[Assessment of muscular toxicity due to chemotherapy by cardio-pulmonary exercise testing]. / Évaluation de la toxicité musculaire de la chimiothérapie lors d'une épreuve fonctionnelle à l'exercice.

INTRODUCTION: Cardio-pulmonary exercise testing (CPET) is frequently used to assess aerobic capacity, to evaluate respiratory tolerance and to provide prognostic information. Therefore, CPET is often incorporated in the preoperative assessment of cancer patients. This clinical case report presents the preoperative assessment of a patient before thoracic surgery, in whom an important decrease of aerobic capacity was noted, possibly because of muscular toxicity linked to chemotherapy. CASE REPORT: This clinical case concerns a fit, 66-year-old man with a large cell carcinoma of the bronchus. He had received 2 cycles of adjuvant chemotherapy. Subsequently, a left pneumonectomy had been proposed and preoperative assessment performed. CPET showed no further increase in oxygen uptake after the first ventilatory threshold, in spite of increases in carbon dioxide output, minute ventilation and heart rate. Moreover, maximal oxygen uptake was low and there was a decrease of oxygen pulse at maximal effort. CONCLUSION: We suggest that the limitation of effort was due to a limitation of muscular oxygen extraction, which could be explained by possible muscular toxicity due to chemotherapy.

Physiological responses to repeated apneas in underwater hockey players and controls.

The aim of this study was to investigate the effects of short repeated apneas on breathing pattern and circulatory response in trained (underwater hockey players: UHP) and untrained (controls: CTL) subjects. The subjects performed five apneas (A1-A5) while cycling with the face immersed in thermoneutral water. Respiratory parameters were recorded 1 minute before and after each apnea and venous blood samples were collected before each apnea and at 0, 2, 5 and 10 minutes after the last apnea. Arterial saturation (SaO2) and heart rate were continuously recorded during the experiment. Before the repeated apneas, UHP had lower ventilation, higher P(ET)CO2 (p < 0.05) and lower P(ET)O2 than CTL (p < 0.001). After the apneas, the P(ET)O2 values were always lower in UHP (p < 0.001) than CTL but with no difference for averaged P(ET)CO2 (p = 0.32). The apnea response, i.e., bradycardia and increased mean arterial blood pressure, was observed and it remained unchanged throughout the series in the two groups. The SaO, decreased in both groups during each apnea but the post-exercise SaO2 values were higher in UHP after A2 to A5 than in CTL (p < 0.01). The post-apnea lactate concentrations were lower in UHP than in CTL. These results indicate that more pronounced bradycardia could lead to less oxygen desaturation during repeated apneas in UHP. The UHP show a specific hypoventilatory pattern after repeated apneas, as well as a more pronounced cardiovascular response than CTL. They indeed showed no detraining of the diving response.