Effects on the fetus and newborn of maternal analgesia and anesthesia: a review

An Evidence-Based Discussion of Fetal Pain and Stress

BACKGROUND

The concept of fetal pain results from procedures conducted without anesthesia in preterm newborns and fetuses, which indicate that it is possible to examine fetal pain based on stress hormone, metabolic, and behavioral changes. Anatomical and physiological data suggest that fetuses become capable of processing nociceptive stimuli around midgestation, although the associated changes in fetal brain development remain unclear. What constitutes fetal pain remains controversial in the light of the definition of pain adopted by the International Association for the Study of Pain (IASP), which posits pain as an "unpleasant sensory and emotional experience."

SUMMARY

Here, we examine the notion that human fetuses cannot "experience" pain and potential implications of this claim. We highlight the key scientific evidence related to fetal pain, including clinical studies on pain in fetuses and preterm newborns. We argue that consistent patterns of stress hormones, metabolic changes, body movements, hemodynamic changes, and pain-related facial expressions in fetuses exposed to invasive procedures overcome the need for subjective proof of pain as articulated in the IASP definition. No study to date has conclusively proven the absence of fetal pain beyond the age of viability.

KEY MESSAGES

Based on the current evidence, we propose that all fetuses receive anesthesia regardless of the invasive procedures being performed to guarantee the least possible pain and physiological, behavioral, or hormonal responses without exposing the mother or her baby to unnecessary complications.

Ethical Principles Do Not Support Mandatory Preanesthesia Pregnancy Screening Tests: A Narrative Review

Respect for patient autonomy is a pillar of medical ethics, manifested predominantly through informed consent. Mandatory (routine) nonconsented preoperative urine pregnancy testing does not adequately respect patient autonomy, is potentially coercive, and has the potential to cause harm medically, psychologically, socially, and financially. Inaccuracies in pregnancy testing can result in false-positive and false-negative results, especially in early pregnancy. There is substantial scientific evidence that anesthesia is not harmful to the fetus, raising the question of whether pregnancy testing provides substantial benefit to the patient. Not performing a preanesthesia pregnancy test has not been associated with significant medicolegal consequences. We review the ethical implications of mandatory preanesthesia pregnancy testing in light of these facts.

Supreme laryngeal mask airway for cesarean section under general anesthesia: a 10-year retrospective cohort study

Background

Previous research showed the use of supraglottic airways in obstetric anesthesia. The relevant evidence of laryngeal mask airway (LMA) on maternal and neonatal outcomes is still limited. We aimed to assess the maternal and neonatal outcomes when the LMA Supreme was used for cesarean section under general anesthesia.

Methods

We included all patients who underwent general anesthesia for cesarean section between January 2010 and December 2019. Propensity score matching was used to reduce potential bias from non-random selection of airway intervention. The primary outcome was adverse maternal and neonatal outcomes defined as maternal regurgitation, aspiration, hypoxemia, and low neonatal Apgar scores. Secondary outcomes included patient admission to the intensive care unit, neonate required tracheal intubation, external cardiac massage, and admission to the neonatal intensive care unit.

Results

A total of 723 patients were included in the analysis; of whom, 221 received Supreme laryngeal mask airway (LMA group) and 502 were intubated with an endotracheal tube (ETT group). After propensity score matching, 189 patients remained in each group. No episode of regurgitation and aspiration occurred in both groups. There was no difference in the rates of Apgar score below 7 at 1 min (14.3% LMA group vs. 15.3% ETT group, OR 0.931, 95% CI 0.574 to 1.510, P = 0.772) and 5 min (3.7% vs. 4.2%, OR 0.875, 95% CI 0.324 to 2.365, P = 0.792). No difference was observed in the secondary outcomes between the two groups.

Conclusion

The LMA Supreme was not associated with higher adverse maternal and neonatal outcomes when compared to an endotracheal tube for cesarean section under general anesthesia. It might be considered an alternative to tracheal intubation in obstetric practice.

Can Hypotension Episodes that were not Identified in the Non-Invasive Blood Pressure be Detected during Cesarean Section? A Randomized Controlled Trial

Background:

Aims:

Study Design:

Methods:

Results:

Conclusion:

Non-reassuring fetal status and anesthetic impact on cesarean section-delivered very-low-birthweight infants

BACKGROUND

There is limited evidence concerning the impact on neonatal outcomes of different types of anesthesia used for cesarean delivery due to non-reassuring fetal status (NRFS). We aimed to assess the impact of NRFS and general anesthesia (GA) on neonatal outcomes in very-low-birthweight (VLBW) infants delivered by cesarean section.

METHODS

Data were collected relating to VLBW infants admitted to our institution. Infants were grouped into no-NRFS and NRFS groups and further subcategorized into GA and regional anesthesia (RA) subgroups. Neonatal outcomes were evaluated based on the presence of NRFS and the type of anesthesia.

RESULTS

A total of 356 infants were included. The GA subgroup in the no-NRFS group had higher requirements for respiratory support. However, GA was not associated with adverse neonatal outcomes based on the multivariable logistic regression analysis except for 5 min Apgar score <5. On the other hand, NRFS was associated with an increased risk of 5 min Apgar score <5 [adjusted odds ratio (aOR) 2.062, 95% confidence interval (CI) 1.064-3.997], use of high-frequency ventilation (aOR: 2.891, 95% CI: 1.477-5.658), and pulmonary hypertension (aOR: 2.890, 95% CI: 1.436-5.819).

CONCLUSIONS

In our cohort of VLBW infants, NRFS was a significant risk factor for a low 5 min Apgar score, increased respiratory support requirement, and pulmonary hypertension. Accurate assessment of fetal well-being, timely delivery, and presence of a resuscitation team fully aware of perinatal conditions and anesthetic impact is important.

Microdiscectomy Under Local Anesthesia and Spinal Block in a Pregnant Female

The surgical plan and the anesthetic approach are vital in determining the proper treatment of lumbar disc herniation in pregnancy. The diagnostic tools available, as well as the anesthetic agents and methods of delivery, vary in pregnant patients due to factors such as radiation exposure and hemodynamics in the patient and fetus. The gestational age also plays an important role in determining treatment options. When possible, surgery should be avoided during the first trimester, especially during the period of organogenesis, as general anesthesia can interfere with this process. However, when focal neurological deficits are present, urgent surgical decompression may be necessary. In such cases, the selection of anesthesia must be guided by maternal indications and the nature of the surgery. Maternal safety and avoidance of fetal hypoxia and subsequent preterm labor are crucial when pregnant patients receive anesthesia. As a result, local anesthesia is often preferred when possible due to the decreased risk of systemic toxicity. Decompression surgery in pregnant females with lumbar disc herniation, using a multidisciplinary approach among the surgeon, obstetrician, and anesthesiologist, is an effective and safe procedure for both the mother and the fetus. We present the case of a pregnant female at four weeks of gestation who presented with lower back pain radiating down her right leg. MRI of the lumbar spine showed large L4-5 disc herniation. She underwent a successful right L4-5 microdiscectomy under local anesthesia and spinal block using bupivacaine and was completely awake throughout the procedure. Postoperatively, she experienced immediate improvement of symptoms.

