourniquet discomfort, the incidence of block failure and postoperative nausea and vomiting (PONV), the severity of postoperative pain and the need for postoperative analgesics during the first 24 h.

RESULTS

Noninferiority of IVRA was shown for the median [IQR] total score on the EVAN-LR questionnaire, IVRA-group: 92 [87 to 96] vs. axillary brachial plexus block-group: 91[87 to 97]; Hodges--Lehmann estimator (95% confidence interval (CI)] for the shift: -0.25 (-2.60 to 2.20). Induction of anaesthesia and time to discharge, requiring partial recovery of the motor block, were significantly longer in the axillary brachial plexus block group. The IVRA-group had a lower block quality, a higher incidence of tourniquet-discomfort and higher median intra-operative and postoperative pain scores on day 0; 0 [0 to 2] vs. 0 [0 to 0] and 0.8 [0 to 1.8] vs. 0 [0 to 0.25], respectively, but no increase in the need for supplementary analgesics or conversion rate to general anaesthesia.

CONCLUSION

IVRA and axillary brachial plexus block result in comparably high patient satisfaction in ambulatory hand surgery.

CLINICAL TRIAL REGISTRATION

EudraCT 2016-002325-11.

[Intravenous regional anesthesia]

OBJECTIVE

Intravenous regional anesthesia.

INDICATIONS

Short duration hand operations.

CONTRAINDICATIONS

Open wounds, lengthy operations, local infections, polyneuropathy, Raynaud syndrome, allergy to local anesthetics.

TECHNIQUE

Insertion of an intravenous cannula, attachment of a double lumen cuff, Esmarch's tourniquet, injection of the local anesthetic, stepwise pumping up the tourniquet, surgery, stepwise removal of the tourniquet.

POSTOPERATIVE MANAGEMENT

Postoperative monitoring of the patient after the end of anesthesia.

RESULTS

Over a time period of 2 years (January 2017-December 2018) 90 operations of the hand were carried out with the patient under intravenous regional anesthesia (IVRA). The average age of the patients was 61 years. After surgery the patients were questioned according to the criteria of the quality of recovery‑9 score according to Myles in the German version of Eberhard et al. (2002). The tourniquet could be removed on average 29 min after surgery. No intraoperative or postoperative complications occurred. Therefore, the IVRA represents a reliable and simple form of anesthesia especially for surgery of the hand.

The analgesic efficacy of intravenous regional anesthesia with a forearm versus conventional upper arm tourniquet: a systematic review

Background

The main objective of this review is to perform a systematic review and meta-analysis of the existing evidence related to the analgesic efficacy with the use of conventional, upper arm intravenous regional anesthesia (IVRA) as compared to a modified, forearm IVRA in adult patients undergoing procedures on the distal upper extremity.

Methods

MEDLINE, EMBASE and CENTRAL (Cochrane) databases were searched for randomized controlled trials published in English, French, Dutch, German or Spanish language. Primary outcomes of interest including description of quality level of anesthesia and onset of sensory block were assessed for this review. Dosage of the local anesthetic, local anesthetic toxicity and need for sedation due to tourniquet pain were considered as secondary outcomes.

Results

Our literature search yielded 3 papers for qualitative synthesis. Four other articles were added into a parallel analysis of 7 reports that provided data on the incidence of complications and success rate after forearm IVRA. Forearm IVRA was found to be as efficient as upper arm IVRA (RR = 0.98 [0.93, 1.05], P = 0.78), but comes with the advantage of a lower need for sedation due to less tourniquet pain.

Conclusion

Our results demonstrate that forearm IVRA is as effective in providing a surgical block as compared to a conventional upper arm IVRA, even with a reduced, non-toxic dosage of local anesthetic. No severe complications were associated with the use of a forearm IVRA. Other benefits of the modified technique include a faster onset of sensory block, better tourniquet tolerance and a dryer surgical field.

Registration of the systematic review

A review protocol was published in the PROSPERO register in November 2015 with registration number CRD42015029536.

Effectiveness of ultrasonography and nerve conduction studies in the diagnosing of carpal tunnel syndrome: clinical trial on accuracy

BACKGROUND

The aim of this study was to evaluate the effectiveness of two diagnostic tests routinely used for diagnosing carpal tunnel syndrome (CTS)-ultrasonography (US) and nerve conduction studies (NCS)-by comparing their accuracy based on surgical results, with the remission of paresthesia as the reference standard.

METHODS

We enrolled 115 patients, all of the female gender with a high probability of a clinical diagnosis of CTS. All patients underwent US and NCS for a diagnosis and subsequent surgical treatment. As a primary outcome, the accuracy of the US and NCS diagnoses was measured by comparing their diagnoses compared with those determined by the surgical outcomes. Their accuracy was secondarily evaluated based on before and after scores of the Boston Carpal Tunnel Questionnaire (BCTQ).

RESULTS

Overall, 104 patients (90.4%) were diagnosed with CTS by the surgical reference standard, 97 (84.3%) by NCS, and 90 (78.3%) by US. The concordance of NCS and surgical treatment (p < 0.001; kappa = 0.648) was superior to that of US and surgical treatment (p < 0.001; kappa = 0.423). The sensitivity and specificity of US and NCS were similar (p = 1.000 and p = 0.152, respectively: McNemar's test). The BCTQ scores were lower after surgery in patients diagnosed by both US and NCS (p < 0.001and p < 0.001, respectively: analysis of variance).

CONCLUSIONS

US and NCS effectively diagnosed CTS with good sensitivity but were not effective enough to rule out a suspicion of CTS.

TRIAL REGISTRATION

This study was registered at September, 10 th, 2015, and the registration number was NCT02553811 .

Comparison of Magnesium Sulfate and Tramadol as an Adjuvant to Intravenous Regional Anesthesia for Upper Extremity Surgeries

BACKGROUND

Intravenous Regional Anesthesia (IVRA) is a simple efficient method for providing regional anesthesia of the limbs. However, it has some limitations such as lack of postoperative analgesia.

OBJECTIVES

This study aimed to compare the analgesic effects of magnesium sulfate and tramadol when added to lidocaine used for IVRA in upper limb surgery.

