Achim Schmitz

University Children's Hospital Basel, Bâle, Basel-City, Switzerland

Are you Achim Schmitz?

Claim your profile

Publications (38)79.82 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A rating scale for thirst and hunger was evaluated as a noninvasive, simple and commonly available tool to estimate preanesthetic gastric volume, a surrogate parameter for the risk of perioperative pulmonary aspiration, in healthy volunteer school age children. Numeric scales with scores from 0 to 10 combined with smileys to rate thirst and hunger were analyzed and compared with residual gastric volumes as measured by magnetic resonance imaging and fasting times in three settings: before and for 2 h after drinking clear fluid (group A, 7 ml/kg), before and for 4 vs 6 h after a light breakfast followed by clear fluid (7 ml/kg) after 2 vs 4 h (crossover, group B), and before and for 1 h after drinking clear fluid (crossover, group C, 7 vs 3 ml/kg). In 30 children aged 6.4-12.8 (median 9.8) years, participating on 1-5 (median two) study days, 496 sets of scores and gastric volumes were determined. Large inter- and intra-individual variations were seen at baseline and in response to fluid and food intake. Significant correlations were found between hunger and thirst ratings in all groups, with children generally being more hungry than thirsty. Correlations between scores and duration of fasting or gastric residual volumes were poor to moderate. Receiver operating characteristic (ROC) analysis revealed that thirst and hunger rating scales cannot predict gastric content. Hunger and thirst scores vary considerably inter- and intra-individually and cannot predict gastric volume, nor do they correlate with fasting times in school age children.
    Pediatric Anesthesia 03/2014; 24(3):309-15. · 2.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine the prevalence, spectrum and course of cerebral lesions in neonates with congenital heart disease (CHD) undergoing full flow cardiopulmonary bypass (CPB) surgery using magnetic resonance imaging (MRI) and to examine the correlation between cerebral lesions and clinical neurological abnormalities. Prospective cohort study of neonates with d-transposition of the great arteries (n = 22), univentricular heart malformation with hypoplastic aortic arch (n = 6) and aortic arch obstructions (n = 2) undergoing CPB. Neonates underwent cerebral MRI and blinded standardized neurological examination before (median day 6) and after surgery (day 13). The MRI findings were compared with those of 20 healthy controls. Preoperative cerebral lesions were present in 7 of 30 patients (23%) with isolated mild or moderate white matter injury (WMI) (n = 4), isolated small cerebral stroke (n = 1) and combined WMI and stroke (n = 2). None of the healthy controls had cerebral lesions on MRI. CHD neonates with preoperative cerebral lesions had more neurological abnormalities (P = 0.01) than neonates without cerebral lesions. Low arterial oxygen saturation (P = 0.03) was a risk factor for preoperative cerebral lesions, while balloon atrioseptostomy (P = 0.19) was not. After surgery, preoperative cerebral lesions persisted in 5 of 7 neonates, and 2 neonates (7%) showed signs of additional WMI in their postoperative MRI. In neonates with severe CHD, WMI was the predominant preoperative finding, while cerebral strokes were less frequent. New postoperative lesions were rare. Preoperative neurological abnormalities correlated with the presence of cerebral lesions on MRI.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 09/2013; · 2.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Classic rapid sequence induction puts pediatric patients at risk of cardiorespiratory deterioration and traumatic intubation due to their reduced apnea tolerance and related shortened intubation time. A 'controlled' rapid sequence induction and intubation technique (cRSII) with gentle facemask ventilation prior to intubation may be a safer and more appropriate approach in pediatric patients. The aim of this study was to analyze the benefits and complications of cRSII in a large cohort. METHODS: Retrospective cohort analysis of all patients undergoing cRSII according to a standardized institutional protocol between 2007 and 2011 in a tertiary pediatric hospital. By means of an electronic patient data management system, vital sign data were reviewed for cardiorespiratory parameters, intubation conditions, general adverse respiratory events, and general anesthesia parameters. RESULTS: A total of 1001 patients with cRSII were analyzed. Moderate hypoxemia (SpO2 80-89%) during cRSII occurred in 0.5% (n = 5) and severe hypoxemia (SpO2 <80%) in 0.3% of patients (n = 3). None of these patients developed bradycardia or hypotension. Overall, one single gastric regurgitation was observed (0.1%), but no pulmonary aspiration could be detected. Intubation was documented as 'difficult' in two patients with expected (0.2%) and in three patients with unexpected difficult intubation (0.3%). The further course of anesthesia as well as respiratory conditions after extubation did not reveal evidence of 'silent aspiration' during cRSII. CONCLUSION: Controlled RSII with gentle facemask ventilation prior to intubation supports stable cardiorespiratory conditions for securing the airway in children with an expected or suspected full stomach. Pulmonary aspiration does not seem to be significantly increased.
