A Cart To Provide High Frequency Jet Ventilation during Transport of Neonates

Abstract

We report the evaluation of a cart we created to provide high frequency jet ventilation (HFJV) to neonates during intrahospital or interhospital transport. DESCRIPTION: The cart carries a conventional ventilator, jet ventilator (JV), incubator, gas blender, 3 E cylinders of oxygen and 2 of air, uninterruptible electric power supply (UPS), 2 syringe infusion pumps, cardiac monitor, and oximeter. EVALUATION METHODS: To determine the available operating time of the ventilators, we ran tests with 60% and 100% oxygen, high and low ventilator settings, 2.5-mm and 3.5-mm endotracheal tubes, and lung simulator set for low and high time constants. With five different combinations of these variables, the system was run to exhaustion of its gas supply. To determine the operating time limit of the UPS, we used it to operate the JV until the low-battery alarm sounded. RESULTS: The UPS always provided electrical power for at least 2 hours. In no case did a single cylinder of oxygen fail to power the system for less than 20 min. Because the cart carries 3 cylinders of oxygen and 2 of air, under the conditions tested a minimum of 60 min of continuous operation, using 100% oxygen, should be available during those portions of transports when the system is away from hospital and ambulance bulk power sources and is dependent on its own UPS and E cylinders of gas. EXPERIENCE: We have used the cart on two occasions to transport a 30-week gestational age, 1-kg, HFJV-dependent infant, first from ICU to surgery, then to another hospital for cardiac catheterization. Total transport time was 3 hours; there were no problems. The cart has also been used to transport three patients between hospitals during ECMO, without HFJV. CONCLUSIONS: Our HFJV transport system is adequate to transport an HFJV-dependent infant during the 30 to 60 minutes that may elapse when the cart is away from ambulance or hospital sources of electricity and gas. Available operating time with an HFJV transport system should be estimated conservatively; when an infant is dependent on HFJV, it would be well to have aircraft backup in case of ambulance breakdown or other contingencies.