Influence of videolaryngoscopy using McGrath Mac on the need for a helper to perform intubation during general anaesthesia: a multicentre randomised video-no-video trial.

OBJECTIVE: We hypothesised that videolaryngoscopy modifies practice of tracheal intubation. DESIGN: Randomised single-blinded study (video and no-video groups). SETTING: Three institutions: one academic, one non-profit and one profit. PARTICIPANTS: Patients >18 years, requiring orotracheal intubation, without predicted difficult intubation. Non-inclusion criterion was patients requiring a rapid-sequence intubation. 300 patients were included, 271 randomised, 256 analysed: 123 in the no-video and 133 in the video groups. INTERVENTION: Tracheal intubation using a McGrath Mac videolaryngoscope, the sequence being video recorded. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the proportion of intubations where assistance is necessary on request of the operator. Secondary outcomes included intraoperative variables (intubation difficulty scale and its components, percentage of glottic opening score, oesophageal Intubation, duration of intubation, removal of the screen cover in the no-video group, global evaluation of the ease of intubation, bispectral index, heart rate and blood pressure), intraoperative and postoperative complications (hoarseness or sore throat) and cooperation of the anaesthesiology team. RESULTS: Requirement for assistance was not decreased in the Video group: 36.1% (95% CI 27.9 to 44.9) vs 45.5% (95% CI 36.5 to 54.7) in the no-video group, p=0.74; OR: 0.7 (95% CI 0.4 to 1.1) and absolute risk: 0.10 (95% CI -0.03 to 0.22). Intubation difficulty scale was similar in both groups (p=0.05). Percentage of glottic opening score was better in the Video group (median of 100 (95% CI (100 to 100) and 80 (95%CI (80 to 90) in the no-video group; p<0.001) as Cormack and Lehane grade (p=0001). Ease of intubation was considered better in the video group (p<0.001). Other secondary outcomes were similar between groups. Screen cover was removed in 7.3% (95% CI (2.7 to 11.9)) of the cases in the video group. No serious adverse event occurred. Communication and behaviour within the anaesthesia team were appropriate in all cases. CONCLUSION: In patients without predicted difficult intubation, videolaryngoscopy did not decrease the requirement for assistance to perform intubation. TRIAL REGISTRATION NUMBER: NCT02926144; Results.

HYPNOTIC GLOVE ANESTHESIA INDUCES SKIN TEMPERATURE CHANGES IN ADULT VOLUNTEERS: A Prospective Controlled Pilot Study.

This study assessed whether a focal glove hypnotic hand anesthesia induced thermal changes within the area of hypnotic protection. Skin temperature of hands, wrists, and forearms was continuously recorded bilaterally using infrared thermography in 30 volunteers. Thermal recordings were obtained prior to, after glove building, and after its withdrawal, with the contralateral upper limb serving as control side. Analgesic glove induced a statistically significant difference in temperature variation within the hand, wrist, and distal forearm on the glove side, compared with proximal forearm and control side. Hypnotic glove analgesia provides significant changes in skin temperature within protected areas. Further research is required to determine the mechanisms of these objective changes induced by hypnosis.

Impact of a Hypnotically-Based Intervention on Pain and Fear in Women Undergoing Labor.

The purpose of this study was to evaluate the effects of a hypnotically-based intervention for pain and fear in women undergoing labor who are about to receive an epidural catheter. A group of 155 women received interventions that included either (a) patient rocking, gentle touching, and hypnotic communication or (b) patient rocking, gentle touching, and standard communication. The authors found that the hypnotic communication intervention was more effective than the standard communication intervention for reducing both pain intensity and fear. The results support the use of hypnotic communication just before and during epidural placement for women who are in labor and also indicate that additional research to evaluate the benefits and mechanism of this treatment is warranted.

A randomized, observer-blinded determination of the median effective volume of local anesthetic required to anesthetize the sciatic nerve in the popliteal fossa for stimulating and nonstimulating perineural catheters.

