Short anesthesia without intravenous fluid therapy in children: Results of a prospective non-interventional multicenter observational study.

BACKGROUND: The German guidelines recommend that intravenous fluid therapy should not be mandatorily performed in children with short fasting times undergoing short anesthesia, but there is a lack of clinical studies including a large number of pediatric patients. Therefore, we performed a prospective non-interventional multicenter observational study to evaluate the perioperative hemodynamic and metabolic stability of children undergoing short anesthesia without intravenous fluid therapy. AIMS: The primary aim was to assess the incidence of hypotension and the secondary aim was to assess the real preoperative fasting times, the incidence of hypoglycemia and the impact on ketone bodies and acid-base balance. METHODS: Children aged 1 month-18 years undergoing short anesthesia (<1 h) without intravenous fluid therapy were enrolled. Patient demographics, the surgical or diagnostic procedure performed, anesthesia, hemodynamic, laboratory data, and adverse events were documented using a standardized case report form. RESULTS: Four hundred and twenty seven children that were investigated at three pediatric centers from July 2021 to June 2022 (mean age 83.4 ± 58.9 months, body weight 27.9 ± 19.8 kg) were included in the analysis. The real preoperative fasting times were 14.2 ± 3.6 h for solids, 7.2 ± 3.5 h for milk and 5 ± 4.8 h for clear fluids. During the course of anesthesia, hypotension (<2.5th percentile) was detected in 3 of 427 cases (0.7%), hypoglycemia (glucose <3.0 mmol L-1) in 1 of 355 cases (0.3%), and ketosis (ketone bodies ≥0.6 mmol L-1) in 51 of 233 cases (21.9%). The occurrence of ketosis was associated with lower body weight (p <.001) and longer fasting times for solids or milk (p =.021), but not for clear fluids (p =.69). CONCLUSIONS: Our study supported the German guidelines recommendation that perioperative intravenous fluid therapy is not mandatory in children beyond the neonatal period with short pre- and postoperative fasting times undergoing short anesthesia (<1 h).

Ten-year experience of whole lung lavage in pediatric Pulmonary Alveolar Proteinosis.

BACKGROUND: Pulmonary Alveolar Proteinosis (PAP) is extremely rare and can be caused by hereditary dysfunction of the granulocyte macrophage colony-stimulating factor receptor (GM-CSF) receptor, autoantibodies against GM-CSF, or other diseases leading to alveolar macrophage (AM) dysfunction. This leads to protein accumulation in the lung and severe dyspnea and hypoxemia. Whole lung lavage (WLL) is the first line treatment strategy. METHODS: Here, we present data from more than ten years of WLL practice in pediatric PAP. WLL performed by the use of a single lumen or double lumen tube (SLT vs. DLT) were compared for technical features, procedure time, and adverse events. RESULTS: A total of n=57 procedures in six PAP patients between 3.5 and 14.3 years of age were performed. SLT based WLL in smaller children was associated with comparable rates of adverse events but with longer intervention times and postprocedural intensive care treatment when compared to DLT based procedures. DISCUSSION: Our data shows that WLL is feasible even in small children. DLT based WLL seems to be more effective, and our data supports the notion that it should be considered as early as possible in pediatric PAP. CONCLUSION: WLL lavage is possible in small PAP patients but should performed in close interdisciplinary cooperation and with age appropriate protocols.

Rebounds of sevoflurane concentration during simulated trigger-free pediatric and adult anesthesia.

