Anja K Metzger

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BACKGROUND Hyperventilation during cardiopulmonary resuscitation (CPR) is harmful. METHODS We tested the hypotheses that, during CPR, 2 breaths/min would result in higher cerebral perfusion pressure and brain-tissue oxygen tension than 10 breaths/min, and an impedance threshold device (known to increase circulation) would further enhance cerebral(More)
BACKGROUND Time to awakening after out-of-hospital cardiac arrest (OHCA) and post-resuscitation therapeutic hypothermia (TH) varies widely. We examined the time interval from when comatose OHCA patients were rewarmed to 37°C to when they showed definitive signs of neurological recovery and tried to identify potential predictors of awakening. METHODS With(More)
BACKGROUND The intrathoracic pressure regulator (ITPR) was created to improve hemodynamics by generating continuous negative airway pressure between positive pressure ventilations to enhance cardiac preload in apnoeic animals. In normovolemic and hypovolemic pigs, we tested the hypothesis that continuous negative intrathoracic pressure set at -5 or -10mmHg,(More)
We review the physiology and affects of inspiration through a low level of added resistance for the treatment of hypotension. Recent animal and clinical studies demonstrated that one of the body's natural response mechanisms to hypotension is to harness the respiratory pump to increase circulation. That finding is consistent with observations, in the 1960s,(More)
OBJECTIVE Generation of negative intrathoracic pressure during the decompression phase of cardiopulmonary resuscitation enhances the refilling of the heart. We tested the hypothesis that when compared with closed-chest manual compressions at 80 chest compressions per min, treatment with active compression-decompression cardiopulmonary resuscitation at 80(More)
OBJECTIVE To test the hypothesis that an impedance threshold device would increase systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure and delay the onset of symptoms and cardiovascular collapse associated with severe central hypovolemia. DESIGN Prospective, randomized, blinded trial design. SETTING Human physiology(More)
BACKGROUND A novel device, the intrathoracic pressure regulator (ITPR), combines an inspiratory impedance threshold device (ITD) with a vacuum source for the generation of controlled -10 mm Hg vacuum in the trachea during cardiopulmonary resuscitation (CPR) while allowing positive pressure ventilation. Compared with standard (STD) CPR, ITPR-CPR will enhance(More)
OBJECTIVE To evaluate the potential to use subatmospheric intrathoracic pressure to regulate intracranial pressure (ICP) in normovolemic and hypovolemic animals, we tested the hypothesis that mechanical devices designed to reduce intrathoracic pressure will decrease ICP in a dose-related manner. An inspiratory impedance threshold device was used in(More)
BACKGROUND The intrathoracic pressure regulator (ITPR) plus positive pressure ventilation (PPV) has been shown to improve coronary and cerebral perfusion pressures during hypovolemia by improving mean arterial blood pressure and by decreasing right atrial and intracranial pressures. We hypothesized that application of intermittent negative intrathoracic(More)
BACKGROUND The respiratory pump can be optimized to enhance circulation in patients with hypotension by having patients spontaneously breathe through a low level of inspiratory resistance. This can be achieved with an impedance threshold device (ITD) designed to provide 7 cm H2O resistance during spontaneous inspiration with minimal resistance during(More)