    Pediatric Anesthesia 06/2013; · 2.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cross-sectional gastric antral area (GAA) measurements by ultrasonography (US) have been proposed for preoperative assessment of gastric volume in adults but not been validated in children. This study investigates whether in children gastric volumes can be predicted by US performed in different patient positions. Gastric fluid and air volumes were examined by magnetic resonance imaging before or up to 120 min after ingestion of 7 ml·kg(-1) diluted raspberry syrup in healthy volunteers who had fasted overnight. GAA was measured with US three times each in supine (SUP), elevated 45° degree supine (E45) and right decubital (RDC) position using imaging planes defined by vascular landmarks. Correlation coefficients (Pearson) between GAA and gastric volumes were calculated and Bland-Altman analysis performed. Sixteen children aged from 6.4 to 12.8 (9.2) years were included in 23 examinations: 6 after overnight fasting, 3 directly after, and 14 with a delay of 74 ± 35 min after fluid intake. GAA was 221 ± 116, 218 ± 112, and 347 ± 188 mm(2) for SUP, E45, and RDC position, respectively. The best correlation between body weight corrected total gastric/gastric fluid volume (TGV(w)/GFV(w)) with GAA was found for RDC position (R = 0.79; P < 0.01/R = 0.78; P < 0.01). Bias and precision of calculated and measured GFV(w) was 0 ± 2.8 ml·kg(-1). Correlations between GAA and TGV(w) or GFV(w) in children are best in the RDC position, but not sufficient to predict GFV(w) with a given GAA. Interpretation of isolated GAA values may be misleading.
    Pediatric Anesthesia 02/2012; 22(2):144-9. · 2.44 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Gastric emptying in the first 2 h after 7 ml kg(-1) of sugared clear fluid has recently been investigated in healthy children using magnetic resonance imaging (MRI). This study aims to compare gastric volume and emptying half-life during 1 h after 3 or 7 ml kg(-1) sugared clear fluid intake. Fourteen healthy volunteer children aged 11.1 (8.2-12.5) yr were investigated prospectively after administration of 3 and 7 ml kg(-1) diluted raspberry syrup in a randomized order, after overnight fasting (baseline). Gastric content volume (GCV(w)) was assessed with a 1.5 Tesla MRI scanner in a blinded fashion. Data are presented as median (range) and compared using the Wilcoxon test. Baseline GCV(w) was 0.39 (0.04-1.00) and 0.34 (0.07-0.75) before intake of 3 and 7 ml kg(-1) syrup, respectively (P=0.93). GCV(w) was 0.45 (0.04-1.55)/1.33 (0.30-2.60) ml kg(-1) 60 min after ingestion of 3/7 ml kg(-1) syrup (P=0.002). Thus GCV(w) had declined to baseline after 3 ml kg(-1) (P=0.39) but not after 7 ml kg(-1) (P=0.001) within 60 min. T(1/2) was 20 (10-62)/27 (13-43) min (P=0.73) after 3/7 ml kg(-1). In healthy volunteer children, residual GCV(w) 1 h after intake of 3 ml kg(-1) syrup is significantly smaller than that after 7 ml kg(-1) and within the range of baseline.
