naloxone and Scoliosis

Wake-up tests may be necessary during scoliosis surgery to ensure that spinal function remains intact.. Intra- and postoperative wake-up tests were performed together with somatosensory cortical evoked potentials (SCEPs) monitoring in 40 patients randomized to either midazolam (M) or propofol (P) infusions for scoliosis surgery. Other anaesthetic medication was similar in both groups. At the surgeon's request, N2O was turned off and midazolam or propofol infusions were discontinued. In the M group, flumazenil was given in refracted doses. Patients were asked to move hands and feet. The test was repeated immediately after the end of surgery.. The median intraoperative wake-up times were 2.9 min in the M group and 16.0 min in the P group. The respective postoperative wake-up times were 1.8 and 13.9 min. The quality of both intra- and postoperative arousals was significantly better in the M group. Twelve patients in the P group could not be awakened intraoperatively within 15 min and were given naloxone. One of these patients woke up violently and dislodged the endotracheal tube. Another patient in the P group had explicit recall of the test, but no pain. Five patients in the M group became resedated in the recovery room. Cost of anaesthetic drugs was similar in both groups. Satisfactory intraoperative SCEPs were recorded from 17 patients in each group. There were no neurological sequelae.. Wake-up tests can be conducted faster and better with midazolam-flumazenil sequence compared with propofol.

Topics: Adolescent; Adult; Anesthesia Recovery Period; Anesthesia, Intravenous; Anesthetics, Intravenous; Antidotes; Arousal; Child; Drug Costs; Evoked Potentials, Somatosensory; Female; Flumazenil; Humans; Intraoperative Care; Intubation, Intratracheal; Male; Memory; Midazolam; Monitoring, Intraoperative; Naloxone; Narcotic Antagonists; Pain; Postoperative Care; Propofol; Prospective Studies; Psychomotor Performance; Scoliosis; Spinal Cord; Wakefulness

Topics: Adolescent; Anesthesia; Female; Humans; Naloxone; Narcotic Antagonists; Postoperative Complications; Pulmonary Edema; Scoliosis; Spinal Fusion

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. The functional abnormalities are the result of preexistent pulmonary disease or other disease processes that impair respiratory function, the anticipated effects of major surgery (e.g., pulmonary resection), and the complications of anesthesia and surgery. 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.

Topics: Anesthetics; Anti-Anxiety Agents; Autonomic Nervous System; Barbiturates; Benzodiazepines; Carbon Dioxide; Fentanyl; Halothane; Humans; Hyperthyroidism; Hypoxia; Lung Diseases, Obstructive; Meperidine; Methoxyflurane; Morphine; Naloxone; Neuromuscular Blocking Agents; Neuromuscular Diseases; Obesity; Pulmonary Edema; Pulmonary Fibrosis; Respiration; Scoliosis