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).

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.

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).

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.

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.

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.

Impact of clear fluid fasting on pulmonary aspiration in children undergoing general anesthesia: Results of the German prospective multicenter observational (NiKs) study

BACKGROUND

A preliminary national audit of real fasting times including 3324 children showed that the fasting times for clear fluids and light meals were frequently shorter than recommended in current guidelines, but the sample size was too small for subgroup analyses.

AIMS

Therefore, the primary aim of this extended study with more participating centers and a larger sample size was to determine whether shortened fasting times for clear fluids or light meals have an impact on the incidence of regurgitation or pulmonary aspiration during general anesthesia in children. The secondary aim was to evaluate the impact of age, emergent status, ASA classification, induction method, airway management or surgical procedure.

METHODS

After the Ethics Committee's approval, at least more than 10 000 children in total were planned to be enrolled for this analysis. Patient demographics, real fasting times, anesthetic and surgical procedures, and occurrence of target adverse events defined as regurgitation or pulmonary aspiration were documented using a standardized case report form.

RESULTS

At fifteen pediatric centers, 12 093 children scheduled for surgery or interventional procedures were included between October 2018 and December 2019. Fasting times were shorter than recommended in current guidelines for large meals in 2.5%, for light meals in 22.4%, for formula milk in 5.3%, for breastmilk in 10.9%, and for clear fluids in 39.2%. Thirty-one cases (0.26%) of regurgitation, ten cases (0.08%) of suspected pulmonary aspiration, and four cases (0.03%) of confirmed pulmonary aspiration were reported, and all of them recovered quickly without any consequences. Fasting times for clear fluids shortened from 2 hours to 1 hour did not affect the incidence of adverse events (upper limit 95% CI 0.08%). The sample size of the cohort with fasting times for light meals shorter than 6 hours was too small for a subgroup analysis. An age between one and 3 years (odds ratio 2.7,95% CI 1.3 to 5.8%; P < .01) and emergent procedures (odds ratio 2.8,95% CI 1.4 to 5.7;P < .01) increased the incidence of adverse events, whereas ASA classification, induction method, or surgical procedure had no influence. The clear fluid fasting times were shortest under 6/4/0 as compared to 6/4/1 and 6/4/2 fasting regimens, all with an incidence of 0.3% for adverse events.

CONCLUSION

This study shows that a clear fluid fasting time shortened from 2 hours to 1 hour does not affect the incidence of regurgitation or pulmonary aspiration, that an age between one and 3 years and emergent status increase the incidence of regurgitation or pulmonary aspiration, and that pulmonary aspiration followed by postoperative respiratory distress is rare and usually shows a quick recovery.

[Perioperative Infusion Therapy in Children]

The composition and type of intravenous fluids during paediatric anaesthesia have been subjects of debates for decades. Errors in perioperative infusion therapy in children may lead to serious complications and a negative outcome. Therefore, in this review historical and recent developments and recommendations for perioperative fluid management in children are presented, based on physiology and focused on safety and efficacy. Recent studies showed that optimized preoperative fasting times and liberal clear fluid intake until 1 h improve patient comfort and metabolic and haemodynamic condition after induction of anaesthesia. Physiologically composed balanced isotonic electrolyte solutions are safer than hypotonic electrolyte solutions or saline 0.9% to protect young children against the risks of hyponatraemia and hyperchloremic acidosis. For intraoperative maintenance infusion, addition of 1 - 2% glucose is sufficient to avoid hypoglycaemia, lipolysis or hyperglycaemia. Modified fluid gelatine or hydroxyethyl starch in balanced electrolyte solution can safely be used to quickly normalize blood volume in case of perioperative circulatory instability and blood loss. In conclusion, physiologically composed infusion solutions are beneficial for maintaining homeostasis, shifting the status more towards the normal range in children with pre-existing imbalances and have a wide safety margin in case of accidental hyperinfusion.

Real fasting times and incidence of pulmonary aspiration in children: Results of a German prospective multicenter observational study

BACKGROUND

Prolonged fasting before anesthesia is still common in children. Shortened fasting times may improve the metabolic and hemodynamic condition during induction of anesthesia and the perioperative experience for parents and children and simplify perioperative management. As a consequence, some centers in Germany have reduced fasting requirements, but the national guidelines are still unchanged.

AIMS

This prospective multicenter observational study was initiated by the Scientific Working Group for Pediatric Anesthesia of the German Society of Anesthesiology and Intensive Care Medicine to evaluate real fasting times and the incidence of pulmonary aspiration before a possible revision of national fasting guidelines.

METHODS

After the Ethics Committee's approval, at least 3000 children were planned to be enrolled for this analysis. Patient demographics, real fasting times, anesthetic and surgical procedures and occurrence of regurgitation or pulmonary aspiration were documented using a standardized case report form. Results were presented as median [interquartile range] (range) or incidence (percentage).

RESULTS

At ten pediatric centers, 3324 children were included between October 2018 and May 2019. The real fasting times for large meals were 14 [12.2-15.6] (0.5-24) hours, for light meals 9 [5.6-13.3] (0.25-28.3) hours, for formula milk 5.8 [4.5-7.4] (0.9-24) hours, for breast milk 4.8 [4.2-6.3] (1.3-25.3) hours and for clear fluids 2.7 [1.5-6] (0.03-22.8) hours. Prolonged fasting (deviation from guideline >2 hours) was reported for large meals in 88.3%, for light meals in 54.7%, for formula milk in 44.4%, for breast milk in 25.8% and for clear fluids in 34.2%. Eleven cases (0.33%) of regurgitation, four cases (0.12%) of suspected pulmonary aspiration and two cases (0.06%) of confirmed pulmonary aspiration were reported; all of them could be extubated after the end of the procedure and recovered without any incidents.

CONCLUSION

This study shows that prolonged fasting is still common in pediatric anesthesia in Germany that pulmonary aspiration with postoperative respiratory distress is rare and that improvements to current local fasting regimens and national fasting guidelines are urgently needed.

Intranasal Analgesia and Sedation in Pediatric Emergency Care-A Prospective Observational Study on the Implementation of an Institutional Protocol in a Tertiary Children's Hospital

OBJECTIVES

Children presenting with acute traumatic pain or in need of therapeutic or diagnostic procedures require rapid and effective analgesia and/or sedation. Intranasal administration (INA) promises to be a reliable, minimally invasive delivery route. However, INA is still underused in Germany. We hence developed a protocol for acute pain therapy (APT) and urgent analgesia and/or sedation (UAS). Our aim was to evaluate the effectiveness and safety of our protocol.

METHODS

We performed a prospective observational study in a tertiary children's hospital in Germany. Pediatric patients aged 0 to 17 years requiring APT or UAS were included. Fentanyl, s-ketamine, midazolam, or combinations were delivered according to protocol. Primary outcome variables included quality of analgesia and/or sedation as measured on age-appropriate scales and time to onset of drug action. Secondary outcomes were adverse events and serious adverse events.

