Current consequences of prenatal diagnosis of congenital diaphragmatic hernia

Background

Today, the diagnosis of congenital diaphragmatic hernia (CDH) can readily be made in the prenatal period during screening ultrasound examination. Patients ought to be referred to rule out associated anomalies, and in isolated cases, prognosis is poor when the liver is intrathoracic and the lung-to-head ratio (LHR) is less than 1. In these patients, prenatal intervention aiming to reverse pulmonary hypoplasia can be considered.

Methods

We present our current algorithm for counselling patients presenting with CDH. Patients with a poor prognosis are offered percutaneous fetal endoluminal tracheal occlusion (FETO) with a balloon, inserted at 26 to 28 weeks. We report on the evolution of technique and results in a consecutive homogeneous case series and compare outcome in cases with similar severity managed in the postnatal period.

Results

Within a period of 28 months, FETO was performed between 26 and 28 weeks in 24 fetuses with severe left-sided CDH. Under general (n = 5), epidural (n = 17) or local (n = 2) anesthesia, the balloon was successfully positioned at first surgery (23/24) with a mean operation time of 20 minutes (range, 3-60 minutes). There were no serious maternal complications or direct fetal adverse effects. In the first 2 weeks after FETO, LHR increased from 0.7 to 1.7. Premature prelabour rupture of the membrane (PPROM) occurred in 16.7% and 33.3% at 28 and 32 weeks or earlier, respectively. Gestational age at delivery was 33.5 weeks. Patency of airways was restored either in the prenatal (n = 12) or perinatal period (n = 12). Early (7 days) and late (28 days) survival, and survival at discharge were 75% (18/24), 58.3% (14/24) and 50% (12/24), respectively. Half of nonsurvivors (n = 6) died of pulmonary hypoplasia and hypertension, in combination with PPROM and preterm delivery (n = 4) and balloon dislodgement (n = 2), which coincided with a short tracheal occlusion (TO) period (12 days). In the other 6, TO period was comparable to that in the 12 survivors (47 vs 42 days, respectively). In that group of 6 babies, only 2 died of pulmonary problems. Late neonatal survival (28 days) was higher with prenatal vs perinatal balloon retrieval 83.3% vs 33.3% (P = .013). In a multicentre study validating the criteria, survival till discharge in 37 comparable cases was 9% (3/32) and 13% (5/37) of parents opted for termination.

Conclusion

Fetuses with isolated left-sided CDH, liver herniation, and LHR of less than 1 have a poor prognosis. Percutaneous FETO is minimally invasive and may improve the outcome in these highly selected cases. Airways can be restored before birth, allowing vaginal delivery and return to the referring tertiary unit and may improve survival rate. The procedure carries a risk for PPROM, although that may decrease with experience.     

Congenital diaphragmatic hernia: prognostic indices in the fetal endoluminal tracheal occlusion era

Introduction

Management of congenital diaphragmatic hernia (CDH) in the UK now includes the possibility of fetal endoluminal tracheal occlusion (FETO) for poor prognosis fetuses. The objective of this study was to investigate the value of variables previously thought prognostic in the FETO era.

Methods

A retrospective single-centre study was performed of all infants with CDH born between January 1994 and December 2007. Fetal endoluminal tracheal occlusion was available and had been used with parental consent for fetuses with lung-to-head ratio (LHR) of 1.0 or less and a liver-up position from 2002. Univariate analysis was used to predict survival (to leave hospital) using both prenatal (eg, polyhydramnios) and perinatal variables [eg, best oxygenation index on day 1, or BOI (d1)] and their dependence tested in a logistic regression model. Data were quoted as medians (range). P < .05 was regarded as significant.

Results

Eighty-six infants with CDH (1994-2002, n = 35 and 2002-2007, n = 51 “FETO era”) were studied. Successful FETO intervention was performed in 31 infants.Univariate analysis showed liver position, birth weight, LHR, and BOI (d1) were significant prognostic predictors (all P < .05); however, only BOI (d1) retained significance using logistic regression analysis (odds ratio, 21; 95% confidence interval, 6-74; P < .001). Best oxygenation index on day 1 was then used as a surrogate marker for outcome to test the relationship with LHR (available since 2002) and showed a significant inverse correlation (r_s = −0.5; P < .001). There was no difference in median BOI (d1) between the FETO group and all those treated expectantly (40 [34-1046] vs 59 (23-581); P = .3].

