Assessment of the technique of the anesthetic block of the Brachial Plexus by Supraclavicular approach in Sapajus libidinosus (SPIX, 1823).

BACKGROUND: The aim of study was to evaluate the efficacy of the supraclavicular brachial plexus block technique in Sapajus libidinosus. METHODS: Were used eight animals, which were sedated, anesthetized, kept under hypnosis, and submitted to plexus block using a neurolocalizer. The physiological parameters, the nociception and response threshold (mA), were evaluated before and after the block. The response to electrical stimulation and cutaneous sensitivity were evaluated. The groups were compared by the Tukey or Friedman test at 5%. RESULTS: The technique promoted blockage of the plexus, and movement of the thoracic limb in response to electrical stimulation decreased after 10 minutes. The applied milliampere increased after 5 minutes. The cutaneous sensitivity reflex decreased. The average time of return of spontaneous limb movement exceeded 50 minutes. CONCLUSIONS: The use of 5mg/kg of lidocaine 2% promoted loss of cutaneous sensitivity and limb muscle relaxation during the evaluation period.

An Expedited Care Pathway with Ambulatory Brachial Plexus Analgesia Is a Cost-effective Alternative to Standard Inpatient Care after Complex Arthroscopic Elbow Surgery: A Randomized, Single-blinded Study.

BACKGROUND: Common standard practice after complex arthroscopic elbow surgery includes hospital admission for 72 h. The authors hypothesized that an expedited care pathway, with 24 h of hospital admission and ambulatory brachial plexus analgesia and continuous passive motion at home, results in equivalent elbow range of motion (ROM) 2 weeks after surgery compared with standard 72-h hospital admission. METHODS: A randomized, single-blinded study was conducted after obtaining approval from the research ethics board. Forty patients were randomized in a 1:1 ratio using a computer-generated list of random numbers into an expedited care pathway group (24-h admission) and a control group (72-h admission). They were treated equally aside from the predetermined hospital length of stay. RESULTS: Patients in the control (n = 19) and expedited care pathway (n = 19) groups achieved similar elbow ROM 2 weeks (119 ± 18 degrees and 121 ± 15 degrees, P = 0.627) and 3 months (130 ± 18 vs. 130 ± 11 degrees, P = 0.897) postoperatively. The mean difference in elbow ROM at 2 weeks was 2.6 degrees (95% CI, -8.3 to 13.5). There were no differences in analgesic outcomes, physical function scores, and patient satisfaction up to 3 months postoperatively. Total hospital cost of care was 15% lower in the expedited care pathway group. CONCLUSION: The results suggest that an expedited care pathway with early hospital discharge followed by ambulatory brachial plexus analgesia and continuous passive motion at home is a cost-effective alternative to 72 h of hospital admission after complex arthroscopic elbow surgery.

Assessment of long-term vasoplegia induced by brachial plexus block: a favorable effect for hemodialysis angioaccess surgery?

PURPOSE: Loco-regional anesthesia, along with the neurosensitive inhibition causes arterial and venous vasodilatation, that could be of interest for vascular access surgery. We evaluated the long term vasoplegia persistence after brachial plexic block. METHODS: Five patients submitted to brachial plexus block for an orthopedic procedure have been observed. Both radial arteries, that of the blocked arm and the opposite as a control, were analyzed by ultrasound examination, at time 0 and 360 minutes after anesthesia induction. All patients were treated with the same anesthesiologic protocol: axillary approach, use of an electroneurostimulator, injection 10 ml of ropivacain 7.5% + 10 ml of mepivacain 2%. The parameters evaluated from the arterial ultrasound flowmetry were: peak systolic velocity (PSV), end diastolic velocity (EDV) and resistance index (RI). RESULTS: No modification of the arterial flow were observed in the control arm at 0 and 360'after block induction. The blocked arm instead showed a significant decrease of the resistive index, stable at 360 minutes. CONCLUSIONS: The vasoplegia accompaning plexic block lasted 6 hours after anesthesia induction. Whereas this longstanding haemodynamic effect is beneficial for early patency of vascular access for hemodialysis, needs to be ascertained by further investigations.

[Ultrasonographic assessment of hemidiaphragm paralysis secondary to interscalene block]. / Evaluación ultrasonográfica de la parálisis hemidiafragmática secundaria a bloqueo interescalénico.

BACKGROUND: In shoulder surgery, interscalene brachial plexus block has an incidence of 100% hemidiaphragm palsy due to phrenic nerve block. Controling the hemidiaphragm becomes a security ventilation parameter. OBJECTIVE: identify and evaluate with ultrasound hemidiaphragm paralysis after interscalene block. METHODS: This prospective study included 50 patients scheduled for shoulder surgery with interscalene block using neurostimulation. Diaphragmatic movement was evaluated by ultrasound prior to placement of block and the end of the surgical procedure to make the comparison between the two measurements. RESULTS: Comparing the duration of the respiratory cycle at the start and the end of the surgical procedure, both normal and forced ventilation, there is a statistically significant difference of p < 0.001, as with the depth of the hemidiaphragm was found p < 0.001. 90% of patients had no adverse events, 8% had Horner's syndrome and 2% periauricular hypoesthesia. Hemidiaphragm paralysis was found in all cases, with a volume of 30 mL local anesthetic. CONCLUSIONS: Ultrasound is a reliable tool that allows real time viewing of the respiratory cycle and measurements of the diaphragm dome it serves to identify diaphragmatic hemiparesis.

