A STUDY TO COMPARE THE VENTILATION PATTERNS PRODUCED WITH INTERMITTENT POSITIVE PRESSURE BREATHING TO THOSE PRODUCED BY DEEP BREATHING*________ C J Eales (M Sc (Physiotherapy), Senior Lecturer, Department of Physiotherapy, University of the Wit- watersrand) A Shapiro (B Sc Physiotherapy) D Edelman (B Sc Physiotherapy) D Cohen (B Sc Physiotherapy) ABSTRACT Much research has been done on IPPB and to date little evidence has been provided to support the use of this modality. Our study was designed to investigate the ventilation pattern produced by IPPB with deep breathing compared to deep breathing only in patients who have had suspected pulmonary emboli. Ventilation images of the lungs obtained through the inhalation of the radio-active gas Krypton were used for this comparison. Twenty-three subjects were randomly as signed to one of two groups. Group A comprised 12 subjects who received the radio-active gas via IPPB. The 11 subjects in group B received the radio-active gas via the routine circuit, while doing d ia phragmatic breathing. The data were analysed using the Mann-Whitney U-test. It was shown that in patients with suspected pulmonary emboli there is no evidence that IPPB would increase alveolar ventilation more than deep brea thing exercises would.____________________________________________ INTRODUCTION B reathing makes use of a co-ordinated action of muscles to transfer volumes of gas into and out of the lungs. While this process is occurring the smallest possible am ount of oxygen must be used so that the rem ainder of the oxygen is available for use by the rest of the body. The respiratory system is then effective'. From the term “deep breathing" it is understood that by voluntarily moving regions o f the wall o f the thoracic cage, underlying lung tissue is appropriately aerated. Local aeration is normally affected by gravity. In standing the basal alveoli, i.e. the dependent areas of the lung will be p re fe re n tially aera te d 4. F o r the purpose of this study diaphragm atic breathing was taught as a means of enabling the patients to take a deep breath. Interm ittent positive pressure breathing therapy (IPP B ) is the repeated adm inistration of a series of augm ented inhalations of variable volume delivered by the subject exhaling to atm ospheric pressure ' . Claims have been put forward that IPPB is a form of assisted breathing which can be a valuable adjunct to physiotherapy in the treatm ent of respiratory disease. It is said to provide more effective aeration of the alveoli, to aid the removal o f secretions from the lungs and is a means of adm inistering drugs directly to the airways . On reviewing the literatu re on IPPB it is apparent that the clinical value as well as the therapeutic effects of IPPB remain controversial Many authorities have expressed doubt regarding the above claims. W elch et al actually felt that o ne.,of the vital factors when assessing the value of IPPB, should be the com petence, e n thusiasm and reliability of the therapist delivering the IPPB . IPPB is still frequently used in clinical situations by therapists who firmly believe that it is of great clinical value. A study was designed, by m em bers o f the Physiotherapy D epartm ent of the University of the W itw atersrand in conjunction with the D epartm ent of N uclear Medicine of the same University, to determ ine w hether IPPB would result in m ore effective alveolar ventilation than that which would occur during deep breathing only. T he common pathology that we expected to e n co u n ter during o u r research was that of pulmonary embolism, as the subjects we used were patients who had been referred to the D epartm ent of N uclear Medicine for ventilation/perfusion scanning, for suspected pulm on ary emboli. The acute response of a pulm onary throm bo-em bolus is c om plete o r partial obstruction. This has both respiratory and haem ody- namic consequences. An intra-pulm onary dead space form s as the embolic obstruction produces an area of lung w here ventilation occurs but perfusion ceases. This ventilation has no value as the non-perfused area of the lung cannot participate in the gas exchange process. As a result of the cessation of blood flow to a zone, c o n stric tion o f airspaces and airways in the affected zone occurs. Surfactant is a surface active lipoprotein required to m aintain alveolar stability. Pulm onary embolism leads to a reduction in the surfactant and alveolar collapse ensues. F