Conclusion

Best oxygenation index on day 1 is the best early postnatal predictor of survival. The more recently evaluated prenatal index, LHR, has an observable relationship with BOI (d1) when it is used as a surrogate marker of outcome.     

Morbidity in children after fetoscopic endoluminal tracheal occlusion for severe congenital diaphragmatic hernia: Results from a multidisciplinary clinic

BackgroundAlthough fetoscopic endoluminal tracheal occlusion (FETO) was recently shown to improve survival in a multicenter, randomized trial of severe congenital diaphragmatic hernia (CDH), morbidity outcomes remain essentially unknown. The purpose of this study was to assess long-term outcomes in children with severe CDH who underwent FETO.MethodsWe conducted a prospective study of severe CDH patients undergoing FETO at an experienced North American center from 2015-2021 (NCT02710968). This group was compared to a cohort of non-FETO CDH patients with severe disease as defined by liver herniation, large defect size, and/or ECMO use. Clinical data were collected through a multidisciplinary CDH clinic. Statistics were performed with t-tests and Chi-squared analyses (p≤0.05).ResultsThere were 18 FETO and 17 non-FETO patients. ECMO utilization was 56% in the FETO cohort. Despite significantly lower median observed/expected lung-to-head ratio (O/E LHR) in the FETO group, [FETO: 23% (IQR:18-25) vs. non-FETO: 36% (IQR: 28-41), p<0.001], there were comparable survival rates at discharge (FETO: 78% vs. non-FETO: 59%, p = 0.23) and at 5-years (FETO: 67% vs. non-FETO: 59%, p = 0.53) between the two cohorts. At a median follow up of 5.8 years, metrics of pulmonary hypertension, pulmonary morbidity, and gastroesophageal reflux disease improved among patients after FETO. However, most FETO patients remained on bronchodilators/inhaled corticosteroids (58%) and were feeding tube dependent (67%).ConclusionsThese North American data show that prenatal tracheal occlusion, in conjunction with a long-term multidisciplinary CDH clinic, is associated with acceptable long-term survival and morbidity in children after FETO.Level of EvidenceLevel III     

Remifentanil for fetal immobilization and maternal sedation during fetoscopic surgery: a randomized, double-blind comparison with diazepam

Obstetric endoscopy procedures are routinely performed at our institution to treat selected complications of monochorionic twin gestation. We perform these procedures under combined spinal epidural anesthesia plus maternal sedation. In the absence of general anesthesia, fetal immobilization is not achieved. We hypothesized that remifentanil would induce adequate maternal sedation and provide fetal immobilization, which is equal or superior to that induced by diazepam. Fifty-four second trimester pregnant women were included in this randomized, double-blind trial. After combined spinal epidural anesthesia, maternal sedation was initiated using either incremental doses of diazepam or a continuous infusion of remifentanil. Maternal sedation, hemodynamics, side effects, and fetal hemodynamics and immobilization were evaluated before, during, and for 60 min after surgery. Remifentanil produced adequate maternal sedation with mild but clinically irrelevant respiratory depression (respiratory rate 13 +/- 4 breaths/min and Pco(2) 38.6 +/- 4 mm Hg at 40 min of surgery), whereas diazepam resulted in a more pronounced maternal sedation but no respiratory depression (respiratory rate 18 +/- 3 breaths/min and Pco(2) 32.7 +/- 3 mm Hg at 40 min of surgery). Compared with diazepam, fetal immobilization with remifentanil occurred faster and was more pronounced, resulting in improved surgical conditions; the number of gross body and limb movements was 12 +/- 4 (diazepam) versus 2 +/- 1 (remifentanil) at 40 min of surgery. Because of this, the mean (range) duration of surgery was significantly shorter in the remifentanil-treated patients, 60 (54-71) min versus 80 (60-90) min in the diazepam group. We conclude that remifentanil produces improved fetal immobilization with good maternal sedation and only minimal effects on maternal respiration.     

