Maternal haemodynamics in pre-eclampsia compared with normal pregnancy during caesarean delivery

Comparing elective and emergency caesarean section by using bioimpedance method

BACKGROUND

There are limited studies focusing on hemodynamic changes between elective and emergent C/S cases. We considered that a better understanding of the alterations and physiological reactions in both situations with non-invasive novel technologies might be useful in managing maternal and fetal sides.

METHODS

In this prospective observational study, non-invasive hemodynamic changes were observed by using the whole-body impedance method using the NICaS™ device. CO, cardiac index (CI), stroke volume (SV), stroke index (SI), total peripheric resistance (TPR), and cardiac reserve (GGI) parameters were evaluated with a non-invasive method. Measurements were done initiating before surgery, 9 times of 5 min intervals.

RESULTS

All 95 patients finished the study. 47 cesarean sections were in the elective group, 48 were in the emergent group. SV in 4.5.6. time intervals were statistically increased in the elective group (p values: SvMl4: 0.025, SvMl5: 0.049, SvMl6: 0.044) (p < 0.05). SI in the second-time interval was statistically increased in the emergent group (p-value SI2: 0.047) (p < 0.05). SI in the 4th time interval was statistically increased in the elective group (p-value SI4: 0.047) (p < 0.05). CO measurements were not statistically different between groups in all time intervals for all comparisons. CI in the second time interval was statistically decreased in the elective group (p-value CI2: 0.012) (p < 0.05). GGI in the 4th time interval was statistically increased in the elective group (p-value GGI4: 0.035) (p < 0.05). TPRI in the second time interval was statistically increased in the elective group (p-value TPRI 2: 0.014) (p < 0.05).

CONCLUSIONS

Understanding normal hemodynamic values before, during, and after C/S is feasible and might help the clinician assess patients' cardiac performance with a reliable noninvasive technique. NICaS might be a reliable tool to evaluate patients' baseline values and diagnose complications earlier during the surgery.

Randomized Double-Blinded Comparison of Intermittent Boluses Phenylephrine and Norepinephrine for the Treatment of Postspinal Hypotension in Patients with Severe Pre-Eclampsia During Cesarean Section

Background

Norepinephrine has fewer negative effects on heart rate (HR) and cardiac output (CO) for treating postspinal hypotension (PSH) compared with phenylephrine during cesarean section. However, it remains unclear whether fetuses from patients with severe pre-eclampsia could benefit from the superiority of CO. The objective of this study was to compare the safety and efficacy of intermittent intravenous boluses of phenylephrine and norepinephrine used in equipotent doses for treating postspinal hypotension in patients with severe pre-eclampsia during cesarean section.

Methods

A total of 80 patients with severe pre-eclampsia who developed PSH predelivery during cesarean section were included. Eligible patients were randomized at a 1:1 ratio to receive either phenylephrine or norepinephrine for treating PSH. The primary outcome was umbilical arterial pH. Secondary outcomes included other umbilical cord blood gas values, Apgar scores at 1 and 5 min, changes in hemodynamic parameters including CO, mean arterial pressure (MAP), HR, stroke volume (SV), and systemic vascular resistance (SVR), the number of vasopressor boluses required, and the incidence of bradycardia, hypertension, nausea, vomiting, and dizziness.

Results

No significant difference was observed in umbilical arterial pH between the phenylephrine and norepinephrine groups (7.303±0.38 vs 7.303±0.44, respectively; P=0.978). Compared with the phenylephrine group, the overall CO (P=0.009) and HR (P=0.015) were greater in the norepinephrine group. The median [IQR] total number of vasopressor boluses required was comparable between the two groups (2 [1 to 3] and 2 [1 to 3], respectively; P=0.942). No significant difference was found in Apgar scores or the incidence of maternal complications between groups.

