Mild perioperative core hypothermia is common in patients undergoing colon surgery. Hypothermia leads to vasoconstriction and decreased oxygen tension at the wound site, to impaired neutrophil function and also, potentially, to decreased wound strength. This randomized, double-blind study was undertaken to determine whether maintaining perioperative normothermia would decrease infections, improve wound healing and decrease length of stay in patients undergoing colon resection.
Patients were randomized to normothermia (core temperature maintained
at about 36.5 degrees Centigrade) or hypothermia (allowed to drop to about
34.5). In both groups, IV fluids passed through a warming device and forced
air was circulated over the patients' upper body, but in the normothermia
group the devices were turned on, in the hypothermia group the fluid warmer
was not turned on and the air was not heated. The authors state that the
surgeons were not able to detect whether the patients were being warmed
The authors planned to enroll 400 patients but also to perform interim analyses after the enrollment of 200 and 300 patients, with appropriately stringent criteria for early termination of the trial.
Similarly, these results apply to colorectal resection surgery. Although it seems logical that they should apply to other types of surgery, some further trials will need to be done to confirm this.
As the authors and the authors of an accompanying editorial note, the risk of infection associated with smoking is even greater than the risk of hypothermia. It would be interesting to determine whether this is due to the vasoconstrictive effect of smoking, in which case discontinuing the habit a day or two prior to surgery would be of significant utility.
These points aside, this is a very well-designed study, with results that are both statistically and clinically significant. It is all the more impressive for its use of a low-cost, low-tech approach. It will be interesting to see how quickly these results will be translated into practice.
May 25, 1996
Date: Sat, 01 Jun 1996
From: Olafur Jakobsson <firstname.lastname@example.org>
Once again 'a feeling', but I strongly believe that the principles of adequate hydration, pain relief and normal body temperature have a significant influence on the results of free-flap surgery. The results are very dependent upon peripheral skin circulation, which otherwise can be difficult to maintain.
O P Jakobsson, MD, PhD, plastic surgeon
Yes, as free-flap operations tend to take a long time with a large part of the body exposed. We certainly had problems until this was recognized and solved.
Date: 27 Jun 96
From: Daniel Sessler <76735.2602@CompuServe.COM>
To: Michael Jacobson
Thank you for including our recent NEJM article on your WWW site. Your summary is excellent and I have nothing to add to it. I would be pleased to respond to readers' questions.
September 5, 1996
Letters to the Editor about this article from the NEJM website.
December 3, 1996
What do you think of using normovolemic hemodilution to lessen the possibility of infection?
E. WENGER MD.
A quick literature search didn't turn up any obvious articles about how this technique affects wound infection rates, and I'm not sure how it would interact with perioperative normo- or hypothermia. I'll forward this question to Dr. Sessler, to see if he has anything to add. -- mj
Date: Mon, 21 Apr 1997 From: Arni Björnsson <email@example.com>
Arni Bjornsson MD, Dep of Anesthesiology
Univ. Hospital Linkoping
The question is highly relevant. We have an infection problem in our spinal surgery unit. The patients are hemodiluted to Hb 8.0 mg/dL, the drained volume being replaced with saline and 4% albumin in a ratio 1:2.
Most of the patients have hypothermia (35 deg. Celcius) at the end of surgery. We routinely use plasma sequestration, red cell salvage (Haemonetics AT-1000) and platelet gel to minimize the intraoperative blood loss. Proper antibiotic therapy and skilled surgeons give good results but still the infection rate (20%) and subsequent reoperations should be lower.
The theatre ventilation is being replaced and new routines in sterility are adapted. Still we can't keep the patients warm during these lengthy operations and I'm certain that is a contributing fact to the high infection rate.
Comments are welcome to:
June 12, 1997
The New England Journal of Medicine just published a detailed review
of the topic of perioperative hypothermia (N Engl J Med 336:1730-7) by
Dr. Daniel Sessler, corresponding author of this study.
Date: Fri, 20 Jun 1997
From: Frank Lloyd <firstname.lastname@example.org>
Wound infections can be treated on outpatient basis. So if wound infection is the cause of prolonged hosp stay, it may be associated with other factors.
Good study, although the ethics could be questioned, as was done.
Date: Tue, 19 Aug 1997
I would like to add that hotline fluid warming by itself fails to maintain normothermia. The claim by some physicians that fluid warming alone will maintain normothermia doesn’t agree with much of what is known about perioperative heat balance and seems inconsistent with the laws of thermodynamics.
E. Wenger MD
All I remember of the laws of thermodynamics is that entropy is constantly increasing, which the surface of my desk confirms daily. -- mj
From: Alo IPSS [email@example.com]
Sent: Tuesday, February 16, 1999
I think the article is very interesting, because for the general surgeon
hypothermia may not be so important, but for pediatric surgeon it is very
important. Perhaps it´s necesary to use
warm or radiant table in operatory room as in pediatric surgery for maintenance of normothermia.
José Cárdenas, M.D.- Pediatric Surgeon.
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