Techniques for preventing hypotension during spinal anaesthesia for caesarean section

Is enhanced recovery after surgery essential?

BACKGROUND

The enhanced recovery after surgery (ERAS) method is designed for the patient to recover quickly, have less pain and have a more comfortable period after the surgery; that includes preoperative, intra and postoperative processes. ERAS has been started to be applied in cesarean section surgeries as the patients need to recover quickly. In the literature, there is no study about the results of ERAS in cesarean section about pain scores and complications.

OBJECTIVES

It is aimed to compare the results of cesarean section patients using the ERAS method completely in patients who have had cesarean section without meeting some of the postoperative conditions of the ERAS criteria.

STUDY DESIGN

It is a prospective study designed as postoperative metoclopramide, enema and routine opioids in group 1, enema and metoclopramide in group 2, metoclopramide only in group 3 and nothing in group 4. Postoperative pain scoring was done by using visual analog scale (VAS). Analysis of variance tests and t tests were used for results.

RESULTS

There was no difference between groups according to age, parity, and birth weight. As a result, although there was no difference between the groups in terms of discharge time and complications, the VAS score used in pain scoring was found to be significantly lower in group 3 compared to the other groups (p: 0.000). Only metoclopramide group (group 3) had lowest VAS score.

CONCLUSION

It has been revealed that the ERAS procedure does not need to be so detailed in the postoperative period, and the addition of metoclopramide may be sufficient. Since pain can be a subjective factor, other randomized studies are needed in terms of other criteria.

Comparison of the hemodynamic changes between preeclamptic and normotensive parturients who underwent cesarean section under spinal anesthesia at North Showa zone public hospitals, Oromia region, Ethiopia, 2022: a prospective cohort study

BACKGROUND

Spinal anaesthesia complicates maternal hemodynamic and may expose the parturient to dangerous cardiovascular problems. Up to 7% to 89.2% of pregnant women can suffer from spinal anaesthesia-related hypotension. The aim of this study to compare the hemodynamic changes between preeclamptic and normotensive parturients who underwent caesarean section under spinal anaesthesia at North Showa Zone Public Hospitals, Oromia Region, from February 15 to May 15, 2022.

METHODS

A prospective cohort study was conducted on a total of 140 parturients (70 in each group) who underwent cesarean delivery under spinal anesthesia. The study participants were chosen using a consecutive sampling technique. Data were collected from patient charts and intraoperative observations and entered into the Epi Data software version 4.6 and exported to the Statistical Package for the Social Sciences version 25 software. Hemodynamic change = (baseline value-current value/baseline value) * 100. The independent t-test, Mann-Whitney U test, two ways mixed ANOVA, chi-square, and Fisher's exact test was used to analyze the data as appropriate. A P < 0.05 was statistically significant.

RESULTS

The mean percentage change in SBP, DBP, and MAP after spinal anaesthesia was a statistically significant difference between the normotensive and preeclamptic groups, except MAP at 15 min was comparable between the two groups with p = 0.638. The proportion of preeclamptic parturients who develop hypotension was 47%, compared to 74% of normotensive parturients, and the RR of developing hypotension, if participants were preeclamptic, was 0.63, with a 95% confidence interval of 0.412 to 0.978 and a p = 0.039. The mean change in heart rate during the first 15 min was comparable between the groups.

CONCLUSION

In contrast to normotensive parturients undergoing caesarean section under spinal anaesthesia, our study found that the hemodynamic change was lower in preeclamptic parturients. The proportion of preeclamptic women who develop hypotension was 47%, compared to 74% of normotensive parturients.

The Effect of Maternal Lower Limb Compression on Amniotic Fluid Index, Uteroplacental Perfusion, and Fetal Blood Flow in Isolated Oligohydramnios

INTRODUCTION

The aim of this study was to examine the efficacy of pneumatic compression of the maternal lower extremities in increasing the amniotic fluid index (AFI) in pregnancies complicated by isolated oligohydramnios.

