A gas conditioning unit for a surgical gas delivery device is disclosed, which includes a filter housing having an insufflation gas flow path for delivering insufflation gas to a body cavity and for facilitating pressure measurements from the body cavity, a pressurized gas flow path for delivering pressurized gas from a pump in the surgical gas delivery device to an internal nozzle in the filter housing that accelerates the pressurized gas and thereby generates a continuous pressure barrier that inhibits egress of insufflation gas from the body cavity, a vacuum return flow path for returning depressurized gas spent by the internal nozzle back to the pump under vacuum, an air entrainment flow path for drawing air into the body cavity to maintain a given pressure therein, and a smoke evacuation flow path for conveying smoke from the body cavity.