Spirometric and broncho-spirometric studies in five-rib thoracoplasties.

It is a well-known fact that thoracoplasty places a severe strain on the patient, affecting in particular the interchange of gases. Stead and Soucheray (1952), of Minneapolis, studied these problems during the first 16 to 20 hours after thoracoplasty operations. It must suffice here to mention some of the principal data in their investigation. They found a substantial increase in the respiratory minute volume, and no less than 58% of that increase was referable to the ventilation of a functionally dead space. The tidal air decreased (a traumatic effect), but it was compensated by an increased frequency of respiration to enable the carbon dioxide to be expired. It is then that the patient needs the respiratory reserve of 70 to 85% which is generally considered to be essential for the operation. If the blood shows a high carbon dioxide content the day after the operation then there is ventilatory insufficiency, and tracheotomy may be a life-saving measure. The operation is followed by a period of recovery during which the pulmonary function steadily improves. Opinions vary as to the duration of this period. Jacobaeus, Frenckner, and Bjorkman (1932) spoke of three years; Birath (1944) demonstrated functional improvement from two to seven months after the operation. More recent investigations at frequent intervals postoperatively by Gaensler (1952) confirm that recovery is substantially complete within two months. It seems advisable, therefore, to keep the patient in hospital for about six to ten weeks after operation for physiotherapy. Notwithstanding every possible measure there still remains a varying degree of functional loss after thoracoplasty. To what, then, is this to be attributed? Attention should be drawn, first and foremost, to investigations by Bjorkman (1934) and Bjorkman and Carlens (1951) and by Pinner and others (1942), whodemonstratedbilateral'yreduced function in spite of unilateral surgery. Those factors, besides collapse of the pulmonary parenchyma