Between hope and disillusionment: ECMO seen through the lens of nurses working in a neonatal and paediatric intensive care unit.

BACKGROUND: Using extracorporeal membrane oxygenation (ECMO) in paediatric and neonatal intensive care units (PICU/NICU) creates ethical challenges and carries a high risk for moral distress, burn out and team conflicts. AIM: The study aimed to gain a more comprehensive understanding of the underlying factors affecting moral distress when using ECMO for infants and children by examining the attitudes of ECMO nurses. METHODS: Four focus groups discussions were conducted with 21 critical care nurses working in a Swiss University Children's Hospital. Purposive sampling was adopted to identify research participants. The data were analysed using reflexive thematic analysis. RESULTS: Unlike "miracle machine" stories in online media reports, specialized nurses working in PICU/NICU expressed both their hopes and fears towards this technology. Their accounts also contained references to events and factors that triggered experiences of moral distress: the unspeakable nature of the death of a child or infant; the seemingly lack of honest and transparent communication with parents; the apparent loss of situational awareness among doctors; the perceived lack of recognition for the role of nurses and the variability in end-of-life decision-making; the length of time it takes doctors to take important treatment decisions; and the resource intensity of an ECMO treatment. CONCLUSION: The creation of a multidisciplinary moral community with transparent information among all involved health care professionals and the definition of clear treatment goals as well as the implementation of paediatric palliative care for all paediatric ECMO patients should become a priority if we want to alleviate situations of moral distress. RELEVANCE FOR CLINICAL PRACTICE: The creation of a multidisciplinary moral community, clear treatment goals and the implementation of palliative care for all paediatric ECMO patients are crucial to alleviate situations of moral distress for nurses, and thus to improve provider well-being and the quality of patient care in PICU/NICU.

Pressure-adjusted venting eliminates start-up delays and compensates for vertical position of syringe infusion pumps used for microinfusion.

Microinfusions are commonly used for the administration of catecholamines, but start-up delays pose a problem for reliable and timely drug delivery. Recent findings show that venting of the syringe infusion pump with draining of fluid to ambient pressure before directing the flow towards the central venous catheter does not counteract start-up delays. With the aim to reduce start-up delays, this study compared fluid delivery during start-up of syringe infusion pumps without venting, with ambient pressure venting, and with central venous pressure (CVP)-adjusted venting. Start-up fluid delivery from syringe pumps using a microinfusion of 1 mL/h was assessed by means of liquid flow measurement at 10, 60, 180 and 360 s after opening the stopcock and starting the pump. Assessments were performed using no venting, ambient pressure venting or CVP-adjusted venting, with the pump placed either at zero, - 43 cm or + 43 cm level and exposed to a simulated CVP of 10 mmHg. Measured fluid delivery was closest to the calculated fluid delivery for CVP-adjusted venting (87% to 100% at the different timepoints). The largest deviations were found for ambient pressure venting (- 1151% to + 82%). At 360 s after start-up 72% to 92% of expected fluid volumes were delivered without venting, 46% to 82% with ambient pressure venting and 96% to 99% with CVP-adjusted venting. CVP-adjusted venting demonstrated consistent results across vertical pump placements (p = 0.485), whereas the other methods had significant variances (p < 0.001 for both). In conclusion, CVP-adjusted venting effectively eliminates imprecise drug delivery and start-up delays when using microinfusions.

Evaluation of the venting principle to reduce start-up delays in syringe infusion pumps used for microinfusions.