RESULTS

One hundred pediatric patients aged 0.3 to 16 years were enrolled, 34 for APT and 66 for UAS. The median time onset of drug action was 5 minutes (ranging from 2 to 15 minutes). Fentanyl was most frequently used for APT (n = 19). Pain scores decreased by a median of 4 points (range, 0-10; P < 0.0001). For UAS, s-ketamine/midazolam was most frequently used (n = 25). Sedation score indicated minimal sedation in most cases. Overall success rate after the first attempt was 82%. Adverse events consisted of nasal burning (n = 2) and vomiting (n = 2). No serious adverse events were recorded.

CONCLUSIONS

A fentanyl-, s-ketamine-, and midazolam-based INA protocol was effective and safe for APT and UAS. It should then be considered where intravenous access is impossible or inappropriate.

Choosing Wisely in pediatric anesthesia: An interpretation from the German Scientific Working Group of Paediatric Anaesthesia (WAKKA)

Inspired by the Choosing Wisely initiative, a group of pediatric anesthesiologists representing the German Working Group on Paediatric Anaesthesia (WAKKA) coined and agreed upon 10 concise positive ("dos") or negative ("don'ts") evidence-based recommendations. (i) In infants and children with robust indications for surgical, interventional, or diagnostic procedures, anesthesia or sedation should not be avoided or delayed due to the potential neurotoxicity associated with the exposure to anesthetics. (ii) In children without relevant preexisting illnesses (ie, ASA status I/II) who are scheduled for elective minor or medium-risk surgical procedures, no routine blood tests should be performed. (iii) Parental presence during the induction of anesthesia should be an option for children whenever possible. (iv) Perioperative fasting should be safe and child-friendly with shorter real fasting times and more liberal postoperative drinking and enteral feeding. (v) Perioperative fluid therapy should be safe and effective with physiologically composed balanced electrolyte solutions to maintain a normal extracellular fluid volume; addition of 1%-2.5% glucose to avoid lipolysis, hypoglycemia, and hyperglycemia, and colloids as needed to maintain a normal blood volume. (vi) To achieve safe and successful airway management, the locally accepted airway algorithm and continued teaching and training of basic and alternative techniques of ventilation and endotracheal intubation are required. (vii) Ultrasound and imaging systems (eg, transillumination) should be available for achieving central venous access and challenging peripheral venous and arterial access. (viii) Perioperative disturbances of the patient's homeostasis, such as hypotension, hypocapnia, hypothermia, hypoglycemia, hyponatremia, and severe anemia, should not be ignored and should be prevented or treated immediately. (ix) Pediatric patients with an elevated perioperative risk, eg, preterm and term neonates, infants, and critically ill children, should be treated at institutions where all caregivers have sufficient expertise and continuous clinical exposure to such patients. (x) A strategy for preventing postoperative vomiting, emergence delirium, and acute pain should be a part of every anesthetic procedure.

Effect of age on Narcotrend Index monitoring during sevoflurane anesthesia in children below 2 years of age

BACKGROUND

In older children, different electroencephalogram-based algorithms for measuring depth of anesthesia displayed a similar performance as in adults, but in infants they have not displayed the same reliability so far. According to the individual developmental state, the Narcotrend distinguishes "differentiated" electroencephalograms, which can be classified using the full Narcotrend Index scale, from "undifferentiated" electroencephalograms, which are classified using a scale with fewer stages.

OBJECTIVE

The objective of this prospective clinical observational study was to assess the feasibility and performance of the Narcotrend monitor in children <2 years within a clinical setting.

METHODS

Sixty-one children aged 0-24 months undergoing general anesthesia with sevoflurane and remifentanil for elective pediatric surgery were studied. We investigated the percentage of differentiated electroencephalograms and the correlation between multiples of minimal alveolar sevoflurane concentration and the Narcotrend Index according to age groups. Prediction probability was used to evaluate the performance of the Narcotrend Index for differentiation between consciousness and unconsciousness and between different sevoflurane concentrations.

RESULTS

The percentage of differentiated electroencephalograms increased with increasing age (0-3 months: 23.8%, 4-5 months: 87.5%, 6-11 months: 92.3%, 12-24 months: 100%). The overall prediction probability of Narcotrend Index was 1.0 (SE 0.05) for differentiation between awake and loss of consciousness and 1.0 (SE 0.01) for differentiation between anesthetized and return of consciousness. Spearman correlation analysis revealed a significant negative correlation between sevoflurane concentration and the Narcotrend Index (r = -0.78, P < .0001, 95%CI: -0.81 to -0.74). Overall prediction probability of Narcotrend Index to sevoflurane concentration was 0.8 (95%CI: 0.78-0.82).

CONCLUSION

The Narcotrend monitor indicated a Narcotrend Index in most infants and young children starting from 4 months with significant correlation to and acceptable prediction probability for minimal alveolar sevoflurane concentration.

Compatibility of common IV drugs with 6% hydroxyethyl starch 130/0.42 and 4% gelatin

BACKGROUND

Acetate-containing colloid infusion solutions are recommended to recover normovolemia during pediatric anesthesia. Until now, no studies investigating the compatibility with common anesthetic drugs were available.

AIMS

This in vitro study was conducted to reveal possible incompatibilities between common anesthetic drugs and the acetate-containing colloid infusion solutions 6% hydroxyethyl starch and 4% gelatin with normal saline as control.

METHODS

The colloid infusion solutions were mixed 1:1 with 29 common intravenous drugs in concentrations used in daily clinical practice. Macroscopically visible changes as well as electrical conductivity, pH, and turbidimetric light diffusion at 405 nm were measured immediately after mixing and subsequently 30 and 60 minutes later. All experiments were conducted in triplicate.

RESULTS

Fifty-nine of the 87 colloid infusion-drug mixtures showed no significant changes in pH, electrical conductivity, turbidimetrically detectable light diffusion, or macroscopic appearance after mixing with hydroxyethyl starch, gelatin, and NaCl 0.9%. Fifteen mixtures showed equivocal reactions, and 13 mixtures showed incompatibility reactions.

CONCLUSION

Most of the tested drugs did not show observable incompatibility reactions. However, some common drugs are highly incompatible with colloid infusion solutions: gelatin (cefazolin, diazepam, midazolam, phenytoin, vancomycin), hydroxyethyl starch (diazepam, midazolam, phenytoin, thiopental), and NaCl 0.9% (diazepam, ketamine (S), phenytoin, thiopental). These combinations should be avoided in clinical practice in case there are fewer intravenous lines available than needed.

Impact of temperature on the Narcotrend Index during hypothermic cardiopulmonary bypass in children with sevoflurane anesthesia

Background:

During cardiopulmonary bypass (CPB) in children, anesthesia maintained by sevoflurane administered via the oxygenator is increasingly common. Anesthetic uptake and requirement may be influenced by the non-physiological conditions during hypothermic CPB. Narcotrend-processed EEG monitoring may, therefore, be useful to guide the administration of sevoflurane during this phase.

