Methods of Oxygen Therapyin a Tracheostomised Patient

(PRELIMINARY REPORT)

RAMESH CHANDRA,Durgapur,

Campbell (1965) has described thatin impaired respiratory function, arte-rial pCO2 is below 60 mm, Hg. andarterial pCO2 is above 49 mm. Hg. Theonly condition other than respiratoryfailure in which blood pCO2 is raised isnon-respiratory or metabolic alkalosisand the only condition other than therespiratory failure having reducedarterial p02 is right to' left cardiovas-cular shunt. Relief of hypoxia (whichmay be present due to various causesin a tracheos-tomised patient) is urgen-tly needed by administering oxygen.But one has to remember that Carbon-di-Oxide has five major effects on thebrain (Evans and Grey 1962) :

(i) CO2 tension of the arterial bloodis the major factor governingthe cerebral blood flow.

(ii) It may be presumed that CO2exerts the inert gas narcoticeffect.

(iii) CO2 influences the excitability ofDr. Ramesh Chandra, M.S. (E.N.T.), D.L.O.,Sr. ENT Surgeon, Durgapur Steel PlantHospital, Durgapur-5. (West Bengal). Thispaper was read before the Durgapur Branchof Indian Medical Association on 4.9.66. andreceived for publication on 6.9.66.

the cerebral neurones particul-arly those of the reticulo-acti-vating system and the hypotha-lamus.

(iv) CO2 is the main factor controll-ing the intracellular pH of theneurones. Changes is pH causecomplex secondary changes inthe cell.

(v) A rise of pCO2 increases C.S.F.pressure as a result of increasingcerebral flow which increasesthe dimensions of cerebralcapillary bed.

These five effects interact in such away that the total effect of CO2 uponthe brain is complicated. Normal pCO2is 36-44 mm. "Hg. pCO2 of 100 mm.Hg. causes confusion bordering uponloss of consciousness. pCo2 of 120 mm.Hg. is usually associated with coma.Anoxia not only stops the machine butwrecks the machinery (Kodicek, 1960).Campbell (1965) noted that tissuehypoxia due to lung disease can beabolished by giving moderate relief ofhypoxemia which is accomplished byraising 02 concentration of the inspiredair by only 4-8%.

121

Indication for Oxygen Therapy In aTracheostomised Patient.1. Affection of higher centres

Prolonged comatosed state e. g.barbiturate poisoning, coal gaspoisoning, cerebrovascular acci-dents, head injuries, encephalitisetc.

2. Affection of chest walli) Operative instabilityii) Traumatic instability

3. Air way obstructioni) Inflammatory obstruction e.g.

Laryngotracheo-bronchitis.ii) Repeated bronchial spasms

due to irritation of tracheo-bronchial mucosa or neurogenicas in tetanus.

iii) Edematuous obstructions e.g.allergy, inhalation of steam,irritating gases of chemicals,edema of renal or cardiacfailure or over doze of potas-sium iodide.

iv) Traumatic obstructions e. g.repeated bronchoscopy for re-moval of foreign body.

v) Tumours of tracheobronchialtree.

vi) Abdominal surgery with lowrespiratory reserve.

vii) Cardiac surgery.4. Affection of lung parenchyma.

i) Chronic bronchitis.ii) Severe emphysema.

iii) Pulmonary edema.iv) Severe pneumonia.

5. Affection of mediastinumi) Mediastinal emphysema.

ii) Growths causing respiratoryinsufficiency.

Methods of Administering Oxygen in aTracheostomised Patient.

The following words of Christie(1964), quoted by Campbell must be

remembered "Deaths from respiratoryfailure can almost always be delayedor prevented, provided that the physi-cian or surgeon is aware of the hazardsinvolved and provided that adequatefacilities are available."

Various methods of administeringoxygen have been described in a patientwith respiratory failure on whomtracheostomy has not been done. Vari-ous types of masks, face tents, head-hoods, endotracheal tubes, nasophary.ngeal insufflation by catheter, oxygentent and funnel over the face are in use.Their advantages and disadvantageshave been described.

Unfortunately administration ofoxygen in tracheostomised patients hasnot received much attention. Thefollowing methods are available :--

1. Cuffed Tracheostomy Tube:This method is usually used when-

ever patient is also given anesthesia e.g.during operation on larynx etc. Whenan urgent tracheostomy is done in acase of cyanosed respiratory paralysiscase, oxygen is administered underpositive pressure through an anaestheticmachine, till cyanosis disappears andsubsequently IPPR is given by theavailable respirator. This method gives100% oxygen and is not indicated forpatients with cardiopulmonary disease,even for those with severe impairmentof diffusion, since maximal oxygenationof the arterial blood can be attainedwith lower concentration of Co2-unless there is venous to arterial shunt(Comroe et al 1962)

Such a method of oxygen therapyis not practicable in wards where it hasto be continued for long periods exceptin cases who require IPPR withoxygen.