rank atelectasis can be detected at 24 to 48 hours a fte r interruption o f blood flow. A rterial hypoxaemia is a fu rth er comm on consequence of pulmonary em bol ism. Infarction (death of lung tissue) rarely accom panies embolic occlusion. As IPPB and d eep breathing are often used in the clinical situation for the treatm ent of atelectasis, the patient sam ple used fo r this experiment was ideal. METHOD T he subjects were patients who presented at the N uclear M e dicine D epartm ent of the Hillbrow H ospital for routine ventila t io n / p e r f u s i o n s c a n n in g a f t e r s u s p e c t e d p u l m o n a r y e m b o lis m . Patients lor whom IPPB would be contra-indicated were excluded from the study. Any subject unable to comply with the experim ental procedure, e.g. am putees who could not manage to stand upright during the procedure, were also excluded from the study. Suitable patients were randomly allocated to one of two groups. G ro u p A com prised 12 patients who received the radioactive gas (Krypton - 81m) via IPPB. The 11 subjects in G roup B received the radio-active gas via the routine circuit while doing diaphragm atic breathing. T he Krypton-81 m g e n era to r and circuit were set up as routine (see Fig 1). Patients in group A inhaled the radio-active gas through the Bird M ark 7 circuit. A thin tube delivering the Krypton-81m gas was attached from the g en erato r to the elephant tubing of the Bird M ark 7 circuit at its distal end, facing the direction of the air flow (see Fig 2)- ABSTRAK Baie navorsing op IPDV is reeds gedoen maar min positiewe bewyse wat die gebruik van hierdie modaliteit ondersteun, is gevind. Die studie het die verskil in ventilasiepatroon tussen diep asemhaling- soefeninge alleen en IPDV met diep asemhalingsoefeninge in pa- s ie n te m e t v e r m o e d e lik e p u lm o n a le e m b o li o n d e rs o e k . Ventilasiebeelde van die longe verkry deur die inhalasie van radio-ak- tiewe Kryptongas is gebruik om die verskil aan te dui. Drie-en-twintig proefpersone is onewekansig aan een van die groepe toegewys. Groep A het bestaan uit 12 proefpersone wat die radio-ak- tiewe kryptongas deur middel van IPDVontvang het. Die 11 proefper sone in groep B het die radio-aktiewe gas tydens diafragmatiese asemhaling via die gewone baan ontvang. Die data is met behulp van die Mann-Whitney U-toets verwerk. Die resultate het getoon dat die alveolSre ventilasie in pasiente met vermoedelike emboli nie dieper was met IPDV as met diep asemhal ingsoefeninge nie. * Received February 1991. Returned after corrections August 1991. Physiotherapy, November 1991 Vol 41 no 4 Page 63 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) Mesolaser IR 01 LICENSED BY THE DIRECTOR GENERAL OF RADIATION CONTROL S P E C IA L O FFER November/December 1991 Incl. VAT R8 745,00 less 5% spot cash discount R8 307,75 Delivery free RSA • A powerful portable Ga As infra-red laser, which uses the most up to date microcomputer technology • The wave-length of 904 nm guarantees an optimal penetration depth. • Variable peak power from 0 to 30 Watt in steps of 1 Watt. • Capable of changing the frequency from 1 Hz to 5000 Hz. • Tip-touch sensor system for activating the laser beam. • Measurement of the infra-red radiation using an optical sensor. • Time clock which works only when the laser beam is activated. • Safety glasses designed for laser therapy, consisting of interference filters. These keep the visual spectrum at 95% of normal. • Unit built to comply with the international safety regulations IEC 601. MEDICAL DISTRIBUTORS (EDMS) BPK REG. NO. 5 7 /0 1 8 6 8 /0 7 (011) 29-6931 (031) 37-1501 (021) 47-4440 (012) 346-1279 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) Fig 1: Krypton-81 m generator and circuit Fig 2: Modified Bird Mark 7 circuit for inhalation of Krypton 81-m A tap, responsible for driving the generator, regulated the am ount o f Krypton-81m gas entering the Bird M ark 7 machine. T he follow ing experim ental procedure was a dhered to:- 1. T he subjects were instructed how to use the Krypton delivery circuits (routine o r with IPPB) and then given an opportunity to practice using the circuits before the inhalation of the radio-active gas. 2. All subjects were taught diaphragm atic breathing. 