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Biomedical subjects

B Urlesberger

Publications and source records attributed to B Urlesberger.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cytomegalovirus associated neonatal pneumonia and Wilson-Mikity syndrome: a causal relationship?

Lung injury caused by intrauterine inflammation has recently been strongly implicated in the pathogenesis of Wilson-Mikity syndrome (WMS). This article supports this theory by suggesting a causative role of intrauterine cytomegalovirus (CMV) infection for the development of WMS. A male premature infant, born at 33 weeks of gestational age, developed chronic lung disease compatible with WMS and diagnostic evaluation was positive for CMV infection. High-resolution computed tomography scan and lung histology revealed typical features of WMS in association with signs of interstitial pneumonia. CMV was found in urine, breastmilk, bronchoalveolar lavage material and lung tissue from open lung biopsy. Follow-up after treatment with ganciclovir and steroids showed resolving lung disease at the age of 6, 10 and 16 months, with lung function signs of mild obstruction. Assuming that a chance coexistence of cytomegalovirus pneumonia and Wilson-Mikity syndrome is rather unlikely, it is possible that intrauterine cytomegalovirus infection caused a pattern of lung injury consistent with Wilson-Mikity syndrome. Further cases of Wilson-Mikity syndrome should be investigated as to a possible role of congenital infection.

Cytomegalovirus Infections↗
PubMed1998

Serial lumbar tapping to prevent posthaemorrhagic hydrocephalus after intracranial haemorrhage in preterm infants.

Posthaemorrhagic ventricular dilation following intraventricular haemorrhage is a serious problem with high morbidity in preterm babies. No consensus exists as to the treatment of intraventricular haemorrhage and as to the treatment or prophylaxis of posthaemorrhagic ventricular dilation. Serial lumbar tapping was already in use to treat existing or being in the offing ventricular dilation. In the present study we evaluated the incidence of posthaemorrhagic hydrocephalus when lumbar tapping was initiated early, i. e. immediately before ventricular dilation had started. Between January 1989 and December 1996 37 preterm infants suffering from intraventricular haemorrhage grade III or grade III plus periventricular haemorrhage were enrolled in this study. Lumbar tapping was started as soon as possible: median (25. percentile-75. percentile) two (0-4) days after onset of haemorrhage. A median of 11 (8-17) punctures was performed in each patient. The outcome was as follows: 6 patients (16.2%) showed complete remission, 24 (64.9%) developed ventriculomegaly and 7 (18.9%) developed posthaemorrhagic hydrocephalus with subsequent need of shunt implantation. With the low incidence of shunt implantations in our study we suggest to reconsider the effectiveness of SLP performed immediately after onset of haemorrhage.

Cerebral Hemorrhage↗
PubMed1998

Quantification of cyclical fluctuations in cerebral blood volume in healthy infants.

Cyclical fluctuations in cerebral blood flow velocity in Doppler measurements are a well known phenomenon. In 1992 Livera et al have shown in one patient, that cyclical fluctuations of cerebral blood volume could be measured with near infrared spectroscopy (NIRS). The aim of the present study was a quantification of the amplitude of cyclical fluctuations of cerebral blood volume (represented by total haemoglobin [Hbtot]) in a large number of healthy infants. Furthermore changes of oxygenated haemoglobin (HbO2) and deoxygenated haemoglobin (Hb) were investigated. Measurements were done during two hours of undisturbed daytime sleep. Fifty-eight infants (30 male, 28 female) were included in the study. All but one infant showed cyclical fluctuations. For quantification of cyclical fluctuations only periods during quiet sleep with excellent tracing quality were used. A number of 7894 cycles was analyzed for each of the three NIRS parameters. The median amplitude of the cycling fluctuations was: delta Hbtot 1.1 mumol/l, delta HbO2 1.1 mumol/l, and delta Hb 0.2 mumol/l. The frequency was changing within a range of 3 to 6 cycles/minute. Polynominal regression analysis showed that the relationship of delta HbO2 and delta Hbtot was distinctively stronger compared to the relationship of delta Hb and delta Hbtot. In conclusion we think that these data represent "normal ranges" for parameter fluctuations in long-time NIRS tracings.

Blood Volume↗
PubMed1998

Effects of inhaled nitric oxide during permissive hypercapnia in acute respiratory failure in piglets.