    BJA British Journal of Anaesthesia 01/2012; 108(4):644-7. · 4.24 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Droperidol had been used as an effective antiemetic since the 1970s but was withdrawn from the market in 2001 because of a black box warning about QT prolongation and possible cardiac arrhythmia after high doses. In the meantime the black box warning has seriously been questioned and parenteral droperidol has again been licensed in 2008. Because droperidol acts on dopaminergic receptors different to 5-HT(3) antagonists and dexamethasone, it could possibly serve as a rescue drug after failed postoperative nausea and vomiting (PONV) prophylaxis. Persistent PONV after the recommended prophylaxis is a significant problem in pediatric anesthesia but a satisfactory strategy has not yet been defined. Therefore a retrospective audit was performed in order to evaluate whether low-dose droperidol (10 µg/kgBW) would be an effective rescue drug for failed antiemetic prophylaxis. The electronic anesthesia patient data base of the University Children's Hospital Zurich was searched from 2004-2009 for patients who received low-dose droperidol in the postanesthesia care unit as rescue therapy for persistent PONV after antiemetic prophylaxis. Based on the recorded electronic data the effectiveness of low-dose droperidol as PONV rescue therapy and possible side effects were analyzed. A total of 338 patients who received droperidol were found from a total of 34,032 patients and the charts were analyzed. Of these patients 134 were excluded because they had received droperidol for indications other than PONV, 43 patients were excluded because they had not received antiemetic prophylaxis before droperidol and in 17 patients the data were incomplete, leaving 144 patients with an average age of 12.3 years (interquartile range IQR 9.5-15.2 years) for analysis. The upper range of ages resulted from patients with chronic diseases who were still being treated in the Children's Hospital. Low-dose droperidol was given because of persistent nausea to 59 patients (41%) and to 85 patients (59%) for persistent vomiting. Initial antiemetic prophylaxis and/or therapy had consisted of dexamethasone plus tropisetrone in 80 patients and tropisetrone or dexamethasone alone in 64 patients. In 128 patients (89%) rescue therapy with a median dose of 10.9 µg/kgBW droperidol was effective but vomiting persisted in 16 patients (11%). Sedation was the only side effect recorded and this was observed in 39 patients (27%). Low-dose droperidol (10 µg/kgBW) was found to be effective as rescue medication in pediatric patients experiencing PONV despite various prophylactic antiemetic regimens. No neurological or cardiopulmonary side effects were recorded after this low dosage.
    Der Anaesthesist 01/2012; 61(1):30-4. · 0.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: While American Society of Anesthesiologists and European Society of Anaesthesiology guidelines recommend 6 h pre-anaesthetic fasting for food and non-clear fluids in children, some institutions allow shorter fasting times of 4 h. Aim of this pilot study was to compare weight-indexed residual gastric contents volumes (GCV(w)) after 4 vs. 6 h after a light breakfast, using magnetic resonance imaging (MRI) in healthy volunteer children not scheduled for anaesthesia. Four vs. 6 h (F(4) /F(6)) of food fasting were simulated in a crossover study. After overnight fasting (baseline), each child ingested a light breakfast (cereal flakes, milk products) on two separate days. Additional clear fluid (7 ml/kg raspberry syrup) was given either after 2 (F(4) ) or 4 h (F(6) ), followed by half-hourly MRI acquisition for 2 h. MRI was obtained on a 1.5 Tesla scanner as 5 mm axial images (FIESTA) and volumes were traced manually by one blinded observer. Data are given as median (range) or mean ± standard deviation. Eighteen healthy volunteers aged 9.0 (6.8-12.2) years participated. GCV(w) for F(4) and F(6) at baseline was 0.50 ± 0.27 and 0.76 ± 0.48 ml/kg (P = 0.07), respectively, GCV(w) after 4 and 6 h was 0.72 ± 0.85 and 0.47 ± 0.25 ml/kg (P = 0.88). T(1/2) after syrup intake was 30.8 ± 12.2 and 28.3 ± 5.7 min (P = 0.47) for F(4) and F(6) , respectively. Residual gastric contents volumes at a hypothetical anaesthesia start were similar for 4 and 6 h food fasting in healthy volunteer school-age children.