Seguridad de la anestesia neuroaxial en mujeres con embarazo gemelar y síndrome de transfusión feto-fetal, sometidas a fotocoagulación láser. Estudio de cohorte retrospectiva

Objetivo: describir las características clínicas y la frecuencia de complicaciones maternas, fetales y neonatales, según técnica de anestesia neuroaxial (AN) en mujeres con síndrome de transfusión feto-fetal (STFF) tratadas con fotocoagulación láser (FL). Materiales y métodos: estudio de cohorte retrospectiva descriptivo. Se incluyeron gestantes con STFF tratadas con FL y AN en la Fundación Valle del Lili, Cali (Colombia) entre 2013-2017. Se excluyeron pacientes con STFF estadio-V de Quintero. Se usó estadística descriptiva. El protocolo fue aprobado por el Comité de Ética de la institución. Resultados: 32 participantes cumplieron con los criterios de inclusión y de exclusión. La población estuvo constituida por mujeres jóvenes, multíparas. En el 87,5% de los casos se realizó intervención de urgencia. El 43,7% presentaba el estadio-III de Quintero y en el 56,2 % de las gestantes se utilizó anestesia epidural. Las variables hemodinámicas maternas exhibieron un comportamiento similar, acorde al momento de la cirugía y la técnica neuoraxial implementada. El 65,6 % de las gestantes presentó hipotensión sostenida y el 9,3 % desarrolló edema pulmonar. El 65,6 % de las pacientes experimentó parto pretérmino y el 18,7 % ruptura prematura de membranas. Se registraron 14 muertes fetales y cinco neonatales. No se registraron casos de mortalidad materna. Conclusiones: en pacientes con STFF que requieren FL, el uso de la anestesia epidural, espinal o combinada probablemente se asocia con un comportamiento similar al de las variables hemodinámicas maternas, durante los momentos de la cirugía. Los profesionales que brindan atención a estas gestantes deben estar alerta ante la frecuente aparición de complicaciones maternas, fetales y neonatales. Se requieren estudios prospectivos que evalúen la seguridad y la efectividad de las diferentes técnicas de anestesia neuroaxial en pacientes con STFF.

Effects of Pregnancy Anesthesia on Fetal Nervous System

The effects of general anesthesia on the developing brain remain a great concern in the medical field and even in the public, and most researches in this area focus on infancy and childhood. In recent years, with the continuous development of medical technology, the number of operations during pregnancy is increasing, however, studies on general anesthesia during pregnancy are relatively lacking. The mid-trimester of pregnancy is a critical period, and is regarded as a safe period for surgery, but it is a fragile period for the development of the central nervous system and is particularly sensitive to the impact of the environment. Our research group found that general anesthesia may have adverse effects on fetal neurodevelopment during the mid-trimester. Therefore, in this review, we summarize the characteristics of anesthesia during pregnancy, and the related research of the anesthesia’s impacts on the development of central nervous system were introduced.

Spine surgery in pregnant women: a multicenter case series and proposition of treatment algorithm

PURPOSE

Spinal diseases requiring urgent surgical treatment are rare during pregnancy. Evidence is sparse and data are only available in the form of case reports. Our aim is to provide a comprehensive guide for spinal surgery on pregnant patients and highlight diagnostic and therapeutic aspects.

METHODS

The study included a cohort of consecutive pregnant patients who underwent spinal surgery at five high-volume neurosurgical centers between 2010 and 2017. Perioperative and perinatal clinical data were derived from medical records.

RESULTS

Twenty-four pregnant patients were included. Three underwent a preoperative cesarean section. Twenty-one patients underwent surgery during pregnancy. Median maternal age was 33 years, and median gestational age was 13 completed weeks. Indications were: lumbar disk prolapse (n = 14; including cauda equina, severe motor deficits or acute pain), unstable spine injuries (n = 4); intramedullary tumor with paraparesis (n = 1), infection (n = 1) and Schwann cell nerve root tumor presenting with high-grade paresis (n = 1). Two patients suffered transient gestational diabetes and 1 patient presented with vaginal bleeding without any signs of fetal complications. No miscarriages, stillbirths, or severe obstetric complications occurred until delivery. All patients improved neurologically after the surgery.

CONCLUSION

Spinal surgical procedures during pregnancy seem to be safe. The indication for surgery has to be very strict and surgical procedures during pregnancy should be reserved for emergency cases. For pregnant patients, the surgical strategy should be individually tailored to the mother and the fetus.

Comparison of Intravenous Nalbuphine and Paracetamol on Maternal Hemodynamic Status, Neonatal APGAR Score, and Postoperative Pain given before Induction of General Anesthesia for Elective Cesarean Section

Background:

Stress response to endotracheal intubation and surgery is associated with exaggerated hemodynamic response and an increase in catecholamine levels which is deleterious to both the mother and fetus. We aimed to compare the effects of intravenous nalbuphine and paracetamol on maternal hemodynamic status, neonatal APGAR score, and postoperative pain using the visual analog scale for elective cesarean section under general anesthesia.

Study Design:

This was a prospective, randomized, double-blinded clinical study.

Materials and Methods:

Sixty full-term pregnant patients, belonging to the American Society of Anaesthesiologist physical status Classes I and II, scheduled for elective cesarean section under general anesthesia were enrolled for the study. The patients were randomly allocated into two groups of 30 patients each to receive paracetamol (15 mg.kg^{− 1}) in Group Pand nalbuphine (0.2 mg.kg⁻¹) in Group N before induction of general anesthesia. Maternal heart rate, blood pressure, and oxygen saturation were recorded before infusion of study drugs, after induction, after intubation, and during surgery across all periods. APGAR score of neonates was recorded by a pediatrician. Time to reach visual analogue score-1 was recorded.

Results:

Significant attenuation of maternal hemodynamic response was observed with nalbuphine compared to the paracetamol group (P < 0.05). The time to achieve visual analogue score-1 in the postoperative period was higher in the nalbuphine group. APGAR score at 1 min was significant between the groups and at 5 min, nonsignificant difference was observed (P > 0.05).

Conclusion:

Nalbuphine and paracetamol are effective in perioperative hemodynamic stability of mother and APGAR score of neonates. However, nalbuphine had better hemodynamic stability as compared to paracetamol with a comparable APGAR score at 5 min.

Safety of anesthetic exposure on the developing brain - Do we have the answer yet?

During the past two decades, a vast number of studies done on rodents and nonhuman primates have implicated general anesthetic exposure of developing brains in producing neurotoxicity leading to various structural and functional neurological abnormalities with cognitive and behavioral deficits later in life. However, it is still unclear whether these findings translate to children and whether single exposure to anesthesia in childhood can have long-term neuro-developmental risks. Considering the fact that a large number of healthy young children are undergoing elective surgery under general anesthesia globally, any such potential neurocognitive risk of pediatric anesthesia is a serious public health issue and is therefore important to understand. This review aims to assess the current preclinical and clinical evidence related to anesthetic neurotoxicity.

Safety of anesthetic exposure on the developing brain - Do we have the answer yet?

