Pain is a common complication during hemaodialysis. It may be related to the procedure itself such as in the case of large fluid shifts that may result in cramping or simply the discomfort of remaining seated for 4 hours. Patients frequently complain of back pain or leg pain however some pain is non specific and may even defy diagnosis. The prevalence of pain among patients on hemodialysis has been reported to be as high as 47%. Unfortunately despite such a high reported prevalence there are no guidelines for the treatment of pain in patients on dialysis.
A study of 100 dialysis patients reported in the clinical journal of the american society of nephrology found that up to 51% of patients experienced chronic pain on hemodialysis. Pain derived from muscle and bone was the most prominent reported cause of pain. Headache was also very common and usually restricted to the dialysis sessions. However some patients did develop chronic headache as well. While patients with diabetic nerve damage of any kind were more likely to have pain on haemodialysis.
Patients with diabetes and chronic pain were most likely to have low vitamin d levels as well as low levels of parathyroid hormone (PTH). This correlation may imply that PTH and Vitamin D may play some role in the pathology of pain in these patients. This was further corroborated by the fact that calcium, which is closely regulated by both vitamin D and PTH, was an independent risk factor for chronic pain. Higher calcium levels were very significant for greater degrees of pain along with higher levels of PTH even if within the range considered normal for haemodialysis patients.
The correlation between pain and mineral metabolism of calcium is very interesting as PTH vitamin D and calcium are very closely related in the maintenance of good bone health on dialysis. It is already well known that disturbances of this important axis of hormones may lead to severe bone disease. However a new role in chronic pain for these markers may need to be explored by further studies.
