[Alterations of pulmonary blood perfusion in chronic respiratory insufficiency. Evaluation by normalized carbon monoxide uptake measured at the patient's bedside after intensive care].

: CO uptake (VCO) normalized by CO2 output (VCO2) and by alveolar ventilation (VA) does not depend on lung exchanger activity or on mixing. It reflects circulatory amputation in patients with kyphoscoliosis. Measurements were therefore performed in patients with chronic respiratory failure (CRF) stabilized after intensive care to evaluate the deterioration of blood perfusion. The VCO/VCO2 ratio (specific VCO, VCO Sp) was measured, together with gasometry, at the patient's bedside in 41 cases of CRF (group P). In some cases, measurements were repeated either after modification of FIO2 or of the respiratory rate (bradypnoea), or during the patient's stay in hospital. The results were compared with those obtained in a group of patients with stable emphysema (group E). The VCO Sp and VCO/VA deficit values were extremely variable but always severe, and were higher in the E group. They were little modified when SaO2 was corrected by FIO2 without excess, when forced bradypnoea increased VA and PaO2, or during the months of clinical stabilization which followed the measurements. The authors discuss the significance of the deficit compared with the alterations of spirometry and CO ductance and with bradypnoea-induced improvement of DuCO and PaO2. The results obtained indicate the degree of vascular bed destruction in CRF. They justify a systematic application of the test to determine its value and significance compared with other methods used to explore pulmonary circulation.