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of the instrument considerably; the endoscope can beintroduced in most cases, but manipulation beyond thepylorus may be impossible. 12 The endoscopist’s field of viewis often restricted by the loss of flexibility and limitation ofthe viewing aperture. The ultrasound probe has highfrequency and therefore high resolution but a small field ofview and limited penetration; visualisation of the pancreasmay similarly be inadequate in up to 30% of cases and of theliver is always incomplete.13Thus the ultrasound endoscope is an expensive

instrument which cannot be used for regular endoscopybecause of its inherent inflexibility and viewing limitations;close cooperation is required between an experiencedendoscopist and sonographer. Until the technologybecomes available that would allow ultrasound imaging ofintestinal mucosa and of adjacent structures at the time ofroutine upper gastrointestinal endoscopy, echo-endoscopywill remain a somewhat uneasy marriage of two techniques,best restricted to research centres.

SPEECH WITH A CUFFED TRACHEOSTOMYTUBE

A FUNDAMENTAL requirement for speech is a supply ofair to the larynx, normally furnished by the bellows action ofthe lungs. A tracheostomy diverts the flow of air so that itdoes not pass through the larynx and therefore speech iscompromised. The almost universal popularity of the

Negus pattern of tracheostomy tube lies, to a large extent, inthe fact that it has an inner tube with a valve mechanismwhich closes on expiration. As a result, air is directed aroundthe tube and therefore into the larynx, allowing phonation.In the Alderhay pattern of tube, used for infants and smallchildren, a fenestration in the inner and outer tubes allowsflow through, as well as around, the tube when the

expiratory valve closes. This form of "speaking" tube is notsuitable for patients who require a tracheostomy tube withan inflated cuff, since the cuff prevents air flow around thetube. Most patients with cuffed tracheostomy tubes arereceiving intermittent positive-pressure ventilation, whichalso precludes the use of a fenestrated tube. Many patientson ventilators are sedated or unconscious, and others onlyrequire short-term ventilation; these groups can easilymanage without speech. However, for patients who spendweeks or even months dependent on assisted ventilation, thefrustration of being unable to communicate easily is aconsiderable burden.

Cuffed tracheostomy tubes allowing speech were firstintroduced in the 1960s.12 One of the first models to be

produced commercially was the ’Pitt Trach’ (NationalCatheter Corporation), developed at the University ofPittsburg.3 At about the same time, Portex launched the’Vocalaid’ tube, which was assessed by Kluin et al4 in 19ventilator patients, 14 of whom achieved intelligible speech.Sparker and colleagues have lately compared the vocalaid

12. Lux G, Heyder N, Lutz H, Demling L. Endoscopic ultrasonography—technique,orientation and diagnostic possibilities. Endoscopy 1982; 14: 220-25.

13. Sivak MV, Kaufman A. Endoscopic ultrasonography in the differential diagnosis ofpancreatic disease. A preliminary report Scand J Gastroenterol 1986; 123 (suppl):130-34.

1. Hesser O, Rehder K, Caveth SW Tracheostomy canula for speaking during artificialrespiration. Anaesthesiology 1964; 25: 719-21.

2. Whitlock RML. A means of speaking with a cuffed tracheostomy tube. Br Med J 1967;iii: 547.

3. Safar P, Grenvik A. Speaking cuffed tracheostomy tube. Crit Care Med 1975; 3: 23-26.4. Kluin KJ, Maynard F, Bogdasarian RS. The patient requiring mechanical ventilatory

support use of cuffed "talk" tube to establish phonation. Otolaryngol Head NeckSurg 1984; 92: 625-27.