During the past two decades, a vast number of studies done on rodents and nonhuman primates have implicated general anesthetic exposure of developing brains in producing neurotoxicity leading to various structural and functional neurological abnormalities with cognitive and behavioral deficits later in life. However, it is still unclear whether these findings translate to children and whether single exposure to anesthesia in childhood can have long-term neuro-developmental risks. Considering the fact that a large number of healthy young children are undergoing elective surgery under general anesthesia globally, any such potential neurocognitive risk of pediatric anesthesia is a serious public health issue and is therefore important to understand. This review aims to assess the current preclinical and clinical evidence related to anesthetic neurotoxicity.

Epidural analgesia during labour and stress markers in the newborn

Labour and modes of delivery can influence the plasma levels of stress hormones and cytokines involved in pathophysiologic cascade, potentially damaging brain development of the newborn. This prospective observational, single-centre, case-control, non-profit study aimed to detect potential differences in foetal well-being such as stress neuroendocrine responses. Quantitative determinations of the stress markers interleukin (IL)-1β, IL-8, and β-endorphin were compared between the control group and the epidural analgesia group. We found higher IL1-β levels but lower IL-8 and β-endorphin levels in the epidural analgesia group than in the control group. No significant inter-group differences were observed for any parameters. Our findings demonstrate that epidural analgesia for pain relief during labour does not result in significant differences in blood stress response markers.IMPACT STATEMENTWhat is already known on this subject? We already know that plasma levels of stress hormones and cytokines are influenced by labour and delivery modes. This has a deep impact on the newborn in terms of brain damage, immune system deficits, and altered hypothalamic-pituitary axis responses. We also know that epidural analgesia is a widespread practice that offers pain relief to the woman in labour, but there are few studies on the potentially negative effects of epidural labour analgesia on the unborn child.What do the results of this study add? This study found no significative differences in blood stress response markers between the epidural analgesia group and the control group. Under this study circumstances we found out that epidural analgesia does not significantly influence the newborn's well-being during labour and delivery.What are the implications of these findings for clinical practice and/or further research? These findings must be confirmed by further studies to verify whether epidural analgesia is safe for the newborn's development.

Investigation of the Minimum Local Analgesic Concentration of Epidural Sufentanil Combined With Ropivacaine for Labor Analgesia

PURPOSE

Worldwide, there are only few studies focusing on labor analgesia on the MLAC (minimum local analgesic concentration) or EC50 (median effective concentration) of sufentanil and ropivacaine. Therefore, we determine the MLAC or EC50 of sufentanil and ropivacaine for epidural analgesia by using an up-down sequential allocation and survey its adverse effect in a prospective blinded randomized trial.

METHODS

Sixty nulliparous full-term parturients who required labor analgesia were recruited and randomly divided into the sufentanil and ropivacaine groups. The formulation was 25 μg sufentanil combined with 0.1% ropivacaine (added 0.9% normal saline to 75 ml). According to the response of a previous parturient, the dosage of sufentanil was increased or decreased by 5 μg in the sufetanil group; meanwhile, we also administrated an initial concentration of 0.1% ropivacaine combined with 22.5 μg sufentanil (added 0.9% normal saline to 75 ml) in the ropivacaine group. The concentration of ropivacaine was increased or decreased by 0.01% following the response of the previous parturient. The Brownlee up-down sequential allocation was used to estimate the MLAC of epidural ropivacaine and its 95% confidence intervals in labor analgesia.

FINDINGS

There were no significant changes for the two groups, including for age, height weight, active stage, second stage of labor, and gestational weeks (P = 0.769, 0.900, 0.603, 0.441, 0.577, and 0.695, respectively). The VAS scores of the parturient decreased to varying degrees (P < 0.0001) after labor analgesia compared with VAS before labor analgesia, and the most effective analgesia was reached in 60 min. The EC50 dose of epidural ropivacaine combined with 0.3 μg/mL sufentanil was 0.09687%, and the 95% CI was 0.08944%~0.1043%. Five parturients had PONV, and the incidence rate was 16.7%; one parturient had pruritus, so the incidence rate was 3.3%. The EC50 dose of epidural sulfetanil combined with 0.1% ropivacaine was 18.76 μg with a 95% confidence interval of 13.5-24.48 μg. There were no significant differences in the active stage, second stage of labor, and maternal and fetal hemodynamic data between the two groups. Notably, the Apgar scores for 1 min and 5 min were 10 scores for almost all of these patients. There were no significant differences between the two groups for maternal and fetal side effects, which had very low incidence rates.

IMPLICATIONS

The MLAC of epidural sufentanil or ropivacaine could provide satisfactory and safe analgesia for parturients while having a low incidence rate of side effects.

Women's experiences of pharmacological and non-pharmacological pain relief methods for labour and childbirth: a qualitative systematic review

BACKGROUND

Many women use pharmacological or non-pharmacological pain relief during childbirth. Evidence from Cochrane reviews shows that effective pain relief is not always associated with high maternal satisfaction scores. However, understanding women's views is important for good quality maternity care provision. We undertook a qualitative evidence synthesis of women's views and experiences of pharmacological (epidural, opioid analgesia) and non-pharmacological (relaxation, massage techniques) pain relief options, to understand what affects women's decisions and choices and to inform guidelines, policy, and practice.

METHODS

We searched seven electronic databases (MEDLINE, CINAHL, PsycINFO, AMED, EMBASE, Global Index Medicus, AJOL), tracked citations and checked references. We used thematic and meta-ethnographic techniques for analysis purposes, and GRADE-CERQual tool to assess confidence in review findings. We developed review findings for each method. We then re-analysed the review findings thematically to highlight similarities and differences in women's accounts of different pain relief methods.

RESULTS

From 11,782 hits, we screened full 58 papers. Twenty-four studies provided findings for the synthesis: epidural (n = 12), opioids (n = 3), relaxation (n = 8) and massage (n = 4) - all conducted in upper-middle and high-income countries (HMICs). Re-analysis of the review findings produced five key themes. 'Desires for pain relief' illuminates different reasons for using pharmacological or non-pharmacological pain relief. 'Impact on pain' describes varying levels of effectiveness of the methods used. 'Influence and experience of support' highlights women's positive or negative experiences of support from professionals and/or birth companions. 'Influence on focus and capabilities' illustrates that all pain relief methods can facilitate maternal control, but some found non-pharmacological techniques less effective than anticipated, and others reported complications associated with medication use. Finally, 'impact on wellbeing and health' reports that whilst some women were satisfied with their pain relief method, medication was associated with negative self-reprisals, whereas women taught relaxation techniques often continued to use these methods with beneficial outcomes.

CONCLUSION

Women report mixed experiences of different pain relief methods. Pharmacological methods can reduce pain but have negative side-effects. Non-pharmacological methods may not reduce labour pain but can facilitate bonding with professionals and birth supporters. Women need information on risks and benefits of all available pain relief methods.