BACKGROUND: In trigger-free anesthesia a volatile anesthetic concentration of 5 parts per million (ppm) should not be exceeded. According to European Malignant Hyperthermia Group (EMHG) guideline, this may be achieved by removing the vapor, changing the anesthetic breathing circuit and renewing the soda lime canister followed by flushing with O2 or air for a workstation specific time. Reduction of the fresh gas flow (FGF) or stand-by modes are known to cause rebound effects. In this study, simulated trigger-free pediatric and adult ventilation was carried out on test lungs including ventilation maneuvers commonly used in clinical practice. The goal of this study was to evaluate whether rebounds of sevoflurane develop during trigger-free anesthesia. METHODS: A Dräger® Primus® was contaminated with decreasing concentrations of sevoflurane for 120 min. Then, the machine was prepared for trigger-free anesthesia according to EMHG guideline by changing recommended parts and flushing the breathing circuits using 10 or 18 l⋅min- 1 FGF. The machine was neither switched off after preparation nor was FGF reduced. Simulated trigger-free ventilation was performed with volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) including various ventilation maneuvers like pressure support ventilation (PSV), apnea, decreased lung compliance (DLC), recruitment maneuvers, prolonged expiration and manual ventilation (MV). A high-resolution ion mobility spectrometer with gas chromatographic pre-separation was used to measure sevoflurane in the ventilation gas mixture in a 20 s interval. RESULTS: Immediately after start of simulated anesthesia, there was an initial peak of 11-18 ppm sevoflurane in all experiments. The concentration dropped below 5 ppm after 2-3 min during adult and 4-18 min during pediatric ventilation. Other rebounds of sevoflurane > 5 ppm occurred after apnea, DLC and PSV. MV resulted in a decrease of sevoflurane < 5 ppm within 1 min. CONCLUSION: This study shows that after guideline-compliant preparation for trigger-free ventilation anesthetic machines may develop rebounds of sevoflurane > 5 ppm during typical maneuvers used in clinical practice. The changes in rate and direction of internal gas flow during different ventilation modes and maneuvers are possible explanations. Therefore, manufacturers should provide machine-specific washout protocols or emphasize the use of active charcoal filters (ACF) for trigger-free anesthesia.

Incidence and characteristics of errors detected by a short team briefing in pediatric anesthesia.

BACKGROUND: In our institution, a modified WHO surgical safety checklist was implemented more than ten years ago. In retrospect, we noticed that pediatric anesthesia was underrepresented in our surgical safety checklist modification. Therefore, we added a standardized team briefing (pedSOAP-M) immediately before induction of anesthesia and hypothesized that the use of this checklist was effective to detect relevant errors with potentially harmful consequences. AIMS: The primary aim was to assess the incidence and characteristics of the detected errors, and the secondary aim was to identify factors influencing error detection. METHODS: This prospective observational study was performed between November 2020 and October 2021 in five operation rooms at the Children's Hospital of Hannover Medical School, Germany. The subcategories of the pedSOAP-M checklist were suction, oxygen, airway, pharmaceuticals, and monitoring. Demographic and procedure-related data and the briefing results were documented anonymously and undated, using a standardized case report form. RESULTS: We enrolled 1030 and analyzed 1025 patients (aged 0-18 years). Relevant errors were detected in 111 (10.8%) cases (suction 2.5%, oxygen 3.0%, airway 0.2%, pharmaceuticals 2.4%, monitoring 3.0%). In the pharmaceuticals subcategory, the most common error was entering a wrong patient weight into the perfusor syringe pumps. Experienced anesthetists detected significantly more errors than less experienced ones. CONCLUSION: The briefing tool pedSOAP-M was effective in detecting relevant errors with potentially harmful consequences. The presence of an experienced anesthetist was associated with a higher efficacy of the briefing. Particular attention should be given to entering patient weight into the anesthesia workstation and the perfusor syringe pumps.

The impact of modified fluid gelatin 4% in a balanced electrolyte solution on plasma osmolality in children-A noninterventional observational study.