METHODS

In this double - blind randomized clinical trial, 69 patients who underwent elective upper limb surgery with IVRA were randomly allocated into 3 groups. Patients in group A, received IVRA with 0.5% lidocaine and tramadol 100 mg, in group B received IVRA with 0.5% lidocaine and magnesium sulfate 1.5 g, while in group C patients received IVRA with 0.5% lidocaine and normal saline. The onset of sensory block and the duration of postoperative analgesia pain intensity were noted in each patient. Furthermore, the incidence of postoperative nausea and vomiting, respiratory depression, and skin rash were recorded.

RESULTS

Duration of postoperative analgesia was more prolong in the tramadol group than other groups (P = 0.01). Also, the total amount of morphine consumption in the group A, group B, and C was 8.91 ± 5.81, 11.95 ± 4.81, 16.72 ± 4.07 mg, respectively, which was significantly lower in the tramadol group in comparison to the other groups (P = 0.01).

CONCLUSIONS

It seems that adding tramadol as an adjuvant to lidocaine during IVRA in comparison to magnesium sulfate increases duration of postoperative analgesia and decreases analgesic consumption without increasing opioid-related side effects.

A Study on the Efficacy of the Addition of Low Dose Dexmedetomidine as an Adjuvant to Lignocaine in Intravenous Regional Anaesthesia (IVRA)

INTRODUCTION

Intravenous Regional Anaesthesia (IVRA) is a simple, effective method of providing anaesthesia for short duration surgical procedures on the extremities, its chief drawbacks are tourniquet pain, short duration of block and absence of post-operative analgesia. Dexmedetomidine is known to reduce anaesthetic requirements and also provide analgesia to the patient.

AIM

To evaluate the efficacy of dexmedetomidine as an adjuvant to lignocaine in IVRA with respect to the quality of the block, tourniquet pain and post-operative analgesia.

MATERIALS AND METHODS

A prospective, randomized, double-blinded study was conducted on 60 patients scheduled for orthopaedic surgery of the upper limb, of American Society of Anaesthesiologist's physical status grades I and II. They were divided into two groups of 30 each. The control group C received 40ml of 0.5% lignocaine with saline and Group D received dexmedetomidine 0.5μg/kg added to 40ml of 0.5% lignocaine. The time taken for the onset and recovery of sensory and motor block, incidence of tourniquet pain, intra-operative and post-operative Visual Analogue Scale (VAS) scores, duration of post-operative analgesia and any side effects were noted. Student t-test was used for evaluation of the demographic data, haemodynamic variables, the onset and recovery times of block, duration of analgesia and intra-operative analgesic consumption and tourniquet pain. Friedman's test was used for intra-operative and post-operative VAS and sedation scores.

RESULTS

The onset time of both sensory and motor block were significantly shortened, the recovery of sensory and motor block was prolonged, the incidence of tourniquet pain was comparatively lesser and there was significantly increased duration of post-operative analgesia in the dexmedetomidine group. Haemodynamic parameters were similar in both groups.

CONCLUSION

The addition of 0.5μg/kg of dexmedetomidine as an adjuvant to IVRA effectively enhances the anaesthesia and post-operative analgesia obtained with lignocaine. The low dose of dexmedetomidine was effective and did not cause any major side effects.

Peripheral venous distension elicits a blood pressure raising reflex in young and middle-aged adults

Distension of peripheral veins in humans elicits a pressor and sympathoexcitatory response that is mediated through group III/IV skeletal muscle afferents. There is some evidence that autonomic reflexes mediated by these sensory fibers are blunted with increasing age, yet to date the venous distension reflex has only been studied in young adults. Therefore, we tested the hypothesis that the venous distension reflex would be attenuated in middle-aged compared with young adults. Nineteen young (14 men/5 women, 25 ± 1 yr) and 13 middle-aged (9 men/4 women, 50 ± 2 yr) healthy normotensive participants underwent venous distension via saline infusion through a retrograde intravenous catheter in an antecubital vein during limb occlusion. Beat-by-beat blood pressure, muscle sympathetic nerve activity (MSNA), and model flow-derived cardiac output (Q), and total peripheral resistance (TPR) were recorded throughout the trial. Mean arterial pressure (MAP) increased during the venous distension in both young (baseline 83 ± 2, peak 94 ± 3 mmHg; P < 0.05) and middle-aged adults (baseline 88 ± 2, peak 103 ± 3 mmHg; P < 0.05). MSNA also increased in both groups [young: baseline 886 ± 143, peak 1,961 ± 242 arbitrary units (AU)/min; middle-aged: baseline 1,164 ± 225, peak 2,515 ± 404 AU/min; both P < 0.05]. TPR (P < 0.001), but not Q (P = 0.76), increased during the trial. However, the observed increases in blood pressure, MSNA, and TPR were similar between young and middle-aged adults. Additionally, no correlation was found between age and the response to venous distension (all P > 0.05). These findings suggest that peripheral venous distension elicits a pressor and sympathetic response in middle-aged adults similar to the response observed in young adults.

Comparison of tramadol and lornoxicam in intravenous regional anesthesia: a randomized controlled trial

BACKGROUND AND OBJECTIVES

Tourniquet pain is one of the major obstacles for intravenous regional anesthesia. We aimed to compare tramadol and lornoxicam used in intravenous regional anesthesia as regards their effects on the quality of anesthesia, tourniquet pain and postoperative pain as well.

METHODS

After the ethics committee approval 51 patients of ASA physical status I-II aged 18-65 years were enrolled. The patients were divided into three groups. Group P (n = 17) received 3mg/kg 0.5% prilocaine; group PT (n = 17) 3mg/kg 0.5% prilocaine + 2 mL (100mg) tramadol and group PL (n = 17) 3mg/kg 0.5% prilocaine + 2 mL (8 mg) lornoxicam for intravenous regional anesthesia. Sensory and motor block onset and recovery times were noted, as well as tourniquet pains and postoperative analgesic consumptions.

RESULTS

Sensory block onset times in the groups PT and PL were shorter, whereas the corresponding recovery times were longer than those in the group P. Motor block onset times in the groups PT and PL were shorter than that in the group P, whereas recovery time in the group PL was longer than those in the groups P and PT. Tourniquet pain onset time was shortest in the group P and longest in the group PL. There was no difference regarding tourniquet pain among the groups. Group PL displayed the lowest analgesic consumption postoperatively.

CONCLUSION

Adding tramadol and lornoxicam to prilocaine for intravenous regional anesthesia produces favorable effects on sensory and motor blockade. Postoperative analgesic consumption can be decreased by adding tramadol and lornoxicam to prilocaine in intravenous regional anesthesia.