European Society of Anaesthesiology Task Force on Nitrous Oxide: a narrative review of its role in clinical practice

Nitrous oxide (N₂O) is one of the oldest drugs still in use in medicine. Despite its superior pharmacokinetic properties, controversy remains over its continued use in clinical practice, reflecting in part significant improvements in the pharmacology of other anaesthetic agents and developing awareness of its shortcomings. This narrative review describes current knowledge regarding the clinical use of N₂O based on a systematic and critical analysis of the available scientific literature. The pharmacological properties of N₂O are reviewed in detail along with current evidence for the indications and contraindications of this drug in specific settings, both in perioperative care and in procedural sedation. Novel potential applications for N₂O for the prevention or treatment of chronic pain and depression are also discussed. In view of the available evidence, we recommend that the supply of N₂O in hospitals be maintained while encouraging its economic delivery using modern low flow delivery systems. Future research into its potential novel applications in prevention or treatment of chronic conditions should be pursued to better identify its role place in the developing era of precision medicine.

General Anesthesia with the Use of SUPREME Laryngeal Mask Airway for Emergency Cesarean delivery: A Retrospective Analysis of 1039 Parturients

In comparison to elective cesarean delivery, emergency cesarean delivery under endotracheal intubation is associated with higher risk of life-threatening airway problems. In this retrospective study, we evaluate the efficacy and feasibility of using SUPREME laryngeal mask airway (SLMA) in emergency cesarean delivery under general anesthesia (GA). The study included a total of 1039 paturients undergoing emergency cesarean delivery under GA with SLMA from January 2015 to December 2015 at Quanzhou Children’s and Women’s Hospital. Outcome measures included incidence of the adverse events related to using SLMA, maternal mortality, and neonatal outcomes. Briefly, no aspiration or regurgitation was noticed; the first attempt was successful in all but 2 subjects, both because of incorrect location, one was detected by decreasing oxygenation and the other by high airway pressure, the second attempt was successful in both cases. No subject was switched to endotracheal intubation. No laryngospasm or bronchospasm was detected. No maternal death occurred. There were 1139 neonates (including 944 single birth, 92 twins, 3 triplets) in this study, 5-min Apgar score was 7–10 in 1092 (96.72%) neonates. Thirty-seven (3.28%) neonates received endotracheal intubation. In conclusion, this retrospective study showed that the SLMA was used successfully in 1039 patients undergoing emergent cesarean delivery without any major complications. Vigilant attention by attending anesthesiologists is warranted.

Effect on Neonatal Outcome of Pharmacological Interventions for Attenuation of the Maternal Haemodynamic Response to Tracheal Intubation: A Systematic Review

The primary aim of this systematic review was to assess the effect on neonatal outcome of pharmacological interventions used for attenuation of the haemodynamic response to tracheal intubation in patients undergoing caesarean Section under general anaesthesia. A systematic search of randomised controlled trials from 1990 to 2015 was conducted. The primary outcome measure was the Apgar score at five minutes and secondary outcomes were umbilical arterial blood gas parameters and neurological adaptive capacity scores. Twenty-seven randomised controlled trials (1,689 patients) were included in the qualitative synthesis. Only five studies using opioids (383 patients) and five studies using non-opioid analgesics (358 patients) were subjected to meta-analysis. The Apgar score at five minutes was significantly lower in neonates of opioid-treated mothers (mean difference: −0.29, 95% confidence interval −0.56 to −0.02, P-value=0.03) compared to mothers in the control group; the umbilical arterial pH was lower and there was a higher requirement for tactile stimulation in neonates. No difference was seen in Apgar scores of neonates of mothers administered non-opioid analgesics compared to placebo. No difference was observed in other parameters between opioid- or non-opioid-treated mothers. This review suggests that opioid interventions for attenuation of the haemodynamic response to tracheal intubation in pregnant patients under general anaesthesia affect neonatal Apgar scores at five minutes in neonates but the difference did not appear to be clinically meaningful. We were unable to demonstrate any difference in safety.

Non-Neuraxial Labor Analgesia: Options

Although it is the most effective method to treat labor pain, neuraxial analgesia may be undesired, contraindicated, unsuccessful, or unavailable. Providing safe choices for labor pain relief is a central goal of health care providers alike. Consequently, knowledge of the efficacy, clinical implementation, and side effects of various non-neuraxial strategies is needed to provide appropriate options for laboring patients. In addition to nonpharmacologic alternatives, inhaled nitrous oxide and systemic opioids represent two broad classes of non-neuraxial pharmacologic labor analgesia most commonly available. This review summarizes the current published literature for these non-neuraxial labor analgesic options.

High-concentration sevoflurane exposure in mid-gestation induces apoptosis of neural stem cells in rat offspring

Sevoflurane is the most commonly used volatile anesthetic during pregnancy. The viability of neural stem cells directly affects the development of the brain. However, it is unknown whether the use of sevoflurane during the second trimester affects the survival of fetal neural stem cells. Therefore, in this study, we investigated whether exposure to sevoflurane in mid-gestation induces apoptosis of neural stem cells and behavioral abnormalities. On gestational day 14, pregnant rats were anesthetized with 2% or 3.5% sevoflurane for 2 hours. The offspring were weaned at 28 days and subjected to the Morris water maze test. The brains were harvested to examine neural stem cell apoptosis by immunofluorescence and to measure Nestin and SOX-2 levels by western blot assay at 6, 24 and 48 hours after anesthesia as well as on postnatal day (P) 0, 14 and 28. Vascular endothelial growth factor (VEGF) and phosphoinositide 3-kinase (PI3K)/AKT pathway protein levels in fetal brain at 6 hours after anesthesia were assessed by western blot assay. Exposure to high-concentration (3.5%) sevoflurane during mid-gestation increased escape latency and path length to the platform, and it reduced the average duration spent in the target quadrant and platform crossing times. At 6, 24 and 48 hours after anesthesia and at P0, P14 and P28, the percentage of Nestin/terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells was increased, but Nestin and SOX-2 protein levels were decreased in the hippocampus of the offspring. At 6 hours after anesthesia, VEGF, PI3K and phospho-AKT (p-AKT) levels were decreased in the fetal brain. These changes were not observed in animals given low-concentration (2%) sevoflurane exposure. Together, our findings indicate that exposure to a high concentration of sevoflurane (3.5%) in mid-gestation decreases VEGF, PI3K and p-AKT protein levels and induces neural stem cell apoptosis, thereby causing learning and memory dysfunction in the offspring.

Popliteal Sciatic Nerve Block in a Pregnant Patient in the Last Trimester

Although regional anaesthesia is a commonly preferred anaesthesia technique for pregnant patients undergoing non-obstetric surgery, peripheral nerve blocks are relatively less administered. The use of popliteal sciatic nerve block for foot-ankle surgery has been presented for a nulliparous parturient at 32 weeks of gestation scheduled to undergo surgical exploration of an arterial pseudoaneurysm on her right plantar surface due to a penetrating stab injury. Since surgery did not require pneumatic tourniquet, the sciatic nerve was blocked via the popliteal approach with a single shot injection of 30 mL of 0.375% levobupivacaine. The operation and the anaesthesia course were uneventful. In conclusion, popliteal sciatic nerve block was successful and uneventful for a short foot surgery not requiring tourniquet application in a parturient in the last trimester.