METHODS

Women with isolated oligohydramnios (AFI <5 cm) at 32-41 weeks of pregnancy were connected to a sequential compression device for 60 min. Prior and after the application, AFI and the pulsatility index (PI) of a number of arteries were measured.

RESULTS

The median (interquartile range) maternal age of the 21 women included was 29 years (26.50-32.00), the median parity was 1 (1-2), and the median gestational age at intervention was 37.60 weeks (37.00-39.40). The median AFI increased after the application from 4.00 (3.62-4.50) to 6.08 cm (4.90-7.03) (p < 0.001). The median PI of the fetal renal artery decreased from 2.30 (2.01-2.88) to 2.26 (1.68-2.71) (p = 0.01). The hourly fetal urine production did not increase. Changes were not significant in the PI of the umbilical artery, the middle cerebral artery, and the bilateral uterine arteries.

CONCLUSION

Short-term activation of pneumatic compression on maternal lower extremities could increase the AFI in women with isolated oligohydramnios.

The Use of Non-Invasive Continuous Blood Pressure Measuring (ClearSight®) during Central Neuraxial Anaesthesia for Caesarean Section—A Retrospective Validation Study

The close monitoring of blood pressure during a caesarean section performed under central neuraxial anaesthesia should be the standard of safe anaesthesia. As classical oscillometric and invasive blood pressure measuring have intrinsic disadvantages, we investigated a novel, non-invasive technique for continuous blood pressure measuring. Methods: In this monocentric, retrospective data analysis, the reliability of continuous non-invasive blood pressure measuring using ClearSight^® (Edwards Lifesciences Corporation) is validated in 31 women undergoing central neuraxial anaesthesia for caesarean section. In addition, patients and professionals evaluated ClearSight^® through questioning. Results: 139 measurements from 11 patients were included in the final analysis. Employing Bland–Altman analyses, we identified a bias of −10.8 mmHg for systolic, of −0.45 mmHg for diastolic and of +0.68 mmHg for mean arterial blood pressure measurements. Pooling all paired measurements resulted in a Pearson correlation coefficient of 0.7 for systolic, of 0.67 for diastolic and of 0.75 for mean arterial blood pressure. Compensating the interindividual differences in linear regressions of the paired measurements provided improved correlation coefficients of 0.73 for systolic, of 0.9 for diastolic and of 0.89 for mean arterial blood pressure measurements. Discussion: Diastolic and mean arterial blood pressure are within an acceptable range of deviation from the reference method, according to the Association for the Advancement of Medical Instrumentation (AAMI) in the patient collective under study. Both patients and professionals prefer ClearSight^® to oscillometric blood pressure measurement in regard of comfort and handling.

Perioperative hypotension: causes and remedies

Background

Arterial hypotension is common in patients during surgery and those admitted to the intensive care unit (ICU) postoperatively. Perioperative arterial hypotension reportedly significantly affects surgical patients’ outcomes. Blood pressure level is the most crucial factor that influences organ perfusion. Hypoperfusion and organ dysfunction are correlated based on their severity associated with hypotension. As several factors can cause intraoperative hypotension, anesthetists must promptly identify the etiology for appropriate treatment and revert the patient’s hemodynamic profile.

Objectives

This review discusses the concept of perioperative hypotension, identifies its effects in clinical situations, and provides remedies and techniques to predict and avoid its significant consequences.

Conclusions

The primary determinant of organ perfusion is blood pressure. On the other hand, profound hypotension is common in surgical patients and is connected to hypoperfusion and organ failure. Currently, hypotension is addressed once low blood pressure levels are recorded. Early detection of oncoming hypotension or its clinical prediction is of paramount importance in allowing the clinician to treat hypotension and reduce the incidence and length of hypotensive episodes promptly and aggressively.

