[Compression stockings as prevention of hypotension in Cesarean section during spinal anesthesia]. Prevention of hypotension following spinal anaesthesia for elective caesarean section by wrapping of the legs. Prevention of hypotension during spinal anaesthesia for caesarean section: ephedrine infusion versus fluid preload. Ephedrine and phenylephrine for avoiding maternal hypotension due to spinal anaesthesia for caesarean section. Effects on uteroplacental and fetal haemodynamics. Prevention of hypotension during spinal anaesthesia for caesarean section. Leg elevation and wrapping in the prevention of hypotension following spinal anaesthesia for elective caesarean section. The use of thromboembolic deterrent stockings and a sequential compression device to prevent spinal hypotension during caesarean section. Thromboembolic deterrent stockings fail to prevent hypotension associated with spinal anaesthesia for elective caesarean section. Influence of volume preloading on uteroplacental and fetal circulation during spinal anaesthesia for caesarean section in uncomplicated singleton pregnancies.
Inflatable splints and wrapping of the legs have been shown to be effective against hypotension during spinal anaesthesia for Caesarean section. The aim of this study was to investigate if compression stockings could have a similar effect. Thirty healthy mothers scheduled for elective Caesarean section were randomised to have either compression stockings or no stockings on before spinal anaesthesia. The stockings had a pressure effect of 54 mmHg. The women were preloaded with 20 ml isotonic NaCl one hour preoperatively. Hypotension was defined as either a decrease in systolic blood pressure to 80% of preoperative values or systolic blood pressure under 100 mmHg. Blood pressure was measured every second minute, and ephedrine 5 mg was given in the presence of hypotension. Two patients were excluded in the control group. There were no differences in demographic data, extension of blockade, and spinal injection to delivery time. Nine patients in the group with stockings had either no fall in blood pressure or a fall in blood pressure corrected with only 5 mg ephedrine. In the control group the corresponding number was four patients (p < 0.12). Ephedrine dose between zero and 20 minutes and total ephedrine dose was significantly lower in the group with stockings than in the control group (p < 0.038). Five patients in the control group experienced nausea, no patients in the study group had nausea (p < 0.013). In conclusion, compression stockings stabilised the blood pressure during Caesarean section in spinal anaesthesia and led to a significant smaller need for ephedrine. Twenty-four parturients undergoing elective Caesarean section were allocated randomly to have the legs wrapped with elasticated Esmarch bandages immediately following spinal anaesthesia or to serve as controls. Significant hypotension (systolic arterial pressure less than 100 mm Hg and less than 80% of baseline value) was treated with i.v. ephedrine in 5-mg boluses. Leg wrapped patients had a significantly (P = 0.0033) lower incidence (16.7%) of hypotension than controls (83.3%). Only two patients in the leg wrapped group required ephedrine compared with 10 in the control group. Systolic arterial pressure was significantly (P less than 0.05) less in control subjects at 4, 5 and 6 min following spinal injection. No patient in the leg wrapped group became hypotensive following removal of the elasticated bandages. We compared the efficacy of prophylactic ephedrine infusion over fluid preloading in prevention of maternal hypotension during spinal anaesthesia for Caesarean section. Forty-six women undergoing elective Caesarean section at term were allocated randomly to receive either intravenous fluid preloading with Hartmann's solution 20 ml.kg-1 (fluid group) or prophylactic intravenous ephedrine 0.25 mg.kg-1 (ephedrine group). Moderate hypotension was defined as > or = 20% reduction in systolic blood pressure and severe hypotension as > or = 30% reduction in systolic blood pressure. Maternal uterine circulation was measured using Doppler ultrasound in 11 parturients before and after spinal anaesthesia. There was a lower incidence of severe hypotension in the ephedrine group compared with the fluid group (35% vs. 65%, p = 0.04), although the incidence of moderate hypotension was similar. Mean umbilical venous pH was higher in the ephedrine group than in the fluid group (7.33 vs. 7.29, p = 0.02) and the number of patients shivering was lower in the ephedrine group (2 vs. 9, p = 0.02). No difference was found between