Articles: nerve-block.
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Anesthesia and analgesia · Jun 1996
Comparative Study Clinical Trial Controlled Clinical TrialThe effect of stabilization on the onset of neuromuscular block when assessed using accelerometry.
Accelerometry is increasingly being used for neuromuscular monitoring. We sought to determine whether this system is sensitive to the period of stabilization of muscle twitch prior to the administration of neuromuscular relaxant. We recruited 20 patients. ⋯ The data collected was subjected to a paired t-test with P < 0.05 taken as significant. The mean onset times for patients who received vecuronium was 148.5s for the arms stabilized for 3 min and 151.5s for the arms stabilized for 20 min, and in those who received atracurium it was 138.0s and 130.5s, respectively. We conclude that there is no significant difference in the onset of neuromuscular block with either vecuronium or atracurium after stabilization periods of 3 or 20 min when assessed by accelerometry.
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Randomized Controlled Trial Clinical Trial
[Conduction block in man is stimulation frequency dependent].
The action of local anaesthetics on isolated nerves is enhanced by high stimulation frequencies. The aim of our study was to investigate whether high-frequency stimulation enhances regional anaesthesia in man. METHODS. ⋯ The spread of sensory block at the end of the experiments was also enhanced by stimulation with high frequencies, whereas the onset of vasomotor block (rise in skin temperature) remained unaltered. CONCLUSION. Non-oxious electrical stimulation with high frequencies significantly accelerates the onset of anaesthesia and extends the spread of sensory block.
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Clinically, differential block is manifested by the loss of small fiber mediated sensation (e.g., temperature) two or more dermatomes beyond the sensory limit for large fiber mediated sensations. These observations support the belief that sensitivity to local anesthetics is inversely proportional to axon diameter. This study reports the first measurements of differential sensitivity to lidocaine in individual myelinated and unmyelinated mammalian dorsal root axons. ⋯ Although no difference in sensitivity to the conduction blocking effects of lidocaine could be demonstrated among dorsal root axons, myelinated axons were more sensitive to the conduction velocity slowing effects of lidocaine. This differential effect cannot explain clinical observations of differential nerve block. Differential sensory block with lidocaine may depend on factors (e.g., physiologic function) related only indirectly to individual axon conduction velocity (diameter).
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Anaesth Intensive Care · Jun 1996
Randomized Controlled Trial Comparative Study Clinical TrialComparison of subcutaneous ring block of the penis with caudal epidural block for post-circumcision analgesia in children.
A randomized, prospective, blind trial was conducted comparing caudal epidural blockade (caudal block) with subcutaneous ring block of the penis (penile ring block) in fifty healthy boys between two and twelve years of age undergoing elective circumcision. Subjects receiving caudal block had a longer duration of analgesia (P = 0.003), and took longer to first micturition (P = 0.04) but there was no difference in time taken to awaken from anaesthesia or spontaneously walk unaided. ⋯ It is concluded that both techniques are effective. Caudal block is more reliable and produces a longer duration of analgesia but penile ring block is inherently safer and has a lower incidence of adverse effects.