TY - JOUR
T1 - Response to head-up tilt in cramping and noncramping hemodialysis patients
AU - Kaplan, B.
AU - Wang, T.
AU - Rammohan, M.
AU - Del Greco, F.
AU - Molteni, A.
AU - Atkinson, A. J.
PY - 1992
Y1 - 1992
N2 - Hemodialysis-associated skeletal muscle cramps are generally ascribed to a reduction in plasma volume, but during this procedure, it is not known how volume contraction results in cramps. To elucidate this mechanism, we compared responses to one hour of 60° head-up tilt in 8 patients who cramped during no more than one-sixth of their dialyses and in 8 patients who cramped at least half the time. Age and recumbent blood pressure were similar in each group, but more patients with frequent cramps had diabetes underlying their renal failure (p = 0.013) and had been dialyzed for less than 3 years (p = 0.020). Baseline plasma renin activity and plasma norepinephrine and arginine vasopressin concentrations were similar in both groups, except plasma renin activity in one patient with frequent cramps, which was 15 times higher than in the other patients. After tilting, systolic blood pressure fell an average of 17% in patients who cramped infrequently (p = 0.0031) but only 10% in frequently cramping patients. The ratio of tilt/recumbent norepinephrine levels exceeded 1.5 in 7 patients with frequent cramps but was less than this in 6 patients who cramped infrequently (p = 0.020). One of the 2 infrequently cramping patients with a ratio above 1.5 was the only individual to have a normal renin response to tilt. We propose that cramps are prone to occur during hemodialysis in patients whose sympathetic nervous system response to volume stress is partially intact but is not modulated by concurrent activation of the renin-angiotensin system.
AB - Hemodialysis-associated skeletal muscle cramps are generally ascribed to a reduction in plasma volume, but during this procedure, it is not known how volume contraction results in cramps. To elucidate this mechanism, we compared responses to one hour of 60° head-up tilt in 8 patients who cramped during no more than one-sixth of their dialyses and in 8 patients who cramped at least half the time. Age and recumbent blood pressure were similar in each group, but more patients with frequent cramps had diabetes underlying their renal failure (p = 0.013) and had been dialyzed for less than 3 years (p = 0.020). Baseline plasma renin activity and plasma norepinephrine and arginine vasopressin concentrations were similar in both groups, except plasma renin activity in one patient with frequent cramps, which was 15 times higher than in the other patients. After tilting, systolic blood pressure fell an average of 17% in patients who cramped infrequently (p = 0.0031) but only 10% in frequently cramping patients. The ratio of tilt/recumbent norepinephrine levels exceeded 1.5 in 7 patients with frequent cramps but was less than this in 6 patients who cramped infrequently (p = 0.020). One of the 2 infrequently cramping patients with a ratio above 1.5 was the only individual to have a normal renin response to tilt. We propose that cramps are prone to occur during hemodialysis in patients whose sympathetic nervous system response to volume stress is partially intact but is not modulated by concurrent activation of the renin-angiotensin system.
UR - http://www.scopus.com/inward/record.url?scp=0026505013&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026505013&partnerID=8YFLogxK
M3 - Article
C2 - 1592545
AN - SCOPUS:0026505013
SN - 0174-4879
VL - 30
SP - 173
EP - 180
JO - International Journal of Clinical Pharmacology Therapy and Toxicology
JF - International Journal of Clinical Pharmacology Therapy and Toxicology
IS - 5
ER -