Ischemia-reperfusion-induced unmeasured anion generation and glycocalyx shedding: sevoflurane versus propofol anesthesia.

Introduction: Vascular leakage after ischemia-reperfusion (IR) is largely attributed to the destruction of the endothelial barrier and its associated negatively charged glycocalyx. In vitro, sevoflurane attenuates these changes. Therefore, we compared sevoflurane with propofol with regard to the protection of the glycocalyx and the release of negatively charged substances in vivo.

Functional hemodynamic parameters do not reflect volume responsiveness in the immediate phase after acute myocardial ischemia and reperfusion.

Objective: Functional preload parameters such as stroke-volume variation (SVV) and pulse-pressure variation (PPV) are superior to filling pressures when assessing volume responsiveness in mechanically ventilated patients. This investigation studied their application in the setting of acute myocardial ischemia and reperfusion (I/R).

Design And Setting: Experimental animal study in a university laboratory.

Effect of inhaled and intravenous lidocaine on inflammatory reaction in endotoxaemic rats.

Background And Objective: Systemically administered lidocaine has been shown to have anti-inflammatory properties. Inhalation is an attractive way of application because of high pulmonary compound concentrations and potentially fewer systemic side effects. The aim of this study was to clarify whether inhaled or, likewise, intravenous lidocaine can attenuate the inflammatory response in a model of experimental endotoxaemia in the rat.

The initial tangent of the aortic pressure increase is an estimate of left ventricular contractility in pigs.

The aim was, to identify an estimate of left ventricular contractility derived from the aortic pressure wave without load changing manoeuvres. For this purpose, left ventricular contractility was assessed with several aortic pressure wave form derived parameters and was compared to standard parameters of left ventricular contractility (conductance technique) in an experimental study. Measurements were taken during baseline, after beta-stimulation and after injection of a beta-antagonist.

Causes of metabolic acidosis in canine hemorrhagic shock: role of unmeasured ions.

Introduction: Metabolic acidosis during hemorrhagic shock is common and conventionally considered to be due to hyperlactatemia. There is increasing awareness, however, that other nonlactate, unmeasured anions contribute to this type of acidosis.

Methods: Eleven anesthetized dogs were hemorrhaged to a mean arterial pressure of 45 mm Hg and were kept at this level until a metabolic oxygen debt of 120 mLO2/kg body weight had evolved.

Positive end-expiratory pressure does not compromise myocardial contractility in myocardial ischemia/reperfusion.

Therapy for severe myocardial ischemia/reperfusion sometimes necessitates intermittent positive pressure ventilation, which may impair left ventricular function by reduction of ventricular loading. It is unknown today whether positive airway pressure also affects contractile force after myocardial ischemia/reperfusion. The authors tested whether positive end-expiratory pressure (PEEP) impairs myocardial contractility in acute ischemic heart failure.

The influence of positive end-expiratory pressure on stroke volume variation and central blood volume during open and closed chest conditions.

Objective: Intermittent positive pressure ventilation and positive end-expiratory pressure (PEEP) affect cardiac preload. Their effect is dependent on chest wall compliance. This study compares the effects of intermittent positive pressure ventilation and PEEP on stroke volume variation and central blood volume during open and closed chest conditions.

The influence of cardiac preload and positive end-expiratory pressure on the pre-ejection period.

The pre-ejection period (PEP) has recently been described as a potential parameter for monitoring cardiac preload. This study further investigated the influence of changes in intravascular volume status and the application of positive end-expiratory pressure (PEEP) on the pre-ejection period. In ten pigs, ECG, arterial pressure and stroke volume derived from an aortic flowprobe were registered.

Oxygent as a top load to colloid and hyperoxia is more effective in resuscitation from hemorrhagic shock than colloid and hyperoxia alone.

Perfluorocarbon (PFC) emulsions are intravascular oxygen therapeutics that temporarily enhance tissue oxygenation in dilutional anemia. However, PFC emulsions are not resuscitation fluids because PFCs only work optimally in the presence of high O2 partial pressure (hyperoxia); moreover, because they have no oncotic potential, dosing limitations prevent their use to permanently replace large hemorrhage volumes. Our objective was to clarify whether in the presence of hyperoxia a conventional colloid therapy supplemented by PFC is more efficacious than colloid alone.

