[The effects of remifentanil used during cesarean section on oxidative stress markers in correlation with maternal hemodynamics and neonatal outcome: a randomized controlled trial]. / Os efeitos do remifentanil sobre os marcadores do estresse oxidativo durante a cesariana, em correlação com a hemodinâmica materna e o desfecho neonatal: um estudo randômico controlado.

BACKGROUND AND OBJECTIVE: Remifentanil is used to attenuate maternal hemodynamic response to intubation and surgical stress during Induction-Delivery period of cesarean section. The goal was to compare the effects of two remifentanil dosing regimens on oxidative stress level, in correlation with its hemodynamic and neonatal effects. METHODS: Fifty-one patients, 17 per group, enrolled for elective cesarean section were randomly divided by computer-generated codes into three parallel groups: (A) patients received a 1µg.kg-1 remifentanil bolus immediately before induction, followed by 0.15µg.kg-1.min-1 infusion, that was stopped after skin incision; (B) patients received a 1µg.kg-1 remifentanil bolus immediately before induction; (C) (control), patients did not receive remifentanil until delivery. Maternal venous blood samples were taken at basal time, at extraction and 30minutes after the end of operation for spectrophotometrical determination of malondialdehyde and advanced oxidation protein products concentration. The same was conducted for umbilical venous sample. RESULTS: Systolic blood pressure and heart rate remained significantly lower in group A compared to B and C during entire Induction-Delivery period (p<0.001, p=0.02 after intubation; p=0.006, p=0.03 after skin incision; p=0.029, p=0.04 after extraction; respectively). Malondialdehyde concentration was lower at time of extraction in maternal blood in group A compared to B and C (p=0.026). All neonatal Apgar scores were ≥ 8 and umbilical acid-base values within normal range. CONCLUSIONS: The remifentanil dosing regimen applied in group A significantly attenuated lipid peroxidation and maternal hemodynamic response during entire I-D period, without compromising neonatal outcome.

The effects of remifentanil used during cesarean section on oxidative stress markers in correlation with maternal hemodynamics and neonatal outcome: a randomized controlled trial / Os efeitos do remifentanil sobre os marcadores do estresse oxidativo durante a cesariana, em correlação com a hemodinâmica materna e o desfecho neonatal: um estudo randômico controlado

Abstract Background and objective: Remifentanil is used to attenuate maternal hemodynamic response to intubation and surgical stress during Induction-Delivery period of cesarean section. The goal was to compare the effects of two remifentanil dosing regimens on oxidative stress level, in correlation with its hemodynamic and neonatal effects. Methods: Fifty-one patients, 17 per group, enrolled for elective cesarean section were randomly divided by computer-generated codes into three parallel groups: (A) patients received a 1 µg.kg-1 remifentanil bolus immediately before induction, followed by 0.15 µg.kg-1.min-1 infusion, that was stopped after skin incision; (B) patients received a 1 µg.kg-1 remifentanil bolus immediately before induction; (C) (control), patients did not receive remifentanil until delivery. Maternal venous blood samples were taken at basal time, at extraction and 30 minutes after the end of operation for spectrophotometrical determination of malondialdehyde and advanced oxidation protein products concentration. The same was conducted for umbilical venous sample. Results: Systolic blood pressure and heart rate remained significantly lower in group A compared to B and C during entire Induction-Delivery period (p < 0.001, p = 0.02 after intubation; p = 0.006, p = 0.03 after skin incision; p = 0.029, p = 0.04 after extraction; respectively). Malondialdehyde concentration was lower at time of extraction in maternal blood in group A compared to B and C (p = 0.026). All neonatal Apgar scores were ≥ 8 and umbilical acid-base values within normal range. Conclusions: The remifentanil dosing regimen applied in group A significantly attenuated lipid peroxidation and maternal hemodynamic response during entire I-D period, without compromising neonatal outcome.