Start-up delays of syringe pump assemblies can impede the timely commencement of an effective drug therapy when using microinfusions in hemodynamically unstable patients. The application of the venting principle has been proposed to eliminate start-up delays in syringe pump assemblies. However, effectively delivered infusion volumes using this strategy have so far not been measured. This invitro study used two experimental setups to measure the effect of the venting principle compared to a standard non-venting approach on delivered start-up infusion volumes at various timepoints, backflow volumes, flow inversion and zero drug delivery times by means of liquid flow measurements at flow rates of 0.5, 1.0 and 2.0 mL/h. Measured delivered initial start-up volumes were negative with all flow rates in the vented and non-vented setup. Maximum backflow volumes were 1.8 [95% CI 1.6 to 2.3] times larger in the vented setup compared to the non-vented setup (p < 0.0001). Conversely, times until flow inversion were 1.5 [95% CI 1.1 to 2.9] times shorter in the vented setup (p < 0.002). This led to comparable zero drug delivery times between the two setups (p = 0.294). Start-up times as defined by the achievement of at least 90% of steady state flow rate were achieved faster with the vented setup (p < 0.0001), but this was counteracted by the increased backflow volumes. The application of the venting principle to the start-up of microinfusions does not improve the timely delivery of drugs to the patient since the faster start-up times are counteracted by higher backflow volumes when opening the three-way stopcock.

Congenital syphilis in Switzerland: a retrospective cohort study, 2010 to 2019.

AIMS OF THE STUDY: We previously reported a re-emergence of syphilis from 2006 to 2009 with detection of congenital syphilis in Switzerland. This study aimed to reassess the incidence of children exposed to maternal syphilis during pregnancy and congenital syphilis in a following 10-year period in the canton of Zurich, the most populous canton in Switzerland with the highest incidences of syphilis. METHODS: Children were identified both by reviewing medical records at the four major neonatal and paediatric hospitals providing acute care in the canton of Zurich and by the serological database of the syphilis reference laboratory. Inclusion criteria for children were (a) date of birth in the period 2010-2019, (b) place of birth in the canton of Zurich, (c) evaluation for syphilis due to positive syphilis pregnancy screening and (d) age <1 year at diagnosis. Results were compared with epidemiological data provided by the Federal Office of Public Health (FOPH). RESULTS: We identified and evaluated 17 children after potential exposure to maternal syphilis. Residual antibodies of a past infection were found in 11 mothers. Six children were identified as having had real exposure to asymptomatic maternal syphilis. From an epidemiological perspective, the distribution of the cases followed a similar pattern as confirmed syphilis cases in women of childbearing age reported to the FOPH. No cases of congenital syphilis were observed. CONCLUSIONS: In contrast to the rise in syphilis infections, this study identified no cases of congenital syphilis in the canton of Zurich, Switzerland, in the period 2010-2019. Syphilis pregnancy screening may have prevented congenital syphilis by diagnosing and allowing adequate treatment of asymptomatic maternal syphilis.

Effect of central venous pressure on fluid delivery during start-up of syringe infusion pumps for microinfusion.

BACKGROUND: Intravenous administration of highly concentrated and potent drugs at low flow rates is common practice, particularly in critically ill children. Drug delivery during infusion start-up can be considerably delayed by intrinsic factors of syringe infusion pump assemblies. The impact of central venous pressures on the course of start-up fluid delivery of such microinfusions remains unknown. METHODS: Infusion volumes delivered after activation of the start button in a conventional 50 mL syringe infusion pump assembly equilibrated (representing classical in vitro testing) and not equilibrated (representing real clinical conditions) to central venous pressure levels of 0, 10 and 20 mmHg at a set infusion flow rate of 1 mL/h were measured using a fluidic flow sensor. RESULTS: The experimental setup mimicking real life conditions demonstrated considerable differences in fluid delivery during pump start-up depending on central venous pressure. A central venous pressure of 0 mmHg resulted in massive fluid delivery at infusion start-up, while central venous pressure levels of 10 and 20 mmHg resulted in retrograde flows with related mean (95% CI) zero-drug delivery times of 3.22 (2.98-3.46) min and 4.51 (4.33-4.69) min, respectively (p < .0001). CONCLUSION: Depending on central venous pressure level, connection and starting a new syringe pump can result in significant antegrade or retrograde fluid volumes. In clinical practice, this can lead to hemodynamic instability and hence requires clinical alertness. Further research and methods to improve start-up performance in syringe infusion pump systems are desirable.

