the benefit of heat and moisture ex changers corrected)

7/31/2019 The Benefit of Heat and Moisture Ex Changers Corrected)

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The function of upperrespiratory tract in climateconditioning:

1) heating and humidifying theinspired air

2) providing airway resistance

3) prevent dust entry throughmucociliary mechanism

Introduction


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Inspired air

- is warmed by convection

- is moistened by the evaporation from themucosal epithelium

Mucosa is cooled by evaporation

Respiratory Heat and

Water Exchange


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During normal breathing, inhaled air reachedbody temperature 37C and 100% saturatedwith water vapour (44mgH2O/L) in the mainbronchi a few cm below the carina (Walker JEet al,1961)

Isothermal saturation boundary


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During expiration, alveolar air is similar toISB

Heat is transferred back to the mucosa

The cooler the air, the less water vapour itcontainsHence, water vapour is released by

condensation

20-25% of previously exchanged heat andmoisture is returned to the mucosa(Rathgeber J & Zuchner K, 1999)


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Post laryngectomy, part of the upper airwayhas been bypassed.

Inspired air pass through a shorterrespiratory tract

ISB shifted lower downLonger part of respiratory tract not having

optimal temperature and humidity


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Mucosa becomes too dry and too cold- leading to hyperactivity of mucosa and

goblet cells- Increased sputum production, spontaneous

coughing, forced expectoration, dyspnoeaand recurrent pulmonary infections (Hilgers

Fj et al 2000)


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General principle: condensation andevaporation of water to retain water from

expired air

Heat and MoistureExchangers (HMES)


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During expiration, water vapour condenses on HMEmaterial, which has a lower temperature

Condensation also releases heatFollowing inspiration, water from HME foam

evaporated to the air, coupled with heat absorption


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Consistent use of HMEs has been proven toreduce pulmonary symptoms and voicequality. (Ackerstaff AH et al)

Use of HME is generally considered astandard in improvement of pulmonaryfunction in laryngectomized individuals

(Kaanders JH et al)


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So far all studies are done in Europe andUnited States, in cold and dry enviroment

No data about effect of HMEs in warm andhumid climate as in Malaysia and South EastAsia in general

The closest is a recent study on endotrachealtemperature and humidity in patients in awarm and dry environment and the effectof a heat and moisture exchanger(Scheenstra et al, 2010) - concluded that HMEs have beneficial clinical

effect in warm and dry environment.

WHY this study


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Respiratory symptoms worsens duringwintertime and cold climate

It has been observed that a temporary stayin subtropical climate significantly improvedpeak expiratory flow in 61 Norwegianlaryngectomees (Natvig et al, 1984)


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It is argued that an HMEs are unlikely to becontributory in warm and humid climate asthe environmental conditions are almostsimilar to the endotracheal climate

No evidence-based recommendationThis would be the first study in this region to

evaluate the direct effect of HMEs in warmand humid climate


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General objective:

To evaluate the effect of HMEs on the pulmonarysymptoms of laryngectomized patient

Objectives


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Specific objectives:

q To document pulmonary symptoms in post-laryngectomy patients before HMEs use.

q To perform an assessment using a structuredquestionnaire on respiratory symptoms in post-larygectomy patients after HMEs.


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The use of HMEs improves the pulmonarycomplaints among post laryngectomy patientin warm and humid climate

Hypothesis


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Study design: Prospective cohort

Venue: Department of ORL-HNS, PPUKM

Department of ORL-HNS, HKL

Period of study: Dec 2011- Dec 2013

Sampling size: 20

Sampling method: Convenience sampling

Methodology


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Inclusion criteria: 1) Post laryngectomy patients under ENT follow

up at HKL and HUKM

Exclusion criteria: 1) Patients with pre-existing chronic lung diseases

or obstructive lung diseases prior to laryngectomy


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Study tools:

Data collection form

Questionnaire

Methods


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Name :RN no :

Age :

Sex :Race:

Occupation :

Medical illness :

Date of diagnosis :

Date of laryngectomy:

Data Collection Form


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Symptoms Grade (1-5)1) Spontaneous cough _____

2) Sputum production _____

3) Dyspnoea _____

Grade

1- mild 2 mild moderate 3- moderate 4- moderately severe 5- severe

Frequency of sputum production

The week before trial Monday ___x

- Tuesday ___x

- Wednesday ___x

- Thursday ___x

Questionnaire 1 (BeforeHMEs)


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Symptoms Grade (1-5)

1) Spontaneous cough _____

2) Sputum production _____

3) Dyspnoea _____

Grade

1- mild 2 mild moderate 3- moderate 4- moderately severe 5-severe

Frequency of sputum production

4th week of trial Monday ___x-

Questionnaire 2 (AfterHMEs)


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Flow Chart

Study proposal approved by Ethics Committee

Patients are recruited from ENT Clinic/ Ward UKMMC& HKL

Explanation & obtain informed consent

Patients provided with the questionnaire to fill up

Fresh laryngectomees - at least4 weeks postlaryngectomy

Old laryngectomees on the same setting whenconsent is taken

HMEs are provided to patients after first


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Follow up phone calls weekly again to ensurecompliance

Follow up after 4 weeks of HME use

Patients to fill up the same questionnaire again

Data collection and compilation

Analysis of data with SPSS


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Provox HME Cassette HiFlow = 560 x RM 14 = RM 7840

LaryTube = 20 x RM 850 = RM 600

Stationary = RM 200

Phone calls = RM0.50 x 100 = RM 500

Total = RM 25540

Budget Estimation


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Walker JE, Wells REJ, Merrill EW: Heat and water exchanger inthe respiratory tract. Am j Med 1961; 30: 259-267

Rathgeber J, Zuchner K: Foundations of artificial respiration.Manual for medical doctors and nurses. Ebelsbach, AktivDruck &Verlag Gmbh, 1999

Hilgers FJ, Ackerstaff AH: Comprehensive rehabilitation aftertotal laryngectomy is more than voice alone. Folia PhoniatrLogop 2000; 52: 65-73

Ackerstaff AH, Fuller D, Irvin M, Maccracken E, Gaziano J,Stachowiak L: Multicenter study assessing effects of heat and

moisture exchanger use on respiratory symptoms and voicequality in laryngectomized individuals. Otolaryngol HeadNeck Surg 2003; 129:705-712

References


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Kaanders JH, Hordijik GJ: Carcinoma of the larynx: the Dutchnational guidelines for diagnostic, treatment, supportivecare and rehabilitatio. Radiother Oncol 2002; 63: 299-307

Scheenstra RJ, Muller SM, Hilgers FJM. Endotrachealtemperature and humidity in laryngectomized patients in

warm and dry environment and the effect of heat andmoisture exchanger. Head Neck. Oct 27

References

the benefit of heat and moisture ex changers corrected)

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