Heater/Cooler Survey Results are In!


FA 2016

Editor’s Note:


I started this survey back in the Fall of last year.

(Click image above to view or take the survey)

Since then I have been at 4 other institutions and have had the opportunity to observe how my colleagues addressed this issue.  No footprint changes regarding the relative position of the HC to the patient and ECC were engaged.  

At some institutions, blankets or sterile drapes were placed to partially blunt the exhaust vent of the HC.  

(This probably works a little bit better than holding your breath?)

In one case, effort was made to rotate the HC in order to steer the exhaust vent gasses away from the surgical field.  Probably the most effective effort that I have seen in terms of mitigating gross exposure to the patient.

In ALL cases, cleaning schedules were much accelerated, and testing of the pH of the HC water was pretty much universal.  All institutions deployed Hydrogen Peroxide into the HC water.  The time between cleaning intervals was reduced, often at least once or twice a week, and in one case, almost every day (anticipating a low case-load and long interval between cases), leaving the HC empty and the lines drained and unattached.  

I’m not sure as to the efficacy of that particular practice (almost-daily draining of HC and disconnected H2O lines) as it obviously doesn’t remove all water residing in the HC or the water lines for that matter, and two of the three mediums prerequisite for bacterial growth (moisture and lack of light) were still in play.  If sterility was a functional component for this approach, it was obviated by the fact that the lines used to drain and refill the HC were reused consistently and not sterile, while bleach or some other bactericidal agent were never used.  In my opinion, the best you can hope for when cleaning a HC is just that- CLEAN but NOT STERILE.  You can use all the sterile tubing and H2O filters you want, but at some point, it will remain a clean, yet contaminated environment.

From a clinical perspective, (when leaving a an HC completely drained) the price to be paid here is the fact that the first thing you have to do when starting a case emergently, is to fill the HC and attach water lines to their appropriate devices.  That process consumes precious time, and is unnecessarily cumbersome and stressful.

What this demonstrates to me, is that going through the motions, and perhaps over reacting is potentially more hazardous than whatever nosocomial infection you are trying to avoid.  It’s about as crazy as having your HC placed in the hallway outside of the heart room.  (Sorry if I have offended anyone with these statements, but simply going through the motions without thinking it through is a complete waste of time.  Just my opinion) 🙂

A point of observation- since one particular HC has been isolated as a common denominator (whether based on true science or not- the association cannot be ignored), this is the only system I have used that has an overflow canister, that indeed overflows if you are employing a heating blanket, and turn off Q to that banket without clamping the lines distal to the HC outlet/inlet.  I’m sure it’s coincidental, but the back flow from the heating blanket is an obvious design flaw and very messy.

Obviously, this survey is not scientific.  But that doesn’t really matter here, as Science at this point is unable to afford us a reasonable solution and conclusion as to the mechanism of and delivery of this pathogen to the patient, and ways to counter those mechanisms.  We can speculate and surmise quite a bit, and yet prove nothing.  So common sense has it’s place here in this forum 🙂  

This survey was designed to solicit the opinions of the professionals that employ these devices on a daily basis to engage CPB.  I can think of no other professionals better suited to solicit opinions from than this forum of Perfusionists.  I’m not really interested in governing bodies,or designated “perfusion gurus” mandating a policy or approach here, as that clearly hasn’t happened.  What I would like to see, is clarity of approach and a logical progression to action resulting in positive outcomes that unfortunately won’t be measurable for quite a few years.

Thank you in advance for all of your input.

Please note:  The comments at the end of this article are very cogent and worth reading 🙂

I’ll leave it to you to draw your own conclusions from the data sets below, in my opinion, HC gas exhaust represents just one of the multiple sources of hazards that patients and staff alike must face in the OR:

  • Vent exhaust
  • Potential rupture of compressed O2/CO2 cylinders
  • Volatile Anesthetic gases
  • Inhaled surgical smoke (Kudos to Specialty Care for delivering a training module on Surgical smoke that I just read yesterday- very enlightening and honestly something I had never really considered before).
  • Accidental staff exposure to HIV, Hep C, Hep B, TB, MRSA, Viruses, etc.
  • VERY significant lapses in sterile technique at the surgical field (see below)


The Survey was divided into four sub groupings of questions:

  • Device Related Questions
  • Clinical Q & A
  • Potential Protocol Adjustments
  • Institutional approaches to dealing with the issue

Enjoy 🙂




Understanding & Addressing the Problem



Comments to the Question:

What More would You Like to know About Laminar Flow- and How it Protects the Sterile Field?

