November 2nd , 2022 ALL ABOUT HUMIDIFICATION NAPARAT AMORNPUTTISATHAPORN M.D. & YUPAWADEE KOOMWONG ,RN RESPIRATORY AND CRITICAL CARE MEDICINE UNIT, MEDICINE DEPARTMENT, FACULTY OF MEDICINE, RAMATHIBODI HOSPITAL, MAHIDOL UNIVERSITY
OBJECTIVE • DESCRIBE HOW AIRWAY HEAT AND MOISTURE EXCHANGE NORMALLY OCCURS • STATE THE EFFECT DRY GASES HAVE ON THE RESPIRATORY TRACT • STATE WHEN TO HUMIDIFY AND WARM INSPIRED GAS • DESCRIBE HOW VARIOUS TYPES OF HUMIDIFIERS WORK • IDENTIFY THE INDICATIONS, CONTRAINDICATIONS, AND HAZARDS THAT PERTAIN TO HUMIDIFICATION DURING MECHANICAL VENTILATOR • DESCRIBE HOW TO MONITOR PATIENTS RECEIVING HUMIDITY THERAPY • DESCRIBE HOW TO IDENTIFY AND RESOLVE COMMON PROBLEMS WITH HUMIDIFICATION SYSTEMS
HUMIDIFICATION HUMIDIFICATION คอื การทาใหน้ า้ ระเหยเป็ นไอ(VAPORIZATION) แล้วลอยปะปนไปกบั อากาศหรือออกซเิ จน
WHAT IS HUMIDITY Absolute humidity (AH) หมายถงึ ปริมาณไอนา้ ทมี่ อี ยู่จริงในก๊าซขณะนั้น มี หน่วยเป็ นมลิ ลิกรัมหรือกรัมของนา้ ตอ่ ปริมาตรก๊าซ 1 ลิตร Relative humidity(RH) หมายถงึ สัดส่วนของปริมาณไอนา้ ทมี่ อี ย่จู ริงในก๊าซ ขณะหน่ึงๆตอ่ ปริมาณไอนา้ สูงสุดทส่ี ามารถมีอยไู่ ดใ้ นก๊าซขณะนั้น มหี น่วยเป็ น เปอรเ์ ซนต์ Vapour pressure หมายถงึ การวัดความชนื้ ในลักษณะของความดนั ไอนา้ ในอากาศ มีหน่วยเป็ นมลิ ลเิ มตรปรอทหรือ ทอรร(์ mmHg,Torr)
WATER VAPOUR IN RELATION TO TEMPERATURE
NORMAL AIRWAY HUMIDIFICATION • THE NOSE WARMS, HUMIDIFIES, AND FILTERS INSPIRED AIR • THE PHARYNX, TRACHEA, AND BRONCHIAL TREE ALSO WARM, HUMIDIFY, AND FILTER INSPIRED AIR • BY THE TIME THE INSPIRED AIR REACHES THE OROPHARYNX, IT HAS BEEN WARMED TO APPROXIMATELY 34OC AND IS 80%-90% SATURATED WITH H2O • BY THE TIME THE INSPIRED AIR REACHES THE CARINA, IT HAS BEEN WARMED TO BODY TEMPERATURE (37OC) AND IS 100% SATURATED
CONDITIONING OF INSPIRATORY GAS IN UPPER AND LOWER RESPIRATORY SYSTEMS 12 3 4 5 6
NORMAL AIRWAY HUMIDIFICATION • WHEN THE INSPIRED AIR IS FULLY SATURATED (100%) AT 37OC, IT HOLDS 44 MG H2O PER LITER OF GAS AND EXERTS A WATER VAPOR PRESSURE OF 47 MMHG • AS INSPIRED GAS MOVES INTO THE LUNGS, IT ACHIEVES BTPS CONDITIONS (BODY TEMPERATURE, 37OC) • AS INSPIRED GAS ACHIEVES BTPS CONDITIONS AT ISOTHERMIC SATURATION BOUNDARY (ISB), THIS POINT IS NORMALLY APPROXIMATELY 5 CM BELOW THE CARINA • NUMEROUS FACTORS CAN SHIFT THE ISB DEEPER INTO THE LUNGS
RESPIRATORY GAS CONDITIONING Temp RH AH Temp RH AH
HUMIDITY DEFICIT From Fink J: Humidity and aerosol therapy. In Cairo J, Pilbeam S, editors: Mosby’s respiratory equipment, ed 8, St. Louis, 2010, Mosby.
