Effects of Pregnancy Anesthesia on Fetal Nervous System

Effects of mid‑gestational sevoflurane and magnesium sulfate on maternal oxidative stress, inflammation and fetal brain histopathology

Models of inflammation, oxidative stress, hyperoxia and hypoxia have demonstrated that magnesium sulfate (MgSO4), a commonly used drug in obstetrics, has neuroprotective potential. In the present study, the effects of MgSO4 treatment on inflammation, oxidative stress and fetal brain histopathology were evaluated in an experimental rat model following sevoflurane (Sv) exposure during the mid-gestational period. Rats were randomly divided into groups: C (control; no injections or anesthesia), Sv (exposure to 2.5% Sv for 2 h), MgSO4 (administered 270 mg/kg MgSO4 intraperitoneally) and Sv + MgSO4 (Sv administered 30 min after MgSO4 injection). Inflammatory and oxidative stress markers were measured in the serum and neurotoxicity was investigated histopathologically in fetal brain tissue. Short-term mid-gestational exposure to a 1.1 minimum alveolar concentration of Sv did not significantly increase the levels of any of the measured biochemical markers, except for TNF-α. Histopathological evaluations demonstrated no findings suggestive of pathological apoptosis, neuroinflammation or oxidative stress-induced cell damage. MgSO4 injection prior to anesthesia caused no significant differences in biochemical or histopathological marker levels compared to the C and Sv groups. The present study indicated that short-term exposure to Sv could potentially be considered a harmless external stimulus to the fetal brain.

Reduced fetal cerebral blood flow predicts perinatal mortality in a mouse model of prenatal alcohol and cannabinoid exposure

BACKGROUND

Children exposed prenatally to alcohol or cannabinoids individually can exhibit growth deficits and increased risk for adverse birth outcomes. However, these drugs are often co-consumed and their combined effects on early brain development are virtually unknown. The blood vessels of the fetal brain emerge and mature during the neurogenic period to support nutritional needs of the rapidly growing brain, and teratogenic exposure during this gestational window may therefore impair fetal cerebrovascular development.

STUDY DESIGN

To determine whether prenatal polysubstance exposure confers additional risk for impaired fetal-directed blood flow, we performed high resolution in vivo ultrasound imaging in C57Bl/6J pregnant mice. After pregnancy confirmation, dams were randomly assigned to one of four groups: drug-free control, alcohol-exposed, cannabinoid-exposed or alcohol-and-cannabinoid-exposed. Drug exposure occurred daily between Gestational Days 12-15, equivalent to the transition between the first and second trimesters in humans. Dams first received an intraperitoneal injection of either cannabinoid agonist CP-55,940 (750 µg/kg) or volume-equivalent vehicle. Then, dams were placed in vapor chambers for 30 min of inhalation of either ethanol or room air. Dams underwent ultrasound imaging on three days of pregnancy: Gestational Day 11 (pre-exposure), Gestational Day 13.5 (peri-exposure) and Gestational Day 16 (post-exposure).

RESULTS

All drug exposures decreased fetal cranial blood flow 24-hours after the final exposure episode, though combined alcohol and cannabinoid co-exposure reduced internal carotid artery blood flow relative to all other exposures. Umbilical artery metrics were not affected by drug exposure, indicating a specific vulnerability of fetal cranial circulation. Cannabinoid exposure significantly reduced cerebroplacental ratios, mirroring prior findings in cannabis-exposed human fetuses. Post-exposure cerebroplacental ratios significantly predicted subsequent perinatal mortality (p = 0.019, area under the curve, 0.772; sensitivity, 81%; specificity, 85.70%) and retroactively diagnosed prior drug exposure (p = 0.005; AUC, 0.861; sensitivity, 86.40%; specificity, 66.7%).

CONCLUSIONS

Fetal cerebrovasculature is significantly impaired by exposure to alcohol or cannabinoids, and co-exposure confers additional risk for adverse birth outcomes. Considering the rising potency and global availability of cannabis products, there is an imperative for research to explore translational models of prenatal drug exposure, including polysubstance models, to inform appropriate strategies for treatment and care in pregnancies affected by drug exposure.

