Prevention Of Maternal Hypotension Research Articles

Phenylephrine and Ephedrine for Prevention of Hypotension in Women during Lower Segment Caesarean Section under Spinal Anaesthesia: A Randomised Clinical Study

Introduction: Hypotension is the most common serious adverse event associated with Spinal Anaesthesia (SA) and is associated with nausea and vomiting leading to pulmonary aspiration, respiratory depression and cardiac arrest. Phenylephrine (PE) and Ephedrine (EP) are vasopressors commonly used for prevention of hypotension associated with SA. Aim: To compare the efficacy and safety of PE and EP in prevention of hypotension induced by SA in women during Lower Segment Caesarean Section (LSCS) surgery. Materials and Methods: The present randomised clinical study was conducted on 60 women, between 18-36 years of age and a Heart Rate (HR) of 60-100 per minute randomised to receive either 100 mcg Intravenous (i.v.) bolus of PE, or 12 mg i.v. of EP during intrathecal block. Women having intraoperative hypotension were injected additional doses of vasopressor. Cardiovascular parameters were recorded at baseline (before block) and then at 1, 5, 10, 15, 30, 40 and 60 minutes. Further, safety was also assessed based on hypotension events and adverse events reported during immediate postoperative period. Data analysis was done using IBM SPSS 17 and a p-value <0.05 was considered statistically significant. Results: The mean age of the study participants in PE and EP group was 26.67±5.40 and 26.23±4.59 years, respectively. Significant differences were observed between PE and EP groups for change in Systolic Blood Pressure (SBP) after 1, 10, 30, 40 and 60 minutes. Overall, there was a slight fall in SBP with PE, whereas, with EP there was a slight rise in SBP. Also, the Diastolic Blood Pressure (DBP) was maintained with EP throughout the 60 minute period, whereas with PE there was an initial rise in DBP followed by a slight fall in DBP. The Mean Arterial Pressure (MAP) was well maintained with PE throughout, whereas with EP there was a fall in MAP after 15 minutes. However, these changes were not clinically significant. The Pulse Rate (PR) was lower with PE compared to EP group at time points of 1, 5, 15 and 20 minutes. The mean respiratory rates and blood oxygen saturation were similar with PE and EP administration (p>0.05). A total of 13 (43.3%) patients in the PE group and 14 (46%) in the EP group had adverse events excluding hypotensive patients. Conclusion: According to the findings of the present study, the i.v. bolus of 100 mcg PE and 12 mg EP administered immediately after SA are equally effective in prevention of maternal hypotension and do not cause any significant cardiovascular and respiratory effects.

Manual Leftward Displacement of the Uterus in the Prevention of Maternal Hypotension During Cesarean Section: A Randomized Comparative Study

Background: It is essential to maintain the hemodynamic state of mothers during delivery in cesarean section (CS). Research has shown that hypotension can be controlled by applying a 15° left lateral tilt. This can be achieved using an obstetric wedge or by tilting the operating table leftward. A systematic review of further research shows insufficient evidence to suggest whether it is effective or practical. Objectives: This study aims to evaluate the effectiveness of manual left tilting of the uterus on maintaining the hemodynamic status of mothers undergoing a CS delivery, where a spinal anesthetic has been given. Methods: Seventy women who were candidates for CS deliveries were randomly assigned into 2 groups as follows: group 1, the anaesthesiologist manually maneuvered the mother’s uterus to the left shortly after spinal anesthesia; group 2, the mothers’ uteruses were not displaced to the left. Sixty-seven of 70 participants completed the study. The hemodynamic status of the mother was reported before, during, and after surgery. The total doses of inotropic-vasopressors used to maintain hemodynamic stability were recorded. Results: The mother’s age, vital signs, and body mass index (BMI) before pregnancy and near term were not significantly different. Mothers maintained a significantly higher systolic blood pressure (SBP) when the uterus was displaced to the left (group 1). The mothers also required less ephedrine. Mothers in group 2 suffered a greater decrease in their SBP both after induction and before incision of the abdomen (group 2, P < 0.05). Conclusions: The manual tilting of the uterus to the left during CS is effective in maintaining blood pressure and decreases the need for vasopressors.

