Effect of Spinal Anesthesia versus General Anesthesia on Blood Glucose Concentration in Patients Undergoing Elective Cesarean Section Surgery: A Prospective Comparative Study

Monolacunary Wells-Dawson Polyoxometalate as a Novel Contrast Agent for Computed Tomography: A Comprehensive Study on In Vivo Toxicity and Biodistribution

Polyoxotungstate nanoclusters have recently emerged as promising contrast agents for computed tomography (CT). In order to evaluate their clinical potential, in this study, we evaluated the in vitro CT imaging properties, potential toxic effects in vivo, and tissue distribution of monolacunary Wells-Dawson polyoxometalate, α2-K10P2W17O61.20H2O (mono-WD POM). Mono-WD POM showed superior X-ray attenuation compared to other tungsten-containing nanoclusters (its parent WD-POM and Keggin POM) and the standard iodine-based contrast agent (iohexol). The calculated X-ray attenuation linear slope for mono-WD POM was significantly higher compared to parent WD-POM, Keggin POM, and iohexol (5.97 ± 0.14 vs. 4.84 ± 0.05, 4.55 ± 0.16, and 4.30 ± 0.09, respectively). Acute oral (maximum-administered dose (MAD) = 960 mg/kg) and intravenous administration (1/10, 1/5, and 1/3 MAD) of mono-WD POM did not induce unexpected changes in rats' general habits or mortality. Results of blood gas analysis, CO-oximetry status, and the levels of electrolytes, glucose, lactate, creatinine, and BUN demonstrated a dose-dependent tendency 14 days after intravenous administration of mono-WD POM. The most significant differences compared to the control were observed for 1/3 MAD, being approximately seventy times higher than the typically used dose (0.015 mmol W/kg) of tungsten-based contrast agents. The highest tungsten deposition was found in the kidney (1/3 MAD-0.67 ± 0.12; 1/5 MAD-0.59 ± 0.07; 1/10 MAD-0.54 ± 0.05), which corresponded to detected morphological irregularities, electrolyte imbalance, and increased BUN levels.

In vivo toxicity evaluation of a polyoxotungstate nanocluster as a promising contrast agent for computed tomography

In this study, we demonstrate for the first time, that a discrete metal-oxo cluster α-/β-K₆P₂W₁₈O₆₂ (WD-POM) exhibits superior performance as a computed tomography (CT) contrast agent, in comparison to the standard contrast agent iohexol. A toxicity evaluation of WD-POM was performed according to standard toxicological protocols using Wistar albino rats. The maximum tolerable dose (MTD) of 2000 mg/kg was initially determined after oral WD-POM application. The acute intravenous toxicity of single WD-POM doses (1/3, 1/5, and 1/10 MTD), which are at least fifty times higher than the typically used dose (0.015 mmol W kg^-1) of tungsten-based contrast agents, was evaluated for 14 days. The results of arterial blood gas analysis, CO-oximetry status, electrolyte and lactate levels for 1/10 MTD group (80% survival rate) indicated the mixed respiratory and metabolic acidosis. The highest deposition of WD-POM (0.6 ppm tungsten) was found in the kidney, followed by liver (0.15 ppm tungsten), for which the histological analysis revealed morphological irregularities, although the renal function parameters (creatinine and BUN levels) were within the physiological range. This study is the first and important step in evaluating side effects of polyoxometalate nanoclusters, which in recent years have shown a large potential as therapeutics and contrast agents.

Hypoglycemia as a cause of sudden cardiac arrest during cesarean delivery under spinal anesthesia: a case report and review of the literature

Background

Sudden cardiac arrest during spinal anesthesia is a rare event. However, its management by an unprepared team is difficult and carries poor outcomes. Hypoglycemia as the cause of sudden cardiac arrest is rarely reported. This case illustrates lifesaving procedures for sudden cardiac arrest secondary to hypoglycemia during cesarean delivery under spinal anesthesia.

Case summary

We report a case, from rural Ethiopia of sudden cardiac arrest secondary to hypoglycemia during cesarean delivery under spinal anesthesia. The case was successfully managed by a team of anesthetists and other operating teams. The mother and newborn were discharged from the hospital on the 7th postoperative day.

Conclusion

Hypoglycemia during cesarean delivery under spinal anesthesia can cause sudden cardiac arrest. Therefore, identifying patients at risk of developing hypoglycemia, monitoring the patient’s condition, and initiating prompt intervention at the first sign of cardiovascular instability is advisable. Determining serum blood glucose levels at admission to the labor ward and monitoring blood glucose levels during spinal anesthesia should be routine practices.