Angelicin Alleviates Maternal Isoflurane Exposure-Induced Offspring Cognitive Defects Through the Carbonic Anhydrase 4/Aquaporin-4 Pathway

An increasing number of studies reveal the deleterious effects of isoflurane (Iso) exposure during pregnancy on offspring cognition. However, no effective therapeutic strategy for Iso-induced deleterious effects has been well developed. Angelicin exerts an anti-inflammatory effect on neurons and glial cells. This study investigated the roles and mechanism of action of angelicin in Iso-induced neurotoxicity in vitro and in vivo. After exposing C57BL/6 J mice on embryonic day 15 (E15) to Iso for 3 and 6 h, respectively, neonatal mice on embryonic day 18 (E18) displayed obvious anesthetic neurotoxicity, which was revealed by the elevation of cerebral inflammatory factors and blood-brain barrier (BBB) permeability and cognitive dysfunction in mice. Angelicin treatment could not only significantly reduce the Iso-induced embryonic inflammation and BBB disruption but also improve the cognitive dysfunction of offspring mice. Iso exposure resulted in an increase of carbonic anhydrase (CA) 4 and aquaporin-4 (AQP4) expression at both mRNA and protein levels in vascular endothelial cells and mouse brain tissue collected from neonatal mice on E18. Remarkably, the Iso-induced upregulation of CA4 and AQP4 expression could be partially reversed by angelicin treatment. Moreover, GSK1016790A, an AQP4 agonist, was used to confirm the role of AQP4 in the protective effect of angelicin. Results showed that GSK1016790A abolished the therapeutic effect of angelicin on Iso-induced inflammation and BBB disruption in the embryonic brain and on the cognitive function of offspring mice. In conclusion, angelicin may serve as a potential therapeutic for Iso-induced neurotoxicity in neonatal mice by regulating the CA4/AQP4 pathway.

Awake craniotomy during pregnancy: A systematic review of the published literature

Neurosurgical pathologies in pregnancy pose significant complications for the patient and fetus, and physiological stressors during anesthesia and surgery may lead to maternal and fetal complications. Awake craniotomy (AC) can preserve neurological functions while reducing exposure to anesthetic medications. We reviewed the literature investigating AC during pregnancy. PubMed, Scopus, and Web of Science databases were searched from the inception to February 7th, 2023, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Studies in English investigating AC in pregnant patients were included in the final analysis. Nine studies composed of nine pregnant patients and ten fetuses (one twin-gestating patient) were included. Glioma was the most common pathology reported in six (66.7%) patients. The frontal lobe was the most involved region (4 cases, 44.4%), followed by the frontoparietal region (2 cases, 22.2%). The awake-awake-awake approach was the most common protocol in seven (77.8%) studies. The shortest operation time was two hours, whereas the longest one was eight hours and 29 min. The mean gestational age at diagnosis was 13.6 ± 6.5 (2-22) and 19.6 ± 6.9 (9-30) weeks at craniotomy. Seven (77.8%) studies employed intraoperative fetal heart rate monitoring. None of the AC procedures was converted to general anesthesia. Ten healthy babies were delivered from patients who underwent AC. In experienced hands, AC for resection of cranial lesions of eloquent areas in pregnant patients is safe and feasible and does not alter the pregnancy outcome.

Up-to-date literature review and issues of sedation during digestive endoscopy

Sedation is common during digestive endoscopy to provide comfort and pain relief for patients. However, the use of sedation in endoscopy also poses potential risks, and recent issues have been raised regarding its safety and administration. This literature review paper will discuss the most recent developments in the field of sedation in digestive endoscopy, including the adverse events that might be associated with sedation and how to manage it, the legal issues associated with administration, the impact of COVID-19 on sedation practices, and sedation in special situations. It will also touch upon the current guidelines and recommendations for sedation, including the importance of patient selection and monitoring and the need for training and certification for endoscopists administering sedation. The review will also analyse studies evaluating the safety and efficacy of various sedation techniques, including propofol, midazolam, and others. It will examine the benefits and drawbacks of these agents.