Objective:

The objective of this prospective, clinical, observational study was to assess the correlation between body temperature, Narcotrend Index (NI) and administered sevoflurane in children during CPB.

Methods:

Forty-four children aged 0 to 10 years undergoing hypothermic cardiac surgery were studied. On bypass, anesthesia was maintained with sevoflurane administered via the oxygenator of the heart-lung machine. Nasopharyngeal temperature, NI and minimum alveolar concentration (MAC) of sevoflurane were recorded in intervals of 10 minutes. Expiratory gas was sampled from the oxygenator’s sole expiratory port via a separate connecting line and the MAC was measured by the agent analyzer of the anesthesia machine.

Results:

Raw (r = 0.74) and corrected (r = 0.73) r-values show that narcosis depth (as indicated by NI) can primarily be explained by the interaction of MAC and temperature. The analysis of variance (without the interaction term) confirms the significant and independent association of both factors, MAC (p<0.004, 95%CI: 0.19 to 0.46) and temperature (p<0.0001, 95%CI: 0.68 to 0.78), with the NI. During hypothermia, sevoflurane had been reduced significantly (r = 0.41, p<0.0001, 95%CI: 0.33 to 0.48).

Conclusion:

Perfusionists and anesthetists should be aware of the results of processed electroencephalograph (EEG) monitoring during CPB. Sevoflurane requirements differ inter-individually; they may decrease during cooling and increase during rewarming. Therefore, it seems reasonable to include the results of processed EEG monitoring when administering sevoflurane during CPB in children, but further studies are necessary to confirm this thesis.

[Perioperative Intravenous Fluid Therapy in Children]

The objective of this consensus-based S1 Guideline for perioperative fluid therapy in children is to maintain or re-establish the child's homeostasis. Therefore, the perioperative fasting times should be as short as possible to prevent patient discomfort, dehydration, and ketoacidosis. For the intraoperative background infusion a physiologically composed balanced isotonic electrolyte solution (BS) with 1 - 2.5% glucose is recommended to maintain normal glucose concentrations and to avoid hyponatremia, hyperchloremia, and lipolysis. Additional BS without glucose can be used in patients with circulatory instability until the desired effect is achieved. The additional use of colloids is recommended to recover normovolemia and to avoid fluid overload when crystalloids alone are not sufficient and blood products are not indicated. Monitoring should be extended in cases with major surgery.

Ultrasound assessment of gastric emptying after breakfast in healthy preschool children

BACKGROUND

In current guidelines, 6 hours of fasting is recommended for solids to limit the risk of pulmonary aspiration during anesthesia in children. Ultrasonography has recently been introduced to evaluate gastric volumes in children in the context of preanesthetic fasting. Therefore, in this study, we firstly evaluated the precision of ultrasound assessment of gastric volume in an experimental setting and secondly studied gastric emptying times after a normal breakfast in healthy preschool children using ultrasound.

METHODS

In a preliminary experiment, a pear-shaped elastic balloon was filled and emptied in 50 mL steps from 0 to 500 mL with water. After each step, the balloon antral area was measured using ultrasonography. Thereafter, gastric emptying was examined in healthy preschool children after normal breakfast by sonographic measurements of the gastric antral area in right lateral decubitus position at two consecutive timepoints. Correlation coefficients (Pearson, 95% CI) between the balloon antral area and the balloon volume or gastric antral area and fasting time were calculated and gastric emptying time was extrapolated by linear regression. Data are presented as mean (range).

RESULTS

In the balloon experiment, the balloon volume correlated significantly with the balloon antral area (63 measurements, r=.96, P<.0001, 95% CI 0.93 to 0.97). In the preschool child measurements, a total of 30 children (age 47 (36-66) months) were included. The gastric antral area correlated significantly with fasting time (r=-.69, P<.0001, 95% CI -0.8 to -0.51). The first gastric antral area after breakfast was significantly higher when compared to the second gastric antral area before lunch (10.4 ± 3.7 (1.7-17.8) vs 5.5 ± 2.6 (1.4-11.8) cm² ; mean difference -5.04, 95% CI -6.3 to -3.8, P<.0001). The calculated mean gastric emptying time was 236 minutes.

CONCLUSION

The results of the balloon experiment showed a high correlation between balloon antral area and balloon volume. In the preschool child measurements, gastric antral area correlated with fasting time, and the mean gastric emptying time was lower than 4 hours after breakfast. These results support a more liberal perioperative fasting regimen after a light meal or breakfast in routine pediatric anesthesia.

Metamizole for Postoperative Pain Therapy in Infants Younger than 1 Year

Background Due to possible serious adverse drug reactions (ADRs), the use of metamizole for postoperative pain therapy in infants is a subject of debate. Safety studies with large sample sizes are missing. Aim This prospective multicenter observational study was conducted to evaluate the use of metamizole in infants younger than 1 year undergoing surgery with a particular focus on possible serious ADRs (e.g., hemodynamic, anaphylactic or respiratory reactions, and agranulocytosis). Methods Infants aged up to 1 year (American Society of Anesthesiologists [ASA] I-III) receiving a single dose of metamizole for postoperative pain therapy were enrolled. Patient demographics, main and secondary diagnosis, surgical procedures performed, metamizole dose, hemodynamic data, use of other analgesics and regional blocks, results of pain measurement, and incidence of ADRs were documented using a standardized case report form. Results A total of 316 infants observed at five pediatric centers were included for analysis (age 4.4 ± 3.7 [0.06-12] months). Mean metamizole dose was 17.8 ± 3.1 (9.2-29.8) mg·kg^-1. Mean arterial pressure (MAP) remained stable during metamizole infusion (MAP before infusion 45 ± 9.5 [25-95] and after infusion 45 ± 9.2 [25-99] mm Hg). Erythema was observed in one patient (ADRs total: 0.3%, 95% confidence interval: 0.27-0.32). No respiratory adverse events directly related to the metamizole administration and no clinical signs of agranulocytosis were reported. Conclusion Single intravenous doses of metamizole used for prevention or treatment of postoperative pain were safe in more than 300 infants younger than 1 year. The statistical probability of serious ADRs (e.g., hemodynamic, anaphylactic or respiratory reactions) was lower than 1%. The sample size and follow-up were not sufficient to detect agranulocytosis.

Optimization of initial propofol bolus dose for EEG Narcotrend Index-guided transition from sevoflurane induction to intravenous anesthesia in children

BACKGROUND

Sevoflurane induction followed by intravenous anesthesia is a widely used technique to combine the benefits of an easier and less traumatic venipuncture after sevoflurane inhalation with a recovery with less agitation, nausea, and vomiting after total intravenous anesthesia (TIVA). Combination of two different anesthetics may lead to unwanted burst suppression in the electroencephalogram (EEG) during the transition phase.