BACKGROUND: Intravenous fluids for perioperative infusion therapy should be isotonic to maintain the body fluid homeostasis in children. Modified fluid gelatin 4% in a balanced electrolyte solution has a theoretical osmolarity of 284 mosmol L-1 , and a real osmolality of 264 mosmol kg H2 O-1 . Because both values are lower than those of 0.9% saline or plasma, gelatin would be expected to be hypotonic in-vitro and in-vivo. AIM: We thus hypothesized that the infusion of gelatin would be expected to decrease plasma osmolality. We performed an in-vitro experiment and an in-vivo study to evaluate the impact of gelatin on the osmolality in children. METHODS: In the in-vitro experiment, full blood samples were diluted with gelatin 4% or albumin (50 g L-1 ) from 0% (pure blood) to 100% (pure colloid), and the osmolality was measured by freezing-point depression. In the in-vivo study, blood gas analyses from children undergoing major pediatric surgery were collected before and after gelatin infusion, and the osmolality was calculated by a modified version of Zander's formula. RESULTS: In the in-vitro experiment, 65 gradually diluted blood samples from five volunteers (age 25-55 years) were analyzed. The dilution with gelatin caused no significant changes in osmolality between 0% and 100%. Compared with gelatin, the osmolality in the albumin group was significantly lower between 50% and 100% dilution (p < .05). In the in-vivo study, 221 children (age 21.4 ± 30 months) were included. After gelatin infusion, the osmolality increased significantly (mean change 4.3 ± 4.8 [95% CI 3.7-4.9] mosmol kg H2 O-1 ; p < .01) within a normal range. CONCLUSIONS: Gelatin in a balanced electrolyte solution has isotonic characteristics in-vitro and in-vivo, despite the low theoretical osmolarity, probably caused by the (unmeasured) negative charges in the gelatin molecules contributing to the plasma osmolality. For a better evaluation of the (real) tonicity of gelatin-containing solutions, we suggest to calculate the osmolality (mosmol kg H2 O-1 ) using Zander's formula. TRIAL REGISTRATION: ClinicalTrials.gov (ID: NCT02495285).

Modified fluid gelatin 4% for perioperative volume replacement in pediatric patients (GPS): Results of a European prospective noninterventional multicenter study.

INTRODUCTION: Modified fluid gelatin 4% is approved for use in children, but there is still a surprising lack of clinical studies including large numbers of pediatric patients. Therefore, we performed a European prospective noninterventional multicenter study to evaluate the use of a modified fluid gelatin 4% in saline (sal-GEL) or an acetate-containing balanced electrolyte solution (bal-GEL) in children undergoing major pediatric surgery. AIMS: The primary aim was to assess the indications and dosing of modified fluid gelatin, and the secondary aim was to assess the safety and efficacy, focusing, in particular, on routinely collected clinical parameters. METHODS: Children aged up to 12 years with ASA risk scores of I-III receiving sal-GEL or bal-GEL were followed perioperatively. Demographic data, surgical procedures performed, anesthesia, hemodynamic and laboratory data, adverse events, and adverse drug reactions were documented using a standardized case report form. RESULTS: 601 children that were investigated at 13 European pediatric centers from May 2015 to March 2020 (sal-GEL 20.1%, bal-GEL 79.9%; mean age 29.1 ± 38.6 (range 0-144) months; body weight 12.1 ± 10.5 (1.4-70) kg) were included in the analysis. The most frequent indications for GEL infusion were hemodynamic instability without bleeding (76.0%), crystalloids alone not being sufficient for hemodynamic stabilization (55.7%), replacement of preoperative deficit (26.0%), and significant bleeding (13.0%). Mean infused GEL volume was 13.0 ± 5.3 (2.4-37.5) ml kg-1 . The total dose was affected by age, with higher doses in younger patients. After gelatin infusion, mean arterial pressure increased (mean change 8.5 ± 7.3 [95% CI: 8 to 9.1] mmHg), and the hemoglobin concentrations decreased significantly (mean change -1.1 ± 1.8 [95% CI: -1.2 to -0.9] g·dL-1 ). Acid-base parameters were more stable with bal-GEL. No serious adverse drug reactions directly related to gelatin (i.e., anaphylactoid reaction, clotting disorders, and renal failure) were observed. CONCLUSION: Moderate doses up to 20 ml kg-1 of modified fluid gelatin were infused most frequently to improve hemodynamic stability in children undergoing major pediatric surgery. The acid-base balance was more stable when gelatin in a balanced electrolyte solution was used instead of saline. No serious adverse drug reactions associated with gelatin were observed.

EEG monitoring during anesthesia in children aged 0 to 18 months: amplitude-integrated EEG and age effects.

