Influence of the timing of administration of crystalloid on maternal hypotension during spinal anesthesia for cesarean delivery: preload versus coload

Point of care transthoracic echocardiography for the prediction of post - spinal anesthesia hypotension in elderly patients with cardiac diseases and left ventricular dysfunction : Inferior vena cava and post-spinal anesthesia hypotension in elderly patients

In elderly patients with cardiac diseases, changes in cardiovascular physiology diminish cardiovascular reserve and predispose to hemodynamic instability after spinal anesthesia; hence, such patients could be at risk of postoperative complications. Additionally, transthoracic echocardiography (TTE) is used in clinical practice to evaluate cardiovascular hemodynamics. Therefore, we hypothesized that echocardiographic measurements could display significant diagnostic power in the prediction of post - spinal anesthesia hypotension in elderly patients with cardiac diseases and reduced left ventricular ejection fraction (LV-EF). Therefore, sixty-one elderly orthopedic-trauma patients were recruited. Prior to spinal anesthesia a TTE examination was performed. The LV-EF, the stroke volume index (SVI), the peripheral vascular resistance (PVR), the LV filling pressures (E/Em ratio), the right ventricular function [tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic velocity (TASV) and fractional area change (FAC)], as well as inferior vena cava (IVC) measurements, such as IVCCI (collapsibility index of the IVC) and dIVCmax (maximum diameter of IVC)-to-IVCCI ratio were assessed. Twenty-six out of sixty-one patients manifested hypotension. Preoperative dIVCmax-to-IVCCI ratio demonstrated the greatest performance amongst echocardiographic indices in predicting post - spinal anesthesia hypotension. The dIVCmax-to-IVCCI ratio < 48 had significantly higher diagnostic power than IVCCI > 0.28, FAC > 42, E/Em ratio < 9 and SVI < 32 (receiver operator characteristic curve analysis). The gray zone for the dIVCmax-to-IVCCI ratio (40-49) showed the lowest number of inconclusive measurements among echocardiographic variables. The preoperative dIVCmax-to-IVCCI ratio could be a reliable echocardiographic index to predict post - spinal anesthesia hypotension in elderly patients with left ventricular dysfunction.

Comparison of the effects of general and spinal anesthesia for cesarean delivery on maternal and fetal outcomes: A retrospective analysis of data

OBJECTIVE

General or single-shut spinal anesthesia (SA) is applied for cesarean section and both methods of anesthesia have different effects on the mother and newborn. This retrospective study, in which 1-year data were analyzed, was aimed to examine the effects of general or SA on maternal and neonatal outcomes.

METHODS

Anesthesia technique, mother's age, gestational age, number of pregnancies, previous cesarean delivery number, maternal complications, and indications for cesarean delivery were analyzed in 883 cesarean deliveries. In addition, weight and Apgar scores of newborn and umbilical cord blood gas values were examined.

RESULTS

Neonatal intensive care need was higher in the general anesthesia (GA) group, Apgar scores were higher in the SA group, but neonatal mortality was similar. The umbilical cord Ph and lactate were lower; PCO2 values were higher in the GA group. Neonatal weight, mother's age, gestational age, and Apgar scores were predictive for neonatal mortality, but anesthesia technique was not.

CONCLUSION

While umbilical cord blood gas values were less affected and the need for neonatal intensive care was lower with SA, we believe that both anesthesia methods can be used safely for mother and neonatal in cesarean anesthesia considering maternal and neonatal morbidity and mortality.

Preliminary study on fluid bolus administration for prevention of spinal hypotension in dogs undergoing elective cesarean section

Introduction

This study aimed to investigate the effect of fluid bolus administration during epidural anesthesia (coload) in female dogs scheduled for elective cesarean section (CS). Hypotension is one of the most common complications of epidural (EA) and spinal (SA) analgesia, and in the case of cesarean section, it may pose a significant risk for placental perfusion and subsequent fetal vitality and puppy survival.

