Pain is a common problem affecting 10–25 % of the general population. Studies suggest that at least 50 % patients with severe CKD (eGFR <30 ml/min) including patients on dialysis experience chronic pain. The high prevalence of pain is concerning because pain adversely affects quality of life.

There are a wide variety of causes of pain in CKD and dialysis patients. Some are specific to kidney patients but most are not. Whatever the cause of pain this is likely to increase in intensity during dialysis. This is at least partly because patients cannot move around to ease their pain, and partly because opioid drugs are cleared from the circulation during dialysis. Pain in dialysis patients can be classified as follows:

First, you should investigate this unless it has already been investigated. For example if a CKD patient complains of back pain, degenerative changes and osteoporotic fractures are more common than myelomatous deposits but all three need to be considered. Next you must appreciate that the answer to pain does not always lie in a bottle of tablets. People’s perception of pain, and learned responses to pain vary enormously. The psyche contributes significantly to the severity of pain and its impact on a patient’s life. At one extreme exists the patient who stubs a toe and attends for a sick line, while at the other extreme there are patients who live with chronic inflammatory or malignant pain, and still continue to hold down jobs. Having said all that, it is likely that most patients with chronic pain will require some form of analgesia.

Yes. In 1986 the WHO established an evidence based three step ladder for mild (1–3/10 pain score), moderate (4–6/10) and severe (>7/10) levels of malignant pain that has since been adapted for other patient groups including CKD and ESRD patients (Fig. 33.1).

At any step in the ladder adjuvant drugs may be added depending on the cause of the pain. These include antidepressants and anticonvulsant drugs for neuropathic pain.

Paracetamol does not accumulate in renal failure but may be nephrotoxic if given at very high doses/in overdose. The dose of paracetamol for predialysis patients is the same as for normal renal function while dialysis patients are safe to receive paracetamol as first line treatment for pain up to a maximum of 1G three times daily

Non steroidal anti-inflammatory drugs increase the risk of GI bleeding in dialysis patients and are also nephrotoxic, as shown in Box 33.2. NSAIDs should probably be avoided in patients with eGFR less than 60 ml/min because of this. They can however be used with caution for short periods if the doctor and patient are prepared to monitor their effects on the kidney closely. It could be argued that once a patient is on dialysis then NSAIDs can be used again on the grounds that they have no more renal function to lose. This is certainly true of the anuric patient, but may not be true for patients with significant residual renal function. Finally, there are no advantages to giving COX-2 inhibitors (such as celecoxib) to renal patients. They are just as nephrotoxic as NSAIDs