[Comparison of tramadol and lornoxicam in intravenous regional anesthesia: a randomized controlled trial]

BACKGROUND AND OBJECTIVES

Tourniquet pain is one of the major obstacles for intravenous regional anesthesia. We aimed to compare tramadol and lornoxicam used in intravenous regional anesthesia as regards their effects on the quality of anesthesia, tourniquet pain and postoperative pain as well.

METHODS

After the ethics committee approval 51 patients of ASA physical status I-II aged 18-65 years were enrolled. The patients were divided into three groups. Group P (n=17) received 3mg/kg 0.5% prilocaine; group PT (n=17) 3mg/kg 0.5% prilocaine+2mL (100mg) tramadol and group PL (n=17) 3mg/kg 0.5% prilocaine+2mL (8mg) lornoxicam for intravenous regional anesthesia. Sensory and motor block onset and recovery times were noted, as well as tourniquet pains and postoperative analgesic consumptions.

RESULTS

Sensory block onset times in the groups PT and PL were shorter, whereas the corresponding recovery times were longer than those in the group P. Motor block onset times in the groups PT and PL were shorter than that in the group P, whereas recovery time in the group PL was longer than those in the groups P and PT. Tourniquet pain onset time was shortest in the group P and longest in the group PL. There was no difference regarding tourniquet pain among the groups. Group PL displayed the lowest analgesic consumption postoperatively.

CONCLUSION

Adding tramadol and lornoxicam to prilocaine for intravenous regional anesthesia produces favorable effects on sensory and motor blockade. Postoperative analgesic consumption can be decreased by adding tramadol and lornoxicam to prilocaine in intravenous regional anesthesia.

The efficacy of different doses of Midazolam added to Lidocaine for upper extremity Bier block on the sensory and motor block characteristics and postoperative pain

Objective:

This study was designed to evaluate the effect of different doses of midazolam on anesthesia and analgesia quality when added to lidocaine during the intravenous regional anesthesia (IVRA).

Methods:

One hundred and forty patients underwent hand surgery were randomly allocated into four groups to receive 3 mg/kg lidocaine 2% diluted with saline to a total volume of 40 mL in the control Group L-C (n = 35), 30 μg/kg midazolam plus 3 mg/kg lidocaine 2% diluted with saline to a total volume of 40 mL in the midazolam Group L-M₁ (n = 35), 40 μg/kg midazolam plus 3 mg/kg 2% lidocaine diluted with saline to a total volume of 40 mL in the midazolam Group L-M₂ (n = 35), and 50 μg/kg midazolam plus 3 mg/kg lidocaine 2% diluted with saline to a total volume of 40 mL in the midazolam Group L-M₃ (n = 35). Sensory and motor block and recovery times, tourniquet pain, intra-operative analgesic requirement, and visual analog scale (VAS) scores were recorded.

Findings:

Onset time of sensory and motor block in L-M₃ Group was shorter than the L-M₂ and L-M₁ and L-C Groups (P < 0.001). Furthermore, prolonged sensory (P = 0.005) and motor recovery time (P = 0.001) in L-M₃ were longer than the other groups. Intra-operative VAS score and intra-operative fentanyl consumption in L-M₃ were lower than the other groups (P < 0.001). The numbers of patients needed to pethidine in Group L-M₃ were significantly less compared with the other groups (P = 0.035). VAS scores were significantly lower in Group L-M₃ in different time intervals in the postoperative period compared with the other groups (P < 0.001).

Conclusion:

Addition of 50 μg/kg midazolam for IVRA (Group L-M₃) enhanced intra-operative analgesia and improved anesthesia quality better than other groups receiving lower midazolam doses as well as a control group.

Pain management strategies in hand surgery

Modern anesthetic agents have allowed for the rapid expansion of ambulatory surgery, particularly in hand surgery. The choice between general anesthesia, peripheral regional blocks, regional intravenous anesthesia (Bier block), local block with sedation, and the recently popularized wide-awake hand surgery depends on several variables, including the type and duration of the procedure and patient characteristics, coexisting conditions, location, and expected length of the procedure. This article discusses the various perioperative and postoperative analgesic options to optimize the hand surgical patients' experience.

A comparative evaluation of magnesium sulphate and nitroglycerine as potential adjuncts to lidocaine in intravenous regional anaesthesia

Introduction:

This randomized control trial was carried out to evaluate and compare the efficacy of magnesium sulphate and nitroglycerine (NTG) as adjuncts to lidocaine in intravenous regional anesthesia (IVRA).

Materials and Methods:

Seventy-five, ASA grade I and II patients, aged between 20–50 years, scheduled for hand and forearm surgery were selected and entered randomly into three study groups. Patients in group C received 3 mg/kg of preservative free lidocaine 2% diluted with saline to a total volume of 40 ml. Patients in group M received 3 mg/kg of preservative free lidocaine 2% mixed with 6 ml of 25% magnesium sulphate (1.5 g) diluted with saline to a total volume of 40 ml. Patients in group N received 3 mg/kg of preservative free lidocaine 2% mixed with 200 μg of nitroglycerine diluted with saline to a total volume of 40 ml. Sensory and motor block onset and recovery time, tourniquet pain onset time, intraoperative fentanyl requirement, the total number of patients requiring rescue analgesia and the time to first analgesia requirement, intra-operative and postoperative degree of analgesia were evaluated.

Results:

The sensory and motor block onset times were shorter in group M and N as compared to group C (P- = 0.004, 0.0036 for sensory block, 0.021, 0.038 for motor block. The mean time of onset of sensory block was earliest in group M and the mean time of onset of motor block was earliest in group N. Mean time of onset of tourniquet pain in the three groups was similar in groups M and N. The sensory and motor block recovery time were significantly prolonged in M and N group as compared to group C (P < 0.001). Intraoperative fentanyl requirement (P value– = 0.041), the total number of patients requiring rescue analgesia (P value = 0.009) and the time to first analgesia requirement (P value = 0.038) were lower in group M.

Conclusion:

The addition of both magnesium suphate and nitroglycerin (NTG) to lidocaine for intravenous regional anesthesia (IVRA) leads to early onset of sensory block and prolonged postoperative analgesia, with no side effects.

Comparison of lornoxicam and fentanyl when added to lidocaine in intravenous regional anesthesia

BACKGROUND AND OBJECTIVES

In this study, our goal was to compare intraoperative and postoperative analgesic effects of lornoxicam and fentanyl when added to lidocaine Intravenous Regional Anesthesia (IVRA) in a group of outpatients who underwent hand surgery.

