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M Reyle-Hahn

Publications and source records attributed to M Reyle-Hahn.

16 recordsLinked to original sources
PubMed2005

Effects of xenon anaesthesia on the circulatory response to hypoventilation.

BACKGROUND: Circulatory response to hypoventilation is aimed at eliminating carbon dioxide and maintaining oxygen delivery (DO(2)) by increasing cardiac output (CO). The hypothesis that this increase is more pronounced with xenon than with isoflurane anaesthesia was tested in pigs. METHODS: Twenty pigs received anaesthesia with xenon 0.55 MAC/remifentanil 0.5 microg kg(-1) min(-1) (group X, n=10) or isoflurane 0.55 MAC/remifentanil 0.5 microg kg(-1)min(-1) (group I, n=10). CO, heart rate (HR), mean arterial pressure (MAP) and left ventricular fractional area change (FAC) were measured at baseline, after 5 and 15 min of hypoventilation and after 5, 15 and 30 min of restored ventilation. RESULTS: CO increased by 10-20% with both anaesthetics, with an equivalent rise in HR, maintaining DO(2) in spite of a 20% reduction in arterial oxygen content. Decreased left ventricular (LV) afterload during hypoventilation increased FAC, and this was more marked with xenon (0.60-0.66, P<0.05 compared with baseline and isoflurane). This difference is attributed to negative inotropic effects of isoflurane. Increased pulmonary vascular resistance during hypoventilation was found with both anaesthetics. CONCLUSION: The cardiovascular effects observed in this model of moderate hypoventilation were sufficient to maintain DO(2). Although the haemodynamic response appeared more pronounced with xenon, differences were not clinically relevant. An increase in FAC with xenon is attributed to its lack of negative inotropic effects.

Analysis of Variance↗
PubMed2005

Xenon anaesthesia may preserve cardiovascular function in patients with heart failure.

BACKGROUND: The hypothesis that xenon anaesthesia provided haemodynamic stability was tested in patients with heart failure in a prospective, randomized, single-blind design. METHODS: Twenty-six patients scheduled for implantation of a cardioverter-defibrillator (ICD) received xenon 60-65% in oxygen (xenon group, n = 12) or propofol 3 mg/kg/h (propofol group, n = 14), both combined with remifentanil 0.2 microg/kg/min. After induction of anaesthesia with etomidate and remifentanil, heart rate (HR), mean arterial pressure (MAP) and left ventricular ejection fraction (LVEF) were recorded. After 60 min of propofol or xenon anaesthesia, the same parameters were recorded. RESULTS: While HR decreased in both groups, MAP was unchanged with xenon (73 vs. 76 mmHg) and decreased with propofol (from 78 to 64 mmHg, P < 0.02). LVEF was stable in both groups [32% vs. 37%, xenon (NS), and 30% vs. 34%, propofol (NS)]. Preload, as measured by end-diastolic volume (EDV), did not change (66 vs. 63 ml with xenon; 79 vs. 81 ml with propofol, both NS). Afterload, as determined by end-systolic pressure-volume product (ESPV), decreased with propofol (6760 vs. 4920 ml mmHg) but not with xenon (4060 vs. 3780 ml mmHg, P < 0.01 between groups). CONCLUSION: With propofol, MAP is reduced and LVEF is not increased in spite of reduced afterload. In contrast, MAP and LVEF are maintained with xenon.

Aged↗
PubMed2002

Increased airway resistance during xenon anaesthesia in pigs is attributed to physical properties of the gas.

BACKGROUND: In this study we investigated the effects of the physical properties of xenon on respiratory mechanisms in pigs. METHODS: With institutional approval, 10 female pigs (mean 25.2 (SD 2.5) kg) were anaesthetized with thiopental, remifentanil, and pancuronium. Gas flow and pressure were recorded continuously at the proximal end of the tracheal tube during constant flow ventilation for control, with 100% oxygen (control), followed by 1.5% isoflurane in 70/30% nitrogen/oxygen, 1.0% isoflurane in 70/30% nitrous oxide/oxygen, and 70/30% xenon/oxygen in random order. Compliance (C) and resistance (R) were calculated using a single compartment model. Resistance was corrected for gas viscosities eta and also for densities pho and viscosities eta as (pho*eta)(1/2) to compare assumptions of laminar and mixed flow in the airways. RESULTS: With constant flow ventilation, xenon increases inspiratory pressure compared with other gas mixtures. There were no significant differences in resistance, corrected for laminar or mixed flow, between the gas mixtures. Xenon anaesthesia did not affect compliance. CONCLUSIONS: The increase in airway pressure observed with xenon anaesthesia is attributed completely to its higher density and viscosity. Therefore, determination of airway resistance must take into account the physical properties of the gas. Xenon does not exert any major effect on airway diameter.

Airway Resistance↗
PubMed2000

[Xenon--a new anesthetic].

Today, xenon anaesthesia becomes an interesting object due to xenon's positive ecological aspects as well as its nearly ideal properties as an anaesthetic gas. The application of xenon provides advantages regarding intraoperative hemodynamic stability and the recovery period. Xenon increases tissue perfusion in most organ systems. This increase of tissue perfusion during an operation can be important during some surgical procedures and may improve postoperative outcome. In anaesthetic concentrations xenon leads to an increase in cerebral perfusion. For that reason, xenon should be avoided in patients with increased cerebral pressure or cerebral perfusion disorders. Therefore, further clinical investigations are necessary to improve these clinical findings. The development of accepted indications of xenon anaesthesia becomes necessary regarding a limited availability and high costs of the gas. Focussing this target, more clinical and experimental investigations will become necessary in the next years.

