|Year : 2017 | Volume
| Issue : 4 | Page : 226-234
Comparison between prophylactic infusion of ephedrine and lower extremity compression in the prevention of postspinal hypotension during elective cesarean delivery
Haidy S Mansour MD , Ahmed Zein Elabdein Mohamed
Anesthesia and Intensive Care Department, Minia University Hospital, Minia, Egypt
|Date of Submission||16-Sep-2016|
|Date of Acceptance||21-Mar-2017|
|Date of Web Publication||11-Oct-2017|
Haidy S Mansour
Anesthesia and Intensive Care Department, Minia University Hospital, Minia
Source of Support: None, Conflict of Interest: None
Hypotension during spinal block for cesarean section is secondary to the aortocaval compression by the uterus and sympathetic blockade and it can be deleterious to both the fetus and the mother. In this study, we compared the effect of leg wrapping, low-dose ephedrine infusion, and placebo on systolic blood pressure (SBP) during spinal block for cesarean section.
Patients and methods
In this randomized, double-blinded, placebo-controlled study, 90 American Society of Anesthesiology I and II women scheduled for elective cesarean section received either ephedrine (group E; n=29; initial bolus of 5 mg and infusion of 1.5 mg/min), leg wrapping (group L; n=30), or no treatment (group C; n=29). SBP and maximal decrease in SBP were the primary outcomes, and heart rate, neonatal acid–base status, Apgar score, and side effect as bradycardia, neausea, and vomiting were secondary outcome variables during the first 20 min after induction of spinal anesthesia.
Fall in blood pressure in group C was more significant as compared with groups E and L (P<0.05). The incidence of hypotension was significantly lower in group C than in groups E and L (P=0.004 and 0.02, respectively). The incidence of bradycardia showed a significant difference between group E and both group L and group C (P=0.04 and 0.001, respectively). Nausea, vomiting, the umbilical blood gases, and Apgar scores in the first and fifth minute did not show significant differences between the three groups (P>0.05).
An initial bolus of ephedrine followed by a low-dose ephedrine infusion was superior to leg wrapping and no intervention for the prevention of hypotension during spinal anesthesia for cesarean delivery. Leg wrapping prevented hypotension compared with no intervention by limiting modest early spinal anesthesia-mediated venodilation.
Keywords: cesarean delivery, ephedrine infusion, lower extremity compression, postspinal hypotension
|How to cite this article:|
Mansour HS, Mohamed AE. Comparison between prophylactic infusion of ephedrine and lower extremity compression in the prevention of postspinal hypotension during elective cesarean delivery. Res Opin Anesth Intensive Care 2017;4:226-34
|How to cite this URL:|
Mansour HS, Mohamed AE. Comparison between prophylactic infusion of ephedrine and lower extremity compression in the prevention of postspinal hypotension during elective cesarean delivery. Res Opin Anesth Intensive Care [serial online] 2017 [cited 2020 Jun 4];4:226-34. Available from: http://www.roaic.eg.net/text.asp?2017/4/4/226/216454
| Introduction|| |
Maternal hypotension is an undesirable consequence of spinal anesthesia for elective cesarean delivery as it causes detrimental maternal and fetal effects . The incidence of hypotension is more than 80% without any prophylactic measures. A stable hemodynamic status reduces morbidity in the form of distorted consciousness, nausea and vomiting, and fetal acidosis, and improves maternal safety . Although a cochrane study recorded that no single intervention eliminated regional hypotension , many methods to decrease the risk for hypotension have been studied, which include ensuring proper maternal position with uterus displaced off the vena cava, infusion of fluids to increase effective blood volume, physical intervention such as leg wrapping , and prophylactic vasopressors. Ephedrine is the most commonly used among the available vasopressors, especially in our country . Ephedrine is a noncatecholamine sympathomimetic agent that stimulates the α-adrenergic and β-adrenergic receptors by direct and indirect actions . It has been considered the drug of choice for treatment of postspinal hypotension for many years and maintaining uteroplacental blood flow, but it has been shown to cause fetal acidosis , because it crosses the uteroplacental barrier, acts directly on the fetus, and increases its metabolism through β2-adrenergic receptors .
Leg wrapping, aiming at increasing venous return by compressing the lower extremities, is cheap, readily available, applicable everywhere, and simple yet effective means of preventing spinal-induced hypotension in a substantial number of cesarean sections done under spinal anesthesia ,,.
