Techniques for preventing hypotension during spinal anaesthesia for caesarean section

Effects of neuraxial anesthesia in sitting and lateral positions on maternal hemodynamics in cesarean section: A systematic review and meta-analysis

STUDY OBJECTIVE

During cesarean section, hypotension is a frequent side effect of spinal anesthesia. As a sitting or lateral position is required for spinal anesthesia performance, which of these two positions is more likely to cause intraoperative nausea, vomiting, and hypotension is still unknown. This meta-analysis compared the effects of these two positions on maternal hemodynamics and intraoperative nausea and vomiting.

DESIGN

Systematic review and meta-analysis.

SETTING

Operating room.

PATIENTS

This study included 803 patients from 12 randomized controlled trials (RCTs).

INTERVENTIONS

Neuraxial anesthesia in sitting position vs. lateral position.

MEASUREMENTS

We chose RCTs comparing the effects of spinal anesthesia in the sitting and lateral positions on maternal hemodynamics by thoroughly searching PubMed, Embase, the Cochrane Library, and the Web of Science for articles published from database inception until October 31, 2022. The Cochrane Handbook was used to assess the methodological quality of each RCT; the results were analyzed using RevMan 5.4 software; and the Egger test was used to assess publication bias.

MAIN RESULTS

12 randomised controlled trials with 803 participants were ultimately included in the final analysis. No significant differences were observed between the two positions in terms of the incidence of hypotension(RR, 0.82; 95% CI, 0.58-1.16; P = 0.26; I2 = 66%), lowest systolic blood pressure(MD, -0.81; 95% CI, -7.38-5.75; P = 0.81; I2 = 86%), the dose of ephedrine(MD, -1.19; 95% CI, -4.91-2.52; P = 0.53; I2 = 83%), and number of parturients requiring ephedrine(RR, 0.97; 95% CI, 0.64-1.46; P = 0.88; I2 = 74%). For the incidence of intraoperative nausea and vomiting, there was no statistical difference between the two positions.

CONCLUSION

Parturients undergoing elective cesarean section under spinal anesthesia in the sitting or lateral position experienced similar incidence of hypotension, and there were no significant differences between these two positions in terms of the amount of ephedrine administered or the number of patients needing ephedrine. In both positions, the frequency of nausea and vomiting was comparable. The ideal position for anesthesia can be chosen based on the preferences and individual circumstances of the parturient and anesthesiologist.

Non-Invasive Monitoring during Caesarean Delivery: Prevalence of Hypotension and Impact on the Newborn

BACKGROUND

The aim of our study was to investigate the prevalence of perioperative hypotension after spinal anesthesia for cesarean section using non-invasive continuous hemodynamic monitoring and its correlation with neonatal well-being.

METHODS

We included 145 patients. Spinal anesthesia was performed with a combination of hyperbaric bupivacaine 0.5% (according to a weight/height scheme) and fentanyl 20 μg. Hypotension was defined as a mean arterial pressure (MAP) < 65 mmHg or <60 mmHg. We also evaluated the impact of hypotension on neonatal well-being.

RESULTS

Perioperative maternal hypotension occurred in 54.5% of cases considering a MAP < 65 mmHg and in 42.1% with the more conservative cut-off (<60 mmHg). Severe neonatal acidosis occurred in 1.4% of neonates, while an Apgar score ≥ 9 was observed in 95.9% at 1 min and 100% at 5 min.

CONCLUSIONS

Continuous non-invasive hemodynamic monitoring allowed an early detection of maternal hypotension leading to a prompt treatment with satisfactory results considering neonatal well-being.

Consensus on the Southeast Asian management of hypotension using vasopressors and adjunct modalities during cesarean section under spinal anesthesia

BACKGROUND AND AIMS

This consensus statement presents a comprehensive and evidence-based set of guidelines that modify the general European or US guidelines for hypotension management with vasopressors during cesarean delivery. It is tailored to the Southeast Asian context in terms of local human and medical resources, health system capacity, and local values and preferences.

METHODS AND RESULTS

These guidelines were prepared using a methodological approach. Two principal sources were used to obtain the evidence: scientific evidence and opinion-based evidence. A team of five anesthesia experts from Vietnam, the Philippines, and Thailand came together to define relevant clinical questions; search for literature-based evidence using the MEDLINE, Scopus, Google Scholar, and Cochrane libraries; evaluate existing guidelines; and contextualize recommendations for the Southeast Asian region. Furthermore, a survey was developed and distributed among 183 practitioners in the captioned countries to gather representative opinions of the medical community and identify best practices for the management of hypotension with vasopressors during cesarean section under spinal anesthesia.

CONCLUSIONS

This consensus statement advocates proactive management of maternal hypotension during cesarean section after spinal anesthesia, which can be detrimental for both the mother and fetus, supports the choice of phenylephrine as a first-line vasopressor and offers a perspective on the use of prefilled syringes in the Southeast Asian region, where factors such as healthcare features, availability, patient safety, and cost should be considered.

Accuracy and trending ability of finger plethysmographic cardiac output monitoring in late pregnancy

PURPOSE

Individuals in late pregnancy are at risk of significant hemodynamic variations, especially during Cesarean delivery. Although non-invasive monitoring might enable the early detection of variations in cardiac output (CO), clinical validation is lacking.

METHODS

In a prospective, single-center study, we measured CO simultaneously with finger plethysmography and transthoracic echocardiography in 100 third-trimester pregnant individuals in the supine and left lateral decubitus (LLD) positions.

RESULTS

A Bland-Altman analysis revealed a mean (standard deviation) bias of 1.36 (1.04) L·min-1 in the supine position (95% limits of agreement, -0.68 to 3.4 L·min-1; percent error, 26.6%), indicating overestimation by finger plethysmography. The intra-class correlation coefficient was 0.43 (95% confidence interval [CI], 0.33 to 0.51). Regarding the changes in CO induced by the supine-to-LLD transition, the concordance rate in a four-quadrant plot was 98.3% (95% CI, 91.1 to 99.9%).

CONCLUSION

Our study showed a poor reliability of finger plethysmography for static measurement of CO. Nevertheless, finger plethysmography had a reasonably high concordance rate for the detection of CO changes secondary to positional changes in late-pregnant individuals. STUDY REGISTRATION DATE: www.

CLINICALTRIALS

gov (NCT03735043); registered 8 November 2018.

Peripheral Perfusion Index: A Predictor of Post-Spinal Hypotension in Caesarean Section

Background

Early prediction of hypotension helps to decide appropriate prophylactic measures and, hence, safe anaesthesia for mothers and improved neonatal outcomes. Perfusion index (PI) measured from a standard pulse oximeter has shown positive results in the prediction of hypotension. This study aims to determine if PI can equally predict hypotension in parturients after administration of spinal anaesthesia at different time points.

Methods

Parturients posted for elective caesarean section belonging to the American Society of Anesthesiology II (ASA II) were divided into two groups based on baseline PI as group A <3.5 and group B ≥3.5. Fifty-six parturients were enrolled in the study. PI and blood pressure were monitored at baseline, every two minutes for 12 minutes and every five minutes until the end of the surgery, after administration of spinal anaesthesia with hyperbaric bupivacaine 10 mg. Incidence of hypotension was compared between groups at all time points of observation. Spearman’s rank correlation coefficient was determined to check the correlation between baseline PI and the number of episodes of hypotension. Receiver operating characteristic (ROC) curve was plotted to determine the ideal cut-off at different time points.

Results

Baseline PI significantly correlated with the number of episodes of hypotension (r-0.525). The overall incidence of hypotension was significantly higher in parturients with baseline PI ≥3.5 (79.16%) as compared to those with PI <3.5 (33.33%). The incidence of hypotension at sixth, 10th and 37th minutes post-spinal anaesthesia administration was significantly higher in the group with PI ≥3.5. The sensitivity and specificity for the 3.5 cut-off of PI were 85.7% and 60%, respectively, at the 6th and 10th minute after spinal administration. A higher cut-off of 3.9 increases the specificity to 69% without much change in the sensitivity.

Conclusion 

Parturients with PI >3.9 at baseline have a higher risk of hypotension in the initial 10-12 minutes following spinal anaesthesia during caesarean delivery.

Effect of maternal positioning during cardiopulmonary resuscitation: a systematic review and meta-analyses

Background

Although rare, cardiac arrest during pregnancy is the leading cause of maternal death. Recently, its incidence has been increasing worldwide because more pregnant women have risk factors. The provision of early, high-quality cardiopulmonary resuscitation (CPR) plays a major role in the increased likelihood of survival; therefore, it is important for clinicians to know how to manage it. Due to the aortocaval compression caused by the gravid uterus, clinical guidelines often emphasise the importance of maternal positioning during CPR, but there has been little evidence regarding which position is most effective.

Methods

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, and OpenGrey (updated on April 3, 2021). We included clinical trials and observational studies with reported outcomes related to successful resuscitations.

Results

We included eight studies from the 1,490 screened. The eight studies were simulation-based, crossover trials that examine the quality of chest compressions. No data were available about the survival rates of mothers or foetuses/neonates. The meta-analyses showed that resuscitation of pregnant women in the 27°–30° left-lateral tilt position resulted in lower quality chest compressions. The difference is an 19% and 9% reduction in correct compression depth rate and correct hand position rate, respectively, compared with resuscitations in the supine position. Inexperienced clinicians find it difficult to perform chest compressions in the left-lateral tilt position.