Pain-reducing anesthesia prevents oxidative stress in human term placenta

Anesthesia is sometimes used for the reduction of maternal pain in normal human term labor, but whether the drugs affect oxidative stress remains unclear. The placenta serves as an interface between the maternal and fetal vasculature. In this study, we immunohistochemically analyzed two markers for oxidative stress, namely 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal–modified proteins (HNE), using placentas from 21 cases of normal tansvaginal delivery (V group), 20 Caesarean sections (C group), and 17 normal transvaginal deliveries with epidural anesthesia (E group). 8-OHdG staining in the nuclei of trophoblasts lining the chorionic villi was significantly stronger in the V group either compared with the C or E group (p<0.001), without significant differences in the C and E groups (p = 0.792). Moderate to intense staining by HNE of the intravascular serum of chorionic villi vasculature was frequently observed in the placentas from the V group, but less frequently of those in either C or E groups (p<0.001), nor the p value comparing the C and E groups was significant (p = 0.128) for HNE staining. Our results suggest that although the role of oxidative stress and its influences on fetal state in the placenta in labor remains unclear, it seems to be lessened by epidural anesthesia.

Comparison of maternal and fetal outcomes among patients undergoing cesarean section under general and spinal anesthesia: a randomized clinical trial

CONTEXT AND OBJECTIVE

As the rates of cesarean births have increased, the type of cesarean anesthesia has gained importance. Here, we aimed to compare the effects of general and spinal anesthesia on maternal and fetal outcomes in term singleton cases undergoing elective cesarean section.

DESIGN AND SETTING

Prospective randomized controlled clinical trial in a tertiary-level public hospital.

METHODS

Our study was conducted on 100 patients who underwent cesarean section due to elective indications. The patients were randomly divided into general anesthesia (n = 50) and spinal anesthesia (n = 50) groups. The maternal pre and postoperative hematological results, intra and postoperative hemodynamic parameters and perinatal results were compared between the groups.

RESULTS

Mean bowel sounds (P = 0.036) and gas discharge time (P = 0.049) were significantly greater and 24th hour hemoglobin difference values (P = 0.001) were higher in the general anesthesia group. The mean hematocrit and hemoglobin values at the 24th hour (P = 0.004 and P < 0.001, respectively), urine volume at the first postoperative hour (P < 0.001) and median Apgar score at the first minute (P < 0.0005) were significantly higher, and the time that elapsed until the first requirement for analgesia was significantly longer (P = 0.042), in the spinal anesthesia group.

CONCLUSION

In elective cases, spinal anesthesia is superior to general anesthesia in terms of postoperative comfort. In pregnancies with a risk of fetal distress, it would be appropriate to prefer spinal anesthesia by taking the first minute Apgar score into account.

Effects of using the analgesic tramadol in mice undergoing embryo transfer surgery

Embryo transfer is a surgical technique that is widely used in reproductive biotechnology. Despite the ethical obligation to relieve animals' post-operative pain, analgesia is not routinely provided after embryo transfer surgery because it has been suggested that analgesics may be detrimental to embryo survival. Studies suggest, however, that the potential for adverse effects varies depending on the type of analgesic used and the timing of its administration. The authors carried out a study to determine whether pre-operatively administered tramadol, a synthetic analogue of codeine, influenced birth rate, litter survival or the post-operative body weights of surrogate dams. Compared with controls that were not given any analgesic, surrogate dams given tramadol had similar birth rates and similar body weights at all time points. The tramadol-treated surrogate dams showed a statistically significant increase in the number of offspring that survived to weaning. The authors conclude that pre-operatively administered tramadol does not harm the success rate of embryo transfer surgery and even may improve litter survival.

Does bupivacaine and fentanyl combination for epidural analgesia shorten the duration of labour?

In this study we aimed to explore the effects of epidural analgesia achieved by a combination of low-dose bupivacaine and fentanyl infused through an epidural catheter on mother, foetus and labour process in nulliparous at-term pregnant women during vaginal delivery. This study was designed in a prospective, randomised controlled manner. Epidural analgesia was achieved in 50 nulliparous women. Fifty nulliparous women did not undergo epidural analgesia procedure. The duration of the first stage of labour was significantly shortened, while the second stage was significantly lengthened in pregnant women who underwent epidural analgesia (p < 0.05). In conclusion, starting epidural analgesia application during the active phase of the first stage of labour may shorten the duration of the first stage compared with the group of nulliparous women not undergoing epidural analgesia. The factor that has an impact on this may be the addition of fentanyl to bupivacaine used for epidural analgesia.

[Caesarean sections under regional anesthesia: pros and cons of supplementary oxygen]

The routine administration of supplemental oxygen to women undergoing elective caesarean section under regional anesthesia in order to optimize oxygen supply to the fetus is common anesthetic practice in many German hospitals. However, this practice has been controversially discussed in the non-German literature for many years. This review presents and discusses the pros and cons of routinely providing supplemental oxygen to a parturient during caesarean section on the basis of the literature published over the last 30 years. Proponents of routine oxygen administration point to potential and unforeseeable risks of caesarean sections and consider the prophylactic administration of oxygen based on physiological considerations to be advantageous in terms of patient safety. Interestingly, data regarding the effects of an increased maternal FIO2 on improvement of fetal oxygenation are inconsistent, therefore, no unambiguous recommendation concerning which FIO2 to choose can be given. Opponents of routine oxygen supplementation allude above all to an increase in free radical activity in both mother and fetus; however, data in this respect are not consistent either. As supplemental oxygen to patients undergoing elective caesarean section without any risk factors under regional anesthesia is associated with potential risks while no advantage has so far been demonstrated, routine administration of oxygen has to be challenged and is no longer considered to be indicated by many. On the contrary, in cases of emergency with a concomitant risk of hypoxia for mother and fetus, administration of oxygen is indispensable in the light of present data.

The median effective volume of crystalloid in preventing hypotension in patients undergoing cesarean delivery with spinal anesthesia

BACKGROUND AND OBJECTIVES

Spinal anesthesia-associated maternal hypotension in Cesarean delivery is the most frequent and troublesome complication, posing serious risks to mothers and compromising neonatal well-being. The effective volume of intravenous crystalloid as the preventive strategy in this context has not been estimated.

METHODS

Eighty-five parturients with ASA physical status I/II undergoing elective Cesarean delivery were screened and 67 eligible women were assigned to receive pre-spinal crystalloid loading. Hyperbaric 0.5% bupivacaine 2mL (10mg) plus morphine 50μg was given to all patients. The volume of crystalloid was determined by an up-and-down sequential method. The crystalloid was infused at a rate of 100-150mL.min(-1) prior to the spinal anesthetic injection. The initial volume of crystalloid was 5mL.kg(-1). Volume-effect data were fitted to a sigmoidal maximum efficacy model and the median effective volume (EV(50)) and corresponding 95% confidence interval (95% CI) were estimated using maximum likelihood estimation and logistic regression with Firth's correction.

