With so mant HMEs on the market today. Have any of you had any problems with your HMEs.What type of HME are you using?PALLARCGibeckEnternetClimavent
February 22, 2007, 06:52 AM
<Brian>
An HME is an Hme is an HME. The fact is that HME's should be used for short term ventilation and for long term Active Humidification (Fisher&Paykel) should be used.
February 22, 2007, 06:27 PM
JeffWhitnack
Well there are some studies by Branson and others showing some variation in HME's (more deadspace means better humidification, etc.).
A while back I did an informal survey on RC World. A lot of places use heated/active humidity from day one. A lot use some forumula whereby HME usage is followed by heated/active humidification. But about 1/3 used HME from day one on.....One of them was a local long term care facility (trached patients).
In normal people the air at the carina is 32 degrees and 100% humidified. No one has ever proven that in intubated or critically ill patients there is a need to increase that to 37 degrees and 100%. And a study by Brochard recently showed that the attempt to do this probably results in the worst---hot and dry air. At least if the air is cool and dry the airways can heat and humidify in tandem. If the air is hot and dry there is a (quoting Ross Perot) a great sucking sound as the airways are dessicated. We have probably all seen where people decrease the RH setting in order to cut down on water deposition.
February 28, 2007, 11:34 AM
Bill C
I do know that there are some studies being done in the Southwest and I have witnessed myself that HMEs can be sufficient. I have not had in the last 5 years any problems with using HMEs only for my patients. It has even helped to decrease my VAP rates.
March 02, 2007, 09:20 AM
JeffD
In my institution we use a both HMEs and heated humidity. HME's are used on short term patients (e.g post-op) and heated humidity for greater than 48 hours.
We recently started using the Bact-HME from Pharma-systems (www.pharmasystems-ps.com/index.html), these HME/Filters have a N100 rating and a resistance of 1.1 cmH2O/l/s.
How often are people changing HMEs? Every 24 hours, 48 hours, when visibly soiled? And is there concerns about breaking/opening the patients circuit each time you change an HME?
My concern with HMEs is adding that amount of deadspace to the ventilator circuit with our more critically ill patients.
Heat and moisture exchangers and heated humidifiers in acute lung injury/acute respiratory distress syndrome patients. Effects on respiratory mechanics and gas exchange. Indalecio Morán, Judith Bellapart, Alessandra Vari and Jordi Mancebo. Intensive Care Med. 2006 Apr;32(4):524-31.
OBJECTIVE: To compare, in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) patients, the short-term effects of heat and moisture exchangers (HME) and heated humidifiers (HH) on gas exchange, and also on respiratory system mechanics when isocapnic conditions are met. DESIGN: Prospective open clinical study. SETTING: Intensive Care Service. PATIENTS: Seventeen invasively ventilated ALI/ARDS patients. INTERVENTION: The study was performed in three phases: (1) determinations were made during basal ventilatory settings with HME; (2) basal ventilatory settings were maintained and HME was replaced by an HH; (3) using the same HH, tidal volume (Vt) was decreased until basal PaCO(2) levels were reached. FiO(2), respiratory rate and PEEP were kept unchanged. MEASUREMENTS AND RESULTS: Respiratory mechanics, Vd(phys), gas exchange and hemodynamic parameters were obtained at each phase. By using HH instead of HME and without changing Vt, PaCO(2) decreased from 46 +/- 9 to 40 +/- 8 mmHg (p < 0.001) and Vd(phys) decreased from 352 +/- 63 to 310 +/- 74 ml (p < 0.001). Comparing the first phase with the third, Vt decreased from 521 +/- 106 to 440 +/- 118 ml (p < 0.001) without significant changes in PaCO(2), Vd/Vt decreased from 0.69 +/- 0.11 to 0.62 +/- 0.12 (p < 0.001), plateau airway pressure decreased from 25 +/- 6 to 21 +/- 6 cmH(2)O (p < 0.001) and respiratory system compliance improved from 35 +/- 12 to 42 +/- 15 ml/cmH(2)O (p < 0.001). PaO(2) remained unchanged in the three phases. CONCLUSIONS: Reducing dead space with the use of HH decreases PaCO(2) and more importantly, if isocapnic conditions are maintained by reducing Vt, this strategy improves respiratory system compliance and reduces plateau airway pressure.
ALI/ARDS diagnosis was made based on America-European Consensus Conference definition and the HME used was an Edith Flex with a dead-space of 90ml.
This study shows that by simply using HH instead of an HME in ALI/ARDS patients reduces dead-space lowering PaCO2, this allows the patient to be ventilated with lower tidal volumes and lower plateau pressures. In this study the lower tidal volumes significantly improved respiratory compliance in the patients. Although the differences in PaCO2 were only moderate, increasing the respiratory rate to compensate for the dead-space from the HME may induce gas trapping and auto-PEEP or simply may enhance ventilator-induced lung injury.
