Perivascular Axillary Block V: Blockade following 60 ml of Mepivacaine 1 % Injected as a Bolus or as 30 + 30 ml with a 20-min Interval

Perivascular axillary blockade was performed on 60 patients with the aid of a catheter technique. The patients were randomly allocated to two groups. All patients received the same dose of local anaesthetic: 60 ml of mepivacaine 1% with adrenaline, but one group received the dose as a bolus injection, whereas the other group received the dose as fractional injections of 30 + 30 ml with an interval of 20 min. Blood concentrations of mepivacaine were measured up to 90 min after injection of local anaesthetic. Sensory and motor blockade were evaluated 20, 30 and 40 min after injection. Forty minutes after the last injection of local anaesthetic, there was no difference between the blockades of the two groups, except for the sensory blockade of the lower lateral cutaneous nerve of the arm, in which the frequency of analgesia was 90% after bolus injection and 63% after fractional injections. There was no difference in blood concentrations of mepivacaine between the two groups. None of the 60 patients showed any sign of systemic toxic reactions. Fractional injection of local anaesthetic in perivascular axillary blockade does not offer any advantage over bolus injection with regard to the resulting blockade.     

Perivascular Axillary Block IV: Blockade Following 40, 50 or 60 ml of Mepivacaine 1 % with Adrenaline

Perivascular axillary blockade was performed on 90 patients with the aid of a catheter technique. The patients were randomly allocated to receive either 40, 50 or 60 ml of 1% mepivacaine with adrenaline 1:200,000. Blood concentrations of mepivacaine were measured up to 90 min after injection in seven, eight and ten of the patients from the three groups. Sensory and motor blockade was evaluated 20, 30 and 40 min after injection. All groups showed the same temporal development of the blockade, i.e. improval of the blockade during the period from 20 to 40 min after injection, but no difference was found in the sensory or motor blockade between the three groups. However, a further analysis of the incomplete blockades showed a better quality of the sensory blockade in the groups given 50 and 60 ml than in the group given 40 ml. None of the 90 patients showed any signs of systemic toxic reactions. The mean peak values of blood concentrations were 0.5-1.0 microgram/ml higher in the groups given 50 ml and 60 ml than in the group given 40 ml. On the basis of the present and two previous investigations on the dose response in perivascular axillary blockade, a dose of 50 ml 1% mepivacaine with adrenaline or another equivalent drug with vasoconstrictor is recommended.     

Peri vascular axillary block VII: the effect of a supplementary dose of 20 ml mepivacaine 1 % with adrenaline to patients with incomplete sensory blockade

Perivascular axillary blockade was performed on 233 patients with the aid of a catheter technique. All patients received a primary injection of 50 ml of mepivacaine 1% with adrenaline. Sensory blockade was evaluated 20, 30 and 40 min after injection, and a complete sensory blockade was found in 90 (39%), 131 (57%) and 146 (63%), respectively. The blockade effect of a supplementary perivascular injection of 20 ml of the same agent was investigated on the remaining 87 blockades, which could be divided into three categories: blockades which at 20 min showed lack of analgesia in several cutaneous segments of the hand (34 patients); blockades which at 30 min showed a total lack of sensory blockade within a limited area (29 patients); and blockades which at 40 min showed signs of blockade of all cutaneous segments, but one or several segments were not blocked with an intensity compatible with surgery (24 patients). Blockades of categories 1 and 2 were at 20 and 30 min, respectively, randomly allocated to control or to perivascular supplementation groups, while blockades of category 3 all had supplementation at 40 min. Sensory blockade was reevaluated 10 and 20 min after group allocation, and it was found that perivascular supplementation had no significant effect on the sensory blockade in category 1 and 2, while 68% of the blockades in category 3 improved to a complete blockade.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparative study between 5% prilocaine and 2% mepivacaine by the subarachnoid route in transurethral resections