Methods

Pregnant bitches scheduled for elective CS underwent EA with (treatment group) or without (control group) intravenous fluid bolus administration. The following parameters were measured and compared between both groups: HR, RR, etCO₂, SpO₂, systolic, diastolic and mean arterial blood pressure were measured at three time points (T1: before surgery, T2: after the last puppy removal, and T3: end of surgery) in dams; vitality (Apgar score at 0, 5, and 20 min) and umbilical cord blood parameters (pH, pCO2, HCO3, base excess, lactate and glucose) in newborns.

Results

The results indicated that crystalloid coloading increased maternal systolic, diastolic, and mean blood pressure (treatment vs. control group, 101.46 ± 9.18, 48.01 ± 13.47, and 67.07 ± 13.15 mmHg vs. 80.68 ± 7.29, 36.52 ± 8.75, and 180 52.30 ± 7.77, p < 0.05) with significantly fewer episodes of hypotension. Additionally, puppies in the treatment group received higher scores in the 5-min (7.91 ± 1.67 vs. 6.74 ± 2.20) and 20-min (9.38 ± 0.87 vs. 8.39 ± 2.50) assessments without the favorable effect on umbilical blood gas parameters.

Discussion

Based on the obtained results, it can be stated that crystalloid coload offers an effective option in cases of hypotension during cesarean section, with clear benefits for both mothers and newborns.

Effect of Crystalloid or Colloid Fluid Loading and Vasopressor Pre-Treatment on the Timing of Hypotension in Cesarean Section with Subarachnoid Block

BACKGROUND: Cesarean section (C-section) is the most frequently performed surgery in obstetrics, generally using subarachnoid block (SAB) or epidural block for anesthesia. The previous studies have shown the effectiveness of fluid loading and vasopressor pretreatment in preventing maternal hypotension (decreased blood pressure), the most common side effect of SAB. However, the timing of hypotension in response to these treatments has not been analyzed. AIM: This study therefore aimed to compare the effects of crystalloid or colloid fluid loading and vasopressor pre-treatment on the timing of hypotension in cases of C-section under SAB anesthesia. METHODS: The study was a single-blind randomized controlled clinical trial with three treatment groups: Group I, 10 mL/kgBW crystalloid solution (Ringer’s lactate) loading 10 min before SAB; Group II, 5 mL/kgBW colloid fluid (gelatin) loading 10 min before SAB; and Group III, pretreatment with 0.1 mg/kgBW vasopressor (ephedrine) intravenous bolus just before SAB. RESULTS: Significant differences in mean blood pressure between groups were observed between the second and 8th min (p < 0.05). Hypotension was observed in the crystalloid group within the first 5 min, while average blood pressure was relatively stable all groups after the first 10 min. In addition, hypotension occurred more frequently in the crystalloid group (nine subjects, 45%), compared with the colloid and vasopressor groups (two subjects per group, 10%; p < 0.05). CONCLUSION: Hypotension occurred more rapidly and more frequently when crystalloid loading was utilized, compared with colloid loading or vasopressor pretreatment. Administration of colloid fluid loading and vasopressor pretreatment has been shown to prevent hypotension in SAB anesthesia.

Fluid loading therapy to prevent spinal hypotension in women undergoing elective caesarean section: Network meta-analysis, trial sequential analysis and meta-regression

BACKGROUND

Fluid loading is one of the recognised measures to prevent hypotension due to spinal anaesthesia in women scheduled for a caesarean section.

OBJECTIVE

We aimed to evaluate the current evidence on fluid loading in the prevention of spinal anaesthesia-induced hypotension.

DESIGN

Systematic review and network meta-analysis with trial sequential analysis and meta-regression.

DATA SOURCES

Medline, Epub, Embase.com (Embase and Medline), Cochrane Central, Web of Science and Google Scholar were used.

ELIGIBILITY CRITERIA

Only randomised controlled trials were used. Patients included women undergoing elective caesarean section who received either crystalloid or colloid fluid therapy as a preload or coload. The comparator was a combination of either a different fluid or time of infusion.

RESULTS

A total of 49 studies (4317 patients) were included. Network meta-analysis concluded that colloid coload and preload offered the highest chance of success (97 and 67%, respectively). Conventional meta-analysis showed that crystalloid preload is associated with a significantly higher incidence of maternal hypotension than colloid preload: risk ratio 1.48 (95% CI 1.29 to 1.69, P < 0.0001, I² = 60%). However, this result was not supported by Trial Sequential Analysis. There was a significant dose–response effect for crystalloid volume preload (regression coefficient = −0.073), which was not present in the analysis of only double-blind studies. There was no dose–response effect for the other fluid regimes.

