Surgical Hypothermia

Hypothermia might not even cross your mind when you think about having surgery. But it’s actually not unheard of in hospital operating rooms across the country – among children and adults.

When a person is under anesthesia, he or she loses the ability to regulate body temperature. This means that his or her body temperature mirrors that of the room. If the body cools down so much as to lead to mild hypothermia, this restricts the movement of white blood cells, which are important for fighting off bacteria. If white blood cells can’t travel where they need to, this increases the chance of a surgical site infection.

The staff at Nationwide Children’s has been implementing various interventions to eliminate the occurrence of mild hypothermia. Some of these include warming the operating room before the patient arrives and maintaining it during the procedure, using warming blankets during travel and warming the mattress that patients lie on during the operation.

Listen in as Dr. Tom Taghon, director for Anesthesia Services, and Mike Fetzer, quality service line coordinator for Perioperative Services, talk specifics on how Nationwide Children’s Hospital is combating the cases of mild hypothermia, and how this is improving overall quality of care.

Transcript

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Rick McClead: Several research studies have demonstrated that various complications developed when surgery patients become cold while in the operating room. Surgical wound infection, increase surgical blood loss, cardiac arrhythmia, and prolonged post-operative hospitalization to name just a few, yet the operating rooms are really cold. What was being done to keep the kids warm while they’re in the operating room. Mild surgical hypothermia, next on Children’s on Quality.

[Music]

Welcome on Children’s on Quality. With me to discuss the problem in surgical hypothermia is Dr. Tom Taghon, Quality Director for Anesthesia Services at Nationwide Children’s Hospital. And Mike Fetzer, Quality Service Line Coordinator for Perioperative Services. Welcome to Children’s on Quality.

Dr. Tom Taghon: Thank you. It’s a pleasure to be here.

Mike Fetzer: Thank you.

01:00

Rick McClead: Dr. Taghon, I’d like to begin with you for our listeners. Please describe what we are talking about when we discuss hypothermia as a complication of surgery?

Tom Taghon: Sure. General anesthetics decrease your ability to maintain body temperatures. So, you essentially become poikilothermic, which is just a term that means you assume the temperature of the environment that you’re in. So, if we don’t take precautions to keep that room warm, and keep our patients warm, they will assume a very cold temperature during the case.

Rick McClead: And what kind of temperature ranges are we talking about?

Tom Taghon: So, we usually -our goal is to keep our patients above 36 degrees, between 36 and 38 degrees Celsius. So, we will take whatever precautions we need to maintain that range.

Rick McClead: Normal body temperature is 37..

Tom Taghon: 37.

Rick McClead: or 98.6. So, a degree or so on each side of that is what we’re looking at for a normal temperature.

Tom Taghon: That’s correct.

Rick McClead: What we’re not talking about is therapeutic hypothermia, correct?

Tom Taghon: You’re correct we are not. In this case is we’re taking advantage of hypothermia for its neuro protective and cardio protective effects.

02:06

And quite often in the cardiac case we have a profusionist there who can regulate the body temperature very precisely, so they can warm those patients up at the end of the case.

Rick McClead: Well, I commented in the intro that the operating rooms are really cold. Why are they so cold?

Tom Taghon: That’s a great question. I think we like to say that perhaps being cold will inhibit bacterial growth. But I think it’s also a function of comfort for the staff, surgeons, and scrub nurses are typically wearing heavy gowns and gets very hot in those lights.

Rick McClead: Well, in the opening I mentioned a few of the complications that describe in the literature that result from mild surgical hypothermia, however most of the literature is based on adult experiences. What do we see in kids? What do we need to be concerned about with our children in the operating room?

Tom Taghon: Well, many of the same things like we’re concerned about surgical site infection for example. We’re concern about thermal discomfort in the recovery room. If you ask adults, if they were to rank their discomfort in the recovery room, they will frequently rate thermal discomfort, or the discomfort from being cold even over their incisional pain.

03:08

So, we don’t want our kids certainly to suffer through that. And as you mentioned there are issues with blood clotting. So, we certainly can’t see the same complications in children, although the risk the data are not as strong.