Comparison of general and epidural anesthesia in elective cesarean section for placenta previa totalis: maternal hemodynamics, blood loss and neonatal outcome

There are few consistent guidelines in choosing anesthesia for cesarean section for a parturient with placenta previa. This prospective randomized trial was organized to compare the maternal hemodynamics, blood loss and neonatal outcome of general versus epidural anesthesia for cesarean section with the diagnosis of grade 4 placenta previa. After giving informed consent, 12 patients received general anesthesia and 13 received epidural. Intraoperative blood pressures demonstrated a more stable course in the epidural group than in the general group. Blood loss did not differ significantly between the groups (1622 +/- 775 mL vs. 1418 +/- 996 mL). General anesthesia resulted in lower immediate postoperative hematocrit level (28.1 +/- 3.5% vs. 32.5 +/- 5.0%, P < 0.05). The patients in the general group received a significantly larger transfusion than the epidural group (1.08 +/- 1.6 vs. 0.38 +/- 0.9 units, P < 0.05). The Apgar scores at 1 and 5 min were similar in the two groups (8 [4-9] vs. 8 [7-9] and 10 [6-10] vs. 9 [9-10], respectively). We concluded that epidural anesthesia is superior to general anesthesia in elective cesarean section for grade 4 placenta previa with regard to maternal hemodynamics and blood loss. There was no difference in neonatal outcome.     

Postnatal care setting and survival after fetoscopic tracheal occlusion for severe congenital diaphragmatic hernia: A systematic review and meta-analysis

BackgroundFetoscopic endoluminal tracheal occlusion (FETO) was recently shown to improve postnatal survival in a multicenter, randomized controlled trial of infants with severe congenital diaphragmatic hernia (CDH). However, the external validity of this study remains unclear given a lack of standardization in postnatal management approaches. The purpose of this study was to evaluate the impact of an integrated prenatal and postnatal care setting on survival outcomes in severe CDH after FETO.Study designA systematic review, meta-analysis, and individual participant analysis of FETO outcomes in severe CDH were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The primary outcome was survival to discharge. Subgroup analyses of patients managed in integrated versus nonintegrated settings were performed to identify predictors of outcome.ResultsThe review generated five studies (n = 192) for the meta-analysis of FETO versus expectant prenatal management. These data revealed a significant survival benefit after FETO that was restricted to an integrated setting (OR 2.97, 95% Confidence Interval 1.69–4.26). There were nine studies (n = 150) for the individual participant analysis, which showed that FETO managed in an integrated setting had significantly increased survival rates when compared to FETO treated in a nonintegrated setting (70.7% vs. 45.7%, p = 0.003). Multi-level logistic regression identified increased availability of extracorporeal membrane oxygenation (ECMO) as the strongest determinant of postnatal survival (OR=18.8, p = 0.049).ConclusionThis systematic review shows that institutional integration of prenatal and postnatal care is associated with the highest overall survival in children with severe CDH. These data highlight the importance of a standardized, multidisciplinary approach, including access to ECMO, as a critical postnatal component in optimizing FETO outcomes in CDH.     

Epidural anesthesia worsens uterine blood flow and fetal oxygenation during hemorrhage in gravid ewes.

Recent studies suggest that epidural anesthesia initiated before hemorrhage may improve survival and acid-base status in laboratory animals. However, studies of hemorrhagic shock in nonpregnant animals may not be applicable to less severe hemorrhage in pregnant animals. The purpose of this study was to determine whether epidural anesthesia alters maternal and fetal hemodynamic and acid-base responses to hemorrhage in gravid ewes. Twenty-four experiments were performed in twelve chronically instrumented animals between 0.8 and 0.9 of timed gestation. The experimental sequence included: 1) T = 0 min: normal saline 500 ml intravenously; 2) T = 15 min: epidural administration of 0.5% bupivacaine (epidural group) or normal saline (control group); 3) T = 30 min: epidural administration of additional 0.5% bupivacaine (epidural group only) if the sensory level of anesthesia was below T10; 4) T = 45 min: maternal hemorrhage 20 ml/kg over 55 min; and 5) T = 110 min: transfusion of collected maternal blood over 55 min. At 45 min (i.e., 30 min after the epidural injection of bupivacaine), epidural bupivacaine resulted in a median sensory level of T9 in the epidural group. At that time, maternal mean arterial pressure was less (P less than 0.05) in the epidural group than in the control group (14 +/- 2% below baseline versus 4 +/- 1% above baseline, respectively). Maternal mean arterial pressure, heart rate, cardiac output, and uterine blood flow, and fetal PO2 and pH all were significantly less during hemorrhage (P less than 0.05) in the epidural group than in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)     