CONCLUSION

Unlike previous meta-analysies, we found a lack of data obviating an evidence-based recommendation. In most studies, vasopressors were not given prophylactically as is recommended. Studies on the best fluid regimen in combination with prophylactic vasopressors are needed. Due to official european usage restrictions on the most studied colloid (HES), we recommend crystalloid coload as the most appropriate fluid regimen.

TRIAL REGISTRATION

CRD42018099347.

Predictability of preoperative carotid artery-corrected flow time for hypotension after spinal anaesthesia in patients undergoing caesarean section: A prospective observational study

BACKGROUND

Spinal anaesthesia-induced hypotension is frequently reported in patients undergoing caesarean section. Mechanistically, sympathetic blockade reduces the systemic vascular resistance and the left ventricular preload, causing hypotension, which is augmented by aortocaval compression. The corrected blood flow time (FTc) is affected by the preload and is inversely related to the afterload.

OBJECTIVE

We hypothesised that the preanaesthetic carotid artery FTc could predict hypotension after induction in patients undergoing a caesarean section with spinal anaesthesia.

DESIGN

A prospective observational study.

SETTING

A tertiary referral centre in South Korea from September 2018 to November 2019.

PARTICIPANTS

Thirty-eight parturients scheduled for elective caesarean section under spinal anaesthesia.

INTERVENTIONS

Using carotid ultrasonography, FTc was measured twice prior to inducing spinal anaesthesia. FTc was calculated using both Bazett's (B) and Wodey's (W) formulae. Hypotension was defined as an SBP decrease to less than 80 mmHg, or less than 75% of baseline, or if symptoms consistent with hypotension occurred from the time of injection of the spinal anaesthetic until delivery.

MAIN OUTCOME MEASURES

The primary endpoint was to determine the predictive value of preanaesthetic FTc for postspinal hypotension during caesarean delivery.

RESULTS

Among the 35 patients who completed this study, hypotension occurred in 21 (60%). The areas under the receiver-operating characteristic curves for FTc (B) and FTc (W) were 0.905 [95% confidence interval (CI), 0.757 to 0.978, P < 0.001] and 0.922 (95% CI, 0.779 to 0.985, P < 0.001), respectively. The optimal cut-off values for predicting hypotension were 346.4 and 326.9 ms, respectively. The grey zone for FTc (B) and FTc (W) included 40 and 14% of the patients, respectively.

CONCLUSION

Preanaesthetic carotid artery FTc was a reliable indicator of postspinal hypotension in parturients. Considering the grey zone, Wodey's formula is better than Bazett's formula.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03631329.

[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.

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.

Effects of isothermic crystalloid coload on maternal hypotension and fetal outcomes during spinal anesthesia for cesarean section: A randomized controlled trial

OBJECTIVE

Spinal anesthesia induced hypotension (SAIH) is a common occurrence during spinal anesthesia for cesarean section resulting in perturbing effects on maternal and fetal outcomes. Previous studies conducted to attenuate SAIH focused on the timing of intravenous fluid infusion and demonstrated the superiority of coload strategy on traditional preload strategy but neither of them focused on the effect of the temperature of crystalloid infused on SAIH and fetal outcomes. The current study aimed to assess the effect of the temperature of the crystalloid infused with coload strategy on the incidence of SAIH and fetal outcomes.

MATERIALS AND METHODS

Seventy-six parturients were enrolled into the study and data of 60 parturients were analyzed. Patients were randomly assigned to receive crystalloid coload at room temperature (Group RT, n = 30) or warmed at 37 °C (Group W, n = 30). The incidence of hypotension, cumulative hypotension episodes, heart rate, core body temperature, ephedrine dose, and fetal outcomes were recorded.

