Umbilical Cord Blood Gas Values Research Articles

Early or delayed cord clamping during transition of term newborns: does it make any difference in cerebral tissue oxygenation?

BackgroundAccording to the World Health Organization’s recommendation, delayed cord clamping in term newborns can have various benefits. Cochrane metaanalyses reported no differences for mortality and early neonatal morbidity although a limited number of studies investigated long-term neurodevelopmental outcomes. The aim of our study is to compare the postnatal cerebral tissue oxygenation values in babies with early versus delayed cord clamping born after elective cesarean section.MethodsIn this study, a total of 80 term newborns delivered by elective cesarean section were included. Infants were randomly grouped as early (clamped within 15 s, n:40) and delayed cord clamping (at the 60th second, n:40) groups. Peripheral arterial oxygen saturation (SpO2) and heart rate were measured by pulse oximetry while regional oxygen saturation of the brain (rSO2) was measured with near-infrared spectrometer. Fractional tissue oxygen extraction (FTOE) was calculated for every minute between the 3rd and 15th minute after birth. (FTOE = pulse oximetry value-rSO2/pulse oximetry value). The measurements were compared for both groups.ResultsThe demographical characteristics, SpO2 levels (except postnatal 6th, 8th, and 14th minutes favoring DCC p < 0.05), heart rates and umbilical cord blood gas values were not significantly different between the groups (p > 0.05). rSO2 values were significantly higher while FTOE values were significantly lower for every minute between the 3rd and 15th minutes after birth in the delayed cord clamping group (p < 0.05).ConclusionOur study revealed a significant increase in cerebral rsO2 values and a decrease in FTOE values in the delayed cord clamping (DCC) group, indicating a positive impact on cerebral oxygenation and hemodynamics. Furthermore, the DCC group exhibited a higher proportion of infants with cerebral rSO2 levels above the 90th percentile. This higher proportion, along with a lower of those with such parameter below the 10th percentile, suggest that DCC may lead to the targeted/optimal cerebral oxygenetaion of these babies. As a result, we recommend measuring cerebral oxygenation, in addition to peripheral SpO2, for infants experiencing perinatal hypoxia and receiving supplemental oxygen.

Plasenta ve Umblikal Kord Özellikleri ile Fetal Distress Arasındaki İlişki

Aim: In our study, we investigated the relationship between placental thickness and weight, umbilical cord diameter and length, and placental cord insertion site with fetal distress, and its effects on the baby's APGAR score and cord blood gas.&#x0D; Materials and methods: In our study, the data of the patients who gave birth in our hospital, whose gestational patient was between 37+0- 41+6 weeks, and between the ages of 18-45 were recorded prospectively. 385 patients (196 patients fetal distress and 189 patients elective cesarean section) were included in the study. Demographic characteristics, placental thickness and weight, umbilical cord diameter and length, insertion site of the umbilical cord into the placenta, newborn gender, first- and fifth-minute. Apgar score, and umbilical cord blood gas values were recorded. All parameters were compared between both groups.&#x0D; Results: When both groups are compared, Maternal age (29.13 ± 5.20 vs. 25.67 ± 5.27, p

Association of Umbilical Cord Blood Gas Values With Mortality and Severe Neurologic Injury in Preterm Neonates &lt;29 Weeks’ Gestation: A National Cohort Study

(Am J Obstet Gynecol. 2022;227:85.e1–10) The acid-base status of a neonate at the time of birth is determined through analysis of umbilical cord blood gas values. Deranged umbilical cord arterial (UA) and umbilical cord venous (UV) blood gas values can be linked to poor neonatal outcomes. Previous studies have found an association between a UA or UV pH value of &lt;7.0 and neonatal mortality. However, the relationship between umbilical cord blood gas values and adverse outcomes, specifically in preterm neonates born before 29 weeks gestation, is not clear. This study aimed to explore the association between umbilical cord blood gas values with neonatal mortality and severe neurological injury (SNI) in infants born before 29 weeks gestation.

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

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. 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. 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. 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.