The aim of this randomized controlled trial was to compare the prophylactic effect of an initial ephedrine bolus before low-dose ephedrine infusion and lower limb wrapping for the prevention of maternal hypotension during cesarean section. In addition, we measured umbilical cord blood pH and Apgar scores to evaluate neonatal outcome after these two regimens.
| Patients and methods|| |
After obtaining approval from our Institutional Ethics Committee, a prospective double-blind, randomized, controlled study was conducted in El-Minia University Hospital. A total of 90 nonlaboring singleton parturients, with more than 38 weeks gestation, American Society of Anesthesiology physical status І or ІІ, and scheduled for elective cesarean delivery under spinal anesthesia were enrolled. Their ages ranged from 18 to 40 years, body weights between 55 and 100 kg, and heights between 150 and 180 cm. This study was carried out from November 2015 to June 2016. All patients gave written informed consent.
This study compared the hemodynamic effects of a prophylactic initial bolus dose followed by low-dose infusion of ephedrine or standardized lower extremity compression.
Exclusion criteria were polyhydramnios, fetal abnormalities, hypertension, diabetes, cardiovascular or cerebrovascular disease, anemia or clotting diathesis, contraindication for spinal anesthesia, and a history of hypersensitivity to the drugs used.
All patients received oral premedication with ranitidine 150 mg the night before surgery and on the morning of the surgery. After patients were transferred into the operating room, standard monitoring including heart rate (HR) and noninvasive BP were recorded every 3 min for three times to obtain mean baseline levels with a monitor (Mindray MEC-1000; Mindray iMEC12, Hi-tech industrial Park, Nanshan, Shenzhen, China) attached to the right arm. ECG and pulse oximetry were carried out. Fetal HR was monitored until the time of surgical preparation by external cardiotocography. For all patients intravenous (IV) lines were secured using an 18 G cannula in the left forearm and another 20 G for drug infusion. IV fluid preloading was then carried out with around 15 ml/kg of warmed ringer lactate solution over 15–20 min just before the spinal anesthesia.
A total of 90 women were randomly assigned to one of three treatment groups: group E was treated with an initial ephedrine bolus IV (6 mg) followed by continuous low-dose ephedrine infusion (1.5 mg/min) and sham leg wrapping (bandages wrapped loosely); group L received tight bandaging for lower extremity compression and IV placebo infusion of the study medicine; and group C received the placebo study medicine and sham leg wrapping. The method used was the drawing of sequential sealed envelopes containing numbers previously generated by a computer. Both pregnant women and anesthesiologists who participated in the surgeries were blinded to group allocation.
Study medicine was prepared in an unlabeled 50 ml syringe, containing ephedrine 60 mg ephedrine (2 ml) diluted in volume 40 ml normal saline or placebo (40 ml normal saline), and marked with a randomization number. There were instructions on whether sham or therapeutic wrapping were put into a sealed envelope for each patient. We started the leg compression immediately before the intrathecal block. To maintain blinding of all staff participating in patient care, leg wrapping was performed after visual shielding between the head of the bed and lower extremities was erected. To insure consistent leg compression in all patients, wrapping was carried out by one of three assistants trained to conduct this procedure. In leg patients, elastic bandages (ZOLA, 12 cm×7 m, compression stockings) were applied tightly from toe to midthigh with overlap by one-third between layers.
Spinal anesthesia was induced with the patient in the left lateral position. After skin infiltration with 2% xylocaine, 25 G Quincke’s needle was inserted at L2–3/L3–4 vertebral interspace and 2.0–2.2 ml hyperbaric. Volume of 0.5% bupivacaine (10–12 mg) and fentanyl 15 µg was injected intrathecally. Patients were then immediately turned supine with left lateral tilt. The block height was assessed by using the pinprick test every minute until maximum block height T5 was achieved. Oxygen 3–5 l/min was administered by clear facemask. Systolic blood pressure (SBP) was measured at 2 min intervals, beginning immediately after spinal injection up to 20 min or until delivery and every 5 min up to the end of surgery. The patients received 4 ml bolus of the solution and thereafter infusion started at the rate of 40 ml/h in all patients using a syringe infusion pump (Mindray SK-500II), which corresponded to 1.5 mg of ephedrine in group E. The infusion rate was maintained till the delivery of the baby. Maternal hypotension was defined as SBP less than 80% of baseline values or (SBP) less than 100 mmHg and it was treated with a rescue bolus of IV ephedrine 5 mg and repeated at 2 min intervals if hypotension persisted. Reactive hypertension was characterized as blood pressure (BP) 30% higher than baseline levels so that the study medicine infusion would be stopped for 3 min. HR below 50 bpm was treated with atropine 0.2 mg IV. Nausea and vomiting were assessed. After delivery, five international units of oxytocin were slowly injected as an IV bolus.