Metoclopramide and Propofol to Prevent Nausea and Vomiting during Cesarean Section under Spinal Anesthesia: A Randomized, Placebo-Controlled, Double-Blind Trial

Background: Intra-operative nausea, vomiting and retching (NVR) are frequently associated with subarachnoid anesthesia (SA) in women undergoing cesarean section (CS). In this study performed in women undergoing CS under SA with a risk factor control strategy, we compared saline (placebo), propofol, metoclopramide and both drugs to prevent NVR. Methods: We recorded NVR events in 110 women undergoing CS who were randomized after umbilical cord clamping to receive saline (S; n = 27), metoclopramide 10 mg (M; n = 28), propofol 1 mg/kg/h (P; n = 27) or both drugs (PM; n = 28). Results: The proportion of women with intra-operative nausea was: S: 17/27 (63%); P: 15/27 (56%); M: 13/28 (46%); PM: 6/28 (21%) (p = 0.012, Cramér’s V = 0.31 (large effect). The proportion of women with intra-operative vomiting/retching was: S: 9/27 (33%); M: 7/27 (25%); P: 3/28 (11%); PM 2/28 (7%) (p = 0.049, Cramér’s V = 0.26 (medium effect). Post-hoc multiple comparisons revealed a significant reduction in NVR episodes and NRS scores between the PM group and control. Sedation scores did not differ among groups. Conclusion: In women undergoing CS under SA with a risk factor control strategy, combined propofol and metoclopramide reduce nausea and vomiting.

Interventions for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section

BACKGROUND

Nausea and vomiting are distressing symptoms which are experienced commonly during caesarean section under regional anaesthesia and in the postoperative period.  OBJECTIVES: To assess the efficacy of pharmacological and non-pharmacological interventions versus placebo or no intervention given prophylactically to prevent nausea and vomiting in women undergoing regional anaesthesia for caesarean section.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (16 April 2020), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of studies and conference abstracts, and excluded quasi-RCTs and cross-over studies.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Our primary outcomes are intraoperative and postoperative nausea and vomiting. Data entry was checked. Two review authors independently assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

