The immediate haemodynamic response to the initiation of extracorporeal membrane oxygenation in a piglet model of infant hypoxic respiratory failure.

There is evidence that haemodynamic fluctuations on extracorporeal membrane oxygenation (ECMO) increase the risk of cerebral damage. We hypothesized that initiation of venovenous (VV) or venoarterial (VA) ECMO itself causes haemodynamic fluctuations and, thus, established an infant animal ECMO model in order to discuss this hypothesis. Five piglets were cannulated using the jugular and femoral veins (VV group) and five using the jugular vein and carotid artery (VA group). All animals were subjected to hypoxic ventilation (FiO2 8%) for 10 min, leading to a PaO2 of < 40 mmHg, and subsequently rescued by ECMO. The heart rate (HR) and mean arterial blood pressure (MAP) were recorded at 5-min intervals; the arterial blood lactate was measured prior to and after 5 and 10 min of hypoxia, as well as 30, 60 and 120 min after initiation of ECMO. The response to initiation of ECMO was similar in the VV and VA groups with regard to HR and lactate, but differed significantly in MAP. HR decreased significantly from 135 +/- 7 to 103 +/- 6 beats/min (p < 0.05) and from 132 +/- 8 to 84 +/- 9 beats/min (p < 0.01) at 5 min (p = NS) after installation; lactate increased from 1.4 +/- 0.1 to 1.8 +/- 0.2 mmol/l (p = NS) and from 1.4 +/- 0.2 to 1.6 +/- 0.5 mmol/l (p = NS) after 30 min (p = NS); MAP decreased from 80 +/- 5 to 63 +/- 3 mmHg (p = NS) and increased from 75 +/- 4 to 84 +/- 3 mmHg (p = NS) at 5 min (p = 0.001), respectively. The initiation of ECMO is associated with haemodynamic fluctuations in both modalities, which differ with regard to blood pressure reaction.

Osteomyelitis at the injection site of adrenalin through an intraosseous needle in a 3-month-old infant.

Intraosseous (IO) puncture is considered for the administration of drugs and fluids when vascular access cannot be achieved rapidly. Adrenaline/epinephrine, adenosine, crystalloids, colloids and blood products can be applied and administered effectively using this route during resuscitation of children. This technique is relatively simple with complications of <1%. These may include tibial fracture, lower extremity compartment syndrome and osteomyelitis. A case is described in which a 3-month-old male infant presented for emergency resuscitation requiring IO infusion utilising both tibial bones. High doses of adrenaline (1:1000; 0.1 mg/kg) were administered in the right tibial epiphysis only after the standard initial concentration (1:10000; 0.01 mg/kg) had minimal effect. A local inflammatory reaction was noted 24 h later in the right tibial region, which developed into cutaneous necrosis, and was eventually resected. Radiologically, no osseous lesion could be demonstrated, however, a bone scintigram revealed osteomyelitis. Upon surgical revision, purulent destruction was evident requiring removal of the epiphysis and part of the metaphysis. Although osteomyelitis is a rare complication which may be caused by sepsis, or contamination during insertion, we speculate that adrenaline in high concentrations may promote the development of osteomyelitis and the drug should be applied cautiously in more diluted concentrations.

Severe respiratory failure following charcoal application in a toddler.

Charcoal has been commonly used for enteral detoxication with few adverse effects. In toddlers charcoal can often be simply applied via a gastric tube. Regurgitation and aspiration is considered a rare event. We report the case of a 19-month-old boy who suffered endobronchial charcoal contamination followed by acute airway obstruction and severe respiratory failure despite a commonly used tube placement verification technique. Immediate intubation, tracheal suctioning, intravenous bronchodilators, and high frequency oscillatory ventilation (HFOV) were used to control hypercarbia and hypoxia. Eventually charcoal removal by bronchoscopy was successful. Chest X-ray investigation did not reflect the true amount of charcoal deposited endobronchially at any time. We conclude that gastric tube application of charcoal in children carries a risk of aspiration. This may lead to life-threatening respiratory failure with the need to provide artificial ventilation and bronchial lavage.