The supplementary doses of ephedrine required before delivery and any instances of nausea, vomiting, bradycardia, hypertension, and tachycardia were recorded. A time from skin incision to delivery was recorded.
Apgar scores on the first and fifth minutes of all newborns were determined and a score below eight was considered low. Arterial blood samples were drawn from the umbilical cord immediately after delivery for the determination of blood gases (Cobas b 121; Roche, Mannheim, Germany), and a pH below 7.2 was considered fetal acidosis. Infusion solution was stopped, leg bandages were removed, and sensory and motor block level were reexamined at the end of surgery. The study ended when the patient was transferred to the postoperative care unit.
Previous studies have reported a significant reduction in the incidence of hypotension (from 56 to 17%) by leg wrapping during spinal anesthesia ,,. A sample size of 27 in each group was necessary to detect a difference of this magnitude (39%), with 81% power in a two-tailed test at α=0.05.
Statistical analysis was performed with IBM statistical package for the social sciences version 22 software (SPSS; SPSS Inc., Chicago, Illinois, USA). Ordinal data were expressed as mean±SD. Categorical data were expressed as number and percentage. Independent t-test was used for quantitative data between two groups. Paired t-test was used for quantitative data between two measures within each group. One-way analysis of variance test was used for quantitative data between three groups. The χ2-test was used for percentage data. Wilcoxon’s signed rank was used test for quantitative nonparametric data between two measures within each group. In case of significant group differences in Kruskal–Wallis tests for nonparametric data, the Mann–Whitney U-test was used for subsequent pair-wise comparisons. For all tests, a P-value less than 0.05 was considered statistically significant.
| Results|| |
A total of 90 pregnant women were enrolled into the study. Two patients were excluded from the study, one of them in the ephedrine group and one in the control group, due to insufficient volume of blood sample from the umbilical cord.
Patients’ characteristics including baseline hemodynamic variables and anesthetic surgical parameters were comparable in the three groups ([Table 1]).
As regards SBP, group E showed a significantly lower SBP (P<0.05) than baseline values after spinal block up to 14 min and returned to baseline by 16 min. Leg-wrapped patients and the control group showed a significant decrease in SBP than baseline values all the time.
When comparing the three groups, SBP showed a significant decrease (P<0.05) from 2 min up to 20 min. In control patients, there was a decrease in SBP following spinal injection, which was significantly lower (P<0.05) than that in group E and group L from 2 min up to 20 min. In addition, the SBP was significantly lower (P<0.05) in group L when compared with group E at 6, 8, 10, 12, 14, and 16 min ([Table 2] and [Figure 1]).
The incidence of hypotension was significantly lower in the group C than in groups E and L (P=0.004 and 0.02, respectively) ([Table 3] and [Figure 3]).
Group E had less maximal decrease in SBP (P=0.0001) compared with group C. Comparing group L with groups E and C, there were no significant differences in maximal decrease in SBP ([Table 3]).
As regards the rescue dose of ephedrine, there were significant differences when comparing the three groups (P=0.01), in which there was significant increase in the need for ephedrine in group C than in group E (P=0.02) with no significant differences between group L and both groups E and C ([Table 3]).
The number of episodes of hypotension was significantly higher in group C (52 episodes) compared with group E (28 episodes) and group L (31 episodes) (P=0.04) ([Table 4]).
The HR showed significant difference between the three groups at 2 and 4 min (P=0.002 and 0.03, respectively). Group L showed a significantly lower HR when compared with group E at 2 and 4 min (P=0.002 and 0.02, respectively). HR increased initially and was greater than baseline values in group E at 2, 4, 6, and 8 min, whereas patients of groups L and C had no significant increase when compared with baseline ([Table 5] and [Figure 2]).
