Showing papers on "Hypoventilation published in 1973"

Effects of tracheostomy in two cases of hypersomnia with periodic breathing.

Abstract: Two non-obese patients suffering from hypersomnia with periodic breathing, who presented predominantly obstructive apnoea persisting throughout sleep, underwent tracheotomy with placement of a permanent tracheal cannula. Before tracheostomy there was a serious state of alveolar hypoventilation with a marked rise in pulmonary arterial pressure which appeared during sleep. After tracheostomy breathing during sleep became regular, pulmonary arterial pressure became normal, and daytime drowsiness disappeared. These observations suggest that the obstruction of the upper air tracts during sleep represents the most important factor in the pathogenesis of hypersomnia with periodic breathing.

Hypoxia and hypercapnia caused by respiratory compensation for metabolic alkalosis.

Abstract: Two patients with metabolic alkalosis manifested compensatory hypoventilation severe enough to cause hypoxia and hypercapnia. These changes could not be attributed to a coexisting, independent pulmonary problem; evidence for pulmonary disease was not found, and blood gas values gradually returned toward normal with correction of the alkalosis. Available data are too limited to define 95 per cent confidence limits for the respiratory response to metabolic alkalosis of the severity observed; however, when previously established limits for less severe alkalosis were extrapolated upward, they included the blood gas values obtained in these patients and similar ones reported by others. This study indicates that metabolic alkalosis in patients without pulmonary disease can cause compensatory hypoventilation, hypercapnia, and hypoxia. The magnitude of change in blood carbon dioxide and oxygen tensions is directly proportional to the serum bicarbonate concentration.

Acid-base response to acute carbon dioxide changes in chronic obstructive pulmonary disease.

Abstract: The influence of the chronic arterial carbon dioxide tension on the acid-base response to acute change in arterial carbon dioxide tension was studied in patients with chronic obstructive pulmonary disease. Acute changes in arterial carbon dioxide tension were produced experimentally by having the patients breathe various mixtures of carbon dioxide in air and by hyperventilation. Acute changes in arterial carbon dioxide tension occurred clinically during oxygen-induced hypoventilation, followed by ventilator therapy. The acute acid-base response was expressed as the ratio of change in arterial hydrogen ion concentration to change in arterial carbon dioxide tension. This ratio was inversely and linearly related to chronic values of arterial carbon dioxide tension and plasma bicarbonate concentration. The more efficient buffering of acute changes in carbon dioxide tension in patients with chronic obstructive pulmonary disease with hypercapnia was attributed both to high chronic bicarbonate concentrations and...

Postoperative ventilatory failure in a patient with primary alveolar hypoventilation

Abstract: SUMMARY slightly obese woman developed severe ventilatory failure which required assisted ventilation on the first day after an emergency appendicectomy. Subsequent investigation revealed a mild restrictive ventilatory defect, hypoxaemia and hypercapnia and an abnormal ventilatory response to carbon dioxide. The patient was considered to have primary alveolar hypoventilation and, because of this, was abnormally sensitive to narcotic analgesics.