efers to a chemical engineers’ handbook — “ two- He ^ cocurrent upflow” and “ Mist flow, in which liquid P^arried as fine drops by the gas phase. D a ta indicate 's * this probably occurs for superficial gas velocities r about 70 ft./sec. ( > 2 500 cm/sec.)” . D e K ock °iVQ76)1 ° n the other hand, feels that the two narrower ncni joining to form a larger bore trachea make for all imPortant and necessary acceleration and in- r e a s e d velocity with respect to gas exit and coughing. In addition Leith (1968),5 reminds us of the mucocil- ■ v clearance system which extends to the remotest 'arts of the lungs as well as two other clearance e c h a n i s m s of the lung, viz. phagacytosis and lymphatic Irainage- H e also draws our attention to one more r (cresting possibility. The alveolar lin in g ’s surface te n s io n falls to very low values when the area is decreas- •ng i.e. with expiration. This low-tension surface is thus drawn upwards and m ight possibly also be a clearance m e c h a n i s m . Sighing and slow relaxed expiration could therefore possibly be of great significance to the physio- herapist. Thus it would seem that prim ary requisites for efficient coughing are: 1 A mechanically sound anatomy, patent trachea and airways, ensuring dynamic compression. Muscle con­ traction must literally squeeze the lungs. The role the abdominal muscles can play in aiding breathing and lung clearance, albeit reflex, must be acknow­ ledged. Bethune (1975).“ 2 . Velocity sufficient to create “ mist-pumping” . Raising the intrathoracic pressure can lead to an increased expulsive gas phase which would carry secretions from the trachea to the exterior. With all these factors in m ind one must now apply them to specific pathologies and one can easily see that specific techniques must be evolved for the various pathologies. Firstly, let us look at the patient on the respirator. Opie and Spalding (1958),1 have shown that the life- saving benefits of physiotherapy for patients receiving intermittent positive-pressure respiration are due to direct squeezing o f the lung beneath the hands, and are not due to the rate of expiratory flow. These patients still need to be suctioned; increased expiratory flow with physiotherapy is not capable of expelling loose secretions rough the tracheostome. Secondly, coughing in the unconscious patient may be reflexly evoked by applying sustained stretch to the abdominal muscles, Bethune (1975)/’ This is an ex­ tremely useful technique w ith which to be acquainted. Thirdly, the routine post-operative accumulation of increased mucous secretions can be effectively removed by coughing after m axim um inspiration, whereas, if there is any evidence of diffuse obstructive airways syn­ drome where the equal pressure point moves proximally, |t would seem wise to cough on a lesser volume of inspired air. Fourthly, patients who suffer from diffuse obstructive airways syndrome should be instructed to cough with •heir necks in an extended position. This position w ith­ draws the affected trachea from the thorax, “ stretches it out” so to speak, facilitating expectoration, D e K ock (1976).4 Clinically this is a most effective manoeuvre. Finally the value o f postural drainage and gentle diaphragmatic breathing emphasising the expiratory Phase in aiding the flow of sections to the area of the cough reflex should be neither under-estimated nor ‘Wgotten. JUNIE 1977 References 1. Schamroth, L. (1976), Personal Experiences. S. A fr. M ed. Jn l., 50, 297. 2. Comroe, J. H . (1974), Physiology of Respiration. 2nd Ed.: Chicago, Year Book M edical Publishers, Inc. 3. Brink, A . J., De K ock, M . A . (1973), Hart- en Long- Siektes. Cape Town, Nasou. 4. D e Kock, M . A. (1976), Personal C om m unication, current research. 5. Leith, D . E. (1968), Cough. Phys. Ther. A m . Jn l., 48, 5, 439. 6. Bethune, D . D . (1975), Neurophysiological facilita­ tion o f respiration of the unconscious adult patient. Physiother. Jn l. Can. Ass., 27, 5, 241. 7. Opie, L. H ., Spalding, J. M . K . (1958), Chest Physio­ therapy during Interm ittent Positive-Pressure Respi­ ration. Lancet, II, 7048, 671. 7 BOOK REVIEW Respiratory Physiotherapy and Pulm onary Care, by U lla Ingwersen (M unksgaard, Copenhagen, 1976), John Wiley and Sons, N ew York/London/Sydney/Toronto. Price— Danish kroner 60,00. In his foreword to this book Prof. H . Anderson, Surgeon-in-Chief of the Thoracic Surgical D epartm ent, Copenhagen C ounty Hospital in G entofte, Hellerup, said: “ Respiratory physical therapy is a comparatively new speciality in D enm ark. It was first used by thoracic surgeons, who now regard this speciality as indispensable, later by chest specialists and most recently by orthopaed­ ists, who still have not yet begun to use it suffiicently.” U lla Ingwersen describes the various techniques em­ ployed, fully and in good detail. I t is a pity that there is no mention of the mechanical aids such as I.P.P.B . and ultra-sonic nebulizers that can be of great value in the physiotherapy treatment of some selected cases. A lot of emphasis is placed on huffing — “ a long, powerful expiration with open vocal cords by means of which the patient, so to speak, “ rolls” the secretions up w ithout any great effort and without an actual cough. Huffing should be considered the most im portant point in the treatment o f patients with pulm onary secretions.” I feel that this method has got some value in patients with a tension pneumothorax, severe air trapping and some thoracic surgical conditions but certainly the most effective way of removing secretions from the lung is by coughing. Huffing may cause pronounced increased bronchospasm. The section on treatment of patients in Intensive Care Units is not adequately covered and no m ention is made of the treatment o f chest conditions o f children in medical intensive care units. From the point o f view of physiotherapists in South A frica, we employ a m uch more advanced and sophisti­ cated level of respiratory therapy. C . E A L E S. C O R R E C T IO N : Contents of S.A.S.P. Journals 1975 and 1976 J U N E 1976 M anagem ent of Amputees, a Team Approach Bernice Kegel, B.Sc.Physio.(Rand), R.P.T. F I S I O T E R A P I E 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. )