with a similar device, the ’Communitrach I’ (ImplantTechnology), in 19 patients,5 15 of whom were able tocommunicate effectively with these devices. Both types werefound to be satisfactory, but the communitrach was

preferred. All these tubes work on the same principle. Anextra channel is provided that opens above the cuff and isconnected to an external humidified air/oxygen supplywhich acts as a substitute for the pulmonary bellows. An airflow of between 2 and 101/min is required, a balance beingstruck between speech clarity and patient comfort. 3,6Increased flow rates produce a better voice, but above 101/min most patients experience considerable discomfort.The external air supply should not be connected to the gassupply in a newly created tracheostomy because air tends toescape through the incision, but after about 48 h the systemshould function properly.3 3Another device, the ’Ventivoice’ (Bear Medical Systems),

works on a different principle, whereby gas in introducedinto the pharynx under pressure, via a nasal catheter. Thegas supply can be activated either by a finger switch, or byone mounted on the forehead which can be operated bywrinkling the skin. Sparker et all also tried the ventivoice,but found it disappointing.

WHAT HAPPENS TO THE LEFT VENTRICLEDURING PTCA?

IN 1698 Chirac reported the effect of coronary occlusionon left ventricular performance; after coronary arteryligation in a dog he noted that the heart soon stoppedbeating.7 The introduction of percutaneous transluminalcoronary angioplasty for the treatment of obstructive

coronary disease has provided a unique model of transientcontrolled coronary occlusion in man.8 Left ventricular

performance during balloon coronary occlusion hastherefore been studied by means of echocardiogÌ’aphy,9-11cine ventriculography,12,13 or, more recently, intravenousdigital subtraction angiography.14 .

Within 20 s of the onset of balloon inflation in the anterior

descending coronary artery, left ventricular filling is altered,with a shift of the diastolic pressure-volume relation

upwards and to the right implying a decrease in chambercompliance.15 Regional asynergy becomes apparent and

5. Sparker AW, Robbins KT, Nevlud GN, Watkins CN, Jahrsdoerfer RA. Aprospective evaluation of speaking tracheostomy tubes for ventilator dependentpatients. Laryngoscope 1987; 98: 89-92.

6. Hansen A. Vocalisation via a cuffed tracheostomy tube. Anaesthesia 1975; 30: 78-79.7. Chirac P. De motu cordis. Adversena analynca, 1698: 121.8. Serruys PW, Meester GT, eds. Coronary angioplasty: a controlled model for

ischaemia. Dordrecht: Martinus Nijhoff, 1986.9. Visser CA, David GK, Kan G, et al. Two-dimensional echocardiography during

percutaneous transluminal coronary angioplasty. Am Heart J 1986; 111: 1035-41.10. Wohlgelernter D, Cleman M, Highman HA, et al. Regional myocardial dysfunction

during coronary angioplasty evaluation by 2-dimensional echocardiography and12 lead electrocardiography. J Am Coll Cardiol 1986; 7: 1245-54

11. Alam M, Khaja F, Brymer J, Marzelli M, Goldstein S. Echocardiographic evaluationof left ventricular function during coronary artery angioplasty. Am J Cardiol 1986;57: 20-25.

12. Serruys PW, Wijns W, Van der Brand M, et al. Left ventricular performance, regionalblood flow, wall motion and lactate metabolism during transluminal angioplastyCirculation 1984; 70: 25-36.

13. Doorey AJ, Mehmel HC, Schwarz FX, Kubler W. Amelioration by nitroglycerin ofleft ventncular ischaemia induced by percutaneous transluminal coronary

angioplasty: assessment by haemodynamic variables and left ventriculography.J Am Coll Cardiol 1984; 6: 267-74.

14. Norell MS, Lyons J, Gardener J, Layton C, Balcon R. Investigation of left ventricularcontraction during coronary angioplasty: feasibility and results using digitalsubtraction ventriculography. Proceedings of the 16th Annual Symposium of theTexas Heart Institute. International Symposium on Interventional Cardiology: 87(abstr).

15. Wijns W, Serruys PW, Slager CJ, et al. Effects of coronary occlusion duringpercutaneous transluminal angioplasty in humans on left ventricular chamberstiffness and regional diastolic pressure-radius relations. J Am Coll Cardiol 1986; 7:455-63.