    Acta Anaesthesiologica Scandinavica 12/2011; 56(5):589-94. · 2.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Current guidelines recommend preoperative fasting of 2 h for clear fluids, which is often exceeded in routine clinical practice. Existing data on residual gastric volumes in children do not consider fluid intake within <2 h and rely on the aspiration of gastric contents via a gastric tube. This study evaluated the emptying of clear fluids from the stomach using magnetic resonance imaging (MRI). Healthy volunteers aged 6-14 years were asked to fast overnight. MRI scans to assess gastric volumes were obtained before and immediately after drinking 7 ml kg(-1) of diluted raspberry syrup and then every 30 min up to 120 min. Volumes were determined by a blinded investigator and indexed gastric fluid/air volumes (GFV(w)/GAV(w)) and half-life (t(1/2)) of GFV(w) course after clear fluid intake were calculated. Sixteen children, median age 9.2 (range 6.4-12.8) years, were investigated. Median (range) GFV(w) was 0.62 (0.15-0.97) ml kg(-1) before and 6.68 (4.77-7.78) ml kg(-1) immediately after fluid intake, and 2.92 (0.43-5.04), 1.27 (0.28-3.62), 0.42 (0.07-2.49), and 0.32 (0.04-1.13) ml kg(-1) 30, 60, 90, and 120 min thereafter. Median GFV(w) declined exponentially (t(1/2)=26.1 min). Median individual t(1/2) was 23.6 (range 17.9-47.8) min. GAV(w) showed considerable intra- and inter-individual variation. In healthy school children, gastric emptying after ingestion of clear fluid occurs with a median half-life time of <30 min but with considerable inter-individual variation.
    BJA British Journal of Anaesthesia 06/2011; 107(3):425-9. · 4.24 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study assessed the duration of pre-operative fasting in children and its impact on the subjective feeling of hunger and thirst prior to elective outpatient anesthesia. Pediatric fasting guidelines are designed to reduce the risk of pulmonary aspiration of gastric contents during general anesthesia, and a fasting regimen of 6-8 h for solids, 4 h for breast milk, and 2 h for clear fluids is commonly used. Anecdotal evidence suggests that fasting times are often excessive. A total of 1350 consecutive healthy children aged <16 (median 7.7, range 2-16) presenting for elective dental treatment under general anesthesia were enrolled in this prospective study. On hospital arrival, all children were asked when they last ate or drank and to rate their degree of hunger and thirst. The median (range) fasting times were 12:05 (00:45-21:50) hours and 07:57 (00:05-20:50) hours for solids and fluids, respectively. The majority of children were very hungry or starving (756/1350=56%), but less than a third of all children were very thirsty (361/1350=27%). Duration of solid food fast and severity of hunger correlated for patients fasted from before midnight (r=0.92) but not for food after midnight. No correlation was found for fluid intake and perception of thirst. This study shows that children presenting for elective outpatient surgery are suffering from a considerable amount of pre-operative discomfort because of excessive fasting. Strategies to guarantee minimal fasting at hospital admission are urgently needed.
    Pediatric Anesthesia 04/2011; 21(9):964-8. · 2.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the effect of fasting times for clear fluids and solids/non-clear fluids on gastric content volume using magnetic resonance imaging (MRI). Pediatric patients undergoing diagnostic MRI under deep propofol sedation, with the stomach located within the area of diagnostic study, were included in this clinical observational study. According to standard institutional guidelines, children were allowed to eat/drink until 4 h and to drink clear fluids until 2 h before scheduled induction time of anesthesia. Gastric content volume per kg body weight (GCV(w)) was determined using MRI and compared with actual fasting times prior to induction. Overall 68 patients aged from 0.3 to 19.6 (2.8) years were investigated. Fasting time for clear fluids ranged from 1.1 to 15.5 (5.5) h, for non-clear fluids/solids from 4.0 to 20.2 (6.7) h. GCV(w) ranged from 0.2 to 6.3 (0.75) ml·kg(-1) and showed no significant negative correlation to fasting times for clear fluids (r = -0.07, P = 0.60) and non-clear fluids/solids (r = -0.08, P = 0.51). Based on this preliminary data, GCV(w) showed considerable variation but did not correlate with fasting times in children and adolescent patients. Recommended fasting times were often exceeded.