BACKGROUND AND OBJECTIVES: Stimulating perineural catheters are developed to overcome technical problems of nonstimulating catheters, but their efficacy remains controversial. However, no volume-response study has compared success rates between stimulating and nonstimulating catheters. This study of stimulating versus nonstimulating catheters compares the minimal effective volume required to successfully block the sciatic nerve in 50% of patients scheduled for unilateral hallux valgus repair. METHODS: Patients underwent unilateral sciatic nerve block in the popliteal fossa with mepivacaine 1.5%, using either a stimulating (STIM group) or a nonstimulating (NONSTIM group) popliteal catheter. The volume of mepivacaine started at 20 mL and was increased or decreased by increments of 2 mL in subsequent patients, depending on the efficacy of the block in the previous patient, using the technique of up-down sequential allocation described by Dixon (Neurosci Biobehav Rev. 1991;15:47-50). Minimum effective volumes of local anesthetic were calculated using the formula of Dixon. Efficacy of block was defined by a complete sensory-motor block in the cutaneous distributions of the sciatic nerve associated with a pain-free surgery. RESULTS: Twenty-four patients were included in each group. Median effective volume blocking the sciatic nerve was significantly lower (P < 0.05) in the STIM group (2.7 mL; 95% confidence interval, 0.5-4.9 mL) compared with the NONSTIM group (16.6 mL; 95% confidence interval, 15.2-18.0 mL). CONCLUSION: Stimulating popliteal catheters dramatically decrease the volume required to block the sciatic nerve in 50% of patients, compared with nonstimulating catheters.

Ultrasound- or nerve stimulation-guided wrist blocks for carpal tunnel release: a randomized prospective comparative study.

BACKGROUND AND OBJECTIVES: We hypothesized that ultrasound-guided wrist blocks may be faster to perform, and may increase success rate, compared with nerve stimulation-guided wrist blocks. METHODS: Sixty patients undergoing ambulatory endoscopic carpal tunnel release were randomly allocated to receive median and ulnar nerve blocks using either sensory-motor nerve stimulation (n = 30) or ultrasound guidance (n = 30). Four mL of mepivacaine 1.5% was injected around each nerve. Performance time and onset time of complete sensory block were assessed. RESULTS: Median time to perform both median (ultrasound, 55 [48-60] vs. nerve stimulation, 100 [65-150] seconds, P = .002) and ulnar (ultrasound, 57 [50-70] vs. nerve stimulation, 80 [60-105] seconds, P = .02) nerve blocks were significantly shorter in the ultrasound group. Onset time of complete sensory block in the median (ultrasound, 370 [278-459] vs. nerve stimulation, 254 [230-300] seconds, P = .02) and ulnar (ultrasound, 367 [296-420] vs. nerve stimulation, 241 [210-300] seconds, P = .01) nerve areas were shorter in the nerve stimulation group. The success rate was 93% in both groups. CONCLUSIONS: This randomized prospective study demonstrates that ultrasound-guided wrist nerve blocks are as efficient as those performed with nerve stimulation.

Time sequence of sensory changes after upper extremity block: swelling sensation is an early and accurate predictor of success.

BACKGROUND: Sensory assessment to estimate spread and effectiveness of a peripheral nerve block is difficult because no clinical test is specific for small sensory fibers. Occurrence of a swelling illusion (SI) during a peripheral nerve block corresponds to the impairment of small sensory fibers. The authors investigated the usefulness of SI in predicting successful peripheral nerve block by assessing the temporospatial correlation between progression of sensory impairment in cutaneous distributions anesthetized and localization of SI during peripheral nerve block installation. METHODS: Interscalene, infracoracoid, or sciatic nerve blocks were performed using a nerve stimulator and 1.5% mepivacaine in 53 patients, with a total of 201 nerves to be anesthetized. Pinprick, cold, warm, touch, and proprioception were assessed every 3 min, while patients were asked to describe their perception of size and shape of their anesthetized limb and localization of these illusions. Data are presented as mean +/- SD and percentage (95% confidence interval). RESULTS: Failure occurred in 12 cutaneous distributions out of a total of 201 theoretically blocked nerves. SI appeared earlier than warmth impairment (4.3 +/- 2.7 vs. 6.2 +/- 2.0 min; P < 0.05), always corresponding to successfully anesthetized cutaneous distributions, with the exception of 1 patient, who developed SI in 2 cutaneous distributions while sensory testing indicated failure in 1 distribution. SI successfully predicted the blockade of a cutaneous distribution with a sensitivity of 1.00 (0.98-1.00), a specificity of 0.92 (0.65-0.99), and an accuracy of 0.99 (0.97-1.00). CONCLUSIONS: Swelling illusion may provide an early assessment of the success of a peripheral nerve block in unsedated patients.

Influence of sensory and proprioceptive impairment on the development of phantom limb syndrome during regional anesthesia.