A pulsatile pneumatically driven neonatal extracorporeal membrane oxygenation system using neck vessel cannulas tested with neonatal mock circulation.

In posthypoxic circulatory failure, pulsatility of flow generated by mechanical support devices significantly influences outcome. Pneumatically driven assist devices can create highly pulsatile flow, but need large graft cannulas implanted by thoracotomy in children and neonates. Emergency application is therefore hindered. We conducted an in vitro study using neonatal mock circulation (NMC) to test whether an extracorporeal membrane oxygenation (ECMO) system driven by a commercially available pneumatic assist device also can be operated through commonly used neonatal neck vessel cannulas. Using the pneumatically operated Medos ventricular assist device (VAD) 10 ml ventricle along with the Jostra M8/HEC40 oxygenator/heat exchanger, a neonatal ECMO system was assembled and connected to the NMC by means of commercially available neonatal neck vessel cannulas. Effective ECMO flow, combined circulation flow, and circulation pressures were measured during various working settings (ventricle driving pressures [systolic/diastolic (mbar)]: low: +100/-25, moderate: +200/-50, high: +300/-99) and loading conditions (device working against 0, 50, and 100% native circulation flow). Additionally, maximum possible ECMO flow through various sizes of neonatal ECMO cannulas and resulting pressure gradients were assessed. High pressure settings were necessary to achieve 100 ml/kg/min pulsatile circulation flow in case of zero native circulation. With residual 30% native circulation flow, 100 ml/kg/min pulsatile circulation flow could be established by moderate pressure settings. Low preload or high systemic vascular resistance reduced ECMO flow markedly. We concluded that in the described setting a pneumatically driven neonatal ECMO system could be operated even through commonly used neonatal neck vessel cannulas. It was necessary to accept partial emptying of the artificial ventricle and tapering of driving pressures with increasing native circulation.

Neonatal and pediatric extracorporeal membrane oxygenation using nonocclusive blood pumps: the Vienna experience.

Neonatal and pediatric extracorporeal membrane oxygenation (ECMO) is carried out commonly using occlusive blood pumps. Centrifugal pumps provide simple and safe technology for transportation on ECMO. The assistence respiratoire extra corporelle (AREC) system enables single needle venovenous ECMO for infants. We report on our experience with neonatal and pediatric ECMO treatments using nonocclusive blood pumps. One-hundred forty-six ECMO treatments were performed for cardiac, neonatal, and pediatric indications in 54, 19, and 27% of cases. Centrifugal pumps were used in 99, and the AREC system in 42 cases. Hospital mortality was estimated retrospectively and influence of type of pump, type of ECMO belonging to indication group, and lactate at ECMO installation were estimated. Irreversible organ failure leading to ECMO termination was investigated within groups of indications. Survival (recent 50 ECMO treatments) was 80, 70, 43, and 30% after meconium aspiration syndrome, acute respiratory distress syndrome, cardiac surgery, and prolonged resuscitation. Lactate exceeding 100 mg/dl at ECMO installation predicted significantly worse outcome. Cerebral damage was the main reason for ECMO termination in all but persistent circulatory failure in the cardiac group. Myocardial recovery resulted in all except 2 cardiac cases. Nonocclusive blood pumps can be used safely in neonatal and pediatric ECMO. Early installation may improve outcome markedly. In cardiac cases results of surgery should be thoroughly investigated on the table before ECMO installation to prevent hopeless ECMO treatments.

Permissive hypoxemia permitted postoperative weaning from artificial ventilation after repair of pulmonary atresia.