    Pediatric Anesthesia 03/2011; 21(6):685-90. · 2.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study compares the accuracy of a new continuous venous oxygenation monitoring system (PediaSat Oximetry Catheter) with laboratory blood oximetry in paediatric surgical patients. Children and adolescents undergoing cardiac, orthopaedic or craniofacial surgery with major blood loss were included. A 4.5 Fr two-lumen or 5.5 Fr three-lumen central venous oximetry catheter (SPediaSatcvO2) was inserted preoperatively into the superior vena cava. After in-vivo calibration of the PediaSat system, repeated blood samples were obtained from the distal port of the venous catheter and oximetrically analysed for haemoglobin and central venous oxygen saturation (SCO-OXcvO2). Central venous oxygen saturation values measured by the PediaSat (SPediaSatcvO2) were compared with co-oximetry (SCO-OXcvO2) values from the simultaneously taken blood samples by Bland-Altman and simple regression analyses. Overall, 142 data pairs from 27 patients, aged from 0.6 to 19.0 years (median 5.3 years) were analysed. SPediaSatcvO2 and SCO-OXcvO2 values ranged from 57 to 98% and from 57.1 to 95.8%, respectively. Correlation between SPediaSatcvO2 and SCO-OXcvO2 was poor with r equal to 0.28 (P < 0.0001). SPediaSatcvO2 overestimated SCO-OXcvO2 (mean bias +2.6%), but limits of agreement (+/-2 SD of bias) were unacceptably high (-14.4/+19.6%). Sensitivity and specificity of SPediaSatcvO2 to indicate a fall or rise of SCO-OXcvO2 between two subsequent measurements were only 0.42 and 0.24, respectively. In paediatric and adolescent patients undergoing major surgery, the PediaSat system did not reliably reflect SCO-OXcvO2 values and cannot replace repeated invasive ScvO2 assessments in the clinically relevant range of ScvO2.
    European Journal of Anaesthesiology 08/2010; 27(8):720-5. · 2.79 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Intrathecal opioids have been shown to be safe and effective for postoperative analgesia in healthy children for spinal surgery. The aim of this study was to evaluate the applicability of intrathecal opioids in severely handicapped children scheduled for spinal surgery. With hospital ethical committee approval, patients with physical states III and IV of the ASA classification requiring spinal surgery were retrospectively studied. In addition to inhalational anesthesia with sevoflurane or intravenous anesthesia using propofol, morphine 20 microg/kgBW and sufentanil 1.5 microg/kgBW were administered intrathecally before surgery. After surgery an infusion of nalbuphine was started. Need for additional intraoperative and postoperative analgesics, time of extubation, postoperative pain scores and p(a)CO2 values as well as adverse effects were recorded. A total of 28 patients aged from 2.8 to 18.5 years (median 11.6 years) were studied. Immediate tracheal extubation in the operating room was possible in 17 patients and for 11 patients delayed extubation was elected. All patients were extubated within 24 h except for 1 patient who received massive postoperative transfusions. In 26 out of 28 patients (93%) the combination of intrathecal opioids with postoperative nalbuphine provided adequate analgesia. Observed side effects were post-operative nausea and vomiting (PONV), pruritus and moderate hypoventilation. In two patients a change to intravenous morphine therapy was necessary. The use of intrathecal opioids for perioperative pain control from spinal fusion in severely handicapped children is feasible. Intrathecal opioids provide adequate postoperative analgesia and allow early extubation without persisting relevant respiratory compromise in most of these patients.