METHODS

This is a double blind randomized study. A total of 45 patients were included, randomized into three groups. Patients in Group I (L) received 3 mg.kg-1 of 2% lidocaine 40 mL; patients in Group II (LL) received 3 mg.kg-1 lidocaine 38 mL + 2 mL lornoxicam; patients in Group III (LF) received 3 mg.kg-1 lidocaine 38 mL + 2 mL fentanyl. Our primary outcome was fi rst analgesic requirement time at postoperative period.

RESULTS

Lornoxicam added to lidocaine IVRA increased the sensory block recovery time without increasing side effects and increased fi rst analgesic requirement time at the postoperative period when compared to lidocaine IVRA (p < 0.001, p < 0.001 respectively) and fentanyl added to lidocaine IVRA (p < 0.001, p < 0.001 respectively). In addition, we also found that fentanyl decreased tourniquet pain (p < 0.01) when compared to lidocaine but showed similar analgesic effect with lornoxicam (p > 0.05) although VAS scores related to tourniquet pain were lower in fentanyl group. Lornoxicam added to lidocaine IVRA was not superior to lidocaine IVRA in decreasing tourniquet pain.

CONCLUSIONS

Addition of fentanyl to lidocaine IVRA seems to be superior to lidocaine IVRA and lornoxicam added to lidocaine IVRA groups in decreasing tourniquet pain at the expense of increasing side effects. However, lornoxicam did not increase side effects while providing intraoperative and postoperative analgesia. Therefore, lornoxicam could be more appropriate for clinical use.

[A randomized, double blind comparison of pethidine and ketoprofen as adjuvants for lignocaine in intravenous regional anaesthesia]

BACKGROUND AND OBJECTIVES

A review of all the adjuncts for intravenous regional anaesthesia concluded that there is good evidence to recommend NonSteroidal Anti-Inflammatory agents and pethidine in the dose of 30mg dose as adjuncts to intravenous regional anaesthesia. But there are no studies to compare pethidine of 30mg dose to any of the NonSteroidal Anti-Inflammatory agents.

METHODS

In a prospective, randomized, double blind study, 45 patients were given intravenous regional anaesthesia with either lignocaine alone or lignocaine with pethidine 30mg or lignocaine with ketprofen 100mg. Fentanyl was used as rescue analgesic during surgery. For the first 6h of postoperative period analgesia was provided by fentanyl injection and between 6 and 24h analgesia was provided by diclofenac tablets. Visual analogue scores for pain and consumption of fentanyl and diclofenac were compared.

RESULTS

The block was inadequate for one case each in lignocaine group and pethidine group, so general anaesthesia was provided. Time for the first dose of fentanyl required for postoperative analgesia was significantly more in pethidine and ketoprofen groups compared to lignocaine group (156.7±148.8 and 153.0±106.0 vs. 52.1±52.4min respectively). Total fentanyl consumption in first 6 h of postoperative period was less in pethidine and ketoprofen groups compared to lignocaine group (37.5±29.0 mcg, 38.3±20.8mcg vs. 64.2±27.2mcg respectively). Consumption of diclofenac tablets was 2.4±0.7, 2.5±0.5 and 2.0±0.7 in the control, pethidine and ketoprofen group respectively, which was statistically not significant. Side effects were not significantly different between the groups.

CONCLUSION

Both pethidine and ketoprofen are equally effective in providing postoperative analgesia up to 6h, without significant difference in the side effects and none of the adjuncts provide significant analgesia after 6h.

Comparison of the effects of low volume prilocaine and alkalinized prilocaine for the regional intravenous anesthesia technique in hand and wrist surgery

Aim. Comparing the effectivity of prilocaine and prilocaine alkalinized with 8.4% NaHCO₃ in terms of sensory and motor block onset and termination durations in RIVA technique considering patients' satisfaction and tolerance with application of tourniquet undergoing hand-wrist surgery. Materials and Methods. 64 patients were randomised into two groups. First group (Group P) was administered prilocaine and second group (Group PN) was administered prilocaine + %8.4 NaHCO₃. Sensory and motor block onset and termination times and onset of tourniquet pain were recorded. Results. No significant difference was found between the two groups in terms of onset and termination of sensory block and the onset of motor block. The duration of the motor block was longer in Group PN than in Group P (P < 0.05). Tourniquet pain was more intense in Group P (P = 0.036). In Group PN, the use of additional drugs was recorded at a lower rate and patients' satisfaction was higher than Group P. Conclusion. In the present study, it was established that alkalinization of prilocaine had no effect on the duration of sensory block and it prolonged the duration of motor block, increased patients' satisfaction, and decreased tourniquet pain. It is our suggestion that future studies should be carried out on the issue by using different volumes.

A randomized, double blind comparison of pethidine and ketoprofen as adjuvants for lignocaine in intravenous regional anaesthesia

BACKGROUND AND OBJECTIVES

A review of all the adjuncts for intravenous regional anaesthesia concluded that there is good evidence to recommend NonSteroidal Anti-Inflammatory agents and pethidine in the dose of 30mg dose as adjuncts to intravenous regional anaesthesia. But there are no studies to compare pethidine of 30mg dose to any of the NonSteroidal Anti-Inflammatory agents.

METHODS

In a prospective, randomized, double blind study, 45 patients were given intravenous regional anaesthesia with either lignocaine alone or lignocaine with pethidine 30mg or lignocaine with ketprofen 100mg. Fentanyl was used as rescue analgesic during surgery. For the first 6h of postoperative period analgesia was provided by fentanyl injection and between 6 and 24h analgesia was provided by diclofenac tablets. Visual analogue scores for pain and consumption of fentanyl and diclofenac were compared.

RESULTS

The block was inadequate for one case each in lignocaine group and pethidine group, so general anaesthesia was provided. Time for the first dose of fentanyl required for postoperative analgesia was significantly more in pethidine and ketoprofen groups compared to lignocaine group (156.7±148.8 and 153.0±106.0 vs. 52.1±52.4min respectively). Total fentanyl consumption in first 6h of postoperative period was less in pethidine and ketoprofen groups compared to lignocaine group (37.5±29.0mcg, 38.3±20.8mcg vs. 64.2±27.2mcg respectively). Consumption of diclofenac tablets was 2.4±0.7, 2.5±0.5 and 2.0±0.7 in the control, pethidine and ketoprofen group respectively, which was statistically not significant. Side effects were not significantly different between the groups.