Comparison of Prophylactic Phenylephrine Infusion Versus Intravenous Ondansetron on Hypotension During Spinal Anesthesia for Cesarean Section

Multiple methods have been proposed to prevent the incidence of hypotension in women undergoing cesarean section under spinal anesthesia. This study was conducted to compare the efficacy of phenylephrine (50 μg.min-1) versus ondansetron (8 mg) in the prevention of such complications. We included a total of 184 full-term pregnant women who were randomly divided into two groups: Group P included 92 cases who were commenced on phenylephrine infusion (50 μg.min-1 given after puncture) and Group O included the other 92 cases who were administered ondansetron (8 mg given 5 min before puncture). Demographic data were not significantly different between the two groups. Maternal hypotension was significantly more encountered in the ondansetron group (51.6% vs. 22%) and ephedrine was used more significantly in that group (19.8% vs. 8.8%). In addition, nausea and skin flushing were more commonly encountered in the same group. The incidence of vomiting and patient discomfort was not significantly different between the two study groups. Phenylephrine is markedly superior to ondansetron in the prevention of maternal hypotension and vasopressor need during cesarean section under spinal anesthesia.

Crystalloid preload versus crystalloid co-load for hypotension in parturients undergoing caesarean section under spinal anaesthesia

Abstract Though hypotension is a common complication after spinal anaesthesia, preloading with crystalloids may not be able to prevent it. We aimed to compare the efficacy of crystalloid preload and co-load for the prevention of maternal hypotension in parturients undergoing caesarean section under spinal anaesthesia. Seventy parturients, aged 20 to 40 years of American Society of Anaesthesiologist (ASA) physical status 1/II, scheduled for caesarean section under spinal anaesthesia were divided into two groups. Parturients in group P received 15 ml/kg of ringer's lactate as preload over 20 min before the intrathecal drug administration. Parturients in group C received 15 ml/kg of ringer's lactate over 20 min, just after intrathecal drug administration. Incidence of hypotension, systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, the requirement of ephedrine, and any complications was recorded. 25 (71%) parturients in group P and 15 (42%) parturients in group C developed statistically significant hypotension. 21 (59%) parturients developed nausea and vomiting in group P as compared to 9 (25%) parturients in group C which were statistically significant. The mean number of doses of ephedrine required in group P was 1.8±0.6 and 0.9±0.7 in group C which was statistically significant. The total dose of ephedrine used in group P was 9.6±3.4mg and 5.9± 2.1mg in group C which was statistically significant. Co-loading with 15 ml/ kg of crystalloid-like ringer's lactate was more effective than preloading in preventing spinal-induced maternal hypotension, thereby reducing ephedrine requirement and avoiding complications. Keywords: Anaesthesia, Co-load, Hypotension, Preload, Spinal, Caesarean section.

Prevention of hypotension during elective cesarean section with a combination of colloid co-load and a continuous infusion of a vasoconstrictive agent: A comparative randomized study