Prenatal anesthetic exposure and offspring neurodevelopmental outcomes—A narrative review

While it is common for pregnant women to take anesthesia during surgery, the effects of prenatal anesthesia exposure (PAE) on the long-term neurodevelopment of the offspring remain to be clarified. Preclinical animal research has shown that in utero anesthetic exposure causes neurotoxicity in newborns, which is mainly characterized by histomorphological changes and altered learning and memory abilities. Regional birth cohort studies that are based on databases are currently the most convenient and popular types of clinical studies. Specialized questionnaires and scales are usually employed in these studies for the screening and diagnosis of neurodevelopmental disorders in the offspring. The time intervals between the intrauterine exposure and the onset of developmental outcomes often vary over several years and accommodate a large number of confounding factors, which have an even greater impact on the neurodevelopment of the offspring than prenatal anesthesia itself. This narrative review summarized the progress in prenatal anesthetic exposure and neurodevelopmental outcomes in the offspring from animal experimental research and clinical studies and provided a brief introduction to assess the neurodevelopment in children and potential confounding factors.

Anaesthetic management of cerebral arteriovenous malformation hemorrhage during pregnancy: A case series

RATIONALE

There is no clear consensus guidance for anesthesiologists on how to manage patients with cerebral arteriovenous malformation (cAVM) rupture and hemorrhage during pregnancy who need craniotomy. Our objective was to review the anesthesia management of pregnant women who underwent resection of cAVM at our institution and to provide opinions and suggestions.

PATIENT CONCERNS

Herein, we report of 3 patients with cAVM rupture and hemorrhage during pregnancy who underwent neurosurgery at the 22nd, 28th, and 20th weeks of pregnancy.

DIAGNOSES

All 3 patients were admitted to the emergency department of our hospital due to sudden symptoms. Subsequently, their head imaging results confirmed the rupture and hemorrhage of cAVM. The rupture and hemorrhage of cAVM during pregnancy has a low incidence and high mortality, which seriously endangers the safety of the mother and fetus. For this emergency condition, craniotomy for removing intracranial lesions and clear hematoma can result in a chance of a successful delivery. Especially in the second and third trimesters of pregnancy, the management goal of anesthesia is to ensure the maternofetal safety and to maintain continuous pregnancy.

INTERVENTIONS

This article describes the process of intraoperative anesthesia management and maternal-fetal outcomes and discusses the key issues for the anesthesia management of cAVM rupture during pregnancy, including considerations of physiological changes during pregnancy and anesthesia medication, intraoperative monitoring, the maintenance of hemodynamic stability, and the control of intracranial pressure, among other considerations. Resection of intracranial lesions should be performed whenever possible while maintaining the pregnancy for better maternal and infant outcomes.

OUTCOMES

The operations of the 3 pregnant women were successfully completed under our detailed anesthesia planning and careful anesthesia management. All the patients recovered well after the operation, and underwent cesarean section to give birth smoothly.

LESSONS

The preservation of pregnancy under cAVM resection is a complex challenge for anesthesiologists, and these 3 cases provide an extensive amount of experience for anesthesia management in similar situations. Detailed anesthesia planning and careful anesthesia management by anesthesiologists are important guarantees for good maternal and fetal outcomes.

Hematuria in pregnancy due to renal arteriovenous malformation: A case report

A 31-year-old pregnant woman at 22 weeks and 2 days of gestation presented to the emergency room with complaints of painless hematuria and passage of clots. Initial computed tomography angiography (CTA) of the abdomen and pelvis performed after ultrasound revealed evidence of blood products in the bladder. However, the CTA did not reveal any source of bleeding. Given hemodynamic instability and persistent pain, the patient was taken to the operating room for a cystoscopy, which revealed bleeding from the left renal unit, giving rise to suspicion of a renal arteriovenous malformation (AVM). The patient then underwent left renal digital subtraction angiography (DSA), which produced no evidence of active bleeding. Due to high clinical suspicion and ongoing symptomatic hematuria, she underwent DSA a second time, which did demonstrate renal AVM bleeding, and embolization was performed. This case highlights the importance of cystoscopy in diagnosing a renal AVM in a pregnant patient despite the risks of general anesthesia during pregnancy.

•

Diagnosis of renal arteriovenous malformations during pregnancy can be difficult.

•

A high index of suspicion is necessary to diagnose renal arteriovenous malformation.

•

Diagnosis and management of a woman at 22 weeks of gestation are described.

•

The patient subsequently had an uneventful pregnancy and delivered at term.