Anesthetic and obstetric outcomes in morbidly obese parturients: a 20-year follow-up retrospective cohort study

BackgroundIn 1993, Hood and Dewan published the results of a trial comparing obstetric and anesthetic outcomes of 117 morbidly obese parturients with matched controls. The authors demonstrated a higher initial epidural anesthesia failure rate, a higher cesarean delivery rate and an increased risk of obstetric complications. We replicated the previous study to provide updated information on outcomes in the morbidly obese pregnant population. We hypothesized that morbidly obese women would still have higher complication and failure rates compared to matched controls and that general anesthesia would be less commonly used than in the previous study.MethodsThe medical records of 230 patients weighing >136 kg (300 pounds) were compared to matched controls: the next patient delivered by the same obstetrician with a weight <113 kg (250 pounds).ResultsThe mean weight of the morbidly obese group was 53.4 ± 6.6 kg/m² compared to 31.1 ± 5.4 kg/m² in the control group. Fifty percent of morbidly obese women required cesarean delivery compared to 32% of controls (P <0.01). Morbidly obese patients had a longer first stage of labor (P <0.01), larger neonates (P <0.01), and were more likely to have a failed initial neuraxial technique for labor analgesia (P <0.01). The need for a replacement procedure for labor was 17%, significantly less than 20 years ago when 42% of catheters in morbidly obese women failed (P <0.01). Failure rates of neuraxial anesthesia for cesarean delivery were similar between groups. Neuraxial procedure times were greater in morbidly obese parturients (P <0.01). Morbidly obese women were less likely to receive general anesthesia compared to 20 years ago (3% vs. 24%, P <0.01).ConclusionsMorbidly obese parturients are still at increased risk for antenatal comorbidities, failed labor analgesia, longer first stage of labor and operative delivery. Replacement labor epidural catheters and general anesthesia for cesarean delivery are less commonly required anesthetic techniques compared to the original study.     

Serum uric acid as a novel marker for uterine atony and post-spinal vasopressor use during cesarean delivery

IntroductionSerum uric acid is a marker for oxidative stress in preeclampsia. Because oxidative stress can result in diminished uterine contractility and impaired vascular relaxation, we hypothesized that an elevated serum uric acid level in women undergoing neuraxial anesthesia for cesarean delivery would be associated with greater uterine atony, as measured by supplemental uterotonic agent use and blood loss, and less hypotension, as measured by total vasopressor use.MethodsAll records of patients (n = 2527) undergoing cesarean delivery in 2009 were reviewed. Serum uric acid was measured within 24 h of delivery in 509 patients; data from 345 patients with singleton pregnancies undergoing neuraxial anesthesia were analyzed. Demographic data, medical and obstetric history, anesthetic management and peripartum course were evaluated. ANOVA, Chi-square, and multivariate logistic and linear regression analyses were performed.ResultsIncreased serum uric acid correlated positively with preeclampsia and the need for supplemental uterotonic agents (odds ratio 1.53, 95%CI 1.2–2.0, P = 0.002), but not blood loss. The presence of preeclampsia also correlated with greater supplemental uterotonic agent use (P = 0.01). The correlation between serum uric acid and post-spinal vasopressor use (i.e., none, moderate, and high) was of borderline significance (P = 0.05). In patients without diabetes, serum uric acid levels correlated inversely with post-spinal vasopressor use (P = 0.04).ConclusionsElevated serum uric acid in parturients undergoing cesarean delivery with neuraxial anesthesia correlated with increased use of supplemental uterotonic agents and decreased use of post-spinal vasopressors. Further validation of this study is required to determine if serum uric acid in parturients can serve as a reliable predictor for higher and lower occurrences of uterine atony and spinal-induced hypotension, respectively.     

