Anesthesia and analgesia
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Fifty-four patients developed severe intercostal neuralgia a few weeks after sternotomy. Immediate relief afforded by parasternal nerve blocks confirmed that the pain derived from scar-entrapped neuromas of the anterior rami of the first 4-6 intercostal nerves in the upper (and mainly left) interchondral spaces after insertion of the sternal wires. Permanent relief (i.e., over 6 months) followed repeated bupivacaine blocks in 57.4% of the patients, phenol blocks in another 22.2%, and alcohol blocks in a remaining 9%. Treatment was successful in 87% of the patients.
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Anesthesia and analgesia · Jul 1989
Comparative StudyDiffering effect of agonist and antagonist muscle relaxants on cat jaw muscles.
Mouth closure and an increased resistance to mouth opening follow succinylcholine administration in humans. To elucidate the effects of succinylcholine on masticatory muscle function, mouth opening in the cat, produced by a constant test force, was measured during steady state halothane anesthesia. After baseline measurements, either succinylcholine (0.3 mg.kg-1 of body weight) or vecuronium (0.1 mg.kg-1 of body weight) was infused intravenously, and mouth opening measurements were repeated for up to 30 min. ⋯ Vecuronium administration was associated with a decreased resistance to mouth opening without a closing action. The initial jaw closure and the subsequently increased resistance to mouth opening after succinylcholine administration during halothane anesthesia in the cat are comparable with mouth opening changes after succinylcholine administration during inhalation anesthesia in humans. The cat may serve as an animal model for study of the mechanisms involved in responses of jaw muscles to succinylcholine with use of techniques inappropriate in humans.
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Anesthesia and analgesia · Jul 1989
Effects of enflurane on contractile response of canine trachealis muscle.
The effect of enflurane anesthesia on bronchomotor tone was studied in 15 dogs, using isolated tracheal segments in situ. In six animals, the changes of tracheal tension in response to changing enflurane concentration were continuously measured while keeping tidal volume, respiratory frequency, and end-tidal PCO2 constant. In nine other dogs, the contractile response to a brief period of apnea was assessed in three planes of anesthesia, namely 0% (baseline anesthesia with pentobarbital), 1%, and 2% of inspired enflurane concentration. ⋯ Furthermore, the magnitude of contraction elicited by electrical stimulation of the recurrent laryngeal nerve (RLN) was determined at each depth of anesthesia in six animals. Increasing enflurane concentrations invariably decreased resting tracheal tension as well as the magnitude of contraction in response to apnea and RLN stimulation in a dose-dependent manner. These data suggest that enflurane not only decreases unstimulated canine bronchomotor tone but also inhibits contraction produced by various stimuli used in the present experiments.