Hypoxia and Thoracic Scoliosis

Abstract

The incidence of lobar pneumonia rose with age, segmental pneumonia was most frequent in young children, and acute bronchitis was most often found in the young and the elderly. Similar facts were observed in the report of the College of General Practitioners (1956). These three clinical conditions also had quite dilTerent disability rates at follow-up. The highest disability rate was found in those who had suffered from acute bronchitis (71 %), and the lowest in those with segmental pneumonias (16%); that for lobar pneumonia was in between (42%). It was also found that the lower social classes were more likely to suffer from these acute chest infections, whereas only II% of the practice population belonged to classes IV and V; 44% of the patients with these chest infections were in these two groups.When the disabled group was analysed in an attempt to answer the questions who was disabled and why, some pointers emerged. Of those disabled 63% (118 out of 187) were over the age of 40. The disability rate for males (47%) was only a little higher than that for females (40%). It was very difficult to interpret the role of smoking because while 90% of disabled men were smokers (but then more than 76% of men in the London area are smokers) only 40% of the disabled women were srmokers (in London 48% of women are smokers).It may well be that men were more susceptible to the effects of smoking and that they smoked more, or that women found it easier to give up once symptoms developed. More studies are obviously necessary to clear up this point.The disabled group contained 53 % in social classes IV and V. whereas only 11% of the practice were in these two classes. It seems fairly definite that the lower social groups are more likely to suffer disability after pneumonias and acute bronchitis. A previous history of chest trouble also had a marked adverse effect on the prognosis. The disability rate in those with such a history was 71 %-almost twice that for the whole series, which was 40%.A picture thus builds up that those most likely to develop disabilities from chest infections are men over 40 who smoke, who belong to social classes TV and V, and who have a previous history of chest troubles. There are also other factors which have not been taken into account here, but which must be considered-the environmental effects, such as atmospheric pollution, and occupational risks and genetic and familial influences. The treatment given may also play a part in influencing the ultimate course of the condition. All these facts require further assessment by planned long-term studies before prevention can be attempted. Summary 424 patients who suffered from pneumonia or acute bronchitis in 1949-54 were followed up for 5 to 10 years and reassessed functionally in 1959.As many as 43 % were considered to be disabled according to the method of grading used, 9% were complete invalids, and 24 had died during the acute illness. This rate of disability was more than twice that present (21 %) before the infection S to 10 years earlier.Three d...

Alveolar-Arterial Gradients and Small Airways in Kyphoscoliosis

“…With regard to kyphoscoliotic patients with bronchitic superimposition [6,21,28], the respiratory obstructive situ ation could be determined by the bronchi al infective component, rather than by the kyphoscoliosis itself. In other cases [2,10,12,18,20,26] it is necessary to notice that the indices of bronchial obstruction ap pear in few of the subjects belonging to the respective case studies and with values which are not as altered as the indices of the restrictive ventilatory disturbances are.…”

“…Arterial hypoxemia represents the most common alteration of gas exchange in ky phoscoliosis [14,20,21,27], Initially, the arterial hypoxemia is associated with nor mocapnia [13]. Afterwards, at times after many years, hypercapnia will appear [19, …”

“…The reduc tion in tidal volume causes a significant portion of each breath to be utilized in ventilating the anatomical dead space, while an insufficient volume of air venti lates the alveoli, which results in deadspace hyperventilation and alveolar hy poventilation [1], Various researchers have observed, in kyphoscoliosis, the presence of anomalies in the distribution of ventilation and per fusion in various regions of the lungs, with alterations of the ventilation-perfusion ra tio^, 13,[19][20][21],…”

Idiopathic scoliosis. Gas exchange and the age dependence of arterial blood gases.

“…Blood gas abnormalities in scoliosis have been attributed to alveolar hypoventilation as a result of a ventilatory pattern of small tidal volumes (VT)' and a high respiratory frequency (3)(4)(5). However, the most common blood gas abnormality is a reduced arterial oxygen tension (Pao2) with a normal arterial carbon dioxide tension (Paco2) (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). The reduced Pao2 and elevated alveolar-arterial oxygen differences (AaDo2), and dead space (VD)-tidal volume ratios (VD/VT) are indicative of ventilation/blood flow maldistribution (1)(2)(3)(6)(7)(8)(9)(10).…”

“…However, the most common blood gas abnormality is a reduced arterial oxygen tension (Pao2) with a normal arterial carbon dioxide tension (Paco2) (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). The reduced Pao2 and elevated alveolar-arterial oxygen differences (AaDo2), and dead space (VD)-tidal volume ratios (VD/VT) are indicative of ventilation/blood flow maldistribution (1)(2)(3)(6)(7)(8)(9)(10). Interpretation of previous data on gas exchange and arterial blood gases in scoliosis is difficult because some of the studies have included patients with scoliosis due to different etiologies or coexistent chronic pulmonary disease, some have too few patients for statistical analyses, and in some the severity of scoliosis has not been documented.…”