OBJECTIVE: To compare the duration of spinal block with 5% prilocaine and 2% mepivacaine in short procedures for transurethral resection and to assess possible complications in the immediate postoperative period. MATERIAL AND METHODS: Fifty-seven patients scheduled for transurethral resection of the prostate or a vesical tumor. Patients were ASA I-III, over 55 years of age and randomly assigned to two groups to receive 5% prilocaine (1 mg/kg, n = 27) or 2% mepivacaine (0.8 mg/kg, n = 30). We collected data on anesthetic technique, levels of extension of motor and sensory blockades, duration of blockades and complications within the first 24 hours after surgery. RESULTS: Demographic data, ASA classification and duration of surgery were similar in both groups. We found statistically significant differences (p < 0.05) in duration of sensory blockade (120.92 +/- 36.21 min with prilocaine and 145.83 +/- 35.81 min with mepivacaine) and in motor blockade (106.29 +/- 38.16 min with prilocaine and 133.16 +/- 42.21 min with mepivacaine). Five cases of hypotension and 4 of bradycardia occurred in each group and one patient in the mepivacaine group suffered slight postoperative cephalea. CONCLUSIONS: Both local anesthetics offer good surgical conditions with hemodynamic stability and few complications. The duration of sensory and motor blockade is shorter with prilocaine than with mepivacaine, making prilocaine more appropriate for short interventions.     

Perivascular Axillary Block II: Influence of Injected Volume of Local Anaesthetic on Neural Blockade

Perivascular axillary blockade was performed on 150 patients with the aid of a catheter technique. Blockade failure due to injection outside the neurovascular sheath was found in 5.7% of the subject material. The patients were randomly allocated to three groups. The amount of local anaesthetic was constant in each group: 400 mg mepivacaine with adrenaline. However, the injected volume was a variable factor, namely 20, 40 or 80 ml. Sensory and motor blockade was tested 30 min after each injection. The following results were obtained: 1) Apart from the axillary, musculocutaneous and radial nerves, a high frequency of analgesia was found in all cutaneous areas (over 85%). 2) In the axillary area, improvements were found with increasing volume. 3) Analgesia in the musculocutaneous area occurred in 52% of the patients in group 1 (20 ml) and improved to 75% in group 2 (40 ml). However, no difference was found between group 2 and group 3 (80 ml). 4) Volume had no influence on analgesia in the radial area. 5) Motor blockade was intensified with decreasing volume, i.e. with an increase of concentration of local anaesthetic solution.     

Perivascular Axillary Block I: Blockade Following 40 ml 1 % Mepivacaine with Adrenaline

Perivascular axillary block was performed on 80 patients by a catheter technique. All patients had a standard dose of 40 ml mepivacaine 1% with adrenaline. Thirty minutes after the injection, the motor and sensory blockade was determined. Eighty-six pet cent of the patients had a distinct motor blockade, whereas the remaining 14% had only a slight motor blockade. The sensory blockade was complete in 63%, whereas 37% had lack of analgesia in one or several cutaneous areas. Lack of analgesia was most often found in the cutaneous area of the axillary, musculocutaneous and radial nerves. The frequency of analgesia in the three areas of innervation was analysed with reference to the influence of the age, height and weight of the patient, and of differences in technique: paraesthesias, position of catheter, and unintended puncture of blood vessels. None of these variables seems to be important for the low frequency of analgesia in the three areas of innervation.     

High dose spinal anaesthesia with glucose free 0.5% bupivacaine 25 and 30 mg

The purpose of this study was to investigate if a more intense and/or prolonged blockade could be obtained safely when a high-dose intrathecal plain bupivacaine was given.
Thirty patients for elective surgery were included. Two groups of 15 patients, received 25 or 30 mg 0.5% bupivacaine (plain). The sensory and motor blockade was determinated. Heart rate and respiratory frequency was monitored continuously, arterial blood pressure every 5 minutes. Peak expiratory flow (PEF) was performed before, and 45 min after the spinal injection.
In group 25 mg the maximal spread of analgesia was to T3.7±0.9 (mean±s.e.mean) after 45 minutes, in group 30 mg 13.1 ±0.4 also after 45 min (NS). The maximal extent of analgesia was retained for a significantly longer period and the initial decline in extent of analgesia was significantly slower in the 30 mg group. No significant difference as to duration of motor blockade was found. Peak expiratory flow diminished significantly 45 min after the spinal injection in both groups, but no significant difference was found between the groups. The total duration of analgesia did not differ significantly between the groups.
A significantly longer duration of maximal cephalad spread, and a slower initial regression, was found in the 30 mg group. No severe uncontrolled haemodynamic or respiratory side effects occurred.     