HUMIDITY THERAPY • HUMIDITY IS THE QUANTITY OF MOISTURE IN AIR OR GAS THAT IS CAUSED BY THE ADDITION OF WATER IN A GASEOUS STATE, OR VAPOR. ALSO CALLED MOLECULAR WATER OR INVISIBLE MOISTURE. • CLINICAL USES OF HUMIDITY • TO PROVIDE 100% BODY HUMIDITY OF THE INSPIRED GAS FOR PATIENTS WITH ET TUBES OR TRACHEOSTOMY TUBES • TO HUMIDIFY DRY THERAPEUTIC GASES
INDICATIONS • PRIMARY • SECONDARY • OVERCOMING HUMIDITIY DEFICIT (UPPER • TO MANAGE HYPOTHERMIA AIRWAY BYPASS) • TO TREAT BRONCHOSPASM (DUE TO COLD • TO HUMIDIFY DRY MEDICAL GASSES AIR)
CLINICAL SIGNS AND SYMPTOMS OF INADEQUATE HUMIDIFICATION • DRY AND NON-PRODUCTIVE COUGH • ATELECTASIS • INCREASED AIRWAY RESISTANCE • INCREASED WORK OF BREATHING • INCREASED INCIDENCE OF INFECTION • THICK AND DEHYDRATED SECRETIONS • COMPLAINTS OF SUBSTERNAL PAIN AND AIRWAY DRYNESS
SYSTEMIC HYDRATION • INCREASE THE AMOUNT OF FLUID INTAKE ORALLY OR INTRAVENOUS • TO KEEP OUR BODY FROM DEHYDRATED • TO AVOID AIRWAY SECRETION BECOME MORE TENACIOUS
CONSEQUENCES OF UNDER-HUMIDIFICATION • SEVERE HEAT AND MOISTURE LOSS FROM THE RESPIRATORY MUCOSA LEADING TO DESTRUCTION OF CILIA AND DAMAGE TO MUCUS GLANDS • POOLING OF MUCOUS DUE TO SLOWING OF MUCOCILIARY SYSTEM LEADING TO INCREASED SPUTUM RETENTION AND ATELECTASIS • TRACHEITIS • INFECTION • BRONCHOCONSTRICTION LEADING TO REDUCED AIRFLOW AND DECREASED OXYGENATION AND SPO2 • AIRWAY OBSTRUCTION Russell 2005, Woodrow 2002, Jackson 1996, Buglass 1999
MUCOCILIARY CLEARANCE • THE MAIN BRONCHI DOWN TO THE ALVEOLI ARE LINED WITH A RESPIRATORY EPITHELIUM. ON IT, CILIUM IS EXISTENT, BEARING HAIR-SHAPED STRUCTURES ON ITS SURFACE (CILIA). • THE CILIA ARE SURROUNDED BY FLUID MUCOUS LAYER, THE PERICILIARY LIQUID. • THIS CILIARY LAYER IS COVERED BY VISCOUS MUCUS WHICH STRAPS FOREIGN MATTER AND MICROORGANISMS.
MUCOCILIARY CLEARANCE • THE COORDINATED MOVEMENT OF THE CILIA IN THE PERICILIARY LIQUID TRNASPORTS THE MUCUS TOGETHER WITH FOREIGN MATTER TOWARDS THE MOUTH, WHERE IT CAN BE SWALLOWED OR COUGHED UP. • THE EFFICIENCY OF THE IS CLEARANCE MECHANISUM DEPENDS ON THE NUMBER OF CILA, THEIR STRUCTURE AND MOTILITY, AND THE QUANTITY AND CONSITENCY OF THE MUCUS.
