Articles: anesthetics.
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The clinical effectiveness and safety of compounded mixtures of lidocaine + bupivacaine and chloroprocaine + bupivacaine for either epidural or brachial-plexus block was studied in 48 adult patients. Of the several alternatives, chloroprocaine + bupivacaine with epinephrine was found the best choice for patients with typical plasma cholinesterase.
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This study assesses the effects of agents commonly used in anaesthesia on enflurane-induced seizure threshold and on established seizure activity, during steady state enflurane anaesthesia. EEG seizure activity was monitored in cats from chronic cortical and subcortical recording sites. Diazepam, thiopentone, methohexitone and ketamine all enhanced established EEG seizure challenge. ⋯ The effects of these intravenous agents on established enflurane seizure patterns exceeded in duration the expected EEG effect of the agent when used alone. The limited number of experiments, however, precluded statistical verification of our findings. The similarities between centrencephalic minor motor seizures and enflurane seizure pattern in terms of EEG and convulsive expression, including drug response, are noted.
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Int Anesthesiol Clin · Jan 1977
The effects of anesthetic drugs and disease on the chemical regulation of ventilation.
The anesthesiologist uses a wide spectrum of drugs, including inhalational general anesthetics, barbiturates, benzodiazepines, narcotics analgesics and their antagonists, and neuromuscular blocking drugs. All of these drugs in sufficient dose impair the ventilatory response to chemical stimuli, and may cause inadequate gas exchange. The effect of depression of ventilatory control depends on the magnitude of depression and the coexistence of functional abnormalities in the respiratory system. ⋯ From a functional viewpoint, the mechanisms of the effects of these disease processes on ventilatory control are: (1) interference with the neurophysiological control of automatic ventilation; (2) impairment of peripheral or central chemoreceptor function; (3) impairment of respiratory muscle function; (4) increase in the mechanical load to breathing as a result of increased resistance or decreased compliance of the respiratory system; and (5) increase in the ventilatory requirements as a result of ventilation/blood flow maldistribution, metabolic acidosis, or increased metabolic rate. As a result of current trends in the use of multiple drugs and controlled ventilation during anesthesia, the patient is at greatest risk during the early postoperative period in the recovery room. In addition to the functional abnormalities described above, the probability of impaired gas exchange and respiratory failure is increased as a result of impaired metabolism and elimination of drugs as a result of hepatic and renal insufficiency, and acute changes in acidbase status, which alter the ionization and distribution of drugs.