Copeptin Release in Arterial Hypotension and Its Association with Severity of Disease in Critically Ill Children.

Low copeptin levels may indicate inadequate arginine-vasopressin release promoting arterial hypotension, whereas high copeptin concentrations may reflect disease severity. This single-center prospective non-randomized clinical trial analyzed the course of blood copeptin in critically ill normo- and hypotensive children and its association with disease severity. In 164 patients (median age 0.5 years (interquartile range 0.1, 2.9)), the mean copeptin concentration at baseline was 43.5 pmol/L. Though not significantly different after 61 h (primary outcome, mean individual change: −12%, p = 0.36, paired t-test), we detected 1.47-fold higher copeptin concentrations during arterial hypotension when compared to normotension (mixed-effect ANOVA, p = 0.01). In total, 8 out of 34 patients (23.5%) with low copeptin concentrations <10 pmol/L were hypotensive. Copeptin was highest in the adjusted mixed-effect regression analysis within the first day (+20% at 14 h) and decreased significantly at 108 h (−27%) compared to baseline (p = 0.002). Moreover, we found a significant association with vasopressor-inotrope treatment intensity, infancy (1−12 months) and cardiopulmonary bypass (all p ≤ 0.001). In conclusion, high copeptin values were associated with arterial hypotension and severity of disease in critically ill children. This study does not support the hypothesis that low copeptin values might be indicative of arginine-vasopressin deficiency.

Lung-borne systemic inflammation in mechanically ventilated infant rats due to high PEEP, oxygen, and hypocapnia.

BACKGROUND: Intensive care practice calls for ventilator adjustments due to fast-changing clinical conditions in ventilated critically ill children. These adaptations include positive end-expiratory pressure (PEEP), fraction of inspired oxygen (FiO2), and respiratory rate (RR). It is unclear which alterations in ventilator settings trigger a significant systemic inflammatory response. METHODS: Fourteen-day old Wistar rat pups were randomized to the following groups: (a) "control" with tidal volume ~8 mL/kg, PEEP 5 cmH2O, FiO2 0.4, RR 90 min-1, (b) "PEEP 1", (c) "PEEP 9" (d) "FiO2 0.21", (e) "FiO2 1.0", (f) "hypocapnia" with RR of 180 min-1, and (g) "hypercapnia" with RR of 60 min-1. Following 120 min of mechanical ventilation, plasma for inflammatory biomarker analyses was obtained by direct cardiac puncture at the end of the experiment. RESULTS: Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were driven by FiO2 0.4 and 1.0 (P=0.02, P<0.01, respectively), tissue plasminogen activator inhibitor type-1 (tPAI-1) was increased by high PEEP (9 cmH2O, P<0.05) and hypocapnia (P<0.05), and TNF-α was significantly lower in hypercapnia (P<0.01). Tissue inhibitor of metalloproteinase-1 (TIMP-1), cytokine-induced neutrophil chemoattractant 1 (CINC-1), connective tissue growth factor (CTGF), and monocyte chemoattractant protein-1 (MCP-1) remained unaffected. CONCLUSION: Alterations of PEEP, FiO2, and respiratory frequency induced a significant systemic inflammatory response in plasma of infant rats. These findings underscore the importance of lung-protective ventilation strategies. However, future studies are needed to clarify whether ventilation induced systemic inflammation in animal models is pathophysiologically relevant to human infants.

Macitentan attenuates cardiovascular remodelling in infant rats with chronic lung disease.