OBJECTIVE: To look for the effects of inhaled nitric oxide on oxygenation and pulmonary hemodynamics during acute hypercapnia in acute respiratory failure. DESIGN: Prospective, randomized, experimental study. SETTING: University research laboratory. SUBJECTS: Ten piglets, weighing 9 to 13 kg. INTERVENTIONS: Acute respiratory failure was induced by oleic acid infusion and repeated lung lavages with 0.9% sodium chloride. The protocol consisted of three randomly assigned periods with different PaCO2 levels. Tidal volume was reduced to induce hypercapnia. Inspiratory time was prolonged to achieve similar mean airway pressures. During permissive hypercapnia, pH was not corrected. At each PaCO2 period, the animals were ventilated with inhaled nitric oxide of 10 parts per million and without nitric oxide inhalation. MEASUREMENTS AND MAIN RESULTS: Continuous hemodynamic monitoring included right atrial, mean pulmonary arterial, and mean systemic arterial pressures, arterial and mixed venous oxygen saturations, and continuous flow recording at the pulmonary artery. In addition, airway pressures, tidal volumes, dynamic lung compliance and airway resistance, end-tidal CO2 concentrations, and arterial and mixed venous blood gases were measured. Data were obtained at baseline and after lung injury, at normocapnia, at two levels of hypercapnia with and without nitric oxide inhalation. Acute hypercapnia resulted in a significant decrease in blood pH and a significant increase in mean pulmonary arterial pressure. There was no significant change in PaO2 during normocapnia and hypercapnia. Inhaled nitric oxide significantly decreased the mean pulmonary arterial pressure during both hypercapnic periods. It significantly improved oxygenation during both normocapnia and hypercapnia. CONCLUSIONS: Acute hypercapnia resulted in a significant increase in pulmonary arterial pressure without influencing oxygenation and cardiac output. Inhaled nitric oxide significantly reduced the pulmonary hypertension induced by acute permissive hypercapnia but did not influence the flow through the pulmonary artery. Inhaled nitric oxide significantly improved oxygenation in this model of acute lung injury during normocapnia and acute hypercapnia.

Administration, Inhalation↗
PubMed1998

Inhaled nitric oxide in infants and children after open heart surgery.

OBJECTIVE: To assess the effects of inhaled nitric oxide (NO) on oxygenation and pulmonary circulation in infants and children with critical pulmonary perfusion and/or hypoxemia after open heart surgery. STUDY: A prospective case series report. SETTING: A multidisciplinary pediatric intensive care unit in a University hospital PATIENTS: From June 1993 to March 1996 37 pediatric patients after open heart surgery were treated with inhaled NO. Their mean age was 2.9+/-0.6 years, their mean body weight 12.6+/-1.8 kg. METHODS: Inhaled NO was applied using a microprocessor controlled delivery system which continuously measured NO and NO2 by the chemilumniscence method. Monitoring included ECG, continuous pulse oximetry (SaO2), arterial (AP), central venous (CVP) and left atrial (LAP) pressures and in 8 patients a pulmonary artery (PAP) pressure. Inhaled NO was started at an SaO2 <90% with a fraction of inspired oxygen concentration (FiO2) >0.7, at a mean pulmonary artery pressure (MPAP) >50% of the mean arterial pressure (MAP), and in patients after Fontan-procedure at a CVP-LAP pressure gradient >10 mmHg. RESULTS: The mean dose of inhaled NO was 3.7+/-0.3 ppm and the mean duration was 112+/-14.7 hours. For the whole group SaO2 increased from 79.6+/-2.3 to 90.1+/-1.5% (p<0.01) within 20 minutes of NO-inhalation. Inhaled NO significantly decreased the MPAP from 47.8+/-4 to 27.5+/-2.3 mmHg (p<0.01) in 8 patients with postoperative pulmonary hypertension and significantly decreased the transpulmonary pressure (CVP-LAP) from 14.3+/-0.8 to 7.3+/-0.9 mmHg (p<0.01) in 16 patients after Glenn- or Fontan-procedure. CONCLUSIONS: Inhaled NO is very effective to decrease pulmonary artery pressure, to improve oxygenation, and to improve Fontan-circulation in infants and children after open heart surgery.

