Search PubMed⌕ Search

Biomedical subjects

G Zobel

Publications and source records attributed to G Zobel.

At least 37 records · Page 2Linked to original sources

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↗

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↗

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↗

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↗

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↗

Procel burn cover used as a total body dressing in burns.

A 26-month-old boy sustained a scald injury covering 83 per cent of his total body surface area (TBSA). He also developed sepsis and multiorgan failure (MOF). Locally he was treated with Procel burn cover and silver sulphadiazine cream (SSD) for 23 days. By using Procel, the dressing-change time was shortened significantly. Procel burn cover controlled core and skin temperature more effectively compared to conventional dressing, and the staff acceptance increased because of its easy and fast use. Based on our observation, this material can be used successfully as a total body dressing with children with extensive partial thickness burns or temporarily in full thickness burns until wound excision can be performed.

Bandages↗

Inhaled nitric oxide versus inhaled prostacyclin and intravenous versus inhaled prostacyclin in acute respiratory failure with pulmonary hypertension in piglets.

This study was a prospective, randomized design to compare oxygenation and pulmonary hemodynamics between inhaled nitric oxide (NO) and inhaled prostacyclin (PGI2), and between inhaled and i.v. PGI2 in acute respiratory failure with pulmonary hypertension. Acute respiratory failure with pulmonary hypertension was induced in 12 piglets weighing 9-12 kg by repeated lung lavages and a continuous infusion of the stable endoperoxane analogue of thromboxane. Thereafter the animals were randomly assigned either for NO or PGI2 application. All animals were treated with different concentrations of NO or different doses of PGI2 applied i.v. and inhaled in random order. Continuous monitoring included ECG, central venous pressure (CVP), mean pulmonary artery pressure (MPAP), mean arterial pressure (MAP), arterial oxygen saturation (SaO2), and mixed venous oxygen saturation (SvO2) measurements. NO inhalation of 10 ppm resulted in a significant increase in PaO2/fraction of inspired oxygen (FiO2) from 7.8 +/- 1.34 kPa to 46.1 +/- 9.7 kPa. MPAP decreased significantly from 5.1 +/- 0.26 kPa to 3.7 +/- 0.26 kPa during inhaled NO of 40 ppm; i.v. infusion of PGI2 slightly increased oxygenation parameters. A significant increase in PaO2/FiO2 up to 32.4 +/- 3.1 kPa was observed during PGI2 aerosol delivery (p < 0.01); i.v. PGI2 decreased MAP from 11.5 +/- 0.39 kPa to 9.8 +/- 0.66 kPa (p < 0.05) and MPAP from 5.8 +/- 0.53 kPa to 4.5 +/- 0.66 kPa, respectively (p < 0.05). PGI2 aerosol delivery significantly decreased the MPAP to 3.7 +/- 0.53 kPa (p < 0.05) without influencing the MAP.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

[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↗

Proximal and tracheal airway pressures during different modes of mechanical ventilation: an animal model study.

OBJECTIVE: To determine the differences between the mean proximal and tracheal airway pressures during 3 different modes of mechanical ventilation (MV) in an animal model of acute cardiac failure (CF) and respiratory failure (RF). DESIGN: Prospective, randomized, cross-over design. SETTING: University research laboratory. SUBJECTS: Twelve young pigs weighing 10-16 kg. INTERVENTIONS: The experimental protocol consisted of 3 stable 30 min conditions: when ventricular and pulmonary function was normal (control), after the induction of acute cardiac failure by a beta-blocking agent and after respiratory failure induced by repeated lung lavages. Modes of MV included controlled mechanical ventilation (CMV), high-frequency oscillation (HFO), and high-frequency jet ventilation (HFJV). MEASUREMENTS AND RESULTS: The tracheal mean airway pressure (P(aw)) was measured at the distal port of the Hi-lo jet tube using an air-filled pressure transducer. The mean transpulmonary P(aw) increased significantly from 0.41 +/- 0.14 kPa during the control period to 1.15 +/- 0.17 kPa (P < 0.0001) during the RF period. In all study periods both the proximal and tracheal P(aw) were lowest during HFJV. There was no difference between the proximal and tracheal P(aw) during CMV and HFJV throughout the protocol. In the cardiac and respiratory failure periods the proximal P(aw) (CF, 1.45 +/- 0.08 kPa; RF, 3.13 +/- 0.27 kPa) was significantly higher than the tracheal P(aw) (CF, 1.04 +/- 0.09 kPa, P < 0.01; RF, 2.18 +/- 0.3 kPa, P < 0.01) with HFO. When ventilated by HFO, the mean external oscillatory amplitude was 4.33 +/- 0.14 kPa and the intratracheal oscillatory amplitude was only 0.49 +/- 0.06 kPa (P < 0.0001). CONCLUSION: HFJV provides adequate respiratory support at lower P(aw) than CMV and HFO. Proximal P(aw) closely reflects tracheal P(aw) during CMV and HFJV. However, with HFO great pressure differences between the proximal and tracheal airways are evident. Therefore, additional intratracheal airway pressure monitoring seems to be very useful for optimizing ventilator settings during HFO.

Acute Disease↗

Prolonged extracorporeal organ support in a 2-year-old boy after cardiac surgery.

A case report of a 2-year-old boy who developed severe post-operative low cardiac output, sudden cardiac arrest and consecutive multiple organ system failure after open heart surgery is described. Initially the hemodynamic situation was stabilized by extracorporeal membrane oxygenation (ECMO) combined with continuous hemofiltration (CHF) carried out for 7 days. Continuous veno-venous hemofiltration (CVVH) was necessary for further 17 days. One episode of plasmapheresis restored transiently a severe post-operative coagulopathy and enabled the removal of the pulmonary artery catheter and the chest tubes.

Cardiac Output, Low↗