BACKGROUND: Cardiovascular impairment contributes to increased mortality in preterm infants with chronic lung disease. Macitentan, an endothelin-1 receptor antagonist, has the potential to attenuate pulmonary and cardiovascular remodelling. METHODS: In a prospective randomized placebo-controlled intervention trial, Sprague-Dawley rats were exposed to 0.21 or 1.0 fraction of inspired oxygen (FiO2) for 19 postnatal days. Rats were treated via gavage with placebo or macitentan from days of life 5 to 19. Alveoli, pulmonary vessels, α-smooth muscle actin content in pulmonary arterioles, size of cardiomyocytes, right to left ventricular wall diameter ratio, and endothelin-1 plasma concentrations were assessed. RESULTS: FiO2 1.0 induced typical features of chronic lung disease with significant alveolar enlargement (p = 0.012), alveolar (p = 0.048) and pulmonary vessel rarefaction (p = 0.024), higher α-smooth muscle actin content in pulmonary arterioles (p = 0.009), higher right to left ventricular wall diameter ratio (p = 0.02), and larger cardiomyocyte cross-sectional area (p < 0.001). Macitentan treatment significantly increased pulmonary vessel count (p = 0.004) and decreased right to left ventricular wall diameter ratios (p = 0.002). Endothelin-1 plasma concentrations were higher compared to placebo (p = 0.015). Alveolar number and size, α-smooth muscle actin, and the cardiomyocyte cross-sectional area remained unchanged (all p > 0.05). CONCLUSION: The endothelin-1 receptor antagonist macitentan attenuated cardiovascular remodelling in an infant rat model for preterm chronic lung disease. This study underscores the potential of macitentan to reduce cardiovascular morbidity in preterm infants with chronic lung disease.

Strain-specific differences in lung tissue viscoelasticity of mechanically ventilated infant Sprague-Dawley and Wistar rats.

Rats are often used in ventilator-induced lung injury (VILI) models. However, strain-specific susceptibility for VILI has not been elucidated yet. The aim of this study was to demonstrate strain-specific differences in VILI in infant Sprague-Dawley and Wistar rats. VILI was compared in 2-wk-old pups after 8 h of protective or injurious ventilation. Pups were ventilated with tidal volumes (VT) of ∼7 mL/kg and positive end-expiratory pressures (PEEP) of 6 cmH2O (VT7 PEEP6) or with VT of ∼21 mL/kg and PEEP 2 cmH2O (VT21 PEEP2). Interleukin-6, macrophage inflammatory protein-2 (MIP-2), inflammatory cells, and albumin in bronchoalveolar lavage fluid (BALF); histology; and low-frequency forced oscillation technique (LFOT) and pressure-volume (PV) maneuvers were assessed. Alveolar macrophages, neutrophils, and MIP-2 derived from BALF revealed more pronounced VILI after VT21 PEEP2 in both strains. LFOT and PV analyses demonstrated rat strain-specific differences both at baseline and particularly in response to VT21 PEEP2 ventilation. Sprague-Dawley rats showed higher airway and tissue resistance and elastance values with no difference in hysteresivity between ventilation strategies. Wister rats challenged by VT21 PEEP2 experienced significantly more energy dissipation when compared with VT7 PEEP6 ventilation. In conclusion, both rat strains are useful for VILI models. The degree of VILI severity depends on ventilation strategy and selected strain. However, fundamental and time-dependent differences in respiratory system mechanics exist and reflect different lung tissue viscoelasticity. Hence, strain-specific characteristics of the respiratory system need to be considered when planning and interpreting VILI studies with infant rats.

Impact of high tidal volume ventilation on surfactant metabolism and lung injury in infant rats.

The poorly understood tolerance toward high tidal volume (VT) ventilation observed in critically ill children and age-equivalent animal models may be explained by surfactant homeostasis. The aim of our prospective animal study was to test whether high VT with adequate positive end-expiratory pressure (PEEP) is associated with surfactant de novo synthesis and secretion, leading to improved lung function, and whether extreme mechanical ventilation affects intracellular lamellar body formation and exocytosis. Rats (14 days old) were allocated to five groups: nonventilated controls, PEEP 5 cmH2O with VT of 8, 16, and 24 mL/kg, and PEEP 1 cmH2O with VT 24 mL/kg. Following 6 h of ventilation, lung function, surfactant proteins and phospholipids, and lamellar bodies were assessed by forced oscillation technique, quantitative real-time polymerase chain reaction, mass spectrometry, immunohistochemistry, and transmission electron microscopy. High VT (24 mL/kg) with PEEP of 5 cmH2O improved respiratory system mechanics and was not associated with lung injury, elevated surfactant protein expression, or surfactant phospholipid content. Extreme ventilation with VT 24 mL/kg and PEEP 1 cmH2O produced a mild inflammatory response and correlated with higher surfactant phospholipid concentrations in bronchoalveolar lavage fluid without affecting lamellar body count and morphology. Elevated phospholipid concentrations in the potentially most injurious strategy (VT 24 mL/kg, PEEP 1 cmH2O) need further evaluation and might reflect accumulation of biophysically inactive small aggregates. In conclusion, our data confirm the resilience of infant rats toward high VT-induced lung injury and challenge the relevance of surfactant synthesis, storage, and secretion as protective factors.

