To improve the heat and humidification that can be achieved with a heat-and-moisture exchanger (HME), a hybrid active (ie, adds heat and water) HME, the Hygrovent Gold, was developed. We evaluated in vitro the performance of the Hygrovent Gold.
METHODS:
We tested the Hygrovent Gold (with and without its supplemental heat and moisture options activated), the Hygrobac, and the Hygrovent S. We measured the absolute humidity, using a test lung ventilated at minute volumes of 5, 10, and 15 L/min, in normothermic (expired temperature 34°C) and hypothermic (expired temperature 28°C) conditions. We also measured the HMEs' flow resistance and weight after 24 h and 48 h.
RESULTS:
In its active mode the Hygrovent Gold provided the highest absolute humidity, independent of minute volume, in both normothermia and hypothermia. The respective normothermia and hypothermia absolute humidity values at 10 L/min were 36.3 ± 1.3 mg/L and 27.1 ± 1.0 mg/L with the active Hygrovent Gold, 33.9 ± 0.5 mg/L and 24.2 ± 0.8 mg/L with the passive Hygrovent Gold, 33.8 ± 0.56 mg/L and 24.4 ± 0.4 mg/L with the Hygrobac, and 33.9 ± 0.8 mg/L and 24.6 ± 0.6 mg/L with the Hygrovent S. The efficiency of the tested HMEs did not change over time. At 24 h and 48 h the increase in weight and flow resistance was highest in the active Hygrovent Gold.
CONCLUSIONS:
The passive Hygrovent Gold provided adequate heat and moisture in normothermia, but the active Hygrovent Gold provided the highest humidity, in both normothermia and hypothermia.
ShellyMP, LloydGM, ParkGR. A review of the mechanisms and methods of humidification of inspired gases. Intensive Care Med, 1988; 14(1):1–9.
2.
BransonRD. Humidification for patients with artificial airways. Respir Care, 1999; 44(6):630–642.
3.
RogersDF. Physiology of airway mucus secretion and pathophysiology of hypersecretion. Respir Care, 2007; 52(9):1134–1146.
4.
ShellyMP. The humidification and filtration functions of the airways. Respir Care Clin N Am, 2006; 12(2):139–148.
5.
SottiauxTM. Consequences of under- and over-humidification. Respir Care Clin N Am, 2006; 12(2):233–252.
6.
CookD, RicardJD, ReeveB, RandallJ, WiggM, BrochardL, et al. Ventilator circuit and secretion management strategies: a Franco-Canadian survey. Crit Care Med, 2000; 28(10):3547–3554.
7.
American Association for Respiratory Care. AARC Clinical Practice Guideline. Humidification during mechanical ventilation. Respir Care, 1992; 37(8):887–890.
8.
KirtonOC, DeHavenB, MorganJ, MorejonO, CivettaJ. A prospective, randomized comparison of an in-line heat moisture exchange filter and heated wire humidifiers: rates of ventilator-associated early-onset (community-acquired) or late-onset (hospital-acquired) pneumonia and incidence of endotracheal tube occlusion. Chest, 1997; 112(4):1055–1059.
9.
LarssonA, GustafssonA, SvanborgL. A new device for 100 per cent humidification of inspired air. Crit Care, 2000; 4(1):54–60.
10.
BransonRD, DavisK, BrownR, RashkinM. Comparison of three humidification techniques during mechanical ventilation: patient selection, cost, and infection considerations. Respir Care, 1996; 41(9):809–816.
11.
DreyfussD, DjedainiK, GrosI, MierL, Le BourdellesG, CohenY, et al. Mechanical ventilation with heated humidifiers or heat and moisture exchangers: effects on patient colonization and incidence of nosocomial pneumonia. Am J Respir Crit Care Med, 1995; 151(4):986–992.
12.
RicardJD, BoyerA, DreyfussD. The effect of humidification on the incidence of ventilator-associated pneumonia. Respir Care Clin N Am, 2006; 12(2):263–273.
13.
KolaA, EckmannsT, GastmeierP. Efficacy of heat and moisture exchangers in preventing ventilator-associated pneumonia: meta-analysis of randomized controlled trials. Intensive Care Med, 2005; 31(1):5–11.
14.
UnalN, KanhaiJK, BuijkSL, PompeJC, HollandWP, GultunaI, et al. A novel method of evaluation of three heat-moisture exchangers in six different ventilator settings. Intensive Care Med, 1998; 24(2):138–146.
15.