Background: Spinal anesthesia is considered the anesthetic technique of choice in cesarean section but it can be frequently complicated by hypotension, with occasionally serious consequences for both the mother and fetus. One of the standard techniques used in the prevention of maternal hypotension is the administration of a continuous phenylephrine infusion. However, phenylephrine can lead to baroreceptor-mediated reflex bradycardia with untoward consequences for the maternal cardiac output. Nowadays, noradrenaline has been proposed as an alternative agent in this context, since due to its additional weak dose-dependent β-action, it can be associated with an inferior incidence of maternal bradycardia and thus of propensity to decrease the cardiac output. Colloid co-hydration has also been proven to be an effective technique in the prevention of maternal hypotension. This double-blinded, prospective randomized study aimed to investigate whether the addition of a fixed rate phenylephrine infusion or noradrenaline infusion to a colloid co-hydration regimen results in better maternal hemodynamic status or in a more favorable metabolic profile in the newborn as compared to the administration of colloids alone without any vasoconstrictor during elective cesarean section under combined spinal-epidural anesthesia. Materials and methods: One hundred-twenty parturients were randomized to either phenylephrine 50 μg/min (group P) or noradrenaline 4 μg/min (group N) or placebo (group C). All infusions had been prepared in identical syringes and the infusion rate was 30 mL/h in order to ensure the “blindness” of the study. As soon as the spinal injection started, all groups were administered 10 mL/kg of hydroxyethyl starch (HES) solution simultaneously with the onset of vasoconstrictor infusion. The primary end-point of the study was the incidence of maternal hypotension (SAP <80% of baseline). Additionally, maternal hemodynamics at specific time-points were recorded using non-invasive technology (Edwards Lifesciences ClearSight System) as well as the incidence of reactive hypertension, bradycardia, the requirement for bolus vasoconstrictor administration and the fetal acid-base status, the umbilical venous and arterial blood gases and the newborn Apgar score. Results: The incidence of maternal hypotension was higher in group C than in group P and also higher in group C than in group N (p = 0.024 and 0.073, respectively). The need of bolus administration of vasoconstrictor was higher in group C than in group P and also higher in group C than in group N (p = 0.001 and 0.003, respectively). The incidence of bradycardia was higher in group P than in group N (p = 0.018). The incidence of reactive hypertension was higher in group P than in group N and also higher in group P than in group C (p = 0.029 and 0.005, respectively). The need of modification of the infusion rate was higher in group P than in group N and also higher in group P than in group C (p < 0.001 και p = 0.002, respectively). The fetal pH of the umbilical vein was higher in groups N and P than in group C (p < 0.001), the fetal pO2 of the umbilical vein was higher in group N than in group C (p = 0.023) and fetal blood glucose concentration was higher in group N than in group C (p = 0.025) as well as in group N than group P with no statistical significance. Higher systematic vascular resistance index (SVRI) and higher SAP were observed at specific time-points in group P versus the other two groups. Finally, post-delivery Apgar scores were similar in all groups. Conclusions: The combination of a fixed-rate infusion of noradrenaline with the co-administration of colloid seems to be the most effective in the obstetric management of the parturient during cesarean section under regional anesthesia since it ensures maternal hemodynamic stability and a favorable metabolic profile in the newborn. This regimen seems to be superior to either a combination of colloid co-administration with a fixed rate of phenylephrine or to the administration of colloid alone without any vasoconstrictor agent. The higher concentration of fetal blood glucose in group N might be due to a catecholamine-induced glucose metabolism activation and due to a β-receptor-mediated decrease of insulin release.

Enhanced recovery after cesarean delivery: a challenge for anesthesiologists.

Enhanced recovery after cesarean (ERAC) delivery is an evidence-based, multi-disciplinary approach throughout pre-, intra-, post-operative period. The ultimate goal of ERAC is to enhance recovery and improve the maternal and neonatal outcomes. This review highlights the role of anesthesiologist in ERAC protocols. This review provided a general introduction of ERAC including the purposes and the essential elements of ERAC protocols. The tool used for evaluating the quality of ERAC (ObsQoR-11) was discussed. The role of anesthesiologist in ERAC should cover the areas including management of peri-operative hypotension, prevention and treatment of intra- and post-operative nausea and vomiting, prevention of hypothermia and multi-modal peri-operative pain management, and active pre-operative management of unplanned conversion of labor analgesia to cesarean delivery anesthesia. Although some concerns still remain, ERAC implementation should not be delayed. Regular assessment and process improvement should be imbedded into the protocol. Further high-quality studies are warranted to demonstrate the effectiveness and efficacy of the ERAC protocol.

Assessment of the effect of two doses of prophylactic onandsetron on maternal hemodynamics, neonatal outcome and spinal blockade specifications, in parturients scheduled for cesarean delivery

