SHORT-TERM EFFECT OF COLD PROVOCATION ON SINGLE-BREATH CARBON-MONOXIDE DIFFUSING-CAPACITY IN SUBJECTS WITH AND WITHOUT RAYNAUDS-PHENOMENON

The lung diffusing capacity for carbon monoxide was determined by the single breath method (DLCO(sb)) before, during, and after immersion of the left hand in cold water in four groups of subjects: (i) normal in dividuals; (ii) subjects with idiopathic Raynaud's disease; (iii) pati ents with progressive systemic sclerosis without associated Raynaud's phenomenon; and(iv)patients with connective tissue disease associated with Raynaud's phenomenon. Our results showed significant differences in the evolution of DLCO(sb) after cold stimulation between the groups . Control subjects (group one) showed a transient but significant redu ction in DLCO(sb) at the end of two minutes of cold stimulation normal izing ten minutes later. Subjects with primary Raynaud's phenomenon (g roup two) showed on the contrary a transient but significant rise in D LCO(sb) after 2 minutes, while subjects with an isolated connective ti ssue disease without Raynaud's phenomenon (group three) showed a signi ficant decrease in DLCO(sb) at both observation times. Patients with R aynaud's phenomenon associated with a connective tissue disease (group four) showed a delayed decrease in DLCO(sb) ten minutes after cold st imulation. This latter result appeared as an addition to the effects o f cold stimulation observed in groups two and three.