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Viasis Vela/ LTV 950

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https://ventworld.infopop.cc/eve/forums/a/tpc/f/2616042361/m/7891061982

December 05, 2007, 11:25 AM
CdnRT
Viasis Vela/ LTV 950
As well, there's an article detailing the temperature at the outlet port of the LTV being excessive thus affecting the performance of the Paykel humidifers. If interested, let me know and I'll dig it up. We have 4 LTV 1000 and 1 1200 which are used strictly for transfer and have held up quite well.
December 05, 2007, 09:50 PM
yomonk1
Yes, Thank you. I would like to see this article. We use LTV with F&P frequently and are very interested. Thanks!!
December 06, 2007, 06:10 AM
CdnRT
Log on to pub med and download the article; if you don't have access, let me know (with your email) and I'll email a PDF to you. I attached the abstract at the bottom but the complete article is great reading.

Influence of ambient and ventilator output temperatures on performance of heated-wire humidifiers.Am J Respir Crit Care Med. 2004 Nov 15;170(10):1073-9. Epub 2004 Jul 21. PMID: 15271695 [PubMed - indexed for MEDLINE]

Lellouche F, Taillé S, Maggiore SM, Qader S, L'her E, Deye N, Brochard L.
Service de Réanimation Médicale, Hôpital Henri Mondor, INSERM U492, Université Paris XII Créteil, France.

Although heated humidifiers are considered the most efficient humidification devices for mechanical ventilation, endotracheal tube occlusion caused by dry secretions has been reported with heated-wire humidifiers. We tested the hypothesis that inlet chamber temperature, influenced by ambient air and ventilator output temperatures, may affect humidifier performance, as assessed by hygrometry. Hygrometry was measured with three different humidifiers under several conditions, varying ambient air temperatures (high, 28-30 degrees C; and normal, 22-24 degrees C), ventilators with different gas temperatures, and two VE levels. Clinical measurements were performed to confirm bench measurements. Humidifier performance was strongly correlated with inlet chamber temperature in both the bench (p < 0.0001, r2 = 0.93) and the clinical study. With unfavorable conditions, absolute humidity of inspired gas was much lower than recommended (approximately 20 mg H2O/L). Performance was improved by specific settings or new compensatory algorithms. Hygrometry could be evaluated from condensation on the wall chamber only when ambient air temperature was normal but not with high air temperature. An increase in inlet chamber temperature induced by high ambient temperature markedly reduces the performance of heated-wire humidifiers, leading to a risk of endotracheal tube occlusion. Such systems should be avoided in these conditions unless automatic compensation algorithms are used.

PMID: 15271695 [PubMed - indexed for MEDLINE]
December 09, 2007, 09:48 PM
yomonk1
Is there information specific to the F&P heater and the LTV?
December 09, 2007, 11:30 PM
JeffWhitnack
They used F&P heaters (and another one or two I believe) in the study mentioned above.