THE CONCEPT OF RAYNAUDS-PHENOMENON OF THE LUNG REVISITED

PURPOSE: Having observed that a cold presser test (CPT) induces a decr ease in carbon monoxide single breath diffusing capacity (DLco) in nor mal subjects contrary to the findings of Fahey et al (Am J Med. 1984;7 6:263-269), we compared the response to CPT for the two types of Rayna ud's phenomenon. PATIENTS: TWO groups of 8 patients suffering from pri mary or secondary Raynaud's phenomenon were examined. METHODS: Single breath diffusing capacity, mean pulmonary artery pressure (PAP), cardi ac output (CO), pulmonary capillary wedge pressure (PwP), and pulmonar y vascular resistance (PVR) were measured before and 30 minutes after CPT, which consisted of immersing both hands in a water bath at 12 deg rees C for 2 minutes. RESULTS: Cold presser testing induced no change in DLco or cardiovascular parameters in patients with secondary Raynau d's phenomenon. Conversely, in patients with the primary form, it indu ced a significant decrease in DLco (16%), PAP (20%), and PVR (27%), wh ereas CO and PwP remained unaltered. CONCLUSIONS: The concept of pulmo nary Raynaud's phenomenon had to be reconsidered, as it is also observ ed in normal subjects, and is due to a vasodilatation and not to a vas oconstriction of the pulmonary artery (Frans et al, J Appl Physiol. 19 94;76:750-755). In patients with primary Raynaud's phenomenon, the dec rease in DLco is not only a physiological response, but a pathological response to a CPT, as it is significantly more marked in patients tha n in control subjects (16% versus 10% for controls, same reference). T he contribution by Fahey et al remains important, however, in that it allows assessing whether a patient with Raynaud's phenomenon suffers f rom the primary or secondary form of the disease. (C) 1996 by Excrpta Medica, Inc.