As regards bradycardia, there was a significant difference between the three groups (P=0.004). There was a significant difference between group E and both group L and group C (P=0.04 and 0.001, respectively). Nausea and vomiting were not significantly different on comparing the three groups but there was significant increase in the number of patients in group C than in group E (P=0.03) ([Figure 3]). No cases of tachycardia or reactive hypertension were recorded.
|Figure 3 Maternal side effect during delivery (number and percentage of patients). (a) When compared with group E, (b) when compared with group L, (c) when compared with group C. *P<0.05, statistically significant|
Click here to view
The umbilical blood gases were comparable in all the three groups (P>0.05). The mean umbilical artery pH in the three groups was comparable ([Table 6]). Two of the neonates had pH less than 7.20 in group E and no one in either group C or group L had pH less than 7.20. Apgar scores in the first and fifth minute did not show significant differences between the three groups.
| Discussion|| |
Maternal hypotension occurring with intrathecal anesthesia during cesarean section is considered as the most frequent complication. The incidence of hypotension approach 80–100% according to several studies ,. Hypotension can produce serious problems to both the baby and the mother; therefore, several strategies are being used to prevent the incidence of hypotension but there is no optimal technique .
This study demonstrated that an initial bolus dose followed by low-dose infusion of ephedrine is superior to leg wrapping and to placebo treatment for prevention of spinal hypotension during cesarean section. Leg wrapping is associated with less hypotension compared with no intervention.
Prevention of maternal hypotension during delivery
Hypotension occurring during regional anesthesia causes peripheral vasodilatation, which leads to redistribution of central blood, up to 600 ml, to the peripheral compartment. Therefore, many mechanical methods for compressing the lower limbs that augment venous return and suppress redistribution have been used .
A cochrane study concluded that compressing the lower limbs had a moderate effect in preventing hypotension compared with controls . Sharma et al.  demonstrated that the incidence of hypotensive episodes decreased to a significant degree. However, it does not eliminate the incidence of hypotension in spinal anesthesia. Bhagwanjee et al.  observed a significant reduction in incidence of hypotension between leg-wrapped (16.7%) and control groups (83.3%) after spinal block. Similarly Rout et al.  also showed a significant reduction in the incidence of hypotension between rubber Esmarch bandage leg-wrapped (18%) and control (53%) groups after spinal anesthesia. Our study confirmed these findings as the incidence of hypotension was lowest in the leg-wrapped group (46.6%) compared with the control group (86.2%).
Kuhn et al.  compared the effect of leg wrapping and phenylephrine infusion with placebo on SBP during spinal block for cesarean section. They reported that leg wrapping has a limited prophylactic effect on hypotension compared with phenylephrine infusion and the incidence of hypotension was lowest with vasopressor as phenylephrine, compared with the leg-wrapped and control groups. Moreover, there was a less maximal decrease in SAP compared with the control group. These results are in agreement with our results, as the incidence of hypotension was lowest in the group E (37.9% of patients) compared with groups L and C, and there was less maximal decrease in SAP and a lower incidence of hypotension in group E (−9.09±5.5) compared with group C (−21.2±7.2). Therefore, prophylactic use of vasopressor with IV fluid preload was considered the method of choice for prevention of spinal hypotension.
Hemant et al.  reported that combination of preloading and ephedrine is an effective prophylaxis against spinal hypotension and provides hemodynamic stability when compared with the use of ephedrine or preloading alone.
Although ephedrine was considered as the drug of choice as a vasopressor in obstetrics, it not take superiority ,,. It was reported that the administration of ephedrine increases the BP of the mother by its β-adrenergic action, thus preserving uterine and placental blood flow, whereas other vasopressors that have a pure α-agonist were associated with a decrease in this blood flow . However, previous studies observed that ephedrine has a similar efficacy as other vasopressor and causes fetal acidosis . As regards the ephedrine group, this study observed hypotension in 37.9% of cases. Our results were higher than other results reported by Aragão et al.  and Bhardwaj et al. . They compared the efficacy of ephedrine, metaraminol, and phenylephrine in the prevention of hypotension after spinal anesthesia for cesarean section. As for ephedrine, hypotension occurred in 34.5 and 23% of the cases, respectively. These differences were because we used a low dose of ephedrine infusion (1.5 mg/min), whereas they used 2.5 ml/min. On the other hand, Moslemi and Rasooli  used the same infusion rate but hypotension occurred in 65.2% of the cases, which was higher than our results, because we used bolus dose immediately after block whereas they used infusion only. Furthermore, they used a 500 ml crystalloid as preload, whereas we used 15 ml/kg before the spinal anesthesia.