BACKGROUND: The amplitude-integrated EEG (aEEG) is a widely used monitoring tool in neonatology / pediatric intensive care. It takes into account the amplitudes, but not the frequency composition, of the EEG. Advantages of the aEEG are clear criteria for interpretation and time compression. During the first year of life, the electroencephalogram (EEG) during sedation / anesthesia changes from a low-differentiated to a differentiated EEG; higher-frequency waves develop increasingly. There are few studies on the use of aEEG during pediatric anesthesia. A systematic evaluation of the aEEG in defined EEG stages during anesthesia / sedation is not yet available. Parameters of pediatric EEGs (power, median frequency, spectral edge frequency) recorded during anesthesia and of the corresponding aEEGs (upper and lower value of the aEEG trace) should be examined for age-related changes. Furthermore, it should be examined whether the aEEG can distinguish EEG stages of sedation / anesthesia in differentiated EEGs. METHODS: In a secondary analysis of a prospective observational study EEGs and aEEGs (1-channel recordings, electrode positions on forehead) of 50 children (age: 0-18 months) were evaluated. EEG stages: A (awake), Slow EEG, E2, F0, and F1 in low-differentiated EEGs and A (awake), B0-2, C0-2, D0-2, E0-2, F0-1 in differentiated EEGs. RESULTS: Median and spectral edge frequency increased significantly with age (p < 0.001 each). In low-differentiated EEGs, the power of the Slow EEG increased significantly with age (p < 0.001). In differentiated EEGs, the power increased significantly with age in each of the EEG stages B1 to E1 (p = 0.04, or less), and the upper and lower values of the aEEG trace increased with age (p < 0.001). A discriminant analysis using the upper and lower values of the aEEG showed that EEG epochs from the stages B1 to E1 were assigned to the original EEG stage in only 19.3% of the cases. When age was added as the third variable, the rate of correct reclassifications was 28.5%. CONCLUSIONS: The aEEG was not suitable for distinguishing EEG stages above the burst suppression range. For this purpose, the frequency composition of the EEG should be taken into account.

Preparation of Dräger Atlan A350 and General Electric Healthcare Carestation 650 anesthesia workstations for malignant hyperthermia susceptible patients.

BACKGROUND: Patients at risk of malignant hyperthermia need trigger-free anesthesia. Therefore, anesthesia machines prepared for safe use in predisposed patients should be free of volatile anesthetics. The washout time depends on the composition of rubber and plastic in the anesthesia machine. Therefore, new anesthesia machines should be evaluated regarding the safe preparation for trigger-free anesthesia. This study investigates wash out procedures of volatile anesthetics for two new anesthetic workstations: Dräger Atlan A350 and General Electric Healthcare (GE) Carestation 650 and compare it with preparation using activated charcoal filters (ACF). METHODS: A Dräger Atlan and a Carestation 650 were contaminated with 4% sevoflurane for 90 min. The machines were decontaminated with method (M1): using ACF, method 2 (M2): a wash out method that included exchange of internal parts, breathing circuits and soda lime canister followed by ventilating a test lung using a preliminary protocol provided by Dräger or method 3 (M3): a universal wash out instruction of GE, method 4 (M4): M3 plus exchange of breathing system and bellows. Decontamination was followed by a simulated trigger-free ventilation. All experiments were repeated with 8% desflurane contaminated machines. Volatile anesthetics were detected with a closed gas loop high-resolution ion mobility spectrometer with gas chromatographic pre-separation attached to the bacterial filter of the breathing circuits. Primary outcome was time until < 5 ppm of volatile anesthetics and total preparation time. RESULTS: Time to < 5 ppm for the Atlan was 17 min (desflurane) and 50 min (sevoflurane), wash out continued for a total of 60 min according to protocol resulting in a total preparation time of 96-122 min. The Carestation needed 66 min (desflurane) and 24 min (sevoflurane) which could be abbreviated to 24 min (desflurane) if breathing system and bellows were changed. Total preparation time was 30-73 min. When using active charcoal filters time to < 5 ppm was 0 min for both machines, and total preparation time < 5 min. CONCLUSION: Both wash out protocols resulted in a significant reduction of trace gas concentrations. However, due to the complexity of the protocols and prolonged total preparation time, feasibility in clinical practice remains questionable. Especially when time is limited preparation of the anesthetic machines using ACF remain superior.

