Current paediatric anaesthetic fasting guidelines have recommended conservative fasting regimes for many years and have not altered much in the last decades. Recent publications have employed more liberal fasting regimes with no evidence of increased aspiration or regurgitation rates. In this first solely paediatric European Society of Anaesthesiology and Intensive Care (ESAIC) pre-operative fasting guideline, we aim to present aggregated and evidence-based summary recommendations to assist clinicians, healthcare providers, patients and parents. We identified six main topics for the literature search: studies comparing liberal with conservative regimens; impact of food composition; impact of comorbidity; the use of gastric ultrasound as a clinical tool; validation of gastric ultrasound for gastric content and gastric emptying studies; and early postoperative feeding. The literature search was performed by a professional librarian in collaboration with the ESAIC task force. Recommendations for reducing clear fluid fasting to 1 h, reducing breast milk fasting to 3 h, and allowing early postoperative feeding were the main results, with GRADE 1C or 1B evidence. The available evidence suggests that gastric ultrasound may be useful for clinical decision-making, and that allowing a ‘light breakfast’ may be well tolerated if the intake is well controlled. More research is needed in these areas as well as evaluation of how specific patient or treatment-related factors influence gastric emptying.

Regulation of fluid balance is pivotal during surgery and anesthesia and affects patient morbidity, mortality, and hospital length of stay. Retention of sodium and water is known to occur during surgery but the mechanisms are poorly defined. In this study, we explore how the volatile anesthetic sevoflurane influences renal function by affecting renal sympathetic nerve activity (RSNA). Our results demonstrate that sevoflurane induces renal sodium and water retention during pediatric anesthesia in association with elevated plasma concentration of renin but not arginine–vasopressin. The mechanisms are further explored in conscious and anesthetized ewes where we show that RSNA is increased by sevoflurane compared with when conscious. This is accompanied by renal sodium and water retention and decreased renal blood flow (RBF). Finally, we demonstrate that renal denervation normalizes renal excretory function and improves RBF during sevoflurane anesthesia in sheep. Taken together, this study describes a novel role of the renal sympathetic nerves in regulating renal function and blood flow during sevoflurane anesthesia.

Preoperative fasting regimens designed to minimise the risk of pulmonary aspiration have undergone significant changes, but unequivocal evidence of the safety of reducing clear fluid fasting has been lacking. We compared the risk of pulmonary aspiration in children using three different recommendations for clear fluid fasting. In this prospective multicentre cohort study, centres with >1000 paediatric anaesthesia cases per year were eligible. Regurgitation events, whether they were transient or led to consequences affecting postoperative care, were reported in detail. All centres also reported the number of anaesthetised children per year and which preoperative fasting regimen they used. The 31 participating centres contributed a total of 306 900 anaesthetic procedures. The incidence of confirmed pulmonary aspiration was 1.18:10 000 in the sip-til-send group, 0.96:10 000 in the ≥1 h group, and 1.83:10 000 in the control group. There was no mortality as a result of aspiration. The 95% confidence intervals of the differences in confirmed pulmonary aspiration between the control group and the ≥1 h clear fluid fasting and the sip-til-send group were -0.344 to 3.76 and -1.48 to 3.63, respectively. Both sip-til-send and ≥1 h clear fluid fasting were statistically noninferior to ≥2 h clear fluid fasting regarding the incidence of confirmed aspiration, transient regurgitation, and regurgitation leading to escalation of care or intensive care. The study provides evidence for the safety of reducing preoperative fasting time for clear fluids in children aged <16 yr from 2 h to ≤1 h.

Background: Preoxygenation efficacy with high‐flow nasal cannula (HFNC) in obese patients is not clearly established. The primary aim of this study was to compare heated, humidified, high‐flow nasal cannula with face mask for preoxygenation in this population.Methods: We conducted a single‐centre, randomised, controlled trial. Forty subjects with BMI ≥ 35 kg m⁻² were randomly assigned to receive 5.0 min of preoxygenation with face mask and 7 cm H₂O of PEEP (PEEP group) or HFNC at 70 L min⁻¹ (HF group). Following induction, bag‐mask ventilation continued until laryngoscopy, whereas HFNC was maintained before and during intubation. The primary outcomes were end‐tidal fraction of oxygen (EtO₂) at 2.5 and 5.0 min duration of preoxygenation. Secondary outcomes included PaO₂ and PaCO₂ at 2.5 and 5.0 min of preoxygenation and at intubation.Results: Mean (±SD) EtO₂ was 0.89 (±0.04) versus 0.90 (±0.05) after 2.5 min (95% CI for mean difference −0.02, 0.04) and 0.93 (±0.02) versus 0.91 (±0.02) after 5.0 min of preoxygenation (95% CI for mean difference −0.03, −0.002) in the PEEP (n = 18) and HF group (n = 20), respectively. All subjects reached an EtO₂ ≥ 0.85 at 5.0 min. There were no differences in mean PaO₂ or PaCO₂ during preoxygenation. Subjects in the HF group had a mean (±SD) apnoea time of 199 (±38) s, but no desaturation (SpO₂ < 100%) occurred.Conclusions: Face mask with PEEP was superior to HFNC for preoxygenation in obese subjects. HFNC provided adequate preoxygenation quality in all subjects and may be considered as an alternative to face mask in selected patients.Trial registration: #ISRCTN37375068 (www.isrctn.com).

This review discusses the evolution of preoperative fasting guidelines and examines the incidence of pulmonary aspiration of gastric contents and suggested treatments. Nine guidelines developed by professional societies and published in peer-reviewed journals since 1994 were identified. The recommendations on preoperative fasting for various categories have undergone only small adaptations in the following three decades in pediatric anesthesia. We found twelve published studies of the incidence of pulmonary aspiration, which ranges from 0.6 to 12 in 10,000 anesthetics in children. However, this variation reflects differences in the definition of aspiration as well as differences in study design. The main risk factors identified are emergency surgery, ASA physical status, and patient age. Several additional risk factors have been suggested, including non-compliance to fasting guidelines. The duration of clear fluid fasting is not associated with an increased risk of pulmonary aspiration which may be reflected in future guideline updates in pediatric anesthesia.