Search

BACKGROUND Trigger-free anaesthesia is required for patients who are susceptible to malignant hyperthermia. Therefore, all trace of volatile anaesthetics should be removed from anaesthetic machines before induction of anaesthesia. Because the washout procedure is time consuming, activated charcoal filters have been introduced, but never tested under minimal flow conditions. OBJECTIVE To investigate performance of activated charcoal filters during long duration (24 h) simulated ventilation. DESIGN A bench study. SETTING A Primus anaesthesia machine (Drager) was contaminated with either 4% sevoflurane or 8% desflurane by ventilating a test lung for 90 min. The machine was briefly flushed according to manufacturer instructions, activated charcoal filters were inserted and a test lung was ventilated in a 24 h test. Trace gas concentrations were measured using a closed gas loop high-resolution ion mobility spectrometer with gas chromatographic preseparation. During the experiment reduced fresh gas flows were tested. At the end of each experiment the activated charcoal filters were removed and the machine was set to standby for 10 min to test for residual contamination within the circuit. The activated charcoal filters were reconnected into the circuit to test their ability to continue removing volatile anaesthetics (functional test) from the gas. Control experiments were conducted without activated charcoal filters. MAIN OUTCOME MEASURES Absolute concentrations of desflurane and sevoflurane. RESULTS The concentration of volatile anaesthetics dropped to less than 5 ppm (parts per million) following insertion of activated charcoal filters. In the desflurane experiments at least 1 l min FGF was needed to keep the concentration below an acceptable level (

OBJECTIVES Current guidelines recommend 6 h of fasting for solids before anaesthesia. However, prolonged fasting may lead to discomfort, hunger, thirst, misbehaviour and lipolysis. To prevent this, a more liberal fasting regimen has been empirically implemented in our children's hospital, allowing a shorter fasting time of 4 h for a standardised light breakfast. AIM The aim of this study was to determine the gastric emptying time after a standardised light breakfast in healthy children. DESIGN A prospective observational noninterventional study. METHODS After fasting overnight, the children had a standardised light breakfast. Before and afterwards, ultrasound examinations of the gastric antrum were performed hourly to determine the gastric antral area (GAA), which is a surrogate parameter for gastric volume in children in the right lateral position (RLP). Demographic data and fasting times are presented as mean ± SD (range) and GAA as median (interquartile range). RESULTS Twenty-two children aged 7.8 (2.5 to 13.6) years volunteered for this study. After fasting overnight [735 ± 120 (467 to 930) min], the initial GAA was 3.06 (2.35 to 4.03) cm in RLP. After the light breakfast, GAA in RLP initially increased and decreased subsequently. After 4 h, GAA in RLP was lower than the initial value (median of differences -0.54, 95% confidence interval -1.00 to -0.07, P

Background Infants undergoing general anaesthesia have an increased risk of severe respiratory and cardiovascular critical events. Awake caudal anaesthesia is an alternative for small infants undergoing minor lower abdominal surgery. While clinical experience has shown stable intra-operative haemodynamic conditions, there are no studies evaluating systemic and regional cerebral perfusion during such a procedure. Objectives The purpose of this study was to evaluate the effects of awake caudal anaesthesia on systemic and regional cerebral perfusion in small infants. Design A prospective observational cohort study. Setting Clinic of Anaesthesiology, University Children's Hospital, between November 2017 and June 2018. Patients Twenty small infants (postmenstrual age 36 to 54 weeks, weight 1800 to 5700 g) scheduled for lower abdominal surgery under awake caudal anaesthesia were enrolled in this study. Intervention Standard monitoring was expanded to include cardiac index using electrical velocimetry and regional cerebral oxygen saturation using near infrared spectroscopy. The caudal block was performed with 0.3% ropivacaine 1 ml kg Hypotension was defined as mean arterial blood pressure (BP) less than 35 mmHg and regional cerebral desaturation as regional cerebral oxygen saturation less than 80% of baseline. Main outcomes Mean arterial BP, cardiac index and regional cerebral oxygen saturation parameters under awake caudal anaesthesia. Results Mean arterial BP, cardiac index and regional cerebral oxygen saturation remained above the predefined lower limits. No episodes of hypotension or regional cerebral desaturation were observed. Operation time was 35 ± 13 (range 20 to 71) min. The infants were discharged to the neonatal ward after the end of surgery, and milk was fed 22 ± 15 (range 6 to 55) min thereafter. Five preterm infants experienced self-limiting episodes of apnoea intra-operatively. Conclusion The current study shows that awake caudal anaesthesia does not impair systemic and regional cerebral perfusion in small infants. Trial registration German registry of clinical studies (DRKS-ID: 800015742).

