**4.1. Modification of Dialysis Techniques and Mineral Abnormalities**

The prevalence of UP declines by using biocompatible dialysis membranes [66]. Hence, the first approach to improve UP is still to optimize the dialysis efficiency, use biocompatible dialysis membranes and improve the nutrition status of patients. One study demonstrates that in a series of 30 cases, a polymethylmethacrylate (PMMA) artificial kidney may be a useful adjuvant therapy in chronic hemodialysis patients with severe UP, as it may eliminate more serum cytokines by adsorption than other types of high-flux membranes [67].

Because divalent ions, including magnesium and calcium, may possibly be involved in the pathogenesis of uremia, using a hemodialysis bath with low calcium and magnesium concen‐ tration [45,68,69] and keeping the calcium × phosphate product less than 55 mg2 /dL2 can play a role in improving the pruritus [35]. However, drastic reduction in dialysate calcium concen‐ tration may possibly aggravate renal osteodystrophy.

#### **4.2. Efficient Dialysis**

It is a common experience that pruritus is more frequent in underdialyzed patients and improves by increasing the efficacy of dialysis. Pruritus patients tend to have higher blood urea nitrogen and lower K*<sup>t</sup>* /V values [70]. Increasing the K*<sup>t</sup>* /V from a mean of 1.05 to 1.24 in severely pruritic patients improved their symptoms significantly [70].

#### **4.3. Parathyroidectomy**

Patients who experience pruritus together with hypercalcemia and hyperparathyroidism should be treated by parathyroidectomy [46,71]. However, there is no relation between parathyroid hormone and UP, parathyroidectomy should not be used as a routine procedure [2]. It was found that patients with hypocalcemia or serum calcium at the normal limit can still experience pruritus. It can be concluded that the relationship between serum calcium level and pruritus is hardly found [72].

#### **4.4. Phototherapy**

The role of phototherapy in renal pruritus has been assessed by double-blind trials. Ultraviolet B (UVB) has been generally, although not uniformly, shown to be therapeutic. The mechanism of the antipruritic effect of UVB is not completely understood. Among the proposed mecha‐ nisms are inactivation of a circulating pruritogenic substance, formation of a photo-product that relieves pruritus, alteration of divalent ion content in the skin, suppression of histamine release as well as deactivation of circulating pruritogenic substances [16] and promotion of cutaneous nerve degeneration [73,74]. UVB phototherapy is well tolerated aside from occa‐ sional instances of sunburn [75]. The duration of the antipruritic effect of thrice-weekly, total body UVB phototherapy (8- 10 sessions in total) is variable but can last for several months. In 1975, Saltzer *et al*. first described successful treatment with irradiation of UVB (wavelength 280- 315 nm), [76] and the results were confirmed by several studies [32,75,77,78]. The study also showed that there was no significant difference between remission rates or length of remission between the intensive, intermediate and prolonged treatment schedule [75,79].

Later, a study by Blachley *et al*. not only showed the efficacy of UVB treatment in 17 patients clinically but also showed, by obtaining skin biopsies before and after therapy, a reduction in skin phosphorus following UVB treatment to values that were comparable with those of patients with nonpruritic uremia or healthy volunteers [77]. Further investigation has been performed using narrowband UVB phototherapy, as most of the data on UV radiation have been predominately derived from studies using broadband UVB [80]. The results showed the effectiveness of narrowband UVB, as 9 of 15 patients with UP were marked as responders; however, remission was not prolonged, as 4 of 6 responders who came back for a follow-up had a recurrence [80,81]. Due to the carcinogenic effect of UVB, ultraviolet A (UVA, wavelength 315- 400 nm), which is safer than UVB, was studied for its efficacy, however, UVA did not demonstrate any benefit [82]. Narrowband UVB, which is generally accepted to be less carcinogenic than broadband UVB, should be a better alternative treatment in both efficacy and safety aspects.

#### **4.5. Acupuncture and Electrical Needle Therapy**

Modern medicine tries to explain the efficacy of acupuncture by describing its effects on the receptors of the nervous system, its action on the endogenous endorphin enkephalin and 5 hydroxytryptamine (5-HT), or that it can increase the number of leukocytes and strengthen the defensive mechanisms of the body [83]. Some studies show the benefit of acupuncture for UP. The fundamental information indicated that pruritus was transmitted by conductive C fibers, and acupuncture generates impulses that are carried by the smaller, myelinated, and rapidly conductive beta and delta fibers, all of which reach the spinal cord. There, opiate-like substances are released that block the slower C fiber impulses [84].