Quality-improvement project to reduce actual fasting times for fluids and solids before induction of anaesthesia.

BACKGROUND: Despite well-defined recommendations, prolonged fasting times for clear fluids and solids are still common before elective surgery in adults. Extended fasting times may lead to discomfort, thirst, hunger and physiological dysfunctions. Previous studies have shown that prolonged fasting times are frequently caused by patients being misinformed as well as inadequate implementation of the current guidelines by medical staff. This study aimed to explore how long elective surgery patients fast in a German secondary care hospital before and after the introduction of an educational note for patients and re-training for the medical staff. METHODS: A total of 1002 patients were enrolled in this prospective, non-randomised interventional study. According to the power calculation, in the first part of the study actual fasting times for clear fluids and solids were documented in 502 consecutive patients, verbally instructed as usual regarding the recommended fasting times for clear fluids (2 h) and solids (6 h). Subsequently, we implemented additionally to the verbal instruction a written educational note for the patients, including the recommended fasting times. Furthermore, the medical staff was re-trained regarding the fasting times using emails, newsletters and employee meetings. Thereafter, another 500 patients were included in the study. We hypothesised, that after these quality improvement procedures, actual fasting times for clear fluids and solids would be more accurate on time. RESULTS: Actual fasting times for clear fluids were in the median 11.3 (interquartile range 6.8-14.3; range 1.5-25.5) h pre-intervention, and were significantly reduced to 5.0 (3.0-7.2; 1.5-19.8) h after the intervention (median difference (95%CI) - 5.5 (- 6.0 to - 5.0) h). The actual fasting times for solids also decreased significantly, but only from 14.5 (12.1-17.2; 5.4-48.0) h to 14.0 (12.0-16.3; 5.4-32.0) h after the interventions (median difference (95%CI) - 0.52 (- 1.0 to - 0.07) h). CONCLUSIONS: The study showed considerably extended actual fasting times in elective adult surgical patients, which were significantly reduced by simple educational/training interventions. However, the actual fasting times still remained considerably longer than defined in recommended guidelines, meaning further process optimisations like obligatory fluid intake in the early morning are necessary to improve patient comfort and safety in future. TRIAL REGISTRATION: German registry of clinical studies (DRKS-ID: DRKS 00020530 , retrospectively registered).

Correlation of exhaled propofol with Narcotrend index and calculated propofol plasma levels in children undergoing surgery under total intravenous anesthesia - an observational study.

BACKGROUND: Exhaled propofol concentrations correlate with propofol concentrations in adult human blood and the brain tissue of rats, as well as with electroencephalography (EEG) based indices of anesthetic depth. The pharmacokinetics of propofol are however different in children compared to adults. The value of exhaled propofol measurements in pediatric anesthesia has not yet been investigated. Breathing system filters and breathing circuits can also interfere with the measurements. In this study, we investigated correlations between exhaled propofol (exP) concentrations and the Narkotrend Index (NI) as well as calculated propofol plasma concentrations. METHODS: A multi-capillary-column (MCC) combined with ion mobility spectrometry (IMS) was used to determine exP. Optimal positioning of breathing system filters (near-patient or patient-distant) and sample line (proximal or distal to filter) were investigated. Measurements were taken during induction (I), maintenance (M) and emergence (E) of children under total intravenous anesthesia (TIVA). Correlations between ExP concentrations and NI and predicted plasma propofol concentrations (using pediatric pharmacokinetic models Kataria and Paedfusor) were assessed using Pearson correlation and regression analysis. RESULTS: Near-patient positioning of breathing system filters led to continuously rising exP values when exP was measured proximal to the filters, and lower concentrations when exP was measured distal to the filters. The breathing system filters were therefore subsequently attached between the breathing system tubes and the inspiratory and expiratory limbs of the anesthetic machine. ExP concentrations significantly correlated with NI and propofol concentrations predicted by pharmacokinetic models during induction and maintenance of anesthesia. During emergence, exP significantly correlated with predicted propofol concentrations, but not with NI. CONCLUSION: In this study, we demonstrated that exP correlates with calculated propofol concentrations and NI during induction and maintenance in pediatric patients. However, the correlations are highly variable and there are substantial obstacles: Without patient proximal placement of filters, the breathing circuit tubing must be changed after each patient, and furthermore, during ventilation, a considerable additional loss of heat and moisture can occur. Adhesion of propofol to plastic parts (endotracheal tube, breathing circle) may especially be problematic during emergence. TRIAL REGISTRATION: The study was registered in the German registry of clinical studies (DRKS-ID:  DRKS00015795 ).