3. All subjects were instructed to take three b reaths during each viewing when told to do so. 4. T he inhalation of the radio-active gas then took place. Each subject was positioned in standing with the m outh level with the delivery system. T he arm s rested against the gamma cam era. The p osi tioning of the subjects was essential for the standardisation of the imaging due to the possibility of varying p a tte rn s being produced with different positions. Subjects in G ro u p A (A K iypton-81m delivered via IPPB) had nose clips on and breathed through a m outhpiece. Subjects in G ro u p B (routine adm inistration) b re ath ed through a close fitting face mask. The m outhpiece used for subjects in G ro u p A w ere changed fo r each subject while the face m ask was cleaned with disinfectant between successive subjects in G ro u p B. 5. D uring the Krypton-81 m inhalation, ventilation images w ere o b tained using the gamma cam era. An a n te rio r and p o ste rio r view were taken o f each subject. E ach view lasted as long as it took for 600,000 counts to be picked up by the com puter. T he digital image was displayed on a screen and was stored on floppy d isk e t tes fo r subsequent analysis. T he total counts over the whole area of the lung and the counts/pixel fo r each region of interest was determ ined using c om puter linked facilities. RESULTS 1. A com parison betw een the counts/pixel o f subjects using IPPB (G ro u p A ) and subjects doing d e ep breathing (G ro u p B) was m ade in subjects whose ventilation scans w ere norm al. NORMAL SUBJECTS ANT.VIEW:COUNTS/PIXEL M (Deep breathing) ^ (IPPB) CO UNTS/PIXEL RIGHT LUNQ LEFT LUNQ Fig 3: Comparison of counts/pixel in the anterior view of normal subjects. This figure depicts results of a n te rio r views o f subjects with norm al ventilation scans. Similar results were achieved with p o ste rio r views. No significant difference was d e m o n stra ted betw een the patients doing IPPB and those doing d e ep breathing. (p0.25) 2. A com parison was also m ade betw een the counts/pixel produced in those patients with pathology when using e ith e r IPPB o r d e ep breathing. SUBJECTS WITH PATHOLOGY ANT. VIEW:COUNTS/PIXEL ■ ■ (Deep breathing) H H (IPPB) CO UNTS/PIXEL RIGHT LUNG LEFT LUNG Fig 4: Comparison of counts/pixel in the anterior view o f subjects with pathology. O nce m ore, no significant difference was d e m o n stra ted betw een th e two modalities. (p0.25) Similar results w ere obtained for p o s te rio r views. DISCUSSION O u r results d e m o n stra te that th ere was no significant difference betw een d eep breathing and IPPB in improving the alveolar v e n tila tion o f patients with norm al lungs as com pared to those patients in whom pulm onary emboli had been diagnosed. It is th ere fo re not im portant which m odality is used in the trea tm e n t o f atelectasis which comm only occurs as a result o f em bolic disease. C ertain considerations should be taken into account however when deciding on the trea tm e n t modality. T he adm inistration of IPPB is costly. In practice it takes c o n sid e rable tim e to set up the equipm ent and to teach the pa tie n t the continued on page 67... Physiotherapy, November 1991 Vol 41 no 4 Page 65 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) Kantonsspltal Aarau Schweiz Um unser Team zu v e rv o lls ta n d ig e n suchen w irzum b a ld m o g lich e n Eintritt Dipl. P hysio therape uten/innen (Krankengym nasten/innen) w e lc h e bereits u b e r einige Berufser- fahrung verfugen und die gew illt sind, ih re n Beruf m it Freude u n d Einsatz auszuuben. Wir sind gerne bereit, Ihnen schriftlich odertelefo nisch auf all Ihre Fragen.sei es be zu g lic h Arbeitszeit, Einsatzmoglich- keiten, usw. Auskunftzu geben. Ihre tele- fonischen A n fra g e n w e rd e n uber die Nummer 064/21 41 41 an uns w eitergele- itet. Ihre schriftliche Bewerbung m it den ubli- chen Unterlagen richten Sie bitte an Ver- w a ltu n g Kantonsspital A arau CH-5001 Aarau/Schweiz W O R K IN T H E U N IT E D S T A T E S P H Y S IO TH E R A P IS TS EXCELLEN T JO BS We handle all licensure and visa paperwork.Minimum commitment of one year required.TRN fees paid by employer Write or phone collect: THERAPY RESOURCE NETWORK P O Box 5430 Plymouth, Michigan 48170, USA Phone (313) 455-6660 CAMBRIDGE COLLOCATION: EUROPEAN MEDICAL AND PROFESSIONAL RECRUITMENT Physiotherapy vacancies in the UK: we have vacancies for physiotherapists in the private health sector in the UK. Excellent salaries and working conditions. Please contact: Maureen Johnston Brown or Margaret Lamb, Cambridge Collocation, 191 Huntingdon Road, Cambridge CB3 ODL, England. Telephone: (0)223 276891 Fax: (0) 223 276871 Employment Agencies Act 1973 Licence No SE 118181 VAT No 538357911 PATIENT FRIENDLY ELECTROSTIMULATION. In d tm e d C V W - Two channel constant voltage stimulation - 3 current forms : continuous, spectrum, burst - Biphasic current (prevents galvanic skin effects) -Pulse duration and frequency independently adjustable - Wide variety of electrodes available ENRAF NONIUS Optim al patient com fort! LICENSED BY THE SOUTH AFRICAN RADIATION CONTROL BOARD EDI* Sandton Cape Town Tel. (011) 803-9320/1 Fax. (011) 8 03 -7 0 8 5 Tel. (021) 9 46 -4 5 6 0 Fax. (021) 948-8401 T el. (031) 5 6 1 -2 7 9 8 (PTY) LTD REG N o 90/0 42 86 /07 D u r b a n Fax. (031) 5 6 1 -4 6 5 7 * SPECIALIST SUPPLIERS TO THE PHYSIOTHERAPY PROFESSION R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) THE ELEVENTH INTERNATIONAL ___________ CONGRESS OF WCPT___________ The Barbican, London, was Ihe venue of C ongress which a t tracted over 2000 participants. W ith thirteen c oncurrent sessions operating from 09h00 to a fte r 17h00 in venues all over the centre, participants had to rush from place to place in an e n deavour lo hear those sessions that they had m arked on their program m es. As many of the sessions overlapped and as no lunch o r tea-breaks were provided, one often found oneself trying to split oneself in half in o rd e r to h e a r the key-note speakers as well as those papers of o n e ’s own special interest. T he Scientific program m e comprised scientific p aper sessions - oral and poster, audience participation sessions and clinical p re sen tation sessions. It will be impossible to sum m arise the over 500 paper and p oster presentations which covered a wide spectrum of subjects. Som e com m ents of relevance to us will be extracted from the key note and lead speakers. T h ere were four key-note papers in the four main them es of congress namely Clinical Practice, C om petency to Practice, H ealth E ducation and R esource M anagem ent. In addition th ere w ere four lead speakers in the areas of neurology, paediatrics, o rthopaedic manipulative therapy and respiratory care. T hese were all of a high sta n d ard and gave much food fo r thought. D r Ja n e Mathews, past president of A m erican Physical T herapy A ssociation gave a thought provoking ad d ress on “Shaping the future of physical therapy practice in the 21st century". A lthough th ere is a shortage of physiotherapists in many countries, she stressed that som e of the shortages were only ap p are n t and that physiotherapists were not being employed effectively in decision-m aking and c onsult ation settings, and that different countries had developed different skills to cope with their own problem s and urged us to m ake the maximum use of o u r potential in o rd e r to deliver relevant health care. P rofessor R uth G rant of the University of South A ustralia in her p a p e r o n “ O b s o le s c e n c e o r life lo n g e d u c a t i o n ” c h a lle n g e d all physiotherapists to establish w hether th eir continuing education p ro gram m es did result in improvem ent in com petence o r a change of practice. She felt that many program m es concentrated on input and did not evaluate outcom e. Professor G ra n t stressed the need for d e v e lo p in g p r o b le m - i d e n t if ic a t io n a n d p ro b le m - s o lv in g sk ills in o rd e r to prepare students for independent, first contact practice. Professor Keith T ones of Leeds Polytechnic stressed the m ajor role the physiotherapist has in educating patients, their carers and the public at large in health prom otion. This will require skills in teaching, counselling, consulting and empow ering clients. T he final key-note lecture on “Econom ics, the road to b e tte r physiotherapy” was delivered by P rofessor Gavin M ooney o f the U niversity of A berdeen. His main them e was the im portance of using resources in such a way as to provide a healthy population. P rofessor L ance Twomey from Australia, the lead speaker in o rthopaedic m anipulative therapy, spoke on the age of reason in m usculo-skeletal physiotherapy. H e stressed the need for m ovement following injury to prevent atrophy and degeneration of a rticular ...continued from page 65 correct usage. An oxygen source must be available and oxygen is an expensive modality. T he venue of IPPB adm inistration is limited to places w here oxygen u nder pressure is available to drive the m achine. In contrast, d eep