Comparison of intravenous bolus doses of phenylephrine vs ephedrine along with crystalloid co-loading in the prevention of hypotension during spinal anesthesia for caesarean section

Caesarean section was the first obstetrical operation that saves the life of the baby when normal delivery fails. Spinal anaesthesia is the most appropriate method for caesarean section. But hypotension is the most common side effect of it in patient with pregnant uterus. To compare the vasopressor effects of ephedrine and phenylephrine in ameliorating hypotension in elective caesarean delivery receiving crystalloid coloading, during intrathecal bupivacaine injection.: Study participants were randomly divided into two groups of 50 patients each. After subarachnoid block, all the parturients were given rapid administration of ringer lactate solution 20ml/kg, during the initial 5 minutes of surgery the parameters such as oxygen saturation, blood pressure and pulse rate recorded for every one minute followed by every five minutes until the completion of the surgery. The incidence of hypotension, bradycardia, nausea/vomiting, block height and requirements of vasopressor (ephedrine and phenylephrine) were recorded. Apgar score, and blood sample from umbilical cord was taken and sent for blood gas analyses to determine the neonatal outcome.: Vasopressor consumption was more in phenylephrine group (92±112 µg) compared to ephedrine group (4.8±5.5 mg) which was statistically significant p=0.0001. The neonatal outcome was statistically significant regarding umbilical cord pH (Group E-7.2±0.06 and Group P-7.37±0.04 with p=0.002) but clinically no true fetal acidosis in either groups and no significant changes regarding Apgar score in the two groups.: Thus we conclude that that ephedrine 6 mg and phenylephrine 100 µg does not differ in their efficacy to manage hypotension during spinal anaesthesia for caesarean delivery. However, maternal bradycardia was more in the phenylephrine group with equal incidence of fetal acidosis in the study groups.

Initial Results on Primary Field Cancellation of Magnetic Induction Spectroscopy Technique for Fetal Acidosis Detection using COMSOL Multiphysics

Monitoring of fetal condition during labor could save hundred lives in a single year. During labor, fetus is at critical condition as acidosis may occur suddenly without any early symptoms. Invasive method such as Fetal Blood Sampling (FBS) has been used to detect the decline in pH level of fetus. However, fetal loss rate after FBS may range from 1.4% up to 25%. In this paper, magnetic field induction spectroscopy was implemented to determine fetal acidosis by using primary magnetic field cancellation technique. Magnetic Induction Spectroscopy (MIS) probe was design where transmitter coil (TX) is perpendicular to receiver coil (RX). The result shows that the secondary magnetic field produced have been successfully measured without any interruption from primary magnetic field. By using transmitter input 1A, it shows that voltage is inversely proportional to the blood pH due to the conductivity properties of blood.

Correlation between Intrapartum Cardiotocogram findings and cord blood pH in term and preterm labors

Background: The purpose of intrapartum fetal monitoring by cardiotocograph (CTG) is to identify early signs of developing hypoxia so that appropriate action can be taken to improve the perinatal outcome. Although CTG findings are well known to monitor the progress of the labor due to the paucity of recommendations, there has always been a clinical dilemma as the term fetuses respond differently than a preterm fetus. However, umbilical cord blood pH can distinguish the infant at high risk for asphyxia and related sequel. Therefore, because of differences in fetal physiology in term and preterm fetuses, CTG findings vary, and hence the validity of CTG to determine fetal acidosis should be different. Aims and Objectives: This study aimed to correlate abnormal intrapartum CTG findings with umbilical cord blood pH in term and preterm labor and thus evaluate the success of CTG in predicting fetal acidosis during labor. Methods: The present study included 210 women in labor (70 preterm and 140 term) with abnormal intrapartum CTG that was classified as per 2015 revised International Federation of Gynecologists and Obstetrician (FIGO) guidelines. Immediately after delivery 2 ml Umbilical artery cord blood sample was taken in a pre-heparinized syringe for analysis, pH <=7.2 was taken as acidosis and pH >7.2 was taken as normal. The measured data were maternal general characteristics which included gravida status, associated comorbidities, method of induction and character of liquor, the intrapartum CTG tracings recorded the cord arterial blood pH and the neonatal characteristics such as APGAR score and neonatal outcome. Results: Data from 70 preterm labor was compared with 140 term labor. In this study, 20.9 % of the babies had acidosis. Suspicious CTG due to decreased variability were more common in the preterm group than in the term group (21.4% vs. 8.6% p<0.05). Positive predictive value (PPV) of abnormal CTG for fetal acidosis in the preterm group was found to be higher than that in term group, PPV of pathological CTG being even higher than suspicious CTG. Women with suspicious CTG had 82 % less risk of fetal acidosis as compared to pathological CTG. Women with Bradycardia had 5.9 times the risk of fetal acidosis as compared with normal and tachycardia. Conclusion: Abnormal CTG should be managed appropriately without any delay to prevent acidosis and cord blood pH should be done in all labors with abnormal CTG. However, our findings of a higher incidence of lower cord blood pH and suspicious CTG due to decreased variability alone, highlight the limitation of criteria currently used for interpretation of CTG in preterm labors.

