Adequacy of General Anesthesia for Cesarean Section

Abstract

To assess the adequacy of the general anesthesia commonly employed for Cesarean section, we used isolated forearm technique to study 30 parturients (physical status ASA I/II, aged 17-35 yr) scheduled for nonemergent abdominal delivery. Anesthesia was induced with intravenous thiopental (3 mg/kg, 250 mg maximum) and succinylcholine (1.5 mg/kg), and then proceeded with a mixture of 50% N2O, 50% O2, and 0.5% halothane at a flow of 5 L/min and end-tidal CO2 at 40 mm Hg. Paralysis was maintained with a 0.1% succinylcholine infusion. When eyelash reflex disappeared, patients received taped instruction via headphones at 1-min intervals for 10 min. The tapes instructed patients to flex fingers if they were able to hear, to make a fist or squeeze the investigator's hand if they felt pain, to remember six target words, and to respond with specific physical signals during later interviews. Three sets of tapes assigned at random were used in the study. For signs of inadequate anesthesia, other variables such as eye centering, pupil size, sweating, and lacrimation were concomitantly monitored at the time of induction, laryngoscopy/intubation, and skin incision, and then at 1-min intervals for 10 min. Brain activity was also monitored by means of computerized aperiodic analysis of electroencephalogram Lifescan). Patients were interviewed in the postanesthesia recovery room and again 24 h later. At the time of skin incision, 96.7% of patients (29/30) signaled awareness by flexing fingers, 86.7% (26/30) exhibited lacrimation, and 80% (24/30) made a fist or squeezed the investigator's hand, indicating pain perception.(ABSTRACT TRUNCATED AT 250 WORDS)

Four cases of the ex utero intrapartum treatment (EXIT) procedure: anesthetic implications

“…8 Many textbooks still recommend the use of such a low dose of volatile agent (corresponding to 0.5-0.7 MAC inspired concentration) to decrease the risk for maternal awareness without inducing neonatal depression, uterine atony and increased maternal blood loss. 9;10 It is, however, important to realize that higher concentrations of volatile anesthetics could be necessary to eliminate the risk of awareness 11 and also to counteract the negative effects on uteroplacental perfusion from the maternal autonomic stress response. 12 During an EXIT procedure the ET concentration of the volatile agent is kept very high (approximately 2 MAC) in order to keep the uterus fully relaxed, provided that maternal hemodynamics and hence uteroplacental flow are not jeopardized.…”

General anesthesia for cesarean section in a Singapore maternity hospital: a retrospective survey

“…1 Mortality related to GA was the third commonest cause of maternal deaths in England and Wales in the early 1980s, with the majority of these due to failure of intubation or pulmonary aspiration of stomach contents. 2 The judicious administration of anesthetic agents, arising from concerns of excessive neonatal sedation, also led to an increased incidence of maternal awareness under GA. 3,4 Hence, there has been a growing trend towards the use of regional anesthetic techniques such that in certain obstetric centers, general anesthesia is used only for specific indications such as severe fetal distress requiring immediate surgical delivery. 5 While regional techniques may be associated with problems such as delays in the induction of anesthesia during emergency situations, postoperative immobility secondary to residual motor weakness, urinary retention and spinal headaches, 1 its relative safety has contributed to its increased popularity.…”

Tracheal Intubation through the I-gel for Emergency Cesarean Section in a Patient with Multidrug Hypersensitivity: A New Technique

“…However, it is not clear how quickly fentanyl crosses the placenta. Hence, keeping in mind the risk of fetal respiratory depression and low APGAR scores, its use was precluded in our patient before delivery of the baby [6]. Halaseh et al [7] reported that use of the Proseal laryngeal mask airway was effective in protecting against the risk of aspiration in 3000 elective Cesarean section patients with a minimum fasting period of 8 hr.…”