Epidural anaesthetic effect of the 8% emulsified isoflurane: a study in rabbits

BACKGROUND: Studies have shown that local use of volatile anaesthetics produce local anaesthetic effects such as local infiltration anaesthesia (in rats and humans) and spinal anaesthesia (in dogs). However, there is still no report on the epidural anaesthetic effect of volatile anaesthetics. The aim of the present study was to evaluate the epidural anaesthetic effect of the 8% emulsified isoflurane in rabbits. METHODS: Forty rabbits chronically instrumented with an epidural catheter were randomly divided into four groups of 10 rabbits each. According to group assignment, rabbits received epidural administration of 8% emulsified isoflurane (v/v) 1 ml in the E-isoflurane group, 1% lidocaine 1 ml in the Lidocaine group, 30% lipid emulsion 1 ml in the Itralipid group, or normal saline 1 ml in the NS group. The sensory and motor functions and the state of consciousness were assessed at baseline and at predetermined regular intervals. Then, the rabbits were continuously observed for 2 weeks to examine the possible long-term neurological complications. RESULTS: The sensory blockade onset time, motor blockade onset time, and motor blockade duration in the E-isoflurane group [1.4 (0.7), 1.6 (0.7), and 34 (10) min, respectively] were similar to those in the Lidocaine group [1.3 (0.5), 1.7 (0.8), and 38 (8), min, respectively]. The sensory blockade duration in the E-isoflurane group was longer than that in the Lidocaine group [68 (13) vs 49 (13) min, P<0.01]. No epidural anaesthetic effects occurred in the NS group and the Intralipid group. None of the rabbits showed an abnormal consciousness after the epidural drug administration. None of the rabbits showed any long-term neurological deficits during a 2 week observation. CONCLUSIONS: The present study demonstrates that epidural administration of the 8% emulsified isoflurane produces completely a reversible epidural anaesthetic effect that does not affect the level of consciousness in rabbits.     

Lumbar plexus and sciatic nerve block for knee arthroplasty: comparison of ropivacaine and bupivacaine

PURPOSE: Information about the onset time and duration of action of ropivacaine during a combined lumbar plexus and sciatic nerve block is not available. This study compares bupivacaine and ropivacaine to determine the optimal long-acting local anaesthetic for lumbar plexus and sciatic nerve block in patients undergoing total knee arthroplasty. METHODS: Forty adult patients scheduled for unilateral total knee arthroplasty, under lumbar plexus and sciatic block were entered into this double-blind randomized study. Patients were assigned (20 per group) to receive lumbar plexus block using 30 ml of local anaesthetic and a sciatic nerve block using 15 ml of local anaesthetic with either bupivacaine 0.5% or ropivacaine 0.5%. All solutions contained fresh epinephrine in a 1:400,000 concentration. Every one minute after local anaesthetic injection, patients were assessed to determine loss of motor function and loss of pinprick sensation in the L1-S1 dermatomes. The time to request first analgesic was documented from the PCA pump. This time was used as evidence of block regression. RESULTS: Blocks failed in four patients in each group. The mean onset time of both motor and sensory blockade was between 14 and 18 min in both groups. Duration of sensory blockade was longer in the bupivacaine group, 17 +/- 3 hr, than in the ropivacaine group, 13 +/- 2 hr (P < 0.0001). CONCLUSION: We conclude that bupivacaine 0.5% and ropivacaine 0.5% have a similar onset of motor and sensory blockade when used for lumbar plexus and sciatic nerve block. Analgesic duration from bupivacaine 0.5% was prolonged by four hours compared with an equal volume of ropivacaine 0.5%.     