Evaluation of Incompatible Coadministration of Continuous Intravenous Infusions in a Pediatric/Neonatal Intensive Care Unit.

OBJECTIVES: We aimed to evaluate and quantify incompatible coadministrations of continuous intravenous medication in the daily clinical practice of a PICU/NICU. METHODS: We conducted a retrospective, observational study in the setting of an 18-bed PICU/NICU. All concurrently administered continuous infusions, including blood products and parenteral nutrition, were analyzed for 2 months. Raw electronic data were retrieved and subjected to quality controls. Infusion combinations were classified as compatible, incompatible, no data, or variable according to the internal hospital charts, Trissel's database, and the Swiss summary of product characteristics. For situations with incompatible coadministrations, we assessed alternative distributions of infusions among the currently available lumen. RESULTS: Data for 100 patients were analyzed. Patients were exposed to a mean of 6.9 ± 3.6 individual continuous infusions administered through 3.8 ± 1.8 lumina. Among the 1447 coadministered continuous infusions, we detected 146 incompatible combinations (10%), resulting in 105 individually relevant incompatible situations. Furthermore, 185 combinations (13%) were not covered by internal compatibility charts, and for 207 combinations (15%) no data on compatibility were available. We found that 58% of the incompatible situations could have been avoided by a redistribution of the infusions among the available lumina. CONCLUSIONS: Most infusion combinations in the studied PICU/NICU were compatible and covered by the internal compatibility charts. However, we also identified concurrent administrations of incompatible infusions or for which compatibility data are not available. A significant reduction of coadministrations of incompatible infusions could be achieved through optimal use of available lumina.

Prognostic Evaluation of Mortality after Pediatric Resuscitation Assisted by Extracorporeal Life Support.

To improve survival rates during cardiopulmonary resuscitation (CPR), some patients are put on extracorporeal life support (ECLS) during active resuscitation (ECPR). Our objective was to assess the clinical outcomes after pediatric ECPR in Switzerland and to determine pre-ECPR prognostic factors for mortality. The present study is a retrospective analysis. The study setting included three pediatric intensive care units in Switzerland that use ECPR. All patients (<16 years old) undergoing ECPR from 2008 to 2016 were included in the study. There were no interventions. Data before ECLS initiation and clinical outcomes were collected. An ECPR score was designed to predict mortality, based on variables significantly different between survivors and non-survivors. Fifty-five patients were included, with a median age of 13.5 months. Eighty percent were cardiac patients. The mortality rate was 75%. Mortality was significantly associated with CPR duration ( p = 0.02), last lactate ( p = 0.05), and last pH ( p = 0.01) before ECLS initiation. Based on these three variables, an ECPR score was designed as follows: CPR duration (in minutes): 1 point if < 40; 2 points if ≥ 40; 3 points if ≥ 60; 6 points if ≥ 105. Lactate (in mmol/L): 1 point if < 8; 2 points if ≥ 8; 3 points if ≥ 14; 6 points if ≥ 18. pH: 1 point if > 7.00; 2 points if ≤ 7.00; 3 points if ≤ 6.85; 6 points if ≤ 6.60. The area under the receiver-operating characteristic curve was 0.74. The positive predictive value of a score ≥ 9 was 94%. In our population, a score based on three variables easily available prior to ECLS initiation had good discrimination and could appropriately predict mortality. This score now needs validation in a larger population.