腰麻-硬膜外联合麻醉对剖宫产母婴肾素-血管紧张素-醛固酮系统的影响

目的 研究腰麻－硬膜外联合麻醉（CSEA）对剖宫产母婴肾素－血管紧张素－醋固酮系统（RAAS）的影响。方法 将60例ASA Ⅰ级行择期剖宫产的健康产妇随机分为硬膜外麻醉组（EA组，n＝30）和CSEA组（n＝30)。分别于注射局麻药前(T0)、切皮后即刻（T1）、胎儿晚出后即刻（T2）、术毕即刻（T3）和术后24h（T4）取母体静脉血和胎儿娩出后胎儿脐动、静脉血测定血清素活性（PRA）、血管紧张素Ⅱ（AT-Ⅱ）和醛固酮（ALD）浓度；评定麻醉效果，记录痛觉阻滞平面达T7水平的时间，注射局麻药至胎儿娩出时间（I－DI）及新生儿娩出1min、5min的Apgar评分。结果 两组术中SP、DP、HR、SpO2的变化及新生儿娩出1min、5min的Apgar评分。结果 两组术中SP、DP、HR、SpO2的变化及新生儿娩出1min、5min的Apgar评分差异无显著性（P＞0.05）。同EA组相比，CSEA组麻醉起效时间明显缩短（P＜0.01）。两组母体于T1、T2、T4的PRA、AT－Ⅱ、ALD值均比T0、T3值明显降低（P＜0.01），胎儿脐动、静脉血中三者值差异不明显，但明显低于母体T0、T3值（P＜0.01）。结论 CSEA用于剖宫产手术时，只要运用得当，不会对母婴AAS产生不良影响。     

Fetal anesthesia in cesarean section for patients with congenital diaphragmatic hernia

We experienced two cases of anesthesia for cesarean section in patients with prenatally diagnosed congenital diaphragmatic hernia (CDH). Fentanyl/midazolam anesthesia was selected for fetal sedation at birth. The blood samples were obtained from the maternal vein, umbilical vein and umbilical artery for measuring blood drug concentrations during anesthesia. Midazolam concentrations in umbilical vein were 137 and 256 ng.ml-1. Spontaneous breathing and movement of the newborns were restrained in both cases and these sedations facilitated preoperative general management for newborns with CDH.     

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.     

Epidural ropivacaine anesthesia decreases the bispectral index during the awake phase and sevoflurane general anesthesia

The sedative effects of epidural anesthesia without volatile and IV anesthetics and quantification of the degree of epidural anesthesia-induced sedation have not been investigated. In the current study we evaluated the effects of epidural anesthesia on the bispectral index (BIS) during the awake phase and during general anesthesia. After placing the epidural catheter, the patients were randomly allocated to 2 groups receiving either 5 mL of epidural saline (group S) or the same volume of 0.75% ropivacaine (group R). The BIS measurements during the awake phase were performed at 7, 12, 13, 14, 22, and 23 min after the epidural injection. General anesthesia was then induced with propofol and vecuronium and maintained with 0.75% sevoflurane. From approximately 10 min after tracheal intubation, the BIS measurements were made at 1-min intervals for 10 min. The BIS during the awake phase was significantly lower in group R than in group S (P < 0.05). The BIS during general anesthesia was significantly lower in group R than in group S (P < 0.0001). Epidural anesthesia decreased the BIS during the awake phase and during general anesthesia. The decrease of the BIS associated with epidural anesthesia was more prominent during general anesthesia than during the awake phase.     