Eighty-four studies (involving 10,990 women) met our inclusion criteria. Sixty-nine studies, involving 8928 women, contributed data. Most studies involved women undergoing elective caesarean section. Many studies were small with unclear risk of bias and sometimes few events. The overall certainty of the evidence assessed using GRADE was moderate to very low. 5-HT3 antagonists: We found intraoperative nausea may be reduced by 5-HT3 antagonists (average risk ratio (aRR) 0.55, 95% confidence interval (CI) 0.42 to 0.71, 12 studies, 1419 women, low-certainty evidence). There may be a reduction in intraoperative vomiting but the evidence is very uncertain (aRR 0.46, 95% CI 0.29 to 0.73, 11 studies, 1414 women, very low-certainty evidence). There is probably a reduction in postoperative nausea (aRR 0.40, 95% CI 0.30 to 0.54, 10 studies, 1340 women, moderate-certainty evidence), and these drugs may show a reduction in postoperative vomiting (aRR 0.47, 95% CI 0.31 to 0.69, 10 studies, 1450 women, low-certainty evidence). Dopamine antagonists: We found dopamine antagonists may reduce intraoperative nausea but the evidence is very uncertain (aRR 0.38, 95% CI 0.27 to 0.52, 15 studies, 1180 women, very low-certainty evidence). Dopamine antagonists may reduce intraoperative vomiting (aRR 0.41, 95% CI 0.28 to 0.60, 12 studies, 942 women, low-certainty evidence) and postoperative nausea (aRR 0.61, 95% CI 0.48 to 0.79, 7 studies, 601 women, low-certainty evidence). We are uncertain if dopamine antagonists reduce postoperative vomiting (aRR 0.63, 95% CI 0.44 to 0.92, 9 studies, 860 women, very low-certainty evidence). Corticosteroids (steroids): We are uncertain if intraoperative nausea is reduced by corticosteroids (aRR 0.56, 95% CI 0.37 to 0.83, 6 studies, 609 women, very low-certainty evidence) similarly for intraoperative vomiting (aRR 0.52, 95% CI 0.31 to 0.87, 6 studies, 609 women, very low-certainty evidence). Corticosteroids probably reduce postoperative nausea (aRR 0.59, 95% CI 0.49 to 0.73, 6 studies, 733 women, moderate-certainty evidence), and may reduce postoperative vomiting (aRR 0.68, 95% CI 0.49 to 0.95, 7 studies, 793 women, low-certainty evidence). Antihistamines: Antihistamines may have little to no effect on intraoperative nausea (RR 0.99, 95% CI 0.47 to 2.11, 1 study, 149 women, very low-certainty evidence) or intraoperative vomiting (no events in the one study of 149 women). Antihistamines may reduce postoperative nausea (aRR 0.44, 95% CI 0.30 to 0.64, 4 studies, 514 women, low-certainty evidence), however, we are uncertain whether antihistamines reduce postoperative vomiting (average RR 0.48, 95% CI 0.29 to 0.81, 3 studies, 333 women, very low-certainty evidence). Anticholinergics: Anticholinergics may reduce intraoperative nausea (aRR 0.67, 95% CI 0.51 to 0.87, 4 studies, 453 women, low-certainty evidence) but may have little to no effect on intraoperative vomiting (aRR 0.79, 95% CI 0.40 to 1.54, 4 studies; 453 women, very low-certainty evidence). No studies looked at anticholinergics in postoperative nausea, but they may reduce postoperative vomiting (aRR 0.55, 95% CI 0.41 to 0.74, 1 study, 161 women, low-certainty evidence). Sedatives: We found that sedatives probably reduce intraoperative nausea (aRR 0.65, 95% CI 0.51 to 0.82, 8 studies, 593 women, moderate-certainty evidence) and intraoperative vomiting (aRR 0.35, 95% CI 0.24 to 0.52, 8 studies, 593 women, moderate-certainty evidence). However, we are uncertain whether sedatives reduce postoperative nausea (aRR 0.25, 95% CI 0.09 to 0.71, 2 studies, 145 women, very low-certainty evidence) and they may reduce postoperative vomiting (aRR 0.09, 95% CI 0.03 to 0.28, 2 studies, 145 women, low-certainty evidence). Opioid antagonists: There were no studies assessing intraoperative nausea or vomiting. Opioid antagonists may result in little or no difference to the number of women having postoperative nausea (aRR 0.75, 95% CI 0.39 to 1.45, 1 study, 120 women, low-certainty evidence) or postoperative vomiting (aRR 1.25, 95% CI 0.35 to 4.43, 1 study, 120 women, low-certainty evidence). Acupressure: It is uncertain whether acupressure/acupuncture reduces intraoperative nausea (aRR 0.55, 95% CI 0.41 to 0.74, 9 studies, 1221 women, very low-certainty evidence). Acupressure may reduce intraoperative vomiting (aRR 0.52, 95% CI 0.33 to 0.80, 9 studies, 1221 women, low-certainty evidence) but it is uncertain whether it reduces postoperative nausea (aRR 0.46, 95% CI 0.27 to 0.75, 7 studies, 1069 women, very low-certainty evidence) or postoperative vomiting (aRR 0.52, 95% CI 0.34 to 0.79, 7 studies, 1069 women, very low-certainty evidence). Ginger: It is uncertain whether ginger makes any difference to the number of women having intraoperative nausea (aRR 0.66, 95% CI 0.36 to 1.21, 2 studies, 331 women, very low-certainty evidence), intraoperative vomiting (aRR 0.62, 95% CI 0.38 to 1.00, 2 studies, 331 women, very low-certainty evidence), postoperative nausea (aRR 0.63, 95% CI 0.22 to 1.77, 1 study, 92 women, very low-certainty evidence) and postoperative vomiting (aRR 0.20, 95% CI 0.02 to 1.65, 1 study, 92 women, very low-certainty evidence). Few studies assessed our secondary outcomes including adverse effects or women's views.

