IMPAIRED VENTILATORY RESPONSE TO CARBON-DIOXIDE IN PATIENTS WITH CHRONIC-RENAL-FAILURE - IMPLICATIONS FOR THE INTENSIVE-CARE UNIT

Objectives: To compare aspects of ventilatory control and the susceptibility to depressant drugs between patients with chronic renal failure and normal volunteers. Design: Prospective, controlled study. Setting: Pulmonary function laboratory of a university hospital. Patients: Six patients with chronic renal failure requiring hemodialysis and ten normal, control subjects. Interventions: Ventilatory responses to breathing CO2 were studied using a rebreathing method The effects of triazolam (0.5 mg orally) and meperidine (1 mg/kg, subcutaneously) on these measurements were also studied. Measurements and Main Results: Dialysis patients showed definite impairment in the ventilatory response to CO2, which could not be accounted for by differences in respiratory mechanics, muscle strength, or acid-base status. Meperidine impaired ventilatory responses in control subjects and in renal patients, while triazolam had little effect on either group. The effect of the drugs was not proportionately greater in dialysis patients than in control subjects. Conclusions: Chronic renal failure results in a poorly responsive ventilatory control system, which may make renal failure patients more difficult to wean from mechanical ventilation. Theoretically, these patients may be more vulnerable to disturbances in blood gas homeostasis and subsequent respiratory arrest than other patients in an unmonitored environment.