OBJECTIVE

The objective of this prospective clinical observational study was to identify the optimal initial propofol bolus dose for a smooth transition from sevoflurane induction to TIVA using the EEG Narcotrend Index (NI).

METHODS

Fifty children aged 1-8 years scheduled for elective pediatric surgery were studied. After sevoflurane induction and establishing of an intravenous access, a propofol bolus dose range 0-5 mg·kg^-1 was administered at the attending anesthetist's discretion to maintain a NI between 20 and 64, and sevoflurane was stopped. Anesthesia was continued as TIVA with a propofol infusion dose of 15 mg·kg^-1 ·h^-1 for the first 15 min, followed by stepwise reduction according to McFarlan's pediatric infusion regime, and remifentanil 0.25 μg·kg^-1 ·min^-1 . Endtidal concentration of sevoflurane, NI, and hemodynamic data were recorded during the whole study period using a standardized case report form. Propofol plasma concentrations were calculated using the paedfusor dataset and a TIVA simulation program.

RESULTS

Median endtidal concentration of sevoflurane at the time of administration of the propofol bolus was 5.1 [IQR 4.7-5.9] Vol%. The median propofol bolus dose was 1.2 [IQR 0.9-2.5] mg·kg^-1 and median NI thereafter was 33 [IQR 23-40]. Nine children presented with a NI 13-20 and three children with burst suppression in the EEG (NI 0-12); all of them received an initial propofol bolus dose >2 mg·kg^-1 . Regression equation demonstrated that NI 20-64 was achieved with a 95% probability when using a propofol bolus dose of 1 mg·kg^-1 after sevoflurane induction. Decrease in mean arterial blood pressure correlated significantly with propofol bolus dose (P = 0.038). After 25 min of TIVA, children younger than 2 years had a higher NI (median difference 14.0, 95%CI: 6.0-20.0, P = 0.001), higher deviations from the expected Narcotend Index (median difference 4.1, 95%CI: 3.9-4.2, P < 0.001) and lower calculated propofol plasma concentrations (median difference 0.2 μg·ml^-1 , 95% CI: 0.1-0.3 μg·ml^-1 , P < 0.001) than older children.

CONCLUSION

After sevoflurane induction, a reduced propofol bolus dose of 1 mg·kg^-1 followed by TIVA according to McFarlan's regime resulted in a NI within the recommended range in children aged 1-8 years. During the course of TIVA, children younger than 2 years displayed higher NI values and more pronounced interindividual variation. Processed EEG monitoring is recommended to find adequate individual age-dependent doses.

Perioperative intravenous fluid therapy in children: guidelines from the Association of the Scientific Medical Societies in Germany

This consensus- based S1 Guideline for perioperative infusion therapy in children is focused on safety and efficacy. The objective is to maintain or re-establish the child's normal physiological state (normovolemia, normal tissue perfusion, normal metabolic function, normal acid- base- electrolyte status). Therefore, the perioperative fasting times should be as short as possible to prevent patient discomfort, dehydration, and ketoacidosis. A physiologically composed balanced isotonic electrolyte solution (BS) with 1-2.5% glucose is recommended for the intraoperative background infusion to maintain normal glucose concentrations and to avoid hyponatremia, hyperchloremia, and lipolysis. Additional BS without glucose can be used in patients with circulatory instability until the desired effect is achieved. The additional use of colloids (albumin, gelatin, hydroxyethyl starch) is recommended to recover normovolemia and to avoid fluid overload when crystalloids alone are not sufficient and blood products are not indicated. Monitoring should be extended in cases with major surgery, and autotransfusion maneuvers should be performed to assess fluid responsiveness.

Optimized preoperative fasting times decrease ketone body concentration and stabilize mean arterial blood pressure during induction of anesthesia in children younger than 36 months: a prospective observational cohort study

BACKGROUND

In pediatric anesthesia, preoperative fasting guidelines are still often exceeded.

OBJECTIVE

The objective of this noninterventional clinical observational cohort study was to evaluate the effect of an optimized preoperative fasting management (OPT) on glucose concentration, ketone bodies, acid-base balance, and change in mean arterial blood pressure (MAP) during induction of anesthesia in children.

METHODS

Children aged 0-36 months scheduled for elective surgery with OPT (n = 50) were compared with peers studied before optimizing preoperative fasting time (OLD) (n = 50) who were matched for weight, age, and height.

RESULTS

In children with OPT (n = 50), mean fasting time (6.0 ± 1.9 h vs 8.5 ± 3.5 h, P < 0.001), deviation from guideline (ΔGL) (1.2 ± 1.4 h vs 3.7 ± 3.1 h, P < 0.001, ΔGL>2 h 8% vs 70%), ketone bodies (0.2 ± 0.2 mmol·l(-1) vs 0.6 ± 0.6 mmol·l(-1) , P < 0.001), and incidence of hypotension (MAP <40 mmHg, 0 vs 5, P = 0.022) were statistically significantly lower and MAP after induction was statistically significantly higher (55.2 ± 9.5 mmHg vs 50.3 ± 9.8 mmHg, P = 0.015) as compared to children in the OLD (n = 50) group. Glucose, lactate, bicarbonate, base excess, and anion gap did not significantly differ.

CONCLUSION

Optimized fasting times improve the metabolic and hemodynamic condition during induction of anesthesia in children younger than 36 months of age.

Compatibility of common drugs with acetate-containing balanced electrolyte solutions in pediatric anesthesia

BACKGROUND

Acetate-containing balanced electrolyte solutions are frequently used for fluid therapy in pediatric anesthesia, but no studies investigating the compatibility with common anesthetic drugs are available.

AIM

To reveal possible incompatibilities between common anesthetic drugs and the acetate-containing balanced electrolyte solutions BS (Sterofundin ISO; B.Braun Melsungen AG, Melsungen, Germany) and BS-G1 (E148G1 Päd; Serumwerk Bernburg AG, Bernburg, Germany), with normal saline (NS) as control.

METHODS

All tested infusion solutions were mixed 1 : 1 with 28 common anesthetic drugs in concentrations used in daily clinical practice. Electrical conductivity, pH, and turbidimetric light diffusion at 405 nm were measured. Macroscopic changes such as gross precipitation, change in color, or bubble formation were also assessed. All measurements were performed immediately after mixing as well as 30 and 60 min after.

RESULTS

The vast majority of drugs showed no significant change in pH, electric conductivity, turbidimetric detectable light diffusion, or macroscopic appearance after mixing with BS, BS-G1, and NS. Phenytoin immediately precipitated in response to all tested solutions as did diazepam. Thiopental precipitated after mixing with BS only.

CONCLUSIONS

Most of the tested drugs did not show any signs or evidence of incompatibility reactions. However, phenytoin and diazepam should not be in contact with the three tested solutions, including NS. Thiopental should be used with caution because it can precipitate in solutions with a low pH (e.g., BS).