Association of umbilical cord blood gas values with mortality and severe neurologic injury in preterm neonates

Umbilical cord arterial and venous blood gas values reflect the acid-base balance status of a newborn at birth. Derangement in these values has been linked to poor neonatal outcomes in term and late preterm neonates; however, the utility of these values in preterm neonates of <29 weeks' gestation is unclear. This study aimed to determine the associations of umbilical cord arterial and venous blood gas values with neonatal mortality and severe neurologic injury in extremely preterm neonates and to identify the cutoff values associated with 2.5-fold increases or decreases in the posttest probabilities of outcomes. This was a retrospective cohort study of neonates who were born at 23+0 to 28+6 weeks' gestation between January 1, 2018 and December 31, 2019, and who were admitted to neonatal units in Canada. Various cut-offs of umbilical cord blood gas values and lactate values were studied. The main outcomes were mortality before discharge from the neonatal unit and severe neurologic injury defined as grade 3 or 4 periventricular or intraventricular hemorrhage or periventricular leukomalacia. The outcome rates were calculated for various cutoff values of umbilical cord blood gas parameters and were adjusted for birthweight, gestational age, sex, and multiple births. Likelihood ratios were calculated to derive posttest probabilities. A total of 1040 and 1217 neonates had analyzable umbilical cord arterial and venous blood gas values, respectively. In the cohort, the mean (standard deviation) gestational age was 26.5 (1.5) weeks, the mean birthweight was 936 (215) g, the prevalence of mortality was 10% (105/1040), and the prevalence of severe neurologic injury was 9% (92/1016). An umbilical cord arterial pH of ≤7.1 and base excess of ≤-12 mmol/L were associated with >2.5-fold higher posttest probability of mortality, and an umbilical cord arterial or venous lactate value of <3 was associated with a 2.5-fold lower posttest probability of mortality. An umbilical cord arterial lactate value of <3 was associated with a lower posttest probability of severe neurological injury. In preterm neonates of <29 weeks' gestation, low umbilical cord arterial pH and high umbilical cord arterial base excess values were associated with a clinically important increase in the posttest probability of mortality, whereas low umbilical cord arterial or venous lactate values were associated with a decrease in the posttest probability of mortality.

Randomized trial of bolus ephedrine or mephentermine for maintenance of arterial pressure and fetal outcome during spinal anesthesia for the cesarean section

Background and Aims: Spinal anesthesia remains the preferred choice for cesarean deliveries, but hypotension is one of the common complications which may have detrimental effects on both the mother and fetus. In this study, we compared the efficacy and adverse effects of bolus doses of ephedrine hydrochloride and mephentermine sulfate administered intravenously to treat spinal-induced hypotension and the fetal outcomes through Apgar scores and umbilical cord blood gas analysis in the lower segment cesarean section. Material and Methods: In this prospective, randomized, double-blind study, 60 patients undergoing the lower segment cesarean section (LSCS) under spinal anesthesia were randomized into two groups of 30 each using computer-generated random numbers which were kept in an opaque envelope. Patients were pre-loaded with Ringer's lactate solution 10 ml/kg before the spinal anesthesia. Hypotension was defined as the fall in systolic blood pressure of less than or equal to 20% of the baseline or systolic blood pressure of less than 90 mmHg. Whenever hypotension occurred, patients in group E (ephedrine) received a bolus dose of ephedrine 6 mg intravenous and patients in group M (mephentermine) received a bolus dose of mephentermine 6 mg intravenous. Intra-operative recording included maternal hemodynamic parameters and the number of bolus doses of study drugs required to treat maternal hypotension and the adverse effects of study drugs. The Apgar score and umbilical cord blood gas values were recorded. Data were analyzed by analysis of variance test, Student's t-test, and Chi-square test. A P value of < 0.05 was considered as significant. Results: There was a statistically significant (p < 0.05) increase in systolic and mean arterial blood pressure at the second min and fourth min after administration of ephedrine in group E compared to mephentermine in group M. The systolic blood pressure at the second min in the ephedrine group was 114.3 ± 12.06, whereas in the mephentermine group, it was 106.10 ± 8.41 and was statistically significant (p < 0.05). At the fourth min, the systolic blood pressure in the ephedrine group was 115.03 ± 8.87, whereas in the mephentermine group, it was 108.46 ± 8.10 and was statistically significant (p < 0.05). There was a transient increase in heart rate immediately after administration of spinal anesthesia. The mean number of bolus doses of vasopressor consumption was 2.4 (14.4 mg) in the ephedrine group and 2 (12 mg) in the mephentermine group. The umbilical cord blood gas analysis and Apgar scores were similar in both the groups. Three patients (10%) developed bradycardia in the mephentermine group compared to the ephedrine group (0%). The incidence of nausea (13.3% vs 3.3%) and vomiting (10% vs 1%) was higher in the ephedrine group compared to the mephentermne group, and it was not statistically significant (p > 0.05). No significant differences were observed in the umbilical arterial blood pH and Apgar scores. Conclusion: In conclusion, after hypotension, ephedrine and mephentermine administration as bolus doses are equally efficacious in preventing spinal-induced hypotension in patients undergoing the cesarean section and are associated with similar neonatal outcomes.