Administration, Inhalation↗
PubMed1998

Continuous renal replacement therapy in critically ill patients.

We describe our experience with continuous renal replacement therapy (CRRT) in critically ill neonates. From June 1995 to June 1997 36 critically ill oliguric or anuric infants and children underwent continuous arterio-venous (N = 17) or veno-venous (N = 15) renal support. In addition, four neonates were treated with continuous ultrafiltration (CUF) during extracorporeal membrane oxygenation (ECMO) because of severe diuretic-resistant hypervolemia. Their mean age was 9.8 +/- 1.5 days, their mean body weight 3.0 +/- 0.1 kg. The membrane surface area of the hemofilters ranged from 0.015 m2 to 0.2 m2 and the priming volume from 3.7 to 15 ml. For pump-driven hemofiltration a roller pump with pressure alarms, an air trap, an air bubble detector, and small blood lines was used. Fluid balance was controlled by a microprocessor controlled unit. The ultrafiltrate substitution fluid was based on bicarbonate in the majority of the patients and was partially or totally replaced according to the clinical situation. The mean duration of renal support was 97 +/- 20 hours, ranging from 14 to 720 hours. During arterio-venous and veno-venous hemofiltration the mean blood flow rates were 7.0 +/- 1.2 ml/min and 23.1 +/- 2.4 ml/min (P < 0.01), respectively, and the mean ultrafiltration rates 3.3 +/- 0.4 and 9.5 +/- 1.9 ml/min/m2 (P < 0.01), respectively. During continuous hemodiafiltration urea clearances increased by 300%. Overall survival rate was 66%. CRRT related complications included local bleeding at the catheter entrance site, partial thrombosis of the inferior or superior caval veins and transient ischemia due to femoral artery catheters. Continuous hemofiltration either driven in the arterio-venous or veno-venous mode is a very effective method of renal support for critically ill neonates to control fluid balance and metabolic derangement. Urea clearance can be improved by adding some dialysate fluid in a countercurrent direction to blood flow.

Acute Kidney Injury↗
PubMed1998

[Kinetic therapy of severe meconium aspiration syndrome].

Recent studies showed the possible positive effect of body position changes during mechanical ventilation of severe lung diseases in adult patients. In neonatology kinetic therapy is still rarely used, therefore we present this case report. A full term newborn suffering from severe MAS and peripartal asphyxia was transferred to our NICU to perform extracorporeal lung support, if necessary. After application of a natural porcine surfactant and start of inhalative nitric oxide therapy (10 ppm) a clinical stabilisation was possible. Because of hypercapnia, high frequency oscillation ventilation was introduced later on. The PaCO2 values decreased quickly. A few days later severe pulmonary secretion problems occurred, which led to atelectasis and barotrauma due to local hyperinflation. After several different ventilation strategies had failed to improve the situation, kinetic therapy in combination with conventional mechanical ventilation was started. Under this therapy-concept it was possible to reventilate the atelectatic lung areas, and quickly an improvement of oxygenation was seen. Weaning from the respirator was possible within one week. In conclusion, we think that an important progress in therapy was due to kinetic therapy.

Adult↗
PubMed1997

Assessment of lung function in neonates during extracorporeal membrane oxygenation.

We report our experience with pulmonary function testing in 11 out of 22 full-term neonates with severe respiratory failure, treated at the ECMO center Graz (Austria) during the period from 1990 to 1995. Altogether 17 out of 22 patients survived ECMO and all of them were successfully weaned from ECMO. Pulmonary function was assessed by monitoring expiratory tidal volume on the ventilator and estimating respiratory system compliance from the ratio tidal volume/(PIP-PEEP). In addition, compliance, and functional residual capacity were measured using a computerized pulmonary function system (PEDS). Compliance (mean +/- SD) decreased markedly after 24 hours of ECMO, compared with baseline values (0.20 +/- 0.12 vs 0.12 +/- 0.13 ml/cmH2O/kg) and was significantly higher (0.43 +/- 0.14 ml/cmH2O/kg, p < 0.01) before ECMO stop. When tidal volumes increased continuously ECMO blood flow could be decreased, indicating lung recovery. Most patients had a tidal volume of > 7 ml/kg prior to decannulation. Functional residual capacity and corresponding dynamic compliance, measured in 5 patients, ranged from 18.6 to 29.6 ml/kg and 0.49 to 0.57 ml/cmH2O/kg at this time. Functional residual capacity (mean +/- SD) increased significantly when surfactant was administered to promote weaning from ECMO (8.28 +/- 0.9 vs 19.0 +/- 1.0 ml/kg, p < 0.01). We conclude that the assessment of lung function has improved our understanding of pulmonary recovery during ECMO. Its clinical significance in determining the optimum time of weaning from ECMO needs further evaluation.

