Randomised controlled trial comparing preoperative carbohydrate loading with standard fasting in paediatric anaesthesia.

BACKGROUND: Preoperative fasting is a major cause of perioperative discomfort in paediatric anaesthesia and leads to postoperative insulin resistance, thus potentially enhancing the inflammatory response to surgery. Addressing these problems by preoperative carbohydrate intake has not been a well-defined approach in children. METHODS: We randomised 120 children scheduled for gastroscopy under general anaesthesia to either a control group of standard preoperative fasting or a study group receiving a carbohydrate beverage (PreOp™; Nutricia, Erlangen, Germany). Their stomach contents were aspirated endoscopically, and the volume and pH measured. Perioperative discomfort was evaluated using, among other parameters, an observational pain scale in ≤4-yr-olds and a VAS in >4-yr-olds. The investigators doing the endoscopies and outcome evaluations were blinded to the study group allocation. RESULTS: Compared with fasting, carbohydrate loading was associated with significantly less gastric content (P=0.01), fewer patients experiencing postoperative nausea (P=0.028), with no significant difference in postoperative vomiting. High preoperative VAS scores (>5) were recorded for only one child in the carbohydrate group vs five children in the fasting group. Bowel cleansing for simultaneous colonoscopies (n=61) made no difference to any of the intergroup findings. CONCLUSIONS: Preoperative carbohydrates can reduce nausea and gastric content, the latter being a surrogate parameter for the risk and severity of gastric aspiration into the lungs during anaesthesia. Our study adds knowledge for preoperative fasting guidelines in paediatric anaesthesia. CLINICAL TRIAL REGISTRATION: DRKS00005020.

An observational study of the macro- and micro-haemodynamic implications of epidural anaesthesia in children.

The haemodynamic implications of epidural anaesthesia in children are poorly documented. We report macro- and micro-haemodynamic data from an observational study of 25 children ranging from neonates to six-years old, who underwent surgery conducted with a specific combination of monitoring systems. We analysed 90 min of study-related monitoring after epidural catheterisation, with skin incision taking place after around 30 min. We recorded macrohaemodynamic parameters (monitored using LiDCOrapid) including heart rate, mean arterial pressure, cardiac output, stroke volume, systemic vascular resistance and stroke volume variation. Microhaemodynamic parameters (monitored using Invos™) included cerebral and peri-renal oxygenation. Based on the entire 90 min of study-related monitoring, we found significant increases in cardiac output (p = 0.009), stroke volume (p = 0.006) and stroke volume variation (p = 0.008), as well as decreases in systemic vascular resistance (p = 0.007) around 30 min after epidural blockade. There were no significant changes in heart rate, arterial pressure and cerebral or peri-renal oxygenation during these 90 min. Considering that the microhaemodynamic parameters were not affected by the macrohaemodynamic changes, we conclude that autoregulation of the brain and the kidneys was maintained in children under epidural anaesthesia.

Supraclavicular ultrasound-guided catheterization of the brachiocephalic vein in infants and children: A retrospective analysis.

OBJECTIVE/BACKGROUND: Ultrasound (US) facilitates central venous catheter (CVC) placement in children. A new supraclavicular approach using the brachiocephalic vein (BCV) for US-guided CVC placement in very small children has been recently described. In 2012, we changed our departmental standard and used the left BCV as preferred puncture site during CVC placement. In our retrospective analysis, we compared US-guided cannulation of the BCV with other puncture sites (control). DESIGN/MATERIALS AND METHODS: We performed a retrospective analysis of all CVC cannulations from October 2012 to October 2013 in our department. For cannulation of the BCV, the in-plane technique was used to guide the needle into the target vein. RESULTS: We performed CVC cannulations in 106 children (age 1-day to 18 years). In 29 patients, the weight was <4.5 kg. CVC placement was successful in all patients. The left BCV could be used in 81.1% of all cases. In a Poisson regression model of punctures regressed by age, weight or group (left BCV vs. control), age, weight or the cannulation site did not influence the number of punctures. In a logistic regression model of complications (yes vs. no) regressed by the group (left brachiocephalic vs. control) an odds ratio of 0.15 was observed (95% confidence interval 0.03-0.72, P likelihood ratio test = 0.007). CONCLUSION: US-guided puncture of the left BCV is a safe method of CVC placement in children. The use of the left BCV was associated with a high success rate in our retrospective analysis.