腰麻联合双管硬膜外分娩镇痛的临床效果

目的评估腰麻联合双管硬膜外分娩镇痛的效果及对母婴的影响。方法 2015年4月至2016年1月于本院要求分娩镇痛的初产妇129例,随机分为两组。D组(n=68)腰麻后双管硬膜外阻滞分娩镇痛,S组(n=61)腰麻后单管硬膜外阻滞分娩镇痛。记录镇痛前(T0)及镇痛后10min(T1)、30 min(T2)、120 min(T3)、宫口开至7~8 cm(T4)、宫口开全(T5)、第二产程用力分娩时(T6)的VAS疼痛评分,各产程时间及缩宫素使用情况,镇痛泵按压及镇痛药物使用情况,分娩方式,产时出血量,新生儿情况和镇痛不良反应。结果 T0~T4时两组VAS评分差异无统计学意义,T5、T6时D组VAS评分明显低于S组(P0.05)。镇痛泵有效按压次数及镇痛药物使用量两组差异无统计学意义,但镇痛泵总按压次数D组明显少于S组(P0.05)。各产程时间、缩宫素使用率、分娩方式、产时出血量、新生儿情况和镇痛不良反应两组差异均无统计学意义。结论腰麻联合双管硬膜外分娩镇痛效果确切,不良反应少,产妇满意度高,对母婴是安全的。     

Comparison of maternal satisfaction between epidural and spinal anesthesia for elective Cesarean section

PURPOSE: Epidural anesthesia was a commonly used technique for elective Cesarean section. Recently, because of the availability of non-cutting spinal needles, many institutions have changed from epidural to spinal anesthesia. The purpose of this study was to compare maternal satisfaction between epidural and spinal anesthesia for elective Cesarean section with a new satisfaction tool. METHODS: We studied healthy parturients in a randomized, double-blinded pilot study in which patients were assigned to receive either epidural (n = 13) or spinal (n = 14) anesthesia for elective Cesarean section. Two and 24 hr postoperatively, patients completed a validated 22-point maternal satisfaction questionnaire and a 10-cm visual analog score (VAS) for satisfaction. Maternal satisfaction scores were compared between groups. RESULTS: There was no difference in demographics, complications or technical failures between groups. Mean satisfaction scores on the questionnaire (0-154) at two and 24 hr were 130.23 +/- 11.36 and 129.54 +/- 16.70 for the epidural group and 116.92 +/- 18.47 and 115.92 +/- 15.71 for the spinal group (P = 0.04 and P = 0.03 respectively). No difference in VAS scores was noted. The presence of minor side effects including pruritus contributed to the lower satisfaction in the spinal group at 24 hr. CONCLUSION: This pilot study demonstrated higher maternal satisfaction with epidural than with spinal anesthesia for elective Cesarean section. This may be related to the increased side effects caused by neuraxial morphine. The satisfaction questionnaire was able to elucidate differences not detected with a global VAS for satisfaction. Further study with a larger patient population is required to confirm these data.     

Central neuraxial blockade promotes external cephalic version success after a failed attempt

External cephalic version (ECV) has been successfully used to decrease the fetal and maternal morbidity and costs of cesarean delivery. As there are limited data regarding the use of central neuraxial blockade in the setting of previously failed ECV attempts, we sought to evaluate the efficacy and safety of spinal and epidural anesthesia in this setting. A retrospective review of all ECV attempts performed by a single experienced obstetrician between 1995 and 1999 was conducted. Standardized tocolytic and anesthetic regimens were used. A total of 77 patients underwent ECV attempts; of these, 37 (48%) were unsuccessful, 15 of which consented to further attempts with anesthesia. Neuraxial anesthesia was associated with frequent ECV success in both multiparous 4/4 (100%) and nulliparous 9/11 (82%) parturients. Overall 5/6 (83%) and 8/9 (89%) (P = NS) ECV attempts were successful with spinal and epidural anesthesia, respectively, with 2/5 (40%) and 6/8 (75%) (P = NS) resulting in vaginal deliveries. One successful ECV in the epidural group had an urgent cesarean delivery for persistent fetal bradycardia with good neonatal and maternal outcomes. We conclude central neuraxial anesthesia promotes successful ECV after previously failed ECV attempts. IMPLICATIONS: Our retrospective analysis of central neuraxial techniques, both epidural and spinal anesthesia, noted a significant success rate in the setting of previously failed external cephalic version attempts.     

