[98532]
A chronic obstructive pulmonary disease pt placed on pulmonex xenon system for nuclear medicine lung ventilation - perfusion scan. With re-breathing as per machine, pt decompensated and needed to be removed from the machine. He revived after removal from the machine. The machine appeared to be working properly. The concern is expressed as a design flaw in conjunction with test protocol. Rptr writes, "i have identified significant risks i believe to be associated with the following three items: 1. Our pulmonex xenon system, model no. 130-500, mfg by atomic products corp causes decreases of oxygen saturation on all subjects, inspired oxygen decreases frequently, and carbon dioxide levels steadily increase to dangerous levels. Any one of these factors is dangerous. 2. The procedure we use calls for 6 mins. Of "wash-in" phase imaging which is dangerous as oxygen saturation and inspired oxygen levels have been observed to both decrease after only a single-breath on "wash-in" or equilibrium imaging. 3. This procedure used in conjuction with this machine dramatically increases or multiplies the danger of performing lung ventilation scans. The shortcomings of this machine are as follows: 1. The soda lime carbon dioxide absorber is not sufficient to extract carbon dioxide out of the rebreathing loop so that pts are rebreathing their own carbon dioxide which increases steadily to dangerous levels. 2. The system does not allow a continuous feed of oxygen nor does it allow you to titrate the flow of oxygen to the pt. 3. The system does not have an oxygen sensor for inspired oxygen or a carbon dioxide sensor for exhaled/inhaled carbon dioxide so that the technologist does not know what the levels are during a study. 4. The volume of the inhaled and exhalation bladder bags is only 1-2 liters which is insufficient to provide a safe closed rebreathing study as this is anologous to putting your head in a plastic bag with only 1-2 liters of available air to breath. 5. The system does not safely or adequately vent the volume of air as oxygen is added so that the pressure increases as more oxygen is added to this system, thereby causing pts to breath against resistance which can contribute to an exacerbation of the effects of all of the above risk factors. An untoward incident occurred involving a pt while performing a lung ventilation scan on may 6, 1997. " letter from rptr to risk manger states, "at your request i am providing you with reasons to perform lung ventilation scans by using dtpa aerosol and the aero/vent plus system or "technegas" instead of xe-133 being administered by closed rebreathing systems. The reasons are as follows: 1. Oxygen saturation levels drop on all pts when placed on a closed rebreathing system. Significant drops in oxygen saturation have been observed after a single breath on our closed system. 2. The inspired oxygen level drops precipitously when monitored with an oxygen sensor and frequent addition of oxygen is needed. "
Patient Sequence No: 1, Text Type: D, B5