COMPARISON OF THE EFFECT OF PHENYLEPHRINE AND EPHEDRINE ON UMBILICALARTERIAL BLOOD GAS PARAMETERS IN ELECTIVE CAESAREAN SECTION UNDER LUMBAR SUBARACHNOID BLOCK

Introduction: Potential side effects such as supraventricular tachycardia, tachyphylaxis, and most importantly, fetal acidosis render the use of ephedrine as a rst line agent to treat hypotension in obstetric patient debatable. Phenylephrine, an alternative drug, has a reduced incidence of nausea and vomiting as well as decreased fetal acidosis, which gives it an advantage over the use of ephedrine. Materials and methods: We conducted an observational study in 68 ASA II patients scheduled for lower segment caesarean section. Parturients who satised the inclusion criteria were randomly assigned into one of the two groups of 34 each- group P with parturients who were to receive phenylephrine boluses in 100 mcg increments and group E with parturients who were to receive ephedrine boluses in 6mg increments when they developed hypotension. Fetal umbilical arterial blood gas was analyzed and parameters were compared. Results: On analyzing umbilical arterial blood values, a lower mean pH was found in group E (7.27± 0.09) when compared to group P (7.3± 0.04). Also a higher PCO value (49± 7.4) was found in group E when compared to group P (43.9 ± 6.4). Other umbilical arterial blood gas values were 2 comparable between both groups

Prediction of non-reassuring fetal status and umbilical artery acidosis by the maternal characteristic and ultrasound prior to induction of labor

Objective To investigate the predictive value of pre-induction digital examination, sonographic measurements and parity for the prediction of non-reassuring fetal status and cord arterial pH < 7.2 prior to the induction of labor (IOL). Method This was a prospective observational study, including 384 term pregnancies undergoing IOL. Before the IOL, the Bishop score (BS) by digital examination, sonographic Doppler parameters and the estimated fetal weight (EFW) was assessed. The fetal cord arterial was sampled to measure the pH at delivery. Multivariate logistic regression analysis was performed to identify independent predictors of non-reassuring fetal status and low cord arterial pH. Results Forty four cases (11.5%) had non-reassuring fetal status, and 76 cases (19.8%) had fetal cord arterial pH < 7.2. In the non-reassuring fetal status group, the incidence of cord arterial pH < 7.2 was significantly higher than that in the normal fetal heart rate group (χ2 = 6.401, p = 0.011). Multivariate analysis indicated that significant independent predictors of non-reassuring fetal status were nulliparity (adjusted odds ratio [AOR]: 3.746, p = 0.003), EFW < 10th percentile (AOR: 3.764, p = 0.003) and cerebroplacental ratio (CPR) < 10th centile (AOR:4.755, p < 0.001). In the prediction of non-reassuring fetal status, the performance of the combination of nulliparity and EFW < 10th percentile was improved by the addition of CPR < 10th percentile (AUC: 0.681, (95%CI: 0.636 to 0.742) vs 0.756, (95%CI:0.713 to 0.795)), but the difference was not significant (DeLong test: z = 1.039, p = 0.053).. None of the above variables were predictors of cord arterial pH < 7.2. Conclusion The risk of fetal acidosis has increased in cases of non-reassuring fetal status. Nulliparity, small for gestational age and CPR < 10th centile are independent predictors for non-reassuring fetal status in term fetuses, though the addition of CPR < 10th centile could not significantly improve the screening accuracy.