Objective To compare between two doses of ondansetron (2 mg, 4 mg) and ephedrine in prevention of maternal hypotension and bradycardia induced by spinal anesthesia, their effects on specifications of spinal blockade, neonatal outcome, and their side effects. Patients and methods One hundred twenty parturients ASA І or ІІ aged between 18 and 40 years, scheduled for elective cesarean section under spinal anesthesia. They were randomly divided into four equal groups. First group received intravenous I.V. 2 mg ondansetron, second group received I.V. 4 mg ondansetron, third group received 10 mg ephedrine, and the fourth group received normal saline. All the test drugs were administered as bolus dose five minutes before intrathecal injection. Mean blood pressure, heart rate, vasopressor use, spinal anesthesia specifications, neonatal outcome, and side effects were assessed. Results The fall in mean blood pressure after spinal anesthesia in ondansetron 4 mg group was the least and the greatest was in the control group. There was dropping in heart rate values after spinal anesthesia started from 5 minutes value with significance to the control group only. No significant difference between the four groups in the spinal anesthesia characters. Slight acidosis was noticed in the ephedrine group which doesn’t affect the clinical neonatal outcome. Conclusion Prophylactic bolus intravenous ondansetron 4 mg and to less extent 2 mg could decrease the fall in mean blood pressure of parturients following spinal anesthesia as well as intravenous ephedrine 10 mg with added advantage that it could decrease neonatal acidosis associated with ephedrine use.

Maternal care bundle: The effect of a multimodal approach on the prevention of maternal hypotension following spinal anesthesia in parturients undergoing elective or urgent cesarean section

Background and AimMany techniques to prevent spinal induced hypotension in cesarean section have been advocated; but no one technique proved to be totally effective. The aim of this cohort interventional study was to investigate the efficacy of application of multimodal approach to decrease the incidence of hypotension (defined as mean arterial blood pressure ⩽60 mmHg) following spinal anesthesia in parturients undergoing elective or urgent cesarean section.Patients and MethodsIn this prospective cohort interventional study, 159 American Society of Anesthesiologists (ASA) classification I–II parturients undergoing elective or urgent cesarean section were enrolled. All patients received maternal care bundle which consisted of; fixed low dose of bupivacaine (7.5 mg + fentanyl 25 μg), coloading with 15 ml/kg lactated Ringer’s, placement of the patient in the supine wedged position, administration of 9 mg ephedrine sulphate IV after intrathecal injection and placement of graduated compression stockings (GCS) in the elevated leg position >45° and maintaining leg elevation at 20° following application of GCS. Demographic data, spinal anesthetic technique variables, fluid intake and urine output were documented. Mean arterial blood pressure, heart rate and oxygen saturation were recorded at baseline T0 (before spinal anesthesia administration), T1 (5 min following intrathecal injection of local anesthetics), T2 (15 min), T3 (30 min) and at T4 (end of procedure prior to PACU transfer). Total dose of ephedrine and any complication was documented.ResultsIncidence of hypotension after 5 min (T1) was 17.6%, at 15 min (T2) was 3.8% and at 30 min (T3) was 5%.ConclusionsThe application of a maternal care bundle had significantly decreased the incidence of spinal induced hypotension in parturient undergoing elective or urgent Cesarean delivery.

Optimal dose of phenylephrine infusion for management of maternal hypotension under spinal anaesthesia during caesarean delivery

Phenylephrine is the drug presently recommended for prevention of maternal hypotension during caesarean section. The optimal infusion dose is still undetermined. We tried to determine the optimal infusion dose of phenylephrine to prevent maternal hypotension. After Institutional Ethical committee approval, consenting one hundred ASA physical status I or II parturients for elective caesarean delivery were included randomized into 4 groups of 25 each by picking lots. Group P25, P50, P75 and P100 received phenylephrine infusion in concentrations of 25, 50, 75 and 100µg/ min respectively. After administering spinal anaesthesia a infusion was started as per group allocation. 20% change in baseline mean blood pressure was taken for intervention. Hypotension was treated with 50µg phenylephrine bolus, bradycardia treated with atropine 0.6 mg. Hypertension treated by stopping the infusion. Neonatal Apgar at 1 and 5 minutes and base deficit in cord blood was assessed. Demographic, anaesthetic and surgical characteristics were comparable. 25% of patients in group P25 had hypotension requiring bolus phenylephrine dose. 40% in group P75 and 55% in group P100 had hypertension requiring infusion to be stopped. 6 patients in group P75 and 9 patients in group P100 required atropine to treat bradycardia. Neonatal outcome were comparable in 4 groups. Conclusions: Phenylephrine in an infusion dose of 50µg/min gives stable haemodynamics with good neonatal outcome.

