Paediatric anaesthesia: Overview

Pediatric Critical Care Medicine is the official journal of the Society of Critical Care Medicine​ and the World Federation of Pediatric Intensive and Critical Care Societies, and it is devoted to research and clinical care of critically ill or injured infants, children, and adolescents.

Abstract
Traditional pediatric anesthetic dosing using pharmacokinetic estimates based on age and weight is often imprecise, frequently leading to oversedation. Intraoperative electroencephalography (EEG) allows visualization of the brain's response to anesthetic agents in real time, facilitating precise titration of anesthetic drug doses optimized for the individual child. The goal of EEG-guided anesthesia management is to maintain an optimal state of hypnosis during various stages of the procedure while minimizing hemodynamic instability and other adverse effects of anesthesia. This is especially important in children with less predictable anesthetic requirements, such as children with atypical neurodevelopment, altered levels of consciousness before anesthesia, or those receiving total intravenous anesthesia, neuromuscular blockers, or a combination of anesthetic agents with different mechanisms of actions. Children with limited cardiorespiratory reserves and those undergoing high-risk procedures such as cardiopulmonary bypass also benefit from EEG guidance as they have a narrower therapeutic window for optimal anesthetic dosing. Various processed EEG (pEEG) monitors are available for intraoperative monitoring in children. These monitors display a pEEG index based on the manufacturer's algorithm, purportedly indicating the patient's hypnotic state. Due to differences in developmental neurophysiology and EEG dynamics in children, pEEG indices may not always reliably indicate the hypnotic state, especially in neonates and infants. Learning to interpret nonproprietary EEG parameters including the raw EEG, spectral-edge frequency 95% (SEF95), and density spectral array can prevent overreliance on pEEG indices. This review provides an overview of the advantages of EEG guidance during clinical anesthesia, including potential reduction in anesthetic dosage, prevention of EEG suppression, and reduction in peri-operative adverse events. We describe the use of nonproprietary EEG parameters in guiding anesthesia in children for various clinical end points including laryngoscopy, surgical incision, and maintenance of anesthesia, as well as sedation. We illustrate these principles with various case examples commonly encountered during pediatric anesthesia. Lastly, we discuss strategies to expand intraoperative EEG monitoring in children through education and training programs, as well as advocate for further research to assess clinical outcomes associated with EEG guidance to support its routine use in clinical care.

Abstract
Daily, children undergo countless investigations and interventions, which require sedation and immobilization to ensure safety and accuracy. This remains associated with a persistent risk of sedation-induced life-threatening events as children are particularly vulnerable to adverse medical events and complications. Consequently, there is an urgent need to increase the safety of pediatric sedation and anesthesia. An ideal approach involves the use of drugs with fewer intrinsic side effects. In this context, on the basis of their pharmacokinetic properties, remimazolam (RMZ) and dexmedetomidine (DEX) were evaluated for their suitability as ideal sedatives. RMZ and DEX, both of which are currently available in pediatric medicine, have shown great promise in initial publications. To date, only very limited data concerning RMZ in small children are available. RMZ is a novel, ultrashort-acting benzodiazepine that is metabolized by tissue esterase, largely independent of organ function. It has a context-sensitive half-life of approximately 10 min, with minimal accumulation even with prolonged use. Its effects can be completely reversed with flumazenil. DEX, an isomer of medetomidine, is a potent α2-receptor-agonist with multiple indications in anesthesia and intensive care medicine. It has coanalgesic potential, allows for 'arousal sedations' and has a low profile for cardiorespiratory side effects. DEX is metabolized in the liver and is predominantly excreted renally. Both drugs show potential in the prevention and treatment of delirium, with DEX having additional neuroprotective effects. DEX and RMZ possess several properties of an optimal sedative, including clinically insignificant main metabolites and a broad dosage range, indicating their potential to reduce the incidence of sedation-related life-threatening events in children. However, further clinical research is necessary to better evaluate their potential risks.

Abstract
Purpose: Whether endotracheal tube (ETT) configuration (cuffed or uncuffed) influences the occurrence of respiratory adverse events (RAEs) in patients at risk remains largely unknown. We investigated the effects of cuffed ETTs on RAE occurrence after extubation in pediatric patients with airway hypersensitivity.

Methods: Children aged < 8 years with increased airway hypersensitivity (defined as upper airway symptoms, recent upper respiratory infection within 2 weeks, or a history of asthma) who underwent general endotracheal anesthesia with inhaled agents between January 2021 and December 2022 were included. We retrospectively examined the patients' background and intraoperative anesthesia conditions by comparing the cuffed and uncuffed ETT groups. Multiple logistic regression analysis was performed to estimate the association between ETT configuration (cuffed vs. uncuffed) and the occurrence of RAEs or respiratory interventions (laryngospasm, peripheral capillary oxygen saturation < 92%, oxygen supplementation, epinephrine inhalation, or reintubation) after extubation.

Results: Cuffed ETTs were used in 163 patients and uncuffed ETTs in 143 patients. Apart from the frequency of upper airway surgery and intraoperative fluid balance, no significant differences in background characteristics were observed between the groups. RAEs after extubation were observed in 36 (22.1%) and 28 (19.6%) patients in each cuffed and uncuffed ETT groups. After adjusting for known RAE risk factors, no difference was observed in RAEs or respiratory interventions after extubation between both groups (odds ratio, 1.14; 95% confidence interval: 0.64, 2.06).

Conclusion: In pediatric patients with airway hypersensitivity, the use of cuffed ETTs did not increase the occurrence of RAEs or respiratory interventions after extubation.

Keywords: Airway hypersensitivity; Children; General anesthesia; Intubation; Risk factors.