MUCOCILIARY CLEARANCE • OPTIMUM FUNCTIONALITY OF THE MUCOCILARY CLEARANCE REQUIRES A TEMPERATURE OF 37OC AND AN ABSOLUTE HUMIDITY OF 44 MG/DM3 CORRESPONSING TO A RELATIVE HUMIDITY OF 100%. • INSUFFUCIENT HEAT AND MOISTURE IN THE LOWER RESPIRATORY TRACT CAUSE THE CILIARY CELLS TO STOP STRANSPORTING. UNDER THESE CONDITIONS, BACTERIAL GERMINAL COLONIZATION IS FACILTATED.
ISOTHERMIC SATURATION BOUNDARY (ISB) • THE ISB SHIFTS DISTALLY : • WHEN A PERSON BREATHES THROUGH THE MOUTH RATHER THAN THE NOSE • WHEN THE PERSON BREATHES COLD, DRY AIR • WHEN THE UPPER AIRWAY IS BYPASSD (BREATHING THROUGH AN ARTIFICIAL TRACHEAL AIRWAY) • WHEN THE MINUTE VENTILATION IS HIGHER THAN NORMAL
ISOTHERMIC SATURATION BOUNDARY (ISB) • WHEN THIS SHIFT OF ISB OCCURS, ADDITIONAL SURFACES OF THE AIRWAY ARE RECRUITED TO MEET THE HEAT AND HUMIDITY REQUIREMENTS OF THE LUNG. • THIS RECRUITMENT OF AIRWAYS THAT DO NOT TYPICALLY PROVIDE THIS LEVEL OF HEAT AND HUMIDITY CAN HAVE A NEGATIVE IMPACT ON EPITHELIAL INTEGRITY. • THESE SHIFTS OF THE ISB CAN COMPROMISE THE BODY’S NORMAL HEAT AND MOISTURE EXCHANGE MECHANISMS, AND HUMIDITY THERAPY IS INDICATED
EFFECTS OF HUMIDITY VS EXPOSURE TIME ON AIRWAY DYSFUNCTION
THE RESULTS OF NON-INVASIVE AND INVASIVE RESPIRATION ARE: • INSUFFICIENT WARMING EFFECT • INSUFFICIENT HUMIDIFICATION EFFECT • CONSTRAINED CLEARANCE OF THE RESPIRATORY TRACT
PULMONARY PHYSIOLOGY OF HUMIDITY DEFICIT AFTER ENDOTRACHEAL INTUBATION UPPER AIRWAY LOSES ITS CAPACITY TO PROVIDE HEAT AND MOISTURE TO INHALED GAS ISB IS SHIFTED DOWN THE RESPIRATORY TRACT INCREASED BURDEN ON THE LOWER RESPIRATORY TRACT (NOT WELL PREPARED FOR THE HUMIDIFICATION PROCESS) DELIVERY OF PARTIALLY COLD & DRY MEDICAL GASES POTENTIAL DAMAGE TO THE RESPIRATORY EPITHELIUM INCREASED WORK OF BREATHING, ATELECTASIS, THICK & DEHYDRATED SECRETIONS, COUGH AND/OR BRONCHOSPASM
TYPES OF HUMIDIFIERS • HUMIDIFIERS ARE EITHER ACTIVE (ACTIVELY ADDING HEAT OR WATER OR BOTH TO THE DEVICE-PATIENT INTERFACE) OR PASSIVE (RECYCLING EXHALED HEAT AND HUMIDITY FROM THE PATIENT) • ACTIVE HUMIDIFIERS TYPICALLY INCLUDE: • BUBBLE HUMIDIFIERS • PASSOVER HUMIDIFIERS • NEBULIZERS OF BLAND AEROSOLS • VAPOURIZERS • PASSIVE HUMIDIFIERS REFER TO TYPICAL HEAT AND MOISTURE EXCHANGERS (HMES)
HUMIDITY OF COMPRESSED O2 • ALL COMPRESSED O2 AND LIQUID O2 : NO HUMIDITY! • LONG TIME USE OF DRY OXYGEN WILL OVERCOME THE HUMIDIFICATION CAPACITY Dry OF THE NASAL CAVITY / MUCOSA nose?? • DRY MUCOSA DISCOMFORT / IRRITATION • DRY SPUTUM DIFFICULT TO EXPECTORATE • IN MOST SITUATIONS, WE WILL NEED TO RAISE THE MOISTURE OF THE OXYGEN BEFORE GIVEN TO THE PATIENTS