Conclusion

A 60 µg bolus of phenylephrine and a 4.5 µg bolus of norepinephrine showed similar neonatal outcomes assessed by umbilical arterial pH and were equally effective when treating PSH during cesarean section in patients with severe pre-eclampsia. Norepinephrine provided a higher maternal CO and a lower incidence of bradycardia.

Maternal Cardiac Function after Normal Delivery, Preeclampsia, and Eclampsia: A Prospective Study

Introduction

The aim of this study is to assess maternal cardiac function in the postpartum period, after 2 and 6 months in the parturient with preeclampsia and eclampsia.

Materials and Methods

Prospective study: 90 postpartum women after preeclampsia and eclampsia and 55 patients after an uncomplicated pregnancy. The parameters of maternal hemodynamics were recorded on days 1, 3, 5, 9, and 14 of postpartum period, after 2 and 6 months. The cardiac parameters were assessed.

Results

PE is accompanied by increased peripheral vascular resistance. The indicator of vascular resistance, SVR, is elevated for both mild and severe PE. With mild PE, a significant increase in SVR is observed up to 5 days of postpartum period, with severe PE/E up to 9 days. We found that in case of severe PE, SVR remains elevated to 6 months after delivery. The parameters of the contractile function of the heart (ESV, EDV, SV, SI, CO, СI, MVCF) were significantly decreased: with mild PE up to 5-9 days, with severe up to 9-14 days of puerperia. ESV, SV, SI, CO, and CI remain low with severe PE up to 6 months. The revealed decreasing of contractile function of the heart is a sign of asymptomatic heart failure.

Conclusions

The hemodynamics of the puerperas after PE and E is characterized by impaired contractility of the myocardium and an increase in the indices of peripheral resistance. The degree of deviation in the parameters of cardiac hemodynamics and vascular resistance depended on the severity of hypertensive complications of pregnancy.

A Comparative Study of Bolus Norepinephrine, Phenylephrine, and Ephedrine for the Treatment of Maternal Hypotension in Parturients with Preeclampsia During Cesarean Delivery Under Spinal Anesthesia

Background

This study aimed to compare the efficacy and safety of bolus norepinephrine, phenylephrine, and ephedrine in parturient with preeclampsia who had hypotension during cesarean delivery under spinal anesthesia.

Material/Methods

One hundred and sixty-six parturient women with preeclampsia who had a baseline systolic blood pressure (SBP) <80% during spinal anesthesia for cesarean section were divided into three treatment groups; bolus norepinephrine 4 μg (group N) (n=56), phenylephrine 50 μg (group P) (n=55), and ephedrine 4 mg (group E) (n=55). Primary outcomes included overall SBP and heart rate (HR) until delivery. Secondary outcomes included the incidence of tachycardia (HR >120 bpm), bradycardia (HR <60 bpm), hypertension (SBP >120% baseline), number of boluses of vasopressor required and episodes of hypotension, maternal side effects, and neonatal outcome.

Results

Overall HR in group N was significantly increased compared with group P (80.5±12 vs. 76.6±6.9 bpm; P=0.04), and significantly lower compared with group E (80.5±12 vs. 84.9±7.1 bpm; P=0.02). Parturients in group N had fewer episodes of bradycardia compared with group P (3.6% vs. 21.8%; RR=0.26l; 95% CI, 0.07–0.73; P=0.004) and fewer episodes of tachycardia compared with group E (16.1% vs. 36.4%; RR 0.54; 95% CI, 0.29–0.90; P=0.02).

Conclusions

A bolus dose of norepinephrine showed similar efficacy to phenylephrine but improved maternal and neonatal safety in parturients with preeclampsia with hypotension during cesarean section under spinal anesthesia.