Different antecedents and neonatal condition in neonatal arterial ischemic stroke and hypoxic-ischemic neonatal encephalopathy.

ObjectiveTo define similarities and differences between neonatal arterial ischemic stroke (NAIS) and hypoxic‐ischemic neonatal encephalopathy (HINE).MethodsA retrospective case‐control study was conducted of neonates born at 35 weeks or more and weighing 1800 g or more at a tertiary care university hospital, between 2005 and 2016, with NAIS (group A), perinatal asphyxia (PA) with Stage II–III HINE (group B), and PA with or without Stage I HINE (group C). Ante‐ and intrapartum data, neonatal characteristics, and placental histopathology were compared.ResultsEleven neonates were identified in group A, 10 in group B, and 227 in group C. Sentinel events occurred exclusively in groups B (80%) and C (41.4%). Umbilical cord blood gas values and Apgar score were worse in groups B and C compared to group A. No group A neonates required resuscitation at birth, whereas all group B and one‐third of group C neonates did. Seizures developed only in neonates in groups A and B. One neonatal death occurred in group A. There were no significant differences in placental histopathology.ConclusionNAIS and PA/HINE cases have different intrapartum and neonatal features. PA does not seem necessary for the occurrence of NAIS. More research is needed regarding associated placental abnormalities.

The Effect of Maternal Pulmonary Function Test Parameters on Umbilical Cord Blood Gas and the Duration of Labor.

To evaluate the relationship between the maternal pulmonary function test (PFT) and the Apgar score of the newborn, umbilical cord blood (UCB) gas values and the duration of delivery. The present study included 41 volunteer nulliparous pregnant women who presented to our obstetrics clinic and PFTs were performed by using spirometry. A significant positive correlation was observed between 5th-minute Apgar scores and maternal FEV1 (forced expiratory volume in the first second) (lt), FEV1%, FVC (lt), FVC% (r=0.509, p=0.003; r=0.47, p=0.007; r=0.434, p=0.013; r=0.417, p=0.017; respectively). A significant positive correlation was observed between UCB pH value and maternal FEV1 (lt), FVC (lt) (r=0.515, p=0.003; r=0.351, p=0.049; respectively). Our results showed that FEV1 and FVC values, which indicate maternal respiratory functions, may affect Apgar scores of the newborn and UCB gas values.

