Effect of a target-controlled infusion of remifentanil in combination with desflurane during the "maintenance" phase of general anesthesia.

BACKGROUND: The goal of this study was to determine the optimal target-controlled concentration of remifentanil combined with desflurane, by using a more widely and decreasing end-tidal concentration of desflurane. METHODS: Ninety ASA I patients, who underwent general anesthesia for elective orthopedic or extremity surgeries, were registered and randomly allocated to receive either a target-controlled concentration of 1 ng/ml (group R1), 2 ng/ml (group R2) remifentanil, or desflurane only without remifentanil infusion (group D). Mean arterial pressure (MAP) and heart rate (HR) were recorded at 5-min intervals from after a 10-15 min period of surgical incision to before a 10-min period prior to the end of an operation. End-tidal concentration of desflurane was increased or decreased in proportion to the changes in MAP and HR. If the value of bispectral index (BIS) was from 60-62 for more than 2 min or systolic blood pressure would fall below 90 mmHg, the patient was excluded from the study to prevent a risk of "explicit awareness" and shock. RESULTS: The end-tidal desflurane concentration was lower in the group receiving 1 ng/ml (5.2 ± 0.5 vol%; P < 0.001) and 2 ng/ml remifenanil (4.4 ± 0.5 vol%; P < 0.001) compared to patients in group D (7.9 ± 0.5 vol%). CONCLUSIONS: We recommend the use of 2 ng/ml or less remifentanil combined with desflurane for decreasing concentrations of desflurane without significant side effects, during the "maintenance" phase, and not during the induction phase of general anesthesia.

Respiratory failure due to myotonic dystrophy combined with peripartum cardiomyopathy: A case report.

Myotonic dystrophy is an autosomal-dominant inherited neuromuscular disorder that's characterized by slowly progressive muscular dystrophy, muscle weakness and myotonia. The clinical features may vary from just cataracts to involvement of multiple organ systems such as various muscles, the heart, lung and intestine. Its most common complication is postoperative respiratory failure. We encountered a patient who developed sudden unexpected peripartum cardiomyopathy (PPCM) and respiratory failure due to presumed myotonic dystrophy after cesarean section. We report here on our clinical experience with this malady and we include a brief review of the medical literature on myotonic dystrophy.