Background Volatile anaesthetics are a potential hazard during occupational exposure, pregnancy or in individuals with existing disposition to malignant hyperthermia. Anaesthetic waste gas concentration in postanaesthesia care units (PACU) has rarely been investigated. Objective(s) The current study aims to assess concentrations of volatile anaesthetics in relation to room size, number of patients and ventilator settings in different PACUs. Design A prospective observational study. Setting Two different PACUs of the Hannover Medical School (Hannover, Germany) were evaluated in this study. The rooms differed in dimensions, patient numbers and room ventilation settings. Patients During the observation period, sevoflurane anaesthesia was performed in 65 of 140 patients monitored in postanaesthesia unit one and in 42 of 70 patients monitored in postanaesthesia unit two. Main outcome measures Absolute trace gas room concentrations of sevoflurane measured with a compact, closed gas loop high-resolution ion mobility spectrometer. Results Traces of sevoflurane could be detected in 805 out of 970 samples. Maximum concentrations were 0.96 ± 0.20 ppm in postanaesthesia unit one, 0.82 ± 0.07 ppm in postanaesthesia unit two. Median concentration was 0.12 (0.34) ppm in postanaesthesia unit one and 0.11 (0.28) ppm in postanaesthesia unit two. Conclusion Low trace amounts of sevoflurane were detected in both PACUs equipped with controlled air exchange systems. Occupational exposure limits were not exceeded.

BACKGROUND In paediatric anaesthesia, pre-operative fasting should be short to prevent discomfort, hunger, thirst and metabolic disorders. Current European guidelines recommend pre-operative fasting times of 4 h for breast milk and 6 h for formula milk in infants, whereas some national guidelines allow both until 4 h before anaesthesia. OBJECTIVE We evaluated the gastric emptying times of preterm infants after breast milk and formula milk, hypothesising that the mean gastric emptying time would be less than 4 h. DESIGN A prospective, observational, noninterventional cohort study. SETTING Neonatal ICU of a university hospital from August to September 2017. PATIENTS Twenty-two infants with a postmenstrual mean ± SD (range) age of 35 ± 2 (32 to 40) weeks were included. Based on their prescription plan, 10 infants received breast milk and 12 received formula milk with a total volume of 50 ± 16 (24 to 70) ml. INTERVENTIONS Gastric emptying was examined by sonographic measurements of the gastric antral area (GAA) before (FT0) and hourly after breast milk or formula milk feeding (FT1 to FT3). MAIN OUTCOME MEASURES Estimated gastric emptying time after enteral feeding with breast milk and formula milk in preterm infants. RESULTS The GAA of the preterm infants initially increased and subsequently decreased after feeding. GAA correlated significantly with fasting time (r = -0.53, P

BACKGROUND In contrast to preoperative fasting guidelines in paediatric anaesthesia, actual fasting times are often too long. OBJECTIVE The objective of this study was to evaluate the effect of preoperative fasting on glucose concentration, ketone bodies and acid-base balance in children. DESIGN A prospective, noninterventional, clinical observational study. SETTING A single-centre trial, study period from June 2014 to November 2014. PATIENTS One hundred children aged 0 to 36 months scheduled for elective paediatric surgery. MAIN OUTCOME MEASURES Patient demographics, fasting times, haemodynamic data, glucose and ketone body concentrations, and acid-base parameters after induction of anaesthesia were documented using a standardised case report form. RESULTS Mean fasting period was 7.8 ± 4.5 (3.5 to 20) h, and deviation from guideline (ΔGL) was 3.3 ± 3.2 (-2 to 14) h. Linear regression showed a significant correlation between fasting times and ketone bodies, anion gap, base excess, osmolality as well as bicarbonate (for each, P < 0.05), but not glucose or lactate. In children with ΔGL more than 2 h (54%), ketone bodies, osmolality and anion gap were significantly higher and base excess significantly lower than children with ΔGL less than 2 h (for each, P < 0.05). CONCLUSION After prolonged preoperative fasting, children younger than 36 months can present with ketoacidosis and (low) normal blood glucose concentrations. Actual fasting times should be optimised according to existing guidelines. In small infants, deviations from fasting guidelines should be as short as possible and not longer than 2 h.