Pencil-point needle bevel direction influences ED50 of isobaric ropivacaine with fentanyl in spinal anesthesia for cesarean delivery: a prospective,double-blind sequential allocation study

BackgroundThere is little evidence on the influence of bevel direction of a pencil-point needle on the median effective dose (ED50) of isobaric ropivacaine and fentanyl in spinal anesthesia for cesarean delivery.MethodsIn this prospective, double-blind, sequential allocation study, 82 parturients scheduled for elective cesarean delivery under combined spinal-epidural anesthesia were included. We sought to determine the median effective dose of intrathecal 0.75% isobaric ropivacaine plus fentanyl 15 μg with two different bevel directions of a 26-gauge Whitacre needle using up-down sequential allocation. Parturients were randomly allocated to either Group Ce (needle aperture oriented in a cephalad direction) or Group Ca (aperture directed caudally). The initial dose was 0.75% ropivacaine 11.25 mg plus fentanyl 15 μg in both groups. Each dose was classified as effective if, after 15 min and during the next 60 min, there was inability to appreciate pin-prick as sharp at T4, a visual analogue pain score <2 and no requirement for an epidural rescue bolus.ResultsEighty patients were included in the analysis. The ED50 in group Ca was significantly higher (13.09 mg, 95% CI 12.19–14.00) than in group Ce (10.10 mg, 95% CI 9.54–10.65, P <0.001).ConclusionThe orientation of the distal aperture of a 26-gauge Whitacre needle during induction of spinal anesthesia for cesarean delivery influences the ED50 of 0.75% ropivacaine.     

Role of pleth variability index for predicting hypotension after spinal anesthesia for cesarean section

BackgroundHypotension is frequently observed after spinal anesthesia for cesarean section and can be detrimental to both mother and baby. We investigated the role of the pleth variability index for predicting hypotension after spinal anesthesia for cesarean section.MethodsEighty-five parturients undergoing elective cesarean section under spinal anesthesia were enrolled. We recorded pleth variability index and perfusion index before anesthesia, and blood pressure, heart rate and pulse oxygen saturation before and after anesthesia. The association between baseline pleth variability index and perfusion index with hypotension after spinal anesthesia was explored using multivariate analysis.ResultsHypotension occurred in 42 parturients. Baseline pleth variability index was higher in parturients who experienced hypotension than in those who did not (P < 0.05), although there was no difference in baseline perfusion index. The area under the receiver operating characteristic curve was 0.66 for baseline pleth variability index for the prediction of hypotension (P < 0.05). Baseline pleth variability index was significantly related to the incidence of hypotension (P = 0.017), but was not significantly related to the magnitude of the decrease in systolic blood pressure. Baseline perfusion index was not significantly related to the magnitude of the decrease in systolic blood pressure.ConclusionGreater baseline pleth variability index was associated with hypotension after spinal anesthesia for cesarean section, but may not be a clinically useful predictor.     

Assessment of endothelial glycocalyx disruption in term parturients receiving a fluid bolus before spinal anesthesia: a prospective observational study

BackgroundFluid bolus administration is a standard treatment for hypotension. However, the effectiveness of the traditional prophylactic bolus in parturients undergoing spinal anesthesia for cesarean delivery has been questioned. One potential mechanism for the failure of a prophylactic fluid bolus to prevent hypotension is hypervolemia-induced destruction of the endothelial glycocalyx, a structure that plays a vital role in regulating intravascular fluid shifts.MethodsThirty healthy parturients undergoing elective cesarean delivery under spinal anesthesia were recruited. Known endothelial glycocalyx biomarkers, heparan sulfate and syndecan-1 along with atrial natriuretic peptide, were measured before and after a 750-mL crystalloid fluid bolus. Cardiac performance parameters, cardiac index and systemic vascular resistance, were monitored during the fluid bolus using thoracic-impedance cardiography.ResultsA significant increase in both heparan sulfate 96 ng/mg (P=0.0098) and syndecan-1 2.4 ng/mg (P=0.045) were observed after the fluid bolus. There was a non-significant increase in atrial natriuretic peptide 0.6 pg/mg (P=0.293). Cardiac parameters showed a small but significant change; over an average of 15 min, cardiac index increased by 0.1 L/min/m² (P=0.0005) and systemic vascular resistance decreased by 30.7 dyn.s/cm⁵ (P=0.0025).ConclusionsA prophylactic fluid bolus in parturients undergoing spinal anesthesia for cesarean delivery disrupts the endothelial glycocalyx, as noted by a statistically significant increase in post-bolus heparan sulfate and syndecan-1 levels. Although studied in the past, atrial natriuretic peptide could not explain this disruption. Our fluid bolus did not have a clinically relevant effect on cardiac performance.     