The effects of clonidine on ropivacaine 0.75% in axillary perivascular brachial plexus block

INTRODUCTION: The new long-acting local anesthetic ropivacaine is a chemical congener of bupivacaine and mepivacaine. The admixture of clonidine to local anesthetics in peripheral nerve block has been reported to result in a prolonged block. The aim of the present study was to evaluate the effects of clonidine added to ropivacaine on onset, duration and quality of brachial plexus block. METHODS: Patients were randomly allocated into two groups. In group I brachial plexus was performed using 40 ml of ropivacaine 0.75% plus 1 ml of NaCL 0.9%, and in group II brachial plexus was performed using 40 ml of ropivacaine 0.75% plus 1 ml (0.150 mg) of clonidine. Onset of sensory and motor block of radial, ulnar, median and musculocutaneous nerve were recorded. Motor block was evaluated by quantification of muscle force, according to a rating scale from 6 (normal contraction force) to 0 (complete paralysis). Sensory block was evaluated by testing response to a pinprick in the associated innervation areas. Finally, the duration of the sensory block was registered. Data were expressed in mean+/-SD. For statistical analysis a Student t-test was used. A P-value of < or = 0.05 was considered as statistically significant. RESULTS: The duration of blockade was without significant difference between the groups. Group I: 718+/-90 min; Group II: 727+/-117 min. There was no intergroup difference in sensory and motor onset or in quality of blockade. CONCLUSION: The addition of clonidine to ropivacaine 0.75% does not lead to any advantage of block of the brachial plexus when compared with pure ropivacaine 0.75%.     

No difference between bupivacaine in 0.9% and 8% glucose for spinal anaesthesia in small children

BACKGROUND: Baricity is one of the most important factors to influence the characteristics of distribution of the local anaesthetic and hence success and spread of the blockade. Bupivacaine is rendered hyperbaric by adding glucose. The effect of differing degrees of hyperbaricity remains to be evaluated. METHODS: Two hyperbaric bupivacaine solutions, in 0.9% and in 8% glucose, for spinal anaesthesia were investigated in 60 children, aged 1-7 years, in a double-blind, randomised, parallel group, prospective study. The children were premedicated with diazepam orally. Bupivacaine 5 mg ml(-1) in either 0.9% or 8% glucose was injected in a dose of 0.4 mg kg(-1). Maximum cephalad extent and regression of sensory block were tested by transcutaneous electrical stimulation. RESULTS: Success rate, spread and duration of sensory block were similar in both groups. Only one child required a single dose of fentanyl during surgery. The highest median level of sensory block was T3 (T2-T7) (median (10th/90th percentiles)) in both groups. Time to reach T10 did not differ between the groups. The incidence of adverse effects was similar. Atropine was administered to one child in each group to treat bradycardia and 6 children (10%) experienced shivering. One child in each group vomited once. CONCLUSION: These results demonstrate that bupivacaine in 0.9% glucose and in 8% glucose solutions are equally suitable for spinal anaesthesia in small children. Similar success rate, spread and duration of the sensory and motor block are achieved with both baricities of bupivacaine.     

Anesthésie péridurale pour la chirurgie de la cheville et du pied: influence de la position assise

The effects of the sitting position on the quality of both sensory and motor blockade of segments L5 and S1 and the haemodynamic consequences during epidural anaesthesia were studied on 39 patients undergoing ankle or foot surgery. After insertion of an epidural catheter with the patient in the lateral position, 19 patients were kept sitting for 15 min following the injection of the local anaesthetic and 20 remained supine for the duration of anaesthesia (control group). All patients received a dose of 20 ml of 1.73% carbonated lidocaine with epinephrine 1:200,000. The quality and time of onset of the sensory blockade for segments L1-S2 as well as its cephalad spread were comparable in both groups. Fourteen patients of the sitting group achieved motor blockade of more than three of five myotomes compared with five patients in the supine group (P less than 0.001). The maximum decrease in mean arterial pressure occurred sooner in the sitting group (14 +/- 9 min) than in the control group (21 +/- 10 min; P less than 0.01) and was more severe (-24 +/- 10% vs -16 +/- 10% respectively; P less than 0.05). Our results indicate that placing the patient in the sitting position for 15 min after inducing epidural anaesthesia does not influence caudal sensory blockade but does increase the depth of motor blockade.     