Prenatal surgery for congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) has a mortality rate of up to 77% despite optimal pre- and postnatal care. Fetuses with liver herniation, a low lung-to-head ratio, and an early diagnosis before 24 weeks have a particularly poor prognosis. In utero open repair of these fetuses does not improve patient survival. The PLUG (Plug the Lung Until it Grows) technique was reported to be able to reverse pulmonary hypoplasia in CDH. A foam plug or a titanium clip is used and the trachea can be unplugged using Ex Utero Intrapartum Tracheoplasty (EXIT) at birth. Since hysterotomy causes premature labour, a video-fetoscopic intrauterine technique of tracheal occlusion called Fetendo-PLUG was developed. Compared to those who receive standard postnatal care or fetal tracheal occlusion via open hysterotomy, patients who undergo Fetendo-PLUG are reported to have a higher survival rate of 75% and fewer fetal and maternal complications. A recent refinement is to use a detachable balloon for intratracheal occlusion through a single 5 mm port under real-time ultrasound guidance. Without the need for neck dissection, injury to the recurrent laryngeal nerves and trachea and vocal cord paresis can be minimized. The result of this form of treatment for CDH is promising, but further refinement of fetal instrumentation and development of effective tocolytic drugs are still required.     

Hemodynamic stability during labor and delivery with continuous epidural infusion

CONTEXT: Epidural anesthesia for labor pain is frequently complicated by maternal hypotension. OBJECTIVE: To test whether continuous epidural infusion (CEI) of local anesthetic, without bolus administration, lowers the incidence of hypotension in parturient patients. METHODS: In a single-blind clinical study, subjects were randomly assigned to CEI-only (10 mL/h of 0.2% ropivacaine hydrochloride without bolus) or control (10 mL of 0.2% ropivacaine hydrochloride per hour with 10-mL bolus) epidural dosing groups. The incidence of hypotension (20% decrease in systolic blood pressure or mean arterial pressure (MAP), systolic blood pressure lower than 100 mm Hg, or MAP lower than 65 mm Hg) was recorded for 2 hours after dosing. Statistical analysis included a 2x2 chi(2) analysis, the Fisher exact test, and paired two-tailed t tests. RESULTS: Fifty subjects were studied, with 25 randomly assigned to each study group (CEI-only vs control). Baseline blood pressure was not different between groups (CEI-only, 127 [11]/77 [8.7] mm Hg; control, 131 [14]/78 [2]). The incidence of hypotension was lower in the CEI-only group than in the control group (5 [20%] vs 15 [60%]; P=.009), with intervention required in 1 (20%) of 5 CEI-only subjects and 7 (47%) of 15 control subjects. Sensory block reached the T10 dermatome in 54.4 (18) minutes in the CEI-only group and 38 (24) minutes in the control group (P=.04). Pain scores and maternal and fetal pulse rates were not different between groups. Analgesic supplementation (250 microg of epidural fentanyl) was used more frequently in the CEI-only group (72% vs 32%; P=.01), without adverse effects. CONCLUSIONS: Continuous epidural infusion of 0.2% ropivacaine hydrochloride without bolus administration reduces the incidence of hypotension by 67% and is safer than traditional bolus dosing for routine labor. This method requires further study in high-risk patients, including those with preeclampsia and cardiovascular disease.     

Central effects of epidural and intravenous clonidine in patients anesthetized with enflurane/nitrous oxide. An electroencephalographic analysis.

Epidural clonidine produces regional anesthesia as well as sedation and a decrease in anesthetic requirements. To assess these effects, the electroencephalogram (EEG) was recorded after epidural or intravenous (iv) injection of clonidine during enflurane/N2O anesthesia. Eighteen ASA physical status 1 women undergoing vaginal hysterectomy were allocated randomly to receive epidural clonidine (8 micrograms.kg-1 in 4 ml over 2 min) and iv saline (10 ml over 14 min); or epidural saline (4 ml over 2 min) and iv clonidine (8 micrograms.kg-1 in 10 ml over 14 min); or epidural saline (4 ml over 2 min) and iv saline (10 ml over 14 min). The level of anesthesia was kept constant beginning 10 min before and until 44 min after epidural injection. EEG power spectral analysis was performed throughout the study period using a 2-min average of 8-9-s epochs. Clonidine significantly reduced EEG total power only after epidural administration (P less than 0.05). Relative power increased in the delta band in both the epidural and iv clonidine groups (P less than 0.001). The depression of the total EEG power after epidural injection could be explained neither by systemic absorption alone nor by hemodynamic variations. It may represent the contribution of the direct spinal action of this alpha 2-adrenergic agonist to general anesthesia.     