  • I guess I’m just not sure of the physics with it?
  • It’s extend throughout the OR and interdependencies between the different devices and tables and their effect of disturbing the laminar flow field
  • Yes
  • Based on recent FDA/CDC conference call I’m not sure Laminar flow is the answer
  • No
  • N/A
  • How is it working ? What is it efficient ? Is really useful ?
  • Laminar flow is but one part of the equation. Other aspects include location of H/C devices, HLMs, Staff positions and limiting traffic into and out of the surgical arena. Other variables include adherence to aseptic technique by the entire team without exceptions and scheduled terminal cleanings by environmental services.
  • None
  • Pore size
  • How can laminar flow overcome the fan output of the HT3
  • Nothing
  • Current evidence
  • Keep the HC air exhaust away from sterile field
  • Stop The particular circulation in O.R anda take offers from O.R
  • About steril field
  • One way to take out particular form O.R

Problem Solving & Possible Solutions


Evaluating Efficacy of Implemented Changes


47% Monitor HCD for bacterial growth through heterotrophic plate count (HPC), pseudomonas, and coliform bacteria, based on hospital infectious disease recommendations.
25% Reduce open entry points on oxygenator venous reservoirs by closing all luer ports not necessary for venting, and omit the use of syringes as “funnels” for the delivery of solutions either during priming of the circuit or throughout the case.
37% Where possible, position heart-lung machine in the laminar flow area of the OR table.
22% Limit turning on HCD to the times when needed.
17% Position HCD at the end of the OR bed at patient’s feet.
15% Do not empty tubing attaching HCD to heat exchanger(s) until AFTER the patient has left the OR.
29% Use gas evacuation system to capture air circulated at the HCD exhaust fan into hospital waste system.
6% Omit the use of non-disposable mounting system (holders) for oxygenators and cardioplegia heat exchange couplers.
44% At regular disinfection and cleaning cycles sterilize quick-disconnects (Hansen Couplers) according to hospital policy for instrumentation.
22% Consider an alternate location of HCD outside of the OR.
26% Place HCD in encased housing.
12% When system is in use, place blanket over exhaust area of HCD, assuring that the device does not malfunction by limiting exhaust and over-heating.
30% Use Sterilization by Filtration for H2O Utilized in H/C
28% Use Sterilized H2O for H/C
6% Other

Relevancy of the Problem (Putting it into Perspective)


30.10% Gowning & Gloving
20.40% Poor Closed Gloving Technique
24.30% Casual Discard of Surgical Mask Once the Patient is “Closed”
32% Hands Below the Waist at the Surgical Field
33% Pouring of Solutions to Containers on the Back Table
22.30% The Anesthesia Screen
9.70% Line Placement (Arterial)
10.70% Line Placement (Schwann)
35% Blood Spraying to Face, Mask, or upper Chest Area- and not Changing Scrubs (Circ Nurse- Wiping Off Mask)
17.50% Transfer of Perfusion Lines to the Field
47.60% Suction Lines or Cell Saver Lines, Drifting off the Edge of the Field, below the Waist, and Being Pulled Up Again
5.80% Platelet Gel Transfer both to the Bowl, Aspirated from the Bowl, and Delivered to the Filed
19.40% Perfusion Connections When Setting up a Circuit
21.40% Modifying the ECC- cutting in a line
6.80% Adding a StopCock while on bypass
11.70% Modifying the ECC while on Bypass
29.10% Using a 60 cc Syringe as a “funnel” for delivering Meds to the Reservoir
7.80% Adding Meds- via Syringe to a Prime Bag
39.80% Staff Personnel Involved in the Operation When They are Clearly Ill or Coughing Extensively
10.70% Other

Comments to the Question: 

Please Describe How Your Institution Has Addressed this Issue?