Acupoint injection, at San Yin Jiao (SP6), Xuehai (SP 10), Zusanli (ST 36) and Quchi (LI 11) acupoints, has been reported to be effective in UP [85]. Using a transcutaneous electrical nerve stimulation (TENS) acupressure apparatus at those points also showed a benefit in reducing UP [86]. Duo also reported that an electric needle is effective at two similar points (Quchi and Zusanli) [87]. Che-yi *et al.* also reported that acupuncture at the Quchi (LI 11) acupoint, which is close to the hemodialysis needle puncture site but not too close for acupuncture there to interfere with hemodialysis, is also effective for relieving UP [1]. However, acupuncture does not change the level of biochemical parameters associated with the development of UP including magnesium, iPTH, phosphate and calcium.

#### **4.6. Thermal Therapy**

**4. Physical Treatments**

24 Updates in Hemodialysis

**4.2. Efficient Dialysis**

urea nitrogen and lower K*<sup>t</sup>*

pruritus is hardly found [72].

**4.4. Phototherapy**

**4.3. Parathyroidectomy**

**4.1. Modification of Dialysis Techniques and Mineral Abnormalities**

serum cytokines by adsorption than other types of high-flux membranes [67].

tration [45,68,69] and keeping the calcium × phosphate product less than 55 mg2

tration may possibly aggravate renal osteodystrophy.

The prevalence of UP declines by using biocompatible dialysis membranes [66]. Hence, the first approach to improve UP is still to optimize the dialysis efficiency, use biocompatible dialysis membranes and improve the nutrition status of patients. One study demonstrates that in a series of 30 cases, a polymethylmethacrylate (PMMA) artificial kidney may be a useful adjuvant therapy in chronic hemodialysis patients with severe UP, as it may eliminate more

Because divalent ions, including magnesium and calcium, may possibly be involved in the pathogenesis of uremia, using a hemodialysis bath with low calcium and magnesium concen‐

a role in improving the pruritus [35]. However, drastic reduction in dialysate calcium concen‐

It is a common experience that pruritus is more frequent in underdialyzed patients and improves by increasing the efficacy of dialysis. Pruritus patients tend to have higher blood

Patients who experience pruritus together with hypercalcemia and hyperparathyroidism should be treated by parathyroidectomy [46,71]. However, there is no relation between parathyroid hormone and UP, parathyroidectomy should not be used as a routine procedure [2]. It was found that patients with hypocalcemia or serum calcium at the normal limit can still experience pruritus. It can be concluded that the relationship between serum calcium level and

The role of phototherapy in renal pruritus has been assessed by double-blind trials. Ultraviolet B (UVB) has been generally, although not uniformly, shown to be therapeutic. The mechanism of the antipruritic effect of UVB is not completely understood. Among the proposed mecha‐ nisms are inactivation of a circulating pruritogenic substance, formation of a photo-product that relieves pruritus, alteration of divalent ion content in the skin, suppression of histamine release as well as deactivation of circulating pruritogenic substances [16] and promotion of cutaneous nerve degeneration [73,74]. UVB phototherapy is well tolerated aside from occa‐ sional instances of sunburn [75]. The duration of the antipruritic effect of thrice-weekly, total body UVB phototherapy (8- 10 sessions in total) is variable but can last for several months. In

/V values [70]. Increasing the K*<sup>t</sup>*

severely pruritic patients improved their symptoms significantly [70].

/dL2

/V from a mean of 1.05 to 1.24 in

can play

Hsu *et al*. investigated the effects on UP of 40 degree Celsius thermal therapy with far-infrared rays at the Sanyinjiao acupoint for 15 minutes and found a large decrease in pruritus scores in the thermal therapy group compared with the non-thermal therapy group, even though there was no significant differences between groups [88]. The result implied that thermal therapy may have therapeutic benefits for UP.

#### **4.7. Sauna**

Stimulation of the sweat glands with a sauna has shown benefits, perhaps through augmented excretion of hypothetical pruritogen [89]. However, such treatment may cause major compli‐ cations in fluid balance due to unquantifiable insensible water loss.