CONCLUSION

Both pethidine and ketoprofen are equally effective in providing postoperative analgesia up to 6h, without significant difference in the side effects and none of the adjuncts provide significant analgesia after 6h.

Does low-level laser therapy enhance the efficacy of intravenous regional anesthesia?

BACKGROUND

The use of intravenous regional anesthesia (IVRA) is limited by pain resulting from the application of tourniquets and postoperative pain.

OBJECTIVE

To assess the efficacy of low-level laser therapy added to IVRA for improving pain related to surgical fixation of distal radius fractures.

METHODS

The present double-blinded, placebo-controlled, randomized clinical trial involved 48 patients who were undergoing surgical fixation of distal radius fractures. Participants were randomly assigned to either an intervention group (n=24), who received 808 nm laser irradiation as 4 J⁄point for 20 s over ipsilateral three nerve roots in the cervical region corresponding to C5-C8 vertebrae, and 808 nm laser irradiation as 0.1 J⁄cm2 for 5 min in a tangential scanning mode over the affected extremity; or a control group (n=24), who underwent the same protocol and timing of laser probe application with the laser switched off. Both groups received the same IVRA protocol using 2% lidocaine.

RESULTS

The mean visual analogue scale scores were significantly lower in the laser-assisted group than in the lidocaine-only group on all measurements during and after operation (P<0.05). The mean time to the first need for fentanyl administration during the operation was longer in the laser group (P=0.04). The total amount of fentanyl administered to patients was significantly lower in the laser-assisted group (P=0.003). The laser group needed significantly less pethidine for pain relief (P=0.001) and at a later time (P=0.002) compared with the lidocaine-only group. There was no difference between the groups in terms of mean arterial pressure and heart rate.

CONCLUSION

The addition of gallium-aluminum-arsenide laser irradiation to intravenous regional anesthesia is safe, and reduces pain during and after the operation.

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.

A triple-masked, randomized controlled trial comparing ultrasound-guided brachial plexus and distal peripheral nerve block anesthesia for outpatient hand surgery

Background. For hand surgery, brachial plexus blocks provide effective anesthesia but produce undesirable numbness. We hypothesized that distal peripheral nerve blocks will better preserve motor function while providing effective anesthesia. Methods. Adult subjects who were scheduled for elective ambulatory hand surgery under regional anesthesia and sedation were recruited and randomly assigned to receive ultrasound-guided supraclavicular brachial plexus block or distal block of the ulnar and median nerves. Each subject received 15 mL of 1.5% mepivacaine at the assigned location with 15 mL of normal saline injected in the alternate block location. The primary outcome (change in baseline grip strength measured by a hydraulic dynamometer) was tested before the block and prior to discharge. Subject satisfaction data were collected the day after surgery. Results. Fourteen subjects were enrolled. Median (interquartile range [IQR]) strength loss in the distal group was 21.4% (14.3, 47.8%), while all subjects in the supraclavicular group lost 100% of their preoperative strength, P = 0.001. Subjects in the distal group reported greater satisfaction with their block procedures on the day after surgery, P = 0.012. Conclusion. Distal nerve blocks better preserve motor function without negatively affecting quality of anesthesia, leading to increased patient satisfaction, when compared to brachial plexus block.

Comparison of the effect of lidocaine adding dexketoprofen and paracetamol in intravenous regional anesthesia

OBJECTIVE

Comparison of dexketoprofen and paracetamol added to the lidocaine in Regional Intravenous Anesthesia in terms of hemodynamic effects, motor and sensorial block onset times, intraoperative VAS values, and analgesia requirements.

METHOD

The files of 73 patients between 18 and 65 years old in the ASA I-II risk group who underwent hand and forearm surgery were analyzed and 60 patients were included in the study. Patients were divided into 3 groups: Group D (n = 20), 3 mg/kg 2% lidocaine and 50 mg/2 mL dexketoprofen trometamol; Group P (n = 20), 3 mg/kg 2% lidocaine and 3 mg/kg paracetamol; Group K (n = 20), 3 mg/kg 2% lidocaine. Demographic data, motor and sensorial block times, heart rate, mean blood pressure, VAS values, and intraoperative and postoperative analgesia requirements were recorded.

RESULTS

Sensorial and motor block onset durations of Group K were significantly longer than other groups. Motor block termination duration was found to be significantly longer in Group D than in Group K. VAS values of Group K were found higher than other groups. There was no significant difference in VAS values between Group D and Group P. Analgesia requirement was found to be significantly more in Group K than in Group P. There was no significant difference between the groups in terms of heart rates and mean arterial pressures.

CONCLUSION

We concluded that the addition of 3 mg/kg paracetamol and 50 mg dexketoprofen to lidocaine as adjuvant in Regional Intravenous Anesthesia applied for hand and/or forearm surgery created a significant difference clinically.

Emulsified isoflurane increases convulsive thresholds of lidocaine and produces neural protection after convulsion in rats

BACKGROUND

Local anesthetic-induced convulsions remain a concern of anesthesiologists when performing regional anesthesia. Our previous study found that the lidocaine requirement for IV regional anesthesia was reduced with coadministration of emulsified isoflurane. We designed this study to examine whether emulsified isoflurane could increase the convulsive threshold of lidocaine and produce protection after a lidocaine-induced convulsion.

METHODS

In experiment 1, the median convulsive dose of lidocaine with or without the addition of emulsified isoflurane was determined using the up-and-down method. In experiment 2, emulsified isoflurane (0.032 mL/kg for isoflurane), midazolam (1.6 mg/kg), 30% Intralipid (solvent of emulsified isoflurane) or saline was infused to treat lidocaine-induced convulsions, respectively. Convulsive behavior was scored by the modified Racine scale. Cognitive function and the pathology of hippocampus cornu ammonis 3 pyramid neurons of rats were evaluated on days 1, 3, 5, and 7 after convulsions.

RESULTS

In experiment 1, the median convulsive dose of lidocaine alone producing convulsions was 18.7 ± 2.6 mg/kg, and it was increased to 22.7 ± 2.6 (P = 0.010) and 26.7 ± 2.6 mg/kg (P < 0.001) with coadministration of emulsified isoflurane at doses of 0.016 and 0.032 mL/kg isoflurane, respectively. In experiment 2, both emulsified isoflurane and midazolam significantly suppressed lidocaine-induced tonic-clonic seizures. Rats treated with emulsified isoflurane regained full consciousness (convulsive score = 0) significantly earlier than rats treated with midazolam (8.7 ± 2.4 vs 19.5 ± 3.9 minutes, P < 0.001). Cognitive impairment and hippocampus cornu ammonis 3 pyramid neuron abnormalities were found after convulsions and improved with the administration of both emulsified isoflurane and midazolam.

