Maternal hemodynamics during cesarean delivery assessed by whole-body impedance cardiography.
ABSTRACT This descriptive study was designed to evaluate maternal hemodynamics and cardiovascular responses to delivery during cesarean section (CS) under spinal anesthesia. We also assessed the feasibility of a noninvasive and continuous method of measuring cardiac output, namely whole-body impedance cardiography (ICG(WB)), during elective CS. Because of the techniques used in previous studies, only fractionated data on maternal hemodynamics during CS are available to date.
We studied 10 healthy women with normal pregnancies and two pregnant women with heart disease undergoing elective CS. Mean arterial pressure (MAP), heart rate (HR), stroke index (SI), cardiac index (CI) and systemic vascular resistance index (SVRI) were recorded continuously during CS, during the period of dissipation of anesthesia and on the second to fifth postpartum day. Analysis of variance for repeated measurements (anova) and the paired sample t-test were used in statistical analysis.
The hemodynamic parameters could be registered continuously during the whole procedure. At the point of delivery, a 47% increase in CI and a 39% decrease in SVRI were recorded, while MAP remained stable. These changes occurred within 2 min of delivery of the newborn and persisted on average for 10 min.
Sudden and significant hemodynamic changes take place at the moment of delivery. Intact physiological cardiovascular compensation mechanisms are needed to adapt to these challenges. Whole-body impedance cardiography may offer a useful noninvasive tool to monitor hemodynamics during cesarean section.
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ABSTRACT: Little is known about maternal hemodynamics after Cesarean delivery. Uterine contractions may increase cardiac output. Oxytocin is the first-line treatment for uterine atony, although the effects of the long-acting oxytocin analogue carbetocin are comparable with that of oxytocin. The authors analyzed the effects of i.v. oxytocin 5 U, carbetocin 100 μg, and placebo on hemodynamics, uterine tone, adverse events, and blood loss after Cesarean delivery. This was a randomized, double-blinded, placebocontrolled, parallel-group comparison of carbetocin and oxytocin after elective Cesarean delivery of singletons under spinal anesthesia (n = 76). Continuously measured invasive systolic arterial pressure was the primary outcome measure. The mean systolic arterial pressure decrease was 28 mmHg (95% CI, 22-34) after oxytocin and 26 mmHg (95% CI, 20-31) after carbetocin. The decrease was greatest after 80 (95% CI, 71-89) and 63 s (95% CI, 55-72), respectively (P = 0.006). The differences were nearly undetectable after 2.5 min, although the effect of carbetocin was slightly greater than placebo (P < 0.001). The group differences in systolic arterial pressure decreased over 5 min and were gone at 1 h. Heart rate and cardiac output increased in all three groups. Stroke volume increased after oxytocin and carbetocin but was unchanged after placebo. The hemodynamic side effects of oxytocin 5 U and carbetocin 100 μg were comparable. The lack of an increase in stroke volume in the placebo group challenges the theory that uterine contraction causes autotransfusion of uterine blood, leading to an increase in preload.Anesthesiology 09/2013; 119(3):541-51. · 6.17 Impact Factor
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ABSTRACT: During cesarean delivery with neuraxial anesthesia, maternal hemodynamic changes occur with prehydration of intravenous fluid, block onset and delivery of the fetus. The direction and degree of these hemodynamic changes is influenced by multiple interacting variables including the physiologic and anatomic alterations of pregnancy, maternal and fetal characteristics, comorbid conditions, the neuraxial technique, the amount of blood loss and fluid and drug administration. In this review, the influences of each of these variables, as well as the techniques used to evaluate, prevent and treat hypotension, are discussed to provide a comprehensive overview of the cardiovascular alterations in the parturient undergoing cesarean delivery with neuraxial anesthesia.Expert Review of Obstetrics & Gynecology 01/2014; 7(1).
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ABSTRACT: Abstract Objectives: To investigate the effect of spinal anesthesia on cerebral rSO2 during elective cesarean delivery (CD). Methods: Thirty-four women scheduled for elective CD under spinal anesthesia were recruited. In the operating room rSO2 of the left and right forehead and right thigh was recorded using three disposable sensors. 1.8-2.0 mL of 0.75% ropivacaine plus 10 μg of fentanyl were injected intrathecally. Systolic and diastolic blood pressure, heart rate, SpO2 as well as rSO2 of the left and right forehead areas and right thigh were recorded before, 5, 10, and 25 to 50 minutes after spinal injection, after uterine incision and placenta delivery, and analyzed with ANOVA repeated measures. The study was approved by the Aretaieio Hospital Institutional Review Board and registered with ClinicalTrials.gov (ID: NCT01669135). Results: The rSO2 left and right frontal area values decreased significantly from baseline (p=0.0001 and p=0.0001 respectively), with most remarkable decreases 5 and 10 minutes after spinal injection, from 64.7 (SD 8.7)% to 55.6 (SD 9.3)% and 56.5 (SD 9.5)%, (p=0.0001 and p=0.0001) for the left and from 63.1 (SD 7.7)% to 54.6 (SD 9.3)% and 55.8 (SD 8.9)%, (p= 0.016 and p=0.007), for the right forehead respectively. The rSO2 right thigh values increased significantly during the study period (p=0.0001). Key limitations: Contribution of extracranial circulation to the rSO2, lack of PaCO2 and cardiac output measurements. Conclusions: Women undergoing CD under spinal anesthesia may present decreases in cerebral rSO2. The clinical impact of these results remains to be determined.Current Medical Research and Opinion 10/2013; · 2.37 Impact Factor