Comparative evaluation of co-loading versus preloading for prevention of post-spinal hypotension in elective caesarean section

Aims and Objectives: The aim of the present study was to study the effectiveness of co-loading of crystalloid over preloading of crystalloid in prevention of maternal hypotension during spinal anaesthesia for elective caesarean section. Material and Methods: Hundred parturients aged 18-35 yrs undergoing elective caesarean section were randomly allocated in two groups of fifty each. Group P received preload of 20ml/kg of ringer’s lactate solution over a period of 20 minutes before spinal anaesthesia, while Group C received co-load of 20ml/Kg of ringer’s lactate solution at the maximal possible rate by pressurized giving set at the time of administration of spinal anaesthesia. Both the groups received spinal anaesthesia using 2ml of 0.5% hyperbaric bupivacaine at L3-4 level with 23G Quinke’s spinal needle. Blood pressure measurements were recorded in both the groups at 2min interval from the start of the regional block for the first 10 min and then at 5min interval till 30min and thereafter every 15min till the end of surgery. Similarly other parameters like heart rate, SPO2, maximum level of sensory block and APGAR scores were also recorded. Statistical Analysis: Chi-square test was used to find the significance of study parameters on categorical scale between groups. Z test was used to find the significance of study parameters on continuous scale between two groups (intergroup analysis) on metric parameters. Significance was assessed at 5 % level of significance. Any p – value less than 0.05 (p

Prophylactic ondansetron for prevention of maternal hypotension following spinal anesthesia in women undergoing cesarean section: a systematic review protocol.

REVIEW QUESTION / OBJECTIVE The objective of this review is to synthesize the best available evidence on the effectiveness of ondansetron given prophylactically prior to spinal anesthesia on attenuating hypotension in women undergoing elective cesarean section. The specific review question is as follows: In women undergoing spinal anesthesia for elective cesarean section, what is the effectiveness of prophylactic ondansetron on preventing hypotension, compared to placebo? INCLUSION CRITERIA Types of participants The review will consider all quantitative studies that include parturients, of any ethnicity, undergoing spinal anesthesia for elective cesarean delivery. Studies that focus on any other surgeries other than cesarean section and anesthesia modes other than spinal anesthesia (general anesthesia or epidural anesthesia) will be excluded. Furthermore, any study with parturients not undergoing cesarean section or undergoing emergent cesarean section will also be omitted. Lastly, it is important to exclude studies that include subjects with hypertensive disorders of pregnancy, because this population may meet hypotension criteria less frequently. Types of intervention(s)/phenomena of interest This review will only consider studies of ondansetron administered intravenously for the prevention of hypotension in subjects requiring spinal anesthesia for elective cesarean section. More precisely, the goal of this review is to identify if prophylactic administration of ondansetron is more effective than a placebo in preventing hypotension after spinal anesthesia. All variations of ondansetron dosages and their duration of administration will be included. Differences in anesthetic technique across studies, including the variations in armamentarium and dosing strategies are beyond the goal of the review question under inquiry, TRUNCATED AT 250 WORDS

Prophylactic ondansetron for prevention of maternal hypotension following spinal anesthesia in women undergoing cesarean section: a systematic review protocol

Prophylactic ondansetron for prevention of maternal hypotension following spinal anesthesia in women undergoing cesarean section: a systematic review protocol

Prevention of maternal hypotension during elective caesarean section under spinal anaesthesia with an intermittent pneumatic compression system in lower extremities: preliminary study

Puyo, M.1; Garcia-Orellana, M.2; González-Núñez, M.1; Manrique, S.3; Suescun, M. C.3; Trillo, L.2 Author Information