Comparison between 1.5% lidocaine with adrenaline and 1.5% plain mepivacaine in axillary brachial plexus block]

OBJECTIVES: To evaluate the distribution of sensory blockade, the onset time and the duration of the axillary plexus block obtained after the administration of 40 mL of 1.5% lignocaine with adrenaline or 40 mL of plain 1.5% mepivacaine. STUDY DESIGN: Prospective, randomised, comparative, double blind study. PATIENTS AND METHODS: One hundred and fifty five patients undergoing hand surgery were randomised into two groups: in group L, 73 patients were given 1.5% lignocaine with 1/200,000 adrenaline and in group M, 82 patients received 1.5% mepivacaine. The entire volume was injected on the first evoked motor activity obtained for a current less than 0.5 mA. Sensory and motor block of each of the four major nerves of the hand and forearm were assessed using light touch and motor strength respectively. The block was considered complete when all nerves were anaesthetised (median, radial, musculocutaneous and ulnar). RESULTS: The percentage of complete sensitive blockade was 22% in group L and 24% in group M. Complete motor blockade was respectively 27% in group L and 40% in group M. The median time required to obtain a complete sensory blockade was 18 min for both group. The median time required to obtain a complete motor blockade was 17 min in-group L and 16 min in-group M. The duration of the sensory blockade was not different for both groups (i.e., 255 +/- 76 min versus 231 +/- 70 min in group L and M respectively. The duration of the motor blockade was longer in group L compared to group M (199 +/- 64 min versus 231 +/- 74 min respectively, p < 0.05). CONCLUSION: Following axillary plexus block, 1.5% mepivacaine improves neither the extension nor the duration of sensory blockade achieved by 1.5% lignocaine with adrenaline.     

Ropivacaine 0.25% compared with bupivacaine 0.25% by the caudal route.

We compared in a randomized double-blind study, the postoperative analgesia and degree of motor block produced by the new local anaesthetic ropivacaine, with bupivacaine, for caudal anaesthesia in children. Eighty children, 2-5-years-old, ASA I, received one of two local anaesthetics; either ropivacaine 0.25% (1.0 ml x kg(-1)) or bupivacaine 0.25% (1.0 ml x kg(-1)). They were sedated with a continuous infusion of propofol (200 microg x kg(-1) min(-1). The lungs were ventilated with a mixture of 50% nitrous oxide with oxygen. 60 min after local anaesthetic injection, and every 60 min, the extent of the motor block in the recovery room was scored as 1-3, according to a modified Bromage scale. Adverse events and the time to the first analgesic requirement were reported. Patients in the two groups did not differ with respect to age, weight and height. There were no differences in heart rate and arterial pressure between the two groups(P>0.05). No adverse events were observed. The ropivacaine group showed a shorter duration of motor block than the bupivacaine group (P<0.05). The first postoperative analgesic requirement was a mean (sd) of 5 h+/-4.32 after the operation in the ropivacaine group and 5 h+/-3.81 for the bupivacaine group. These findings suggest that caudal anaesthesia with ropivacaine 0.25% in paediatric patients can be effective, with less motor blockade in the postoperative period.     

Effects of different glucose concentrations on spinal anaesthesia with bupivacaine and tetracaine

The effects of 5% and 8% glucose in 0.5% tetracaine or bupivacaine on the anaesthetic spread were investigated in 80 urological patients requiring spinal anaesthesia for trans-urethral resection of the prostate. The local anaesthetic solutions were randomly administered, the patients being divided into four groups of 20, and the anaesthetic profile was then evaluated in a double-blind fashion by an independent observer. Maximum cephalad spread of analgesia was significantly greater with tetracaine in 8% glucose compared to the other three groups (tetracaine/5% glucose, bupivacaine/5 or 8% glucose) (P less than 0.05). Glucose concentration significantly influenced spreading characteristics of tetracaine, the 8% solution achieving a higher level in a shorter time than the 5% solution. Sensory regression to both T10 and S1 dermatome was longer with bupivacaine in 8% glucose compared to 5% glucose. The concentration of glucose, however, did not influence the regression of sensory analgesia for tetracaine. Both the 5% and 8% solutions of tetracaine achieved a 3+ motor blockade significantly faster than either bupivacaine solution. Regression of motor blockade from tetracaine was not influenced by the glucose concentration, but the 8% solution of bupivacaine had a delayed 2+ and 3+ blockade, although the ultimate decay for both solutions was similar. The results of our study suggest that 0.5% bupivacaine 4 ml in 5% glucose provides a rapid and controllable spread of sensory analgesia for transurethral surgery, of optimal duration associated with a complete motor blockade of moderate duration.     

