The role of autonomic neuropathy in the genesis of intradialytic hypotension

Background: Intradialytic hypotension is a frequent complication of hemodia lysis. Some authors have pointed to autonomic neuropathy as a major cause o f intradialytic hypotension. However, other authors have found no such asso ciation. Methods: Tilt-table test and time-domain measures of heart rate va riation were used to determine autonomic function. Conventional nerve condu ction studies (NCS) were also performed to assess whether intradialytic hyp otension is associated with polyneuropathy and autonomic neuropathy. Result s: 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. Howeve r, heart rate variation decreased significantly in intradialytic hypotensiv e subjects, suggesting that isolated autonomic neuropathy plays a major rol e in the pathogenesis of intradialytic hypotension. One of 9 intradialytic hypotensive subjects had normal autonomic tests and 2 of 18 normotensive su bjects had abnormal autonomic function, implying that intradialytic hypoten sion is not caused by autonomic neuropathy alone. Conclusion: Autonomic neu ropathy plays an important role in the genesis of intradialytic neuropathy. Tilt-table is easily performed and time-domain measures for heart rate var iation are easily determined. Tilt-table test and time-domain measures prov ide useful information concerning autonomic function. Copyright (C) 2001 S. Karger AG, Basel.