Alfentanil Given Immediately Before the Induction of Anesthesia for Elective Cesarean Delivery

Abstract

Opioids are routinely omitted at the induction of general anesthesia for cesarean delivery because of concerns about neonatal respiratory depression. The subsequent unmodified maternal stress response to tracheal intubation reduces placental perfusion. The short-acting opioid alfentanil may afford advantages at the induction, without subsequent neonatal depression. In this double-blinded study of elective cesarean deliveries, 40 patients were allocated randomly to receive either alfentanil 10 microg/kg (n = 18) or placebo (n = 22), 1 min before the induction of anesthesia with thiopental 4 mg/kg and succinylcholine 1.5 mg/kg. Anesthesia was maintained with 50% nitrous oxide, 0.5% isoflurane in oxygen, and atracurium. Neonates were assessed by using Apgar scores, Neurologic and Adaptive Capacity Scores, and umbilical cord blood gas and catecholamine analysis. After intubation, mothers receiving alfentanil had a smaller increase in mean arterial blood pressure, (11 +/- 15 vs 31 +/- 13 mm Hg, P < 0.001) and lower plasma norepinephrine concentrations, (336 +/- 152 vs 486 +/- 241 pg/mL, P < 0.05). Neonates in the alfentanil group had greater umbilical arterial oxygen tensions (27.8 +/- 7.0 vs 22.6 +/- 7.4 mm Hg), slightly reduced Apgar scores (both P < 0.05), but similar Neurologic and Adaptive Capacity Scores. One neonate in the alfentanil group required naloxone. The maternal stress response was attenuated in the alfentanil group but at the cost of early neonatal depression. However, all neonates should be monitored for possible immediate, but transient, respiratory depression.

Remifentanil for cesarean section under general anesthesia: effects on maternal stress hormone secretion and neonatal well-being: a randomized trial

“…Opioids are known to reduce the hypothalamic-adrenal response to surgery, 26 and to depress sympathetic activity in a dose-dependent manner. 27,28 Although norepinephrine secretion has been shown to be reduced by opioid administration, 29 in our study the increase in norepinephrine was not attenuated by remifentanil infusion, as previously described. 30 This supports the hypothesis that norepinephrine, released mainly from sympathetic nerve endings, is not significantly affected by systemic opioid administration.…”

Controle perioperatório de gestante obesa mórbida submetida a parto cesariano sob anestesia geral – relato de caso

“…17 Por isso, pode não ter a desvantagem da depressão respiratória neonatal associada ao fentanil e ao alfentanil. 18,19 A diminuição da capacidade residual funcional e o aumento na demanda de O 2 na gravidez resultam em mais rápido início da dessaturação de oxi-hemoglobina durante apneia em comparação com mulheres não gestantes. Na gestante obesa mórbida a instalação da dessaturação pode ser, ainda, mais rápida.…”

Undiagnosed phaeochromocytoma mimicking severe preeclampsia in a pregnant woman at term

“…Alfentanil has been shown to cause the least change in heart rate, while magnesium and alfentanil in combination produced better control of arterial pressure and heart rate than magnesium alone. [22][23][24] Magnesium also has powerful anti-arrhythmic effects in the presence of catecholamines and in arrhythmias resistant to proven anti-arrhythmic agents. 25 Inclusion of any of the above drugs at induction of anaesthesia, to suppress the maternal hypertensive response to intubation, would probably have provided a degree of cardiovascular stability in our patient.…”