RESULTS

A total of 67 subjects completed the study and were analyzed. Twenty-eight (41.8%) patients developed hypotension with their systolic blood pressure (SBP) decreasing > 20% of baseline. The EV(50) of crystalloid were 12.6mL.kg(-1) (95% CI, 11.6 to 14.8mL.kg(-1)). With Firth's correction, the pooled probability of an effective preventive volume of crystalloid at 13mL.kg(-1) was 50.2% (95% CI, 30% to 83.1%).

CONCLUSIONS

The estimated EV(50) of the preloaded crystalloid required to prevent spinal anesthesia-induced hypotension in a Cesarean section is, approximately, 13mL.kg(-1). However, prophylactic or therapeutic vasoconstrictors should also be prepared and administered at an appropriate time.

Maternal and neonatal effects of nalbuphine given immediately before induction of general anesthesia for elective cesarean section

BACKGROUND

Although nalbuphine was studied extensively in labour analgesia and was proved to be acceptable analgesics during delivery, its use as premedication before induction of general anesthesia for cesarean section is not studied. The aim of this study was to evaluate the effect of nalbuphine given before induction of general anesthesia for cesarean section on quality of general anesthesia, maternal stress response, and neonatal outcome.

METHODS

Sixty full term pregnant women scheduled for elective cesarean section, randomly classified into two equal groups, group N received nalbuphine 0.2 mg/kg diluted in 10 ml of normal saline (n=30), and group C placebo (n=30) received 10 ml of normal saline 1 min before the induction of general anesthesia. Maternal heart rate and blood pressure were measured before, after induction, during surgery, and after recovery. Neonates were assisted by using APGAR0 scores, time to sustained respiration, and umbilical cord blood gas analysis.

RESULT

Maternal heart rate showed significant increase in control group than nalbuphine group after intubation (88.2±4.47 versus 80.1±4.23, P<0.0001) and during surgery till delivery of baby (90.8±2.39 versus 82.6±2.60, P<0.0001) and no significant changes between both groups after delivery. MABP increased in control group than nalbuphine group after intubation (100.55±6.29 versus 88.75±6.09, P<0.0001) and during surgery till delivery of baby (98.50±2.01 versus 90.50±2.01, P<0.0001) and no significant changes between both groups after delivery. APGAR score was significantly low at one minute in nalbuphine group than control group (6.75±2.3, 8.5±0.74, respectively, P=0.0002) (27% of nalbuphine group APGAR score ranged between 4-6, while 7% in control group APGAR score ranged between 4-6 at one minute). All neonates at five minutes showed APGAR score ranged between 9-10. Time to sustained respiration was significantly longer in nalbuphine group than control group (81.8±51.4 versus 34.9±26.2 seconds, P<0.0001). The umbilical cord blood gas was comparable in both groups. None of the neonates need opioid antagonist (naloxone) or endotracheal intubation.

CONCLUSION

Administration of nalbuphine before cesarean section under general anesthesia reduces maternal stress response related to intubation and surgery, but decreases the APGAR score at one minute after delivery. So, when nalbuphine was used, all measures for neonatal monitoring and resuscitation must be available including attendance of a pediatrician.

Impact of anesthetic methods on neonatal outcome in women receiving temporary balloon occlusion of the common iliac artery during cesarean section for placenta accreta

OBJECTIVE

Placenta accreta is associated with significant maternal morbidity and is the leading indication for peripartum hysterectomy. In our institution, occlusion balloon catheters are commonly placed in bilateral common iliac arteries in order to reduce blood loss and facilitate surgery in patients with this obstetric complication. Few studies, however, have evaluated the effect of different anesthetic methods for cesarean hysterectomy on neonatal outcome. In this study, we compared Apgar scores among neonates born to mothers under general anesthesia with those who received regional anesthesia.

CASE REPORTS

A retrospective analysis of 19 women with placenta accreta/percreta who underwent cesarean hysterectomy in our hospital, revealed that the 1-minute Apgar score was <7 in 4/12 neonates born to women who underwent general anesthesia and in 1/7 neonates born to mothers who received regional anesthesia. The 5-minute Apgar score was >7 after immediate resuscitation in all neonates. There were no significant differences in demographic data, induction-to-delivery period, or Apgar scores between the general and the regional anesthesia groups.

CONCLUSION

We acknowledge that the retrospective nature of this study makes it difficult to conclude whether the different anesthesia management strategies had an impact on Apgar score; however, according to our clinical observation, regional anesthesia may be a better alternative in the induction-to-delivery period, especially for women with accreta/percreta and in situations in which poor neonatal outcome is expected.

The new challenging pediatric patient

The 'new' challenging pediatric patients are those who could be called 'the survivors' and neonates undergoing birth under materno-fetal circulation. Their anesthetic management is complex because their initial pathology was previously lethal: the physiologic, pharmacologic, and or technical aspect of their management is presently unknown or hypothetical. Some examples are described. Communication with the pediatrician in charge of the child is the key to safe and effective anesthetic care of these cases.

Pain management for women in labour: an overview of systematic reviews

BACKGROUND

The pain that women experience during labour is affected by multiple physiological and psychosocial factors and its intensity can vary greatly.  Most women in labour require pain relief. Pain management strategies include non-pharmacological interventions (that aim to help women cope with pain in labour) and pharmacological interventions (that aim to relieve the pain of labour).

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on the efficacy and safety of non-pharmacological and pharmacological interventions to manage pain in labour. We considered findings from non-Cochrane systematic reviews if there was no relevant Cochrane review.

METHODS

We searched the Cochrane Database of Systematic Reviews (The Cochrane Library 2011, Issue 5), The Cochrane Database of Abstracts of Reviews of Effects (The Cochrane Library 2011, Issue 2 of 4), MEDLINE (1966 to 31 May 2011) and EMBASE (1974 to 31 May 2011) to identify all relevant systematic reviews of randomised controlled trials of pain management in labour. Each of the contributing Cochrane reviews (nine new, six updated) followed a generic protocol with 13 common primary efficacy and safety outcomes. Each Cochrane review included comparisons with placebo, standard care or with a different intervention according to a predefined hierarchy of interventions. Two review authors extracted data and assessed methodological quality, and data were checked by a third author. This overview is a narrative summary of the results obtained from individual reviews.

