The Diverse Effects of Vasopressors on the Fetoplacental Circulation of the Dual Perfused Human Placenta

Minzter, Beth H.; Johnson, Raymond F.; Paschall, Ray L.; Ramasubramanian, R.; Ayers, Gregory D.; Downing, J. W.

doi:10.1213/ane.0b013e3181c91ebc

Cited by 30 publications

(12 citation statements)

References 39 publications

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“…However, norepinephrine restored the decreased peripheral vascular resistance less than phenylephrine [9]. In 2010, Minzter et al [36] reported that norepinephrine had no effect on fetal arterial perfusion pressure and fetoplacental microcirculation was not compromised. In the present study, no difference in fetal umbilical artery PO 2 was detected, suggesting that norepinephrine might not compromise fetal oxygen supply when compared with ephedrine in a bolus regimen.…”

Section: Discussionmentioning

confidence: 99%

A Comparative Study of Bolus Norepinephrine, Phenylephrine, and Ephedrine for the Treatment of Maternal Hypotension in Parturients with Preeclampsia During Cesarean Delivery Under Spinal Anesthesia

et al. 2019

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BackgroundThis study aimed to compare the efficacy and safety of bolus norepinephrine, phenylephrine, and ephedrine in parturient with preeclampsia who had hypotension during cesarean delivery under spinal anesthesia.Material/MethodsOne hundred and sixty-six parturient women with preeclampsia who had a baseline systolic blood pressure (SBP) <80% during spinal anesthesia for cesarean section were divided into three treatment groups; bolus norepinephrine 4 μg (group N) (n=56), phenylephrine 50 μg (group P) (n=55), and ephedrine 4 mg (group E) (n=55). Primary outcomes included overall SBP and heart rate (HR) until delivery. Secondary outcomes included the incidence of tachycardia (HR >120 bpm), bradycardia (HR <60 bpm), hypertension (SBP >120% baseline), number of boluses of vasopressor required and episodes of hypotension, maternal side effects, and neonatal outcome.ResultsOverall HR in group N was significantly increased compared with group P (80.5±12 vs. 76.6±6.9 bpm; P=0.04), and significantly lower compared with group E (80.5±12 vs. 84.9±7.1 bpm; P=0.02). Parturients in group N had fewer episodes of bradycardia compared with group P (3.6% vs. 21.8%; RR=0.26l; 95% CI, 0.07–0.73; P=0.004) and fewer episodes of tachycardia compared with group E (16.1% vs. 36.4%; RR 0.54; 95% CI, 0.29–0.90; P=0.02).ConclusionsA bolus dose of norepinephrine showed similar efficacy to phenylephrine but improved maternal and neonatal safety in parturients with preeclampsia with hypotension during cesarean section under spinal anesthesia.

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Section: Discussionmentioning

confidence: 99%

A Comparative Study of Bolus Norepinephrine, Phenylephrine, and Ephedrine for the Treatment of Maternal Hypotension in Parturients with Preeclampsia During Cesarean Delivery Under Spinal Anesthesia

et al. 2019

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“…Minzter et al . [ 11 ] reported that norepinephrine had no effect on fetal arterial perfusion pressure, and the fetoplacental microcirculation was not compromised.…”

Section: Introductionmentioning

confidence: 99%

Norepinephrine versus ephedrine to maintain arterial blood pressure during spinal anesthesia for cesarean delivery: A prospective double-blinded trial

Elnabtity

Selim

2018

Anesth Essays Res

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Background:Ephedrine was conventionally regarded as the first-choice drug to maintain maternal blood pressure during spinal anesthesia for cesarean delivery, due to its stimulant activity on α- and β-adrenergic receptors. Norepinephrine is a weak β-adrenergic and potent α-adrenergic receptor agonist. Therefore, it may be suitable for maintaining blood pressure with less chronotropic effects compared to ephedrine.Patients and Methods:One hundred and forty healthy patients having cesarean delivery under spinal anesthesia were randomized to Group N (n = 61) who received a prophylactic bolus of norepinephrine 5 μg intravenous (i.v.) at the time of intrathecal block or Group E (n = 61) who received a prophylactic bolus of i.v. ephedrine 10 mg. Rescue i.v. bolus interventions of norepinephrine 5 μg or ephedrine 10 mg were given as required to maintain systolic blood pressure. Maternal and fetal hemodynamic variables, Apgar score, and number of boluses of vasopressors used were recorded.Results:The numbers of maternal hypotension and hypertension episodes and the frequency of bradycardia and tachycardia were significantly lower in Group N compared with Group E (P = 0.02, 0.003, 0.0002, and 0.008, respectively). The number of boluses of vasopressors used was also lower in Group N (P = 0.005). Uterine artery pulsatility index was lower in Group N compared to Group E (P = 0.01) when measured 5 min after spinal anesthesia. Moreover, it was higher at 5 min in Group E when compared with the baseline readings in the same group (P = 0.001).Conclusions:Norepinephrine is a suitable and potent drug to counterbalance the hemodynamic effects of spinal anesthesia during cesarean delivery.

