Reducing risk from heater-cooler devices

We now know that heater-cooler devices (HCDs) are capable of producing bio-aerosols in the operating room (OR), and that these bio-aerosols can cause devastating infections. Obviously these devices must be re-engineered to eliminate bio-aerosol production, or replaced with other approaches to regulate the temperature of cardiopulmonary bypass machines and cardioplegia solutions. Until then, temporizing measures to eliminate risk from these faulty devices are needed. 

We’ve already discussed our approach to removal of HCDs from the OR, and the approach they’ve used in Zurich (encasing the HCD in a stainless steel housing and venting the exhaust outside of the OR). At SHEA and ECCMID I saw interesting descriptions of two other approaches to separate the HCD exhaust from OR air.

First, at SHEA a group from Boston Children’s Hospital presented a “Wall Water System” that takes advantage of ready availability of hot and cold water supplies near to the OR, combined with a medical grade mixing valve to carefully regulate temperature. This allowed them to provide heating and cooling without the need for an HCD. An ECCMID attendee noted that this approach has also been initiated at one or more hospitals in Europe. See the image below for the full poster (sorry for image quality, it’s my own iPhone pic!). 

At ECCMID, John Conly from Calgary presented their experience with contaminated HCDs, and their approach to placement of the HCD within an enclosure that included the OR exhaust vent that was drawing the HCD exhaust out of the OR. Their poster is below. 

I’m most intrigued by the first approach: using existing hot and cold water supplies, along with precision mixing valves, to eliminate the need for a free-standing unit in the OR that exists solely to regulate the temperature of a water reservoir.