Prevention of postoperative bleeding after complex pediatric cardiac surgery by early administration of fibrinogen, prothrombin complex and platelets: a prospective observational study.

BACKGROUND: Postoperative bleeding is a major problem in children undergoing complex pediatric cardiac surgery. The primary aim of this prospective observational study was to evaluate the effect of an institutional approach consisting of early preventive fibrinogen, prothrombin complex and platelets administration on coagulation parameters and postoperative bleeding in children. The secondary aim was to study the rate of re-intervention and postoperative transfusion, the occurrence of thrombosis, length of mechanical ventilation, ICU stay and mortality. METHODS: In fifty children (age 0-6 years) with one or more predefined risk factors for bleeding after cardiopulmonary bypass (CPB), thrombelastography (TEG) and standard coagulation parameters were measured at baseline (T1), after CPB and reversal of heparin (T2), at sternal closure (T3) and after 12 h in the ICU (T4). Clinical bleeding was evaluated by the surgeon at T2 and T3 using a numeric rating scale (NRS, 0-10). RESULTS: After CPB and early administration of fibrinogen, prothrombin complex and platelets, the clinical bleeding evaluation score decreased from a mean value of 6.2 ± 1.9 (NRS) at T2 to a mean value of 2.1 ± 0.8 at T3 (NRS; P <  0.001). Reaction time (R), kinetic time (K), maximum amplitude (MA) and maximum amplitude of fibrinogen (MA-fib) improved significantly (P <  0.001 for all), and MA-fib correlated significantly with the clinical bleeding evaluation (r = 0.70, P <  0.001). The administered total amount of fibrinogen (mg kg- 1) correlated significantly with weight (r = - 0.42, P = 0.002), priming volume as percentage of estimated blood volume (r = 0.30, P = 0.034), minimum CPB temperature (r = - 0.30, P = 0.033) and the change in clinical bleeding evaluation from T2 to T3 (r = 0.71, P <  0.001). The incidence of postoperative bleeding (> 10% of estimated blood volume) was 8%. No child required a surgical re-intervention, and no cases of thrombosis were observed. Hospital mortality was 0%. CONCLUSION: In this observational study of children with an increased risk of bleeding after CPB, an early preventive therapy with fibrinogen, prothrombin complex and platelets guided by clinical bleeding evaluation and TEG reduced bleeding and improved TEG and standard coagulation parameters significantly, with no occurrence of thrombosis or need for re-operation. TRIAL REGISTRATION: German Clinical Trials Register DRKS00018109 (retrospectively registered 27th August 2019).

Ultrasound assessment of gastric emptying time after intake of clear fluids in children scheduled for general anesthesia-A prospective observational study.

