The role of autonomic neuropathy in the genesis of intradialytic hypotension

Background: Intradialytic hypotension is a frequent complication of hemodialysis. Some authors have pointed to autonomic neuropathy as a major cause of intradialytic hypotension. However, other authors have found no such association. Methods: Tilt-table test and time-domain measures of heart rate variation were used to determine autonomic function. Conventional nerve conduction studies (NCS) were also performed to assess whether intradialytic hypotension is associated with polyneuropathy and autonomic neuropathy. Results: The indidences of polyneuropathy confirmed by standard NCS were similar for the intradialytic hypotensive and normotensive subjects, implying that polyneuropathy is not strongly related to intradialytic hypotension. However, heart rate variation decreased significantly in intradialytic hypotensive subjects, suggesting that isolated autonomic neuropathy plays a major role in the pathogenesis of intradialytic hypotension. One of 9 intradialytic hypotensive subjects had normal autonomic tests and 2 of 18 normotensive subjects had abnormal autonomic function, implying that intradialytic hypotension is not caused by autonomic neuropathy alone. Conclusion: Autonomic neuropathy plays an important role in the genesis of intradialytic neuropathy. Tilt-table is easily performed and time-domain measures for heart rate variation are easily determined. Tilt-table test and time-domain measures provide useful information concerning autonomic function. Copyright (C) 2001 S. Karger AG, Basel.