Conclusions

Given that manual left uterine displacement allows the patient to remain supine, the resuscitation of women in the supine position using manual left uterine displacement should continue to be supported. Further research is needed to fill knowledge gaps regarding the effects of maternal positioning on clinical outcomes, such as survival rates following maternal cardiac arrest.

Comparison of sequential versus pre mixed administration of intrathecal fentanyl with hyperbaric bupivacaine for patients undergoing elective Caesarean section at Zewditu memorial referral hospital: A prospective cohort study

Background

Spinal anesthesia (SA) is the method of choice for surgery below umbilicus like elective cesarean section. However, Spinal anesthesia is associated with hypotension and limited analgesia duration. To minimize those complications adding opioids like fentanyl either sequentially with separate syringe or pre mixed with local anesthetics become common practice.

Objective

To compare the hemodynamic and analgesic effect of sequential versus pre mixed injection of intrathecal fentanyl with hyperbaric bupivacaine for patients who underwent elective CS under Spinal anesthesia.

Method

A prospective cohort study was performed on parturient who undergone elective cesarean section from 01 January 2020 to 30 March 2020. The decision to give either sequential or premixed drug was based on the responsible anesthetists. Sixty-six American society of Anesthesiologist Ⅱ age ≥18 was recruited. Those who received sequentially were grouped as (S- group) and those who had received pre mixed technique were grouped as (M-group). Data were entered into Epi Info version 7.0 and transported into SPSS Version 22 for analysis. Based on normality assumption, analysis was done by independent t-test for normally distributed data. Whereas Mann –Whitney U test for non-normally distributed data and x2 (Chi-square) test for categorical variable. P-value <0.05 was considered as statistically significant.

Result

Significant reduction in intra operative mean arterial blood pressure was seen in premixed group compared to Sequential group until 15th minute immediately after spinal anesthesia. Thus, the incidence of hypotension was higher in M − group compared to S- group, (p < 0.05). The median Postoperative pain VAS score was significantly lower in the S - group compared to M − group of 4th, 5th and 6th hr. The mean time for 1st rescue analgesic request time was prolonged in the S - group compared to M − group (287.909 ± 15.255 vs. 261.39 ± 25.378) min respectively (p < 0.001).

Conclusion

The Sequential intrathecal injection of fentanyl and hyperbaric bupivacaine provided significant improvement in the blood pressure stability and of sensory and motor block compared to premixed groups.

•

Spinal anesthesia is associated with hypotension and limited analgesia duration.

•

To minimize those complications adding opioids like fentanyl either pre mixed with local anesthetics or in separate syringe become common practice.

•

Sequential intrathecal injection of fentanyl and hyperbaric bupivacaine provided significant improvement in the blood pressure stability and of sensory and motor block compared to premixed groups.

•

Longer time to first analgesia request was seen in sequential group compared with premixing group.

•

There was significant lower total tramadol consumption in sequential compared with premixing group but comparable total diclofenac consumption.

Blood pressure and cardiac output during caesarean delivery under spinal anaesthesia: a prospective cohort study

OBJECTIVES

We have previously established a method to measure transfer of nutrients between mother, placenta and fetus in vivo. The method includes measurements of maternal and fetal blood flow by Doppler ultrasound prior to spinal anaesthesia. Spinal anaesthesia affects maternal blood pressure and cardiac output. We aimed to determine the effect of spinal anaesthesia in mothers undergoing an elective caesarean section on blood pressure, heart rate and cardiac output, and whether cardiac output levels were comparable before induction of spinal anaesthesia and before delivery.

DESIGN

Prospective cohort study.

SETTING

Tertiary hospital in Norway.

PARTICIPANTS

76 healthy women with uneventful pregnancies undergoing an elective caesarean section.

INTERVENTIONS

We induced spinal anaesthesia with a standard prevention of hypotension including intravenous fluid coloading and phenylephrine infusion.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measure was maternal cardiac output, and secondary outcome measures were invasive systolic blood pressure and heart rate. We measured heart rate and blood pressure by continuous invasive monitoring with a cannula in the radial artery. Cardiac output was estimated based on continuous arterial waveform. We compared maternal parameters 30 s before induction of spinal anaesthesia to 30 s before delivery.

RESULTS

Median age at delivery was 34.5 (range 21-43) years and 17 of 76 women were nulliparous. The most prevalent indications were previous caesarean section and maternal request. Among 76 included women, 71 had sufficient data for analysis of endpoints. Median cardiac output was 6.51 (IQR (5.56-7.54) L/min before spinal anaesthesia and 6.40 (5.83-7.56) L/min before delivery (p=0.40)). Median invasive systolic blood pressure increased from 128.5 (120.1-142.7) mm Hg to 134.1 (124.0-146.6) mm Hg (p=0.014), and mean heart rate decreased from 86.0 (SD 13.9) to 75.2 (14.2) (p<0.001).

CONCLUSIONS

Maternal cardiac output at the time of caesarean delivery is comparable to levels before induction of spinal anaesthesia.

TRIAL REGISTRATION NUMBER

NCT00977769.

Associated factors with umbilical arterial pH after cesarean delivery under spinal anesthesia: a retrospective cohort study

BACKGROUND

Maximum decrease of blood pressure and number of minutes of hypotension were independently associated with umbilical arterial pH. However, the impact of hypotension considering the duration of it on umbilical arterial pH is unknown.

METHODS

Pregnant women aged ≥ 20 years who delivered a baby at full-term via a cesarean delivery under a single-shot spinal anesthesia between January 2017 and March 2019 were included. The main outcome was to predict umbilical arterial pH, based on the value of the time integral of hypotension. Patient demographics, patient comorbidities, and intraoperative data, including the total dose of ephedrine and phenylephrine by fetal delivery and cumulative duration of maternal hypotension, were evaluated. Maternal hypotension was reflected as a decrease in systolic arterial pressure and mean arterial pressure to < 80% of baseline values. The systolic arterial pressure and mean arterial pressure were independently included in a multiple regression analysis along with all other explanatory factors to predict the umbilical arterial pH.

RESULTS

Of the 416 eligible patients, 381 were enrolled. When including the systolic arterial pressure or mean arterial pressure in the model, emergency cases, the total dose of ephedrine, hypertensive disorders of pregnancy, and systolic arterial pressure or mean arterial pressure values were found to be significant predictive factors of umbilical arterial pH.

CONCLUSION

Our results suggest that an elevated time integral of maternal hypotension may have a negative impact on umbilical arterial pH. Therefore, to minimize the risk of fetal acidosis, maternal hypotension should be prevented with the consideration of vasopressors selection.

[Hypotension induced by spinal anesthesia during cesarean section : Current treatment concepts]

Arterial hypotension during cesarean delivery under spinal anesthesia can cause maternal and fetal adverse effects. Therefore, current guidelines recommend the continuous and preferably prophylactic use of vasopressors, emphasizing the use of alpha-agonists, such as phenylephrine. Besides a left lateral uterine displacement either an intravenous colloid preloading or a crystalloid co-loading is recommended. The blood pressure goal is to maintain a systolic arterial blood pressure of at least 90% of the initial baseline value and to avoid a drop to less than 80% of this baseline. To achieve this goal a prophylactic continuous phenylephrine infusion with an adjustable flow rate is recommended. It is advised to start with an initial dose of 25-50 µg/min, initiated immediately following the intrathecal injection of the local anesthetic and titrated according to the vital parameters. Parturients with cardiac diseases should be preoperatively evaluated following individual hemodynamic goals.

Intravenous norepinephrine and mephentermine for maintenance of blood pressure during spinal anaesthesia for caesarean section: An interventional double-blinded randomised trial

Background and Aims:

Spinal anaesthesia induced hypotension (SAIH) and bradycardia may prove deleterious to both parturient and baby, hence vasopressors play a vital role in their management. Recent studies on norepinephrine as rescue vasopressor during subarachnoid block (SAB) enlighten its role for SAIH. This randomised double-blind trial was conducted to compare the effect of intermittent intravenous boluses of norepinephrine and frequently used mephentermine for management of SAIH in caesarean section (CS) to prove whether norepinephrine produces comparable effects or superior to mephentermine.

Methods:

After approval from Institutional Ethics Committee and registration in Clinical Trials Registry India (CTRI/2019/06/019652), 256 parturients posted for elective CS under SAB were randomly allocated into Group-N and Group-M (n = 84) using chit system, who received boluses of intravenous norepinephrine 8μg and mephentermine 6mg for SAIH, respectively. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), Response%, Apgar score and maternal complications were analysed.

Results:

The changes in SBP and DBP were comparable in both the groups. It was significantly low after SAB compared to baseline and significantly high compared to 1^st hypotensive value in both the groups throughout the study period (<0.0001). HR was comparable for initial 10 min, thereafter it was significantly high in Group-M (<0.0001) till 40 min. Response% after the first bolus was significantly high in Group-N (59.30n ± 29.21 vs 39.78 ± 25.6; P = <0.0001).

Conclusion:

Intravenous norepinephrine is better than mephentermine with respect to high response% and stable maternal HR although both are equally effective in maintaining blood pressure following SAIH during elective CS.