Resumo Justificativa e objetivo: O remifentanil é usado para atenuar a resposta hemodinâmica materna à intubação e ao estresse cirúrgico durante o intervalo indução-parto cesariana. O objetivo foi comparar os efeitos de dois regimes posológicos de remifentanil sobre o nível de estresse oxidativo, em correlação com seus efeitos na hemodinâmica materna e no neonato. Métodos: Mediante códigos gerados por computador, 51 pacientes (17 por grupo) programadas para cesariana eletiva foram randomicamente divididas em três grupos paralelos (A, B e C). No Grupo A, as pacientes receberam remifentanil em bolus de 1 µg.kg-1 imediatamente antes da indução, seguido por infusão de 0,15 µg.kg-1.min-1 que foi interrompida após a incisão da pele; no Grupo B, as pacientes receberam remifentanil em bolus de 1 µg.kg-1 imediatamente antes da indução; no Grupo C (controle), as pacientes não receberam remifentanil até o parto. Amostras de sangue venoso materno foram colhidas no momento basal, na extração do feto e 30 minutos após o término da operação para determinar espectrofotometricamente as concentrações do malondialdeído e dos produtos proteicos de oxidação avançada. O mesmo foi feito para a coleta das amostras de sangue venoso umbilical. Resultados: A pressão arterial sistólica e a frequência cardíaca permaneceram significativamente menores no Grupo A, comparado aos grupos B e C, durante todo o intervalo indução-parto (p < 0,001, p = 0,02 após a intubação; p = 0,006, p = 0,03 após a incisão da pele; p = 0,029, p = 0,04 após a extração do feto, respectivamente). No momento da extração do feto, a concentração do malondialdeído foi menor no sangue materno do Grupo A, comparado aos grupos B e C (p = 0,026). Todos os escores de Apgar neonatais foram ≥ 8 e os valores da avaliação ácido-base do cordão umbilical estavam dentro da faixa normal. Conclusões: O regime posológico de remifentanil aplicado ao Grupo A atenuou de modo significativo a peroxidação lipídica e a resposta hemodinâmica materna durante todo o intervalo indução-parto, sem comprometer o desfecho neonatal.

Magnesium in obstetric anesthesia and intensive care.

Magnesium, one of the essential elements in the human body, has numerous favorable effects that offer a variety of possibilities for its use in obstetric anesthesia and intensive care. Administered as a single intravenous bolus dose or a bolus followed by continuous infusion during surgery, magnesium attenuates stress response to endotracheal intubation, and reduces intraoperative anesthetic and postoperative analgesic requirements, while at the same time preserving favorable hemodynamics. Applied as part of an intrathecal or epidural anesthetic mixture, magnesium prolongs the duration of anesthesia and diminishes total postoperative analgesic consumption with no adverse maternal or neonatal effects. In obstetric intensive care, magnesium represents a first-choice medication in the treatment and prevention of eclamptic seizures. If used in recommended doses with close monitoring, magnesium is a safe and effective medication.

Attenuation of cardiovascular stress response to endotracheal intubation by the use of remifentanil in patients undergoing Cesarean delivery.

The induction-delivery time during Cesarean section is traditionally conducted under light anesthesia because of the possibility of anesthesia-induced neonatal respiratory depression. The serious consequences of such an approach could be the increased risk of maternal intraoperative awareness and exaggerated neuroendocrine and cardiovascular stress response to laryngoscopy, endotracheal intubation, and surgical stimuli. Here, we briefly discuss the various pharmacological options for attenuation of stress response to endotracheal intubation during Cesarean delivery and then focus on remifentanil, its pharmacokinetic properties, and its use in anesthesia, both in clinical studies and case reports. Remifentanil intravenous bolus doses of 0.5-1 µg/kg before the induction to anesthesia provide the best compromise between attenuating maternal stress response and minimizing the possibility of neonatal respiratory depression. Although neonatal respiratory depression, if present, usually resolves in a few minutes without the need for prolonged resuscitation measures, health care workers skilled at neonatal resuscitation should be present in the operating room whenever remifentanil is used.

Posterior reversible encephalopathy syndrome in eclamptic patients: neuroradiological manifestation, pathogenesis and management.

INTRODUCTION: Eclampsia is one of the most serious complications of hypertensive disorders of pregnancy, defined as the occurrence of one or more convulsions superimposed on preeclampsia. Besides the ordinary course of the disease, ranging from a mild to a severe form, with culmination in eclamptic seizures, there is a significant percent of cases where eclampsia starts unexpectedly, without typical premonitory symptoms and signs, which makes it difficult to prevent. NEURORADIOLOGICAL CHARACTERISTICS AND PATHOGENESIS OF ECLAMPSIA. Neuroradiological signs of eclampsia are described as posterior reversible encephalopathy syndrome, and are manifested by nausea, vomiting, headache, visual disturbances, altered mental status, convulsions and coma, together with characteristic findings on computed tomography or magnetic resonance imaging scan of the head, indicating the presence of vasogenic brain edema. The topic of this article are possible mechanisms of the development of posterior reversible encephalopathy syndrome in pregnancy and modalities of acute treatment of this emergency state. MANAGEMENT OF ECLAMPSIA: Magnesium sulphate is nowadays the drug of choice for the treatment and prevention of eclamptic seizures. Labetalol is considered to be the agent of choice in the treatment of hypertensive emergencies of pregnancy, followed by hydralazine, nifedipine, nicardipine, urapidil, nitroglycerin and sodium nitroprusside (in most refractory cases). Angiotensin converting enzyme inhibitors and angiotensin blocking drugs are contraindicated in pregnancy. Captopril and enalapril are allowed during lactation. CONCLUSION: Posterior reversible encephalopathy syndrome in eclamptic patients is completely reversible if adequate diagnosis is promptly made and intensive treatment immediately administered.