MAIN RESULTS

We identified 15 Cochrane reviews (255 included trials) and three non-Cochrane reviews (55 included trials) for inclusion within this overview. For all interventions, with available data, results are presented as comparisons of: 1. Intervention versus placebo or standard care; 2. Different forms of the same intervention (e.g. one opioid versus another opioid); 3. One type of intervention versus a different type of intervention (e.g. TENS versus opioid). Not all reviews included results for all comparisons. Most reviews compared the intervention with placebo or standard care, but with the exception of opioids and epidural analgesia, there were few direct comparisons between different forms of the same intervention, and even fewer comparisons between different interventions. Based on these three comparisons, we have categorised interventions into: " What works" ,"What may work", and "Insufficient evidence to make a judgement".WHAT WORKSEvidence suggests that epidural, combined spinal epidural (CSE) and inhaled analgesia effectively manage pain in labour, but may give rise to adverse effects. Epidural, and inhaled analgesia effectively relieve pain when compared with placebo or a different type of intervention (epidural versus opioids). Combined-spinal epidurals relieve pain more quickly than traditional or low dose epidurals. Women receiving inhaled analgesia were more likely to experience vomiting, nausea and dizziness.When compared with placebo or opioids, women receiving epidural analgesia had more instrumental vaginal births and caesarean sections for fetal distress, although there was no difference in the rates of caesarean section overall. Women receiving epidural analgesia were more likely to experience hypotension, motor blockade, fever or urinary retention. Less urinary retention was observed in women receiving CSE than in women receiving traditional epidurals. More women receiving CSE than low-dose epidural experienced pruritus.  WHAT MAY WORKThere is some evidence to suggest that immersion in water, relaxation, acupuncture, massage and local anaesthetic nerve blocks or non-opioid drugs may improve management of labour pain, with few adverse effects.  Evidence was mainly limited to single trials. These interventions relieved pain and improved satisfaction with pain relief (immersion, relaxation, acupuncture, local anaesthetic nerve blocks, non-opioids) and childbirth experience (immersion, relaxation, non-opioids) when compared with placebo or standard care. Relaxation was associated with fewer assisted vaginal births and acupuncture was associated with fewer assisted vaginal births and caesarean sections.INSUFFICIENT EVIDENCEThere is insufficient evidence to make judgements on whether or not hypnosis, biofeedback, sterile water injection, aromatherapy, TENS, or parenteral opioids are more effective than placebo or other interventions for pain management in labour. In comparison with other opioids more women receiving pethidine experienced adverse effects including drowsiness and nausea. 

AUTHORS' CONCLUSIONS

Most methods of non-pharmacological pain management are non-invasive and appear to be safe for mother and baby, however, their efficacy is unclear, due to limited high quality evidence. In many reviews, only one or two trials provided outcome data for analysis and the overall methodological quality of the trials was low. High quality trials are needed.There is more evidence to support the efficacy of pharmacological methods, but these have more adverse effects. Thus, epidural analgesia provides effective pain relief but at the cost of increased instrumental vaginal birth.It remains important to tailor methods used to each woman's wishes, needs and circumstances, such as anticipated duration of labour, the infant's condition, and any augmentation or induction of labour.A major challenge in compiling this overview, and the individual systematic reviews on which it is based, has been the variation in use of different process and outcome measures in different trials, particularly assessment of pain and its relief, and effects on the neonate after birth. This made it difficult to pool results from otherwise similar studies, and to derive conclusions from the totality of evidence. Other important outcomes have simply not been assessed in trials; thus, despite concerns for 30 years or more about the effects of maternal opioid administration during labour on subsequent neonatal behaviour and its influence on breastfeeding, only two out of 57 trials of opioids reported breastfeeding as an outcome. We therefore strongly recommend that the outcome measures, agreed through wide consultation for this project, are used in all future trials of methods of pain management.

Epidural analgesia during labor vs no analgesia: A comparative study

BACKGROUND

Epidural analgesia is claimed to result in prolonged labor. Previous studies have assessed epidural analgesia vs systemic opioids rather than to parturients receiving no analgesia. This study aimed to evaluate the effect of epidural analgesia on labor duration compared with parturients devoid of analgesia.

METHODS

One hundred sixty nulliparous women in spontaneous labor at full term with a singleton vertex presentation were assigned to the study. Parturients who request epidural analgesia were allocated in the epidural group, whereas those not enthusiastic to labor analgesia were allocated in the control group. Epidural analgesia was provided with 20 mL bolus 0.5% epidural lidocaine plus fentanyl and maintained at 10 mL for 1 h. Duration of the first and second stages of labor, number of parturients receiving oxytocin, maximal oxytocin dose required for each parturient, numbers of instrumental vaginal, vacuum-assisted, and cesarean deliveries and neonatal Apgar score were recorded.

RESULTS

There was no statistical difference in the duration of the active-first and the second stages of labor, instrumental delivery, vacuum-assisted or cesarean delivery rates, the number of newborns with 1-min and 5-min Apgar scores less than 7 between both groups and number of parturients receiving oxytocin, however, the maximal oxytocin dose was significantly higher in the epidural group.

CONCLUSION

Epidural analgesia by lidocaine (0.5%) and fentanyl does not prolong labor compared with parturients without analgesia; however, significant oxytocin augmentation is required during the epidural analgesia to keep up the aforementioned average labor duration.

Update in fetal anesthesia for the ex utero intrapartum treatment (EXIT) procedure

The ex-utero intrapartum treatment (EXIT) is one type of fetal surgery, performed before delivery while the fetus remains attached to the uteroplacental circulation. This intervention improves neonatal morbidity and mortality of certain congenital diseases. For instance, securing the airway of a fetus with congenital airway obstruction while on uteroplacental circulation prevents the hypoxemia during the establishment of an airway post-delivery. Anesthesia for fetal surgery now incorporates new knowledge of the maternal/fetal response to anesthetic agents. This chapter reviews for the EXIT procedure the effects of maternal anesthesia on fetal hemodynamics, intravenous anesthesia to supplement inhalational anesthesia in order to provide maternal-fetal hemodynamic stability during surgery, intraoperative fetal monitoring, maternal pharmacokinetics approach to study placental drug transfer and fetal pharmacokinetics to improve our understanding of the effects of maternal anesthesia on the fetus.

The Effects of Colloid Pre-Loading on Thromboelastography Prior to Caesarean Delivery: Hydroxyethyl Starch 130/0.4 versus Succinylated Gelatine

This prospective, randomized, double-blind study compared the effects on thromboelastography (TEG) of preloading with two different colloid fluids prior to spinal anaesthesia for caesarean section. Healthy full-term parturients received either 500 ml 6% hydroxyethyl starch 130/0.4 (HES, n = 25) or 500 ml 4% succinylated gelatine (GEL, n = 25) prior to spinal anaesthesia. TEG parameters including reaction time (r-time), clot formation time (k-time), clot formation rate (α-angle) and maximum amplitude (MA) were measured immediately before and after pre-loading. Both groups had significantly shorter r-time and lower MA after pre-loading. The α-angle was significantly decreased after pre-loading with HES but not with GEL. No significant differences in k-time were induced pre-loading. In conclusion, preloading with HES or GEL was associated with a mild hypocoagulable effect in healthy parturients presenting for elective caesarean section; however, all TEG parameters in both groups remained within or very close to the normal range after pre-loading.

Maternal hypotension during elective cesarean section and short-term neonatal outcome

OBJECTIVE

To investigate the extent and risk factors for hypotension among women undergoing elective cesarean section, and whether maternal hypotension has any impact on perinatal infant outcome.

STUDY DESIGN

Retrospective analysis of data on 919 mother-infant pairs after elective cesarean section that involved the use of regional anesthetic. Data collection included information on maternal blood pressure during the cesarean section procedure and any infant perinatal complications.

RESULTS

Nearly one-half of the mothers underwent a decrease in their mean arterial blood pressure by > or =30%. The risk factors for hypotension included preoperative hypertension, older age, type of spinal anesthesia, and a higher infant birthweight. A drop in the maternal mean arterial blood pressure exceeding 30% or even 50% compared with the preoperative value was not found to predict any perinatal complications.