Some previous studies ,, reported a lower incidence of maternal hypotension, nausea, and vomiting when vasopressors were administered by continuous infusion. Therefore, in our study, we used a bolus followed by continuous infusion to maintain good control of SBP with ephedrine, probably to attempt increasing maternal BP before onset of spinal block-induced hypotension. The recommended dose for IV ephedrine infusion is between 0.5 and 5 mg/min . We selected a lower infusion dose (1.5 mg/min) after a small dose bolus (6 mg), as our target was to keep BP at baseline. We found that with this regime ephedrine had a limited effect in maintaining BP without evidence of fetal acidosis as there was a significant decrease in SBP after induction up to 14 min in group E when compared all values with the baseline value but still higher than groups L and C. This result differs from the result of other researchers ,, who used 2.5 ml/min of ephedrine as an infusion after 5 mg bolus dose. They reported that with this dose, ephedrine was effective in maintaining BP without evidence of fetal acidosis.
Umbilical blood gas values and Apgar
Some investigators observed that infusion of the isoproterenol (β-adrenergic agonist) increased oxygen consumption, blood lactate, and glucose concentrations and hence blood pH is decreased . Moreover, there was a relationship between lowering of pH values and ephedrine administration as it crosses the placenta , and causes an acceleration of fetal HR ,. The increase in oxygen consumption was probably related to stimulation of brown fat metabolism, although stimulation of fetal breathing movements may also have contributed . The increase in glucose was considered to be related to β-adrenergic stimulation of hepatic glycogenolysis and the decrease in pH was considered to be caused by anaerobic metabolism resulting from enhanced glucose metabolism in the presence of limited oxygen supply. Ephedrine may also stimulate fetal metabolism by a direct β-adrenergic effect as well as by stimulating endogenous release of fetal catecholamine . Thus, a direct metabolic effect on the fetus is a likely explanation for the acidosis associated with the use of ephedrine.
The incidence of fetal acidosis, which can be assessed through umbilical cord blood gas, especially pH and base excess, is an indicator of neonatal prognosis. Recent meta-analysis reported that acidosis was defined as umbilical arterial blood pH less than 7.20 . In our study, fetal acidosis was observed in only two newborns of group E; however, P-value was not significant. Despite that, there were no clinical consequences in any of them, as all newborn had Apgar scores greater than 8 at the first and fifth minutes and did not require resuscitation or transfer to the ICU. Base excess comparison showed no differences between groups L and C compared with group E. The values were lower in the latter. However, despite the differences, these values are within normal limits.
Previous studies have shown that the use of ephedrine to prevent or treat hypotension associated with spinal and epidural anesthesia for cesarean delivery may not correct fetal acidosis and may even increase it, especially if hypotension still occurs ,,,.
Morgan et al. , who used multiple doses of ephedrine, reported that pH values was low in groups in which infusion rate of ephedrine 3–4 mg/min was used, whereas the groups in which small doses as 1–2 mg/min were used showed no significant difference in pH and base excess when compared with the control group.
Many other investigators have reported lower umbilical pH values after prophylactic maternal ephedrine administration ,,. This was most evident when large ephedrine doses (3–4 mg/min administered IV) were used , and when no crystalloid preload was administered . This result was in agreement with our study as we used a low infusion rate of ephedrine, and thus a small percentage (6.8%) of newborns developed acidosis, whereas no one became acidotic in other groups, with no significant difference between three groups.
Our results differ from the result reported by Ngan Kee et al.  who use a high infusion rate and a larger bolus (10 mg) after the BP fell to less than 90% baseline; they reported 39% incidence of fetal acidosis. This was due to larger initial requirements of ephedrine in first 10 min after induction of spinal anesthesia.
Magalhães et al.  used the value of 7.2 to characterize fetal acidosis; they compared the effect of ephedrine and phenylephrine on the fetus and the mother in elective cesarean sections. In this study, fetal acidosis was observed in only three (10%) newborns of the ephedrine group; however, P-value was not significant between the groups. This result was compatible with our results.
The neonatal outcome in our study similar to that reported in a study by Rout et al. . They divided their patients into three groups: those with legs elevated to 30 degree; or those with elevated and wrapped with elasticated Esmarch bandages; or controls. They found that clinical condition of neonates following delivery in all three groups was good and no fetal acidosis was recorded.
None of the infants in this study had low Apgar score (<8) at the first or fifth minutes. It is known that episodes of hypotension during elective cesarean sections are not a cause of clinically significant fetal changes when treated promptly . A study by Veeser et al. , which included 20 studies with a total of 1069 newborns, reported that only one newborn had Apgar score less than 7 in the fifth minute.
The Apgar scores, assessed at 1 and 5 min, were comparable in all the groups. Current evidence supports that the Apgar score is a better predictor of neonatal outcome than umbilical cord blood gas analysis .