Fetal lung-head ratio is not related to outcome for antenatal diagnosed congenital diaphragmatic hernia

We asked if fetal lung-to-head ratio (LHR) of 1.0 or lower or liver herniation had a statistical effect on survival or need for extracorporeal membrane oxygenation (ECMO), compared with LHR above 1.0 in patients with congenital diaphragmatic hernia (CDH).

Methods

Antenatal records of all patients diagnosed with CDH from January of 2002 to June of 2005 were examined. Inclusion criteria were isolated left-sided CDH and absence of significant cardiac or other anomalies/syndromes, treated solely at this institution. Lung-to-head ratio values were compared based on the value currently proposed for fetal intervention: LHR of 1.0 or lower vs LHR above 1.0. Outcome was assessed as survival (discharge to home) or need for ECMO.

Results

Twenty-eight patients met inclusion criteria. Overall survival was 86% (24/28). Postnatal survival in fetuses with LHR of 1.0 or lower (8/11) was not statistically different from LHR above 1.0 (16/17) (73% vs 94%, P = .114). The need for ECMO in the group with LHR of 1.0 or lower (3/11) was not significantly different from those with LHR above 1.0 (1/17) (27% vs 6%, P = .114). Herniation of the fetal liver into the chest did not affect survival or need for ECMO (P = .228).

Conclusion

Neither LHR of 1.0 or lower nor liver herniation identified a risk factor significant enough to warrant fetal intervention. Multicenter studies may be more appropriate to investigate this clinical problem.     

Effect of ranitidine on bupivacaine disposition

This study was undertaken to determine the effect, if any, of ranitidine on bupivacaine disposition in 28 women undergoing cesarean section. Before epidural anesthesia, ranitidine (50 mg IM) or sodium citrate (30 mL orally) was administered to groups of 14 parturients each. Ranitidine was administered 2 h before epidural anesthesia and sodium citrate was administered 10 min before the epidural. Maternal plasma samples were collected after epidural anesthesia with bupivacaine. A total of 15 maternal plasma samples were taken from the time of administration of epidural anesthesia up to 180 min. Postpartum plasma and urine samples were also collected from both mothers and neonates. Plasma samples were collected up to 48 h postpartum at intervals of 12, 24, and 48 h. Urine samples were collected at six 6-h intervals up to 36 h postpartum. A two-way analysis of variance with repeated measures demonstrated that there was no significant difference in bupivacaine levels between the maternal plasma curves of the ranitidine and the control groups. At the time of delivery, plasma levels of bupivacaine and its N-dealkylated metabolite PPX (2,6-pipecolylxylidine) were no different in the mothers or neonates of either group. There was no significant difference in plasma protein binding of bupivacaine in the presence of ranitidine. The excretion rates of bupivacaine and PPX were not measurably influenced by ranitidine. The amount of bupivacaine excreted, the amount of metabolite excreted, and the percentage of drug excreted as metabolite in maternal urine were not significantly different. These data indicate that there is no measurable effect of ranitidine on the disposition of bupivacaine in parturients.     

Prenatal diagnosis and natural history of the fetus with a congenital diaphragmatic hernia: initial clinical experience

To study the accuracy of prenatal diagnosis and define the natural history of fetal congenital diaphragmatic hernia (CDH), we reviewed experience with CDH at The University of California, San Francisco (UCSF) over the last three years. All nine babies born in our institution (inborns) and six of 11 babies referred from other hospitals after birth (outborns) died, an overall mortality of 75%. All had pulmonary hypoplasia. Forty percent had associated malformations or chromosomal abnormalities, a higher incidence than generally reported. Prenatal sonograms were available in all nine inborn cases. CDH was correctly diagnosed prospectively in only five, but could be recognized retrospectively in all nine cases using the sonographic criteria developed from the study. Polyhydramnios was present in all nine cases; in seven cases sonography was performed because the woman was large-for-dates clinically. There were no false positive interpretations, and when necessary the diagnosis was confirmed by amniography. All nine cases of CDH detected in utero died. Seven deteriorated so rapidly that surgical repair could not even be attempted. Two who had optimal care (maternal transport, immediate resuscitation and operation) died after repair despite maximal intensive care including vasodilator therapy. Despite the theoretical advantages of maternal transport to pediatric surgical specialty centers, a majority of fetuses with a prenatal diagnosis of CDH will die because their lungs are inadequate to support extra-uterine life even at term.