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2. Catheter Technique:

Insertion of a catheter into thetracheostomy tube and administeringoxygen is the method commonly emp-loyed without knowing the seriousdisadvantages it offers to a needypatient. The introduction of cathetercauses stenosis of the air way as itoccupies space and allows oxygen topass one way towards the lung whilethe moribund patient has to respirethrough the space left around thecatheter which offers resistance. Thisnarrowing is more marked in childrenwho wear small tracheostomy tubes.The blast of the oxygen from thecatheter end is towards the lung whilethe weak expiratory blast is in oppositedirection thus adding to resistancealready produced by the introductionof the catheter. Thirdly, the blast ofoxygen impinges on the tracheal walldrying the mucous and causing crusta-tions which are inimical to a tracheastomised patient. Noting all theseserious dis-advantages, the cathetertechnique must be discarded. Theodos(1965) has cautioned against use ofcatheter into the tracheostomy tubebecause insertion of it will produceobstruction and turbulance in the flowof expired air.

3. Tracheal InsufflationComroe et. al. (1962) have descri-

bed "Tracheal Insufllation" of oxygenintroduced by Meltzer and Auer.Oxygen is passed by keeping the cat-heter tip near the bifurcation of tracheato produce high alveolar oxygen con-centration in an unconscious non-breathing patients. This form of oxygenadministration should be, used only inan emergency and for brief periodssince it makes . no. provision for CO2elimination i. er oir •mf gas is always

downwards with no expiratory phase.

4. Oxygen Tent :(Comroe et. al. 1962, Bilimoria-

1958) Full oxygen tent must contain amotor blower and cooling unit to keepthe temperature of the enclosed airfrom rising. This method involveswaste of oxygen. Great initial flow isrequired to attain an oxygen concent-ration of 40-60%, then the flow is to bereduced but it again rapidly falls to21% when tent is opened. No tent isleak proof. A flow of 12 L/mt. oxygenmust escape around the edges of thetent. For these reasons the full oxygentent is most uneconomical. It must beused in an institution where all facili-ties exist. Theodos (1965) has alsoobserved that concentration of oxygenin a tent is difficult to maintain becauseof frequent interference consequent onpost-operative care.

5. "T" tube connectionA gynecologist c)lleague of the

author suggested use of "T" tube—onelimb of it, connected to a oxygenreservoir and the other end attached tothe inner tube of the tracheostomy tubewhich the patient wears. As the dragg-ing force of the oxygen carrying tubewill cause undue rubbing of tracheos.•tomy tube on the inner wall of tracheaand also diameter of it will reduce theopening through which the patientrespires causing resistance to air flow,this method cannot be recommended.6. Funnel method:

A funnel kept just above the trac-heostomy tube and connected to aoxygen reservoir can serve the purposeof removing hypoxemia without causingrespiratory embarasment. It has notbeen worked out so far as to how muchbxy&en reaches the alveoli and whatpercentage of oxygezt, requirement is

Methods of Oxygen Therapy/'Vieth Char«dra 123

satisfied when a funnel is used todeliver in a tracheostomised patient.10% oxygen is given to the alveoliwhen the funnel is kept over the noseand mouth in a non-tracheostomised-patient. As dead-space above thelarynx is bypassed by tracheostomy,

-the funnel over the tracheostomy willgive more than 10% of oxygen to thelung alveoli. Some amount of oxygenwill definitely go out from the edges ofthe funnel leading to some waste of-oxygen.

To hold the funnel over the trac-heostomy opening in any position ofthe patient, author has designed "oxy-gen Funnel and Clamp" (Fig. 1). Thiscan be fixed on the angled-iron sides ofThe patient's cot anywhere and funnelcan be adjusted over the neck in anyposition of the patient. Two sizedfunnels are provided to suit the neck of

-the patient and can be removed forsterlization. Apart from administrationof oxygen, the funnel can be used forhumidification and aerosol therapy for