Impact of high doses of 6% hydroxyethyl starch 130/0.42 and 4% gelatin on renal function in a pediatric animal model

OBJECTIVES

Despite serious renal side effects in critically ill adult patients, artificial colloids are still fundamental components of perioperative fluid therapy in infants and children, although the impact of 6% hydroxyethyl starch (HES) and 4% gelatin (GEL) on renal function during pediatric surgery has not been identified yet.

AIM

To determine the impact of high doses of artificial colloids on renal function, we conducted an experimental animal study and hypothesized that neither the infusion of HES nor of GEL would have a serious impact on renal function.

METHODS

Fifteen sedated piglets were randomly assigned to receive an infusion of either 50 ml · kg(-1) HES or GEL, or a balanced electrolyte solution (crystalloid group). Before and 1 week after infusion, serum and urine renal function tests were recorded and renal biopsies were taken.

RESULTS

Serum and urine renal function tests revealed no increase after administration of HES and GEL, and only a discrete increase in serum creatinine (median 9.8 μmol · l(-1), 95% CI 4.0-19.1) in the crystalloid group. Histopathological examination indicated a sparsely, multifocal infiltration of mononuclear cells in all groups and an unspecific pyelectasia of one animal in the GEL group.

CONCLUSIONS

After high doses of HES or GEL in piglets, no relevant impact on renal function could be found. These results confirm that AKI after HES or GEL is very unlikely in hemodynamically stable perioperative patients with normal renal function.

Impact of 6% hydroxyethyl starch 130/0.42 and 4% gelatin on renal function in a pediatric animal model

OBJECTIVES

Artificial colloids, frequently used to prevent hemorrhagic shock in children, may induce serious renal side effects in critically ill adult patients. The impact of perioperative colloid infusion on the renal function in adults and children remains unclear.

AIM

To determine the impact of single doses of artificial colloids on renal function tests, we conducted an experimental animal study. We hypothesized that neither the infusion of moderate doses of 6% hydroxyethyl starch (HES) nor of 4% gelatin (GEL) would have a serious impact on the renal function of healthy piglets.

METHODS

Fifteen sedated piglets were randomly assigned to receive an infusion of either 20 ml·kg(-1) HES or GEL or a balanced electrolyte solution (BS, control group) over 30 min. Before and 7 days after infusion, serum and urine renal function tests were recorded and renal biopsies were taken.

RESULTS

Serum and urine renal function tests (e.g., creatinine, urea, cystatin C, and neutrophil gelatinase-associated lipocalin) were within normal ranges, and a microscopic examination of the renal tissue in all groups revealed no major alterations such as tubular necrosis, interstitial bleeding, interstitial inflammation, or vacuoles.

CONCLUSIONS

In this pediatric animal model, the infusion of moderate doses of artificial colloids was not found to have any relevant impact on renal function. Further clinical investigations are necessary to provide a conclusive assessment of the risk for renal impairment after HES and GEL administration during major pediatric surgery.

Comparison of bicarbonate-buffered fluid and isotonic saline solution as Cell Saver washing fluids for packed red blood cells

OBJECTIVES

Massive transfusion (MT) can cause severe electrolyte and acid-base disturbances in neonates and infants due to the unphysiological composition of packed red blood cells (PRBCs). Washing of the PRBCs using Cell Saver systems prior to MT is recommended for this reason.

AIM

The composition of normal saline (NaCl), the standard wash fluid for Cell Saver systems, is considerably different from that of physiological plasma. The aim of the study presented here was to investigate the effect of washing the PRBCs with a bicarbonate-buffered hemofiltration solution (BB-HS) in comparison with washing with NaCl and to evaluate the impact on electrolyte concentrations, acid-base balance and the stability of PRBCs.

METHODS

In an experimental in vitro setting, PRBCs were washed with Cell Saver systems prepared with NaCl or BB-HS as washing solutions. Before and after the washing procedure, electrolyte concentrations, acid-base parameters, adenosine triphosphate (ATP) and free hemoglobin (fHb) concentrations were measured.

RESULTS

In both groups, the potassium concentrations decreased (baseline: 18.4 ± 5.17 mmol·l(-1), end of study: NaCl 2.71 ± 1,81 mmol·l(-1), BB-HS 2.50 ± 1.54 mmol·l(-1), P < 0.05) while the acid-base balance improved only in the BB-HS-group (baseline: base excess -21.6 ± 3.52 mmol·l(-1), end of study: NaCl -30.2 ± 1.42 mmol·l(-1), BB-HS -7.51 ± 2.49 mmol·l(-1) , P < 0.05). Furthermore, markers of erythrocyte stability such as fHb and ATP concentrations were improved in the BB-HS-group.

CONCLUSIONS

Washing of PRBCs with BB-HS rather than NaCl results in a more physiological composition with improvements of electrolyte concentrations, acid-base balance and erythrocyte stability.

Prevention of intraoperative hypothermia in neonates and infants: results of a prospective multicenter observational study with a new forced-air warming system with increased warm air flow

OBJECTIVES

Neonates and infants are at the highest risk of developing perioperative hypothermia. A number of methods to prevent hypothermia during pediatric anesthesia are in use, and despite the fact that conventional forced-air warmers are the most effective devices, they are not always sufficient enough to maintain body temperature. Therefore, recently a new forced-air warming system with an increased warm air flow was introduced to the market.

AIM

The aim of this study was to evaluate this new forced-air warming system in neonates and infants during pediatric anesthesia. We hypothesized that the new blanket alone is sufficient enough to prevent neonates and infants from intraoperative hypothermia.

METHODS

Neonates and infants (body weight <10 kg) were enrolled in this prospective multicenter observational study. After admission to the operating room, the children were placed on the new forced-air warming blanket. Body temperature was measured continuously until admission to the recovery room or pediatric intensive care unit (PICU).

RESULTS

Hundred and nineteen children with a median body weight of 4.1 kg (range: 0.7-9.8) were enrolled and received their intended treatment. Median body temperature at the induction of anesthesia was 36.5 °C (range: 35.3-38.2 °C) and increased with the length of the operation up to 37.8 °C (37.1-38.2 °C) after 180 min. Median body temperature after admission to the recovery room or PICU was 37.2 °C (36.0-38.6 °C) and remained significantly above baseline (P < 0.05).

CONCLUSIONS

The new forced-air warming system as a sole warming device is effective in preventing perioperative hypothermia during pediatric anesthesia in neonates and infants.

[Effects of intravenous clonidine on recovery and postanaesthetic analgesic requirements.]

Pain and pain-related sympathoadrenergic reactions (hypertension, tachycardia) accompanied by nausea, vomiting and shivering are the most common side effects of recovery from anaesthesia. The alpha(2)agonist clonidine acts as a sedative, anxiolytic, antihypertensive, antiemetic, antisialogogue and decreases the incidence of shivering. Thus, we studied the effects of intraoperatively administered clonidine on the recovery period and the postoperative analgesic requirements in patients undergoing maxillofacial surgery.