RESULTS

There was no significant difference in the incidence of maternal hypotension, cumulative hypotension episodes, and ephedrine dose (p = 0,625, p = 0,871, p = 0,460 respectively). Umbilical arterial pH and fetal Apgar scores at first and fifth minutes were higher in Group W than in Group RT (p = 0.013, p = 0.006 and p = 0.045 respectively). One fetus in Group RT but none in Group W had umbilical arterial pH lower than seven. Fetal birth weight and rectal temperature measurements were comparable in both groups (p = 0.639 and p = 0.675 respectively). Demographic data, patient characteristics, and surgery data were comparable between groups.

CONCLUSIONS

Isothermic crystalloid coload strategy results in higher umbilical pH values and Apgar scores in parturients scheduled for cesarean section under spinal anesthesia.

A Comparison Between the Effects of Preloading with Ringer's Solution and Voluven on Hemodynamic Changes in Patients Undergoing Elective Cesarean Section Under Spinal Anesthesia

Introduction

The most common complications after spinal anesthesia for Cesarean section is hypotension. Administration of intravenous crystalloid or colloid fluid before the induction of anesthesia is a way to prevent it.

Aim

The aim of this study was to compare the effects of preloading with ringer's solution and Voluven on hemodynamic changes in patients underwent elective Caesarean section under spinal anesthesia.

Methods

This study was conducted on 70 pregnant women. They were randomly divided into two groups of 35. Group I received 10 ml/kg Ringer's solution (R group) and group II received 10 ml/kg Voluven (V group) over 15 min before spinal anesthesia. Mean SBP, DBP, MAP, HR, SPO2, mean Apgar of newborn at 1 and 5 minutes after birth, mean blood pH and analysis of umbilical venous blood gases of newborns, prevalence of nausea and vomiting, and the rate of shivering and its severity were recorded in the both groups.

Results

Blood pH and analysis of blood gases and Apgar of newborn at 1 and 5 minutes after birth were similar in both groups. Shivering did not differ significantly between the two groups. Level of anesthesia and the incidence of nausea and vomiting in the R group were significantly higher than those in the V group (P=0.041 and P=0.029, respectively).

Conclusion

The administration of both crystalloid and colloid fluids were effective in preventing the hypotension, although the use of Voluven was preferred to Ringer with respect to the level of the blockade and the incidence of nausea and vomiting.

Prevention of hypotension after spinal anaesthesia for caesarean section: a systematic review and network meta-analysis of randomised controlled trials

Spinal anaesthesia for caesarean section commonly causes maternal hypotension. This systematic review and network meta-analysis compared methods to prevent hypotension in women receiving spinal anaesthesia for caesarean section. We selected randomised controlled trials that compared an intervention to prevent hypotension with another intervention or inactive control by searching MEDLINE and Embase, Web of Science to December 2018. There was no language restriction. Two reviewers extracted data on trial characteristics, methods and outcomes. We assessed risk of bias for individual trials (Cochrane tool) and quality of evidence (GRADE checklist). We assessed 109 trials (8561 women) and 12 different methods that resulted in 30 direct comparisons. Methods ranked by OR (95%CI) from most effective to least effective were: metaraminol 0.11 (0.04-0.26); norepinephrine 0.13 (0.06-0.28); phenylephrine 0.18 (0.11-0.29); leg compression 0.25 (0.14-0.43); ephedrine 0.28 (0.18-0.43); colloid given before induction of anaesthesia 0.38 (0.24-0.61); angiotensin 2, 0.12 (0.02-0.75); colloid given after induction of anaesthesia 0.52 (0.30-0.90); mephentermine 0.09 (0.01-1.30); crystalloid given after induction of anaesthesia 0.78 (0.46-1.31); and crystalloid given before induction of anaesthesia 1.16 (0.76-1.79). Phenylephrine caused maternal bradycardia compared with control, OR (95%CI) 0.23 (0.07-0.79). Ephedrine lowered umbilical artery pH more than phenylephrine, standardised mean difference (95%CI) 0.78 (0.47-1.49). We conclude that vasopressors should be given to healthy women to prevent hypotension during caesarean section with spinal anaesthesia.