Effects of intravenous ondansetron and granisetron on hemodynamic changes and motor and sensory blockade induced by spinal anesthesia in parturients undergoing cesarean section

BackgroundSpinal anesthesia has many advantages for cesarean section parturients, but hypotension is considered the most frequent complication and can be managed by different interventions. One of these interventions is to give a serotonin receptor antagonist prior to spinal anesthesia.ObjectivesTo compare between two serotonin receptor antagonists on the hemodynamics, sensory, and motor blockade induced by intrathecal bupivacaine in parturients undergoing cesarean section.Patients and methodsSixty patients undergoing elective cesarean section under spinal anesthesia by intrathecal bupivacaine were randomly divided into three groups (20 pregnant females of ASA I–II physical status in each group). Group O received intravenous 4 mg ondansetron diluted in 10 ml normal saline and injected over 1 min, 5 min before spinal anesthesia, group G given intravenous 1 mg granisetron by the same route and group S given 10 ml normal saline. Mean arterial blood pressure, heart rate, vasopressor use, sensory, and motor blockade were assessed.ResultsDecreases in mean arterial pressure were significantly lower in group O than groups G and S with lower vasopressor use (P < 0.05), while there was significant faster sensory recovery in group G than groups O and S (P < 0.05). Actually, there were significant decrease in the incidence of nausea in groups O and G than group S (P = 0.008).ConclusionIn parturient females undergoing elective cesarean section, intravenous 4 mg ondansetron before subarachnoid block significantly decreased both the hypotension and the doses of vasopressor used, while intravenous 1 mg granisetron prior to subarachnoid block induced faster sensory recovery compared to both the ondansetron and the saline groups, with no significant differences between the later two groups.     

A randomized study of maternal serum cytokine levels following cesarean section under general or neuraxial anesthesia

BackgroundCytokines are significant mediators of the immune response to surgery and also play a role in parturition. The aim of the study was to investigate the impact of the anesthetic technique for cesarean section on plasma levels of cytokines IL-6 and TNF-α.MethodsThirty-five parturients scheduled for elective cesarean section were randomly assigned to general (n = 18) or neuraxial (n = 17) anesthesia. The general anesthesia group received thiopental 4 mg/kg, succinylcholine 1–1.5 mg/kg and 1% end-tidal concentration of sevoflurane in nitrous oxide and 50% oxygen. The neuraxial anesthesia group received intrathecal 0.5% levobupivacaine 1.8–2.2 mL and epidural fentanyl 1 μg/kg. Blood samples were taken for IL-6 and TNF-α immediately after positioning the parturient on the operating table, after uterine incision and before the umbilical cord clamping and 24 h after surgery (T₁, T₂ and T₃ respectively).ResultsThe two groups did not differ in IL-6 (P = 0.15) or TNF-α (P = 0.73) serum concentrations at any time point. In the general and neuraxial anesthesia groups, IL-6 serum concentrations were significantly higher in the third blood sample, T₃ (12.2 ± 5.0 and 15.2 ± 4.3 pg/mL), than in T₁ (0.41 ± 0.38 and 0.29 ± 0.10 pg/mL) and T₂ (0.37 ± 0.47 and 0.24 ± 0.05) respectively (P < 0.001). Within each group, serum TNF-α concentrations did not differ significantly over time (P = 0.44).ConclusionsUnder the present study design anesthetic technique did not affect IL-6 or TNF-α concentrations in parturients undergoing elective cesarean section. Serum IL-6 levels increased 24 h postoperatively independently of anesthetic technique.     

Neuraxial opioids for post-cesarean delivery analgesia: can hydromorphone replace morphine? A retrospective study

BackgroundCesarean delivery is the most common surgical procedure performed in the USA. We evaluated the postoperative analgesic properties of neuraxial hydromorphone compared to neuraxial morphine for post-cesarean delivery analgesia.MethodsA retrospective chart review was performed of women who underwent cesarean delivery and received neuraxial anesthesia from March to November 2011 and from March to November 2012. A total of 450 patients received intrathecal morphine 200 μg and 387 patients received intrathecal hydromorphone 60 μg. Eighty-one patients received epidural morphine 3 mg and 102 patients received epidural hydromorphone 0.6 mg.ResultsMedian time to first opioid after intrathecal morphine was 17.0 h versus 14.6 h after intrathecal hydromorphone (P <0.0001). Patients who received intrathecal hydromorphone consumed more opioids in the first 24 h; 37.0 mg versus 26.4 mg oral morphine equivalents (P <0.001). The side effect profile between the intrathecal groups was similar. Median time to first opioid with epidural morphine was 20.1 h versus 13.0 h with epidural hydromorphone (P=0.0007). Total opioid consumption was not significantly different between the epidural groups. The side effect profiles were similar.ConclusionsHydromorphone is a reasonable alternative to morphine for post-cesarean delivery analgesia. With the dosing used in our study, analgesia from morphine lasted longer than hydromorphone via intrathecal and epidural routes; however, neuraxial hydromorphone remains a reasonable option for long-acting analgesia post cesarean delivery.     