AUTHORS' CONCLUSIONS

This review indicates that 5-HT3 antagonists, dopamine antagonists, corticosteroids, sedatives and acupressure probably or possibly have efficacy in reducing nausea and vomiting in women undergoing regional anaesthesia for caesarean section. However the certainty of evidence varied widely and was generally low. Future research is needed to assess side effects of treatment, women's views and to compare the efficacy of combinations of different medications.

[Comments on the updated German S3 guidelines on intravascular volume therapy in adults]

The German S3 guidelines on intravascular volume therapy in adults were updated in September 2020. Based on updated evidence recommendations for the diagnosis of isotonic dehydration and for fluid therapy with crystalloids and colloids in peri-interventional and intensive care medicine were proposed.

Observation of hemodynamic parameters using a non-invasive cardiac output monitor system to identify predictive indicators for post-spinal anesthesia hypotension in parturients undergoing cesarean section

The administration of high-level spinal anesthesia for cesarean section may lead to significant hemodynamic changes. Bioreactance-based non-invasive cardiac output monitoring (NICOM^™) provides an accurate monitoring system for parturients under spinal anesthesia. The present study hypothesized that baseline hemodynamic parameters obtained via the NICOM^™ system could serve as predictive indicators for post-spinal anesthesia hypotension. Therefore, 80 full-term parturients with singleton pregnancies who underwent scheduled cesarean section were enrolled and allocated to either a supine position group or a 15˚ left tilt group. All parturients received standard pre-hydration with 750 ml of 0.9% saline. Baseline cardiac output index (CI), total peripheral resistance index (TPRI) and stroke volume (SV) were recorded using the NICOM^™ system. Subsequently, spinal anesthesia with 2.4 ml of 0.5% hyperbaric bupivacaine, 10 µg of fentanyl and 0.2 mg of morphine was administered. Receiver operating characteristic (ROC) curves and multivariate logistic regression were used to analyze the data. A total of 40 parturients (51.9%) developed hypotension. The areas under the ROC curves were 0.666, 0.594 and 0.622 for the CI, TPRI and SV, respectively. The optimal cut-off value of the CI in predicting hypotension was 3.68 l/min/m² (ROC, sensitivity=85.0%, specificity=48.6%). Furthermore, CI was considered as an independent factor for post-spinal anesthesia hypotension. In conclusion, the baseline CI obtained via the bioreactance-based NICOM^™ system may serve as a predictor of post-spinal anesthesia hypotension in parturients regardless of patient position.

Hemodynamic changes under spinal anesthesia after elastic wrapping or pneumatic compression of lower limbs in elective cesarean section: A randomized control trial

Background and Aims:

In spite of adequate fluid loading and left lateral tilt, parturients develop hypotension under spinal anesthesia during cesarean section. Elastic crepe bandage (CB) or pneumatic compression device (PCD) can be utilized to prevent the pooling of blood in lower limbs and thereby it may reduce the incidence of hypotension in these patients. This study was formulated to analyze the hemodynamic effects of leg wrapping with elastic CB and PCD in parturients undergoing for cesarean section under anesthesia.

Material and Methods:

Ninety term obstetric patients posted for elective cesarean section under spinal anesthesia were randomized into 3 groups: Group 1 (control), Group 2 (CB), and Group 3 (PCD). All the parturients had their legs wrapped with an elastic bandage and pneumatic sleeve applied over it. In Group 1 (Control), patients had their legs wrapped with CB loosely and pneumatic sleeve also applied was switched on. In Group 2, patients the CB was applied by stretching the bandage (15 cm width and 4 m stretched length). The PCD was not switched on in this group. In Group 3, the legs were wrapped with the CB loosely. The pneumatic sleeve was applied over the bandage, and the machine was switched on with a preset pressure of 40–50 mmHg after spinal anesthesia. Incidence of maternal hypotension and ephedrine requirement to maintain systolic blood pressure, neonatal Apgar score were recorded.