Extracorporeal Membrane Oxygenation↗
PubMed1997

Venous thrombosis in and after extracorporeal membrane oxygenation: detection and follow-up by color Doppler sonography.

The purpose of our study was to evaluate thrombosis of venous vessels during and after extracorporeal membrane oxygenation (ECMO) using color Doppler sonography. We prospectively performed serial color Doppler sonography investigations in 30 ECMO patients [age: newborn to 3 years, male:female = 20:10, venoarterial (VA) ECMO = 18, venovenous (VV) ECMO = 12]. During ECMO obstruction and/or thrombosis of the superior vena cava (SVC) was observed in 2 neonates on VA ECMO. Furthermore, a thrombotic clot from an initially open duct of Arantii with partial portal vein thrombosis, reaching into the inferior vena cava (IVC), occurred despite adequate heparinization. After ECMO, late septic SVC thrombus occurred in one neonate. IVC thrombus was observed in two pediatric VV ECMO patients. The overall incidence of venous clots was 20 % (6 of 30). Routine color Doppler sonography monitoring of vessels in children on and after ECMO was found to be useful for early detection of venous thrombosis. It enabled consequent administration of appropriate therapy as well as follow-up after decannulation and reconstruction.

Child, Preschool↗
PubMed1997

Inhaled nitric oxide in patients with critical pulmonary perfusion after Fontan-type procedures and bidirectional Glenn anastomosis.

OBJECTIVE: The aim of this study was to evaluate the effects of inhaled nitric oxide in patients with critical pulmonary perfusion after Fontan-type procedures and bidirectional Glenn anastomosis. METHODS: Inhaled nitric oxide (mean 4.1 +/- 0.7 ppm, 1.5 to 10 ppm) was administered in 13 patients (mean age 5.6 +/- 1.6 years, 1.5 to 17 years) with critical pulmonary perfusion (central venous pressure > 20 mm Hg or transpulmonary pressure gradient > 10 mm Hg) in the early postoperative period after total cavopulmonary connection (n = 9) or after bidirectional Glenn anastomosis (n = 4). RESULTS: In patients after total cavopulmonary connection inhaled nitric oxide therapy decreased central venous pressure by 15.3% +/- 1.4% (p = 0.0001) and transpulmonary pressure gradient by 42% +/- 8% (p = 0.0008) and increased mean systemic arterial and left atrial pressures by 12% +/- 3.6% (p = 0.011) and 28% +/- 8% (p = 0.007), respectively. Arterial and venous oxygen saturations improved by 8.2% +/- 1% (p = 0.005) and 14% +/- 4.3% (p = 0.03), respectively. In patients after bidirectional Glenn anastomosis inhaled nitric oxide therapy resulted in a decrease of central venous pressure by 22% +/- 1% and of the transpulmonary pressure gradient by 55% +/- 6% and improved arterial and venous oxygen saturations by 37% +/- 29% and 11% +/- 3%, respectively. Mean systemic arterial and left atrial pressures remained nearly unchanged. No toxic side effect was observed in any patient. CONCLUSION: Inhaled nitric oxide may play an important role in the management of transient critical pulmonary perfusion caused by reactive elevated pulmonary vascular resistance in the early postoperative period after Fontan-type operations and bidirectional Glenn anastomosis.

Administration, Inhalation↗
PubMed1997

Partial liquid ventilation combined with inhaled nitric oxide in acute respiratory failure with pulmonary hypertension in piglets.