Hyperoxia-induced lung structure-function relation, vessel rarefaction, and cardiac hypertrophy in an infant rat model.

BACKGROUND: Hyperoxia-induced bronchopulmonary dysplasia (BPD) models are essential for better understanding and impacting on long-term pulmonary, cardiovascular, and neurological sequelae of this chronic disease. Only few experimental studies have systematically compared structural alterations with lung function measurements. METHODS: In three separate and consecutive series, Sprague-Dawley infant rats were exposed from day of life (DOL) 1 to 19 to either room air (0.21; controls) or to fractions of inspired oxygen (FiO2) of 0.6, 0.8, and 1.0. Our primary outcome parameters were histopathologic analyses of heart, lungs, and respiratory system mechanics, assessed via image analysis tools and the forced oscillation technique, respectively. RESULTS: Exposure to FiO2 of 0.8 and 1.0 resulted in significantly lower body weights and elevated coefficients of lung tissue damping (G) and elastance (H) when compared with controls. Hysteresivity (η) was lower due to a more pronounced increase of H when compared with G. A positive structure-function relation was demonstrated between H and the lung parenchymal content of α-smooth muscle actin (α-SMA) under hyperoxic conditions. Moreover, histology and morphometric analyses revealed alveolar simplification, fewer pulmonary arterioles, increased α-SMA content in pulmonary vessels, and right heart hypertrophy following hyperoxia. Also, in comparison to controls, hyperoxia resulted in significantly lower plasma levels of vascular endothelial growth factor (VEGF). Lastly, rats in hyperoxia showed hyperactive and a more explorative behaviour. CONCLUSIONS: Our in vivo infant rat model mimics clinical key features of BPD. To the best of our knowledge, this is the first BPD rat model demonstrating an association between lung structure and function. Moreover, we provide additional evidence that infant rats subjected to hyperoxia develop rarefaction of pulmonary vessels, augmented vascular α-SMA, and adaptive cardiac hypertrophy. Thus, our model provides a clinically relevant tool to further investigate diseases related to O2 toxicity and to evaluate novel pharmacological treatment strategies.

Comparison of postoperative chylothorax in infants and children with trisomy 21 and without dysmorphic syndrome: Is there a difference in clinical outcome?

INTRODUCTION: Children with trisomy 21 are prone to postoperative chylothorax, caused by malformation of the lymphatic system, after cardiac surgery. The clinical course of patients diagnosed with postoperative chylothorax and trisomy 21 was compared to that of patients without dysmorphic syndromes. Additionally, differences between the groups in composition, amount, and duration of chyle were analyzed to better understand chylothorax in patients with trisomy 21. MATERIALS AND METHODS: Retrospective cohort study using inpatient clinical databases during a 10-year period. RESULTS: A total of 2255 patients underwent cardiac operations during the period, of whom 160 (7.1%) patients were diagnosed with trisomy 21. Chylothorax developed in 122 children; 89 patients were included in our study. Of 160 trisomy 21 patients, 27 (16.9%) developed postoperative chylothorax compared to 62 (3%) of 2095 patients without dysmorphic syndromes (p = <0.001). Time on ventilation, stay in intensive care, hospital stay, mortality, and composition of chylous effusion did not differ between groups. The rate of thrombosis was significantly lower (p = 0.02) in the trisomy 21 group. CONCLUSION: Children with trisomy 21 and congenital heart disease are more prone to developing chylothorax after heart surgery than those without dysmorphic syndromes. However if they develop this postoperative complication, mortality, chylous composition, time in ICU, and duration of hospital stay is not different to from that of other infants or children with this complication. This is important information for the medical specialists involved and is helpful in counseling parents of children with trisomy 21 undergoing heart surgery. LEVEL OF EVIDENCE: This is a treatment study evidence level III.

Work of breathing for cuffed and uncuffed pediatric endotracheal tubes in an in vitro lung model setting.