Motor blockade and EMG recordings in epidural anaesthesia. A comparison between mepivacaine 2%, bupivacaine 0.5 % and etidocaine 1.5%

In a double-blind study young volunteers randomly received 20 ml of mepivacaine 2%, bupivacaine 0.5% or etidocaine 1.5% epidurally, all solutions with adrenaline. The mean cephalad spread of pin-prick analgesia was equal (T10) in the groups, but the duration was longest for bupivacaine and etidocaine. The motor blockade of the rectus abdominis muscles was assessed quantitatively by rectified integrated electromyographic recordings (RIEMG) and as number of turns in EMG recordings [changes in the direction (rise/fall) of the EMG; TURNS] from three different segmental levels, T7, T9 and T11. The motor blockade of the quadriceps muscles was estimated by EMG recordings simultaneously with muscle force measurements at maximal isometric knee extension. Motor blockade was also evaluated by the Bromage scale. There was good correlation (correlation coefficient 0.91) between RIEMG values and muscle force in knee extension during epidural anaesthesia. TURNS showed a non-linear relationship to isometric force during epidural anaesthesia and added no further information. At the lower parts of the abdomen (T11), etidocaine gave more profound and longer motor blockade than mepivacaine. For quadriceps muscle function, motor blockade was almost complete with all three local anaesthetics; the duration of maximum motor blockade was short (45-60 min) for mepivacaine, but about 5 h with etidocaine. At the time when the Bromage scale indicated complete regression of motor blockade, the muscle force of knee extension was only 30% and the quadriceps RIEMG 35% of control values and 1-3 h remained until the time of mobilization.(ABSTRACT TRUNCATED AT 250 WORDS)     

Motor and sensory blockade after epidural injection of mepivacaine, bupivacaine, and etidocaine--a double-blind study

In a double-blind study of epidural anesthesia, 30 young volunteers were given either 2% mepivacaine (400 mg), 0.5% bupivacaine (100 mg), or 1.5% etidocaine (300 mg), all solutions containing epinephrine (1:200,000). The spread of analgesia was equal in the groups, whereas the longest duration was noted in the etidocaine and bupivacaine groups. With use of a method for determining muscle force, motor blockade during anesthesia was recorded quantitatively for hip flexion, knee extension, and plantar flexion of the big toe. Onset of motor blockade was significantly more rapid with etidocaine than with bupivacaine and mepivacaine. All subjects given etidocaine developed complete motor blockade, but with the other local anesthetics 5%-33% of the initial muscle force remained. The least motor blockade was found in the L5-S2 segment (plantar flexion of the big toe). The duration of maximal motor blockade varied between 60 min (mepivacaine) and 360 min (etidocaine). With each of the three local anesthetics, motor function returned simultaneously in the three muscle groups tested. Complete restoration of muscle function occurred significantly later for etidocaine (600 min) than for bupivacaine (360 min) and mepivacaine (180 min). With etidocaine, the motor blockade outlasted the sensory blockade by 150 min. The Bromage scale corresponded to the motor blockade only during the first half of the regression phase. Not until 1-3 h after attainment of Bromage grade 0 was the muscle force of all movements restored (90% of control values).     