This study was a prospective, randomized, controlled design to evaluate gas exchange, lung mechanics, and pulmonary hemodynamics during partial liquid ventilation (PLV) combined with inhaled nitric oxide (NO) in acute respiratory failure (ARF) with pulmonary hypertension (PH). ARF with PH was induced in 12 piglets weighing 9.7-13.7 kg by repeated lung lavages and the continuous infusion of the stable endoperoxane analog of thromboxane. Thereafter the animals were randomly assigned either for PLV or conventional mechanical ventilation (CMV) at a fractional concentration of inspired O2 (Fio2) of 1.0. Perfluorocarbon (PFC) liquid (30 mL kg-1) was instilled into the endotracheal tube over 5 min followed by 5 mL kg-1h-1. All animals were treated with different concentrations of NO (1-10-20 ppm) inhaled in random order. Continuous monitoring included ECG, right atrial (Pra), mean pulmonary artery (Ppa), pulmonary capillary (Ppc'), and mean arterial (Pa) pressures, arteria oxygen saturation, and mixed venous oxygen saturation measurements. During PLV Pao2/Fio2 increased significantly from 8.2 +/- 0.4 kPa to 34.8 +/- 5.1 kPa (p < 0.01), whereas Pao2/FiO2 remained constant at 9.5 +/- 0.4 kPa during CMV. The infusion of the endoperoxane analog resulted in a sudden decrease of Pao2/Fio2 from 34.8 +/- 5.1 kPa to 14.1 +/- 0.4 kPa (p < 0.01) in the PLV group and from 9.5 +/- 0.4 kPa to 6.9 +/- 0.2 kPa (p < 0.05) in the control group. Inhaled NO significantly improved oxygenation in both groups (Pao2/Fio2: 45.7 +/- 5.3 kPa during PLV and 25.9 +/- 4.7 kPa during CMV). During inhalation of NO mean Ppa decreased significantly from 7.8 +/- 0.26 kPa to 4.2 +/- 0.26 kPa (p < 0.01) in the PLV group and from 7.4 +/- 0.26 kPa to 5.1 +/- 0.13 kPa (p < 0.01) in the control group. As documented in the literature PLV significantly improves oxygenation and lung mechanics in severe ARF. In addition, when ARF is associated with severe PH, the combined treatment of PLV and inhaled NO improves pulmonary hemodynamics resulting in better oxygenation.

Administration, Inhalation↗
PubMed1997

Activation of the clotting system: heparin-coated versus non coated systems for extracorporeal circulation.

UNLABELLED: The purpose of this experimental study was to compare heparin-coated versus non-coated systems for extracorporeal membrane oxygenation (ECMO), to investigate the dynamic course of clotting activation in both groups. METHODS: Eight pigs weighing 19.7 (+/- 1.3) kg, each underwent ECMO for 24 hours. Two groups were formed: in group 1, heparin-coated circuits were used with low dose heparinization (10 IU/kg/hr), whereas in group 2 non-coated circuits with high dose heparinization (60 IU/kg/hr) were used. Coagulation was monitored by measuring prothrombin time, partial thromboplastin time, fibrinogen, antithrombin III (AT III) and specific markers of clotting activation (thrombin-antithrombin III complexes (TAT) and D-dimer). Furthermore, platelet count, hematocrit, activated clotting time (ACT), and plasma heparin concentration were determined regularly RESULTS: The dynamic course of the specific coagulation activation markers showed some differences: whereas TAT and D-dimer increased quickly in group 2, the increase in group 1 was delayed. Activation marker values tended to be lower in group 1 during the first six hours, after which no more differences between the groups were seen. After 24 hours of ECMO, TAT and D-dimer had nearly returned to baseline values. Platelets showed a continuous decrease throughout the experiment, which was very similar in both groups. CONCLUSIONS: The heparin coated system showed a distinct delay in clotting activation during the first six hours of ECMO. After six hours there were no more differences between the groups.

Animals↗
PubMed1996

Congenital central hypoventilation syndrome (Ondine's curse syndrome) in two siblings: delayed diagnosis and successful noninvasive treatment.