Dislocation rates of perineural catheters: a volunteer study.

BACKGROUND: Dislocation rates of continuous peripheral nerve block are poorly described even though this technique is frequently used in clinical practice. The present study was designed to evaluate dislocation rates over time of interscalene and femoral nerve catheters under defined experimental circumstances. Ultrasound (US) monitoring was used to detect the position of the perineural catheters. METHODS: Twenty volunteers received US-guided interscalene and femoral nerve catheters. The volunteers performed standardized physical exercises in regular intervals and the position of both catheters was examined by US confirmation of the spread of fluid. The maximal time of investigation in each volunteer was 6 h. The main outcome parameters were the overall dislocation rates and the cumulative dislocation rates at a given time point. RESULTS: We observed an overall dislocation rate of 15% (5% for interscalene catheters, 25% for femoral nerve catheters) and a significant correlation between time and rate of dislocations (r=0.99, P=0.001). US visualization of the spread of fluid was possible in all cases. CONCLUSIONS: This is the first dedicated evaluation of dislocation rates of peripheral nerve catheters (PNCs) via US investigation. Both movement and time are considerable factors for perineural catheter displacement. US is useful for the performance of PNCs and for the continuous detection of the spread of fluid relative to the nerve and adjacent anatomical structures. Translational research is required to confirm the study results in the clinical practice.

Ultrasound assessment of cranial spread during caudal blockade in children: effect of the speed of injection of local anaesthetics.

BACKGROUND: Despite caudal blockade being the most widely used regional anaesthetic procedure for infants and children undergoing subumbilical surgery, the question whether the injection velocity of the local anaesthetic itself affects its spread in the epidural space has not yet been investigated. Thus, the aim of the present study was to measure the cranial spread of caudally administered local anaesthetics in infants and children by means of real-time ultrasonography, with a special focus on comparing the effect of using two different speeds of injection. METHODS: Fifty ASA I-II infants and children, aged up to 6 yr, weighing up to 25 kg, undergoing subumbilical surgery, were enrolled in this prospective, randomized, observer-blinded study. Caudal blockade was performed under ultrasound observation using ropivacaine 1 ml kg(-1) 0.2% or 0.35% and an injection given at either 0.25 ml s(-1) or 0.5 ml s(-1), respectively. RESULTS: Ultrasound observation of the local anaesthetic flow and the extent of cranial spread was possible in all patients. All caudal blocks were considered successful, and all surgical procedures could be completed without any indications of insufficient analgesia. No statistically significant difference could be observed between the two injection speeds regarding the cranial spread of the local anaesthetic in the epidural space. CONCLUSIONS: The main finding of the present study is that the speed of injection of the local anaesthetic does not affect its cranial spread during caudal blockade in infants and children. Therefore, the prediction of the cranial spread of the local anaesthetic, depending on the injection speed, is not possible.

Ultrasound-guided cannulation of the great saphenous vein at the ankle in infants.

BACKGROUND: The establishment of peripheral venous access in infants is the most common invasive technique in paediatric anaesthesia. Venous puncture can be challenging due to the small size of vessels in this patient population. The present study was designed to investigate the practicability of ultrasound-guided vascular access to the great saphenous vein (GSV) at the level of the medial malleolus in infants ≤ 12 months. METHODS: Ninety consecutive infants ≤ 12 months undergoing elective surgery were included in this prospective study and divided into two age groups (0-6 and 7-12 months). After anaesthesia induction with sevoflurane, an ultrasound investigation of both GSVs at the level of the medial malleoli was performed. Subsequently, venous access in one GSV was established under direct ultrasound control. Anatomical ultrasound data and success rates of venous accesses were analysed. RESULTS: While not deeper relative to the skin, the GSV was significantly larger in older infants. The success rate in infants ≤ 6 months was 96%, whereas in older infants, the success rate was 100%. The overall success rate in all infants was 98%. CONCLUSIONS: Ultrasound facilitates venous puncture of the GSV in the vast majority of infants ≤ 12 months. Direct visualization via ultrasound is a promising technique for the establishment of venous access in the GSV at the level of the medial malleolus in infants.