Survival after corrective surgery of pulmonary atresia was associated with low right ventricular pressure, indicating normal pulmonary vascular resistance. Therefore increased fractional inspiratory oxygen concentration, inhaled nitric oxide and intravenous prostacyclin were considered to be effective measures during postoperative intensive care. In a 20-year-old female, conduit repair and unifocalisation of pulmonary atresia with ventricular septal defect and systemic to pulmonary arterial collaterals were performed despite preexisting one-sided pulmonary hypertension. During the following postoperative period, normal arterial oxygen saturation aimed at by means of a high fractional inspiratory oxygen concentration, resulted in persistent pulmonary oedema despite fluid restriction. After several trials of weaning from artificial ventilation, permissive hypoxemia was eventually successful.

Intravenous prostacyclin mitigates inhaled nitric oxide rebound effect: A case control study.

Although extracorporeal membrane oxygenation (ECMO) improves oxygenation, pulmonary vascular resistance may be increased due to endothelial function impairment. Inhaled nitric oxide (iNO) is increasingly used for treatment of pulmonary hypertension after surgical repair of congenital heart defects, with or without ECMO. One of the main complications of its application is deterioration of oxygenation following withdrawal of iNO. To test whether intravenous prostacyclin applied prior to and during iNO withdrawal can mitigate this rebound effect, we conducted a retrospective case control study. The rebound effect was defined as a 5% decrease of oxygenation saturation within 4 h after iNO withdrawal. Twelve children suffering from pulmonary hypertension (2 after ECMO) and treated with iNO received 10 ng/kg/min prostacyclin intravenously 24 h prior to iNO withdrawal (Group 1). Twelve children treated with iNO (3 after ECMO) who received no prostacyclin prior to iNO withdrawal were matched as controls. The rebound effect occurred in 1 out of 12 children in Group 1 and in 8 out of 12 children in Group 2 (p = 0. 0039). We conclude that application of intravenous prostacyclin prior to and during iNO withdrawal may be able to mitigate the rebound effect.

Proposed entry criteria for postoperative cardiac extracorporeal membrane oxygenation after pediatric open heart surgery.

While extracorporeal membrane oxygenation (ECMO) is being used increasingly after pediatric cardiac surgery, criteria are lacking for initiating ECMO after bypass weaning. To develop clinically useful ECMO entry criteria based on parameters readily available, children were examined at postoperative pediatric intensive care unit (PICU) admission. Using hospital mortality as the primary outcome, univariate and multiple logistic regressions were performed to estimate the predictive value of clinical (age, weight, and diagnosis) and laboratory (arterial blood pressure, pH, lactate, creatine kinase, and arterial and central venous oxygen saturation [ScvO2]) variables. Data from 218 children over a 2 year period were analyzed retrospectively. Univariate regression demonstrated that age, weight, diagnosis, blood pressure, venous and arterial saturation, and lactate were significantly associated with postoperative mortality (p < 0.05). In multiple regression, ScvO2 and lactate level were found to be independent predictors and were used in a predictive model (ScvO2 odds ratio: 2.03-828.6, p = 0.016) (lactate odds ratio: 1.58 -4.20, p = 0.0002) (R2 = 0.70). Applying an 80% risk of mortality to establish entry criteria as in neonatal ECMO, PICU admission values of lactate > 70 mg/dl if ScvO2 < 60% or lactate >163 mg/dl if ScvO2 > 60% are proposed to serve as postoperative ECMO entry criteria if bypass weaning has been possible but is followed by low cardiac output.

Issues of pharmacology in pediatric cardiac extracorporeal membrane oxygenation with special reference to analgesia and sedation.

Sufficient analgesia, sedation, and paralysis, if necessary, are cornerstones of extracorporeal membrane oxygenation (ECMO) treatment protocols. However, increased distribution volumes, drug absorption by circuit materials, and impaired drug elimination, as well as alternations of cerebral perfusion and blood brain barrier function, result in the markedly altered pharmacodynamics of applied drugs. Today, narcotics combined with benzodiazepines, sometimes enforced by barbiturates, are commonly used in clinical practice. Paralysis is usually achieved by pancuronium or vecuronium. Although these drugs are used widely, actual efficacy remains uncertain because of the lack of reliable tools to measure pain relief and degree of sedation during ECMO, especially during paralysis. Taking into account the detrimental effects of insufficient pain relief and inadequate sedation in such unstable patients as children during pediatric cardiac ECMO, further studies on this topic seem urgently necessary.