-the care of tracheo-bronchial tree. It

has been found that oozing of blood(luring any operation, including thoseon the ear, diminishes if blood is maderich with oxygen. When an operationon the ear is done even under localanaesthesia, the "Oxygen funnel" canbe easily placed over the face of thepatient. This is an added advantagethough not connected with a tracheos-tomised patient. This funnel is cheaperthan other available marketted funnels(Richard, USA Instrument Catalogue)for use in operation theatre. In addi-tion this equipment can be used, afterremoval of the funnel, to fasten thetube leading to IPP respirator fromthe patient so that there is no draggingon the cuffed tracheostomy tube whicha patient requiring assisted respirationwears (Spalding 1966, Fig. 2). Trans-portation of the patient on the cot isalso facilitated by such arrangementavoiding accidental detachment of thetube from the respirator (Wilson- 1966.)This equipment can also be used as ascreen frame, after detaching the

Fig. I Oxygen funnel connected to a oxygenreservoir and clamped to the side of patient'scot and positioned over the tracheostomy

opening.

Fig. 2 Tube leading to 1 PPR from the pati-ent fastened to the transverse arm to avoiddragging of the cuffed tracheastomy tubeand facilitate transportation of the patient

on the cot.

124 Ind. J. Otol. Vol. XVII!, No. 4, December 1966

funnel, during operations by fixing iton the operation table.7. Tracheostomy mask:

Theodos (1965) has described useof tracheostomy mask which can beput over the tracheostomy opening andtied around the neck. Author has notseen or come across detailed literatureabout this mask. But he has designedand got it fabricated from a thinaluminium sheet (Fig. 4). It has asmall door in its front face for inspec-tion and suction from the tracheostomytube, which can be kept closed duringoxygen therapy. Oxygen comes in froma lead at one side of the mask. Fewholes on the other side serve as outletsfor the gases. Humidifier/aerosol canbe connected to this mask, if desired.Patient has to wear it over the gauzepads around the tracheostomy tube toprevent leakage from the sides. Wast-age of oxygen is minimized by wearing

Fig. 3 Tracheostomy mask on the paient'sneck. (child size)

this mask. The mask can be changedwhen soiled by patient's secretions andcan be easily sterilized by boiling.Oxygen from its inlet into the maskpasses over the tracheostomy opening,.from which patient breathes in andout, to the opposite side and passesout of the mask from the multiple-holes. It carries out expired air alongwith it and during inspiration enters.the lung without carrying expired CO2.In this way higher percentage of 02 isgiven to a patient without much beingwasted. Advantages of the tracheos-tomy masks can be summarized asfollows :(a) Comfortable to wear as it is light.

Aluminium sheet can be replacedby boilable plastic material.

(b) Can be easily tied around theneck in any position of thepatient.

(c) When soiled by secretions, can betaken off the neck quickly andreplaced by another mask.

(d) Higher concentration of oxygencan be given without much wasteof oxygen.

(e) Patient does not breathe in his,own expired air.

(f) Humidification/aerosol can begiven along with it.

(g) Tracheobronchial toilet can bedone by opening the front trapdoor.

(h) Low cost.(i) Patient can be nursed easily.

) Does not interfere with the trac-heostomy tube and thus no fric-tion with trachea is caused by thetube.

(k) It prevents enterance of insectsetc.

The disadvantage of the tracheos-

Methods of Oxygen Therapy/Ramesh Chandra 125

tomy mask will be difficulty in wearingit in infants with small neck.

CONCLUSION

Author shares the opinion of othersthat oxygen therapy to the tracheosto-mised patients by catheter techniqueshould be condemned. IPPR is advis-able only in certain circumstances. Ifoxygen tent is used, large quantity ofoxygen is wasted and proper percent-age of oxygen cannot be maintained allthe time. Administration of oxygen byfunnel method is advisable, but use oftracheostomy mask seems to be ideal.

SUMMARY

Indication for oxygen therapy intracheostomised patient have beendescribed along with methods of admi-nistration of oxygen. Author hasdesigned "Oxygen funnel and Clamp"and "Tracheostomy Mask" for oxygentherapy and has discussed its meritsand demerits.

ACKNOWLEDGMENT

The author wishes to thank ShriR. K. Chatterjee, General Manager,and Dr. P. K. Chatterjee, Chief Medi-cal Officer for giving permission topublish this paper. He is indebted toShri Chandra Mohan, Assistant Direc-tor and Shri L.A. Chetliar Sr. Scientistof Central Mechanical EngineeringResearch Institute, Durgapur, for help-ing in fabrication of the equipments.He is also thankful to Dr. N. N. Roy,Junior, E.N.T. Surgeon, for helpinghim in various ways, and to Shri P. S.

Raju, Photographer, for taking photo-graphs.

REFERENCES

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2. Christie, R. V. : Editorial com-ment, B.M.J. -1 : 1447, 1965

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