Abstract
Objective
To investigate the effects of a heat and moisture exchanger (HME) on the temperature
and humidity of inhaled gas in isoflurane-anesthetized dogs.
Study design
Prospective, interventional study.
Animals
A total of four experimental dogs and four client-owned dogs weighing 13.9 ± 7.4 kg
(mean ± standard deviation).
Methods
The four experimental dogs were anesthetized on two occasions with and without an
intact HME at least 1 week apart. The four client-owned dogs were anesthetized once
only for a surgical procedure and assigned to the HME group or no-HME group in alternate
order, resulting in six dogs for each group. All dogs were premedicated, anesthetized
with propofol and intubated. The HME was connected to the endotracheal tube. Anesthesia
was maintained with isoflurane. A digital thermo-hygrometer was placed between the
endotracheal tube and HME. The temperature and relative humidity of the inhaled gas
were measured every 5 minutes for 60 minutes and the absolute humidity was calculated
at each time point.
Results
The temperature and absolute humidity of the inhaled gas was significantly higher
at 5–60 minutes after intubation in the HME group than in the no-HME group. Absolute
humidity was maintained above 29 mg H2O L−1 in the HME group. No significant time-dependent effects on temperature, relative
humidity or absolute humidity of the inhaled gas were observed.
Conclusions and clinical relevance
The temperature and absolute humidity of the inhaled gas were higher when an HME was
used during isoflurane anesthesia in dogs. The use of an HME may reduce the risk of
dehydration and dysfunction of the airway mucosal epithelium.
Keywords
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Veterinary Anaesthesia and AnalgesiaAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- The effect of a heat and moisture exchanger on humidity in a low-flow anaesthesia system.Anaesthesia. 1997; 52: 144-149
- Effects of dry air and subsequent humidification on tracheal mucous velocity in dogs.J Appl Physiol. 1975; 39: 242-246
- Effect of a heat and moisture exchanger on heat loss in isoflurane-anesthetized dogs undergoing single-limb orthopedic procedures.J Am Vet Med Assoc. 2011; 239: 1561-1565
- The effect of heat and moisture exchanger on humidity and body temperature in a low-flow anaesthesia system.Acta Anaesthesiol Scand. 2003; 47: 564-568
- Do heat and moisture exchangers in the anaesthesia breathing circuit preserve body temperature in dogs undergoing anaesthesia for magnetic resonance imaging?.Vet Anaesth Analg. 2017; 44: 452-460
- Humidity of anaesthetic gases with respect to low flow anaesthesia.Anaesth Intensive Care. 1994; 22: 396-408
- The benefit of using a heat and moisture exchanger during short operations in young children.Paediatr Anaesth. 1997; 7: 295-300
- The effect of heat and moisture exchanger and gas flow on humidity and temperature in a circle anaesthetic system.Singapore Med J. 2002; 43: 563-565
- Humidification during invasive and noninvasive mechanical ventilation: 2012.Respir Care. 2012; 57: 782-788
- Microvascular anatomy of the nose.Allergy. 1997; 52: 7-11
Article info
Publication history
Published online: February 26, 2020
Accepted:
February 14,
2020
Received:
August 20,
2019
Identification
Copyright
© 2020 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.