Results:

The incidence of hypotension was significantly lower in Group 2 and 3 than the control group. Similarly, the requirement of ephedrine was significantly high in control group compared to CB and PCD. The incidence of hypotension was lower in group CB than group PCD. Meantime to receive the first dose of ephedrine was significantly low in control (7.37 ± 4.94 min) as compared to CB (10 ± 2.8 min) and PCD (13.88 ± 9.23).

Conclusion:

Leg-wrapping with CB is cost-effective, non-invasive, non-pharmacological, and effective tool to reduce the incidence of hypotension after spinal anesthesia in a parturient.

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.

Hemodynamic changes after spinal anesthesia in preeclamptic patients undergoing cesarean section at a tertiary referral center in Ethiopia: a prospective cohort study

Background

Spinal anesthesia-induced maternal hypotension is the most frequent complication associated with maternal morbidity and mortality during Cesarean section. The aim of this study was to compare the incidence and magnitude of hemodynamic changes in preeclamptic and non-preeclamptic parturients undergone Cesarean section under spinal anesthesia.

Method

A prospective cohort study was conducted from 01 February to 28 May 2019 in preeclamptic and non-preeclamptic parturients. We hypothesized preeclamptic parturients are at high risk of spinal anesthesia induced hypotension than non preeclamptics. A total of 122 ASA II and ASA III parturients were recruited consecutively and assigned to two groups (81non-preeclamptics, and 41 preeclamptics). Parturients with cardiac disease, twin pregnancy, chronic hypertension, gestational hypertension, superimposed hypertension, renal disease, diabetes mellitus, coagulopathy (platelet count < 80 × 10⁹/L), active labor, eclampsia, abruptio placentae, placenta praevia, any adjuvant added with local anesthetics were excluded. The data analysis was done using SPSS version 22 statistical software. Student t test, MannWhitney U test and Fisher exact test were used to compare the data. All P values < 0.05 were considered statistically significant.

Result

The incidence of spinal anesthesia-induced hypotension was higher in non-preeclamptic parturients than preeclamptic parturients (55.6% vs. 34.1%, respectively) and the degree of blood pressure drop was significantly greater in the non-preeclamptic parturients compared to those with preeclampsia; As well intraoperative fluid consumption was significantly greater in the non-preeclamptics parturients compared to those with preeclamptics.

Conclusion

The incidence and magnitude of spinal anesthesia-induced hypotension in parturients undergone Cesarean section were less in preeclamptic parturients than in non-preeclamptic parturients.. Based on the data from this study we recommended spinal anesthesia for preeclamptic patients, unless there is a contra indication based on preeclampsia.

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.

Determination of the ED50 and ED95 of intravenous bolus of norepinephrine for the treatment of hypotension during spinal anesthesia for cesarean delivery

Norepinephrine is considered as a potential alternative for blood pressure stabilization during spinal anesthesia for cesarean delivery, as it maintains a better maternal heart rate and cardiac output compared with phenylephrine. However, its use as a bolus dose for hypotension treatment remains largely unexplored. Therefore, the present study investigated the ED₅₀ and ED₉₅ of norepinephrine as a bolus for maternal hypotension during cesarean delivery. In the present prospective trial, 42 patients were enrolled for elective delivery under spinal anesthesia. The dose of norepinephrine was decided by the up-and-down sequential allocation method (UDM) with an initial dose of 0.075 µg/kg and a 0.025 µg/kg increment. The 42 patients received a bolus of norepinephrine when systolic blood pressure fell to <80% of baseline. The ED₅₀ was calculated by the sequential method and the probit regression model. The ED₉₅ was then calculated using the probit regression model. The ED₅₀ of norepinephrine, which was determined by the UDM, was 0.067 µg/kg (95% CI, 0.056–0.081). The probit regression model calculated an ED₅₀ of 0.072 µg/kg (95% CI, 0.056–0.088) and an ED₉₅ of 0.121 µg/kg (95% CI, 0.1–0.207). In summary, the present results suggested the ED₅₀ of a bolus norepinephrine for preventing hypotension in elective CD is 0.067 µg/kg (95% CI, 0.056–0.081), with an ED₉₅ of 0.121 µg/kg (95% CI, 0.1–0.207).