Effectiveness of Leg Elevation to Prevent Spinal Anesthesia-Induced Hypotension during Cesarean Delivery in the Resource-Limited Area: Open Randomized Controlled Trial

Background

Postspinal hypotension is the most common complication after spinal anesthesia for cesarean section (CS). Hypotension mainly occurs due to the reductions of vascular tone leading to decreased systemic vascular resistance and decreased venous return. The aim of this study was to assess the effectiveness of leg elevation (LE) as a method of prevention of postspinal hypotension in patients who undergo cesarean section under spinal anesthesia.

Methods

This is a single-center parallel-randomized controlled trial study, and 52 full-term parturients scheduled for elective cesarean section who meets inclusion criteria were included in the study. The randomization sequence was created by a researcher not participating in patient management using a computer random generator. The participant was randomly assigned to the leg elevation group (n = 26) or to the control group (n = 26) of usual perioperative care.

Results

The proportions of patients who develop hypotension are lower (8 (33.3%)) in the leg elevation group than the control group (15 (62.5%)) with an X ² (1, N = 48) = 4.09, P=0.043. The relative risk of developing postspinal hypotension in the leg elevation group compared to the control group was 0.47 (95% CI, 0.28-1.00). The proportion of severe hypotension was significantly decreased in the leg elevation group at a P value of 0.02.

Conclusion

Performing leg elevation immediately after spinal anesthesia reduced the incidence of hypotension. The trial is registered with PACTR201908713181850.

The effect of baricity of intrathecal bupivacaine for elective cesarean delivery on maternal cardiac output: a randomized study

BACKGROUND

Hemodynamic instability during spinal anesthesia for cesarean delivery is associated with adverse maternal and fetal outcomes. Plain and hyperbaric bupivacaine are commonly used for cesarean delivery, however, their distinctive pharmacologic properties may affect maternal hemodynamic profiles differently. The aim of this study was to compare hemodynamic profiles using a suprasternal Doppler cardiac output (CO) monitor in healthy term parturients randomized to receive plain or hyperbaric bupivacaine for cesarean delivery.

METHODS

One hundred-and-sixty-eight healthy parturients scheduled for elective cesarean delivery were randomly assigned to receive 10.9 mg of intrathecal 0.5% plain or hyperbaric bupivacaine, both with 0.2 mg morphine. The primary outcome was CO change after spinal anesthesia. Secondary outcomes were the incidence of hypotension, vasopressor use, and conversion to general anesthesia.

RESULTS

The mean (±SD) CO at baseline, 1 min and 5 min after spinal anesthesia, and after placental delivery was 4.6 ± 1.2, 5.4 ± 1.3, 5.1 ± 1.4, and 6.4 ± 1.7 L/min in the plain bupivacaine, and 4.5 ± 1.1, 5.2 ± 1.3, 4.9 ± 1.3, and 6.2 ± 1.9 L/min in the hyperbaric bupivacaine group. There were no significant differences in CO, mean arterial pressure, or systemic vascular resistance. Incidences of hypotension, vasopressor and supplemental analgesic use, and conversion to general anesthesia, were not different between groups.

CONCLUSIONS

Cardiac output changes after plain or hyperbaric bupivacaine were not different in term parturients undergoing spinal anesthesia for cesarean delivery. Further studies comparing block quality and the rate of conversion to general anesthesia are required.

Techniques for preventing hypotension during spinal anaesthesia for caesarean section

BACKGROUND

Maternal hypotension is the most frequent complication of spinal anaesthesia for caesarean section. It can be associated with nausea or vomiting and may pose serious risks to the mother (unconsciousness, pulmonary aspiration) and baby (hypoxia, acidosis, neurological injury).

OBJECTIVES

To assess the effects of prophylactic interventions for hypotension following spinal anaesthesia for caesarean section.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (9 August 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials, including full texts and abstracts, comparing interventions to prevent hypotension with placebo or alternative treatment in women having spinal anaesthesia for caesarean section. We excluded studies if hypotension was not an outcome measure.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted data from eligible studies. We report 'Summary of findings' tables using GRADE.

MAIN RESULTS

We included 125 studies involving 9469 women. Interventions were to prevent maternal hypotension following spinal anaesthesia only, and we excluded any interventions considered active treatment. All the included studies reported the review's primary outcome. Across 49 comparisons, we identified three intervention groups: intravenous fluids, pharmacological interventions, and physical interventions. Authors reported no serious adverse effects with any of the interventions investigated. Most trials reported hypotension requiring intervention and Apgar score of less than 8 at five minutes as the only outcomes. None of the trials included in the comparisons we describe reported admission to neonatal intensive care unit. Crystalloid versus control (no fluids) Fewer women experienced hypotension in the crystalloid group compared with no fluids (average risk ratio (RR) 0.84, 95% confidence interval (CI) 0.72 to 0.98; 370 women; 5 studies; low-quality evidence). There was no clear difference between groups in numbers of women with nausea and vomiting (average RR 0.19, 95% CI 0.01 to 3.91; 1 study; 69 women; very low-quality evidence). No baby had an Apgar score of less than 8 at five minutes in either group (60 babies, low-quality evidence). Colloid versus crystalloid Fewer women experienced hypotension in the colloid group compared with the crystalloid group (average RR 0.69, 95% CI 0.58 to 0.81; 2009 women; 27 studies; very low-quality evidence). There were no clear differences between groups for maternal hypertension requiring intervention (average RR 0.64, 95% CI 0.09 to 4.46, 3 studies, 327 women; very low-quality evidence), maternal bradycardia requiring intervention (average RR 0.98, 95% CI 0.54 to 1.78, 5 studies, 413 women; very low-quality evidence), nausea and/or vomiting (average RR 0.89, 95% CI 0.66 to 1.19, 14 studies, 1058 women, I² = 29%; very low-quality evidence), neonatal acidosis (average RR 0.83, 95% CI 0.15 to 4.52, 6 studies, 678 babies; very low-quality evidence), or Apgar score of less than 8 at five minutes (average RR 0.24, 95% CI 0.03 to 2.05, 10 studies, 730 babies; very low-quality evidence). Ephedrine versus phenylephrine There were no clear differences between ephedrine and phenylephrine groups for preventing maternal hypotension (average RR 0.92, 95% CI 0.71 to 1.18; 401 women; 8 studies; very low-quality evidence) or hypertension (average RR 1.72, 95% CI 0.71 to 4.16, 2 studies, 118 women, low-quality evidence). Rates of bradycardia were lower in the ephedrine group (average RR 0.37, 95% CI 0.21 to 0.64, 5 studies, 304 women, low-quality evidence). There was no clear difference in the number of women with nausea and/or vomiting (average RR 0.76, 95% CI 0.39 to 1.49, 4 studies, 204 women, I² = 37%, very low-quality evidence), or babies with neonatal acidosis (average RR 0.89, 95% CI 0.07 to 12.00, 3 studies, 175 babies, low-quality evidence). No baby had an Apgar score of less than 8 at five minutes in either group (321 babies; low-quality evidence). Ondansetron versus control Ondansetron administration was more effective than control (placebo saline) for preventing hypotension requiring treatment (average RR 0.67, 95% CI 0.54 to 0.83; 740 women, 8 studies, low-quality evidence), bradycardia requiring treatment (average RR 0.49, 95% CI 0.28 to 0.87; 740 women, 8 studies, low-quality evidence), and nausea and/or vomiting (average RR 0.35, 95% CI 0.24 to 0.51; 653 women, 7 studies, low-quality evidence). There was no clear difference between the groups in rates of neonatal acidosis (average RR 0.48, 95% CI 0.05 to 5.09; 134 babies; 2 studies, low-quality evidence) or Apgar scores of less than 8 at five minutes (284 babies, low-quality evidence). Lower limb compression versus control Lower limb compression was more effective than control for preventing hypotension (average RR 0.61, 95% CI 0.47 to 0.78, 11 studies, 705 women, I² = 65%, very low-quality evidence). There was no clear difference between the groups in rates of bradycardia (RR 0.63, 95% CI 0.11 to 3.56, 1 study, 74 women, very low-quality evidence) or nausea and/or vomiting (average RR 0.42, 95% CI 0.14 to 1.27, 4 studies, 276 women, I² = 32%, very-low quality evidence). No baby had an Apgar score of less than 8 at five minutes in either group (130 babies, very low-quality evidence). Walking versus lying There was no clear difference between the groups for women with hypotension requiring treatment (RR 0.71, 95% CI 0.41 to 1.21, 1 study, 37 women, very low-quality evidence). Many included studies reported little to no information that would allow an assessment of their risk of bias, limiting our ability to draw meaningful conclusions. GRADE assessments of the quality of evidence ranged from very low to low. We downgraded evidence for limitations in study design, imprecision, and indirectness; most studies assessed only women scheduled for elective caesarean sections. External validity also needs consideration. Readers should question the use of colloids in this context given the serious potential side effects such as allergy and renal failure associated with their administration.

AUTHORS' CONCLUSIONS

While interventions such as crystalloids, colloids, ephedrine, phenylephrine, ondansetron, or lower leg compression can reduce the incidence of hypotension, none have been shown to eliminate the need to treat maternal hypotension in some women. We cannot draw any conclusions regarding rare adverse effects associated with use of the interventions (for example colloids) due to the relatively small numbers of women studied.

Thoracic ultrasound evaluation and B-type natriuretic peptide value in elective cesarean section under spinal anesthesia

Background

Pregnancy-induced changes in cardiovascular status make women more susceptible to pulmonary edema. During cesarean section, to counterbalance the effect of hypotension caused by spinal anesthesia, anesthesiologists must choose between two fundamental approaches to maintain the hemodynamic state—intravenous fluids or vasopressors—and this choice will depend upon their particular opinions and experience. We aim to assess for any correlations between thoracic ultrasound A- and B-line artifacts, brain natriuretic peptide (BNP) levels, and the amount of intraoperative fluids administered.

