subject: Emphysema and its clinical features [print this page] Chronic bronchitis and emphysema develop over manyyears and patients are rarely symptomatic before middleage. Symptoms are initially minor, perhaps a morningcough productive of a little sputum. In some patientschronic bronchitis can remain a trivial problem, but inmany smoking-related airways obstruction coexists and thepatient then develops breathlessness. Initially breathlessnessis on exertion, but exercise capacity progressivelyand slowly deteriorates and eventually patients becomerespiratory cripples, distressed by dyspnoea even at rest.
Patients with predominant bronchitis are prone to periodicinfections. Often the infective process remains confinedto the bronchial tree, but sometimes infection involvesthe surrounding lung, with consequent pneumonia; thus,although some patients may have radiological changes ofpneumonia in association with an infective exacerbation,the majority show no change on chest X-ray. Eventuallypatients with chronic bronchitis develop severe hypoxaemia,hypercapnia and peripheral oedema-cor pulmonale(the so-called 'blue bloater'). Patients with substantialemphysema tend to be very breathless, ventilating sufficientlyto maintain normal arterial carbon dioxide andnear-normal oxygen tensions.
The development of corpulmonale is a late and terminal event in these 'pinkpuffers'. These two clinical extremes overlap; manypatients with a normal arterial carbon dioxide tensioneventually become cyanosed, but the broad clinical distinctionbetween the 'pink puffer' and the 'blue bloater'is useful. Oxygen therapy is much more difficult in thehypercapnic blue and bloated patient, sedation is morehazardous, and general anaesthesia poses greater risksbecause of postoperative sputum retention and difficultyin weaning such patients from assisted ventilation.
Somepatients have bronchial hyperreactivity, and exposure tocold air, acute temperature changes, dusts and cigarettesmoke causes increasing breathlessness, respiratory distressand wheeze.The development of cor pulmonale indicates a poorprognosis, with a 30% 5-year survival. In associationwith severe hypoxia and hypercapnia, pulmonary arterialhypertension develops and some patients also have an elevated jugular venous pressure. However, in many patientscor pulmonale is not simple cardiac failure, as cardiacoutput is frequently normal and there can be peripheraloedema without elevation of the jugular venous pressure.The mechanism of cor pulmonale remains obscure, but inpart it reflects an increase in blood volume, perhaps due tohypercapnia and hypoxia causing sodium retention bythe kidney. Cor pulmonale is unusual in the absence ofhypercapnia. There is evidence that optimum therapy andcareful follow-up of patients with cor pulmonale canproduce good results.
Physical signs
In predominantly emphysematous patients, inspiratoryairways resistance is not increased and inspiration is thereforequiet, whereas patients with predominantly chronicbronchitis have noisy breathing. To control airways collapseon expiration, patients with emphysema apply a positivepressure to the bronchial tree by the technique ofpurse-lipped breathing. As the diseases progress the physicalsigns may eventually include those of severe airwaysobstruction, hypoxia, hypercapnia and cor pulmonale.
Severe hyperinflation is indicated by a reduction in thedistance between the suprasternal notch and the cricoidcartilage, a barrel-shaped chest, and reduced abdominaloutward movement during inspiration (reflecting limiteddescent of the flattened diaphragm) coupled with pronouncedmovement of the upper chest. Patients withchronic airflow limitation often have early inspiratorycrackles which can be heard at the mouth by the examiningphysician. Weight loss is common with advancedemphysema.Patients with emphysema have translucent lungs onchest X-ray, with few vascular markings, and bullae mayalso be present.
