CPR device having valve for increasing the duration and magnitude of negative intrathoracic pressures

摘要

According to the invention, methods and devices for increasing cardiopulmonary circulation induced by chest compression and decompression when performing cardiopulmonary resuscitation are provided. Cardiopulmonary circulation is increased according to the invention by impeding airflow into a patient's lungs to enhance the extent and duration of negative intrathoracic pressure during decompression of the patient's chest. Enhanced extent and duration of negative of intrathoracic pressure thus promotes venous blood flow into the heart and lungs from the peripheral venous vasculature. In one embodiment, impeding the airflow into the patient's lungs is accomplished by placing a ventilation tube in the patient's airway. The ventilation tube contains either a flow restrictive orifice disposed within or connected in series with a lumen of the ventilation tube, or a pressure-responsive valve within a lumen of the tube to impede the inflow of air. In a preferred embodiment, the patient's mouth and nose are covered with a facial mask which can impede airflow into the patient's airway. Also provided is an improved endotracheal tube to allow air to be impeded from flowing to the patient's lungs during decompression. Another apparatus according to the invention provides for an improved air-delivery system comprising a compressible structure which has been modified to allow for the impedance of the flow of gases to the patient's lungs. Also, the compressible structure is interfaced with the patient, preferably by attaching a facial mask or an endotracheal to the structure.