Results

From December 2016 to August 2018, at the University-Hospital of Udine, we enrolled 80 consecutive pregnant women undergoing cesarean section. We observed a statistically significant difference in the volume of fluids administered in the first 24 h (p = 0.035) between the patients presenting B-lines in at least one basal area of their thoracic ultrasound and patients with no evident B-lines (AUC 66.4%; IC 0.49–0.83). Dividing the population on whether their BNP levels were higher or less than 20 pg/mL, no statistically significant difference was revealed with regard to fluids administered in the first 24 h (p = 0.537).

Conclusions

Thoracic ultrasound is a non-invasive and easy-to-use tool for detecting fluid intolerance in pregnant women undergoing cesarean section. BNP levels were slow to rise following the cesarean section and did not show any clear correlation with fluid volumes administered.

Cardiovascular Outcomes in Advanced Maternal Age Delivering Women. Clinical Review and Medico-Legal Issues

Background and objecives: Adverse cardiovascular outcomes during pregnancy have increased over the past few decades, with increased numbers of women delivering later in their reproductive life. Other factors include higher rates of female obesity, diabetes, hypertension, cardiovascular diseases and assisted reproductive technology, which has extended fertility. Those at risk require extensive prenatal maternal screening, constant pregnancy supervising, monitoring during labor, delivery and puerperium and careful anesthetic evaluation during delivery. Materials and Methods: The present review reports the relevant information available on cardiovascular outcomes in advanced maternal age delivering women and related medico-legal issues. The search was performed on Pubmed, Cochrane, Semantic Scholar, Medline and Embase databases, accessed by Ovid, including among others the terms "cardiomyopathy", "ischaemic heart disease", "arrhythmias", "hypertension", "peripartum period", "diabetes", "advanced maternal age" "anesthesia", "maternal morbidity and mortality" and "litigation". Results: To the extent that underestimating risk factors for peripartum cardiomyopathy (PPCM) can adversely impact maternal and fetal outcomes, the legal implications of misdiagnosis or mismanagement can result in high compensatory damages. Substantial indemnity payments drive up costs of insurance coverage. Conclusions: Multidisciplinary approaches are necessary from obstetricians, cardiologists, anesthesiologists and perinatologists for pregnancy monitoring and delivery outcomes.

Preoperative anxiety can cause convulsion and severe hypotension immediately after spinal anaesthesia for caesarean delivery: a case report

Preoperative anxiety in patients under spinal anaesthesia may cause serious complications. We report a case of combined transient convulsion and severe hypotension immediately after spinal anaesthesia for caesarean delivery in a patient who presented with severe preoperative anxiety. Our patient’s consciousness and blood pressure recovered normally without any sequelae. However, preoperative anxiety can induce such complications, particularly in patients under regional anaesthesia. Therefore, early detection and deliberate management for preoperative anxiety are required for the patient’s safety and satisfaction.

Nonpneumatic Anti-Shock Garment versus Intermittent Sequential Compression Device for Prevention of Postspinal Hypotension in Patients Undergoing Cesarean Section: A Randomized Controlled Study

Context

Postspinal hypotension remains a frequent complication of subarachnoid block during cesarean section causing further maternal and fetal adverse effects.

Aims

This study aims to evaluate and compare a continuous pressure nonpneumatic anti-shock garment (NASG) and an intermittent sequential compression device (SCD) with a control group for prevention of postspinal hypotension in women undergoing elective cesarean section.

Settings and Design

A randomized, observer blind, controlled study at single university hospital.

Subjects and Methods

Ninety singleton term parturients between 18 and 35 years of age undergoing cesarean section with spinal anesthesia were randomly assigned to be applied with NASG, SCD, or no device; n = 30 in each group. A standardized protocol for cohydration and anesthetic technique was followed. The primary outcome measure was incidence of hypotension defined as a decrease in systolic blood pressure of more than 20% from baseline or an absolute value <100 mmHg, whichever was higher. The secondary outcome measures were median dose of ephedrine required, incidence of maternal nausea and vomiting, and neonatal Apgar scores.

Statistical Analysis Used

Results were expressed as mean (±standard deviation), median (range), or number (%) as appropriate. Nominal data were compared using Chi-square/Fischer's exact test. Continuous data were compared using ANOVA one-way test. Nonparametric data were compared using Kruskal-Wallis test.

Results

In Groups NASG, SCD, and C, incidence of hypotension was 60%, 83%, and 90%, respectively (P = 0.021), with significant reduction in incidence of hypotension in Group NASG versus Group C (P < 0.001, odds ratio 0.17, 95% confidence interval 0.04-0.68). Median (interquartile range) dose of ephedrine required was significantly less in Group NASG compared with Groups SCD and C, respectively (P = 0.002, P < 0.001).

Conclusions

NASG proved to be a more effective device for prevention of postspinal hypotension when compared with application of SCD or no device.

Vasopressors for the management of maternal hypotension during cesarean section under spinal anesthesia: A Systematic review and network meta-analysis protocol

BACKGROUND

Spinal anesthesia is the standard technique for elective cesarean section, but the incidence of maternal hypotension in this setting is reportedly about 80%, without any prophylactic management. Vasopressors are the most reliable method for counteracting the hypotension induced by spinal anesthesia. However, studies investigating the effects of vasopressors have yielded inconsistent and debatable results. Therefore, we plan to conduct a systematic review and network meta-analysis to identify the most effective vasopressor to prevent maternal hypotension, and to decrease fetal acidosis in women undergoing spinal anesthesia for elective cesarean section.

METHODS

A systematic and comprehensive search to detect all the randomized controlled studies on vasopressors for the management of maternal hypotension during cesarean section under spinal anesthesia will be performed using information in the databases, MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar, beginning from their inception to October 2018. We will conduct a network meta-analysis to combine the direct and indirect comparisons of the vasopressors. We will use the surface under the cumulative ranking curve (SUCRA) values and rankograms to present the hierarchy of vasopressors. A comparison-adjusted funnel plot will be used to assess the presence of small-study effects. The quality of the studies included will be assessed using the risk of bias tool. All statistical analyses will be performed using Stata SE version 15.0.

ETHICS AND DISSEMINATION

This systematic review and meta-analysis will be published in a peer-reviewed journal. Ethical approval and informed consent are not required, as the study will be a literature review and will not involve direct contact with patients or alterations to patient care.

TRIAL REGISTRATION NUMBER

The protocol for this review has been registered in the PROSPERO network (registration number: CRD42018111852).

Ondansetron Is an Effective Alternative to Decrease the Incidence of Postspinal Hypotension in Healthy Subjects Undergoing Infra-Umbilical Surgeries Compared To Combined Volume Loading and Vasoconstrictors: Randomized Controlled Trial

BACKGROUND:

One of the important and predicted physiological effects of spinal anaesthesia is hypotension. A range of strategies including mechanical interventions, intravenous fluids and vasoconstrictor drugs have been used to minimise or prevent spinal anaesthesia-induced hypotension. Observational studies suggest that ondansetron reduces the incidence of post-spinal hypotension (PSH) and support the use of combined fluid preloading and vasoconstrictors for this purpose (but with limited doses) to avoid side effects as fluid overload and tachycardia respectively.

AIM:

As no RCT had ever compared the use of Ondansetron alone with combined vasoconstrictors and fluid preload, so, this randomised controlled trial has evaluated the efficacy of the use of ondansetron alone compared to the combined use of fluid preload and vasoconstrictors to decrease the incidence of spinal hypotension.

METHODS:

Ninety patients of ASA grade I between the age of 18 and 45 years scheduled to undergo elective surgical procedures on the lower extremity or lower abdomen under spinal anaesthesia were included in the study. The patients were randomly allocated into two groups of 45 each. Group I patients (ondansetron group) received 4 mg ondansetron in 5 ml normal saline (IV) 15 minutes before induction of spinal anaesthesia. Group II patients (combination group) received preloading with 7.5 ml/kg/min of Ringer’s lactate over 10 minute period preceding the spinal block followed by intravenous bolus of 2.5 mg ephedrine in the first and second minute and 2.5 mg ephedrine every 5 minutes for the next 20 minutes after the injection of spinal anesthetic drug. Non-invasive measurement of mean arterial pressures, heart rate, reactive hypertension, nausea and vomiting were documented.

RESULTS:

The incidence of hypotension following the subarachnoid block in Group I (ondansetron group) was 17.6% versus group II (combination group) was 13.3%, while difference among the groups is statistically insignificant (P = 0.082). Group IV fluids alone could reverse hypotension in 57.1% of patients in group I 33.3% in group II. 42.9% of patients in group I and 67.7% in group II could not be managed with IV fluids alone and had to be treated with 5 mg boluses of ephedrine for reversal of hypotension. The difference in the mean number of fluid boluses and a dose of ephedrine used between both groups was statistically insignificant (P = 0.11 and P = 0.21). HR showed a significant increase in group II and a statistically insignificant change in group I with a statistically significant difference in the heart rate (HR) between both groups (P < 0.05). Reactive hypertension, nausea and vomiting between both groups were statistically insignificant.

