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In the 1940s in Chicago, Illinois, a group of oxygentank technicians began meeting with doctors concerned with lung disease. This group named itself the Inhalational Therapy Association ("ITA") in 1946. They gradually put together a series of classes for people administering medical gases to patients. 2
In December, 1950, 31 members of the Association were issued certificates for attending 16 lectures. This was the first certification of "inhalation therapists. It was an on-the-job training system for so-called "oxygen jockies". They had little formal education, but did have a desire to do their jobs better and help patients in the process. 3
June 2005 Respiratory Care Journal HMEs should be used in all patients in whom there is no contraindication. Richard D. Branson MSc RRT FAARC 4
After this presentation, you will have a general understanding regarding: The basic science of how PH work AARC Clinical Guidelines 30/30 Indications & Contraindications How PH performances are measured Documentation of PH effectiveness The benefits of the ThermoFlo Humidification System
Humidity is the occurrence of water vapor in a gas. The maximum humidity increases with increasing temperature. Absolute Humidity is defined as the actual humidity measured as mg of water per liter of gas. Relative Humidity is the relationship between absolute humidity and the maximum humidity which gas can contain, expressed as a percentage, at a given temperature. 6
The upper respiratory tract of a person during normal breathing warms, humidifies and filters inspired air from the nose and mouth. The upper respiratory tract is lined by a warm, viscous mucous membrane. As air passes over the membrane, heat and humidity is added to the inspired air before it reaches the lower airways and lungs. 7
This membrane is also lined with very small microscopic cilia which act as an airway protection mechanism because the cilia s constant movement is designed to expel any inhaled contaminants lodged in the airway. When a person exhales, the upper airway also traps most of the heat and moisture in the exhaled breath so that it can be reused during the next inhaled breath. 8
When a person is orally or nasally intubated, the artificial airway bypasses these important mechanisms of heat and moisture exchange that are normally performed by the upper respiratory tract. The loss of this functionality increases the risk of patient hypothermia, thickening of airway secretions and possible destruction of the airway surface. 9
To help prevent this condition from happening, practical guidelines recommend that clinicians place an artificial heat and moisture exchanger or PH passive humidifier inline in the patients breathing circuit on all intubated patients. The PH functions as an artificial airway because it captures and re-uses the patient s heat and moisture just like the upper respiratory tract. 10
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The first heat/moisture exchanger, which was made of corrugated aluminum, was presented by a group of Swedish professors in the early 1960 s. Due to its weight, the device never became widely used. The market breakthrough for the artificial nose did not occur until the beginning of the 1970 s. 13
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The aluminum was replaced with a special paper in a corrugated structure with a large capacity for absorbing and giving off moisture. Over the years the noses have been gradually developed and the design has been refined. 15
There are 4 types of passive humidifiers. 16
H M E heat and moisture exchanger least amount of moisture returned H M E F filtered heat and moisture exchanger second lowest amount of moisture returned H C H hygroscopic condensing humidifier second highest amount of moisture returned H C H F filtered hygroscopic condensing humidifier highest amount of moisture returned 17
Heat and Moisture Exchanger Natural physical properties only Hygroscopic Condenser Humidifier Enhancement of the natural physical properties Calcium Chloride Condensation 18
The chosen device should provide a minimum of 30 mg H2O/L of delivered gas at 30 C. 19
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The patient has humidity and heat within their lungs. When the air or gas is forced out of the lungs, the PH collects or conserves that heat and humidity. When this breath is exhaled, the gas passes through the PH and the heat and humidity or moisture is transferred to the PH. When the second breath from the ventilator passes through the PH, it picks up heat and humidity from the PH and delivers it back to the patient s lungs and so on. 21
This continues and the patient s moisture needs are meet. Many products fail to meet the patient s needs resulting in adverse events such as: high pressure alarms, spontaneous pneumothorax, thick secretions, endotube occlusions, plugged airways and more. 22
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Charging is a function used by many manufactures to explain why their devices drain moisture from the patient s breath. Coring is the result from the charging process and the drying of the patient the yellow spot on a cigarette filter is similar. The longer you use this type PH, the more problems you will encounter. 24
30/30? 25
INDICATIONS: Humidification of inspired gas during mechanical ventilation is mandatory when an endotracheal or tracheostomy tube is present. 26
CONTRAINDICATIONS: Patients with preexisting pulmonary disease characterized by thick, copious, or bloody secretions should not use PH. Use of an PH is contraindicated for patients with an expired tidal volume less than 70% of the delivered tidal volume. 27
The chosen device should provide a minimum of 30 mg H2O/L of delivered gas at 30 C. 30mg + 14mg = 44mg 28
30/30 29
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Filter Design Cost Dead space Resistance Moisture output 31
HME lowest HMEF HCH HCHF highest 32
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Most product literature today is misleading. Resistance wet? dry? first hour of use? last hour of use? And so on Does the moisture return remain the same over 24 hours? 35
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Third party, third party, third party - but who funds the study? Does the investigator have a financial interest? In house studies are like calling your own balls and strikes. 39
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Any patient on a ventilator shall have 30mg of moisture delivered at 30 0 C. 42
Spun Polypropylene ( plastic coated with CaCl - ) 43
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