Maternal cardiovascular hemodynamics in normotensive versus preeclamptic pregnancies: a prospective longitudinal study using a noninvasive cardiac system (NICaS™)

BACKGROUND

Preeclampsia is among the most common medical complications of pregnancy. The clinical utility of invasive hemodynamic monitoring in preeclampsia (e.g., Swan-Ganz catheter) is controversial. Thoracic impedance cardiography (TIC) and Doppler echocardiography are noninvasive techniques but they both have important limitations. NICaS™ (NI Medical, PetachTikva, Israel) is a noninvasive cardiac system for determining cardiac output (CO) that utilizes regional impedance cardiography (RIC) by noninvasively measuring the impedance signal in the periphery. It outperformed any other impedance cardiographic technology and was twice as accurate as TIC.

METHODS

We used the NICaS™ system to compare the hemodynamic parameters of women with severe preeclampsia (PET group, n = 17) to a cohort of healthy normotensive pregnant women with a singleton pregnancy at term (control group, n = 62) (1/2015-6/2015). Heart rate (HR), stroke volume (SV), CO, total peripheral resistance (TPR) and mean arterial pressure (MAP) were measured 15-30 min before CS initiation, immediately after administering spinal anesthesia, immediately after delivery of the fetus and placenta, at the abdominal fascia closure and within 24-36 and 48-72 h postpartum.

RESULTS

The COs before and during the CS were significantly higher in the control group compared to the PET group (P < .05), but reached equivalent values within 24-36 h postpartum. CO peaked at delivery of the newborn and the placenta and started to decline afterwards in both groups. The MAP and TPR values were significantly higher in the PET group at all points of assessment except at 48-72 h postpartum when it was still significantly higher for MAP while the TPR only exhibited a higher trend but not statistically significant. The NICaS™ device noninvasively demonstrated low CO and high TPR profiles in the PET group compared to controls.

CONCLUSIONS

The immediate postpartum period is accompanied by the most dramatic hemodynamic changes and fluid shifts, during which the parturient should be closely monitored. The NICaS™ device may help the clinician to customize the most optimal management for individual parturients. Our findings require validation by further studies on larger samples.

Cardiac hemodynamics before, during and after elective cesarean section under spinal anesthesia in low-risk women

OBJECTIVE

The aim of this study was to describe maternal central hemodynamic parameters before and during delivery as well at the early puerperium in healthy women undergoing elective cesarean section (CS) at term.

STUDY DESIGN

The noninvasive Cardiac System (NICaS, NI Medical, Petah-Tikva, Israel) is a regional impedance device that measures cardiac output (CO) and its derivatives with a good correlation with the gold standard Swan-Ganz catheter. We performed a prospective longitudinal study of healthy women with a singleton pregnancy at term. Maternal hemodynamic parameters were assessed by the NICaS at six time points: a few minutes before undergoing an elective CS, immediately after receiving spinal anesthesia, immediately after delivery of the fetus and placenta, after abdominal fascia closure, and within 24 to 36 and 48 to 72 h postpartum.

RESULT

Sixty-one consenting women were recruited during the study period (January 2015 to June 2015). Baseline (pre-CS) mean arterial pressure (MAP) was 87.7±7.9 mm Hg, baseline CO was 7.5±1.7 l per min and baseline total peripheral resistance (TPR) was 994±301 dyne × s per cm⁵. After spinal anesthesia CO significantly increased by 13%, no significant changes were observed in MAP or TPR. Immediately after delivery, a nadir for all parameters was reached: MAP and TPR were significantly reduced by 8% and 26%, respectively (comparing to pre-CS), and CO further increased by 9% (24% comparing to pre-CS). After fascia closure, partial recoveries of all parameters were observed. Twenty-four to thirty-six hours postpartum MAP returned to pre-CS values, while CO and TPR reached -9% and +11% comparing to baseline, respectively. None of the parameters differed significantly between 24 to 36 and 48 to 72 h postpartum.

CONCLUSION

Significant hemodynamic changes (reduction of TPR and increase of CO) take place at the time of delivery of fetus and placenta. Knowledge of normal hemodynamic values using a reliable noninvasive technique during various stages of pregnancy and the postpartum period is feasible, and might assist clinicians in assessing the level of patient deviation from expected cardiac performance, especially in high-risk women.