Fluid and Vasopressor Management for Cesarean Delivery Under Spinal Anesthesia

The purpose of this Continuing Professional Development module is to review the physiology of maternal hypotension induced by spinal anesthesia in pregnant women, and the effects of fluids and vasopressors. Maternal hypotension induced by spinal anesthesia is caused mainly by peripheral vasodilatation and is not usually associated with a decrease in cardiac output. Although the intravenous administration of fluids helps to increase cardiac output, it does not always prevent maternal hypotension. Three strategies of fluid administrations are equivalent for the prevention of maternal hypotension and a reduced need for vasopressors: (1) colloid preload; (2) colloid coload; and (3) crystalloid coload. Crystalloid preload is not as effective as any of those three strategies. Unlike phenylephrine, ephedrine can cause fetal acidosis. Therefore, phenylephrine is recommended as first line treatment of maternal hypotension. A phenylephrine infusion (25-50 μg·min−1) appears to be more effective than phenylephrine boluses to prevent hypotension, and nausea and vomiting. In pre-eclamptic patients, spinal anesthesia produces less hypotension than in normal pregnant women and fluid volumes up to 1,000 mL are usually well tolerated. Therefore mild to moderate intravascular volume loading is recommended, keeping in mind the increased risk for pulmonary edema in this population. In pre-eclamptic patients, hypotension can be treated either with ephedrine or phenylephrine, and phenylephrine infusions are not recommended. A volume loading regimen other than crystalloid preload should be adopted. A phenylephrine infusion during elective Cesarean delivery is beneficial for the mother and safe for the newborn.

Préremplissage par HEA 130/0,4 versus sérum salé isotonique dans la prévention de l’hypotension au cours de la rachianesthésie pour césarienne programmée

ObjectiveTo evaluate the efficacy of HES 130/0.4 preload compared to normal saline solution for prevention of hypotension during spinal anaesthesia for elective caesarean section. Study designProspective, randomized. Patients and methodsSixty ASA I patients scheduled for elective caesarean section were randomized to receive either 1000mL of normal saline solution preload (Group C) or 500mL of HES 130/0.4 preload (Group V) within 15minutes prior to spinal anaesthesia. Spinal anaesthesia techniques and ephedrine administration was standardized in both groups. The primary endpoint was the incidence of maternal hypotension before fetal extraction. ResultsThe incidence of hypotension before fetal extraction was significantly lower in group V compared to group C (40% vs 66%, P=0.03). Ephedrine consumption was significantly lower in group V (7.6±13mg vs 16.4±15mg). Lowest systolic blood pressure was significantly higher in group V (96±14 vs 85±14mmHg, P=0.005). Incidence of adverse maternal effects and neonatal consequences were similar in both groups. ConclusionHES 130/0.4 preload reduced the incidence of hypotension, the duration of longest hypotension, and the need for ephedrine during spinal anaesthesia for elective caesarean section. However, the efficacy of HES 130/0.4 alone in prevention of maternal hypotension during spinal anaesthesia for caesarean section is still insufficient.

Prevention of Maternal Hypotension After Regional Anaesthesia for Cesarean Section

Survey of Anesthesiology: February 2011 - Volume 55 - Issue 1 - p 24-34 doi: 10.1097/01.SA.0000391285.41852.7d

Comparison of phenylephrine hydrochloride and mephentermine sulphate for prevention of post spinal hypotension

This study compared the effects of intravenous infusions of phenylephrine and mephentermine on the prevention of maternal hypotension and neonatal outcome in patients receiving spinal anaesthesia for caesarean section. Sixty ASA 1-2 patients with term, uncomplicated singleton pregnancy undergoing caesarean section under spinal anaesthesia were randomly divided into two groups of 30 each, to receive a prophylactic intravenous infusion of either phenylephrine or mephentermine. The incidence of hypotension was statistically similar in the two groups. However, in patients receiving phenylephrine, 7 (23%) developed bradycardia and 6 (20%), reactive hypertension. Neonatal outcome, in terms of Apgar scores and umbilical artery pH, was similar in both the groups. To conclude, phenylephrine and mephentermine infusions are equally effective in preventing post spinal hypotension in patients undergoing caesarean section and are associated with a similar neonatal outcome.