BACKGROUND: The relation between impairment of sensorimotor function and occurrence of phantom limb syndrome (PLS) during regional anesthesia has not been described. This study assessed the temporal relation between PLS and the progression of sensorimotor impairment during placement of a brachial plexus nerve block. METHODS: Fifty-two patients had their arm randomly placed either alongside their body (group A) or in 90 degrees abduction (group B) immediately after brachial plexus nerve block placement. Responses to pin prick, cold, heat, touch, proprioception, and voluntary movement were assessed every 5 min for 60 min. Meanwhile, patients described their perceptions of the size, shape, and position of their anesthetized limb. RESULTS: Phantom limb syndrome occurred 19 +/- 9 min after nerve block placement. Proprioception was impaired and abolished after 22 +/- 9 and 43 +/- 17 min, respectively (P < 0.05 vs. PLS onset). When PLS occurred, responses to pin prick, cold, heat, and proprioception were abolished in 96, 94, 87, and 4% of patients, respectively. Patients were more likely to feel their anesthetized limb in adduction and in abduction in groups A and B (P < 0.05 vs. group A), respectively. After PLS had become motionless, two stereotyped positions were identified: arm adduction, elbow flexion, hand over the abdomen (68% of group A patients) and arm abduction, elbow flexion, hand held close to the homolateral ear (48% of group B patients). CONCLUSIONS: This study provides a better understanding of the determinants of PLS by showing that the final position of PLS is related both to the abolition of proprioception and the initial position of the anesthetized limb.

An unusual case of painful phantom-limb sensations during regional anesthesia.

OBJECTIVE: The objective of this article is to describe a late-onset phantom-limb pain during a continuous analgesic popliteal nerve block after foot surgery and its alleviation and recurrence when stopping and resuming the local anesthetic infusion. CASE REPORT: A 29-year-old woman undergoing a left hallux valgus repair received a continuous popliteal sciatic nerve block for postoperative analgesia. Postoperatively, 6 hours after the commencement of a ropivacaine 0.2% infusion, she reported feelings of tingling, clenching pain, and missing-limb sensation below the ankle. The surgical site remained painless. Sensation elicited by touch and propioception were normally perceived. Only sensations for pinprick and heat were impaired. The ropivacaine infusion was stopped, followed 2.5 hours later by the complete regression of any abnormal sensation. Meanwhile, pain at the surgical site was scored at 50 mm on a 100-mm visual analogic scale. As the infusion of ropivacaine was resumed, the abnormal sensations reappeared. The catheter was removed, and abnormal sensations again disappeared. The patient was discharged from hospital without further complications. CONCLUSIONS: This observation suggests that phantom-limb pain can be of late-onset and might occur during a continuous infusion of low-concentration local anesthetic responsible only for an analgesic block, as shown by the fact that only thermal and pinprick sensations, known to depend on Adelta-fibers and C-fibers, were altered. Therefore, this case contradicts the usual belief that a profound block is necessary to elicit phantom-limb pain.

Plasticity in action of intrathecal clonidine to mechanical but not thermal nociception after peripheral nerve injury.

BACKGROUND: Intrathecal clonidine reduces tactile allodynia in animal models of neuropathic pain, and this effect is blocked by atropine. However, the role of tonic spinal cholinergic activity and its interaction with alpha2-adrenergic systems in normal and neuropathic conditions and to different sensory methods has not been systematically examined. The authors examined cholinergic receptor involvement in thermal and mechanical sensitivity in normal and neuropathic animals and its interaction with intrathecal clonidine. METHODS: Normal rats and rats that received L5/L6 spinal nerve ligation were tested with acute radiant heat, paw pressure, and punctate mechanical stimulation before and after the intrathecal administration of saline, the muscarinic receptor antagonist, atropine, or a toxin to destroy cholinergic neurons, and then after intrathecal clonidine. RESULTS: Atropine, the cholinergic neuronal toxin, and saline did not alter baseline withdrawal thresholds. In nerve-injured rats, neither saline nor atropine altered antinociception from clonidine to a thermal stimulus, but atropine reduced the effect of clonidine to von Frey filament withdrawal threshold (34 +/- 5.6 vs. 14 +/- 5.8 g [mean +/- SEM], saline vs. atropine; P < 0.05) and to withdrawal threshold to paw pressure after clonidine (174 +/- 18 g vs. 137 +/- 16 g, saline vs. atropine; P < 0.05). CONCLUSIONS: These data suggest that after nerve injury, mechanical but not thermal antinociception from intrathecal clonidine relies on a muscarinic interaction, because only mechanical antinociception was antagonized by atropine. These results do not favor a regulation of nociceptive transmission by a tonic release of acetylcholine in nerve-injured rats.

Brachial plexus nerve block exhibits prolonged duration in the elderly.