Combined spinal-epidural versus spinal anaesthesia for caesarean section

BACKGROUND

Single-shot spinal anaesthesia (SSS) and combined spinal-epidural (CSE) anaesthesia are both commonly used for caesarean section anaesthesia. Spinals offer technical simplicity and rapid onset of nerve blockade which can be associated with hypotension. CSE anaesthesia allows for more gradual onset and also prolongation of the anaesthesia through use of a catheter.

OBJECTIVES

To compare the effectiveness and adverse effects of CSE anaesthesia to single-shot spinal anaesthesia for caesarean section.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP), and reference lists of retrieved studies (search date: 8 August 2019).

SELECTION CRITERIA

We considered all published randomised controlled trials (RCTs) involving a comparison of CSE anaesthesia with single-shot spinal anaesthesia for caesarean section. We further subgrouped spinal anaesthesia as either high-dose (10 or more mg bupivacaine), or low-dose (less than 10 mg bupivacaine).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risks of bias, extracted data and checked them for accuracy. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified 18 trials including 1272 women, but almost all comparisons for individual outcomes involved relatively small numbers of women. Two trials did not report on this review's outcomes and therefore contribute no data towards this review. Trials were conducted in national or university hospitals in Australia (1), Croatia (1), India (1), Italy (1), Singapore (3), South Korea (4), Spain (1), Sweden (1), Turkey (2), UK (1), USA (2). The trials were at a moderate risk of bias overall.CSE versus high-dose spinal anaesthesiaThere may be little or no difference between the CSE and high-dose spinal groups for the number of women requiring a repeat regional block or general anaesthetic as a result of failure to establish adequate initial blockade (risk ratio (RR) 0.32, 95% confidence interval (CI) 0.05 to 1.97; 7 studies, 341 women; low-quality evidence). We are uncertain whether having CSE or spinal makes any difference in the number of women requiring supplemental intra-operative analgesia at any time after CSE or spinal anaesthetic insertion (average RR 1.25, 95% CI 0.19 to 8.43; 7 studies, 390 women; very low-quality evidence), or the number of women requiring intra-operative conversion to general anaesthesia (RR 1.00, 95% CI 0.07 to 14.95; 7 studies, 388 women; very low-quality evidence). We are also uncertain about the results for the number of women who were satisfied with anaesthesia, regardless of whether they received CSE or high-dose spinal (RR 0.93 95% CI 0.73 to 1.19; 2 studies, 72 women; very low-quality evidence). More women in the CSE group (13/21) experienced intra-operative nausea or vomiting requiring treatment than in the high-dose spinal group (6/21). There were 11 cases of post-dural puncture headache (5/56 with CSE versus 6/57 with SSS; 3 trials, 113 women) with no clear difference between groups. There was also no clear difference in intra-operative hypotension requiring treatment (46/86 with CSE versus 41/76 with SSS; 4 trials, 162 women). There were no babies with Apgar score less than seven at five minutes (4 trials, 182 babies).CSE versus low-dose spinal anaesthesiaThere may be little or no difference between the CSE and low-dose spinal groups for the number of women requiring a repeat regional block or general anaesthetic as a result of failure to establish adequate initial blockade (RR 4.81, 95% CI 0.24 to 97.90; 3 studies, 224 women; low-quality evidence). Similarly, there is probably little difference in the number of women requiring supplemental intra-operative analgesia at any time after CSE or low-dose spinal anaesthetic insertion (RR 1.75, 95% CI 0.78 to 3.92; 4 studies, 298 women; moderate-quality evidence). We are uncertain about the effect of CSE or low-dose spinal on the need for intra-operative conversion to general anaesthesia, because this was not required by any of the 222 women in the three trials (low-quality evidence). None of the studies examined whether women were satisfied with their anaesthesia.The mean time to effective anaesthesia was faster in women who received low-dose spinal compared to CSE, although it is unlikely that the magnitude of this difference is clinically meaningful (standardised mean difference (SMD) 0.85 minutes, 95% CI 0.52 to 1.18 minutes; 2 studies, 160 women).CSE appeared to reduce the incidence of intra-operative hypotension requiring treatment compared with low-dose spinal (average RR 0.59, 95% CI 0.38 to 0.93; 4 studies, 336 women). Similar numbers of women between the CSE and low-dose spinal groups experienced intra-operative nausea or vomiting requiring treatment (3/50 with CSE versus 6/50 with SSS; 1 study, 100 women), and there were no cases of post-dural puncture headache (1 study, 138 women). No infants in either group had an Apgar score of less than seven at five minutes (1 study; 60 babies).