CONCLUSION:

The preemptive use of Ondansetron alone versus combined vasoconstrictors with fluid preload significantly reduces the incidence of post-spinal hypotension (PSH) with no significant difference between both regimens. Furthermore, they also reduced consumption of the used vasoconstrictors and fluids to correct hypotension.

Crystalloid coloading vs. colloid coloading in elective Caesarean section: postspinal hypotension and vasopressor consumption, a prospective, observational clinical trial

BACKGROUND

Maternal hypotension is a common side effect of spinal anaesthesia for Caesarean section. The combination of colloid coloading and vasopressors was considered our standard for its prevention and treatment. As the safety of hydroxyethyl starch is under debate, we replaced colloid with crystalloid coloading.

OBJECTIVE

We hypothesize that the mean blood pressure drop is greater when coloading with crystalloids.

DESIGN

Prospective, observational clinical trial.

SETTING

Two-centre study conducted in Berlin, Germany.

PATIENTS

Parturients scheduled for a Caesarean section were screened for eligibility.

INTERVENTION

The study protocol and patient monitoring were based on the standard operating procedure for Caesarean section in both centres. The data from the crystalloid group were prospectively collected between November 2014 and July 2015.

MAIN OUTCOME MEASURES

The primary endpoint was the median drop in mean blood pressure after induction of spinal anaesthesia. Secondary endpoints were incidence of hypotension (drop > 20% of baseline systolic pressure /drop < 100 mmHg), vasopressor and additional fluid requirements (mL), incidence of bradycardia (heart rate < 60 beats per minute), blood loss, Apgar score, and umbilical artery pH. In case of hypotension, patients received phenylephrine or cafedrine/theodrenaline according to their heart rate. A p < 0.05 was considered significant.

RESULTS

345 prospectively enrolled patients (n = 193 crystalloid group vs. n = 152 colloid group) were analysed. The median drop in mean blood pressure was greater in the crystalloid group [34 mmHg (25; 42 mmHg) vs. 21 mmHg (13; 29 mmHg), p < 0.001]. Incidences of hypotension [93.3% vs. 83.6%, p: 0.004] and bradycardia [19.7% vs. 9.9%, p: 0.012] were also significantly greater in the crystalloid group. Vasopressor requirements, blood loss and neonatal outcome were not different between the groups.

CONCLUSIONS

Crystalloid coloading was associated with a greater drop in mean blood pressure and a higher incidence of hypotension when compared with colloid coloading. Neonatal outcome was, however, unaffected by the type of fluid.

TRIAL REGISTRATION

DRKS00006783 ( http://www.drks.de ).

Association between intraoperative phenylephrine administration and umbilical artery pH in women with hypertensive disorders of pregnancy: a retrospective cohort study

PURPOSE

In healthy pregnant women undergoing Cesarean section, treatment of post-spinal hypotension (PSH) with phenylephrine is reportedly more efficacious than ephedrine in preventing a decline in umbilical artery pH (UApH), which is an indicator of fetal acidosis. However, phenylephrine has the potential to reduce placental blood flow and consequently decrease UApH in women who develop hypertensive disorders of pregnancy (HDP), due to decreased cardiac function and placental vascular abnormalities. We aimed to verify the association between decreased UApH and phenylephrine administered before delivery to treat PSH in women with HDP.

METHODS

This single-center retrospective cohort study was conducted between April 2008 and October 2016 by assessing the records of pregnant women with confirmed or suspected HDP who underwent Cesarean section under spinal anesthesia. The association between phenylephrine and the primary endpoint of decreased UApH was investigated using logistic regression analysis and propensity score matching.

RESULTS

In the original cohort of 107 pregnant women with HDP, neither univariate nor multivariate analysis indicated a significant association between phenylephrine treatment and decreased UApH [crude odds ratio (OR) = 2.26; 95% confidence interval (CI) 0.75-6.77; P = 0.14], (adjusted OR = 1.80; 95% CI 0.55-5.93; P = 0.33). Thirty patients each who were not treated with phenylephrine (control group) and were treated with phenylephrine (phenylephrine group) were matched by propensity score analysis. UApH [median (interquartile range)] was not significantly different between control and phenylephrine groups [7.30 (7.25-7.35) vs. 7.27 (7.25-7.30); P = 0.14].

CONCLUSION

Intraoperative phenylephrine administration to treat PSH in women with HDP was not associated with decreased UApH.

Minimal effective weight-based dosing of ondansetron to reduce hypotension in cesarean section under spinal anesthesia: a randomized controlled superiority trial

BACKGROUND

The weight-based dosing of ondansetron to reduce hypotension has never been investigated. The aim of this study is to determine the optimal dose of ondansetron required based on the patient's weight to reduce hypotension following spinal anesthesia for cesarean section.

METHODS

In this prospective, triple-blinded, parallel group, randomized controlled trial, a total of 228 pregnant women were randomized to receive either normal saline (group NS) or ondansetron 0.05 mg/kg (group O1) or ondansetron 0.1 mg/kg (group O2) intravenously 5 min before induction of spinal anesthesia. The incidence of hypotension, mean arterial pressure, heart rate, vasopressor requirements, and blood loss between the three groups were compared. Maternal and neonatal complications were also assessed. Changes in blood pressure and heart rate were compared using the generalized estimating equations method.

RESULTS

Thirteen patients were excluded from the analysis because of no intervention (n = 12) and protocol violation (n = 1). Two hundred and fifteen patients remained for the intention-to-treat analysis. The incidence of hypotension in groups NS (n = 72), O1 (n = 71), and O2 (n = 72) were 81.9%, 84.5%, and 73.6%, respectively (P = 0.23). The episodes of hypotension before delivery (first 14 min after spinal anesthesia) were significantly higher in group O1 compared to NS (5 vs 2, P = 0.02). The overall heart rates throughout the operations were not different among the three groups. The ephedrine requirements and amount of blood loss were also similar among the three groups. The metoclopramide requirement was significantly lower in group O2 compared to group NS (2.8% vs 16.7%, P = 0.01). There were no serious adverse events in terms of maternal or neonatal complications.

CONCLUSIONS

Ondansetron 0.05 mg/kg or 0.1 mg/kg administered before spinal anesthesia did not reduce the incidence of hypotension in this study.

TRIAL REGISTRATION

Thai Clinical Trials Registry, TCTR 20160323001 , 22 March 2016.

A three minutes supine position test reveals higher risk of spinal anesthesia induced hypotension during cesarean delivery. An observational study

Background: Cesarean delivery is performed under spinal anesthesia, and vasodilation is the main cause for a drop in blood pressure. The compression of the aorta and inferior vena cava by the gravid uterus is of additional clinical importance. Hypotension may occur during cesarean delivery even if prophylactic infusion of phenylephrine is practiced. We have tested if a 3 minute supine observation, can identify a subset of women with decreasing systolic arterial pressure (SAP) under spinal anesthesia. Methods: We performed a prospective observational study at Oslo University Hospital on healthy pregnant women for planned cesarean delivery. Continuous measurements of calibrated invasive SAP and estimated cardiac output were recorded for 76 women in a 3 minutes measurement with the woman in the left lateral position, followed by supine position for 3 minutes. Using functional data clustering, principal component analysis and curve smoothing, to filter way noise and reduce the dimensionality of the signal, we clustered the women into separate SAP groups.   Results: We identified two significantly different groups of women during supine position; one characterized by initial drop in SAP, the other showed initial increase. After spinal anesthesia, the mean SAP curve of the women in the first group showed a drop in blood pressure, which was more rapid than for the other women. A minor difference in cardiac output was observed between the two groups of women with the mean cardiac output curve for the first group being higher. Conclusions: This work indicates that supine position affect clinically relevant cardiovascular measurements in pregnant women. A simple test may identify patients with increased risk of spinal anesthesia induced hypotension.

Impedance cardiography as tool for continuous hemodynamic monitoring during cesarean section: randomized, prospective double blind study

BACKGROUND

Impedance Cardiography (ICG) is a non-invasive tool for continuous hemodynamic monitoring. Aims of our study were to assess the utility of ICG to evaluate the hemodynamic impact of 6 mg (GL6) vs 8 mg (GL8) levobupivacaine combined with fentanyl in healthy patients undergoing elective cesarean section; secondary, to compare the duration and quality of analgesia and anesthesia.

METHODS

Sixty-two women receiving combined spinal-epidural (CSE) for elective cesarean delivery were randomly allocated to GL6 or GL8 groups. Mean arterial pressure (MAP), cardiac index (CI), systemic vascular resistance index (SVRI), heart rate (HR), stroke volume index (SVI) were recorded from Tbaseline to 31 min after CSE by ICG. Sensory and motor blocks, patients and surgeons satisfaction, neonatal data were also recorded.

RESULTS

Fifteen of 32 patients in GL6 and 15 of 30 patients in GL8 experienced hypotension at T2 vs Tbaseline (P < .001) and SVRI reduction (P = .035 and P < .001 respectively). MAP, CI and SVRI were always slightly higher in GL6 vs GL8. HR and SVI remained stable until the end of surgery in all patients. Total ephedrine requirements was higher in GL8 (P = .010). The onset and offset time of sensory and motor block were similar in both groups, but the number of patients with motor block was lower in GL6 vs GL8 (P = .001). Patients and surgeon satisfaction scores, the number of patients needed systemic rescue doses, neonatal data were similar in both groups.