Rick McClead: Well, one of the complications that’s been noted primarily in the adult literatures is the issue of post-operative shivering due to hypothermia and how that can increase the risk of mal-cardio schema or heart attacks. That’s not I think we need to worry about the kids isn’t it?

Tom Taghon: Typically not, Rick. It’s true that when you shiver you can increase your mild cardio oxygen consumption by sometimes up to 200%. Many of our children do not have coronary heart diseases, so they may not be at the same risk level for that. But there are other complications that we need to prevent.

Rick McClead: Are the kids more likely to have complications from their surgical hypothermia than an adult?

04:02

Tom Taghon: I don’t know if they are more likely. But I think they are certainly at the same risk.

Rick McClead: What kind of factors play into a child becoming hypothermic as far as what characteristics do they have physically that might contribute to them getting cold easily?

Tom Taghon: Well, I think that the biggest thing is, as you know they have a very high surface area to weight ratio which leads them to have a lot of exposed surface area. Because again as I mentioned before, the changes that occur due to the anesthetic, they can’t regulate their body temperature at all.

Rick McClead: Well, Mike Fetzer, before you explain how mild hypothermia came on the quality radar screen, would you share with our listeners a little bit about your background. Because you’re not a clinician, and yet you’re involved in the quality of health care at Nationwide Children’s Hospital. Tell us a little bit about that.

Mike Fetzer: Yeah, that’s true. I have a non-clinical background. Actually I have a degree in Industrial and Systems Engineering. And I worked for several years as a quality manager in a manufacturing setting. But currently I’m working as the Improvement Coordinator in our perioperative are and also in pediatric surgeries.

05:03

And what I do is I facilitate our teams with the use of improvement methodology, so we can move quality improvement projects forward. We work very closely with physicians, nurses, and leaders in those areas to facilitate those teams.

This particular project of -got on the quality radar screen as were looking at surgical site infections, and how we could try to reduce our surgical site infections, specific population. And we saw that there was an opportunity for us to decrease hypothermia in the OR.

Rick McClead: So, there is this relationship between this model hypothermia and possible wound infections developing after surgery in at least some populations of patients.

Tom, can you explain how mild hypothermia could increase the risk of wound infection or surgical site infection?

Tom Taghon: Yeah. It’s an interesting question. That the leading theory is that when you get hypothermic, you actually develop some basal constriction in the subcutaneous tissues.

06:04

And what that does is decrease oxygen delivery to those tissues and that inhibits the function of neutrophils which can kill organisms using oxydated mechanism. So, if you interfere with that mechanism of white blood cells, and neutrophils, you can increase the risk of your infection.

Rick McClead: So, the white cells won’t gobble up the bacteria very well?

Tom Taghon: That’s correct.

Rick McClead: So, we need to set about minimizing this mild hypothermia? Michael, what was your approach to do that?

Mike Fetzer: Well, initially we brought a team together, and we wanted to determine our baseline of hypothermia. Well, in doing so, we found that our ability to measure temperature following surgery was quite variable and it was quite inconsistent.

So, therefore we had to improve our ability to capture an accurate temperature following surgery. So, we did this by introducing new digital thermometers for use in the PAC-U, and this really resolved our issue with variability, and inconsistency as it related to capturing the correct temperature following surgery.

07:06

Rick McClead: The PAC-U is the Post Anesthesia Care Unit, that’s where a patient will go after they’ve been taken out of the operating room to recover from surgery. It’s still a recovery room?

Mike Fetzer: Yes. That is correct. And then once we corrected our gauge error if you will, we were then able to understand our true baseline and really start focusing on reducing hypothermia. We were able then to analyze our data using quality improvement tools such as Pareto diagrams and honing in on the largest portion of hypothermia based on the population of patients that we see in the operating room.

Rick McClead: And what was that?

Mike Fetzer: It was really with the kids that were having orthopedic surgeries. Surprisingly it was a group of teenagers.

Rick McClead: It was the older kid population?

Mike Fetzer: Yes.

Rick McClead: And that surprise me. Why do you think Tom, the older kids seemed to be having more of a problem in this than the babies?