The impact of gestational age and fetal weight on the risk of failure of spinal anesthesia for cesarean delivery

BackgroundThere are limited data about spinal dosing for cesarean delivery in preterm parturients. We investigated the hypothesis that preterm gestation is associated with an increased incidence of inadequate spinal anesthesia for cesarean delivery compared with term gestation.MethodsWe searched our perioperative database for women who underwent cesarean delivery under spinal or combined spinal-epidural anesthesia with hyperbaric bupivacaine ⩾10.5 mg. The primary outcome was the incidence of inadequate surgical anesthesia needing conversion to general anesthesia or repetition or supplementation of the block. We divided patients into four categories: <28, 28 to <32, 32 to <37 and ⩾37 weeks of gestation. The chi-square test was used to compare failure rates and a multivariable regression analysis was performed to investigate potential confounders of the relationship between gestational age and failure.ResultsA total of 5015 patients (3387 term and 1628 preterm) were included. There were 278 failures (5.5%). The incidence of failure was higher in preterm versus term patients (6.4% vs. 5.1%, P=0.02). Failure rates were 10.8%, 7.7%, 5.3% and 5% for <28, 28 to <32, 32 to <37 and ⩾37 weeks of gestation, respectively. In the multivariable model, low birth weight (P<0.0001), gestational age (P=0.03), ethnicity (P=0.02) and use of combined spinal-epidural anesthesia (P<0.0001) were significantly associated with failure.ConclusionsAt standard spinal doses of hyperbaric bupivacaine used in our practice (⩾10.5 mg), there were higher odds of inadequate surgical anesthesia in preterm parturients. When adjusting for potential confounders, low birth weight was the main factor associated with failure.     

Parturients with hypertrophic cardiomyopathy: case series and review of pregnancy outcomes and anesthetic management of labor and delivery

BackgroundAdvances in understanding the pathogenesis, diagnosis and management of hypertrophic cardiomyopathy have resulted in increased longevity and a better quality of life of affected patients considering pregnancy. Several case series which focused predominantly on obstetric details have reported generally good outcomes. However, there remains a paucity of data on the specifics of obstetric anesthesia in women with hypertrophic cardiomyopathy.MethodsAfter Institutional Review Board approval, we reviewed antepartum transthoracic echocardiograms, cardiology, obstetric, anesthetic, and nursing labor records with a focus on anesthesia for labor and delivery and early postpartum complications in patients with hypertrophic cardiomyopathy who delivered between January 1993 and December 2013.ResultsThere were 23 completed pregnancies in 14 patients: 12 parturients (52%) delivered vaginally, of whom seven (30%) required assistance (forceps, vacuum), and 11 (48%) had a cesarean delivery. In 17 cases (74%) delivery was uneventful, but six patients (26%) had complications including congestive heart failure (n=3) and postpartum hemorrhage (n=3). All patients had neuraxial labor anesthesia/analgesia, and none received general anesthesia. No hemodynamic instability or fetal distress directly related to anesthesia was documented.ConclusionThe database search of approximately 160 000 deliveries over 20 years revealed only a small number of hypertrophic cardiomyopathy patients with completed pregnancies. No maternal or neonatal deaths were documented. Overall morbidity rate was 26% with a 13% incidence of peripartum congestive heart failure. In patients with mild to moderate disease, neuraxial anesthesia was safe, effective and well tolerated with no hemodynamic instability related to administration of local anesthetics.     