CONCLUSION

Emulsified isoflurane increased the convulsive threshold of lidocaine and preserved neurological function in rats experiencing lidocaine-induced convulsions.

Comparison of lornoxicam and fentanyl when added to lidocaine in intravenous regional anesthesia

BACKGROUND AND OBJECTIVES

In this study, our goal was to compare intraoperative and postoperative analgesic effects of lornoxicam and fentanyl when added to lidocaine Intravenous Regional Anesthesia (IVRA) in a group of outpatients who underwent hand surgery.

METHODS

This is a double blind randomized study. A total of 45 patients were included, randomized into three groups. Patients in Group I (L) received 3mg.kg(-1) of 2% lidocaine 40 mL; patients in Group II (LL) received 3mg.kg(-1) lidocaine 38 mL + 2 mL lornoxicam; patients in Group III (LF) received 3mg.kg(-1) lidocaine 38 mL + 2 mL fentanyl. Our primary outcome was first analgesic requirement time at postoperative period.

RESULTS

Lornoxicam added to lidocaine IVRA increased the sensory block recovery time without increasing side effects and increased first analgesic requirement time at the postoperative period when compared to lidocaine IVRA (p < 0.001, p < 0.001 respectively) and fentanyl added to lidocaine IVRA (p < 0.001, p < 0.001 respectively). In addition, we also found that fentanyl decreased tourniquet pain (p < 0.01) when compared to lidocaine but showed similar analgesic effect with lornoxicam (p > 0.05) although VAS scores related to tourniquet pain were lower in fentanyl group. Lornoxicam added to lidocaine IVRA was not superior to lidocaine IVRA in decreasing tourniquet pain.

CONCLUSIONS

Addition of fentanyl to lidocaine IVRA seems to be superior to lidocaine IVRA and lornoxicam added to lidocaine IVRA groups in decreasing tourniquet pain at the expense of increasing side effects. However, lornoxicam did not increase side effects while providing intraoperative and postoperative analgesia. Therefore, lornoxicam could be more appropriate for clinical use.

Choice of loco-regional anesthetic technique affects operating room efficiency for carpal tunnel release

Intravenous regional anesthesia (Bier block) is indicated for minor procedures such as carpal tunnel release but must be performed in the operating room. We hypothesize that preoperative peripheral nerve blocks decrease anesthesia-controlled time compared to Bier block for carpal tunnel release. With IRB approval, we reviewed surgical case data from a tertiary care university hospital outpatient surgery center for 1 year. Unilateral carpal tunnel release cases were grouped by anesthetic technique: (1) preoperative nerve blocks, or (2) Bier block. The primary outcome was anesthesia-controlled time (minutes). Secondary outcomes included surgical time and time for nerve block performance in minutes, when applicable. Eighty-nine cases met criteria for analysis (40 nerve block and 49 Bier block). Anesthesia-controlled time [median (10th-90th percentiles)] was shorter for the nerve block group compared to Bier block [11 (6-18) vs. 13 (9-20) min, respectively; p = 0.02). Surgical time was also shorter for the nerve block group vs. the Bier block group [13 (8-21) and 17 (10-29) min, respectively; p < 0.01), but nerve blocks took 10 (5-28) min to perform. Ultrasound-guided nerve blocks performed preoperatively reduce anesthesia-controlled time compared to Bier block and may be a useful anesthetic modality in some practice environments.

Cross-Sectional Area of the Median Nerve Characterized by Ultrasound in Patients With Carpal Tunnel Syndrome Before and After the Release of the Transverse Carpal Ligament

The objective of this study was to evaluate the cross-sectional area of the median nerve by ultrasonography before and after release of the transverse carpal ligament in patients with carpal tunnel syndrome. An additional goal was to correlate the cross-sectional area following surgery with clinical symptoms. Eighteen patients and 22 wrists were evaluated. All patients underwent Paine’s surgical technique for release of the transverse ligament. Cross-sectional area was calculated from sonograms taken at the pisiform bone level pre- and postsurgery. Postsurgical measurements were made at 4, 8, 12, and 96 weeks. Before surgery, the mean cross-sectional area was 19.7 mm2. The results following surgery were as follows: 4 weeks, 20.1 mm2; 8 weeks, 17.4 mm2; 12 weeks, 15.5 mm2; and 96 weeks, 13.5 mm2. Three patients remained clinically symptomatic at the time of their last follow-up visit. Cross-sectional area of the median nerve tends to increase 4 weeks after surgery for carpal tunnel syndrome, compared with the measurements taken prior to surgery, and then progressively decreases. There was no evidence of postprocedure correlation between the cross-sectional area of the median nerve and clinical symptoms.

Limb venous distension evokes sympathetic activation via stimulation of the limb afferents in humans

We have recently shown that a saline infusion in the veins of an arterially occluded human forearm evokes a systemic response with increases in muscle sympathetic nerve activity (MSNA) and blood pressure. In this report, we examined whether this response was a reflex that was due to venous distension. Blood pressure (Finometer), heart rate, and MSNA (microneurography) were assessed in 14 young healthy subjects. In the saline trial (n = 14), 5% forearm volume normal saline was infused in an arterially occluded arm. To block afferents in the limb, 90 mg of lidocaine were added to the same volume of saline in six subjects during a separate visit. To examine whether interstitial perfusion of normal saline alone induced the responses, the same volume of albumin solution (5% concentration) was infused in 11 subjects in separate studies. Lidocaine abolished the MSNA and blood pressure responses seen with saline infusion. Moreover, compared with the saline infusion, an albumin infusion induced a larger (MSNA: Δ14.3 ± 2.7 vs. Δ8.5 ± 1.3 bursts/min, P < 0.01) and more sustained MSNA and blood pressure responses. These data suggest that venous distension activates afferent nerves and evokes a powerful systemic sympathoexcitatory reflex. We posit that the venous distension plays an important role in evoking the autonomic adjustments seen with postural stress in human subjects.