Comparison between the Effects of Thiopental Sodium and Propofol on Maternal Hemodynamics during Cesarean Section Under General Anesthesia and Apgar score of the newborns

Abstract Background Cesarean delivery is one of the most current surgeries in women and one of the most significant challenges of anesthesiologists in this kind of surgery is the fetuses' exposure to anesthetic drugs. Regional anesthesia is generally preferred during cesarean section, but general anesthesia may be the only option under certain circumstances such as patient preference, back deformities. The most common drugs which are used in cesarean section to induce general anesthesia are thiopental sodium and propofol. Aim compare the effect of sodium thiopental induction versus propofol induction on hemodynamics of mothers undergoing elective cesarean section under general anesthesia and their effect on Apgar score of their newborns. Materials and Methods A total 260 healthy patients were included in an open randomized study, among whom 130 patients received Thiopentone and 130 received Propofol. These patients were premedicated with granisetron and ranitidine, after induction dose the maintenance was similar for both groups. APGAR scoring and umbilical cord venous gas analysis were among the parameters used for determining the general well-being of newborns. There were no significant difference between the two groups regarding Apgar scoring in 1st, 2nd and 5th minutes. Umbilical cord blood gas values were similar . There was no metabolic acidosis in newborns of mothers receiving thiopental or propofol as anesthetic agents during cesarean section. Results Group (T) received general anesthesia with thiopental at a dose of ( 4-6 mg/kg) while patients in group (P) received general anesthesia with propofol at a dose of (2mg/kg). As regards hemodynamic changes, there were no significant difference in maternal heart rate, systolic blood pressure, diastolic blood pressure and mean blood pressure during their measurement throughout the procedure-preoperatively, after delivery of the baby,15 minutes after delivery, after extubation and in recovery room- but after intubation, there were significantly lower in propofol group which suppressed hemodynamic response to intubation . Conclusion Thiopental and propofol can be safely used in cesarean sections, but the use of propofol is more advantageous than thiopental because it provides adequate anesthetic suppression of pressor response of intubation without any depressive effect on newborns.

Addition of dexmedetomidine to epidural morphine to improve anesthesia and analgesia for cesarean section.

The aim of the present study was to evaluate the effectiveness and safety of the combination of epidural dexmedetomidine and morphine in providing anesthesia during cesarean surgery and analgesia for post-cesarean pain relief when added to epidural ropivacaine. A total of 80 females at term scheduled for elective cesarean delivery were randomly assigned to two groups (n=40/group): In the morphine group (group M), patients received an epidural injection of 0.75% ropivacaine (12 ml) and morphine (2 mg) for surgical anesthesia, and epidural infusion of morphine (2 mg) in 100 ml 0.2% ropivacaine at 2 ml/h for 48-h post-operative analgesia; and in the morphine combined with dexmedetomidine group (group DM), patients received an epidural injection of 0.75% ropivacaine (12 ml) and morphine (2 mg) combined with dexmedetomidine (0.5 µg/kg) for surgical anesthesia, and epidural infusion of morphine (2 mg) and dexmedetomidine (200 µg) in 100 ml 0.2% ropivacaine at 2 ml/h for 48-h post-operative analgesia. The primary outcomes included blockade and analgesic effects, sedation and adverse reactions associated with the drugs. Neonatal outcome was also assessed by determining the Apgar score and umbilical cord blood analysis. There was no significant difference between the groups in the cephalad levels of sensory blockade at 20 min post-injection, or in muscle relaxation scores or pain intensity scores at rest or upon movement at 4, 12, 24 or 48 h post-injection (P>0.05). The maternal patients in the DM group experienced more complete motor blockade at 20 min post-injection, better sedation during surgery and following delivery, and less visceral pain caused by peritoneal traction during surgery and by uterine contraction after delivery, compared with those in group M (P<0.05). The patients in group M had a lower incidence and severity score of post-operative nausea than those in the DM group (P<0.05). There was no significant difference between the groups in terms of Apgar score or umbilical cord blood gas values (P>0.05). In conclusion, epidural dexmedetomidine reduces intra-operative and post-operative visceral pain and produces better sedation during surgery and following delivery, without any significant influence on morphine-associated side effects and post-operative analgesia, in females undergoing elective cesarean section under epidural anesthesia with morphine and ropivacaine (registration number ChiCTR1900027942; retrospectively registered with the Chinese Clinical Registry Center on December 6, 2019).