pre- and postspinal uterine artery pulsatility indices in either group. We conclude that prophylactic ephedrine infusion alone is at least as good as fluid preload alone in combating the hypotension associated with spinal anaesthesia for Caesarean section. The effects of i.v. vasopressors on Doppler velocimetry of the maternal uterine and placental arcuate arteries and the fetal umbilical, renal and middle cerebral arteries were studied during spinal anaesthesia in 19 healthy parturients undergoing elective caesarean section. Fetal myocardial function was investigated at the same time by M-mode echocardiography. The patients were randomized into two groups, to be given either ephedrine or phenylephrine as a prophylactic infusion supplemented with minor boluses if systolic arterial pressure decreased by more than 10 mmHg from the control value. Both the vasopressors restored maternal arterial pressure effectively. The ephedrine group showed no significant differences in any of the Doppler velocimetry recordings relative to the baseline values, but during the phenylephrine infusion the blood flow velocity waveform indices for the uterine and placental arcuate arteries increased significantly and vascular resistance decreased significantly in the fetal renal arteries. Healthy fetuses seem to tolerate these changes in uteroplacental circulation well, however, since the Apgar scores for the newborns and the acid-base values in the umbilical cord were within the normal range in both groups. The results suggest that some caution is required when selecting the specific vasopressor agent, the dosage and the mode of administration for the treatment of maternal hypotension secondary to spinal anaesthesia for caesarean section. Twenty-six parturients scheduled to receive spinal anaesthesia for caesarean section were randomized to receive either isotonic saline 750 ml plus 20 ml/kg (group A) or 750 ml plus 500 ml (group B) before subarachnoid administration of bupivacaine 13 mg. Ephedrine 0.15 mg/kg i.v. followed by an infusion 0.4 mg.kg(-1) h(-1) were then administered in group B. In both groups ephedrine 10 mg/min i.v. was given if the mean arterial blood pressure decreased more than 10 mmHg. Despite the fluid preload and large doses of ephedrine noted {median (range), group A 30 mg (10-80), group B 92 mg (25-194)}, hypotension, sometimes accompanied by nausea, still occurred. Mean maternal arterial was significantly lower in group A than in group B 5-10 min after induction of spinal anaesthesia (P < 0.05). There was no difference in the frequency of nausea or vomiting, Apgar score, or pH in umbilical cord blood. One neonate in group A and 2 in group B were acidotic. In conclusion, a reduced volume loading could be compensated with an increased ephedrine administration after induction of spinal anaesthesia, without increasing the incidence of hypotension or other maternal or neonatal complications. However, the fluid volumes and/or ephedrine doses used were not sufficient to prevent hypotension altogether. Ninety-seven parturients undergoing elective Caesarean section were allocated randomly to have their legs elevated to approximately 30 degrees on pillows or elevated and wrapped with elasticated Esmarch bandages or neither (controls) following spinal anaesthesia. All patients received intravenous crystalloid (20 ml.kg-1 over 20 min) prior to spinal injection and were placed in the left lateral tilt position. Significant hypotension was treated with intravenous ephedrine in 5 mg bolus doses. Leg wrapping resulted in a significant reduction in the incidence of postspinal hypotension in comparison to the control group (18% compared to 53%, p = 0.004). This represents a five-fold reduction in the likelihood of postspinal hypotension (odds ratio 5.3, 95% CI 1.7-16.3). Leg elevation alone did not significantly reduce the incidence of hypotension (39%). There was no significant difference in the time of onset of hypotension between the groups. For those patients requiring ephedrine, there was no significant difference in mean dose requirements between the groups. The use of leg compression immediately postspinal provides a simple means of reducing the accompanying hypotension and should be used more widely. Hypotension is a common side effect of spinal anaesthesia for caesarean section. We have performed a randomised, controlled study to determine the efficacy of a sequential compression device (SCD) (Kendall) in combination with thromboembolic deterrent (TED) stockings (Kendall) to reduce the incidence of hypotension in this setting. Within 20 min of spinal injection, there was no