Contributions of skin and muscle afferent input to movement sense in the human hand

In the stationary hand, static joint-position sense originates from multimodal somatosensory input (e.g., joint, skin, and muscle). In the moving hand, however, it is uncertain how movement sense arises from these different submodalities of proprioceptors. In contrast to static-position sense, movement sense includes multiple parameters such as motion detection, direction, joint angle, and velocity. Because movement sense is both multimodal and multiparametric, it is not known how different movement parameters are represented by different afferent submodalities. In theory, each submodality could redundantly represent all movement parameters, or, alternatively, different afferent submodalities could be tuned to distinctly different movement parameters. The study described in this paper investigated how skin input and muscle input each contributes to movement sense of the hand, in particular, to the movement parameters dynamic position and velocity. Healthy adult subjects were instructed to indicate with the left hand when they sensed the unseen fingers of the right hand being passively flexed at the metacarpophalangeal (MCP) joint through a previously learned target angle. The experimental approach was to suppress input from skin and/or muscle: skin input by anesthetizing the hand, and muscle input by unexpectedly extending the wrist to prevent MCP flexion from stretching the finger extensor muscle. Input from joint afferents was assumed not to play a significant role because the task was carried out with the MCP joints near their neutral positions. We found that, during passive finger movement near the neutral position in healthy adult humans, both skin and muscle receptors contribute to movement sense but qualitatively differently. Whereas skin input contributes to both dynamic position and velocity sense, muscle input may contribute only to velocity sense.

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.

Comparison of the effects of acetaminophen to ketorolac when added to lidocaine for intravenous regional anesthesia

BACKGROUND

This study was done to evaluate the effect on pain relief when acetaminophen was added to lidocaine for intravenous regional anesthesia (IVRA).

METHODS

SIXTY PATIENTS UNDERGOING HAND OR FOREARM SURGERY RECEIVED IVRA WERE ASSIGNED TO THREE GROUPS: Group C received 0.5% lidocaine diluted with 0.9% normal saline to a total volume of 40 ml (n = 20), Group P received 0.5% lidocaine diluted with intravenous acetaminophen 300 mg to a total volume of 40 ml (n = 20) and Group K received 0.5% lidocaine diluted with 0.9% normal saline plus ketorolac 10 mg made up to a total volume of 40 ml (n = 20). Sensory block onset time, tourniquet pain onset time, which was defined as the time from tourniquet application to fentanyl administration for relieving tourniquet pain and amount of analgesic consumption during surgery were recorded. Following deflation of tourniquet sensory recovery time, postoperative pain and quantity of analgesic uses in post-anesthesia care unit were assessed.

RESULTS

Sensory block onset time was shorter in Group P compared to Group C (P < 0.05). Tourniquet pain onset time was delayed in Group P when compared with group C (P < 0.05). Postoperative pain and analgesic consumption were reduced in Group P and Group K compared to Group C (P < 0.001).

CONCLUSIONS

The addition of acetaminophen to lidocaine for IVRA shortens the onset time of sensory block and delays tourniquet pain onset time, but not with ketorolac. Both acetaminophen and ketorolac reduce postoperative pain and analgesic consumption.

Local adenosine receptor blockade accentuates the sympathetic responses to fatiguing exercise

The role adenosine plays in evoking the exercise pressor reflex in humans remains controversial. We hypothesized that localized forearm adenosine receptor blockade would attenuate muscle sympathetic nerve activity (MSNA) responses to fatiguing handgrip exercise in humans. Blood pressure (Finometer), heart rate, and MSNA from the peroneal nerve were assessed in 11 healthy young volunteers during fatiguing isometric handgrip, postexercise circulatory occlusion (PECO), and passive muscle stretch during PECO. The protocol was performed before and after adenosine receptor blockade by local infusion of 40 mg aminophylline in saline via forearm Bier block (regional intravenous anesthesia). In the second experiment, the same amount of saline was infused via the Bier block. After aminophylline, the MSNA and blood pressure responses to fatiguing handgrip, PECO, and passive stretch (all P < 0.05) were significantly greater than during the control condition. Saline Bier block had no similar effects on the MSNA and blood pressure responses. These data suggest that adenosine receptor antagonism in the exercising muscles may accentuate sympathetic activation during fatiguing exercise.

Sympathetic responses during saline infusion into the veins of an occluded limb

Animal studies have shown that the increased intravenous pressure stimulates the group III and IV muscle afferent fibres, and in turn induce cardiovascular responses. However, this pathway of autonomic regulation has not been examined in humans. The aim of this study was to examine the hypothesis that infusion of saline into the venous circulation of an arterially occluded vascular bed evokes sympathetic activation in healthy individuals. Blood pressure, heart rate, and muscle sympathetic nerve activity (MSNA) responses were assessed in 19 young healthy subjects during local infusion of 40 ml saline into a forearm vein in the circulatory arrested condition. From baseline (11.8 +/- 1.2 bursts min(-1)), MSNA increased significantly during the saline infusion (22.5 +/- 2.6 bursts min(-1), P < 0.001). Blood pressure also increased significantly during the saline infusion. Three control trials were performed during separate visits. The results from the control trial show that the observed MSNA and blood pressure responses were not due to muscle ischaemia. The present data show that saline infusion into the venous circulation of an arterially occluded vascular bed induces sympathetic activation and an increase in blood pressure. We speculate that the infusion under such conditions stimulates the afferent endings near the vessels, and evokes the sympathetic activation.

Evaluation of the efficacy of magnesium sulphate as an adjuvant to lignocaine for intravenous regional anaesthesia for upper limb surgery

Several additives have been combined with local anaesthetics for intravenous regional anaesthesia to improve block quality, analgesia and to decrease tourniquet pain. Magnesium sulphate is one potential additive. This prospective, randomised, double-blinded study was conducted in 30 ASA physical status I or II patients undergoing upper limb surgery under tourniquet. In group L, patients received intravenous regional anaesthesia with lignocaine alone (9 ml of 2% lignocaine diluted with normal saline to total volume of 36 ml). Patients in group M received intravenous regional anaesthesia with lignocaine plus magnesium sulphate (6 ml of 25% magnesium sulphate plus 9 ml of 2% lignocaine diluted with normal saline to total volume of 36 ml). Assessment was by observing the response to injection of drug; sensory and motor block and tourniquet pain. The mean time of onset of sensory block was 12.40 and 3.47 minutes in groups L and M respectively (P < 0.001). The average times of onset of motor block in groups L and M were 17 and six minutes respectively (P < 0.001). Of the patients in group M, 66.7% reported moderate to severe pain while the drug was being injected, compared to 20% in group L (P=0.011). There was a statistically significant difference in visual analogue scale for tourniquet pain at 10 and 30 minutes after tourniquet inflation (lower in group M). These findings indicate that magnesium sulphate added as an adjuvant to lignocaine hastens the onset of sensory and motor block and decreases tourniquet pain. However there is increased incidence of transient pain on injection if magnesium sulphate is added.