Excessive bleeding on extracorporeal membrane oxygenation after surgical repair of type I truncus arteriosus: A case report.

Severe bleeding remains the most common complication of extracorporeal membrane oxygenation (ECMO) following surgical repair of congenital heart defects. We present a case of excessive hemorrhage within the first hours on ECMO support after repair of a type I truncus arteriosus. Bleeding control was achieved by surgical repair following failure of conventional interventions to control hemorrhage despite normalization of laboratory coagulation parameters. Aspects associated with bleeding and bleeding control during extracorporeal circulation after cardiac surgery are discussed.

A centrifugal pump driven tidal flow extracorporeal membrane oxygenation system tested with neonatal mock circulation.

In 1993, Chevalier published his experiences with tidal flow venovenous extracorporeal membrane oxygenation (ECMO) featuring a single lumen cannula, non-occlusive roller pump, and alternating clamps. Using a neonatal mock circulation (NMC), which enables different hemodynamic states for neonatal ECMO research, the tested hypothesis was that it is possible to create a centrifugal pump driven tidal flow neonatal venovenous ECMO system. Additionally, the resulting hemodynamic effects in a condition of circulatory impairment were investigated. The ECMO circuit tested was assembled using a pediatric centrifugal pump head, a distensible reservoir, and a rotary clamp separating drainage from the injection phase. Using the NMC, end tidal volumes, mock circulation flow, and arterial and venous pressures were measured at different pump speeds after the drainage and injection phases. Effective venovenous ECMO flow (evvEF) was calculated. Mock circulation baseline values (ECMO clamped) were compared to values during tidal flow ECMO. At 3,000 rpm, a centrifugal pump speed of 75 ml/kg/min evvEF was reached, and it increased with higher pump speeds. At this point, the end tidal mock circulation flow (representing cardiac output) after drainage differed significantly from that during the injection phase (p < 0.01) but not from the baseline value. The end tidal arterial and venous pressures after the drainage phase were found to be significantly decreased compared to the baselines (p < 0.01). In conclusion, a centrifugal pump driven tidal flow venovenous ECMO system can be created enabling sufficient tidal volumes. Tested in the described NMC simulating posthypoxic circulatory impairment, significant hemodynamic effects could be demonstrated. Animal experiments for confirmation are necessary.

[Hypoplastic left-heart syndrome. Initial intensive care experiences with the Norwood operation in Vienna]. / Hypoplastisches Linksherz-Syndrom. Erste intensivmedizinische Erfahrungen mit der Norwood-Operation in Wien.

Palliative surgery of the hypoplastic left heart syndrome (HLHS), whereby both pulmonary and systemic circulation are restored, was first described by Norwood in 1983. Careful ventilatory and pharmacologic modulation of the ratio of pulmonary to systemic vascular resistance are a crucial part of pre-, peri- and postoperative management. We report our experience in 3 of 7 newborns with HLHS who underwent the Norwood operation. Hemodynamic and respiratory parameters were evaluated retrospectively in these patients and we analysed the influence of diagnostic and therapeutic interventions on the course of disease before and after operation. During prostaglandin therapy two of three patients required mechanical ventilation preoperatively because of pulmonary hyperperfusion. Decreased myocardial contractility, oliguria and increased pulmonary vascular resistance characterized the postoperative course. The management included a careful application of inotropic support when necessary, adaptation of the ventilatory setting in order to modulate pulmonary perfusion and, in addition, institution of peritoneal dialysis. One patient died from staphylococcus aureus and superinfection with respiratory syncytial virus on day 41 after the operation. Maintaining an optimal balance between pulmonary and systemic blood flow is an essential aspect of postoperative management. Serum lactate and central venous oxygen saturation are helpful parameters in monitoring therapeutic measures in these patients. We conclude from our preliminary experience, that the Norwood operation might be an alternative therapeutic approach for newborns with HLHS in whom heart transplantation is not possible.