METHODS

After approval by the local Ethics Commitee and after informed consent had been given, 40 patients scheduled for elective maxillofacial surgery were included in this double-blind, randomized study. As a supplement to standardized general anaesthesia (isoflurane, N(2)O), the patients received either clonidine 5 mug/kg or placebo during the last hour of the operation. Blood pressure, heart rate, time of recovery, and sedation and pain scores were measured postoperatively. The occurrence of nausea, vomiting or shivering was noted, as were the requirements of piritramide for analgesia, which was administered on demand in titrating dosages, and of nifedipine for systolic blood pressure exceeding 180 mm Hg.

RESULTS

The two groups were comparable regarding biometric parameters, ASA-classification and duration of anaesthesia. Clonidinetreated patients were later in opening their eyes (22.5+/-11.9 min vs 17.9+/-10.9; n.s.) and the ability to state their dates of birth returned later (32.2+/-11.6 min vs. 25.7+/-12.8;P<0.05). Pain was more frequent in the placebo group (P<0.05 after 30 min), and there-fore, these patients required much more piritramid (P<0.01). The sedation scores showed no significant differences. No vomiting occurred in the clonidine group, and shivering was less frequent (P<0.01). The placebo group received more nifedipine (P<0.05) because the rate-pressure product was higher (P<0.01).

DISCUSSION

Opiates are frequently used as analgesics after maxillofacial surgery, even though their most common side effect-respiratory depression, nausea and vomiting-are particularly dangerous in these patients because of the obstruction of the upper respiratory tract. Self-titration of the opiate dosage on demand can decrease the incidence of serious side effects. Clonidine administered intraoperatively caused a profound reduction in analgesic requirements in this study. Additional opiate administration in the postoperative period was unnecessary in nearly all clonidine-treated patients. The attenuating effect on sympathoadrenergic reactions leads to lowering of the rate-pressure product and may be of advantage for patients suffering from arterial hypertension, angina pectoris or bronchial asthma. The slower emergence from anaesthesia following clonidine administration is probably caused by double-blind study properties preventing full consideration of the decreased isoflurane requirements after clonidine.

Single-lung ventilation with carbon dioxide hemipneumothorax: hemodynamic and respiratory effects in piglets

OBJECTIVES

Video-assisted thoracoscopic surgery (VATS) has become a standard procedure in pediatric surgery. To facilitate surgical access, the dependent lung has to collapse using intrathoracic carbon dioxide insufflation and/or single-lung ventilation. These procedures can induce hemodynamic deteriorations in adults. The potential impacts of single-lung ventilation in combination with capnothorax on hemodynamics in infants have never been studied before.

AIM

We conducted a randomized experimental study focusing on hemodynamic and respiratory changes during single-lung ventilation with or without capnothorax in a pediatric animal model.

METHODS

Twelve piglets were randomly assigned to receive single-lung ventilation with (SLV-CO(2) ) or without (SLV) capnothorax with an insufflation pressure of 5 mmHg for a period of two hours. Before, during, and after single-lung ventilation, hemodynamic and respiratory parameters were measured.

RESULTS

Although mean arterial pressure remained stable during the course of the study and no critical incidents were monitored, cardiac index (CI) decreased significantly with SLV-CO(2) (baseline 3.6 ± 1.6 l · min(-1) · m(-2) vs 2.9 ± 1.1 l · min(-1) · m(-2) at 120 min, P < 0.05). Furthermore, global end-diastolic volume and intrathoracic blood volume (ITBV) decreased as well significantly with SLV-CO(2) , causing a significant between-group difference in ITBV (P < 0.05).

CONCLUSIONS

Despite a decrease in CI and preload parameters, the combination of single-lung ventilation and low-pressure capnothorax was well tolerated in piglets and could justify further clinical studies to be performed in infants and children focusing on hemodynamic and respiratory changes during VATS.

Comparison of transpulmonary thermodilution and ultrasound dilution technique: novel insights into volumetric parameters from an animal model

Especially in critically ill children with cardiac diseases, fluid management and monitoring of cardiovascular function are essential. Ultrasound dilution technique (UDT) was recently introduced to measure cardiac output (CO) and volumetric parameters, such as intrathoracic and end-diastolic blood volume. We compared UDT with the well-established transpulmonary thermodilution (TPTD) method (PiCCO) for determining CO measurements and derived volumes in a juvenile animal model. Experiments were performed in 18 ventilated, anesthetized piglets during normovolemia and after isovolemic hemodilution. At baseline and 20 min after each step of isovolemic hemodilution, 3 independent measurements of CO and volumetric parameters were conducted with TPTD and UDT, consecutively, under hemodynamically stable conditions. We observed comparable results for CO measurements with both methods (mean 1.98 l/min; range 1.12-2.87) with a percentage error of 17.3% (r = 0.92, mean bias = 0.28 l/min). Global end-diastolic volume (GEDV) and intrathoracic blood volume (ITBV) by TPTD were almost two times greater than analogous volumes [central blood volume (CBV); total end-diastolic volume (TEDV)] quantified by UDT (CBV = 0.58 × ITBV + 27.1 ml; TEDV = 0.48 × GEDV + 23.1 ml). CO measurements by UDT were found to be equivalent and hence interchangeable with TPTD. Discrepancies in volumetric parameters could either be due to the underlying algorithm or different types of indicators (diffusible vs. nondiffusible). Compared with the anatomically defined heart volume, TPTD seems to overestimate end-diastolic volumes. Future studies will be necessary to assign these results to critically ill children and to validate volumetric parameters with reference techniques.

Isovolaemic hemodilution with gelatin and hydroxyethylstarch 130/0.42: effects on hemostasis in piglets

OBJECTIVES

Artificial colloids, frequently used to prevent hemorrhagic shock in children, impair blood coagulation. To determine the impact of acute isovolaemic hemodilution with artificial colloids on clot formation, we conducted an experimental study in a pediatric animal model.

METHODS

Fifteen piglets underwent hemorrhage by withdrawing 40 ml·kg(-1) of blood volume in steps of 10 ml·kg(-1) each within 1 hour. After each withdrawal, the blood loss was randomly compensated by administering 4% gelatin (GEL) or hydroxylethyl starch 130/0.42 (HES) in a ratio of 1 : 1, or isotonic crystalloid solution (ICS) in a ratio of 1 : 4 for isovolaemic hemodilution. Quality of clot formation and platelet function was measured using Thrombelastometry (ROTEM(®)) and Multiple electrode impedance aggregometry (Multiplate(®)) after 10, 20, and 40 ml·kg(-1) blood replacement.