Comparison of Effects of General Anesthesia and Combined Spinal/Epidural Anesthesia for Cesarean Delivery on Umbilical Cord Blood Gas Values: A Double-Blind, Randomized, Controlled Study.

BackgroundThe objective of this study was to analyze the effects of general anesthesia in cesarean section on the umbilical cord blood gas values and intraoperative hemodynamics of parturient women.Material/MethodsA total of 112 parturient women who received cesarean section were eventually randomized into 2 groups, GA (general anesthesia) group (n=56), and SE (combined spinal and epidural anesthesia) group (n=56). The umbilical cord blood gas values, postpartum Apgar score, intraoperative blood loss, mean arterial pressure, heart rate, total operative time, time intervals from anesthesia to delivery and from skin incision to delivery, the incidences of adverse reactions and neonatal asphyxia, and the postoperative patient satisfaction were compared between the 2 groups.ResultsThere were no significant differences between the 2 groups in total operative time, Apgar score, neonatal asphyxia rate, umbilical arterial and venous cord blood gas values, intraoperative blood loss, and time interval from skin incision to delivery (all P>0.05). The GA group was significantly shorter in the time interval from anesthesia to delivery than the SE group (P<0.05). The incidences of nausea, vomiting, and chills in the GA group were significantly lower than those in the SE group (all P<0.05). The GA group was significantly higher in postoperative patient satisfaction than the SE group (P<0.05).ConclusionsGeneral anesthesia has little impact on the umbilical cord blood gas values and Apgar score, and ensures better hemodynamic stability in cesarean section. Moreover, general anesthesia is characterized by rapid induction and is therefore valuable for use in clinical procedures.

Examination of the Relationship between Umbilical Cord Blood Gas Values and Hearing Function in Neonates.

The aim of the present study was to examine the relationship between the results of the transient otoacoustic emission (TEOAE) test used in neonatal hearing screening and the results of the umbilical cord blood (UCB) analysis in neonates. This retrospective study included 209 neonates born in the obstetric unit at the 37th gestational week. Based on the results of the TEOAE test, the neonates included in the study were divided into two groups as the study group composed of those "REFER" (n=141) and the control group consisting those "PASS" (n=68) the test. The UCB sampling procedure was performed on all neonates. In the blood samples, the pH parameters were evaluated by using glass electrodes, and the pCO2 and pO2 parameters were evaluated directly by using sensitive electrodes. When the additional maternal diseases were compared with the TEOAE results, the ratio of hypothyroidism was found to be statistically higher in the study group (p<0.05). In terms of the pO2, pCO2, HCO3, and pH values obtained as a result of analyzing the UCB samples, there was no statistically significant difference between the groups (p>0.05). The results of the present study showed that there was no statistically significant difference between the results of UCB analysis and the TEOAE test. However, we believe that conducting a larger study evaluating other parameters and employing UCB analysis would be useful, and UCB evaluation, which is an inexpensive, easy and effective method in determining hypoxia in neonates, might be a significant marker in cases at risk of hearing loss.

Newborn outcomes in british columbia after caesarean section for non-reassuring fetal status.

To assess the incidence in British Columbia of severe morbidity in neonates delivered by Caesarean section for non-reassuring fetal status, and to examine the accuracy of Apgar score and umbilical cord gas values in predicting severe neonatal morbidity. We assessed rates of hypoxic ischemic encephalopathy, NICU admission, and ventilator days, individually and as a composite outcome with neonatal death, among a total of 8466 term singletons delivered by Caesarean section for non-reassuring fetal status between January 1, 2007, and December 31, 2011. We calculated the predictive accuracy of Apgar scores and umbilical cord blood gas values using the area under the receiver operating characteristic (ROC) curve and the sensitivity and specificity for each outcome. The incidence of Apgar score at one minute < 4 was 8.0%, and for Apgar score at five minutes < 4 it was 0.6%. The incidence of umbilical cord pH < 7.10 was 6.5%, and for base-excess < -12 it was 2.9%. Apgar score at one minute < 7 had the greatest predictive accuracy for the composite outcome (81% for both sensitivity and specificity). The area under the ROC curve for Apgar score at one minute and at five minutes, umbilical cord pH, and base-excess was 0.87, 0.86, 0.76, and 0.78, respectively. The incidence of abnormal Apgar score and abnormal umbilical cord gas values is very low among neonates in British Columbia delivered by Caesarean section for non-reassuring fetal status. Apgar score at one minute < 7 is a good predictor of severe neonatal morbidity. Electronic fetal monitoring remains a non-specific method for detection of fetal compromise in the intrapartum period.

