A novel method of evaluation of three heat-moisture exchangers in six different ventilator settings

Ünal, Nurten; Kanhai, J. K K; Buijk, S.E.; Pompe, Jan C.; Holland, Wim; Gültuna, Ismail; İnce, Can; Saygin, B.; Bruining, H. A.

doi:10.1007/s001340050535

Cited by 39 publications

(24 citation statements)

References 35 publications

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“…In an experimental set-up this HME had been shown to have a satisfactory humidity output at lowflow rates (10). The relative humidity values that we recorded in our clinical setting using the HME indicate sufficient water vapour content for a satisfactory saturation at all present inspiratory temperatures.…”

Section: Discussionmentioning

confidence: 54%

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

Johansson

Lundberg

Luttropp

2003

Acta Anaesthesiol Scand

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The effect of heat and moisture exchanger on humidity and body temperature in a lowflow anaesthesia system. Lundberg, D., & Luttropp, H-H. (2003). The effect of heat and moisture exchanger on humidity and body temperature in a low-flow anaesthesia system. Acta Anaesthesiologica Scandinavica, 47(5), 564-568. DOI: 10.1034564-568. DOI: 10. /j.1399564-568. DOI: 10. -6576.2003 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal 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 l min À1 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 32.7 AE 3.1, 32.1 AE 1.1 and 29.2 AE 1.9 mg H 2 O l À1 and 26.6 AE 2.3, 22.6 AE 3.0 and 13.0 AE 2.6 mg H 2 O l À1 without HMEs after 120 min of anaesthesia with 1.0, 3.0, or 6.0 l min À1 fresh gas flows (P < 0.05, between with and without HME). The relative humidity levels with HMEs were 93.8 AE 3.3, 92.7 AE 2.2 and 90.7 AE 3.5%, and without the HMEs 95.2 AE 4.5, 86.8 AE 8.0 and 52.8 AE 9.8% (P < 0.05, between with and without HMEs in the 3.0 and 6.0 l min À1 groups). The inspiratory gas temperatures with HMEs were 32.5 AE 2.0, 32.4 AE 0.5 and 31.0 AE 1.9 C, and 28.4 AE 1.5,

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Section: Discussionmentioning

confidence: 54%

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

Johansson

Lundberg

Luttropp

2003

Acta Anaesthesiol Scand

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“…If the HME worked perfectly, it would completely trap the vapor in the expired gas and reuse 100% of the vapor during the next inspiration. In reality, however, some of the vapor escaped from the HME into the expired gas, and the AH at the end of the expiratory limb was not zero (Table 3), even though the type of HME that we used is one of the better performers [13,14]. Although further study is needed to confirm effect of HME performance on the accuracy of V T monitoring, we speculate that the better the performance of the HME, the less vapor passes through the HME; therefore, the larger will be the degree of underestimation of displayed V T .…”

Section: Discussionmentioning

confidence: 91%

Effect of humidifying devices on the measurement of tidal volume by mechanical ventilators

et al. 2006

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“…Previous studies, reported contradictory results on the effects of V E on HME performance during mechanical ventilation. [13][14][15] In fact, Unal et al 14 found better performance at lower V E , while Pelosi et al 15 demonstrated better performance at higher V E , and Chiumello et al 13 found the best performance at 10 L/min, with a decrease in performance both at higher and lower V E . However, contrary to our study, those authors did not test HMEs designed for tracheostomized patients during spontaneous breathing.…”

Section: Effect Of O 2 Flow and V Ementioning

confidence: 99%

“…In addition, a loss of HME efficiency during mechanical ventilation has been reported at high minute ventilation (V E ). 13,14 Our hypothesis was that additional O 2 flow and different V E will affect the efficiency of HMEs designed for tracheostomized spontaneously breathing patients.…”

Section: Introductionmentioning

confidence: 99%

In Vitro Evaluation of Heat and Moisture Exchangers Designed for Spontaneously Breathing Tracheostomized Patients

Brusasco¹,

Corradi

Vargas

et al. 2013

Respir Care

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BACKGROUND: Heat and moisture exchangers (HMEs) are commonly used in chronically tracheostomized spontaneously breathing patients, to condition inhaled air, maintain lower airway function, and minimize the viscosity of secretions. Supplemental oxygen (O 2 ) can be added to most HMEs designed for spontaneously breathing tracheostomized patients. We tested the efficiency of 7 HMEs designed for spontaneously breathing tracheostomized patients, in a normothermic model, at different minute ventilations (V E ) and supplemental O 2 flows. METHODS: HME efficiency was evaluated using an in vitro lung model at 2 V E (5 and 15 L/min) and 4 supplemental O 2 flows (0, 3, 6, and 12 L/min). Wet and dry temperatures of the inspiratory flow were measured, and absolute humidity was calculated. In addition, HME efficiency at 0, 12, and 24 h use was evaluated, as well as resistance to flow at 0 and 24 h. RESULTS: The progressive increase in O 2 flow from 0 to 12 L/min was associated with a reduction in temperature and absolute humidity. Under the same conditions, this effect was greater at lower V E . The HME with the best performance provided an absolute humidity of 26 mg H 2 O/L and a temperature of 27.8°C. No significant changes in efficiency or resistance were detected during the 24 h evaluation. CONCLUSIONS: The efficiency of HMEs in terms of temperature and absolute humidity is significantly affected by O 2 supplementation and V E .

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A novel method of evaluation of three heat-moisture exchangers in six different ventilator settings

Cited by 39 publications

References 35 publications

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

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

Effect of humidifying devices on the measurement of tidal volume by mechanical ventilators

In Vitro Evaluation of Heat and Moisture Exchangers Designed for Spontaneously Breathing Tracheostomized Patients

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