RESULTS

Moderate hemodilution (10-20 ml·kg(-1) blood replacement) caused no significant differences among groups (e.g. INTEM(®)-MCF after 20 ml·kg(-1) blood replacement (ICS vs GEL vs HES, P > 0.05). Profound hemodilution with 40 ml·kg(-1) blood replacement showed a significant difference between ICS and both colloids (P < 0.05), but no significant differences between GEL and HES.

CONCLUSIONS

Impairment of clot formation by moderate isovolaemic hemodilution did not significantly differ between ICS, GEL, and HES. Profound hemodilution of more than 50% of the estimated blood volume with GEL and HES caused significant impairment of clot formation in comparison to ICS and has to be considered when using high amounts of these synthetic colloids.

Hydroxyethyl starch 130/0.42/6:1 for perioperative plasma volume replacement in 1130 children: results of an European prospective multicenter observational postauthorization safety study (PASS)

INTRODUCTION

Third-generation hydroxyethyl starch (HES) is now approved also for the use in children, but safety studies including large numbers of pediatric patients are still missing. Therefore, we performed an European multicentric prospective observational postauthorization safety study (PASS) to evaluate the use of HES 130/0.42/6:1 in normal saline (ns-HES) or a balanced electrolyte solution (bal-HES) in children undergoing surgery.

METHODS

Children aged up to 12 years with ASA risk scores of I-III receiving ns-HES (Venofundin 6%; Braun) or bal-HES (Tetraspan 6%; Braun) were followed perioperatively. Demographic data, surgical procedures performed, anesthesia, hemodynamic and laboratory data, adverse events (AE), and adverse drug reactions (ADR) were documented using a standardized case report form.

RESULTS

Of 1130 children studied at 11 European pediatric centers from 2006 to 2009 (ns-HES, 629 children; bal-HES, 475 children; mean age, 3.6 ± 3.8 [range, day of birth-12 years]; and body weight, 15.4 ± 13 [0.9-90 kg]), 1104 were included for analysis. The mean infused HES volume was 10.6 ± 5.8 (0.83-50) ml·kg(-1). In the 399 (36.1%) cases with blood gas analysis before and after HES infusion, hemoglobin and strong ion difference decreased significantly in both groups, whereas bicarbonate and base excess (BE before infusion: ns-HES -1.8 ± 3.1, bal-HES -1.2 ± 3.3 mm; after infusion: ns-HES -2.5 ± 2.8; bal-HES -1.1 ± 3.2 mm, P < 0.05) decreased only with ns-HES but remained stable with bal-HES. Chloride concentrations increased in both groups and were significantly higher with ns-HES (Cl before infusion: ns-HES 105.5 ± 3.6, bal-HES 104.9 ± 2.9 mm; Cl after infusion: ns-HES 107.6 ± 3.4, bal-HES 106.3 ± 2.9 mm, P < 0.05). For the AE/ADR rates, dose-response but no age relationships could be demonstrated. No serious and no severe ADR directly related to HES (i.e. anaphylactoid reaction, clotting disorders, renal failure) were observed.

CONCLUSION

Moderate doses of HES 130/0.42/6:1 for perioperative plasma volume replacement seem to be safe even in neonates and small infants. The probability of serious ADR is lower than 0.3%. Changes in acid-base balance may be decreased when HES is used in an acetate-containing balanced electrolyte solution instead of normal saline. Caution should be exercised in patients with renal function disturbances and those with an increased bleeding risk.

A novel isotonic balanced electrolyte solution with 1% glucose for intraoperative fluid therapy in neonates: results of a prospective multicentre observational postauthorisation safety study (PASS)

BACKGROUND

Neonates have a higher metabolic rate and an increased risk of perioperative hypoglycemia and lipolysis, but during anesthesia, both oxygen consumption and metabolic rate are decreased, and this may lead to reduced intraoperative glucose requirements.

OBJECTIVE

The objective of this prospective multicentre observational postauthorisation safety study was to evaluate the intraoperative use of a novel isotonic balanced electrolyte solution with a low glucose concentration of 1% (BS-G1) in neonates with a particular focus on changes in acid-base, electrolyte, and glucose concentrations.

METHODS

Following the local ethics committee approval, neonates with a postmenstrual age under 45 weeks and an ASA risk score of I-IV undergoing intraoperative administration of BS-G1 were enrolled. Patient demographics, the performed procedure, adverse drug reactions, hemodynamic data, and the results of blood gas analysis before and after infusion were documented with a focus on changes in acid-base, electrolyte, and glucose concentrations.

RESULTS

  In 66 neonates (ASA I-IV; postmenstrual age 38 ± 4, range 25-45 weeks; body weight 2.9 ± 0.9, range 0.65-4.6 kg), the mean infusion rate was 10.4 ± 3.2 (range 4.5-19.6) ml·kg(-1) ·h(-1) BS-G1. During the infusion, hemoglobin, hematocrit, bicarbonate, base excess, anion gap, strong ion difference, and calcium decreased, and chloride and glucose increased significantly within the physiological range. All other measured parameters including sodium and lactate remained stable. Neither hypoglycemia (glucose < 3 mm) nor hyperglycemia (glucose > 10 mm) was documented after BS-G1 infusion. No adverse drug reactions were reported.

CONCLUSION

The study shows that the intraoperative use of an isotonic balanced electrolyte solution with 1% glucose and a mean infusion rate of 10 ml·kg(-1) ·h(-1) helps to avoid acid-base dysbalance, hyponatraemia, hypoglycemia, ketoacidosis, and hyperglycemia in surgical neonates. A careful intraoperative monitoring and adaptation of the infusion rate as needed is crucial because the glucose and fluid requirements may vary widely between subjects.

Alterations of acid-base balance, electrolyte concentrations, and osmolality caused by nonionic hyperosmolar contrast medium during pediatric cardiac catheterization

OBJECTIVE

This prospective clinical observational study was conducted to investigate the effects of contrast medium on acid-base balance, electrolyte concentrations, and osmolality in children.

BACKGROUND

For pediatric cardiac catheterization, high doses of nonionic hyperosmolar contrast medium are widely used.

METHODS

Forty pediatric patients (age 0-16 years) undergoing cardiac angiography with more than 3 ml·kg(-1) of nonionic hyperosmolar contrast medium (Iomeprol) were enrolled, and the total amount of the contrast agent given was documented. Before and after contrast medium administration, a blood sample was collected to analyze electrolytes, acid-base parameters, osmolality, hemoglobin, and hematocrit.

RESULTS

After cardiac catheterization, pH, hemoglobin, hematocrit, bicarbonate, base excess, sodium, chloride, calcium, anion gap and strong ion difference decreased, whereas osmolality increased significantly (base excess -1.8 ± 1.8 vs -3.4 ± 2.3, sodium 138 ± 2.9 vs 132 ± 4.1 mm, osmolality 284 ± 5.7 vs 294 ± 7.6 mosmol·kg(-1), P < 0.01). Seventy-eight percent of the children developed hyponatremia (sodium <135 mm). No changes were seen in pCO(2) , lactate, and potassium levels.