CONCLUSIONS

ICG is a useful noninvasive tool to monitor continuously hemodynamics during cesarean section. The hemodynamic stability, the satisfying sensory block and rapid mobilization provided by low levobupivacaine dose may be particularly advantageous in obstetric patients.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03170427 . Retrospectively Registered (Date of registration: May 2017).

Study Comparing Phenylephrine Bolus and Infusion for Maternal Hypotension and Neonatal Outcome during Cesarean Section under Spinal Anesthesia

Background

Phenylephrine(PE) bolus and infusion have been compared for post spinal hypotension and neonatal effects during cesarean section(CS) under spinal anesthesia(SA).

Aim

The primary aim of this study was to compare bolus doses of 50μg of PE with a fixed infusion rate of 50 μg/min of the same drug given prophylactically. The secondary aim was to study the neonatal outcome and side effects with the two regimes.

Settings and Design

This prospective,randomized,comparative study was conducted in the department of Anesthesia in a tertiary care teaching hospital.

Materials and Methods

This study was conducted on 100 normotensive women undergoing CS under SA. The patients were randomized into two groups of 50 each. Group A received bolus of 50 μg PE after the systolic BP(SBP) fell by 20% from the baseline and Group B received a prophylactic infusion of 50 μg/min PE. The changes in heart rate (HR), BP and side effects were compared till delivery. The neonatal APGAR scores were compared at 1 and 5 minutes and an umbilical artery sample was sent for blood gas analysis.

Statistical Analysis

Categorical variables were shown in number and percentage. Normally distributed continuous variables were presented as mean ± SD and compared using unpaired t-test. Non normally distributed continuous variables were displayed as median and were compared using Mann-Whitney test. A P value of <0.05 was considered significant.

Results

In group A, the HR was higher than in group B throughout the monitoring period. (P < 0.001). In group A, SBP trend showed a fall of more than 20% from the base line in 44 patients. The mean fall in SBP was -28.06 ± 5.3 mmHg% in Group A while in group B the mean fall in SBP was only -0.44 ± 4.3mmHg%. Nausea and vomiting was less in group B. There was no difference in APGAR or neonatal acidosis on ABG.

Conclusion

There was a tighter control of BP in the infusion group vs. the bolus group while the neonatal outcome was similar in both the groups.

Norepinephrine versus Ephedrine to Maintain Arterial Blood Pressure during Spinal Anesthesia for Cesarean Delivery: A Prospective Double-blinded Trial

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.

Preventing nausea and vomiting in women undergoing regional anesthesia for cesarean section: challenges and solutions

BACKGROUND

Intraoperative nausea and vomiting (IONV) or postoperative nausea and vomiting (PONV) affecting women undergoing regional anesthesia for cesarean section is an important clinical problem since these techniques are used widely. There are burdens of literature about IONV/PONV and several in parturient and cesarean. However, it needs more attention. The underlying mechanisms of IONV and PONV in the obstetrical setting mainly include hypotension due to sympathicolysis during neuraxial anesthesia, bradycardia owing to an increased vagal tone, the visceral stimulation via the surgical procedure and intravenously administered opioids.

METHODS

Given the high and even increasing rate of cesarean sections and the sparse information on the etiology, incidence and severity of nausea and vomiting and the impact of prophylactic measures on the incidence of PONV/IONV, this article aims to review the available information and provide pragmatic suggestions on how to prevent nausea and vomiting in this patient cohort. Current literature and guidelines were identified by electronic database searching (MEDLINE via PubMed and Cochrane database of systematic reviews) up to present, searching through reference lists of included literature and personal contact with experts.

DISCUSSION AND CONCLUSION

Taking into account the current guidelines and literature as well as everyday clinical experience, the first step for decreasing the incidence of IONV and PONV is a comprehensive management of circulatory parameters. This management includes liberal perioperative fluid administration and the application of vasopressors as the circumstances require. By using low-dose local anesthetics, an additional application of intrathecal or spinal opioids or hyperbaric solutions for a sufficient controllability of neuraxial distribution, maternal hypotension might be reduced. Performing a combined spinal-epidural anesthesia or epidural anesthesia may be considered as an alternative to spinal anesthesia. Antiemetic drugs may be administered restrainedly due to off-label use in pregnant women for IONV or PONV prophylaxis and may be reserved for treatment.

Techniques for preventing hypotension during spinal anaesthesia for caesarean section

BACKGROUND

Maternal hypotension is the most frequent complication of spinal anaesthesia for caesarean section. It can be associated with nausea or vomiting and may pose serious risks to the mother (unconsciousness, pulmonary aspiration) and baby (hypoxia, acidosis, neurological injury).

OBJECTIVES

To assess the effects of prophylactic interventions for hypotension following spinal anaesthesia for caesarean section.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (9 August 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials, including full texts and abstracts, comparing interventions to prevent hypotension with placebo or alternative treatment in women having spinal anaesthesia for caesarean section. We excluded studies if hypotension was not an outcome measure.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted data from eligible studies. We report 'Summary of findings' tables using GRADE.

MAIN RESULTS

We included 126 studies involving 9565 participants. Interventions were to prevent maternal hypotension following spinal anaesthesia only, and we excluded any interventions considered active treatment. All the included studies reported the review's primary outcome. Across 49 comparisons, we identified three intervention groups: intravenous fluids, pharmacological interventions, and physical interventions. Authors reported no serious adverse effects with any of the interventions investigated. Most trials reported hypotension requiring intervention and Apgar score of less than 8 at five minutes as the only outcomes. None of the trials included in the comparisons we describe reported admission to neonatal intensive care unit. Crystalloid versus control (no fluids)Fewer women experienced hypotension in the crystalloid group compared with no fluids (average risk ratio (RR) 0.84, 95% confidence interval (CI) 0.72 to 0.98; 370 women; 5 studies; low-quality evidence). There was no clear difference between groups in numbers of women with nausea and vomiting (average RR 0.19, 95% CI 0.01 to 3.91; 1 study; 69 women; very low-quality evidence). No baby had an Apgar score of less than 8 at five minutes in either group (60 babies, low-quality evidence). Colloid versus crystalloidFewer women experienced hypotension in the colloid group compared with the crystalloid group (average RR 0.68, 95% CI 0.58 to 0.80; 2105 women; 28 studies; very low-quality evidence). There were no clear differences between groups for maternal hypertension requiring intervention (average RR 0.64, 95% CI 0.09 to 4.46, 3 studies, 327 women;very low-quality evidence), maternal bradycardia requiring intervention (average RR 0.99, 95% CI 0.55 to 1.79, 6 studies, 509 women; very low-quality evidence), nausea and/or vomiting (average RR 0.83, 95% CI 0.61 to 1.13, 15 studies, 1154 women, I² = 37%; very low-quality evidence), neonatal acidosis (average RR 0.83, 95% CI 0.15 to 4.52, 6 studies, 678 babies; very low-quality evidence), or Apgar score of less than 8 at five minutes (average RR 0.24, 95% CI 0.03 to 2.05, 11 studies, 826 babies; very low-quality evidence). Ephedrine versus phenylephrineThere were no clear differences between ephedrine and phenylephrine groups for preventing maternal hypotension (average RR 0.92, 95% CI 0.71 to 1.18; 401 women; 8 studies; very low-quality evidence) or hypertension (average RR 1.72, 95% CI 0.71 to 4.16, 2 studies, 118 women, low-quality evidence). Rates of bradycardia were lower in the ephedrine group (average RR 0.37, 95% CI 0.21 to 0.64, 5 studies, 304 women, low-quality evidence). There was no clear difference in the number of women with nausea and/or vomiting (average RR 0.76, 95% CI 0.39 to 1.49, 4 studies, 204 women, I² = 37%, very low-quality evidence), or babies with neonatal acidosis (average RR 0.89, 95% CI 0.07 to 12.00, 3 studies, 175 babies, low-quality evidence). No baby had an Apgar score of less than 8 at five minutes in either group (321 babies; low-quality evidence). Ondansetron versus controlOndansetron administration was more effective than control (placebo saline) for preventing hypotension requiring treatment (average RR 0.67, 95% CI 0.54 to 0.83; 740 women, 8 studies, low-quality evidence), bradycardia requiring treatment (average RR 0.49, 95% CI 0.28 to 0.87; 740 women, 8 studies, low-quality evidence), and nausea and/or vomiting (average RR 0.35, 95% CI 0.24 to 0.51; 653 women, 7 studies, low-quality evidence). There was no clear difference between the groups in rates of neonatal acidosis (average RR 0.48, 95% CI 0.05 to 5.09; 134 babies; 2 studies, low-quality evidence) or Apgar scores of less than 8 at five minutes (284 babies, low-quality evidence). Lower limb compression versus controlLower limb compression was more effective than control for preventing hypotension (average RR 0.61, 95% CI 0.47 to 0.78, 11 studies, 705 women, I² = 65%, very low-quality evidence). There was no clear difference between the groups in rates of bradycardia (RR 0.63, 95% CI 0.11 to 3.56, 1 study, 74 women, very low-quality evidence) or nausea and/or vomiting (average RR 0.42 , 95% CI 0.14 to 1.27, 4 studies, 276 women, I² = 32%, very-low quality evidence). No baby had an Apgar score of less than 8 at five minutes in either group (130 babies, very low-quality evidence). Walking versus lyingThere was no clear difference between the groups for women with hypotension requiring treatment (RR 0.71, 95% CI 0.41 to 1.21, 1 study, 37 women, very low-quality evidence).Many included studies reported little to no information that would allow an assessment of their risk of bias, limiting our ability to draw meaningful conclusions. GRADE assessments of the quality of evidence ranged from very low to low. We downgraded evidence for limitations in study design, imprecision, and indirectness; most studies assessed only women scheduled for elective caesarean sections.External validity also needs consideration. Readers should question the use of colloids in this context given the serious potential side effects such as allergy and renal failure associated with their administration.