Decreasing reticulocyte counts associated with declining post-dose erythropoietin plasma levels in anaemia of prematurity.

UNLABELLED: A prospective sequential, multicentre trial was conducted to determine the association between erythropoietin (EPO) plasma levels and the erythropoietic response to recombinant human erythropoietin (r-HuEPO) during long-term treatment of premature infants. Twenty-nine infants, gestational ages 26-34 weeks and postnatal ages more than 14 days, received 600 IU r-HuEPO per kg per week divided into three doses subcutaneously for haemoglobin levels less than 120 g/l or haematocrit less than 36% over a period of 4 weeks. Eight additional patients were studied for a total of 10 weeks. EPO plasma concentrations and haematologic parameters were measured prior to the onset of treatment and at 2-weekly intervals thereafter. Treatment with r-HuEPO resulted in a median increase in corrected reticulocyte counts of 2.5% (range 0.2-4.6%) above patient's baseline, thereafter a decrease was observed. In the 8 patients followed for 10 weeks reticulocyte counts declined significantly during weeks 6-10 when compared with the first 4 weeks (p < 0.005). Median 72-hour post-dose EPO plasma levels increased significantly (p < 0.0001) to 57.3 mU/ml (range 5.0-160) above patient's baseline after the first injection, but declined progressively thereafter until they approached baseline values at week 10. CONCLUSION: R-HuEPO treatment after the first month was associated with a decrease in post-injection plasma levels and a decrease in erythropoietic response. This decrease in erythropoietin's efficacy and the decline observed in post-dose EPO plasma levels may be causally related.

A simple neonatal mock circulation enabling pulsatility and different hemodynamical states for neonatal ECMO research: application to assess the effect of a centrifugal pump operated neonatal ECMO system on the circulation.

In neonates, extracorporeal membrane oxygenation (ECMO) is increasingly used for circulatory support, e.g., after cardiac surgery. For training purposes and for research, animal experiments are usually required, complicated by increasing social issues, high costs, and limited reproducibility. Therefore, we designed a mechanical neonatal mock circulation (NMC) model enabling pulsatility and various hemodynamic conditions commonly occurring in neonates. Connected to a flow and pressure reading interface, a computer assisted data management system was installed. A nonocclusive roller pump combined with stiff and elastic tubing segments (for aortic pressure regulation and venous capacity) as well as constant and variable resistance (and optionally a patent duct) are essential features of the NMC system. To show the investigational potential, we studied the influence of venoarterial and venovenous ECMO on the NMC performance during normal circulation, hypovolemia, high arterial resistance, the combination of both, and in low cardiac output. By assessing the significant effects of ECMO on the circulatory function of the NMC, its feasibility and investigational properties could be demonstrated.

Follow-up of infants with congenital toxoplasmosis detected by polymerase chain reaction analysis of amniotic fluid.

This study was conducted to assess the validity of performing the polymerase chain reaction (PCR) on amniotic fluid for detecting fetal Toxoplasma infection. The primary endpoint was the outcome of the infant at 1 year of age. A prospective, consecutive study was performed in 49 infants born to mothers with primary Toxoplasma infection during pregnancy. PCR determinations of Toxoplasma gondii DNA in amniotic fluid were carried out as part of their prenatal management. Infants were examined at birth, and at 1, 3, 6, 9, and 12 months of age. Nine of 11 infants from pregnancies with positive PCR results proved to be infected based on follow-up serological investigations conducted during the first year of life. Two fetal deaths occurred. All 38 infants with negative PCR results remained uninfected at 1 year of age, irrespective of whether their mothers had received treatment with sulfadiazine/pyrimethamine or spiramycin alone. Psychomotor development was normal in all infants. This follow-up study confirms that PCR performed on amniotic fluid is a useful method for identification or exclusion of fetal Toxoplasma infection. Treatment of infected pregnant women and - in the event of a positive PCR result subsequent treatment of their infants is associated with a favorable outcome.