Spinal anesthesia-induced hypotension is caused by a decrease in stroke volume in elderly patients

Background

Hypotension is common during spinal anesthesia (SA) and is caused by a decrease in systemic vascular resistance (SVR) and/or cardiac output (CO). The effect of the dose of bupivacaine administered intrathecally on the changes in CO in elderly patients is largely unknown. This study investigated the hemodynamic effect of SA in elderly patients by studying the effect of two different dosages of intrathecal bupivacaine.

Methods

This prospective cohort study included 64 patients aged >65 years scheduled for procedures under SA; the patients received either 15 mg bupivacaine (the medium dose [MD] group) or 10 mg bupivacaine and 5 μg sufentanil (the low dose [LD] group). Blood pressure and CO were monitored throughout the procedure using Nexfin™, a noninvasive continuous monitoring device using a finger cuff.

Results

Thirty-three patients received MD and 31 received LD and there was no mean difference in baseline hemodynamics between the groups. On an average, the CO decreased 11.6% in the MD group and 10.0 % in the LD group. There was no significant change in SVR. Incidence of a clinically relevant decrease in stroke volume (SV) (>15% from baseline) was 67% in the MD and 45% in the LD groups (P<0.05).

Conclusion

CO and blood pressure decreased significantly after the onset of SA in elderly patients. This is mainly caused by a decrease in SV and not by a decrease in SVR. There was no difference in CO and blood pressure change between dosages of 10 or 15 mg bupivacaine.

Role of IVC collapsibility index to predict post spinal hypotension in pregnant women undergoing caesarean section. An observational trial

Background:

Postspinal anesthesia hypotension (PSH) in pregnant women is common and may lead to poor maternal and fetal outcome. Fluid loading in pregnant women before spinal anesthesia to prevent hypotension is of limited ability. We hypothesized that those women who are hypovolemic before spinal anesthesia may be at risk of PSH and inferior vena cava collapsibility index (IVCCI) will be able to identify hypovolemic parturients.

Methods:

In this prospective observational study, n = 45 women undergoing elective lower segment cesarean section with singleton pregnancy were recruited and IVCCI in left lateral tilt (with wedge) and supine position (without wedge) were noted by M-mode ultrasound (USG) before spinal anesthesia. After spinal anesthesia, changes in blood pressure were noted till 15 min after spinal anesthesia.

Results:

USG measurements were obtained in 40 patients and 23 of 40 patients (57.5%) had at least one episode of hypotension. Area under the ROC curve of IVCCI with wedge to predict PSH was 0.46 (95% CI 0.27, 0.64) and best cut-of value was 25.64 with a sensitivity and specificity of 60.9% and 35.5%, respectively. Area under the ROC curve of IVCCI without wedge to predict PSH was 0.38 (95% CI 0.19, 0.56) and best cut-of value was 20.4 with a sensitivity and specificity of 69.6% and 23.5%, respectively.

Conclusion:

We conclude that IVCCI is not a predictor of PSH in pregnant women undergoing elective cesarean section.

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 ).

Crystalloid Coload Reduced the Incidence of Hypotension in Spinal Anesthesia for Cesarean Delivery, When Compared to Crystalloid Preload: A Meta-Analysis

Objective

To determine whether crystalloid infusion just after intrathecal injection (coload) would be better than infusion before anesthesia (preload) for hypotension prophylaxis in spinal anesthesia for cesarean delivery.

Methods

We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and other databases for randomized controlled trials comparing coload of crystalloid with preload in parturients receiving spinal anesthesia for cesarean delivery. Primary outcome was intraoperative incidence of hypotension. Other outcomes were intraoperative need for vasopressors, hemodynamic variables, neonatal outcomes (umbilical artery pH and Apgar scores), and the incidence of maternal nausea and vomiting. We used RevMan 5.2 and STATA 12.0 for the data analyses.

Results

Ten studies with 824 cases were included. The incidence of hypotension was significantly higher in the preload group compared with the coload group (57.8% versus 47.1%, odds ratio [OR] = 1.62, 95% confidence interval [CI] = 1.11–2.37, and P = 0.01). More patients needed intraoperative vasopressors (OR = 1.71, 95% CI = 1.07–2.04, and P = 0.02) when receiving crystalloid preload. In addition, the incidence of nausea and vomiting was higher in the preload group (OR = 3.40, 95% CI = 1.88–6.16, and P < 0.0001). There were no differences in neonatal outcomes between the groups.