    Der Anaesthesist 07/2010; 59(7):614-20. · 0.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study aims to evaluate sevoflurane and anaesthetic gas consumption using uncuffed vs. cuffed endotracheal tubes (ETT) in paediatric surgical patients. Uncuffed or cuffed ETT were used in paediatric patients (newborn to 5 years) undergoing elective surgery in a randomized order. Duration of assessment, lowest possible fresh gas flow (minimal allowed FGF: 0.5 l/min) and sevoflurane concentrations used were recorded. Consumption and costs for sevoflurane and medical gases were calculated. Seventy children (35 uncuffed ETT/35 cuffed ETT), aged 1.73 (0.01-4.80) years, were enrolled. No significant differences in patient characteristics, study period and sevoflurane concentrations used were found between the two groups. Lowest possible FGF was significantly lower in the cuffed ETT group [1.0 (0.5-1.0) l/min] than in the uncuffed ETT group [2.0 (0.5-4.3) l/min], P<0.001. Sevoflurane consumption per patient was 16.1 (6.4-82.8) ml in the uncuffed ETT group and 6.2 (1.1-14.9) ml in the cuffed ETT group, P=0.003. Medical gas consumption was 129 (53-552) l in the uncuffed ETT group vs. 46 (9-149) l in the cuffed ETT group, P<0.001. The total costs for sevoflurane and medical gases were 13.4 (6.0-67.3)euro/patient in the uncuffed ETT group and 5.2 (1.0-12.5)euro/patient in the cuffed ETT group, P<0.001. The use of cuffed ETT in children significantly reduced the costs of sevoflurane and medical gas consumption during anaesthesia. Increased costs for cuffed compared with uncuffed ETT were completely compensated by a reduction in sevoflurane and medical gas consumption.
    Acta Anaesthesiologica Scandinavica 01/2010; 54(7):855-858. · 2.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Quantification of ventricular volume by steady state free precession (SSFP) cardiovascular magnetic resonance is accurate and reproducible. Normal values exist for adults, but are lacking for children.We sought to establish normal values for left and right ventricular volumes, mass and function in healthy children by using SSFP. Fifty children (27 females, 23 males) without cardiovascular disease were evaluated. Median age was 11 years (range 7 months - 18 years), weight 35 kg (range 7-77 kg), height 146 cm (range 66-181 cm). Thirty-six examinations were performed with breath holding, 14 in freely breathing sedated children.Ventricular volumes and mass were measured in the end systolic and end diastolic phase on SSFP cine images acquired in a short axis plane as a stack of 12 contiguous slices covering full length of both ventricles. Regression analysis showed an exponential relationship between body surface area (BSA) and ventricular volumes and mass (normal value = a*BSAb). Normative curves for males and females are presented in relation to BSA for the end-diastolic volume, end-systolic volume and mass of both ventricles. Intra- and interobserver variability of the measurements was within the limits of 2% and 7% respectively, except for right ventricular mass (10%). The exponential equation for calculation of normal values for each ventricular parameter and graphical display of normative curves for data acquired in healthy children by SSFP cardiovascular magnetic resonance are provided.
    Journal of Cardiovascular Magnetic Resonance 07/2009; 11:19. · 4.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the noninvasive electrical velocimetry (Aesculon) monitor for cardiac output (CO) by subxiphoidal Doppler flow measurement in children. CO was determined at the end of diagnostic or interventional cardiac catheterization for congenital heart defects. Standard ECG surface electrodes were attached in a vertical direction to the patients' left middle and lower neck, and lower thorax at the level of the heart and xiphoid process. Aesculon CO data were compared with a simultaneously measured CO by the subxiphoidal Doppler flow measurement technique. For each patient, measurements were repeated three times within 5 min. Whitney U-test, simple regression and Bland-Altman analysis were performed to compare CO values obtained by the two techniques. Data are given as range (median). A total of 36 children aged 5.7 (0.5-16.0) years were investigated. CO values obtained by Aesculon monitor [0.55-5.58 (2.62) l min] and subxiphoidal Doppler flow measurements [0.62-6.27 (3.05) l min] differed significantly between both methods (P = 0.04). Simple regression analysis revealed moderate correlation between CO values obtained from the two techniques (r = 0.5544, P < 0.001). Bias between the two methods was 0.31 l min with a precision of 1.92 l min. We conclude that electrical velocimetry using the Aesculon monitor does not reliably reflect absolute CO values as compared with subxiphoidal Doppler flow measurement.
