According to one embodiment, a method includes positioning a trocar having a pressure sensor in or on the trocar into a patient cavity such that distension of the patient cavity causes an altitude of the pressure sensor to increase. The method also includes distending the patient cavity by supplying an insufflation gas to the patient cavity, thereby increasing an altitude of the pressure sensor from a first altitude to a second altitude. The method also includes determining a change in pressure at the pressure sensor resulting from increasing the altitude of the pressure sensor from the first altitude to the second altitude and controlling the supply of insufflation gas to the patient cavity in response to the determined change in pressure resulting from increasing the altitude of the pressure sensor from the first altitude to the second altitude.