Maternal heart rate during delivery
In this study, we observed that there was significant difference in HR between the groups E and L group at second and forth minutes; this can be because of the effect of bolus dose of ephedrine and slight increase in group C, which is due to normal physiological response of the body to hypotension. This was correlated with the study done by Goudie et al.  who found that HR changes were inconsistent. Some patients had an increase in the HR with the onset of hypotension, whereas others a decrease. This absence of a significant HR increase at the onset of hypotension in their studies could be because of vagal reflexes due to surgical manipulation.
Maternal side effect
There were 31.03% patients in group developed bradycardia as compared with 0% patients in group E, whereas in group L it was 13.3% (P=0.004). This is due to the effect of ephedrine on β1-adrenergic receptor on the heart. Stimulation of these receptors by ephedrine led to increase in pulse rate in group E. This finding was similar to that reported other studies ,, which concluded that the ratio of bradycardia in the control group was significantly higher than that of the ephedrine group.
We found that the incidence of nausea and vomiting was low (13.7%) ingroup E, with significant difference when compared with group C (37.9%) (P=0.03) whereas in group L it was 23.3%, with no significant difference between groups L and E. This difference in result could be attributed to low dose of ephedrine. Our results were in agreement with Bhardwaj et al. , who used a bolus of ephedrine 5 mg followed by infusion 2.5 mg/min to maintain SBP at 100% baseline, and also the incidence of nausea and vomiting was low (11.5%). Furthermore, this finding was similar to the finding of the study performed by Kol et al.  who concluded lower incidence of nausea and vomiting in the ephedrine group as compared with the control group. None of the patients required treatment for nausea and vomiting. In contrast, other authors , observed that ephedrine was associated with maternal symptoms like nausea and vomiting, but they used larger doses of it.
| Conclusion|| |
Ephedrine infusion in a low dose is superior to leg wrapping and to no intervention for preventing spinal hypotension during cesarean section. Administration of small initial bolus ephedrine followed by a low doseinfusion stabilizes arterial BP without clinically significant adverse effects. We assume that prevention of the initial decrease in arterial BP can be further improved by increasing the initial bolus. Leg wrapping prevents hypotension compared with no intervention by venous recruitment from the lower extremities.
Among the weakness of our study design is the failure to record umbilical venous PCO2, which would have enabled us to calculate the A–V difference. In hindsight, we realize this could have added additional interesting data, which might support the idea of increased fetal metabolic rate after ephedrine administration. In addition, there are new alternatives to replace leg wrapping and elevation, which decrease the time consuming but are not available in our hospital.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Wright RG, Shnider SM. Hypotension and regional anaesthesia. In: Shnider SM, Levinson G, editors. Anaesthesia for obstetrics; 3rd edn. Baltimore: Williams and Wilkins; 1993. pp. 397–406.
Saravanan S, Kocarev M, Wilson RC, Watkins E, Columb MO, Lyons G. Equivalent dose of ephedrine and phenylephrine in the prevention of post-spinal hypotension in caesarean section. Br J Anaesth 2006; 96:95–99.
Cyna AM, Andrew M, Emmett RS, Middleton P, Simmons SW. Techniques for preventing hypotension during spinal anaesthesia for caesarean section. Cochrane Database Syst Rev 2006 18:CD002251.
Singh K, Payal YS, Sharma JP, Nautiyal R. Evaluation of hemodynamic changes after leg wrapping in elective cesarean section under spinal anesthesia. J Obstet Anaesth Crit Care 2014; 4:23–28. [Full text]
Halvadia SH, Halvadia HB, Joshi RM, Upadhyaya DP. Hemodynamic effects of simultaneous administration of intravenous ephedrine and spinal anesthesia for cesarean delivery. Natl J Med Res 2012; 2:473–477.
Aragão FF, Aragão PW, Martins CA, Salgado Filhob N, Barroqueiro Ede S. Comparison of metaraminol, phenylephrine and ephedrine in prophylaxis and treatment of hypotension in cesarean section under spinal anesthesia. Rev Bras Anestesiol 2014; 64:299–306.
Lee A, Ngan Kee WD, Gin T. Prophylactic ephedrine prevents hypotension during spinal anesthesia for cesarean delivery but does not improve neonatal outcome: a quantitative systematic review. Can J Anaesth 2002; 49:588–599.
Ralston DH, Shnider SM, DeLorimier AA. Effects of equipotent ephedrine, metaraminol, mephenteramine and methoxamine on uterine blood flow in the pregnant ewe. Anesthesiology 1974; 40:354–370.