breathing exercises require no special eq u ip m ent. Thus, to w arrant the use of IPPB above the use of deep breathing exercises, evidence of the increased beneficial effects of IPPB m ust be proven. O u r research showed no such benefit. Thus, contrary to the claims put forward to support the use of 2 IPPB to increase alveolar ventilation , we feel that d eep breathing exercises would be just as effective. cartilage and underlying bone. H e w arned against bedrest, a n alg e sics, co rsets and rest in the trea tm e n t o f back injuries and re c o m m ended 8 -1 0 hours of daily intensive physiotherapy fo r 3-^1 weeks fo r chronic injury. T h e lea d s p e a k e r in n e u r o lo g y w a s C a ro ly n G o w la n d from M cM aster U niversity who spoke of the need to de m o n stra te the effectiveness of trea tm e n t and urged research in this area as well as objective clinicaf studies. The use o f valid m easurem ent and the design of m easurem ent tools is essential. David Scrutton of L ondon continued the above them e and urged the replacem ent of technique-dom inated trea tm e n t in paediatrics fo r aim -oriented m anagem ent. A lthough he did not suggest that c u rre n t trea tm e n t m ethods should be discarded, he urged us to becom e m ore analytical and critical of o u r techniques. B arbara W eb b e r o f B rom pton also stressed the need for research as well as th e c ritic a l e v a lu a tio n o f re s e a r c h lite r a tu r e in c h e s t physiotherapy so as not to be tem pted to extrapolate findings to a b ro a d er spectrum of patients than those used in the study. T he audience participation sessions a ttra c te d m uch interest as delegates were able lo discuss non clinical issues of international interest in an open forum . Topics discussed o r d eb ated with insight and o ften with hum our, were: • All physiotherapists w ho leach should be actively involved in clinical practice. • How a re the needs for physiotherapy identified a nd met w o rld wide? • D o physiotherapists involved in u n d e rg ra d u a te and post-grad- u ate physiotherapy education re q u ire a qualification in e d u c a tion? • How is specialisation defined and does it benefit the p a tient? How can specialists be developed and recognised? • Assistants/A ides should be m ulti-disciplinary w orkers. W hat a re the im plications fo r training in different countries? • On w hat basis has the role of the physiotherapist changed in different countries in the past 10-15 years. The clinical p re sentation sessions covered subjects such as anky losing spondylitis, head injuries, spinal injuries, conductive e d u c a tio n , c y stic f ib ro s is , c h e s t p h y s io t h e r a p y in c h il d r e n , m u s c u la r dystrophy a nd burns. Finally in addition to all the above, several special in te rest group m eetings w ere held as well as discussion sessions on a variety of subjects. It would be most helpful if those South A frican delegates who atte n d ed these m eetings would provide the N E C with short rep o rts and for possible inclusion in o u r journal. T he sessions are: • Forum on physiotherapy research. • W orking in developing countries. • Planning session for the Private P ra c titio n e rs’ C ongress in H ong Kong in 1992. • M anpow er planning for physiotherapy - should W C P T be in volved and how? • Review of W C P T w orkshops on trea tm e n t of C P/role of C B R . J C Beenhakker; S Irwin-Carruthers ♦ CONCLUSION In patients with suspected pulm onary emboli th ere is n o evidence th at IPPB will increase alveolar ventilation m ore than d eep breathing exercises. REFERENCES 1. R e sp ira to ry C are: A g u id e to C lin ica l P ra ctice. Ed Burton GG, Hodgkin JE. 2nd ed. JB Lippincott Company. Philadelphia, 1984:530. 2. Downie PA. ed. C a s h 's T e x tb o o k o f Chest, H e a r t a n d V ascular D is o rd e r f o r P h y sio th er apists. 3rd ed. J Fletcher and Son, Norwich. 1983:183. 3. Pierce AK ed .C o n fe re n ce on th e S c ie n tific B a sis o f R e sp ira to ry T hera p y. Temple University Conference Centre of Sugarloaf, Pennsylvania, A m R e v R e s p ir D is 1974:110(6):part 2. 4. JB West. V entilation I B lo o d F lo w a n d G a s E x ch a n g e. 3rd ed. Blackwell Scientific Publications, 1978:39. 5. Welch MA et al. Methods of Intermittent Positive Pressure Breathing. C h est 1980:78:463. ♦ Physiotherapy, November 1991 Vol 41 no 4 Page 67 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. )