I also find it very interesting that it has been commented that HMEs have decreased VAP rates in some centers. Is this observational comment? Because this has been studied thoroughly and it has not been clearly shown that HMEs reduce VAP. Other interventions have a large impact on VAP (e.g. head of bed >30 degrees, use of OGs instead of NGs, stress ulcer prohylaxis etc.). I just wonder is the decrease in VAP due to HME use or other changes in patient care. But you may have well seen a change in VAP rates due to HME use in your institution, it just seems like it may be a difficult thing to measure, kinda of like comparing VAP rates with inline and open suction systems.
I think the HH vs. HME is a debate that will go on for a long time but it is good to always discuss these things and see what others are doing.
here in our hospital, we are currently using HME brought about by the infection control dept's instructions to decrease incidence of VAP(due to wet humidification). We thought its rt friendly (as its easy to maintain vs wet - considering also were not following rt/pt ratio).. We only use wet humidification on pediatric patients due to deadspace caused by HME...This message has been edited. Last edited by: ric crt,
April 12, 2007, 11:04 AM
rt3
How often do you change your HME's?
quote:
Originally posted by JeffD: In my institution we use a both HMEs and heated humidity. HME's are used on short term patients (e.g post-op) and heated humidity for greater than 48 hours.
We recently started using the Bact-HME from Pharma-systems (www.pharmasystems-ps.com/index.html), these HME/Filters have a N100 rating and a resistance of 1.1 cmH2O/l/s.
How often are people changing HMEs? Every 24 hours, 48 hours, when visibly soiled? And is there concerns about breaking/opening the patients circuit each time you change an HME?
My concern with HMEs is adding that amount of deadspace to the ventilator circuit with our more critically ill patients.
Heat and moisture exchangers and heated humidifiers in acute lung injury/acute respiratory distress syndrome patients. Effects on respiratory mechanics and gas exchange. Indalecio Morán, Judith Bellapart, Alessandra Vari and Jordi Mancebo. Intensive Care Med. 2006 Apr;32(4):524-31.
OBJECTIVE: To compare, in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) patients, the short-term effects of heat and moisture exchangers (HME) and heated humidifiers (HH) on gas exchange, and also on respiratory system mechanics when isocapnic conditions are met. DESIGN: Prospective open clinical study. SETTING: Intensive Care Service. PATIENTS: Seventeen invasively ventilated ALI/ARDS patients. INTERVENTION: The study was performed in three phases: (1) determinations were made during basal ventilatory settings with HME; (2) basal ventilatory settings were maintained and HME was replaced by an HH; (3) using the same HH, tidal volume (Vt) was decreased until basal PaCO(2) levels were reached. FiO(2), respiratory rate and PEEP were kept unchanged. MEASUREMENTS AND RESULTS: Respiratory mechanics, Vd(phys), gas exchange and hemodynamic parameters were obtained at each phase. By using HH instead of HME and without changing Vt, PaCO(2) decreased from 46 +/- 9 to 40 +/- 8 mmHg (p < 0.001) and Vd(phys) decreased from 352 +/- 63 to 310 +/- 74 ml (p < 0.001). Comparing the first phase with the third, Vt decreased from 521 +/- 106 to 440 +/- 118 ml (p < 0.001) without significant changes in PaCO(2), Vd/Vt decreased from 0.69 +/- 0.11 to 0.62 +/- 0.12 (p < 0.001), plateau airway pressure decreased from 25 +/- 6 to 21 +/- 6 cmH(2)O (p < 0.001) and respiratory system compliance improved from 35 +/- 12 to 42 +/- 15 ml/cmH(2)O (p < 0.001). PaO(2) remained unchanged in the three phases. CONCLUSIONS: Reducing dead space with the use of HH decreases PaCO(2) and more importantly, if isocapnic conditions are maintained by reducing Vt, this strategy improves respiratory system compliance and reduces plateau airway pressure.
ALI/ARDS diagnosis was made based on America-European Consensus Conference definition and the HME used was an Edith Flex with a dead-space of 90ml.
This study shows that by simply using HH instead of an HME in ALI/ARDS patients reduces dead-space lowering PaCO2, this allows the patient to be ventilated with lower tidal volumes and lower plateau pressures. In this study the lower tidal volumes significantly improved respiratory compliance in the patients. Although the differences in PaCO2 were only moderate, increasing the respiratory rate to compensate for the dead-space from the HME may induce gas trapping and auto-PEEP or simply may enhance ventilator-induced lung injury.
I also find it very interesting that it has been commented that HMEs have decreased VAP rates in some centers. Is this observational comment? Because this has been studied thoroughly and it has not been clearly shown that HMEs reduce VAP. Other interventions have a large impact on VAP (e.g. head of bed >30 degrees, use of OGs instead of NGs, stress ulcer prohylaxis etc.). I just wonder is the decrease in VAP due to HME use or other changes in patient care. But you may have well seen a change in VAP rates due to HME use in your institution, it just seems like it may be a difficult thing to measure, kinda of like comparing VAP rates with inline and open suction systems.
I think the HH vs. HME is a debate that will go on for a long time but it is good to always discuss these things and see what others are doing.