SOMANZ guidelines for the management of hypertensive disorders of pregnancy 2014

This guideline is an evidence based, practical clinical approach to the management of Hypertensive Disorders of Pregnancy. Since the previous SOMANZ guideline published in 2008, there has been significant international progress towards harmonisation of definitions in relation to both the diagnosis and management of preeclampsia and gestational hypertension. This reflects increasing knowledge of the pathophysiology of these conditions, as well as their clinical manifestations. In addition, the guideline includes the management of chronic hypertension in pregnancy, an approach to screening, advice regarding prevention of hypertensive disorders of pregnancy, and discussion of recurrence risks and long term risk to maternal health. The literature reviewed included the previous SOMANZ Hypertensive Disorders of Pregnancy guideline from 2008 and its reference list, plus all other published National and International Guidelines on this subject. Medline, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Registry of Controlled Trials (CCRCT), National Institute for Health and Care Excellence (NICE) Evidence Search, and Database of Abstracts and Reviews of Effects (DARE) were searched for literature published between January 2007 and March, 2014.

Fluid management in pre-eclampsia

Intravenous fluid given to women with pre-eclampsia may be a necessary form of treatment; however, intravenous fluid therapy can also cause iatrogenic pulmonary oedema. The indications for the use of intravenous fluids, the titration of the amount of fluid given and the use of invasive monitoring have not been subject to adequate examination in randomised studies. Clinical experience, combined with available evidence and a reasoned approach are the basis for a suggested management algorithm.

Noninvasive cardiac monitoring in pregnancy: impedance cardiography versus echocardiography

OBJECTIVE

The objective of this study was to report thoracic impedance cardiography (ICG) measurements and compare them with echocardiography (echo) measurements throughout pregnancy and in varied maternal positions.

METHOD

A prospective cohort study involving 28 healthy parturients was performed using ICG and echo at three time points and in two maternal positions. Pearson's correlations, Bland-Altman plots and paired t-tests were used for statistical analysis.

RESULT

Significant agreements between many but not all ICG and echo contractility, flow and resistance measurements were demonstrated. Differences in stroke volume (SV) due to maternal position were also detected by ICG in the antepartum (AP) period. Significant trends were observed by ICG for cardiac output and thoracic fluid content (TFC; P<0.025) with advancing pregnancy stages.

CONCLUSION

ICG and echo demonstrate significant correlations in some but not all measurements of cardiac function. ICG has the ability to detect small changes in SV associated with maternal position change. ICG measurements reflected maximal cardiac contractility in the a AP period yet reflected a decrease in contractility and an increase in TFC in the postpartum period.

A review of the impact of phenylephrine administration on maternal hemodynamics and maternal and neonatal outcomes in women undergoing cesarean delivery under spinal anesthesia

Phenylephrine is effective for the management of spinal anesthesia-induced hypotension in parturients undergoing cesarean delivery under spinal anesthesia. While ephedrine was previously considered the vasopressor of choice in obstetric patients, phenylephrine is increasingly being used. This is largely due to studies suggesting improved fetal acid-base status with the use of phenylephrine as well as the low incidence of hypotension and its related side effects with prophylactic phenylephrine regimens. This review highlights the effects of phenylephrine compared with ephedrine on maternal hemodynamics (arterial blood pressure, heart rate, and cardiac output), and occurrence of intraoperative nausea and vomiting. The impact of the administration of phenylephrine as a bolus for the treatment of established hypotension compared with its administration as a prophylactic infusion is discussed. This article also reviews the impact of phenylephrine compared with ephedrine on uteroplacental perfusion, and fetal outcomes such as neonatal acid-base status and Apgar scores. The optimum dosing regimen for phenylephrine administration is also discussed.