PO-0725e Cerebral Tissue Oxygenation At Birth In Term Infants: Comparison Between Early And Late Cord Clamping

Background and aims The aim of our study is to compare the postnatal cerebral tissue oxygenation values in babies with early versus late cord clamping born after elective C/S. Methods In this prospective, observational study, we included term newborns delivered by elective C/S. Babies were segregated into two groups as early (within 15 seconds) and late cord clamping (at 60th seconds). Peripheral arterial oxygen saturation (SpO 2 ) and heart rate were measured using pulse oximetry (Nellcor N200) and regional oxygen saturation of the brain (rSO 2 brain) were measured (Invos 5100) between the 3rd and15th minutes and recorded every minute. Fractional tissue oxygen extraction (FTOE) was calculated for each minute (FTOE=pulse oximetry value-rSO 2 /pulse oximetry value). The measurements were compared for both groups. Results The demographical characteristics, SpO 2 levels, heart rates and umbilical cord blood gas values were not significantly different between the groups (p > 0.05). Cerebral oxygenation measurements and FTOE values were significantly higher for each minute in the late cord clamping group (p 2 was faster and the rSO 2 plateau was reached earlier in the late cord clamping group (Figure). Conclusions In our study we found that rSO 2 brain measurements and FTOE values were higher in the late cord clamping group without the need for any therapy as a result of high bilirubin and hematocrit levels.

Umbilical cord blood acid-base status in pregnancy with congenital heart disease.

The risk of fetal and neonatal complications is higher in pregnant women with congenital heart disease (CHD). It remains unknown whether umbilical cord blood gas values are different between pregnant women with CHD and healthy women undergoing elective cesarean section during combined spinal-epidural anesthesia. The purpose of the present study was to compare umbilical cord blood acid-base status and gas values in pregnant women with CHD vs. healthy pregnant women undergoing elective cesarean section during combined spinal-epidural (CSE) anesthesia. Patients with singleton pregnancy undergoing elective cesarean delivery under CSE anesthesia were enrolled. Patients were divided into two groups: healthy pregnant women (group H) and pregnant with congenital heart disease (group CHD). Immediately after delivery, umbilical cord arterial blood sample and venous blood sample were collected and measured. The comparison between two groups was performed using grouped t-test. Forty-four women in group H and 33 women in group CHD were analyzed finally. Umbilical arterial blood pH, base excess (BE) and HCO3 (-) (pH 7.29 ± 0.05, BE -1.4 ± 1.9 mmol/L, HCO3 (-) 21.5 ± 1.4 mmol/L) were significantly lower in pregnant women with CHD than in healthy pregnant women (pH 7.33 ± 0.03, BE -0.1 ± 2.1 mmol/L, HCO3 (-) 22.5 ± 1.4 mmol/L). The lower values of umbilical arterial blood pH, BE and HCO3 (-) were observed in pregnant women with CHD than in healthy women undergoing elective cesarean section during CSE anesthesia.