Preoperative anterior thigh temperature does not correlate with perioperative temporal hypothermia during cesarean delivery with spinal anesthesia: Secondary analysis of a randomized control trial

BackgroundCore-to-peripheral redistribution of heat, secondary to sympathetic-mediated vasodilation, is the major mechanism leading to early perioperative hypothermia after neuraxial anesthesia. The study aim was to determine if preoperative anterior thigh (peripheral lower extremity) temperature predicted perioperative temporal (core) temperature decrease during cesarean delivery with spinal anesthesia.MethodsSecondary analysis of data derived from a prospective, randomized study of 46 healthy women undergoing scheduled cesarean delivery with spinal anesthesia was performed. Anterior thigh temperature was measured preoperatively prior to spinal anesthesia. The primary outcome was maximum perioperative temporal temperature decrease. Secondary outcomes included incidence of temporal hypothermia (temperature <36°C), shivering, and thermal comfort scores. This study ran concurrently with a previously published trial comparing no active intraoperative warming with active warming.ResultsThere was no correlation between preoperative anterior thigh temperature and maximum perioperative temporal temperature decrease (r=−0.049, P=0.751). The mean ± standard deviation preoperative anterior thigh temperature of women who developed temporal hypothermia compared to those who did not was 32.4 ± 0.8°C versus 32.4 ± 0.70°C respectively (P=0.995). Preoperative anterior thigh temperature did not correlate with the incidence of shivering (r=0.267, P=0.080) or thermal comfort scores (r=0.233, P=0.129).ConclusionPreoperative anterior thigh temperature does not correlate with the degree of perioperative temporal temperature decrease, likelihood of developing hypothermia, shivering, or thermal comfort during cesarean delivery with spinal anesthesia. Although core-to-peripheral redistribution of heat after neuraxial anesthesia is a major mechanism of perioperative heat loss, a lower extremity temperature prediction hypothesis was not confirmed in this population.     

An open-label randomized controlled clinical trial for comparison of continuous phenylephrine versus norepinephrine infusion in prevention of spinal hypotension during cesarean delivery

BackgroundDuring spinal anesthesia for cesarean delivery phenylephrine is the vasopressor of choice but can cause bradycardia. Norepinephrine has both β- and α-adrenergic activity suitable for maintaining blood pressure with less bradycardia. We hypothesized that norepinephrine would be superior to phenylephrine, requiring fewer rescue bolus interventions to maintain blood pressure.MethodsEighty-five parturients having spinal anesthesia for elective cesarean delivery were randomized to Group P (phenylephrine 0.1 μg/kg/min) or Group N (norepinephrine 0.05 μg/kg/min) fixed-rate infusions. Rescue bolus interventions of phenylephrine 100 μg for hypotension, or ephedrine 5 mg for bradycardia with hypotension, were given as required to maintain systolic blood pressure. Maternal hemodynamic variables were measured non-invasively.ResultsThere was no difference between groups in the proportion of patients who required rescue vasopressor boluses (Group P: 65.8% [n=25] vs. Group N: 48.8% [n=21], P=0.12). The proportion of patients who received ⩾1 bolus of phenylephrine was similar between groups (Group P: 52.6% [n=20] vs. Group N: 46.5% [n=20], P=0.58). However, more patients received ⩾1 bolus of ephedrine in the phenylephrine group (Group P: 23.7% [n=9] vs. Group N: 2.3% [n=1], P <0.01). The incidence of emesis was greater in the phenylephrine group (Group P: 26.3% vs. Group P: 16.3%, P <0.001). Hemodynamic parameters including heart rate, the incidence of bradycardia, blood pressure, cardiac output, cardiac index, stroke volume, and systemic vascular resistance and neonatal outcome were similar between groups (all P <0.05).ConclusionNorepinephrine fixed-rate infusion has efficacy for preventing hypotension and can be considered as an alternative to phenylephrine.     