    European Journal of Anaesthesiology 03/2009; 26(5):412-5. · 2.79 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The safe use of cuffed tracheal tubes for children necessitates a cuff pressure limitation at 20-25 cmH2O. The aim of the study was to evaluate the reliability and benefit of a new cuff pressure release valve (opening pressure 20 cmH2O) for children intubated with a cuffed tracheal tube. In a prospective, observational trial cuff pressure was recorded in paediatric and adolescent patients intubated with a cuffed tracheal tube during sevoflurane/nitrous oxide anaesthesia. The cuff pressure release valve was interposed between the cuff manometer and the pilot balloon. In 25 patients measurements were started at the initial opening pressure (group A) and in a further 25 patients measurements were started at the minimal sealing cuff pressure (group B). A total of 50 patients, aged from 0.4 to 17.8 years (median 7.4 years) were enrolled in the study. The opening pressure measured (group A) was 19.7+/-0.8 cmH(2)O and the cuff sealing pressure (group B) was 11.7+/-2.9 cmH2O (range 6-16 cmH2O). Mean cuff pressure values in group A were 20.4+/-1.6 cmH2O and 16.5+/-3.3 cmH2O in group B. In one patient (group A) the cuff pressure exceeded 25 cmH2O and was manually decreased to 20 cmH2O. In total, 24 filling procedures (group A 14; group B 10) were required during 103.1 h of investigation because of cuff pressure drop and audible air leakage, mainly caused by cuff pressure increases and consequent releases during patient positioning. Our data demonstrate that the tested cuff pressure release valve was useful and reliable to limit cuff pressure in tracheal intubated children and adolescents within an acceptable pressure range.
    Der Anaesthesist 02/2009; 58(1):16-23. · 0.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate whether regional cerebral oxygenation (rSO(2)) by near-infrared spectroscopy correlates with central venous (SvO(2)) or internal jugular (SjO(2)) oxygen saturation, and whether changes over time (Delta) in rSO(2) (DeltarSO(2)) predict changes in SvO(2) (DeltaSvO(2)) and SjO(2) (DeltaSjO(2)). The rSO(2) values were measured using the INVOS 5100 cerebral oximeter in children undergoing interventional cardiac catheterization and were compared with the oxygen saturation of analysed central venous and internal jugular blood samples. Changes over time (Delta) were calculated as the difference between the values before and after catheter intervention for rSO(2).(DeltarSO(2)), SvO(2).(DeltaSvO(2)) and SjO(2).(DeltaSjO(2)). Simple regression and Bland-Altman analysis were performed. Data are presented as median (range). Sixty patients aged 4.3 (0.2-16.0) years were investigated. A closer correlation was found between rSO(2) and SvO(2) (r=0.728, P<0.0001) than between rSO(2) and SjO(2) (r=0.665, P<0.0001). The bias between rSO(2) and SvO(2).(SjO(2)) was 0.17% (-0.60%), with limits of agreement from -15.5% to 15. 9% (-18.6-17.4%). The sensitivity/specificity for DeltarSO(2) to indicate a fall in SvO(2) or in SjO(2) was 70.3%/65.2% and 68.6%/60.0%, respectively. Neither absolute values nor changes in rSO(2) using the INVOS 5100 allowed reliable estimation of SvO(2) or SjO(2) and their trends.