HUMIDIFICATION / NEBULIZATION • 2 MAJOR WAYS TO INCREASE MOISTURE • HUMIDIFICATION • MAKE WATER VAPORIZED (GAS STATE) AND DISSOLVED IN THE AIR (INCREASE HUMIDITY) Humidity : measured by hygrometer • NEBULIZATION • MAKE WATER DISPERSED IN TO “AEROSOL” (TINY DROPLETS) • COLLOIDS OF WATER IN THE AIR Example of aerosol in Switzerland
HUMIDIFICATION • USED IN GENERAL PATIENTS • CAN BE USED WITH SMALL TUBING
TYPES OF HUMIFIERS From Fink J: Humidity and aerosol therapy. In Cairo J, Pilbeam S, editors: Mosby’s respiratory equipment, ed 8, St. Louis, 2010, Mosby.
Bubble TYPES OF HUMIDIFIERS humidifier Wick-type humidifier Heated-Bubble Pass-over (Heated)
NEBULIZATION • USED IN PATIENTS WHO NEED MORE MOISTURE • THICK SECRETION • POST-EXTUBATED PATIENTS • PT RECEIVING VERY HIGH AIR FLOW (E.G. T-PIECE) • MUST BE USED WITH LARGE, CORRUGATED TUBING “Clouds” seen from T-piece
ALL ABOUT HUMIDIFICATION FROM KNOWLEDGE TO PRACTICE
RESPIRATORY HUMIDIFICATION • American Society for Testing and Materials (ASTM) ได้ กาหนดมาตรฐานของ heated humidifier สาหรับผู้ที่ supraglottic airway ถกู bypass ไว้ว่าควรจะสามารถใหค้ วามชนื้ ไดไ้ ม่น้อยกว่า 30 mg/L ซงึ่ ใกล้เคยี งกับ British Standards Institute ทกี่ าหนด ความชนื้ ขัน้ ต่าไว้ที่ 33 mg/L
RESPIRATORY HUMIDIFICATION Exposure to humidity levels below 25 mg H2O/L for 1 hour or 30 mg/L for 24 hours or more have been associated with airway mucosal dysfunction. Therefore, a minimum of 33 mg H2O/L has been recommended for patients with an artificial airway. RESPIRATORY CARE • MAY 2012 VOL 57 NO 5 785
GAS ไอนา้ Humidification Nebulization (vaporization)+ (gas) แหง้ ความชืน้ ละอองนา้ (aerosol)+ (gas)
HUMIDIFICATION • องคป์ ระกอบสาคญั ท่ีทาใหอ้ ากาศชืน้ ไดม้ ากหรอื นอ้ ยขนึ้ อยกู่ บั SURFACE TIME TEMPERATURE
วิธีทำควำมชืน้ Humidification & Nebulization (humidity) (aerosol)
TYPE OF HUMIDIFIER Non heated or simple humidifier Heated humidifier
HUMIDIFIER 1. Simple humidifier : Blow by or pass over humidifier Bubble type humidifier Jet , under water jet humidifier Wick type humidifier 2. Heated humidifier : Heated bubble humidifier Heated wick humidifier Heated wire, fiber circuit
BLOW BY OR PASS OVER HUMIDIFIER
BUBBLE TYPE HUMIDIFIER
WICK TYPE HUMIDIFIER
HME : Heat moisture exchanger
BENNETT HEATED BUBBLE HUMIDIFIER
HEATED BUBBLE HUMIDIFIER • BOURNS HEATED HUMIDIFIER
Fisher’s heated Wick-type humidifier
WICK TYPE HUMIDIFIER
Heated humidifier
Heated humidifier
Heated humidifier
Heated humidifier
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