A method and device are provided for simultaneously or near-simultaneously diagnosing and treating tension pneumothorax and/or hemothorax. A Veress-type needle portion includes a hollow needle for puncturing the chest wall over a blunt hollow probe biased by one or more springs to extend distally into the pleural cavity. Openings in the blunt hollow probe connect via a pathway to an automatic check valve, which permits the flow of air and/or fluid only in a proximal direction. Pressure from within the pleural cavity is transmitted to the interior surface of a pressure documenter. If pressure greater than atmospheric pressure is present in the pleural cavity, the pressure documenter will be automatically urged proximally to simultaneously allow air and/or fluid to escape from the pleural space through the device, thus treating the tension pneumothorax and/or hemothorax, as well as providing a stable indicator to positively document the diagnosis of increased pressure.

Guidewires include a distal section, a proximal section and a middle section disposed between the distal section and the proximal section, wherein the middle section has a flexural stiffness that is greater than a flexural stiffness of both of the distal section and the proximal section. The distal section is configured for insertion into a vasculature of a patient. A diameter of the middle section may be greater than a diameter of the distal section. The guidewires may include a tapered distal transition portion disposed between the distal section and the middle section and a solid core wire extending a length of the guidewires, the solid core wire including a first diameter extending along the distal section, a second diameter extending along the proximal section, and a third diameter extending along the middle section, wherein the third diameter is greater than the first diameter and second diameter.