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The effect of heat and moisture exchanger on humidity and body temperature in a low-flow system

Johansson, Anders LU ; Lundberg, Dag LU and Luttropp, Hans-Henrik LU (2003) In Acta Anaesthesiol Scand 47(5). p.564-587
Abstract
Background: Artificial humidification of dry inspired gases seems to reduce the drop in body temperature during surgery. The aim of this study was to evaluate the humidity and temperature of anaesthetic gases with heat and moisture exchangers (HMEs). The secondary aim was to evaluate if HMEs in combination with low-flow anaesthesia could prevent a decrease in the body temperature during general anaesthesia.

Methods: Ninety patients scheduled for general surgery were randomised to receive a fresh gas flow of 1.0, 3.0 or 6.0 lmin1 with or without HMEs in a circle anaesthesia system. Relative humidity, absolute humidity, temperature of inspired gases and body temperatures were measured during 120 min of anaesthesia.

Results:... (More)
Background: Artificial humidification of dry inspired gases seems to reduce the drop in body temperature during surgery. The aim of this study was to evaluate the humidity and temperature of anaesthetic gases with heat and moisture exchangers (HMEs). The secondary aim was to evaluate if HMEs in combination with low-flow anaesthesia could prevent a decrease in the body temperature during general anaesthesia.

Methods: Ninety patients scheduled for general surgery were randomised to receive a fresh gas flow of 1.0, 3.0 or 6.0 lmin1 with or without HMEs in a circle anaesthesia system. Relative humidity, absolute humidity, temperature of inspired gases and body temperatures were measured during 120 min of anaesthesia.

Results: The inspiratory absolute humidity levels with HMEs were 32.73.1, 32.11.1 and 29.21.9mg H2O l1 and 26.62.3, 22.63.0 and 13.02.6mgH2O l1 without HMEs after 120 min of anaesthesia with 1.0, 3.0, or 6.0 l min1 fresh gas flows (P<0.05, between with and without HME). The relative humidity levels with HMEs were 93.83.3, 92.72.2

and 90.73.5%, and without the HMEs 95.24.5, 86.88.0 and 52.89.8% (P<0.05, between with and without HMEs in the 3.0 and 6.0 lmin1 groups). The inspiratory gas temperatures with HMEs were 32.52.0, 32.40.5 and 31.01.9C, and 28.41.5,27.10.8 and 26.10.6C without HMEs after 120 min of anaesthesia (P<0.05, between with and without HME). The tympanic membrane temperatures at 120 min of anaesthesia were

35.80.6, 35.50.6 and 35.40.8C in the groups with HMEs, and 35.80.6, 35.30.7 and 35.30.9C in the groups without the HMEs (NS).

Conclusions: The HMEs improved the inspiratory absolute humidity, relative humidity and temperature of the anaesthetic gases during different fresh gas flows. However, the HMEs were not able to prevent a body temperature drop during low-flow anaesthesia. (Less)
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published
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in
Acta Anaesthesiol Scand
volume
47
issue
5
pages
564 - 587
language
English
LU publication?
yes
id
21d0f484-d85a-4ee6-a77c-29ed9ff01b8b (old id 3513646)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/12699514
http://onlinelibrary.wiley.com/doi/10.1034/j.1399-6576.2003.00108.x/abstract
date added to LUP
2013-03-06 12:44:36
date last changed
2016-04-16 11:21:07
@article{21d0f484-d85a-4ee6-a77c-29ed9ff01b8b,
  abstract     = {Background: Artificial humidification of dry inspired gases seems to reduce the drop in body temperature during surgery. The aim of this study was to evaluate the humidity and temperature of anaesthetic gases with heat and moisture exchangers (HMEs). The secondary aim was to evaluate if HMEs in combination with low-flow anaesthesia could prevent a decrease in the body temperature during general anaesthesia.<br/><br>
Methods: Ninety patients scheduled for general surgery were randomised to receive a fresh gas flow of 1.0, 3.0 or 6.0 lmin1 with or without HMEs in a circle anaesthesia system. Relative humidity, absolute humidity, temperature of inspired gases and body temperatures were measured during 120 min of anaesthesia.<br/><br>
Results: The inspiratory absolute humidity levels with HMEs were 32.73.1, 32.11.1 and 29.21.9mg H2O l1 and 26.62.3, 22.63.0 and 13.02.6mgH2O l1 without HMEs after 120 min of anaesthesia with 1.0, 3.0, or 6.0 l min1 fresh gas flows (P&lt;0.05, between with and without HME). The relative humidity levels with HMEs were 93.83.3, 92.72.2<br/><br>
and 90.73.5%, and without the HMEs 95.24.5, 86.88.0 and 52.89.8% (P&lt;0.05, between with and without HMEs in the 3.0 and 6.0 lmin1 groups). The inspiratory gas temperatures with HMEs were 32.52.0, 32.40.5 and 31.01.9C, and 28.41.5,27.10.8 and 26.10.6C without HMEs after 120 min of anaesthesia (P&lt;0.05, between with and without HME). The tympanic membrane temperatures at 120 min of anaesthesia were<br/><br>
35.80.6, 35.50.6 and 35.40.8C in the groups with HMEs, and 35.80.6, 35.30.7 and 35.30.9C in the groups without the HMEs (NS).<br/><br>
Conclusions: The HMEs improved the inspiratory absolute humidity, relative humidity and temperature of the anaesthetic gases during different fresh gas flows. However, the HMEs were not able to prevent a body temperature drop during low-flow anaesthesia.},
  author       = {Johansson, Anders and Lundberg, Dag and Luttropp, Hans-Henrik},
  language     = {eng},
  number       = {5},
  pages        = {564--587},
  series       = {Acta Anaesthesiol Scand},
  title        = {The effect of heat and moisture exchanger on humidity and body temperature in a low-flow system},
  volume       = {47},
  year         = {2003},
}