Etiopathogenesis of chronic kidney disease-associated pruritus: putting the pieces of the puzzle together.

Defined as the unpleasant sensation that causes the desire to scratch, pruritus is the most common skin symptom associated with uremia and appears in almost half of patients with advanced chronic kidney disease (CKD). Beyond its direct impact on quality of life, CKD-associated pruritus (CKD-aP) is an independent predictor of mortality that also has a synergistic effect with other quality of life-related symptoms, such as insomnia, depression, and anxiety. Although different mechanisms have been proposed to explain the origin of Pa-ERC, its etiopathogenesis is still not fully understood. Since new therapeutic targets have been identified and several clinical trials have recently shown promising results, our current understanding of the interrelationships has expanded significantly and the pathophysiological mechanisms underlying CKD-aP are now considered to be multifactorial. The potential triggers of pruritus in patients with CKD are discussed in this review, including hypotheses about skin xerosis, accumulation of uremic toxins, dysregulation of the immune system and systemic inflammation, uremic neuropathy, and imbalances in the endogenous opioid system. Other non-uremic causes of pruritus are also discussed, with the aim of guiding the physicians to apply an adequate aetiopathogenic approach to CKD-aP in their day-to-day clinical practice.

Efficacy of neuromuscular electrostimulation intervention to improve physical function in haemodialysis patients.

BACKGROUND: Haemodialysis (HD) patients are characterised by muscle wasting, decreased physical function and poor quality of life. The objective was to analyse the effect of an intradialysis NMES training programme in muscular strength, functional capacity and quality of life in our HD patients. MATERIAL: HD patients were assigned to NMES (ESG) or control group (CG) in a 12-week single-centre prospective study. Transversal quadriceps muscular area, maximum length quadriceps strength (MLQS), handgrip, sit-to-stand-to-sit 10 test (STS10), "6-min walking test" (6MWT); EuroQol-5D health-related quality of life (EQ-5D) questionnaire, subjective global assessment (SGA) and NMES symptoms questionnaires (SQ) were completed. RESULTS: Thirty-eight patients (54 % men). Mean age 69.7 years. 32.1 months on HD, 23 ESG and 15 in CG. In contrast with CG, ESG significantly (*p < 0.05) improved MLQS* (10.2 6.7 vs. 13.1 8.1 kg), STS10* (41 18.7 vs. 37.2 23.9 s), 6MWT* (12 %, 280.5 vs. 312.4 m) and EQ-5D score* (52.7 vs. 65.5) at the end of the study. However, lower SQ score* (8.5 vs. 5.8 sympt./patient) in ESG was observed, mainly due to muscular pain* (2.2 vs. 1.2), cramps* (1.6 vs. 1.2), numbness* (1.7 vs. 1.1) or stinging* (1.5 vs. 1.1). In ESG, 44 and 72 % referred better wellness sensation and physical condition in SGA, respectively. CONCLUSIONS: Intradialytic NMES of both quadriceps improved muscular strength, functional capacity and quality of life in our HD patients. With the obtained results, NMES constitutes a novel therapeutic alternative to improve the deteriorated physical condition and quality of life of these patients.