08:06

Tom Taghon: So, we were surprised by that. And we fully expected to see a higher instances in the young children because of that surface area, it’s the body weight ratio that we discussed. But what we suspect is that we were very attuned to the possibility of hypothermia in young infants and children, and it maybe a little lax in our approach to the older children. And I think that was reflected in our data.

Rick McClead: OK. All right. So, you defined the population of patients you really needs to target to get their risk for developing hypothermia during surgery. So, what was your next step?

Mike Fetzer: Well, we then wanted to try some different interventions to see if we could effectively reduce hypothermia. And some of the interventions that we tried, we started with the variation of temperature management bundle. Those included certain devices that are used in the operating room to keep patients warm.

09:00

We also looked at room temperature, we looked at the use of various different blankets throughout the perioperative travel. We considered using warm fluids for specific cases. We also worked with our pre-operative technicians to ask them to change their process, so they could place warming devices in the OR pre-operatively.

Therefore making it easier for the staff in the OR to use those devices. We’ve also considered perioperative warming gowns. So, this were some of the ideas and interventions that we tried.

Rick McClead: All improvement involves change, but not all changes in improvement. So, those various interventions that you listed, which were the ones that you think seemed to make a big difference, Tom?

Tom Taghon: So, I think Max surprisingly we found that warming the room before the patient arrives and maintaining the room at a very warm temperature until the time that the patient is draped was one of the key interventions that helped. And it’s a pretty basic thing, but we were able to show that through our PDSA cycle and show that, that was very effective.

10:09

We also found that the use of the bear hugger routinely which is a force the air warming device we use in the operating room, it’s kind of like a big hair dryer, but the warm air goes into a mattress that the child lays down, or we can place over them as a blanket.

That device was very effective. And then again, warming the room up at the end of the case before we take the drapes off of the patient. And what I think was really needed about this project is those are all simple interventions.

They are all things that we know work, but when we’re able to put them together as bundle and eliminate the variability in our practice, we saw good results.

Rick McClead: That’s interesting though that both of the intervention before warming up the OR and the intervention at the end allowing it to return to those temperatures, that’s all occurring at a time when the staff is not likely to be fully gowned and where they’re going to be uncomfortable.

11:04

Tom Taghon: That’s right.

Rick McClead: Beginning of the case, and they haven’t really gowned up yet, and at the end of the case, they’re taking all the gowns off?

Tom Taghon: Right. That’s a good point and that’s correct. And as we mentioned before one of the reasons the rooms are cool I think is for the comfort of the staff. And so, sometimes when the staff -when they feel particularly warm, we like to point out that if we’re good before the case and at the end of the case we can cool there off in the middle and still keep the patient warm.

Rick McClead: That’s interesting. What do you think the next steps are for this particular project?

Tom Taghon: Well, I think most importantly we’ve made some gains, we’ve decreased our incidents of hypothermia by about half, and we’d like to maintain that.. So, we’re sort of in a maintenance mode there and we really want to hold those gains.

And secondly, we’d like to get to zero percent hypothermia, so we’re trying to identify those children that were still struggling with and seeing if there’s any trends there. And we’d identified a few that we’re going to go after and try to target some interventions to those populations.

12:03

Rick McClead: Do you have thoughts at this point as to why some children are just more difficult to maintain normal thermic during the operating?

Tom Taghon: Certainly. You know, I think there are some children who I think have neurological conditions that probably diminish their ability to maintain their body temperature without anesthesia. So, if we can identify those children perioperatively and start actively warming them before they even come to the operating room, we might be able to make some gains there. And so, that’s one of our trials right now that we are using some gowns that we can actually start actively warming children before they come to the OR.

Rick McClead: Well, we are out of time for this edition of Children’s on Quality. I thank my guest Dr. Tom Taghon, and Mike Fetzer. I also thank my listeners. Children’s on Quality is produces by Kelly Nightingale. Our theme music was composed by Ryan McClead. Next time on Children’s on Quality, we hope to finally bring you our podcast on the luminating arm at Nationwide Children’s Hospital.

13:03

Until then, this is your host, Dr. Rick McClead wishing you the best of good health.

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