RoustanJP, KienlenJ, AubasP, AubasS, du CailarJ. Comparison of hydrophobic heat and moisture exchangers with heated humidifier during prolonged mechanical ventilation. Intensive Care Med, 1992; 18(2):97–100.
16.
RathgeberJ. Devices used to humidify respired gases. Respir Care Clin N Am, 2006; 12(2):165–182.
17.
GiraultC, BretonL, RichardJC, TamionF, VandeletP, AboabJ, et al. Mechanical effects of airway humidification devices in difficult to wean patients. Crit Care Med, 2003; 31(5):1306–1311.
18.
PelosiP, SolcaM, RavagnanI, TubioloD, FerrarioL, GattinoniL. Effects of heat and moisture exchangers on minute ventilation, ventilatory drive, and work of breathing during pressure-support ventilation in acute respiratory failure. Crit Care Med, 1996; 24(7):1184–1188.
19.
NakagawaNK, MacchioneM, PetrolinoHM, GuimaraesET, KingM, SaldivaPH, et al. Effects of a heat and moisture exchanger and a heated humidifier on respiratory mucus in patients undergoing mechanical ventilation. Crit Care Med, 2000; 28(2):312–317.
20.
PelosiP, ChiumelloD, SevergniniP, De GrandisCE, LandiL, ChierichettiLM, et al. Performance of heated wire humidifiers: an in vitro study. J Crit Care, 2007; 22(3):258–264.
21.
ThieryG, BoyerA, PigneE, SalahA, De LassenceA, DreyfussD, et al. Heat and moisture exchangers in mechanically ventilated intensive care unit patients: a plea for an independent assessment of their performance. Crit Care Med, 2003; 31(3):699–704.
22.
MartinC, ThomachotL, QuinioB, ViviandX, AlbaneseJ. Comparing two heat and moisture exchangers with one vaporizing humidifier in patients with minute ventilation greater than 10 L/min. Chest, 1995; 107(5):1411–1415.
23.
RicardJD, Le MiereE, MarkowiczP, LasryS, SaumonG, DjedainiK, et al. Efficiency and safety of mechanical ventilation with a heat and moisture exchanger changed only once a week. Am J Respir Crit Care Med, 2000; 161(1):104–109.
24.
DjedainiK, BilliardM, MierL, Le BourdellesG, BrunP, MarkowiczP, et al. Changing heat and moisture exchangers every 48 hours rather than 24 hours does not affect their efficacy and the incidence of nosocomial pneumonia. Am J Respir Crit Care Med, 1995; 152(5 Pt 1):1562–1569.
25.
ChiumelloD, PelosiP, ParkG, CandianiA, BottinoN, StorelliE, et al. In vitro and in vivo evaluation of a new active heat moisture exchanger. Crit Care, 2004; 8(5):R281–R288.
26.
ThomachotL, ViviandX, BoyadjievI, VialetR, MartinC. The combination of a heat and moisture exchanger and a Booster: a clinical and bacteriological evaluation over 96 h. Intensive Care Med, 2002; 28(2):147–153.
27.
BransonRD, CampbellR, JohannigmanJA, OttawayM, DavisK, LuchetteF, et al. Comparison of conventional heated humidification with a new active hygroscopic heat and moisture exchanger in mechanically ventilated patients. Respir Care, 1999; 44(8):912–917.
28.
KapadiaF, ShellyMP, AnthonyJM, ParkGR. An active heat and moisture exchanger. Br J Anaesth, 1992; 69(6):640–642.
29.
LelloucheF, QaderS, TailleS, LyazidiA, BrochardL. Under-humidification and over-humidification during moderate induced hypothermia with usual devices. Intensive Care Med, 2006; 32(7):1014–1021.
30.
ChiarandaM, VeronaL, PinamontiO, DominioniL, MinojaG, ContiG. Use of heat and moisture exchanging (HME) filters in mechanically ventilated ICU patients: influence on airway flow-resistance. Intensive Care Med, 1993; 19(8):462–466.
31.
PratG, RenaultA, TonnelierJM, GoetghebeurD, OgerE, BolesJM, et al. Influence of the humidification device during acute respiratory distress syndrome. Intensive Care Med, 2003; 29(12):2211–2215.
32.
RicardJD, CookD, GriffithL, BrochardL, DreyfussD. Physicians' attitude to use heat and moisture exchangers or heated humidifiers: a Franco-Canadian survey. Intensive Care Med, 2002; 28(6):719–725.