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“…In addition, the effect of methoxamine on uteroplacental flow is also controversial. Wright et al demonstrated that methoxamine was associated with significant increase in uteroplacental resistance and flow [ 15 ], whereas Mintzer et al showed methoxamine had no effect on uterine blood flow and the fetal arterial perfusion pressure [ 27 ]. Because these side effects of methoxamine in obstetrics are potential and controversial, we think it is also safe for obstetric patients.…”

Section: Discussionmentioning

confidence: 99%

A randomised dose-response study of prophylactic Methoxamine infusion for preventing spinal-induced hypotension during Cesarean delivery

Tang

Chen

et al. 2020

BMC Anesthesiol

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Background: α-receptor agonists have been reported to be safe and effective for treating or preventing spinalinduced hypotension during cesarean delivery. As a pure α 1 adrenergic agonist, methoxamine has potential advantages of reducing myocardial oxygen consumption and protecting the heart in obstetric patients compared to phenylephrine. The aim of this study was to determine the optimal prophylactic methoxamine infusion dose that would be effective for preventing spinal-induced hypotension in 50% (ED 50) and 95% (ED 95) of parturients. Methods: Eighty parturients with a singleton pregnancy scheduled for elective cesarean delivery were randomly allocated to receive prophylactic methoxamine infusion at one of four different fixed-rates: 1 μg/kg/min (group M1), 2 μg/kg/min (group M2), 3 μg/kg/min (group M3), or 4 μg/kg/min (group M4). An adequate response was defined as absence of hypotension (maternal SBP < 80% of baseline or SBP < 90 mmHg). The values for ED 50 and ED 95 of prophylactic methoxamine infusion were determined by probit regression model. The outcomes of maternal hemodynamics and fetal status were compared among the groups. Results: The calculated ED 50 and ED 95 (95% confidence interval) of prophylactic methoxamine infusion dose were 2.178 (95% CI 1.564 to 2.680) μg/kg/min and 4.821 (95% CI 3.951 to 7.017) μg/kg/min, respectively. The incidence of hypotension decreased with increasing methoxamine infusion dose (15/20, 11/20, 7/20 and 2/20 in group M1, M2, M3 and M4 respectively, P < 0.001). 1-min Apgar scores and umbilical arterial PaO2 were lower but umbilical arterial PaCO2 was higher in Group M1. No difference was found in the other incidence of adverse effects and neonatal outcomes among groups. Conclusions: Under the conditions of this study, when prophylactic methoxamine infusion was given at a fixedrate based on body weight for preventing spinal-induced hypotension in obstetric patients, the values for ED 50 and ED 95 were 2.178 μg/kg/min and 4.821 μg/kg/min respectively.

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The Diverse Effects of Vasopressors on the Fetoplacental Circulation of the Dual Perfused Human Placenta

Cited by 30 publications

References 39 publications

A Comparative Study of Bolus Norepinephrine, Phenylephrine, and Ephedrine for the Treatment of Maternal Hypotension in Parturients with Preeclampsia During Cesarean Delivery Under Spinal Anesthesia

A Comparative Study of Bolus Norepinephrine, Phenylephrine, and Ephedrine for the Treatment of Maternal Hypotension in Parturients with Preeclampsia During Cesarean Delivery Under Spinal Anesthesia

Norepinephrine versus ephedrine to maintain arterial blood pressure during spinal anesthesia for cesarean delivery: A prospective double-blinded trial

A randomised dose-response study of prophylactic Methoxamine infusion for preventing spinal-induced hypotension during Cesarean delivery

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