The effect of co-administration of intravenous calcium chloride and oxytocin on maternal hemodynamics and uterine tone following cesarean delivery: a double-blinded,randomized, placebo-controlled trial

BackgroundOxytocin administration to prevent uterine atony following cesarean delivery is associated with adverse effects including hypotension, tachycardia, and nausea. Calcium chloride increases mean arterial pressure, systemic vascular resistance, and uterine smooth muscle contractility. This study evaluated whether the co-administration of calcium chloride with oxytocin following cesarean delivery could alter maternal hemodynamics. Secondary outcomes included uterine tone and blood loss.MethodsSixty healthy parturients with singleton, term, vertex pregnancies undergoing elective cesarean delivery under spinal anesthesia were randomized to one of three study solutions given intravenously immediately after umbilical cord clamping: (1) placebo, oxytocin 5 U alone; (2) CA-200, oxytocin 5 U + calcium chloride 200 mg; or (3) CA-400, oxytocin 5 U + calcium chloride 400 mg. Blood pressure, heart rate, uterine tone, vasopressor or alternate uterotonic use and the incidence of nausea or vomiting were recorded. Baseline and intraoperative plasma concentration of ionized calcium and hematocrit were measured.ResultsPlasma concentration of ionized calcium was elevated in both study groups compared with placebo (P=0.001). Blood pressure decreased and heart rate increased in all groups (P <0.0001), with no differences between groups. No differences were observed between groups in uterine tone, vasopressor use, hematocrit change, estimated blood loss, incision-to-delivery interval, delivery-to-skin closure interval, total intravenous fluid administered or incidence of nausea.ConclusionsThe decrease in blood pressure associated with oxytocin administration following cesarean delivery was not attenuated with co-administration of calcium chloride at the doses evaluated. Vasopressor use, uterine tone, and blood loss were also unaffected.     

O efeito de epinefrina,norepinefrina e fenilefrina no tratamento da hipotensão pós‐raquianestesia: estudo clínico comparativo

Background and objectivesLimited data are present on safety and efficiency of epinephrine for the prophylaxis and treatment of spinal‐hypotension. This study was conducted to compare the effect of epinephrine with norepinephrine and phenylephrine on the treatment of spinal‐hypotension and ephedrine requirement during cesarean delivery.MethodsOne hundred and sixty parturients with uncomplicated pregnancies undergoing elective cesarean delivery under spinal anesthesia were recruited. They were allocated randomly to receive norepinephrine 5 μg.mL^‐1 (n = 40), epinephrine 5 μg.mL^‐1 (n = 40), phenylephrine 100 μg.mL^‐1 (n = 40) or 0.9% saline infusions (n = 40) immediately after induction of spinal anesthesia. Whenever systolic blood pressure drops to less than 80% of baseline, 5 mg of iv ephedrine was administered as rescue vasopressor. The incidence of hypotension, total number of hypotension episodes, the number of patients requiring ephedrine, the mean amount of ephedrine consumption and side effects were recorded.ResultsThere was no statistically significant difference in incidence of maternal hypotension between groups. The number of patients requiring ephedrine was significantly greater in group saline than in group phenylephrine (p < 0.001). However, it was similar between phenylephrine, norepinephrine, and epinephrine groups. The mean ephedrine consumption was significantly higher in group saline than in norepinephrine, epinephrine, phenylephrine groups (p = 0.001).ConclusionThere is no statistically significant difference in incidence of hypotension and ephedrine consumption during spinal anesthesia for cesarean delivery with the use of epinephrine when compared to norepinephrine or phenylephrine. Epinephrine can be considered as an alternative agent for management of spinal hypotension.     

A comparative study of general anesthesia versus combined spinal–epidural anesthesia on the fetus in cesarean section

BackgroundObstetric anesthesia guidelines recommend regional over general anesthesia for most caesarean sections to decrease the risk for both fetus and mother.Aim of the workTo determine the effects of combined spinal epidural anesthesia and general anesthesia on the newborns and the mother undergoing elective cesarean section.SubjectsA total of 60 consecutive women with uncomplicated singleton pregnancies at term and scheduled to undergo elective cesarean section at Kasr Al-Aini obstetric hospital participated in this prospective study. The women were divided into 2 groups (each 30), a general anesthesia group (A) and combined spinal–epidural anesthesia group (B).MethodsUmbilical artery blood gas analysis and Apgar scores were assessed at 1 and 5 min after delivery in the newborn while systolic and diastolic blood pressure, heart rate, oxygen saturation and (capnography in general anesthesia) were measured preoperative and after 5, 10 and 15 min of induction of anesthesia in the mothers. In addition, the time from induction of anesthesia till delivery of the fetus and duration in operative room were measured.ResultsApgar score recorded statistically significant differences between the 2 groups at 1 min and 5 min, where with combined spinal–epidural anesthesia the Apgar score readings were higher than with general anesthesia. HCO₃ readings showed a statistically significant difference between the 2 groups after 1 and 5 min, where the newborns in general anesthesia group had a statistically significant lower HCO₃ compared to the newborns in combined spinal–epidural group. Patients in general anesthesia group were significantly more tachycardic compared to patients in combined spinal–epidural group.ConclusionCombined spinal–epidural anesthesia is safer on the newborn than general anesthesia regarding the APGAR scores and acid–base balance.     