A Randomized Controlled Trial of Variable Rate Phenylephrine Infusion With Rescue Phenylephrine Boluses Versus Rescue Boluses Alone on Physician Interventions During Spinal Anesthesia for Elective Cesarean Delivery

Phenylephrine infusion is used to reduce hypotension during spinal anesthesia for cesarean delivery. A prophylactic fixed rate infusion regimen may not improve hemodynamic control; a variable rate regimen adjusted in response to changes in arterial blood pressure and heart rate may allow more accurate maintenance of baseline blood pressure. We hypothesized that a combination of crystalloid solution coload with a variable rate phenylephrine infusion and phenylephrine rescue boluses may be associated with fewer physician interventions needed to maintain maternal systolic blood pressure within 20% of baseline and greater hemodynamic stability than crystalloid solution coload with phenylephrine rescue boluses alone. In this prospective, double-blind study, 80 patients received a coload with 15 mL/kg lactated Ringer's solution immediately after the initiation of spinal anesthesia. Patients were randomized to receive a prophylactic variable rate phenylephrine infusion starting at 0.75 μg/kg/min (group P) or infusion of normal saline (group S). Maternal systolic blood pressure was maintained within 20% of baseline with rescue phenylephrine boluses using a preset algorithm. During the predelivery period, the number of physician interventions (primary outcome), hemodynamic performance, nausea/vomiting, and umbilical cord blood gas values were compared between the groups. One patient from group S was excluded due to protocol violation. Therefore, group P included 40 patients and group S 39 patients. The median (range) number of physician interventions needed to maintain maternal hemodynamics within the target range (0 [0-6] vs 3 [0-9], difference in median: 3, 95% confidence interval of difference: 2-4) and incidence of hypotension (8/40 [20%] vs 35/39 [90%]) were lower in group P compared with group S (P < 0.001). Group P had a higher incidence of hypertension compared with group S (6/40 [15%] vs 0/39 [0%], P = 0.026). The median performance error was closer to baseline (P < 0.001) with a smaller median absolute performance error (P = 0.001) in group P versus group S. In group P, 4/40 (10%) patients had nausea/vomiting compared with 17/39 (44%) in group S (P = 0.001). The number needed to treat was 1.4 women to prevent 1 case of hypotension, and 3 women to prevent 1 case of nausea/vomiting; the rate of hypertension was 1 case per 6.7 women treated. Neonatal outcomes were not different between the 2 groups. Prophylactic variable rate phenylephrine infusion and rescue phenylephrine bolus dosing is more effective than relying on rescue phenylephrine bolus dosing with respect to limiting clinician workload and maternal symptoms during spinal anesthesia for cesarean delivery.

Effect of the umbilical cord blood acid‐base status and gas values on the yield of mononuclear cells and CD34+ cells

To investigate the influence of umbilical cord blood (CB) acid-base status and gas values on the yield of mononuclear cells and CD34⁺ cells, pH, pCO₂, pO₂, HCO₃⁻ and base excess were measured in arterial CB samples obtained from normal full-term deliveries. The relationship of these values with the yield of mononuclear cells and CD34⁺ cells detected in venous CB was analyzed. A total of 145 CB units were collected from full-term vaginal deliveries at a single hospital. Immediately after delivery, a segment of the umbilical cord was double clamped, and arterial CB was analyzed to determine the acid-base status and gases. Venous CB was collected in a sterile collection bag and processed for cell separation within 24 h of collection. The relationship between umbilical arterial acid-base status, each gas value, and the yield of mononuclear cells and CD34⁺ cells was analyzed. Statistically significant correlations were observed between the net weight of CB and the total mononuclear and CD34⁺ cell counts. In addition, there was a negative correlation between the mononuclear cell counts and pH, but a positive correlation between the mononuclear cell counts and pCO₂. However, no significant differences were observed between the primipara and multipara groups in terms of the net weight of CB, total mononuclear cell counts and total CD34⁺ cell counts. The findings of the present study show that the mononuclear cell counts are correlated with arterial CB pH and pCO₂, suggesting the involvement of fetal hypoxia on the yield of mononuclear cells.