AUTHORS' CONCLUSIONS

While interventions such as crystalloids, colloids, ephedrine, phenylephrine, ondansetron, or lower leg compression can reduce the incidence of hypotension, none have been shown to eliminate the need to treat maternal hypotension in some women. We cannot draw any conclusions regarding rare adverse effects associated with use of the interventions (for example colloids) due to the relatively small numbers of women studied.

Leg elevation decreases the incidence of post-spinal hypotension in cesarean section: a randomized controlled trial

Background

Maternal hypotension is a common complication after spinal anesthesia for cesarean section (CS). In this study we investigated the role of leg elevation (LE) as a method for prevention of post-spinal hypotension (PSH) for cesarean section.

Methods

One hundred and fifty full term parturients scheduled for CS were included in the study. Patients were randomized into two groups: Group LE (leg elevation group, n = 75) and group C (Control group, n = 75). Spinal block was performed in sitting position after administration of 10 mL/Kg Ringer’s lactate as fluid preload. After successful intrathecal injection of local anesthetic, Patients were positioned in the supine position. Leg elevation was performed for LE group directly after spinal anesthesia and maintained till skin incision. Intraoperative hemodynamic parameters (Arterial blood pressure and heart rate), intra-operative ephedrine consumption, incidence of PSH, and incidence of nausea and vomiting were reported.

Results

LE group showed lower incidence of PSH (34.7% Vs 58.7%, P = 0.005) compared to the control group. Arterial blood pressure was higher in the LE group compared to the control group in the first two readings after spinal block. Other readings showed comparable arterial blood pressure and heart rate values between both study groups; however, LE showed less ephedrine consumption (4.9 ± 7.8 mg Vs 10 ± 11 mg, P = 0.001).

Conclusion

LE performed immediately after spinal block reduced the incidence of PSH in parturients undergoing CS.

Trial registration

The study was registered at Pan African Clinical Trials Registry system on 5/10/2015 with trial number PACTR201510001295348.

Intrapartum intravenous fluids for caesarean delivery and newborn weight loss: a retrospective cohort study

OBJECTIVE

To examine weight loss (WL) and excess weight loss (EWL) among newborns of caesarean delivery, comparing colloids plus crystalloids versus crystalloids only. Also, to examine different doses of intrapartum intravenous fluids on WL and EWL.

DESIGN

Comparative safety retrospective cohort study.

SETTING

University Teaching Hospital, Moncton, Canada.

PATIENTS

Mothers exposed to intravenous fluids with caesarean delivery between 2008 and 2016.

INTERVENTIONS

Exposure to colloids plus crystalloids was compared with crystalloids only, and dose-response analyses were performed for colloids, crystalloids and total intravenous fluids doses. Linear and logistic regression models were used, adjusting for potential confounders.

MAIN OUTCOME MEASURES

Infants' WL was measured at days 1, 2 and 3 post partum, and EWL defined as loss of >7% of birth weight.

RESULTS

From 801 mother-infant pairs, 176 were exposed to colloids plus crystalloids and 625 were exposed to crystalloids only (overall mean birth weight=3416 g, EWL=2%, 41.4% and 55.5% on days 1, 2 and 3, respectively). No significant difference in newborns' WL was observed on any of the days assessed. Adjusted OR (95% CI) of EWL was 1.0 (0.3 to 3.3) at 24 hours, 1.0 (0.7 to 1.5) at 48 hours and 1.4 (0.9 to 2.2) at 72 hours. No dose-response relationship was detected with type-specific and total intravenous fluids exposures.

CONCLUSIONS

The risk of EWL was similar with colloids plus crystalloids and crystalloids only, suggesting that both therapeutic options can be considered during caesarean delivery. The absence of dose-response relationships adds confirmatory evidence to the intravenous fluids safety profiles.

Reducing by 50% the incidence of maternal hypotension during elective caesarean delivery under spinal anesthesia: Effect of prophylactic ondansetron and/or continuous infusion of phenylephrine - a double-blind, randomized, placebo controlled trial

Background:

Prophylactic administrations of ondansetron or phenylephrine have been reported to provide a protective effect against hypotension in women undergoing cesarean delivery under spinal anesthesia (SA). The main hypothesis is that ondansetron improves the hemodynamic response, especially combined with phenylephrine infusion.

Methods:

This prospective, double-blind, randomized, placebo-controlled study included 265 healthy pregnant women scheduled for elective cesarean delivery under SA. Women were randomly allocated into four groups to receive either placebo (control), ondansetron (O) 8 mg intravenously before induction of SA, phenylephrine infusion (50 mcg/min) (P) or ondansetron plus phenylephrine (OP). Demographic, obstetric, intraoperative timing, and anesthetic variables were assessed at 16 time points. Anesthetic variables assessed included blood pressure, heart rate, oxygen saturation, nausea, vomiting, electrocardiographic changes, skin flushing, discomfort or pruritus, and vasopressor requirements.

Results:

There were differences (P = 0.0001) in the number of patients with hypotension (50.8% control, 44.6% O, 20.9% P, 25.0% OP), the percentage of time points (P = 0.0001) with systolic hypotension per patient (17.4% control, 8.7% O, 2.1% P, 6.7% OP) and the number of patients requiring supplementary boluses of ephedrine (P = 0.003), phenylephrine (P = 0.017) or atropine (P = 0.0001).

Conclusions:

A 50 μg/min phenylephrine infusion reduces by 50%, the incidence of maternal hypotension compared with placebo, but infusions of phenylephrine are still not routine in our environment. Prophylactic ondansetron 8 mg might be considered in this situation, because it does not reduce the incidence of maternal hypotension but diminishes its severity, reducing the number of hypotensive events per patient by 50%.

Phenylephrine infusion for spinal-induced hypotension in elective cesarean delivery: Does preload make a difference?

Background and Aims:

Patients undergoing elective cesarean delivery (CD) have a high-risk of spinal-induced hypotension (SIH). We hypothesized that a colloid preload would further reduce SIH when compared with a crystalloid preload.

Material and Methods:

Eighty-two healthy parturients undergoing elective CD were included in the study. Patients were randomly assigned to two groups (41 patients in each group) to receive either Lactated Ringer's solution (1500 ml) or hydroxyethyl starch (6% in normal saline, 500 ml) 30 min prior to placement of spinal anesthesia. All patients were treated with a phenylephrine infusion (100 mcg/min), titrated during the study.

Results:

There was no statistical difference between groups with regards to the incidence of hypotension (10.8% in the colloid group vs. 27.0% in the crystalloid group, P = 0.12). There was also no difference between groups with respect to bradycardia, APGAR scores, and nausea and vomiting. Significantly less phenylephrine (1077.5 ± 514 mcg) was used in the colloid group than the crystalloid group (1477 ± 591 mcg, P = 0.003).

Conclusion:

The preload with 6% of hydroxyethyl starch before CD might be beneficial for the prevention of SIH.

Sufentanil in combination with low-dose hyperbaric bupivacaine in spinal anesthesia for cesarean section: a randomized clinical trial

A double blind randomized clinical trial of sufentanil as an adjunct in spinal anesthesia for cesarean section and, thereby, be able to reduce the dose of bupivacaine, a local anesthetic, with the same result of an anesthetic block with higher doses but with fewer perioperative side effects, such as hypotension.

Peripartum events and molar-incisor hypomineralisation (MIH) amongst young patients in southwest France

AIM

This was to investigate the association of peripartum events with the occurrence of MIH.

METHODS

This study, carried out between 2010 and 2011, was based on objective information noted in child health booklets on putative risk factors for MIH during the Peripartum period, aged between 6 to 28 years. The target population consisted of patients with MIH and a control group. Among the 849 patients examined by two calibrated paediatric dentists, 75 patients with MIH were recorded. These patients attended for consultation either at the teaching dental hospital of Bordeaux (France) or at a private dental practice (Bordeaux, France). Pearson's Chi-squared test was used and Odds ratios (OR) with 95 % test-based confidence intervals (CI) were calculated.

RESULTS

Correlations were observed between hypoxia during delivery and occurrence of MIH (OR = 6.1; CI = 1.7-21.85), and also between birth by caesarean section and MIH (OR = 2.9; CI = 1.2-6.9). There was no association between prematurity and MIH.

CONCLUSIONS

Peripartum events such as hypoxia during birth or delivery by caesarean section are suggested to be risk factors for the occurrence of MIH in this population.

Effects of hydroxyethyl starch 6 % (130/0.4) on blood loss during cesarean delivery: a propensity-matched analysis

BACKGROUND

Hydroxyethyl starch is commonly used in the obstetric patient population to prevent hypotension during cesarean delivery. Evidence suggests hetastarch is associated with a dysfunction in coagulation cascade. We hypothesized that hetastarch use to prevent spinal hypotension during cesarean delivery would be associated with an increase in blood loss when compared to crystalloid use.