[Risk management in brachial plexus block].

Peripheral nerve block has many advantages in surgical anesthesia with or without general anesthesia; postoperative analgesia, faster postoperative rehabilitation, and chronic pain management. However, serious adverse complications after peripheral nerve block can happen. Therefore, anesthetists should obtain full informed consent for possible complications, and require scrupulous attention to this procedure. This review focuses on complications of brachial plexus block because it is the most popular peripheral nerve block.

Is ultrasound guidance mandatory when performing paediatric regional anaesthesia?

PURPOSE OF REVIEW: Since Kapral in 1994 first described the use of real-time ultrasound-guided regional anaesthesia, this novel technique has gained widespread recognition in adult practice and has been shown to be associated with clinically relevant advantages. The aim of this manuscript is to review the currently published paediatric data associated with the use of ultrasound-guided regional anaesthesia. RECENT FINDINGS: Compared with alternative techniques ultrasound guidance is associated with an increased success rate, reduced onset time, moderately prolonged duration, reduced need for local anaesthetics and lower costs, and may also be considered to reduce the risk for complications. SUMMARY: Based on current data the use of ultrasound guidance is strongly recommended when performing peripheral nerve blocks in infants and children. Concerning ultrasound assistance in relation to paediatric neuroaxial blocks there is currently not enough supporting evidence to issue a general recommendation regarding its routine use.

Assessment of brachial plexus blockade in chickens by an axillary approach.

OBJECTIVE: To assess the brachial plexus block in chickens by an axillary approach and using a peripheral nerve stimulator. STUDY DESIGN: Prospective, randomized, double-blinded study. ANIMALS: Six, 84-week old, female chickens. METHODS: Midazolam (1 mg kg(-1)) and butorphanol (1 mg kg(-1)) were administered into the pectoralis muscle. Fifteen minutes later, the birds were positioned in lateral recumbency and following palpation of the anatomic landmarks, a catheter was inserted using an axillary approach to the brachial plexus. Lidocaine or bupivacaine (1 mL kg(-1)) was injected after plexus localization by the nerve stimulator. Sensory function was tested before and after blockade (carpus, radius/ulna, humerus and pectoralis muscle) in the blocked and unblocked wings. The latency to onset of motor and sensory block and the duration of sensory block were recorded. A Friedman nonparametric one-way repeated-measures ANOVA was used to compare scores from baseline values over time and to compare the differences between wings at each time point. RESULTS: A total of 18 blocks were performed with a success rate of 66.6% (12/18). The latency for motor block was 2.8 +/- 1.1 and 3.2 +/- 0.4 minutes for lidocaine and bupivacaine, respectively. The latencies for and durations of the sensory block were 6.0 +/- 2.5 and 64.0 +/- 18.0 and 7.8 +/- 5.8 and 91.6 +/- 61.7 minutes for lidocaine and bupivacaine, respectively. There was no statistical difference between these times for lidocaine or bupivacaine. Sensory function was not abolished in nonblocked wings. CONCLUSIONS AND CLINICAL RELEVANCE: The brachial plexus block was an easy technique to perform but had a high failure rate. It might be useful for providing anesthesia or postoperative analgesia of the wing in chickens and exotic avian species that have similar wing anatomy.

Somatosensory evoked potentials as an objective assessment of the sensory median nerve blockade after infraclavicular block.

PURPOSE: Median nerve somatosensory evoked responses (MnSSER) alterations were compared to clinical tests (cold and pinprick) variations, in 20 ASA I adult patients following infraclavicular block obtained with 40 mL ropivacaine 0.5% to assess first, the difference of time course of the respective electrophysiological and clinical signs, and second, the objectivity and the reproducibility of MnSSER changes. CLINICAL FEATURES: Four MnSSER derivations (Erb's point; cutaneous projection of peripheral end of brachial plexus; posterior neck at C6 level, frontal and controlateral parietal scalp) were monitored and recorded for retrospective analysis. Continuous data acquisition were started before ropivacaine injection (baseline) and maintained for 30 min thereafter. Every three minutes after ropivacaine injection, cold and pinprick tests were performed in the hand median nerve cutaneous supply zone and were assessed using a sensory visual score (varying from 0-10). Data were compared using analysis of variance. Although MnSSER values were stable during baseline period, after ropivacaine administration, severe progressive amplitude depressions of selected MnSSER were detected in every patient. While clinical cold and pinprick tests became positive (score > 8) only 15.8 +/- 1.2 min and 20.1 +/- 1.8 min respectively after ropivacaine administration, the mean time to observe the earliest MnSSER 20% amplitude decrease at Erb's point derivation was reduced to 5.6 +/- 1.1 min (P < 0.01). CONCLUSION: Selected MnSSER amplitude reduction indicates objectively the onset of median nerve anesthesia following infraclavicular brachial plexus block before the appearance of clinical signs.