Conclusions

For parturients receiving crystalloid loading in spinal anesthesia for cesarean delivery, coload strategy is superior to preload for the prevention of maternal hypotension.

Does prophylactic ondansetron reduce norepinephrine consumption in patients undergoing cesarean section with spinal anesthesia?

PURPOSE

Spinal anesthesia-induced hypotension (SAIH) during cesarean delivery is not rare and frequently leads to materno-fetal discrepancy and collapse. More recently, norepinephrine has been proposed for the prevention and treatment of SAIH with fewer tendencies to decrease heart rate and cardiac output. Ondansetron has been reported to reduce the incidence of SAIH in patients undergoing cesarean section. The aim of the present study was to assess the effect of prophylactic ondansetron on the incidence of SAIH, norepinephrine consumption, and adverse effects.

METHODS

We recruited 108 parturients with uncomplicated pregnancies undergoing elective cesarean delivery under spinal anesthesia. The parturients were divided into two groups randomly. The first group (n = 54) received 8 mg ondansetron IV (group O) and the second group (n = 54) received the same volume (4 ml) of saline (group S), 5 min before spinal anesthesia. The incidence of hypotension, cumulative episodes of hypotension, total norepinephrine consumption, and adverse effects were recorded.

RESULTS

There was no significant difference between the two groups in demographic data, parturient characteristics, and duration of surgery. No significant difference was found in the incidence of hypotension in the saline and ondansetron groups (p = 0.767). However, the cumulative episodes of hypotension and norepinephrine consumptions were significantly greater in group S than in group O (p = 0.009) (p = 0.009). There was also no significant difference in the incidence of adverse effects between the two groups.

CONCLUSION

Eight milligrams of intravenous ondansetron given 5 min before spinal anesthesia attenuated but did not prevent spinal anesthesia-induced hypotension in parturients undergoing elective cesarean delivery.

The Effects of Hydroxyethyl Starch 6% and Crystalloid on Volume Preloading Changes following Spinal Anesthesia

BACKGROUND

Hypotension is one of the most common complications after spinal anesthesia for cesarean delivery. Normally, preloading with fluids, especially crystalloids, is used to prevention of hypotension.

METHODS

In the present randomized clinical trial study, 120 parturients presenting for elective cesarean section with the American Society of Anesthesiologists Class I and II received either 15 cc normal saline or 7 cc/kg hydroxyethyl starch 6% (Voluven) fluid. Information regarding to systolic, diastolic, mean arterial pressure, and heart rate, incidence of hypotension, adverse effects, the total dose of atropine, and ephedrine were recorded in before and 3, 6, 9, 15, and 20 min after spinal anesthesia. Furthermore, Apgar score of newborn at the 1st and 5th min after birth was recorded.

RESULTS

There was no significant difference in mean arterial pressure at different stages such as: Exactly after spinal and 3, 6, 15, and 20 min after spinal anesthesia between two groups (P > 0.05). Total dose of ephedrine and atropine were similar between groups (P > 0.05), respectively. There was no significant difference in Apgar score at the 1st and 5th min after birth between two groups. There were not any adverse effects of drugs in two groups.

CONCLUSIONS

The results of this study show that hydroxyethyl starch 6% compared to normal saline are similar to prevent hypotension during spinal anesthesia for cesarean delivery.

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.

Practice Guidelines for Obstetric Anesthesia

The American Society of Anesthesiologists Committee on Standards and Practice Parameters and the Task Force on Obstetric Anesthesia and the Society for Obstetric Anesthesia and Perinatology present an updated report of the Practice Guidelines for Obstetric Anesthesia.

Supplemental Digital Content is available in the text.

Combined use of hyperbaric and hypobaric ropivacaine significantly improves hemodynamic characteristics in spinal anesthesia for caesarean section: a prospective, double-blind, randomized, controlled study

PURPOSE

To observe the hemodynamic changes of parturients in the combined use of hyperbaric (4 mg) and hypobaric (6 mg) ropivacaine during spinal anesthesia for caesarean section in this randomized double-blind study.