BACKGROUND: Over the last decade, cuffed endotracheal tubes are increasingly used in pediatric anesthesia and also in pediatric intensive care. However, the smaller inner diameter of cuffed endotracheal tubes and, implicitly, the increased endotracheal tube resistance is still a matter of debate. AIMS: This in vitro study investigated work of breathing and inspiratory airway pressures in cuffed and uncuffed endotracheal tubes and the impact of pressure support ventilation and automatic tube compensation. METHODS: In 5 simulated neonatal and pediatric lung models, the Active Servo Lung 5000 and an intensive care ventilator were used to quantify the differences in work of breathing under spontaneous breathing (with and without pressure support ventilation and automatic tube compensation) between cuffed and uncuffed endotracheal tubes. Additionally, differences in inspiratory airway pressures, measured either proximal or distal of the endotracheal tube, between cuffed and uncuffed endotracheal tubes under mechanical ventilation were investigated. RESULTS: Work of breathing was overall 10.27% [95% confidence interval 9.01-11.94] higher with cuffed than with uncuffed endotracheal tubes and was dramatically reduced by 34.19% [95% confidence interval 31.61-35.25] with the application of pressure support. Automatic tube compensation almost diminished work of breathing differences between the 2 endotracheal tube types in nearly all pediatric lung models. Peak inspiratory and mean airway pressures measured at the proximal endotracheal tube end revealed significantly higher values in cuffed than in uncuffed endotracheal tubes. However, these differences measured at the distal end of the endotracheal tube became minimal. CONCLUSION: This in vitro study confirmed significant differences in work of breathing and inspiratory pressures between cuffed and uncuffed endotracheal tubes. Work of breathing, however, is almost neutralized by pressure support ventilation with automatic tube compensation and distal inspiratory airway pressures that, from a clinical perspective, are not significantly increased.

Prevention of Low Cardiac Output Syndrome After Pediatric Cardiac Surgery: A Double-Blind Randomized Clinical Pilot Study Comparing Dobutamine and Milrinone.

OBJECTIVES: Dobutamine and milrinone are commonly used after open-heart surgery to prevent or treat low cardiac output syndrome. We sought to compare efficacy and safety of these drugs in pediatric patients. DESIGN: Prospective, single-center, double-blinded, randomized clinical pilot study. SETTING: Tertiary-care university children's hospital postoperative pediatric cardiac ICU. PATIENTS: After written consent, 50 consecutive patients (age, 0.2-14.2 yr; median, 1.2 yr) undergoing open-heart surgery for congenital malformations were included. INTERVENTIONS: After cardiopulmonary bypass, a continuous infusion of either dobutamine or milrinone was administered for the first 36 postoperative hours. Maximum dose: dobutamine 6 µg/kg/min, milrinone 0.75 µg/kg/min. MEASUREMENTS AND MAIN RESULTS: There were no significant differences in demographic data, complexity of surgery, and intraoperative characteristics between the two study groups (dobutamine vs milrinone). Efficacy was defined as need for additional vasoactive support, which did not differ between groups (dobutamine 61% vs milrinone 67%; p = 0.71). Sodium nitroprusside was used more often in the dobutamine group (42% vs 13%; p = 0.019). Systolic blood pressure showed a trend toward higher values in the dobutamine group, whereas both drugs increased heart rate early postoperatively. Echocardiography demonstrated a consistently good cardiac function in both groups. Central venous oxygen saturation, serum lactate levels, urine output, time to chest tube removal, length of mechanical ventilation, ICU, and hospital stay were similar in both groups. Both drugs were well tolerated, no serious adverse events occurred. CONCLUSIONS: Dobutamine and milrinone are safe, well tolerated, and equally effective in prevention of low cardiac output syndrome after pediatric cardiac surgery. The hemodynamic response of the two drugs is comparable. In uncomplicated cases, a trend toward the more cost-saving dobutamine might be anticipated; however, milrinone demonstrated a trend toward higher efficacy in afterload reduction.

Mechanical ventilation strategies alter cardiovascular biomarkers in an infant rat model.