statistically significant difference in the incidence of hypotension (defined as less than 100 mmHg and less than 80% of baseline blood pressure) (TED/SCD group 65%, control 80%, P = 0.12). However, there was a trend for those receiving TED/SCD prophylaxis to require less ephedrine to maintain normotension than the control group (median TED/SCD 3 mg, control 6 mg, P = 0.08). The administration of ephedrine deviated from protocol on a total of 46 occasions (2.3% of recordings). To try to reduce the influence of this, we reinspected our data using time to first episode of hypotension with a Kaplan-Meier survival analysis. This showed that the instantaneous risk (hazard) of developing hypotension was 1.8 (95% CI: 1.1-2.9) times higher in controls than those receiving TED/SCD prophylaxis (P = 0.02). Despite demonstrating some benefit of TED/SCD prophylaxis to prevent hypotension, we do not consider that the magnitude of this benefit warrants their routine use. This study was carried out to determine whether the use of thrombo-embolic deterrent (TED) stockings, in combination with an intravenous crystalloid preload, would prevent hypotension following spinal anaesthesia for caesarean section. Fifty parturients undergoing elective caesarean section under spinal anaesthesia were randomly allocated into two groups. TED stockings were applied to the study group 1 h before spinal anaesthesia but none were applied to the control group. Both groups received a crystalloid preload of 15 ml kg(-1) over 15 min before spinal injection. Significant hypotension, defined as an absolute value of systolic arterial pressure (SAP) of less than 90 mmHg and a decrease of more than 20% from baseline SAP was treated with 3 mg bolus of ephedrine as required. The difference in SAO between the two groups was not statistically significant. In the control group, 80% of parturients required ephedrine as opposed to 56% in the TED group; a difference that was also not statistically significant. Effects of volume preloading during spinal anaesthesia for elective caesarean section on maternal blood pressure, feto-maternal circulation and fetal outcome.
                In a pilot study a randomised trial was performed in 22 healthy women with uncomplicated, singleton pregnancies at 36-40 weeks of gestation undergoing elective caesarean section under spinal anaesthesia. In the low volume group (group A) patients received 150 ml of crystalloid solution for preloading, in the high volume group (group B) they were given 15 ml/kg of crystalloid solution for preloading before the initiation of spinal anaesthesia. Maternal blood pressure was monitored intermittently. Hypotension was defined as a decrease in systolic pressure to less than 80% of the baseline value. The Doppler flow evaluation consisted of measurements from the uterine artery at the placental site, fetal umbilical artery and fetal middle cerebral artery. Pulsatility indices were derived before and after fluid preloading, and when spinal anaesthesia was established. The neonatal outcome was assessed by Apgar scores, arterial acid base status and neurologic and adaptive capacity scores (NACS).
                The incidence of maternal hypotension in both groups was 45.5% (n = 10); 3 cases occurred in group A compared to 7 cases in group B (n.s.). There was no evidence that the high dose volume is useful in preventing maternal hypotension. The pulsatility indices of uterine arteries, umbilical arteries and middle cerebral arteries were not altered. Statistical analysis showed no changes in neonatal outcome concerning umbilical arterial pH, Apgar score and NACS (n.s.) between groups A and B.
                Our preliminary results suggest that high dose crystalloid volume preloading has no preventive function in the avoidance of maternal hypotension in healthy parturients undergoing elective caesarean section under spinal anaesthesia, and shows no harmful effects on neonatal outcome as long as maternal hypotension is corrected immediately. However, the statistical significance may reflect the small sample size, and larger series are needed before changing the current management.
                Copyright 2002 S. Karger AG, Basel
While interventions such as colloids, ephedrine, phenylephrine or lower leg compression can reduce the incidence of hypotension, none have been shown to eliminate the need to treat maternal hypotension during spinal anaesthesia for caesarean section. No conclusions can be drawn regarding rare adverse effects due to the relatively small numbers of women studied.
[Note: The 89 citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]