    Acta Anaesthesiologica Scandinavica 12/2008; 52(10):1370-4. · 2.36 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Our objective was to compare calculated (LaFarge) with measured oxygen consumption (VO(2)) using the AS/3 TM Compact Airway Module M-CAiOVX (Datex-Ohmeda, Helsinki, Finland; AS/3 TM) in children without cardiac shunts in a prospective, observational study. VO(2) was determined at the end of the routine diagnostic and/or interventional catheterization. VO(2 )was calculated according to the formula of LaFarge and Miettinen for each child and compared with the measured VO(2). Data were compared using simple regression and Bland Altman analysis. Fifty-two children aged from 0.5 to 16 years (median, 6.9 years) and weighing 3.4 to 59.4 kg (median, 22.9 kg) were investigated. Calculated VO(2 )values ranged from 59.0 to 230.8 ml/min, and measured VO(2) values from 62.7 to 282.2 ml/min. Comparison of calculated versus measured VO(2) values revealed a significant correlation (r = 0.90, p < 0.0001). Bias and precision were 8.9 and 48.3 ml/min, respectively (95% limits of agreement: -39.4 to 57.2 ml/min). Comparison of calculated VO(2) in children older than 3 years (n = 41), as restricted to the formula, with measured VO(2), revealed a slightly reduced correlation (r = 0.86, p < 0.0001). Bias and precision were 10.0 and 52.5 ml/min, respectively (95% limits of agreement: -42.4 to 62.5 ml/min). We conclude that calculation of VO(2) by the LaFarge formula does not provide reliable values compared to measured values. In clinical routine, measured rather than calculated VO(2) values should be used for the estimation of cardiac output and related variables.
    Pediatric Cardiology 07/2008; 29(6):1054-8. · 1.20 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To compare the assessment of cardiac output (CO) in children using the noninvasive Ultrasound Cardiac Output Monitor (USCOM) with the invasive pulmonary artery catheter (PAC) thermodilution cardiac output measurement. Prospective observational study in a tertiary center for pediatric cardiology of a university children's hospital. Twenty-four pediatric patients with congenital heart disease without shunt undergoing cardiac catheterization under general anesthesia. CO was measured by USCOM using a suprasternal CO Doppler probe in children undergoing cardiac catheterization. USCOM data were compared to CO simultaneously measured by PAC thermodilution technique. Measurements were repeated three times within 5 min in each patient. A mean percentage error not exceeding 30% was defined as indicating clinical useful reliability of the USCOM. CO values measured by PAC ranged from 1.3 to 5.3 l/min (median 3.6 l/min). Bias and precision were -0.13 and 1.34 l/min, respectively. The mean percentage error of CO measurement by the USCOM compared to PAC thermodilution technique was 36.4% for USCOM. Our preliminary data demonstrate that cardiac output measurement in children using the USCOM does not reliably represent absolute CO values as compared to PAC thermodilution. Further studies must evaluate the impact of incorporating effective aortic valve diameters on CO measurement using the USCOM.
    Intensive Care Medicine 07/2008; 34(6):1060-4. · 5.54 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The minimally invasive CardioQP oesophageal Doppler probe estimates cardiac output by measuring blood flow velocity in the descending aorta. Individual variables to enter are patient's age, weight and height. We measured cardiac output simultaneously with CardioQP and pulmonary artery catheter thermodilution techniques during heart catheterisation in 40 paediatric patients with congenital heart defects. Median [range] age was 8.2 years [0.5-16.7 years], cardiac output values measured by thermodilution and CardioQP were 3.6 l.min(-1) [1.2-7.1 l.min(-1)] and 3.0 l.min(-1) [0.7-6.7 l.min(-1)], respectively. These values showed only moderate correlation (r = 0.809; p < 0.0001). Bias and precision were 0.66 l.min(-1) and 1.79 l.min(-1) (95% limits of agreement: -1.13 to +2.45 l.min(-1)). Based on our preliminary experience, cardiac output values measured by CardioQP in children do not reliably represent cardiac output values compared with the thermodilution technique. We suggest measurement of individual aortic diameter to improve performance of the CardioQP.
    Anaesthesia 06/2008; 63(8):851-5. · 3.49 Impact Factor

Publication Stats

299 Citations
79.82 Total Impact Points


  • 2007–2013
    • University Children's Hospital Basel
      Bâle, Basel-City, Switzerland
  • 2008–2012
    • University of Zurich
      Zürich, Zurich, Switzerland
  • 2011
    • NHS Grampian
      Aberdeen, Scotland, United Kingdom
  • 2010
    • University of Innsbruck
      Innsbruck, Tyrol, Austria