METHODS

We performed a retrospective review of patients who underwent elective cesarean delivery under spinal anesthesia at the University of Virginia between 2011 and 2014. Data from 819 patients was used. Blood loss was the primary outcome. Propensity score-matching was used to match patients who received hetastarch (treatment group) with those who did not receive hetastarch (control group).

RESULTS

Genetic matching resulted in 196 patients in the hetastarch group and 182 patients in the control group. There was no difference in estimated blood loss (p = 0.068), calculated blood loss (p = 0.720), total intraoperative fluid intake (p = 0.289), urine output (p = 0.421), Apgar 1 min (p = 0.830), Apgar 5 min (p = 0.138), phenylephrine consumption (p = 0.742), postoperative day 1 (POD1) hematocrit (p = 0.070) and POD1 platelets (p = 0.233). However, there was a statistically significant difference (but clinically irrelevant) in hematocrit difference between the day of admission and POD1 (mean difference 0.47, p = 0.024), and ephedrine consumption (mean difference 2 mg, p = 0.017) in favor of the control group.

CONCLUSIONS

Our study did not find an association between increased perioperative blood loss and hetastarch use in patients presenting for elective cesarean delivery.

A randomised controlled trial comparing weight adjusted dose versus fixed dose prophylactic phenylephrine infusion on maintaining systolic blood pressure during caesarean section under spinal anaesthesia

BACKGROUND

Spinal anaesthesia is the standard of care for elective caesarean delivery. It has advantages over general anaesthesia. However the sympathetic blockade induced by spinal anaesthesia results in an 80 percent incidence of hypotension without prophylactic management. Current evidence supports co-loading with intravenous fluids in conjunction with the use of vasopressors as the most effective way to prevent and treat the hypotension. Phenylephrine is the accepted vasopressor of choice in the parturient. A prophylactic phenylephrine infusion combined with a fluid co-load is proven to be an effective and safe method of maintaining maternal hemodynamic stability. While most published studies have assessed the effectiveness of a prophylactic phenylephrine fixed dose infusion, few studies have assessed the effect of a prophylactic phenylephrine weight adjusted dose infusion on maintaining maternal hemodynamic stability following spinal anesthesia for a cesarean delivery.

OBJECTIVE

To compare the incidence of hypotension between women undergoing elective caesarean section under spinal anaesthesia, receiving prophylactic phenylephrine infusion at a fixed dose of 37.5 micrograms per minute versus a weight adjusted dose of 0.5 micrograms per kilogram per minute.

METHODS

One hundred and eight patients scheduled for non-urgent caesarean section under spinal anaesthesia were randomized into 2 groups; control group and intervention group using a computer generated table of numbers. Control group; Received prophylactic phenylephrine fixed dose infusion at 37.5 micrograms per minute. Intervention group; Received prophylactic phenylephrine weight adjusted dose infusion at 0.5 micrograms per kilogram per minute.

RESULTS

The two groups had similar baseline characteristics in terms of; Age, sex, weight and height. There was a 35.2% incidence of hypotension in the fixed dose group and an 18.6% incidence of hypotension in the weight adjusted dose group. This difference was found to be of borderline statistical significance p-value 0.05, and the difference in the incidence rates between the two groups was found to be statistically significant p= 0.03. The difference in the incidence of reactive hypertension and bradycardia between the two groups was not statistically significant: p-value of 0.19 for reactive hypertension and p-value of 0.42 for the incidence of bradycardia. There was also no statistically significant difference in the use of phenylephrine boluses, use of atropine, intravenous fluid used and the number of times the infusion was stopped.

CONCLUSION

Among this population, the incidence of hypotension was significantly less in the weight adjusted dose group than in the fixed dose group. There was no difference in the number of physician interventions required to keep the blood pressure within 20% of baseline, and no difference in the proportion of reactive hypertension or bradycardia between the two groups. Administering prophylactic phenylephrine infusion at a weight adjusted dose of 0.5 micrograms per kilogram per minute results in a lower incidence of hypotension compared to its administration at a fixed dose of 37.5 micrograms per minute.

Two syringe spinal anesthesia technique for cesarean section: A controlled randomized study of a simple way to achieve more satisfactory block and less hypotension

BACKGROUND

Multiple trials have been tried to prevent hypotension during spinal anesthesia. However, the drug choice and mode of administration is still a matter of debate.

OBJECTIVES

To compare the outcome of spinal injection of hyperbaric bupivacaine and fentanyl separately to standard injection of mixed fentanyl with hyperbaric bupivacaine.

SETTINGS AND DESIGN

A randomized, controlled clinical trial.

PATIENTS AND METHODS

One hundred twenty-four parturient scheduled for elective cesarean section were randomly allocated into two groups, each 62 parturient: Group M received spinal anesthesia using 10 mg bupivacaine 0.5% premixed with 25 μg fentanyl in the same syringe and Group S received 25 μg fentanyl in one syringe and 10 mg bupivacaine 0.5% without barbotage in a second syringe.

RESULTS

Patients with intraoperative pain that was controllable without the need for a shift to general anesthesia was significantly lower in Group S (3.2%) than in Group M (16.1%). The frequency of hypotension was significantly lower in Group S compared to Group M (P < 0.05). Time till the onset of sensory block was nonsignificantly shorter with nonsignificantly higher mean level of maximal sensory block in Group S compared to Group M (P > 0.05). There was no significant difference in the time till occurrence of hypotension, duration of hypotension, mean dose of ephedrine used for the treatment of hypotension and frequency of patients developed itching between the groups (P > 0.05).

CONCLUSION

Separate intrathecal injection of fentanyl and hyperbaric bupivacaine provided a significant improvement in the quality of sensory block and significant reduction of the frequency of hypotension compared to injection of mixed medications.

Cross-Sectional Guidelines for Therapy with Blood Components and Plasma Derivatives: Chapter 5 Human Albumin - Revised

Chapter 5 'Human Albumin' that was suspended on January 10, 2011 has been completed and updated in the present version.

Circulatory collapse following epidural bolus for Caesarean section a profound vasovagal reaction? A case report

•

Secure adequate hydration before putting a regional block.

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Prepare vaso-active medication, phenylephrine and have ephedrine and atropine readily available.

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Secure adequate lift tilt after block placement.

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Measure blood pressure and heart rate every 3 min.

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React readily to decrease in blood pressure and/or heart rate.

Introduction

Reduced blood pressure is commonly seen associated to spinal anaesthesia for Caesarean section and efforts to reduce its occurrence and its magnitude is common practice. Cardiovascular collapse requiring cardio-pulmonary resuscitation after putting the spinal/epidural block for Caesarean section is however a rare but most dramatic event.

Presentation of case

We describe a case with sudden short loss of circulation, circulatory collapse, short after start of emergency Caesarean section in top up epidural anaesthesia (3 + 12 ml ropivaciane 7.5 mg/ml), requiring CPR. The neonate was delivered during CPR with Apgar 1, 10, 10 at 1, 5 and 10 min. Circulation was restored following 60–90 s of CPR and administration of 0.5 mg adrenaline. No cardioversion was administered sinus rhythm was regained spontaneously. The mother and child had a further uncomplicated course. No signs of cardiac damage/anomaly, emboli, septicaemia, pereclampisa or local anaesthetic toxicity was found. The patient had prior to the decision about Caesarean section had fever and was subsequently relatively dehydrated.

Discussion

The patient had a fast return of sinus rhythm following birth of the child, without cardioversion. None of common causes for cardiac arrest was found and the patient an uncomplicated post Caesarean section course. The combination of epidural induced sympathetic block and reduced preload possibly triggered a Bezold-Jarisch reflex with a profound vasovagal reaction.

Concluiosn

A structured plan for the handling of cardiovascular crisis must be available wherever Caesarean section are performed. Adequate volume loading, left tilt and vigilant control of circulation following regional block performance is of outmost importance.

Ephedrine versus ondansetron in the prevention of hypotension during cesarean delivery: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Maternal hypotension is common after spinal anesthesia for cesarean delivery. We compared the effects of prophylactic ephedrine with ondansetron on post-spinal blood pressure.

METHODS

One hundred and sixty-eight term, singleton parturients were enrolled in this prospective, double-blind, placebo-controlled trial. Patients were randomized to receive either prophylactic intravenous ephedrine 10mg (Group E), ondansetron 8mg (Group O) or normal saline (Group P) immediately after spinal anesthesia. The primary outcome was maternal blood pressure between spinal block and delivery; secondary outcomes were nausea and vomiting scores, Apgar scores, numbers requiring intraoperative vasoconstrictors and the dose of vasoconstrictors required.

RESULTS

Fifty-six patients were recruited to each group, but two in Group P were excluded from the analysis owing to protocol violations. There were no significant differences between the groups in maternal systolic, diastolic or mean arterial pressures, or the proportion of patients experiencing hypotension. The proportion of patients in Group E requiring intraoperative ephedrine or any vasoconstrictor (ephedrine and/or norepinephrine) was significantly lower than that in Group P (P=0.023 and 0.034, respectively). The proportion of patients in Group O requiring intraoperative norepinephrine was significantly lower than that in Group P (P=0.02). There was no difference in the proportions of patients in Groups E and O requiring any vasoconstrictors (P=0.34).

CONCLUSIONS

There was no significant difference in maternal blood pressure in women administered prophylactic ephedrine or ondansetron after spinal anesthesia for cesarean delivery compared with placebo. Ephedrine reduced the proportion of patients requiring a rescue vasoconstrictor before delivery.