Prevention of maternal hypotension after regional anaesthesia for caesarean section

Hypotension during regional anaesthesia for caesarean section remains a common clinical problem, particularly for spinal anaesthesia. The purpose of this review is to evaluate recent research in this area with a focus on English language papers from the past 1-2 years. Risk factors for hypotension include increased sympathetic tone, increasing age, obesity, higher blocks and higher birthweight, but not multiple gestation. Methods aimed at countering effects of aortocaval compression do not reliably prevent hypotension. Intravenous crystalloid prehydration has poor efficacy, and focus has changed toward cohydration and use of colloids. Phenylephrine is established as a first-line vasopressor, although there are limited data from high-risk patients. Initial phenylephrine bolus dose requirement may be surprisingly large. Phenylephrine infusions can be conveniently titrated to maintain blood pressure and prevent maternal symptoms. Ephedrine crosses the placenta more than phenylephrine and direct fetal effects of ephedrine may explain associated depression of fetal pH and base excess. Recent research supports decreased use of crystalloid prehydration and ephedrine and increased use of cohydration, colloids, smaller spinal doses and phenylephrine. Further research is required to investigate these techniques in high-risk patients and to evaluate novel monitoring techniques.

Prevention of maternal hypotension by epidural administration of ephedrine sulfate during lumbar epidural anesthesia for cesarean section

OBJECTIVE: Our purpose was to determine whether epidural administration of ephedrine sulfate simultaneously with induction of lumbar epidural anesthesia for nonemergency cesarean section reduces the incidence of maternal hypotension. STUDY DESIGN: In a double-blinded, placebo-controlled trial, 50 normotensive, nonlaboring, American Society of Anesthesiologists' class I or II women with term, uncomplicated, singleton pregnancies were randomly assigned to have normal saline solution or ephedrine sulfate administered epidurally and coincidentally with induction of lumbar epidural anesthesia for nonemergency cesarean section. All subjects were prehydrated with 25 ml/kg crystalloid and placed in supine position on a 15-degree, right-sided wedge before and after induction. Serial blood pressures were compared with baseline blood pressures, chosen as the average of three preinduction blood pressures. Hypotension was defined as a decline in systolic blood pressure to ≤90 mm Hg or ≤70% of baseline. Differences between groups were analyzed by Fisher's Exact Test. Significance was determined at p < 0.05. RESULTS: The incidence of hypotension in the control group was 24%, which was not significantly different from the incidence of 32% in the treated group. CONCLUSION: Prophylactic epidural administration of ephedrine sulfate does not reduce the incidence of maternal hypotension after lumbar epidural anesthesia for nonemergency cesarean section. (Am J Obstet Gynecol 1996;175:985-90.)

Phenylephrine in the prevention of hypotension following spinal anesthesia for cesarean delivery

Study Objective: Phenylephrine and ephedrine were compared in the prevention of maternal hypotension following spinal anesthesia for elective cesarean delivery. Design: Randomized, double-blind trial. Setting: Obstetric suite at a university-affiliated hospital. Patients: Sixty healthy patients electively scheduled for cesarean delivery under spinal anesthesia. Interventions: Patients were randomly assigned to receive either ephedrine (n = 29) in 10 mg intravenous (IV) bolus injections or phenylephrine (n = 31) in 80 μg IV bolus injections to maintain systolic blood pressure (SBP) above 100 mmHg. Measurements and Main Results: Maternal venous, umbilical artery, and umbilical vein blood gases were measured, and neonatal Apgar scores and Early Neonatal Neurobehavior Scale scores were assessed. In the ephedrine group, umbilical artery pH was 7.28 ± 0.01 (mean ± SEM), umbilical artery partial pressure of carbon dioxide (PCO 2) was 56.6 ± 1.4 mmHg, and umbilical artery base deficit was 2.2 ± 0.04 meq. In the phenylephrine group, umbilical artery pH was 7.32 ± 0.01, umbilical artery PCO 2 was 52.1 ± 1.3 torr, and umbilical artery base deficit was 0.38 ± 0.35 meq. There were significant differences between the groups in mean umbilical artery pH, PCO 2 and base deficit, although all values obtained were within normal limits. There were no significant differences between the groups in the remaining acid-base values, neonatal Apgar scores, Early Neonatal Neurobehavior Scale scores, or frequency of maternal nausea and vomiting. Conclusions: Phenylephrine is as effective as ephedrine in the treatment of maternal hypotension, and when used in small incremental bolus injections, it appears to have no adverse neonatal effects in healthy, nonlaboring parturients.