Bjørnestad E, Iversen OE, Raeder J. Wrapping of the legs versus phenylephrine for reducing hypotension in parturients having epidural anaesthesia for caesarean section: a prospective, randomized and double-blind study. Eur J Anaesthesiol 2009; 26:842–846.
Ngan Kee WD, Lee A. Multivariate analysis of factors associated with umbilical arterial pH and standard base excess after caesarean section under spinal anaesthesia. Anaesthesia. 2003; 58:125–130.
Morgan PJ, Halpern SH, Tarshis J. The effects of an increase of central blood volume before spinal anesthesia for cesarean delivery: a qualitative systematic review. Anesth Analg 2001; 92:997–1005.
Bhagwanjee S, Rocke DA, Rout CC, Koovarjee RV, Brijball R. Prevention of hypotension following spinal anaesthesia for elective caesarean section by wrapping of the legs. Br J Anaesth 1990; 65:819–822.
Rout CC, Rocke DA, Gouws E. Leg elevation and wrapping in the prevention of hypotension following spinal anaesthesia for elective caesarean section. Anaesthesia 1993; 48:304–308.
Van Bogaert LJ. Prevention of post-spinal hypotension at elective cesarean section by wrapping of the lower limbs. Int J Gynaecol Obstet 1998; 61:233–238.
Adsumelli RSN, Steinberg ES, Schabel JE, Saunders TA, Poppers PJ. Sequential compression device with thigh high sleeves supports MAP during cesarean section under spinal anesthesia. Br J Anaesth 2003; 91:695–698.
Arndt JO, Hock A, Stanton-Hicks M, Stuhmeier KD. Peridural anesthesia and the distribution of blood in supine humans. Anesthesiology 1985; 63:616–623.
Shimosato S, Etsten BE. The role of the venous system in cardiocirculatory dynamics during spinal and epidural anesthesia in man. Anesthesiology 1969; 30:619–628.
Sharma SA, Prasad PN, Marhattha MN, Gupta MP. Prophylactic leg wrapping in elective cesarean section under bupivacaine spinal anesthesia. J Inst Med 2006; 28:13–18.
Kuhn JC, Hauge TH, Rosseland LA, Dahl V, Langesater E. Hemodynamics of phenylephrine infusion versus lower extremity compression during spinal anesthesia for cesarean delivery: a randomized, double-blind, placebo-controlled study. Anesth Analg 2016; 122:1120–1129.
Hemant B, Kiran M, Sudhir KG, Prakash CS. Evaluation of preloading and vasoconstrictors as a combined prophylaxis for hypotension during subarachnoid anaesthesia. Indian J Anaesth 2004; 48:299–303.
Rout CC, Rocke DA, Levin J, Gouws E, Reddy D. A re-evaluation of the role of crystalloid preload in the prevention of hypotension associated with spinal anesthesia for elective cesarean section. Anesthesiology 1993; 79:262–269.
Rout CC, Rocke DA. Prevention of hypotension following spinal anesthesia for cesarean section. Int Anesthesiol Clin 1994; 32:117–135.
Burns SM, Cowan CM, Wilkes RG. Prevention and management of hypotension during spinal anaesthesia for elective caesarean section: a survey of practice. Anaesthesia 2001; 56:794–798.
Simon L, Provenchère S, de Saint Blanquat L, Boulay G, Hamza J. Dose of prophylactic intravenous ephedrine during spinal anesthesia for cesarean section. J Clin Anesth 2001; 13:366–369.
Bhardwaj N, Jain K, Arora S, Bharti N. A comparison of three vasopressor for tight control of maternal blood pressure during cesarean section under spinal anesthesia: effect on maternal and fetal outcome. J Anaesthesiol Clin Pharmacol 2013; 29:26–31.
Moslemi F, Rasooli S. Comparison of prophylactic infusion of phenylephrine with ephedrine for prevention of hypotension in elective cesarean section under spinal anesthesia: a randomized clinical trial. Iran J Med Sci 2015; 40:19–26.
Habbib AS. A review of the impact of phenylephrine administration on maternal hemodynamics and maternal and neonatal outcomes in women undergoing cesarean delivery under spinal anesthesia. Anesth Analg 2012; 114:337–390.
Sia ATH, Tan HS, Sng BL. Closed-loop double-vasopressor automated system to treat hypotension during spinal anaesthesia for caesarean section: a preliminary study. Anaesthesia 2012; 67:1348–1355.
Kansal A, Mohta M, Sethi AK, Tyagi A, Kumar P. Randomised trial of intravenous infusion of ephedrine or mephentermine for management of hypotension during spinal anaesthesia for caesarean section. Anaesthesia 2005; 60:28–34.