Evaluation of selection criteria for validating paired umbilical cord blood gas samples: an observational study

To compare six validation criteria for umbilical cord blood gas (UCBG) values in vigorous and nonvigorous neonates. Retrospective cohort study. Single tertiary obstetric centre, King Edward Memorial Hospital (KEMH), Perth, Western Australia. A total of 37,763 consecutive deliveries at >23 weeks of gestation. Six validation criteria were compared to evaluate the proportion of deliveries with 'valid' UCBG data; and the proportion of vigorous and nonvigorous neonates with metabolic acidaemia. Proportion of deliveries with 'valid' UCBG values; proportions of vigorous and nonvigorous neonates with normal, borderline and abnormal UCBG values. The criteria based on KEMH 5th centile arteriovenous pH and Pco(2) differences resulted in a higher proportion of neonates with 'valid' UCBG values than the previously described Westgate and Kro criteria. The increase in 'valid' UCBG values occurred across the entire study population including vigorous and nonvigorous neonates. Among neonates with short-term neonatal complications there was an increase in nonvigorous neonates with umbilical artery metabolic acidaemia. There was no corresponding increase in vigorous neonates diagnosed with abnormal UCBG values. Use of the KEMH criteria results in an increase in the proportion of nonvigorous term neonates with UCBG data considered 'valid' to aid clinicians in the management of the neonate shortly after delivery. This change occurs without increasing the rate of false-positive diagnoses of acidaemia in vigorous neonates. The KEMH 'validation' criteria were developed from an entire presenting population and provide a simple algorithm that can be universally applied to identify neonates with nonphysiological UCBG values.

SP6-28 Effect of umbilical cord blood acid-base status and gas values on the yield of mononuclear cells and cd34 cells

PurposeTo investigate the influence of umbilical cord blood (CB) acid-base status and gas values on the yield of mononuclear cells and CD34 cells, pH, pCO2, pO2, HCO3− and base excess...

The Effects of Crystalloid and Colloid Preload on Cardiac Output in the Parturient Undergoing Planned Cesarean Delivery Under Spinal Anesthesia: A Randomized Trial

Hypotension after spinal anesthesia for cesarean delivery remains a major clinical problem. Fluid preloading regimens together with vasopressors have been used to reduce its incidence. Previous studies have used noninvasive arterial blood pressure measurement and vasopressor requirements to evaluate the effect of preload. We used a suprasternal Doppler flow technique to measure maternal cardiac output (CO) and corrected flow time (FTc, a measure of intravascular volume) before and after spinal anesthesia after 3 fluid preload regimens. We hypothesized that colloid solutions, compared with crystalloid, would produce the largest increase in CO and have the lowest incidence of hypotension. Sixty healthy term women scheduled for planned cesarean delivery under spinal anesthesia were recruited for this randomized, double-blind study. Baseline heart rate, systolic blood pressure (SBP), CO, and FTc were recorded in the left lateral tilt position. Patients were randomized to receive 1 of 3 fluid preload regimens given over 15 min: 1.5 L crystalloid (Hartman's solution), 0.5 L of 6% w/v hydroxyethyl starch (HES) solution (HES 0.5), or 1 L of 6% w/v HES solution (HES 1.0). Further measurements were made after fluid loading every 5 min for 30 min. After 30 min, spinal anesthesia was induced with hyperbaric bupivacaine 12.5 mg with fentanyl 15 microg and recordings were continued every 5 min for 20 min or until surgery started. The primary outcome, CO, was compared among groups. The incidence of hypotension (defined as a 20% reduction in SBP from the baseline), ephedrine use, and umbilical cord blood gases were also compared. Patient characteristics, heart rate, SBP, and cord gases were similar among groups. Although CO and FTc increased after preload in all groups (P < 0.005), this was only maintained with HES 1.0 after spinal anesthesia (P < 0.005). There were no differences among groups in the incidence of hypotension (70% vs 35% vs 65% for Hartman's solution, HES 0.5, and HES 1.0, respectively; P = 0.069) or mean ephedrine dose (10.4 vs 5.7 vs 9.7 mg; P = 0.26). Despite CO and FTc increases after fluid preload, particularly with HES 1.0 L, hypotension still occurred. The data suggest that CO increases after these preload regimens cannot compensate for reductions in arterial blood pressure after spinal anesthesia.