Anesthetics, Inhalation↗
PubMed2000

[Transfusion law].

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Blood Transfusion↗
PubMed2000

Effect of PEEP and inhaled nitric oxide on pulmonary gas exchange during gaseous and partial liquid ventilation with small volumes of perfluorocarbon.

BACKGROUND: Partial liquid ventilation, positive end-expiratory pressure (PEEP) and inhaled nitric oxide (NO) can improve ventilation/perfusion mismatch in acute lung injury (ALI). The aim of the present study was to compare gas exchange and hemodynamics in experimental ALI during gaseous and partial liquid ventilation at two different levels of PEEP, with and without the inhalation of nitric oxide. METHODS: Seven pigs (24+/-2 kg BW) were surfactant-depleted by repeated lung lavage with saline. Gas exchange and hemodynamic parameters were assessed in all animals during gaseous and subsequent partial liquid ventilation at two levels of PEEP (5 and 15 cmH2O) and intermittent inhalation of 10 ppm NO. RESULTS: Arterial oxygenation increased significantly with a simultaneous decrease in cardiac output when PEEP 15 cmH2O was applied during gaseous and partial liquid ventilation. All other hemodynamic parameters revealed no relevant changes. Inhalation of NO and instillation of perfluorocarbon had no additive effects on pulmonary gas exchange when compared to PEEP 15 cmH2O alone. CONCLUSION: In experimental lung injury, improvements in gas exchange are most distinct during mechanical ventilation with PEEP 15 cmH2O without significantly impairing hemodynamics. Partial liquid ventilation and inhaled NO did not cause an additive increase of PaO2.

Administration, Inhalation↗
PubMed2000

Remifentanil and propofol for sedation in children and young adolescents undergoing diagnostic flexible bronchoscopy.

Flexible fibreoptic bronchoscopy (FOB) has become a useful diagnostic and therapeutic procedure in children. We investigated 26 patients (3-14 years) for FOB using a new sedation strategy. All patients received oral premedication and inhalation of topical anaesthetic. Sedation for bronchoscopy was achieved with a continuous infusion of remifentanil and intermittent boluses of propofol. Propofol injection was repeated if sedation was inadequate. Sedation could be successfully performed in all children without adverse effects. Endtidal CO2 concentration and arterial oxygen saturation remained stable throughout the study. All children were awake 5+/-1.3 min after stopping remifentanil infusion. Sedation with remifentanil/propofol is a new sedation strategy for diagnostic flexible paediatric bronchoscopy in children with spontaneous ventilation.

Adolescent↗
PubMed1999

Fluctuations of inspired concentrations of nitric oxide and nitrogen dioxide during mechanical ventilation.

BACKGROUND: Nitric oxide (NO) is a very reactive agent with potentially toxic oxidation products such as nitrogen dioxide (NO2). Therefore, during NO inhalation a constant inspired concentration and accurate measurement of NO and NO2 concentrations are essential. The objective of this study was to test the NO concentrations at various positions along the inspiratory limb of the breathing circuit using a recently developed system to administer NO in phase with inspiratory flow during mechanical ventilation (Servo 300 NO-A, Siemens, Sweden). Furthermore, we tested whether an active heating system would interfere with inspired NO concentrations. RESULTS: A sharp decline in the NO concentration was found between the respirator's inspiratory outlet and more distal points along the inspiratory limb of the circuit. This finding was most evident when an active heating system was mounted between those points. CONCLUSIONS: The concentrations of NO and NO2 should be measured as near to the patient as possible, as significant fluctuations of these concentrations might be found along the inspiratory limb of the respiratory circuit especially when an active heating system is used.

Journal Article↗
PubMed1997

Coagulation techniques are not important in directing blood product transfusion during liver transplantation.

Preoperative acquired clotting parameters such as prothrombin time, activated partial thromboplastin time, antithrombin III, platelet concentration, and fibrinogen show coagulopathy caused by insufficiency of the diseased liver. Intraoperative determination of clotting factors or parameters is not helpful to direct intraoperative transfusion of blood, blood components, or platelets because transfusions performed solely for correction of clotting data do not correlate with the real intraoperative requirements and increase the costs of orthotopic liver transplantation. However, the use of antihyperfibrinolytic drugs seems to reduce intraoperative blood loss. Patients with cirrhotic disorders caused by portalvenous hypertension show extensive collaterals and increased intravascular blood volume. Thus it is plausible that especially overcorrection of blood loss during the surgical preparation in the preanhepatic phase of the operation results in extensive blood loss. Therefore, to avoid blood loss we attempt to keep volume substitution to a minimum during the preanhepatic phase of the operation. In contrast, during the anhepatic and postanhepatic phases we attempt to reestablish normovolemia by transfusing red packed blood cells and fresh-frozen plasma. Strictly confined use of blood products in the preanhepatic phase, followed by later correction of intravascular blood volume, may reduce intraoperative blood loss; it also seems to ensure adequate substitution of clotting factors.

Blood Coagulation↗