Gournay VA, Roman C, Rudolph AM. Effect of beta-adrenergic stimulation on oxygen metabolism in the fetal lamb. Pediatr Res 1999; 45:432–436.
Webb AA, Shipton EA. Re-evaluation of i.m. ephedrine as prophylaxis against hypotension associated with spinal anaesthesia for caesarean section. Can J Anaesth 1998; 45:367–369
Wright RG, Shnider SM, Levinson G, Rolbin SH, Parer JT. The effect of maternal administration of ephedrine on fetal heart rate and variability. Obstet Gynecol 1981; 57:734–738.
Ngan Kee WD, Khaw KS, Lee BB, Lau TK, Gin T. A dose-response study of prophylactic intravenous ephedrine for the prevention of hypotension during spinal anesthesia for cesarean delivery. Anesth Analg 2000; 90:1390–1395.
Jansen AH, Ioffe S, Chernick V. Stimulation of fetal breathing activity by beta-adrenergic mechanisms. J Appl Physiol 1986; 60:1938–1945.
Malin GL, Morris RK, Khan KS. Strength of association between umbilical cord pH and perinatal and long term outcomes: systematic review and meta-analysis. BMJ 2010; 340:1–13.
Shearer VE, Ramin SM, Wallace DH, Dax JS, Gilstrap LC. Fetal effects of prophylactic ephedrine and maternal hypotension during regional anesthesia for cesarean section. J Matern Fetal Med 1996; 5:79–84.
Hughes SC, Ward MG, Levinson G, Shnider SM, Wright RG, Gruenke LD et al.
Placental transfer of ephedrine does not affect neonatal outcome. Anesthesiology 1985; 63:217–219.
Rolbin SH, Cole AFD, Hew EM, Pollard A, Virgint S. Prophylactic intramuscular ephedrine before epidural anaesthesia for caesarean section: efficacy and actions on the fetus and newborn. Can Anaesth Soc J 1982; 29:148–153.
Morgan D, Philip J, Sharma S, Gottumukkala V, Perez B, Wiley J. A neonatal outcome with ephedrine infusions with or without preloading during spinal anesthesia for cesarean section. Anesthesiology 2000; 92:A5.
Rout CC, Rocke DA, Brijball R, Koovarjee RV. Prophylactic intramuscular ephedrine prior to caesarean section. Anaesth Intensive Care 1992; 20:448–452.
Ngan Kee WD, Lau TK, Khaw KS, Lee BB. Comparison of metaraminol and ephedrine infusion for maintaining arterial pressure during spinal anaesthesia for elective cesarean section. Anesthesiology 2001; 95:307–313.
Magalhães E, Govêia CS, Ladeira LCA, Nascimento BG, Kluthcouski MC. Efedrina versus fenilefrina: prevenção de hipotensão arterial durante anestesia raquídea para cesariana e efeitos sobre o feto. Rev Bras Anestesiol 2009; 59:11–20. 19.
Veeser M, Hofmann T, Roth R, Klöhr S, Rossaint R, Heesen M. Vasopressors for the management of hypotension after spinal anesthesia for elective caesarean section. Systematic review and cumulative meta-analysis. Acta Anaesthesiol Scand 2012; 56:810–816.
James FM, Greiss FC, Kemp RA. An evaluation of vasopressor therapy for maternal hypotension during spinal anesthesia. Anesthesiology 1970; 33:25–34.
Goudie TA, Winter AW, Ferguson DJ. Lower limb compression using inflatable splints to prevent hypotension during spinal anaesthesia for caesarean section. Acta Anaesthesiol Scand 1988; 32:541–544.
Kol IO, Kaygusur K, Gursoy S, Cetin A, Kahramangolu Z, Ozkan F, Mimaroglu C. The effects of intravenous ephedrine during spinal anesthesia for cesarean delivery. J Korean Med Sci 2009; 24:883–888.
Bhardwaj N, Jain K, Arora S, Bharti N. A comparison of three vasopressors for tight control of maternal blood pressure during cesarean section under spinal anesthesia: effect on maternal and fetal outcome. J Anaesthesiol Clin Pharmacol 2013; 29:26–31
Cooper DW, Carpenter M, Mowbray P, Desira WR, Ryall DM, Kokri MS. Fetal and maternal effects of phenylepherine and ephedrine during spinal anaesthesia for cesarean delivery. Anesthesiology 2002; 97:1582–1590.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]