Maternal sedation during scheduled versus unscheduled cesarean delivery: implications for skin-to-skin contact

BackgroundEarly maternal skin-to-skin contact confers numerous benefits to the newborn, but maternal sedation during cesarean delivery could have safety implications for early skin-to-skin contact in the operating room. We compared patient-reported and observer-assessed levels of sedation during unscheduled and scheduled cesarean deliveries.MethodsLaboring women undergoing unscheduled cesarean delivery with epidural anesthesia, and scheduled cesarean delivery with spinal anesthesia were enrolled. Sedation levels, measured using patient-reported (1=least sedated to 10=most sedated) and observer-assessed (0=most sedated to 5=least sedated) scales, were evaluated at baseline and 15, 30, 45, and 60 min following a T4 sensory level. The primary outcomes were patient-reported sedation at 45 min and the areas under the sedation curves.ResultsPatient-reported levels of sedation were greater at 45 min in laboring women undergoing unscheduled (median 7.5, IQR 5–9) versus scheduled cesarean delivery (median 4, IQR 3–6) (difference in medians 3.5, 99% CI 0 to 5). Observer-assessed sedation was not different between groups. The area under the time curve for patient-reported sedation was greater in the unscheduled group, median difference 162 score min (95% CI 52 to 255). The area under the time curve for observer-assessed sedation was greater in the unscheduled group, median difference 26 score min (99% CI 0 to 41). Times to skin-to-skin contact and breastfeeding were not different.ConclusionsWomen undergoing unscheduled cesarean deliveries are more sedated than women undergoing scheduled cesarean deliveries. Skin-to-skin protocols for cesarean deliveries must consider maternal sedation and anesthesiologists should use sedating medications judiciously.     

Effect of preoperative Mg sulfate infusion on serum cardiac troponin (cTn) in moderate preeclamptic undergoing elective cesarean section under spinal anesthesia

This study was designed to investigate and compare the effect of preoperative Mg sulfate infusion on serum cardiac troponin (cTn) in moderate preeclampsia undergoing elective cesarean section. A total of fifty parturients having moderate preeclampsia scheduled for elective cesarean section were included. They were randomly allocated into two equal groups 25 each, magnesium group (GMg) received preoperative magnesium sulfate infusion and control group (GC) then both received spinal anesthesia, serum troponin measured preoperative then at 6, 12 and 24 h postoperative. Mean arterial pressure and heart rate were also recorded. Baseline serum cardiac troponin was higher above normal and was comparable at the rest of times in both groups. Mean arterial pressure readings were significantly lower in GMg compared to GC at induction of spinal, skin incision and skin closure (P < 0.05) and were comparable at the rest of times. Serum cardiac troponin (cTn) levels were comparable in parturients received magnesium sulfate infusion preoperatively with those did not receive magnesium sulfate.     

Neonatal effects after vasopressor during spinal anesthesia for cesarean section: a multicenter,randomized controlled trial

BackgroundPlacental transfer of ephedrine causes fetal effects when compared with phenylephrine. This study compared their drug effects on neonatal parameters after cesarean delivery under spinal anesthesia.MethodsThree-hundred-and-fifty-four women undergoing elective cesarean delivery who needed intravenous vasopressor following spinal anesthesia were randomized into two groups. Group E received boluses of ephedrine 6 mg, and Group P phenylephrine 100 µg, titrated to maintain systolic blood pressure near baseline values. Neonatal heart rates at 10 and 30–45 min of age, oxygen saturation and capillary blood glucose at 30 min, and capillary blood lactate and urine metamphetamine were recorded.ResultsNeonatal heart rate at 10 min was significantly higher (mean difference 4.0, 95%CI 0.6 to 7.3, P=0.02) in Group E versus Group P, but this was not clinically relevant. There was a linear correlation between neonatal heart rate at 10 min and ephedrine dose in Group E (r²=0.29, 95%CI 0.22, 0.74, p <0.01). The decremental changes in neonatal heart rate at 10 and 30 min were significantly greater in Group E. Urine metamphetamine tests were positive in 19% of 44 neonatal urine samples. Neonatal heart rates at 30 min, oxygen saturation, capillary blood glucose and the incidence of tachycardia, respiratory problems or abnormal glucose, were not significantly different.ConclusionsEphedrine, compared to phenylephrine as a vasopressor during cesarean delivery, was associated with higher neonatal heart rate in the early post-birth period, but without a significant difference in clinical outcomes in uncomplicated pregnancies.     