CONCLUSIONS

Regarding the differential diagnosis of metabolic disturbances after pediatric cardiac catheterization, low-anion gap metabolic acidosis and hyponatremia should be considered as a possible side effect of the administered contrast medium.

A novel isotonic-balanced electrolyte solution with 1% glucose for intraoperative fluid therapy in children: results of a prospective multicentre observational post-authorization safety study (PASS)

BACKGROUND

The recommendations for intraoperative fluid therapy in children have been adapted from hypotonic to isotonic electrolyte solutions with lower glucose concentrations (1-2.5% instead of 5%) to avoid hyponatremia and hyperglycemia.

OBJECTIVE

The objective of this prospective multicentre observational post-authorization safety study was to evaluate the intraoperative use of a novel isotonic-balanced electrolyte solution with 1% glucose (BS-G1) with a particular focus on changes in acid-base status, electrolyte and glucose concentrations.

METHODS

Following local ethics committee approval, pediatric patients aged up to 4 years with an ASA risk score of I-III undergoing intraoperative administration of BS-G1 were enrolled. Patient demographics, the performed procedure, adverse drug reactions, hemodynamic data, and the results of blood gas analysis before and after infusion were documented with a focus on changes in acid-base status, electrolyte and glucose concentrations.

RESULTS

In 107 patients (ASA I-III; age 16.2 ± 15.4, range day of birth to 47.7 months; body weight 8.8 ± 4.8, range 1.6-18.8 kg), the mean volume infused was 20 ± 12.6 (range 3.6-83.3) ml·kg(-1) BS-G1. During the infusion, hemoglobin, hematocrit, anion gap, strong ion difference, and calcium decreased and chloride and glucose increased significantly within the physiologic range. All other measured parameters including sodium, bicarbonate, base excess, and lactate remained stable. Neither hypoglycemia (glucose <2.5 mmol·l(-1) ) nor hyperglycemia (glucose >10 mmol·l(-1) ) was documented after BS-G1 infusion. No adverse drug reactions were reported.

CONCLUSION

The studied isotonic-balanced electrolyte solution with 1% glucose helps to avoid perioperative acid-base imbalance, hyponatremia, hyperglycemia, and ketoacidosis in infants and toddlers and may therefore enhance patient safety.

A novel isotonic-balanced electrolyte solution with 1% glucose for perioperative fluid management in children- an animal experimental preauthorization study

BACKGROUND

The recommendations for perioperative maintenance fluid in children have been adapted from hypotonic to isotonic electrolyte solutions with lower glucose concentrations (1-2.5% instead of 5%) to avoid hyponatremia or hyperglycemia.

OBJECTIVE

The objective of this prospective animal study was to determine the margin of safety of a novel isotonic-balanced electrolyte solution with 1% glucose (BS-G1) in comparison with normal saline with 1% glucose (NS-G1) in the case of accidental hyperhydration with a focus on acid-base electrolyte balance, glucose concentration, osmolality and intracranial pressure in piglets.

METHODS

Ten piglets (bodyweight 11.8 +/- 1.8 kg) were randomly assigned to receive either 100 ml.kg(-1) of BS-G1 or NS-G1 within one hour. Before, during and after fluid administration, electrolytes, lactate, hemoglobin, hematocrit, glucose, osmolality and acid-base parameters were measured.

RESULTS

Unlike BS-G1, administration of NS-G1 produced mild hyperchloremic acidosis (base excess BS-G1 vs NS-G1, baseline 1.9 +/- 1.7 vs 2.9 +/- 0.9 mmol.l(-1), study end 0.2 +/- 1.7 vs -2.7 +/- 0.5 mmol.l(-1), P < 0.05, chloride BS-G1 vs NS-G1 baseline 102.4 +/- 3.4 vs 102.0 +/- 0.7 mmol.l(-1), study end 103.4 +/- 1.8 vs 109.0 +/- 1.4 mmol.l(-1)P < 0.05). The addition of 1% glucose led to moderate hyperglycemia (P < 0.05) with a concomitant increase in serum osmolality in both groups (P < 0.05).

CONCLUSION

Both solutions showed a wide margin of safety in the case of accidental hyperhydration with less acid-base electrolyte changes when using BS-G1. This novel solution could therefore enhance patient's safety within the scope of perioperative volume management.

Changes in acid-base, electrolyte and hemoglobin concentrations during infusion of hydroxyethyl starch 130/0.42/6 : 1 in normal saline or in balanced electrolyte solution in children

INTRODUCTION

A balanced volume replacement strategy is a well established concept for correcting hypovolemia using plasma adapted isotonic crystalloid solutions with a physiological electrolyte pattern and acetate as bicarbonate precursor. Recently, third-generation hydroxyethyl starch (HES) has also become available in a balanced electrolyte solution instead of normal saline. Therefore, in this prospective non-interventional clinical study, the perioperative administration of HES 130/0.42/6 : 1 in normal saline (ns-HES) and in balanced electrolyte solution (bal-HES) was evaluated in children with a focus on acid-base, electrolyte and hemoglobin changes.

METHODS

Following local ethics committee approval, pediatric patients aged up to 12 years with an ASA risk score of I-III undergoing perioperative administration of HES (ns-HES from May 2006 to December 2007, bal-HES from January 2008 to January 2009) were included. Patient demographics, the performed procedure, adverse drug reactions, hemodynamic data and the results of blood gas analysis were documented with a focus on changes in acid-base, electrolyte and hemoglobin concentrations.

RESULTS

Of 396 enrolled patients (ASA I-III; age 2.3 +/- 3, range day of birth - 12 years; body weight 10.8 +/- 9, range 0.9-52 kg), 249 received ns-HES and 147 bal-HES (mean volume infused 9.9 +/- 4 and 9.4 +/- 6.9 ml x kg(-1), respectively). After HES infusion, hemoglobin decreased in both groups, whereas bicarbonate and base excess (BE) decreased only with ns-HES and remained stable with bal-HES (BE before infusion: ns-HES -1.8 +/- 2.8, bal-HES -1.7 +/- 2.7 mmol x l(-1); after infusion: ns-HES -2.6 +/- 2.4; bal-HES -1.6 +/- 2.6 mmol x l(-1), P < 0.05). Chloride (Cl) concentrations increased in both groups and were significantly higher with ns-HES (Cl before infusion: ns-HES 105.6 +/- 3.7, bal-HES 105.1 +/- 2.8 mmol x l(-1); after infusion: ns-HES 107.7 +/- 3.2, bal-HES 106.3 +/- 2.9 mmol x l(-1), P < 0.01). No serious adverse drug reactions were observed.

CONCLUSION

Infusion related iatrogenic acid-base and electrolyte alterations can be minimized by using hydroxyethyl starch in a balanced electrolyte solution instead of normal saline.