METHODS

Parturients (n = 136) undergoing elective cesarean delivery were randomly and equally allocated to receive either combined hyperbaric and hypobaric ropivacaine (Group A) or hyperbaric ropivacaine (Group B). Outcome measures were: hemodynamic characteristics, maximum height of sensory block, time to achieve T8 sensory blockade level, incidence of complications, Apgar scores at 1 and 5 min, and neonatal blood gas analysis.

RESULTS

Group A had a lower level of sensory blockade (T6 [T6-T7]) and longer time to achieve T8 sensory blockade level (8 ± 1.3 min) than did patients in Group B (T3 [T2-T4] and 5 ± 1.0 min, respectively; P < 0.001, both). The incidence rates for hypotension, nausea, and vomiting were significantly lower in Group A (13%, 10%, and 3%, respectively) than Group B (66%, 31%, and 13%; P < 0.001, P = 0.003, P = 0.028).

CONCLUSIONS

Combined use of hyperbaric (4 mg) and hypobaric (6 mg) ropivacaine significantly decreased the incidences of hypotension and complications in spinal anesthesia for caesarean section by extending induction time and decreasing the level of sensory blockade.

TRIAL REGISTRATION

Chinese Clinical Trial Register ChiCTR-TRC-13004622.

Comparison of maternal and fetal outcomes among patients undergoing cesarean section under general and spinal anesthesia: a randomized clinical trial

CONTEXT AND OBJECTIVE

As the rates of cesarean births have increased, the type of cesarean anesthesia has gained importance. Here, we aimed to compare the effects of general and spinal anesthesia on maternal and fetal outcomes in term singleton cases undergoing elective cesarean section.

DESIGN AND SETTING

Prospective randomized controlled clinical trial in a tertiary-level public hospital.

METHODS

Our study was conducted on 100 patients who underwent cesarean section due to elective indications. The patients were randomly divided into general anesthesia (n = 50) and spinal anesthesia (n = 50) groups. The maternal pre and postoperative hematological results, intra and postoperative hemodynamic parameters and perinatal results were compared between the groups.

RESULTS

Mean bowel sounds (P = 0.036) and gas discharge time (P = 0.049) were significantly greater and 24th hour hemoglobin difference values (P = 0.001) were higher in the general anesthesia group. The mean hematocrit and hemoglobin values at the 24th hour (P = 0.004 and P < 0.001, respectively), urine volume at the first postoperative hour (P < 0.001) and median Apgar score at the first minute (P < 0.0005) were significantly higher, and the time that elapsed until the first requirement for analgesia was significantly longer (P = 0.042), in the spinal anesthesia group.

CONCLUSION

In elective cases, spinal anesthesia is superior to general anesthesia in terms of postoperative comfort. In pregnancies with a risk of fetal distress, it would be appropriate to prefer spinal anesthesia by taking the first minute Apgar score into account.

Update on volume therapy in obstetrics

Symptomatic hypotension (maternal nausea, vomiting, dizziness and dyspnoea) during spinal anaesthesia for caesarean delivery remains a prevalent clinical problem. Severe and sustained hypotension can lead to impairment of uteroplacental perfusion, foetal hypoxia, acidosis, neonatal depression and further adverse maternal outcomes of unconsciousness, pulmonary aspiration, apnoea and cardiac arrest. Mechanical methods aimed at countering the effects of aortocaval compression do not reliably prevent maternal hypotension. Intravenous crystalloid preloading (given prior to administration of spinal anaesthesia) has poor efficacy, and focus has changed towards decreased use of crystalloid preload and ephedrine, to increased use of coload (given at the time of spinal administration) with colloids or crystalloids, and early use of phenylephrine. The recent multicentre, randomised, double-blinded CAESAR trial demonstrated the efficacy of a mixed 500 ml 6% hydroxyethyl starch (HES) 130/0.4 + 500 ml Ringer's lactate (RL) preload in significantly reducing hypotension, compared to a 1-l RL preload, without adverse effects on coagulation and neonatal outcomes in healthy parturients undergoing caesarean delivery under spinal anaesthesia.