BACKGROUND: While many clinics have changed their local regimen toward a more liberal policy regarding clear fluid fasting for general anesthesia, there is a lack of studies evaluating gastric emptying time in a clinical setting. AIMS: Based on this and before implementation of a more liberal preoperative clear fluid fasting policy for children, we studied gastric emptying time of clear fluids in children and hypothesized that the mean gastric emptying time would be 1 hour. METHODS: Between March and December 2019, children scheduled for general anesthesia at our University Children's Hospital were enrolled in this prospective observational study. After overnight fasting, gastric emptying was examined by sonographic measurements of the gastric antral area before and 5, 15, 30, 45, and 60 minutes after intake of water or fruit juice. RESULTS: Twenty-six children were enrolled in this study, and 24 aged 11 (range 4-17) years were included for statistical analysis. The median ingested fluid volume was 4.7 (range 1.8-11.8) mL kg-1 . The gastric antral area of the children initially increased and subsequently decreased after intake of clear fluids and correlated significantly with fasting time (r = -0.55, P < .0001). After 1 hour, the gastric antral area had returned to the baseline level in 20 children but not in four children with a fluid intake >5 mL kg-1 . There was no difference in the gastric antral area between water and fruit juice. Using a linear regression model, the calculated mean gastric emptying time of clear fluids was 52 minutes. CONCLUSION: This study showed that the gastric emptying time of children after intake up to 5 mL kg-1 clear fluids was <1 hour in a clinical setting. These results support the more liberal fasting regimen favoring a 1-hour fasting time and suggest 5 mL kg-1 as an upper limit for clear fluids (eg, water, sugared water or tea or diluted fruit juice) from 2 hours to 1 hour before induction of anesthesia in children.

Stability of 0.5% Glucose-Containing Balanced Electrolyte Solutions for Patients on Ketogenic Diets: A Laboratory Study.

PURPOSE: Ketogenic diets (KDs) are used to treat epilepsies resistant to pharmacotherapy or some inborn errors of metabolism. For prolonged anesthesia, use of balanced electrolyte solutions (BESs) supplemented with 0.5% glucose has been advocated to maintain ketosis while preventing hypoglycemia. Unfortunately, there is no BES containing 0.5% glucose available from pharmacies. In a laboratory study, we investigated the physical and chemical stability of different BES mixtures containing 0.5% glucose. METHODS: In total, six approaches were chosen to create a BES with 0.5% glucose: three different glucose-free BESs were supplemented with glucose. Additionally, commercially available BES containing 1% glucose was diluted with three different glucose-free BESs to obtain a solution containing 0.5% glucose. Turbidity, pH, electrical conductivity, and macroscopic appearance of these solutions were measured immediately, at 24 hours, and after 7 days, and were compared with the original BES. RESULTS: Turbidity, pH, and electrical conductivity, as well as macroscopic appearance did not exceed the changes of the controls. CONCLUSIONS: No signs of incompatibility reactions could be observed in a 1-week time period. Our study supports the stability of the examined BES containing 0.5% glucose for prolonged anesthesia in patients on KD. Clinical studies are needed to evaluate if BES containing 0.5% glucose is superior in patients on KDs.

Effect of etomidate on systemic and regional cerebral perfusion in neonates and infants with congenital heart disease: A prospective observational study.

BACKGROUND: Neonates and infants with congenital heart disease undergoing general anesthesia have an increased risk for critical cardiovascular events. Etomidate produces very minimal changes in hemodynamic parameters in older children with congenital heart disease. There is a lack of studies evaluating the effect of etomidate on systemic and regional cerebral perfusion in neonates and infants with congenital heart disease. AIM: The aim of this prospective observational study was to evaluate the effect of etomidate on systemic and regional cerebral perfusion in neonates and infants with congenital heart disease. METHODS: In fifty infants aged 0-11 months (24% neonates n = 12) with congenital heart disease, mean arterial blood pressure, cardiac index using electrical cardiometry, and regional cerebral oxygen saturation using near-infrared spectroscopy were measured at baseline and 1, 3, 5, and 10 minutes after induction by 0.4 mg kg-1 etomidate. Hypotension was defined as a mean arterial blood pressure under 35 mm Hg and cerebral desaturation as a regional cerebral oxygen saturation of less than 80% of baseline. RESULTS: Mean arterial blood pressure, cardiac index, and regional cerebral oxygen saturation remained stable above the predefined limits. Mean arterial blood pressure decreased slightly within a physiological range after 3 minutes (P = .005, 95% CI:-5.9 to -1.0). No significant change in cardiac index could be observed. CONCLUSION: Etomidate 0.4mg kg-1 does not impair systemic or regional cerebral perfusion in neonates or infants with congenital heart disease.

