2025/11/07 by Renata K. Carvalho, Gustavo Moreira, Sérgio Tufik +1 · 1 voice
Neuroscience · #Circadian rhythm and melatonin #Anesthesia and Neurotoxicity Research #Sleep and Wakefulness Research
paper · pdf · doi:10.1111/anae.70065
openalex publication_date 2025/11/07 · openalex created_date 2025/11/08 · openalex updated_date 2026/08/01
We read with interest the article by Meewisse et al. [1], whose findings make a significant contribution to paediatric medicine by strengthening the understanding of anaesthetic effects on childhood sleep across different contexts. We commend the authors for their detailed prospective design and the use of validated questionnaires and diaries, particularly for the assessment of the first night following anaesthesia, which is investigated rarely in this population. The contrasting results with previous studies underscore the need for further in-depth research on this topic. From a pharmacodynamic perspective, anaesthetic drugs act on pathways also involved in the regulation of sleep, particularly neurotransmitter systems such as gamma aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA), although they differ in the physiological determinants that modulate them [2]. While the sleep–wake state is governed by both homeostatic and circadian mechanisms, the effects of anaesthesia depend primarily on the dose and the drug used. Evidence in adults and children suggests that drugs such as propofol modulate the activity of brain nuclei responsible for maintaining restorative rest. The impacts may vary according to the timing of administration and the duration of exposure [3]. Experimental research further indicates that anaesthesia can alter the expression of genes regulating circadian rhythms within the suprachiasmatic nuclei, including PER, CRY, CLOCK, and BMAL1 [2], potentially interfering with melatonin secretion and sleep architecture. It is noteworthy that, although the midpoint of sleep was not altered and the typical circadian phase advances seen in adults [4] were not observed, several peculiarities merit attention. The surgical group tended to fall asleep slightly later than the control group, suggesting that even subtle alterations in the sleep–wake cycle can be detected. The phase delay observed in male children is striking, an effect that likely results from multiple interacting factors, including hormonal and physiological differences related to circadian maturation [5]. This finding warrants additional investigation in future analyses. To advance this field, we consider it important that future investigations include a control group of participants not undergoing any hospital procedures to provide a clear-cut reference for the isolated impact of anaesthesia and surgery on paediatric sleep quality. Similarly, exploring different timings of anaesthetic administration, combined with objective measurement of circadian markers such as salivary melatonin, could better elucidate the underlying mechanisms. These measures, in addition to being simple and validated [5], are feasible within the peri-operative setting for toddlers, as they do not require invasive monitoring. Given the complexity of the effect of general anaesthesia on sleep, understanding these interactions during childhood may help clarify discrepancies between clinical studies and guide the development of more appropriate protocols, particularly for prolonged procedures. Integrating chronobiology into the study of paediatric anaesthesia represents a promising avenue for designing individualised strategies.