BACKGROUND: Upper limb trauma occurs frequently in elderly patients for whom peripheral nerve blocks are often preferred for anesthesia. The characteristics of such regional blocks have, however, never been described in an elderly population. Therefore, the authors assessed prospectively the onset and duration of upper extremity peripheral nerve block (the mid-humeral block) in elderly and young patients undergoing emergency upper extremity surgery. METHODS: Consecutive patients aged > 70 yr or < 70 yr received a mid-humeral block with a small volume of ropivacaine, 0.75%. Five milliliters was injected onto each of the musculocutaneous, radial, ulnar, and median nerves. Time to complete sensory and motor block and durations of complete sensory and motor block were assessed. Results are shown as median and its 95% confidence interval. RESULTS: Median ages were 77 yr (95% CI, 72-81 yr) and 39 yr (95% CI, 27-46 yr) in the two groups. Both groups had similar times to complete sensory blockade. The elderly group had longer durations of complete sensory (390 min [range, 280-435 min] vs.150 min [range, 105-160 min]; P< 0.05) and motor (357 min [range, 270-475 min] vs. 150 min [range, 90-210 min]; P< 0.05) blockade. Duration of complete sensory block was significantly correlated with age (rho = 0.56; P< 0.05). CONCLUSIONS: Age is a major determinant of duration of complete motor and sensory blockade with peripheral nerve block, perhaps reflecting increased sensitivity to conduction failure from local anesthetic agents in peripheral nerves in the elderly population.

Detection of brain death onset using the bispectral index in severely comatose patients.

OBJECTIVES: To evaluate the accuracy of bispectral index (BIS) monitoring for the diagnosis of brain death in severely comatose patients. DESIGN: A prospective study in an intensive care unit of a university hospital. POPULATION: Fifty-six severely comatose patients (Glasgow Coma Score < or = 5) admitted to the ICU mainly because of intracerebral hemorrhage, head injury, or postanoxic coma. METHODS: BIS was recorded continuously during the hospitalization in the ICU. Where necessary, clinical brain death was confirmed by EEG or cerebral angiography. MEASUREMENTS AND RESULTS: Twelve patients were already clinically brain dead at the time of admission, and their individual BIS values were 0. In each of these 12 patients brain death was thereafter confirmed by EEG or cerebral angiography. Forty-four patients were not clinically brain-dead at the time of admission, and their individual BIS values were between 20 and 79. Twenty-seven of these patients became brain-dead, and their individual BIS values dropped to 0 in a few hours to a few days. In these 27 patients EEG or cerebral angiography was performed after the BIS value decreased to 0 and confirmed brain death in all cases. Seventeen patients who did not become brain dead during their hospitalization in the ICU had persistent electrocerebral activity on EEG, and their average BIS values remained above 35. CONCLUSION: BIS can be used in severely comatose patients as an assessment of brain death onset, enabling appropriate scheduling of either EEG or cerebral angiography to confirm brain death.

The clinical efficacy and pharmacokinetics of intraperitoneal ropivacaine for laparoscopic cholecystectomy.

UNLABELLED: Postoperative pain after laparoscopic surgery is less than after laparotomy, and patients may benefit from an intraperitoneal injection of local anesthetic. Thirty-seven ASA physical status I or II patients received in double-blinded fashion 20 mL of 0.9% saline solution (placebo), ropivacaine 0.25% (Rop 0.25%), or ropivacaine 0.75% (Rop 0.75%) immediately after trocar placement and at the end of surgery. We measured pain and morphine consumption until 20 h after surgery. Plasma ropivacaine concentrations were measured. The three groups were comparable for shoulder pain, parietal pain, and incidence of side effects. Visceral pain at rest, during cough, and on movement and total consumption of morphine were significantly smaller in Groups Rop 0.25% and Rop 0.75% when compared with Placebo. Although no adverse effect occurred in any patient, the largest dose led to large plasma concentrations of ropivacaine (2.93 +/- 2.46 microg/mL and 3.76 +/- 3.01 microg/mL after the first and second injection, respectively). We conclude that intraperitoneal administration of ropivacaine before and after surgery significantly decreases postoperative pain. Because the smaller dosage (2 x 50 mg) provided similar analgesia and was associated with significantly smaller plasma concentrations than the larger dosage (2 x 150 mg), this smaller dosage seems more appropriate. IMPLICATIONS: Intraperitoneal ropivacaine 100 mg injected during laparoscopic cholecystectomy significantly decreased postoperative pain when compared with injection of intraperitoneal placebo. At this dose, plasma concentrations remained in the nontoxic range,