AUTHORS' CONCLUSIONS

In this review, the number of studies and participants for most of our analyses were small and some of the included trials had design limitations. There was some suggestion that, compared to spinal anaesthesia, CSE could be associated with a reduction in the number of women with intra-operative hypotension, but an increase in intra-operative nausea and vomiting requiring treatment. One small study found that low-dose spinal resulted in a faster time to effective anaesthesia compared to CSE. However, these results are based on limited data and the difference is unlikely to be clinically meaningful. Consequently, there is currently insufficient evidence in support of one technique over the other and more evidence is needed in order to further evaluate the relative effectiveness and safety of CSE and spinal anaesthesia for caesarean section.More high-quality, sufficiently-powered studies in this area are needed. Such studies could consider using the outcomes listed in this review and should also consider reporting economic aspects of the different methods under investigation.

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.

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.

Ondansetron 8 mg and 4 mg with normal saline against post-operative headache and nausea/vomiting after spinal anesthesia: a randomized double-blind trial

The study aims to evaluate the efficacy of ondansetron in preventing post-spinal headache, considering the high prevalence of the headache in pregnant women and the common use of the adjuvants for prophylaxis against post-operative nausea and vomiting (PONV). This double-blind clinical trial included the 195 patients who were referred to Taleghani Hospital (in Arak, Iran) for cesarean section (C/S) under spinal anesthesia, and then the subjects were assigned to three equally sized groups using block randomization. Participants in the first, second, and control groups received 8 mg, 4 mg of ondansetron, and normal saline, respectively, 5 minutes before surgery. A final volume of 5 cc was prepared by adding normal saline. Participants were examined for headache one week after surgery, and then data analysis was performed using SPSS 20. The incidence of post-spinal headache was significantly higher in the placebo group than in the ondansetron 8-mg and 4-mg groups at 24 hours after surgery (P < 0.010). But, no significant difference was observed between two ondansetron groups (P ≤ 0.05). The overall incidence of the headache was generally lower in ondansetron 8-mg (26.66% vs. 33.68.05%) and 31.66% in ondansetron 4-mg (P < 0.001). Moreover, the PONV incidence was significantly higher in the placebo group than in the other two groups at 24 hours (P < 0.001). The hemodynamic variables were same in three groups. The ondansetron 8-mg dose can be effective to prevent headache after spinal anesthesia for C/S. Moreover, the ondansetron 8-mg and ondansetron 4-mg have same effect in control of PONV after spinal anesthesia for C/S.

Angiotensin in Critical Care

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2018. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2018 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901 .

[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.