Portable needle assembly with adjustable length needle

A needle assembly for treating tension pneumothorax includes an elongated needle disposed within an elongated catheter, and a housing for containing the needle and catheter. The needle is coupled to the housing through a length adjustment mechanism so that the needle and the catheter are configured to be deployed out of the distal end of the housing to a pre-determined length. The length adjustment mechanism may include an axial path in the wall of the housing, grooves extending off of the axial path, and a protruding arm coupled to the needle. The protruding arm of the needle is configured to extend through the axial path of the housing and be grasped by a user to deploy the needle and catheter out of the distal end of the housing. When the needle is deployed to a desired length, the user may lock the needle and catheter in place by positioning the protruding arm in the corresponding groove extending off of the axial path.