A retrospective study of the outcome of cesarean section for women with severe pre-eclampsia in a third world setting

Objective:

To compare the outcome of subarachnoid block (spinal anesthesia) and general anesthesia in Cesarean delivery for women with severe pre-eclampsia.

Methods:

A retrospective study of women with severe pre-eclampsia requiring Cesarean section from January 2005 to June 2009 was carried out. Maternal age, parity, gestational age at delivery, booking status, Apgar scores, maternal and perinatal mortality of the sub-arachnoid block group were compared with those of general anesthesia group using χ², Student t-test and Fischer exact test.

Results:

There were no significant difference between the two groups in overall maternal mortality (5.4% vs. 11.9%, P=0.5) and perinatal mortality (2.7% vs. 11.9%, P=0.15). The general anesthesia group had significantly more birth asphyxia than the spinal group (55.9% vs. 27.0%, P=0.0006).

Conclusion:

There was no significant difference in the maternal and perinatal mortality outcome of cesarean delivery between women with severe pre-eclampsia who had regional anesthesia and those that had general anesthesia. There was significantly higher proportion of birth asphyxia in babies of women who received general anesthesia.

Diagnosis and management of pre-eclampsia: an update

Pre-eclampsia is a significant, multifactorial, multiorgan disease affecting 5%-8% of all pregnancies in the US where it is the third leading cause of maternal mortality. Despite improvements in the diagnosis and management of pre-eclampsia, severe complications can occur in both the mother and the fetus, and there is no effective method of prevention. Early detection and identification of pregnant women most at risk of developing the disease have proven challenging, but recent efforts combining biochemical and biophysical markers are promising. Efforts at prevention of pre-eclampsia with aspirin and calcium have had limited success, but research on modifiable risk factors, such as obesity surgery, are encouraging. Obstetric management of severe pre-eclampsia focuses on medical management of blood pressure and prevention of seizures using magnesium sulfate, but the ultimate cure remains delivery of the fetus and placenta. Timing of delivery depends on several factors, including gestational age, fetal lung maturity, and most importantly, disease severity. Anesthetic management includes regional anesthesia with careful evaluation of the patient's airway, volume status, and coagulation status to reduce morbidity and mortality. The potential complications of general anesthesia, including intracranial hemorrhage, in these patients make regional anesthesia the preferred choice in many cases. Nevertheless, it is important to be aware of the contraindications to neuraxial anesthesia and to prepare always for the possibility of encountering a difficult airway.

The effect of Helicobacter pylori eradication on macrophage migration inhibitory factor, C-reactive protein and fetuin-a levels

OBJECTIVES

To determine the effect of Helicobacter pylori (H. pylori) eradication on blood levels of high-sensitivity C-reactive protein (hs-CRP), macrophage migration inhibitory factor and fetuin-A in patients with dyspepsia who are concurrently infected with H. pylori.

METHODS

H.pylori infection was diagnosed based on the 14C urea breath test (UBT) and histology. Lansoprazole 30 mg twice daily, amoxicillin 1 g twice daily, and clarithromycin 500 mg twice daily were given to all infected patients for 14 days; 14C UBT was then re-measured. In 30 subjects, migration inhibitory factor, fetuin-A and hs-CRP levels were examined before and after the eradication of H. pylori infection and compared to levels in 30 healthy subjects who tested negative for H. pylori infection.

RESULTS

Age and sex distribution were comparable between patients and controls. Migration inhibitory factor and hs-CRP levels were higher, and fetuin-A levels were lower, in H. pylori-infected patients (p<0.05). Following eradication of H. pylori, migration inhibitory factor and hs-CRP levels were significantly decreased, whereas fetuin-A levels were increased. However, eradication of the organism did not change lipid levels (p>0.05).

CONCLUSION

These findings suggest that H. pylori eradication reduces the levels of pro-inflammatory cytokines such as migration inhibitory factor and hs-CRP and also results in a significant increase in anti-inflammatory markers such as fetuin-A.