  1. Depend on hospital
  2. Complying with manufacturers guidelines.
  3. NA
  4. Cleaning protocol and competencies for staff.
  5. Monthly disinfection and water change out
  6. Daily changes of the water in the HCU. weekly disinfection as advised by the manufacturer
  7. Developed cleaning protocol
  8. Implementing cleaning protocols
  9. Regular taking cultures of the water inside the HCD cleaning it regular and leaving some chlorine in the water
  10. Infection control protocols active for years. Common sense. Quality control… standard practices
  11. We follow the recommendations from Sorin. Have submitted for new HCDs but hospital won’t budge since there in no “recall” from Sorin.
  12. None. Except carry out disinfection of the HCD. However, the disinfection protocol suggested by Manufacturer is different from US. Disinfection (by Chlorox) needed to be done every 3 months only.
  13. We have implemented an action plan for regular cleaning and disinfection of the HC device. We also limit the time the HC is in use to times when it is critical for patient care. HC is already located at the patients feet in all ORs.
  14. We started disinfecting machines according to manufacturers recommendations and started logging cleaning intervals. Monthly water testing and corrective action plan. Adding which HC was used in patients perfusion record giving traceability.
  15. Weekly bleach/peroxide cleaning
  16. Following IFU’s for cleaning and maintenance and implementing a culture monitoring program
  17. They haven’t
  18. communication to all hospital staff, implement mfg IFUs, document equipment cleaning and use
  19. Location of HC’s and exbaust; filtration and sterilization; proper water line tubing.
  20. disinfection and cleaning cycles
  21. By following manufactures protocol. Applying vacuum to exhaust fan. Positioning hcu next to OR return duct. Sterile overflow bottles weekly.
  22. They have not any idea for this issue
  23. Followed manufacturer
  24. Using newer units and replacing old ones
  25. Purchasing HC’s that do not have inaccessible air-water interface.
  26. We have ice machine and water source that is .2 micron filtered, we now follow cleaning protocol and cleaning products per manufacturers information for use.
  27. Looking into alternative HC machines. Addressing alternatives for limiting infection via current HC
  28. Removed 3t from service
  29. Instituting a regularly scheduled cleaning regimen, covering the exhaust fans path with blankets and keeping the H/C as far away from the operating field.
  30. Implemented protocols on HC water changes and disinfections
  31. Initially following manufacturers recommendations for cleaning. But have since pulled all 3Ts from use and have returned to utilizing Sorin Dual HCs.
  32. Regular cleaning of hcd
  33. Changing cleaning protocol, we used to boil the Heater coolers in the OR but we stopped that due to it likely creating further aerosolization. We do test the water for microbes. At this present time our infection control team doesn’t allow us to clean the heater coolers anywhere inside the entire hospital so it isn’t being done at all. We are in the process of trying to find a place or company to take them and clean them and return them back to us.
  34. Nothing
  35. Followed closely FDA field notices and implemented at all possible extension methods of HCD disinfection
  36. We have made our own protocol for this
  37. We do daily water changes with (tap H20+hydrogen peroxide) and weekly disinfection with Puristeril.The H/C are sampled weekly.We position the machines at the feet of the patient,with the tubings facing the wall,not the patient and we never make connections or disconnections if the patient is in theatre
  38. Follow mfg/FDA based recommendations
  39. Just have a meeting with microbiologist infectious control team and the manufacturer to have an understanding and make every perfusionist strictly follow the protocols on dealing with the HC device in order to mininizeed the risk of patient s infected
  40. I can see development abort this issue
  41. Bought all new HCD’s. Culture water. Developing air evacuation housing.
  42. Following manufacturers cleaning protocols. Replacing HCU with a different one.
  43. We are following the manufacturers protocols and investigating other ideas such as exhaust fan venting to outside the room
  44. Beginner

Comments to the Question: 

Do You Have Any Suggestions for Other Options?

  1. Please check surgeons for contaminations
  2. Clean up the bacteria in the main water supply. Everyone who washes their hands exposes themselves and patient to bacteria. This is an easy scapegoat blaming HC’s for a much broader problem.
  3. No
  4. Anti Microbial Therapy- Find a way to eliminate this pathogen
  5. Place HCU as far from the patient as possible, check for other sources, i.e. Water supply, air conditioning, alternate sources.
  6. Clean more often, change lines more often
  7. Unfortunately, the 3T design makes it almost impossible to adequately clean. Based on what I have read and heard from the CDC and FDA there is no 100% effective way to clean the 3T. Units should be taken out of service and refunds provided to customers. This was an unintended consequence of their design but a consequence nonetheless. No other heater coolers have been implicated in the direct transmission of infection to patients.
  8. NA
  9. every day disinfection whit additive solution or cps in HC, and periodic disinfection and cleaning cycles
  10. I wonder if h/c water has been changed routinely every week , can We decrease risk ?
  11. Studies should be done
  12. Use a device that does not have inaccessible air-water interface.
  13. Industry needs to look into in-line UV lights to help kill bacteria. It is used successfully in fish aquarium filtration systems and I would think it might be a benefit in perfusion heater-coolers.
  14. scavenging the fan area…. continuing to change and sterilize with new water/bleach. Not sure what new HC will be with infection.
  15. Don’t purchase a 3t
  16. We need to start culturing H/C water samples routinely to determine the efficacy of our cleaning regimen.
  17. Rigorous and regimented cleaning
  18. Nkne
  19. CCompletely new methods need to be developed
  20. Research is required as a lot is unknown on Mycobacterium contamination
  21. Waiting to publish in artikel