Effects of perfluorohexan vapor on gas exchange, respiratory mechanics, and lung histology in pigs with lung injury after endotoxin infusion.

Background: Inhaled perfluorohexan vapor has been shown to improve gas exchange and pulmonary mechanics in oleic acid- and ventilator-induced lung injury. However, in the clinical setting, lung injury frequently occurs in the context of systemic inflammation and consecutive lung injury, which may be induced experimentally by intravenous administration of endotoxin. The authors studied whether vaporized perfluorohexan is efficacious during endotoxin-induced lung injury in domestic pigs.

Effect of prostaglandin I2 analogues on left ventricular diastolic function in vivo.

The prostaglandin I2 analogues epoprostenol and iloprost increase left ventricular contractility. Therefore, we hypothesize that the prostaglandin I2 analogues epoprostenol and iloprost improve also left ventricular diastolic function. To test this hypothesis, the effects of epoprostenol and iloprost on left ventricular diastolic function were assessed in vivo and compared to two vasodilators sodium nitroprusside and adenosine, not formerly associated with changes of left ventricular contractility.

Regional blood flow during hyperoxic haemodilution.

Background: Ventilation with pure oxygen (hyperoxic ventilation, HV) increases arterial oxygen content (CaO(2)). However HV induces arteriolar constriction and thus potentially affects O(2) supply. We therefore investigated the effects of HV on regional blood flow (RBF) and O(2) supply of different vital organs during moderate normovolaemic anaemia.

Aerosol delivery during mechanical ventilation to the rat.

The authors have adjusted a jet nebulizer to a mechanical ventilator (Servo Ventilator, Siemens) to deliver an aerosol to rats. They aimed to clarify whether a modified jet nebulizer generating particles with a mass median aerodynamic diameter of 2 microm would be effective and safe in intubated ventilated rats. Fluorescent microspheres (diameter: 1.

Mycoplasma haemocanis infection--a kennel disease?

Mycoplasma haemocanis (formerly Haemobartonella canis) is a red blood cell parasite that causes disease mainly in immunosuppressed and splenectomized dogs. Clinical outbreak of the disease resulted in failure of a large experimental project. We aimed to identify whether M.

Polyclonal anti-thymocyte globulins influence apoptosis in reperfused tissues after ischaemia in a non-human primate model.

Reperfusion triggers the expression of inflammatory cytokines and adhesion molecules that increase the rate of apoptosis in the reperfused tissues after ischaemia, thus worsening the outcome of the grafts. Polyclonal anti-thymocyte globulins (pATGs) are able to reduce the number of lymphocytes as well as block adhesion molecules and induce apoptosis in T-lymphocytes through Fas-ligand. The aims of this study were to investigate the influence of pATGs on the prevention of apoptosis of reperfused tissues after ischaemia and to monitor their capability to enhance lymphocyte apoptosis thus decreasing the deleterious effects of ischaemia/reperfusion injury (IRI).

Hyperoxic ventilation reduces six-hour mortality after partial fluid resuscitation from hemorrhagic shock.

Ventilation with 100% oxygen (Fio(2) 1.0; hyperoxic ventilation; HV) as an alternative to red blood cell transfusion enables survival in otherwise lethal normovolemic anemia. The aim of the present study was to investigate whether HV as a supplement to fluid infusion therapy could also restore adequate tissue oxygenation and prevent death in otherwise lethal hemorrhagic shock.

Hyperoxic ventilation reduces 6-hour mortality at the critical hemoglobin concentration.

Background: Acute normovolemic hemodilution reduces the circulating erythrocyte mass and, thus, the hemoglobin concentration. After extreme acute normovolemic hemodilution to the critical hemoglobin concentration (Hbcrit), oxygen demand of the tissues is no longer met by oxygen supply, and death occurs with increasing oxygen debt. The aim of the current study was to investigate whether ventilation with 100% oxygen (fraction of inspired oxygen [FiO2] = 1.

The prostaglandins epoprostenol and iloprost increase left ventricular contractility in vivo.

Objective: The principal effects of prostaglandin I(2) are vasodilation and inhibition of platelet aggregation induced by a rise in the intracellular second messenger cAMP. In the heart a rise in intracellular myocardial cAMP increases contractility. We examined whether prostaglandin I(2) increases left ventricular contractility in vivo.