UNLABELLED: Congenital central hypoventilation syndrome (CCHS, Ondine's curse syndrome) is a rare respiratory disorder; less than 100 cases have been reported. Familiality of the disease has been discussed, but only few familial cases have been reported so far. In this report we describe the occurrence of CCHS in two male siblings. Diagnosis was established only at the age of 4 years in the first case, although the patient had disease related symptoms since early infancy. The second patient was one of dizygotic twins, he was diagnosed with CCHS at the age of 8 months. Up to that age only moderate desaturations had been observed. The other twin was unaffected by the disease. Both patients were successfully treated by nocturnal positive-pressure ventilation via a specially adapted face mask. They show satisfactory physical and neurologic development. CONCLUSION: Our cases support the assumption of familiality in CCHS although the mode of inheritance remains to be clarified. Polygraphic recordings including capnography should be performed in siblings of CCHS patients early in life in order to avoid secondary complications. Noninvasive treatment by ventilation via special face masks is feasible.

Child↗
PubMed1996

Activation of the clotting system during extracorporeal membrane oxygenation in term newborn infants.

OBJECTIVES: To determine the degree of clotting activation that occurs with the usual anticoagulation regimen with systemic heparinization. METHODS: To allow a standardized comparison of the patients, this study focused on the first 48 hours of extracorporeal membrane oxygenation (ECMO) in term newborn infants. The ECMO perfusion circuit consisted of a roller pump, silicone membrane lungs, and silicone rubber tubing. Coagulation was controlled routinely by measuring prothrombin time, fibrinogen, antithrombin III, and reptilase time. Platelet counts, activated clotting time, and heparin concentration were controlled regularly. The following specific activation markers of the clotting system were measured: prothrombin activation fragment 1 + 2(F1+2), thrombin-antithrombin III complexes, and D-dimer. Measurements were done before the start of ECMO, after 5 minutes, and at hours 1, 2, 3, 4, 6, 12, 24 and 48. RESULTS: All seven term infants had excessively high levels of clotting activation markers within the first 2 hours of ECMO: F1+2, 11.6(+/- O.9) nmol/L (mean +/- SEM); thrombin-antithrombin, 920(+/- 2.2) microg/L; D-dimer, 15.522(+/- 3.689) ng/L. During the next 46 hours of ECMO, F1+2 and thrombin-antithrombin III complexes decreased from those high values, whereas D-dimer did not. The increase of activation markers was accompanied by low fibrinogen, low platelet counts. and prolongation of reptilase time. CONCLUSIONS: These findings fit the pattern of consumptive coagulopathy during neonatal ECMO, especially in the first 24 hours.

Anticoagulants↗
PubMed1995

Sonographically guided cannula positioning for extracorporeal membrane oxygenation.

Drainage problems due to catheter malpositioning are acutely life-threatening in patients undergoing extracorporeal membrane oxygenation. In order to reduce these complications we introduced sonographically guided catheter positioning. We compare the outcome in a group of patients with blind cannula positioning to that in a group with sonographically guided catheter positioning. Our results show that neonates and young infants especially are at high risk of drainage problems due to catheter malposition and that their outcome could be markedly improved by introducing sonographically guided cannula insertion.

Catheterization↗
PubMed1995

[Extracorporeal membrane oxygenation in newborn infants and children].

The purpose of this report is to describe our experience with veno-arterial (VA) and veno-venous extracorporeal membrane oxygenation (VV-ECMO) for neonates and children with severe acute respiratory or cardiocirculatory failure. From 1990 to 1994 20 neonates and 12 children were treated at the ECMO center in Graz. Indications for ECMO were acute respiratory failure in 27 patients and cardiocirculatory failure in 5 patients. Mean duration of ECMO was 228 +/- 30 hours. Fifteen neonates were weaned from ECMO and were subsequently extubated. Of the 12 children 7 had severe acute respiratory failure and underwent VV-ECMO. Five of these 7 children were weaned from ECMO and subsequently extubated. Only two of 5 patients with cardiac ECMO support could be weaned from bypass; one patient subsequently died, but the other patient is a long-term survivor. All patients with cardiac ECMO support after open heart surgery had severe mediastinal bleeding. The survival rate in neonates and pediatric patients with respiratory failure treated by ECMO was 75% and 71%, respectively, whereas it was only 20% in children with cardiocirculatory failure. Major complications on ECMO were local and intracerebral bleeding. ECMO is an effective therapy for neonates and children with acute respiratory failure. It is less effective for cardiac support in children after open heart surgery, but the use of heparin-layered ECMO systems might increase the safety of the procedure.

Carbon Dioxide↗