A few cases at a time, the M. chimaera outbreak associated with heater cooler units continues to grow. For reasons unclear to me, the response from CDC and FDA to this train wreck in slow motion has been underwhelming. We continue to field calls from hospitals struggling to deal with an approach to the outbreak. On today’s IDSA list-serv (IDea Exchange) Dr. Luther Rhodes wrote: “The silence is deafening. I call on those physicians with hands on experience in evaluating post open heart patients referred to ID for evaluation of concerns, signs or symptoms of possible NTM infection to speak up loudly and clearly. Lessons learned, protocols developed, evaluation and testing tools learned dealing with large scale regional patient notification should in my opinion be shared…”
We have posted several times on this topic, but I thought it might be useful to summarize how a hospital could approach this problem in a single post. To view older posts, type chimaera in the search box in the top right hand corner of your display.
Step 1: Determination of risk
Whether you have seen a case or not, the first question is whether your hospital has used the LivaNova Sorin T3 heater cooler unit (HCU) in the last six years. If the answer is no, there is no immediate action you need to take. If yes, then the investigation begins, as you must assume the units are contaminated,
regardless of the manufacturing date.
Step 2: Risk mitigation
If you are currently using the LivaNova (Sorin) T3 unit, the
most important risk mitigation strategy is to get the units out of the operating room. The molecular epidemiology clearly points to contamination of the HCUs at the manufacturing facility, which allows the units to produce an infectious bioaerosol that contaminates the operative field. Separation of this bioaerosol from the operative field is the key to eliminating the risk. Why the FDA won’t clearly state this is very puzzling.
At the University of Iowa Hospitals and Clinics our engineers were able to quickly (within a few days) devise a solution by creating a 6” x 6” hole (see photos) through the operating room wall on the semi-restricted side of the room. The area identified for creation of this portal was determined by hose access to the OR table with minimal interference with staff and equipment; access to power; and the ability to leave proper corridor width per life safety code. Testing demonstrated that positive pressure was able to be maintained in the OR after creation of the portal. The portal itself with a sliding door was constructed of Corian in some cases and stainless steel in others. A hose protection mat was placed in the ORs to protect the HCU hoses and to provide a ramp effect for equipment to be relocated as needed during the cases. One advantage of the T3 HCU is that remotes can be purchased that allow the perfusionist in the OR to control the HCU located outside of the room. Once the HCUs were moved out of the OR, we demonstrated no difficulty with appropriate heating or cooling. Remember, given the long incubation and detection period of these infections (maximum 6 years to date), if you do not eliminate the risk now, you will likely be chasing cases for many years with no end in sight.