Clinical evaluation of the flotrac/Vigileo system for continuous cardiac output monitoring in patients undergoing regional anesthesia for elective cesarean section: a pilot study

BACKGROUND

Spinal anesthesia for cesarean delivery may cause severe maternal hypotension and a decrease in cardiac output. Compared to assessment of cardiac output via a pulmonary artery catheter, the FloTrac/Vigileo system may offer a less invasive technique. The aim of this study was to evaluate cardiac output and other hemodynamic measurements made using the FloTrac/Vigileo system in patients undergoing spinal anesthesia for elective cesarean section.

METHODS

A prospective study enrolling 10 healthy pregnant women was performed. Hemodynamic parameters were continuously obtained at 15 main points: admission to surgery (two baseline measurements), after preload, after spinal anesthesia administration and 4 time points thereafter (4, 6, 8 and 10 min after anesthesia), at skin and uterine incision, newborn and placental delivery, oxytocin administration, end of surgery, and recovery from anesthesia. Hemodynamic therapy was guided by mean arterial pressure, and vasopressors were used as appropriate to maintain baseline values. A repeated measures ANOVA was used for data analysis.

RESULTS

There was a significant increase in heart rate and a decrease of stroke volume and stroke volume index up to 10 min after spinal anesthesia (P < 0.01). Importantly, stroke volume variation increased immediately after newborn delivery (P < 0.001) and returned to basal values at the end of surgery. Further hemodynamic parameters showed no significant changes over time.

DISCUSSION AND CONCLUSIONS

No significant hemodynamic effects, except for heart rate and stroke volume changes, were observed in pregnant women managed with preload and vasopressors when undergoing elective cesarean section and spinal anesthesia.

Severe preeclampsia: anesthetic implications of the disease and its management

Preeclampsia is a significant, multifactorial, multiorgan disease affecting 6%-8% of all pregnancies in the United States and is the third leading cause of maternal mortality. As such, it is incumbent upon any anesthesia provider involved in obstetric cases to be familiar with the varied manifestations of the disease, management goals from an obstetric standpoint, and the implications for provision of anesthesia in this patient group. Despite improvements in the diagnosis and management of preeclampsia, severe complications can occur in both the mother and the fetus. A systematic approach to the anesthetic evaluation is therefore necessary to reduce morbidity and mortality and to improve outcomes. The potential pitfalls of general anesthesia, including failed intubation, in these complicated patients make regional anesthesia the preferred choice in many cases. Recent studies have shown that spinal anesthesia is often appropriate for preeclamptic patients, even in severe cases. Nevertheless, it is important to be aware of the potential contraindications to neuraxial anesthesia and to prepare for the possibility of encountering a difficult airway.

The role of the anaesthetist in the management of the pre-eclamptic patient

PURPOSE OF REVIEW

Recent literature on the anaesthetist's role in the management of the patient with severe pre-eclampsia is reviewed, with particular emphasis on the role of regional anaesthesia.

RECENT FINDINGS

Laboratory findings in pre-eclamptic women include increased levels of markers of oxidative stress and circulating tyrosine kinase 1, and inflammatory activation of leucocytes. Magnesium sulphate is the most effective agent for seizure prophylaxis. The optimal pharmacological agents for acute control of blood pressure remain controversial. The benefits of epidural analgesia in labour are well established. Single-shot spinal anaesthesia for caesarean section is safe in the absence of contraindications. Successful use of combined spinal-epidural anaesthesia has been described. Most studies on maternal haemodynamics have employed heart rate and blood pressure data as surrogate measures of cardiac output. Noninvasive cardiac output studies provide further insight into the haemodynamic response during neuraxial techniques for caesarean section.

SUMMARY

The value of regional anaesthesia cannot be over-emphasized. Recent research into spinal anaesthesia for caesarean section suggests a lower susceptibility to hypotension and probably less impairment of cardiac output than in healthy parturients. Noninvasive cardiac output measurement may also have advantages in critical care management.