Systemic and regional cerebral perfusion in small infants undergoing minor lower abdominal surgery under awake caudal anaesthesia: An observational study.

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 ±â€Š13 (range 20 to 71) min. The infants were discharged to the neonatal ward after the end of surgery, and milk was fed 22 ±â€Š15 (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).

Preparation of anaesthesia workstation for trigger-free anaesthesia: An observational laboratory study.

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 (Dräger) 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 (<5 ppm): 0.5 l min fresh gas flow was required in sevoflurane experiments. While activated charcoal filters in the sevoflurane tests passed the functional test after 24 h, activated charcoal filters in the desflurane tests failed. CONCLUSION: Activated charcoal filters meet the requirements for trigger-free low flow (1 l min) ventilation over 24 h. Minimal flow (0.5 l min) ventilation may be possible for sevoflurane contaminated machines.

Ultrasound assessment of gastric emptying time in preterm infants: A prospective observational study.

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 ±â€ŠSD (range) age of 35 ±â€Š2 (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 ±â€Š16 (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 < 0.0001). At FT3 [199 ±â€Š16 (175 to 225) min], GAA was 0.57 (0.42 to 0.91) cm and showed no difference compared with FT0. Using a linear regression model, the calculated mean gastric emptying time was 218 min. CONCLUSION: The study shows that the mean gastric emptying time after enteral feeding with breast milk and formula milk is less than 4 h in preterm infants. These results support our current national fasting regimen of 4 h for any milk composition in infants before anaesthesia. TRIAL REGISTRATION: German registry of clinical studies (DRKS-ID: DRKS 00013893).

Impact of Capnoperitoneum on Renal Perfusion and Urine Production in Infant and Adolescent Pigs: Crystalloid versus Colloid Fluid Resuscitation.

BACKGROUND: Infants are likely to develop anuria during laparoscopy which is uncommon in older patients. The reason for this susceptibility remains unknown. We compared the impact of CO2 pneumoperitoneum on renal perfusion and urine production in piglets compared with adolescent pigs. We furthermore investigated the effects of different resuscitation strategies. MATERIALS AND METHODS: Male piglets (n = 21) were divided into four groups: (a) infant controls (n = 5), (b) infants with crystalloid restitution (n = 6), (c) infants with colloidal restitution (n = 5), and (d) adolescents with crystalloid restitution (n = 5). Animals were ventilated, the central vessels and ureters were cannulated, and the animals were subjected to a 3-hour, 10 mm Hg CO2 pneumoperitoneum followed by 2-hour resuscitation. Renal perfusion was assessed by fluorescent microspheres and the rate of urine flow was measured. RESULTS: Urine production significantly decreased after insufflation only in the infant crystalloid and adolescent group, but not in controls or infants treated with colloids. In the infant crystalloid group, urine production remained at levels below 20% of baseline throughout the experiment. In this group, the renal perfusion dropped significantly after the beginning of the capnoperitoneum and remained significantly reduced throughout the experiment. CONCLUSION: Our data indicates that capnoperitoneum impairs renal perfusion and urine production in infants. In moderate-pressure capnoperitoneum, this effect cannot be compensated by application of crystalloids but with colloids.

Ultrasound assessment of gastric emptying time after a standardised light breakfast in healthy children: A prospective observational study.

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 ±â€ŠSD (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 ±â€Š120 (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 < 0.05). Correlation between GAA in RLP and fasting time was significant (r = -0.62, P < 0.0001). Using a linear regression model, the calculated mean gastric emptying time after the standardised light breakfast was 211 min for GAA = 3.06 cm. CONCLUSION: The study showed a mean gastric emptying time of less than 4 h after a standardised light breakfast in children. These results encourage our current clinical practice and support the efforts towards a more liberal fasting regimen for light meals in paediatric anaesthesia. TRIAL REGISTRATION: German Registry of Clinical Studies (DRKS-ID: DRKS 00013893).