CONCLUSION

Despite a very high prevalence of maternal hypotension during cesarean sections, term infants tend to tolerate this placental blood perfusion challenge without any major sequel.

Educational intervention for obstetrical nurses: introducing intravenous fentanyl to the labour floor

OBJECTIVE

To determine the efficacy of an educational intervention in changing nurses' satisfaction and comfort with and their knowledge and use of a newly introduced analgesic agent, fentanyl, to manage pain during labour.

METHODS

A written survey was completed by 19 labour and delivery nurses before and after the educational intervention in a small Northern Canadian city.

RESULTS

Prior to the educational intervention, respondents rated their knowledge of and comfort with use of morphine and meperidine as significantly greater than their knowledge of and comfort with use of fentanyl (P<0.001 for all comparisons). Following the educational intervention, their knowledge and comfort with use of fentanyl increased to the same level as their knowledge and comfort with use of morphine and meperidine. Knowledge of and comfort with use of morphine and meperidine did not change after the educational intervention, but with use of fentanyl there was a significant increase in both knowledge (P<0.001) and comfort (P<0.001). Use of fentanyl subsequently increased significantly (P=0.016) and the nurses identified fewer barriers to its use. Satisfaction with (and self-reported use of) fentanyl also increased (P=0.001).

CONCLUSION

Participation in education regarding fentanyl increased nurses' knowledge of and comfort and satisfaction with this agent. It also contributed to an increase in the use of this agent, which has been documented to be safer than other narcotics for both mother and baby.

Persistent changes in arterial blood gases in fetal sheep

Two anaesthetic protocols were compared using pregnant sheep. In both groups of animals, anaesthesia was induced using an intravenous (i.v.) injection of diazepam and ketamine. The ewes were then intubated for positive pressure ventilation using 0.8 L/min of nitrous oxide and 2 L/min oxygen with 1.1-1.8% halothane. If the ewe showed any signs of awakening, one of two protocols was followed. First, the halothane concentration was increased to 2-3% until the ewe was completely anaesthetized. Second, the halothane concentration was not altered, but the ewe was given doses of i.v. diazepam (0.1 mg/kg) and ketamine (1 mg/kg) until again completely anaesthetized. At the completion of surgery, maternal recovery was rapid and similar between the two groups. However, five days after surgery, the fetal arterial Po(2) and oxygen content of the fetuses receiving additional halothane (1.9 +/- 0.2 kPa and 4.4 +/- 1.0 mL/100 mL) were statistically significantly depressed when compared with the fetuses receiving additional diazepam and ketamine (2.9 +/- 0.1 kPa and 7.0 +/- 0.5 mL/100 mL). These results led us to conclude that certain anaesthetic protocols, in spite of good maternal recovery, can lead to deleterious effects upon the fetus that persist for at least five days after surgery.

Remifentanil for cesarean section under general anesthesia: effects on maternal stress hormone secretion and neonatal well-being: a randomized trial

BACKGROUND

Remifentanil may attenuate maternal hemodynamic response during cesarean section under general anesthesia, but could cause transient but significant neonatal depression. We investigated the effect of low-dose remifentanil on maternal neuroendocrine response and fetal wellbeing.

METHODS

Forty-two ASA I-II parturients undergoing cesarean section at term under general anesthesia were randomized to receive either fentanyl after delivery (n=21, group C) or remifentanil bolus 0.5 microg/kg before induction followed by a continuous infusion at 0.15 microg x kg(-1)min(-1) until peritoneal incision, then restarted after delivery (n=21, group R). Maternal heart rate and blood pressure, and epinephrine, norepinephrine, adrenocorticotropic hormone (ACTH), and growth hormone levels were measured at baseline, uterine incision, and the end of surgery. Remifentanil was measured in maternal and umbilical arterial and venous blood. One- and 5-minute Apgar scores and umbilical arterial and venous pH were recorded.

RESULTS

ACTH was significantly higher in group C at uterine incision (P<0.01). No significant differences were observed in hemodynamics, catecholamines or growth hormone. Apgar scores at 1 (P<0.05) and 5 min (P<0.01) were significantly higher in group C. Mean umbilical pH values were within normal range but significantly higher in group C. Three neonates in group R required intubation but recovered at 5 min without naloxone. Mean+/-SD maternal remifentanil concentration was 1.67+/-1.04 ng/mL.

CONCLUSIONS

Remifentanil administration before peritoneal incision partially reduced the hormonal stress response. Maternal benefits must be weighed against transitory but significant neonatal respiratory depression. Neonatal resuscitation facilities are mandatory when remifentanil is used.

Maternal and neonatal outcome after cesarean section: the impact of anesthesia

BACKGROUND

Among the anesthetic technologies used, regional anesthesia is becoming the most common in cesarean section (CS) deliveries. Aim. This retrospective survey examined the variables taken into account when selecting the anesthetic technique to be used, and how this choice affects the outcome for the mother and the newborn.

METHODS

One thousand eight hundred and seventy elective and emergency CS were evaluated for anesthetic technique used, indications, and maternal and neonatal outcome.

RESULTS

Of the 611 elective CS (32.6%), 206 (33.8%) were performed under general anesthesia and 405 (66.2%) under regional anesthesia. Of the 1259 emergency CS performed (67.4%), 525 (41.9%) were under general anesthesia and 734 (58.1%) under regional anesthesia. Conditions associated with a newborn 1-minute Apgar score of <7 were general anesthesia and multiple pregnancy (p<0.01); a 5-minute Apgar score of <7 was only associated with multiple pregnancy. The most important factor for very low Apgar scores was the presence of fetal malformations. Whatever the chosen technique, neither maternal deaths directly or indirectly due to the anesthesia nor major maternal and perinatal complications were found.

CONCLUSIONS

This survey confirms the preference for regional anesthesia during elective cesarean sections and for general anesthesia in emergency situations. Moreover, newborn outcome was found not to be influenced either by the technique used or by the character of the procedure.

Evidence-based practices for the fetal to newborn transition

Many common care practices during labor, birth, and the immediate postpartum period impact the fetal to neonatal transition, including medication used during labor, suctioning protocols, strategies to prevent heat loss, umbilical cord clamping, and use of 100% oxygen for resuscitation. Many of the care practices used to assess and manage a newborn immediately after birth have not proven efficacious. No definitive outcomes have been obtained from studies on maternal analgesia effects on the newborn. Although immediate cord clamping is common practice, recent evidence from large randomized, controlled trials suggests that delayed cord clamping may protect the infant against anemia. Skin-to-skin care of the newborn after birth is recommended as the mainstay of newborn thermoregulation and care. Routine suctioning of infants at birth was not been found to be beneficial. Neither amnioinfusion, suctioning of meconium-stained babies after the birth of the head, nor intubation and suctioning of vigorous infants prevents meconium aspiration syndrome. The use of 100% oxygen at birth to resuscitate a newborn causes increased oxidative stress and does not appear to offer benefits over room air. This review of evidence on newborn care practices reveals that more often than not, less intervention is better. The recommendations support a gentle, physiologic birth and family-centered care of the newborn.