A randomized comparison of onset of anesthesia between spinal bupivacaine 5 mg with immediate epidural 2% lidocaine 5 mL and bupivacaine 10 mg for cesarean delivery

BackgroundPrevious studies using low-dose spinal anesthesia for cesarean delivery have focused on hypotension and efficacy. This study evaluated whether, using a combined spinal–epidural technique, there was a difference in onset of anesthesia for cesarean delivery between low-dose spinal with an immediate epidural local anesthetic bolus, and conventional-dose spinal anesthesia.MethodsForty healthy term nulliparous women undergoing elective cesarean delivery with a combined spinal–epidural technique were enrolled into this prospective, randomized, double-blind study. Patients were randomly allocated to the low-dose (Group L) or conventional-dose group (Group C). Patients in Group L received intrathecal isobaric bupivacaine 5 mg with sufentanil 2.5 μg followed by epidural 2% lidocaine 5 mL; patients in Group C received intrathecal isobaric bupivacaine 10 mg with sufentanil 2.5 μg followed by epidural saline 5 mL. The onset of anesthesia (defined as the time from spinal injection to a block to T6), incidence of hypotension, maximal sensory block, epidural supplementation and side effects were recorded.ResultsAll blocks reached T6 within 11 min except for one patient in Group L. There were no differences in onset of anesthesia (9.9 ± 3.2 min in Group L vs. 8.5 ± 1.2 min in Group C, P = 0.08), maximal block level and the number of patients who required epidural supplementation in both groups. Hypotension occurred in 8 patients (40%) in Group L and 15 patients (75%) in Group C (P = 0.02).ConclusionsIntrathecal bupivacaine 5 mg with immediate 2% epidural lidocaine 5 mL provided comparable onset and efficacy of anesthesia as bupivacaine 10 mg with immediate epidural normal saline 5 mL for cesarean delivery.     

Pharmacokinetics of bupivacaine after bilateral ultrasound-guided transversus abdominis plane block following cesarean delivery under spinal anesthesia

BackgroundTransversus abdominis plane block is an effective method of post-cesarean analgesia. There are no data available about plasma bupivacaine levels after this block in adults. This study aimed to assess bupivacaine pharmacokinetic parameters after ultrasound-guided transversus abdominis plane blocks following cesarean delivery under spinal anesthesia.MethodsA prospective observational study in parturients undergoing elective cesarean delivery under hyperbaric bupivacaine spinal anesthesia was conducted. After surgery, patients received bilateral transversus abdominis plane block (50 mg bupivacaine each side). Venous blood samples were collected immediately before performing the block and at 10, 20, 30, 45, 60, 90, 120, 180, 240, 720 and 1440 minutes. High performance liquid chromatography was used to measure total plasma bupivacaine concentrations. Mean bupivacaine area under the curve (AUC) was calculated from 0 to 24 hours.ResultsData were collected from 17 parturients. Mean age and body mass index were 31 ± 6 y and 30 ± 4 kg/m² respectively. Mean plasma bupivacaine concentration before the block was 171 ng/mL. Mean peak concentration was 802.36 ng/mL (range 231.8 to 3504.5 ng/mL). Mean time to peak concentration was 30 min and mean area-under-the-curve (0–24 h) was 4505.4 h.ng/mL. Mean elimination half-life was 8.75 h. Three subjects had concentrations above the quoted toxic threshold and mild symptoms suggestive of neurotoxicity were reported by two subjects, but no treatment was required.ConclusionSingle-dose bilateral transversus abdominis plane block using 100 mg of bupivacaine, after spinal anesthesia for cesarean delivery, can result in toxic plasma bupivacaine concentrations.