Comparing the effectiveness of modified forearm and conventional minidose intravenous regional anesthesia for reduction of distal forearm fractures in children

BACKGROUND

Minidose intravenous regional anesthesia (IVRA) and modified forearm IVRA have been used for closed reduction of forearm fractures and for hand surgery in children.

METHODS

Children (5-17 years old) with forearm fractures presenting to a pediatric emergency department were enrolled in a randomized controlled trial to test if modified forearm and minidose IVRA together would provide improved analgesia with reduced risk of anesthetic toxicity compared with conventional minidose IVRA. Pain was assessed using a visual analog scale (FACES) and an objective pain scale (OPS) score at baseline and at critical times. Spearman rank correlation and repeated-measures analysis of variance were used to compare interobserver pain measures and detect differences between the groups over time.

RESULTS

Among the 62 patients in the study, no significant differences were observed between groups in objective measures of blood pressure, oxygen saturation, and heart rate at baseline, 5 minutes after IVRA, during surgical reduction, and 15 minutes after reduction. Nurses reported patients experienced a reduction in pain of 2.5 (SD, 3.1) on FACES and 2.3 (SD, 3.1) on OPS at 5 minutes after sedation (P < 0.001 for both). From time of reduction to 15 minutes after the procedure, FACES score declined 1.7 (SD, 3.4) (P = 0.001), and OPS declined 2.1 (SD, 3.6) (P = 0.002). No significant differences were found between experimental arms.

CONCLUSION

The modified forearm minidose IVRA procedure is an acceptable alternative for the relief of pain that usually accompanies the manipulation and reduction of forearm fractures but does not appear to provide additional pain relief compared with conventional minidose IVRA.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Comparison of forearm and conventional Bier's blocks for manipulation and reduction of distal radius fractures

Forearm-based Bier's block has been advocated as a useful anaesthesic technique in hand surgery. However, there is limited data comparing forearm blocks with the conventional Bier's block. We conducted a randomised controlled trial (n=30) comparing the two techniques of anaesthesia for manipulation and reduction of closed distal radius fractures in an emergency room setting. Pain scores measured using the Visual Analogue Scale during the procedure were used as the primary outcome assessment. There was no significant difference in pain scores between the forearm and conventional Bier's block (mean VAS 18.4 SD 22.10 versus 33.7 SD 29.6). No major complications were observed in either group. The forearm-based Bier block is an effective alternative to the conventional block.

The analgesic effect of lornoxicam when added to lidocaine for intravenous regional anaesthesia

BACKGROUND

The aim of the study was to evaluate the effect of lornoxicam (L) on sensory and motor block onset time, tourniquet pain, and postoperative analgesia, when added to lidocaine in intravenous regional anaesthesia (IVRA).

METHODS

Forty-five patients undergoing hand surgery were randomly and blindly divided into three groups as to receive either i.v. saline and IVRA with lidocaine 0.5% (Control group, n=15), i.v. saline and IVRA lidocaine 0.5% with lornoxicam (L-IVRA group, n=15), or intravenous lornoxicam and IVRA lidocaine 0.5% (L-IV group, n=15). Sensory and motor blocks onset time, and tourniquet pain was measured after tourniquet application at 5, 10, 20, and 30 min, and analgesic use were recorded during operation. After the tourniquet deflation, at 1, 30 min, and 2, 4 h, visual analogue scales score, the time to first analgesic requirement, total analgesic consumption in first 24 h, and side effects were noted.

RESULTS

Sensory and motor block onset times were shorter and the recovery time prolonged in the Group L-IVRA compared with the other group (P=0.001). A decreased tourniquet pain, a prolonged time first analgesic requirement [229 (85) min vs 28 (20) and 95 (24) min, P=0.0038) and less postoperative analgesic requirements during 24 h were found in Group L-IVRA compared with the other groups (P<0.05).

CONCLUSIONS

The addition of lornoxicam to lidocaine for intravenous regional anaesthesia shortens the onset of sensory and motor block, decreases tourniquet pain and improves postoperative analgesia without causing any side effect.

The Analgesic Effect of Nitroglycerin Added to Lidocaine on Intravenous Regional Anesthesia

We evaluated the analgesic effect of nitroglycerine (NTG) when added to lidocaine in IV regional anesthesia. Thirty patients undergoing hand surgery were randomly assigned to two groups. The control group (group C, n = 15) received a total dose of 40 mL with 3 mg/kg of lidocaine diluted with saline, and the NTG group (group NTG, n = 15) received an additional 200 mug NTG. Hemodynamic variables, tourniquet pain measured before and 1, 5, 10, 20, and 30 min after tourniquet inflation, and analgesic requirements were recorded during the operation. After the tourniquet deflation, at 1 and 30 min and 2 and 4 h, visual analog scale (VAS) score, time to first analgesic requirement, total analgesic consumption in the first 24 h after operation, and side effects were noted. Shortened sensory and motor block onset time (3.2 +/- 1.1 versus 4.5 +/- 1.2 min; P = 0.01 and 3.3 +/- 1.6 versus 5.2 +/- 1.8; P = 0.009 in group NTG and group C, respectively), prolonged sensory and motor block recovery times (6.8 +/- 1.6 versus 3.1 +/- 1.2 min P < 0.0001 and 7.3 +/- 1.3 versus 3.6 +/- 0.8 P < 0.0001 in group NTG and group C, respectively), shortened VAS scores of tourniquet pain (P = 0.023), and improved quality of anesthesia were found in group NTG (P < 0.05). VAS scores were lower in group NTG after tourniquet release and in the postoperative period (P = 0.001). First analgesic requirement time was longer in group NTG (225 +/- 74 min versus 39 +/- 33 min) than in group C (P < 0.0001). Postoperative analgesic requirements were significantly smaller in group NTG (P < 0.0001) but the side effects were similar in both groups. We conclude that the addition of NTG to lidocaine for IV regional anesthesia improves sensory and motor block, tourniquet pain, and postoperative analgesia without side effects.