Levobupivacaina,bupivacaina racemica e ropivacaina nel blocco del plesso brachiale

BACKGROUND: To compare clinical profiles of levobupivacaine, racemic bupivacaine and ropivacaine at equipotent doses in axillary brachial plexus block in the orthopaedic surgery of wrist and hand. METHODS: For this prospective, open randomised study we took on 45 patients of both sexes, ASA I-III, subdivided into three groups in which, respectively, axillary brachial plexus block was performed, with ENS, using levobupivacaine 0.50% (1 mg/kg), racemic bupivacaine 0.50% (1 mg/kg) and ropivacaine 0.75% (1.4 mg/kg). The onset of sensory and motor block, their duration, onset of surgical block, anaesthetic plane and possible adverse events were recorded. RESULTS: The duration of sensory block was longer in group of patients treated with levobupivacaine than in two other groups. Surgical onset was similar for levobupivacaine and ropivacaine, but it was delayed for racemic bupivacaine. In group of patients who received racemic bupivacaine, two episodes of reduction in heart rate without significant hypotension have been observed. The anaesthetic plan was satisfactory in the all three groups of patients. CONCLUSIONS: In our experience levobupivacaine has been demonstrated to be a good substitute for racemic bupivacaine. Compared to ropivacaine, levobupivacaine induces a longer duration of postsurgery analgesia and, in our opinion, this datum seems to be the most significant.     

Réponse ventilatoire au dioxyde de carbone après bloc axillaire avec fentanyl et lidocaïne

Respiratory parameters, ventilatory response to carbon dioxide and quality of anaesthesia were studied in patients undergoing upper limb surgery under axillary blockade. Thirteen patients were randomly assigned to two groups, group A (n = 6), who were given 35 ml of 1.5 % lidocaine with 1 in 200 000 of adrenaline, and group B (n = 7), who received 1 μg · kg⁻¹ of fentanyl with the same dose of lidocaine. Quality of the sympathetic, sensory and motor blocks were tested at 15 min (T1) and 45 min (T2) after the injection (T0). The other parameters measured at these three times, both with the patient in a half-sitting position breathing room air, and after a rebreathing test with CO₂ through Read's circuit, were respiratory rate (FR), tidal volume (Vt), minute ventilation (V̇e), and Petco₂. Fentanyl provided a better sensory and motor blockade at T1, without any difference in sympathetic blockade. The quality of the blocks was similar in both groups at T2. There were no significant differences in the respiratory parameters between the two groups. Moreover, there was no untoward effect due to fentanyl (nausea, pruritus). It is concluded that 1 μg · kg⁻¹ fentanyl added to a local anaesthetic solution may be useful, at least during the first hour of an axillary block, without any respiratory side-effects.     

A comparison of the vertical infraclavicular and axillary approaches for brachial plexus anaesthesia

BACKGROUND: This prospective, randomized study compared the efficacy of the vertical infraclavicular and axillary approaches using a single injection blockade of the brachial plexus. The primary endpoint was complete blockade in dermatomes C5-Th1, while secondary endpoints included onset time, motor block, block performance time, surgical success rate, patient satisfaction, and side-effects/complications. METHODS: Sixty patients, American Society of Anesthesiologists physical status I or II, scheduled for surgery of the forearm or hand received either a vertical infraclavicular (n = 30) or an axillary block (n = 30). A single injection of 0.5 ml/kg ropivacaine 7.5 mg/ml was made after electrolocalization of nerve fibres corresponding to the median nerve at maximum 0.5 mA (2 Hz, 0.1 ms). Onset and distribution of analgesia and motor block were assessed at 5, 10, 15, 20, 30 and 60 min after the local anaesthetic injection. A complete block was defined as analgesia in all dermatomes (C5-Th1) at 60 min post-injection. RESULTS: The vertical infraclavicular approach provided complete blockade in 29 patients (97%) and the axillary approach in 23 patients (77%). Analgesia in C5-C6 dermatomes and corresponding motor block occurred significantly more frequently in the vertical infraclavicular approach, which also had the shortest onset time. Block procedure was quicker in the axillary approach. Side-effects were similar in both groups, and there were no permanent sequelae. Patient satisfaction was equally high in both groups. CONCLUSION: The vertical infraclavicular approach provides a more complete block than the axillary approach when using a single injection technique and equal volumes/doses of local anaesthetic.