Single needle venovenous extracorporeal membrane oxygenation using a nonocclusive roller pump for rescue in infants and children.

In 1993, J.Y. Chevalier described a single needle venovenous extracorporeal membrane oxygenation (ECMO) system using a nonocclusive roller pump and alternating clamps for pulmonary support in neonates. We modified this system to use it in older children as well and for additional indications. Introducing a double raceway and 2 different sizes of tubing sets and performing percutaneous approach, we treated 21 children (age 1 day to 49 months) using this system. Indications for treatment were hypoxia and hypoxic induced myocardial dysfunction resulting from pulmonary failure, sepsis, and congenital defects. Of the children treated for neonatal indications, 7/9 survived. For 2 children ECMO was terminated because of intraventricular hemorrhage (IVH). In the pediatric group 5/7 of the children could be weaned from ECMO, and 2 children died after more than 30 days on ECMO. Two of the children who had been almost completely weaned died later because of therapy withdrawal following a brain death diagnosis. In the cardiac group, 3/5 of the children survived. We conclude that the described system is an effective venovenous ECMO system that reduces invasivity and expenditure.

Preoperative ECMO in congenital cyanotic heart disease using the AREC system.

BACKGROUND: In cyanotic congenital heart disease, oxygen delivery is impaired either by reduced pulmonary perfusion or by limited entry of oxygenated blood into the systemic circulation. Additional impairment of oxygen delivery (eg, in pulmonary hypertension) leads to hypoxic cerebral damage. Preoperative extracorporeal membrane oxygenation enables oxygenation in otherwise untreatable cases. METHODS: In 3 neonates suffering from cyanotic congenital heart disease (1 with tricuspid atresia and 2 with transposition of the great arteries) with arterial desaturation despite application of prostaglandins, balloon atrioseptostomy, and eventually inhaled nitric oxide during intermittent positive-pressure ventilation with an inspired oxygen fraction of 1, oxygenation could only be established by means of preoperative extracorporeal membrane oxygenation. We used a venovenous single-lumen cannula tidal-flow extracorporeal membrane oxygenation system described by Chevalier and associates that has previously been used for extracorporeal lung support. In this system, called AREC (assistence respiratoire extra-corporelle), alternating clamps and a nonocclusive roller pump were used. RESULTS: All 3 survived. CONCLUSIONS: We conclude that the AREC system enables sufficient preoperative oxygenation in patients with cyanotic congenital heart disease and hypoxia in spite of all conventional therapeutic means. This provides a stable preoperative condition for elective palliation or correction.

Extracorporeal membrane oxygenation in neonates.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO), originally developed as an artificial replacement for respiratory assistance, is decreasingly used in neonates with respiratory failure. Nevertheless, there is a constant need for this invasive and expensive neonatal treatment modality. INTERVENTION: Review of our experience (80 recent ECMO performances because of circulatory failure) and the literature. RESULTS: In contrary to reduced ECMO performances out of respiratory insufficiency in neonates, ECMO as circulatory support is increasingly used. Neonatal sepsis, pre- and postoperative cardiac failure, combined circulatory and respiratory failure after resuscitation and with congenital diaphragmatic hernia result in a permanent need for ECMO, whenever there are fewer ECMO treatments per year. Nonocclusive pumps, portable devices, small priming volumes and tapered anticoagulation protocols enable survival through ECMO even in virtually hopeless hemodynamic conditions. Special efforts in investigation and prevention of permanent neurological impairment, especially after severe pre-ECMO hypoxia seem to be mandatory. CONCLUSION: ECMO remains an important tool in neonatal and pediatric intensive care. However, the number of ECMO therapies was reduced due to respiratory therapeutic progress, but indications and ECMO technology have changed.