CPB FMEA #3: Heat exchanger leak in the oxygenator or cardioplegia heat exchanger.
This week’s FEMA is prompted by the recent chatter on the list servers about cleaning heater/coolers (H/C). The discussion centered on two aspects: 1) how to clean the water reservoir to kill microbial contamination without damaging the equipment and 2) addressing the rumored Joint Commission focus on standing water reservoirs in the OR which could be the source of splash contamination. I am assuming this would include mop buckets, wet vacs and warming blankets. But it could also include H/C reservoirs as well.
One thing I did not see discussed on the list servers was the potential of an H/C to injure or kill a patient as a result of a heat exchanger (HE) leak. I fear that this represents a lackadaisical, even cavalier, attitude on the part of some in the perfusion community towards the risk of a HE leak. Over the last decade I have noticed that some students rotating through my program were not well educated on the need to water test the HE, let alone how to deal with a life threatening HE leak.
Quality control for oxygenators and cardioplegia sets has greatly improved over the years. And I have not seen a HE leak in probably 20+ years. But that should not equate to an “out of sight, out of mind” mindset. There are probably many programs with staff perfusionists so young that they are not actively cognizant of HE leak possibility.
This FMEA is an excellent example of providing institutional memory of a rare failure. Of the six perfusionists at my former employer, I think I was the only one who had ever seen a HE leak on CPB or dealt with a patient exposed to a leak. Next to me, the most experienced staff perfusionist had only 15 years in practice, never having seen a leak. After I retired, the program’s FMEA was the only thing to remind the staff that an H/E leak was a risk.
I do not know the frequency of HE leaks. It is very rare. But it is not something to dismiss because the consequences for the patient can be devastating. This British perfusion web page has four recent case reports of HE leaks; three while on CPB:
<http://www.scps.org.uk/index.php?option=com_content&task=view&id=218&Itemid=79>