A single step body insertion device comprises a cannula and a Veress needle which penetrates the skin surface and relevant tissue layers to reach fluid and/or gases that need to be removed from the body. The cannula shaft and tapered tip are of a polymeric material which is flexible and kink resistant. The Veress needle has an engagement feature for engagement with the tapered tip of the cannula for delivery of the cannula into the body as the Veress needle is inserted into the body. The device is used for the management of conditions such as pneumothoraxes and pleural effusions as well as other conditions that require release of fluid and/or gas from the body.