Mechanical ventilation (MV) is routinely used in pediatric general anesthesia and critical care, but may adversely affect the cardiocirculatory system. Biomarkers are increasingly measured to assess cardiovascular status and improve clinical treatment decision-making. As the impact of mechanical ventilation strategies on cardiovascular biomarkers in ventilated infants is largely unknown, we conducted this retrospective study in a healthy in vivo infant rat ventilation model using 14-days old Wistar rats. We hypothesized that 2 h of mechanical ventilation with high and low positive end-expiratory pressure (PEEP), hyperoxemia, hypoxemia, hypercapnia, and hypocapnia would significantly impact B-type natriuretic peptide (BNP), vascular endothelial growth factor (VEGF), and endothelin-1 (ET-1). We found BNP to be driven by both high (9 cmH2 O) and low (1 cmH2 O) PEEP compared to ventilated control animals (P < 0.05). VEGF concentrations were associated with high PEEP, hyperoxemia, hypoxemia, and hypocapnia (P < 0.05), whereas ET-1 levels were changed only in response to hypoxemia (P < 0.05). In conclusion, the mode of mechanical ventilation alters plasma biomarker concentrations. Moreover, BNP and VEGF might serve as surrogate parameters for ventilation induced cardiovascular compromise and lung tissue damage. Furthermore, our data support the hypothesis, that sudden onset of hyperoxemia may trigger a quick VEGF release as a possible cellular survival reflex.

Impact of endotracheal tube shortening on work of breathing in neonatal and pediatric in vitro lung models.

BACKGROUND: Work of breathing accounts for a significant proportion of total oxygen consumption in neonates and infants. Endotracheal tube inner diameter and length significantly affect airflow resistance and thus work of breathing. While endotracheal tube shortening reduces endotracheal tube resistance, the impact on work of breathing in mechanically ventilated neonates and infants remains unknown. AIM: The objective of this in vitro study was to quantify the effect of endotracheal tube shortening on work of breathing in simulated pediatric lung settings. We hypothesized that endotracheal tube shortening significantly reduces work of breathing. METHODS: We used the Active-Servo-Lung 5000 to simulate different clinical scenarios in mechanically ventilated infants and neonates under spontaneous breathing with and without pressure support. Endotracheal tube size, lung resistance, and compliance, as well as respiratory settings such as respiratory rate and tidal volume were weight and age adapted for each lung model. Work of breathing was measured before and after maximal endotracheal tube shortening and the reduction of the daily energy demand calculated. RESULTS: Tube shortening with and without pressure support decreased work of breathing to a maximum of 10.1% and 8.1%, respectively. As a result, the calculated reduction of total daily energy demand by endotracheal tube shortening was between 0.002% and 0.02%. CONCLUSION: In this in vitro lung model, endotracheal tube shortening had minimal effects on work of breathing. Moreover, the calculated percentage reduction of the total daily energy demand after endotracheal tube shortening was minimal.

Cardiac transplantation in a neonate-First case in Switzerland and European overview.

Twenty-four percent of pediatric heart transplantations (pHTx) are carried out in infants. Neonatal heart transplantation is both rarely performed and challenging. We report on a newborn baby girl suffering from cardiac failure due to a huge tumor (24×52 mm) within the free wall of the left ventricle (LV) and subtotal obstruction of the main left bronchus. Following a surgical tumor resection, a Berlin Heart EXCOR left ventricular assist device was implanted as the bridge to the transplantation. In spite of an organ donor/recipient mismatch of >200%, both heart transplantation and the postoperative course were successful. In addition to this case report, the authors also present data from a survey on performed infant and neonatal transplantations in Western Europe. As neonatal heart transplantation is a rare event in Europe, the authors think it is of crucial importance to share this limited experience. We discuss an alternative strategy-namely, palliative surgical correction using the Fontan pathway. The challenges of donor/recipient weight mismatch and the possibilities of overcoming infant donor organ shortage as a postoperative immunosuppressive regimen are discussed as well.