Lower prevalence of chronic itch in haemodialysis patients on loop diuretics: results from GEHIS (German Epidemiological Hemodialysis Itch Study)

Depolarization of mouse DRG neurons by GABA does not translate into acute pain or hyperalgesia in healthy human volunteers

The majority of somatosensory DRG neurons express GABAA receptors (GABAAR) and depolarise in response to its activation based on the high intracellular chloride concentration maintained by the Na-K-Cl cotransporter type 1 (NKCC1). The translation of this response to peripheral nerve terminals in people is so far unclear. We show here that GABA (EC50 = 16.67μM) acting via GABAAR produces an influx of extracellular calcium in approximately 20% (336/1720) of isolated mouse DRG neurons. In contrast, upon injection into forearm skin of healthy volunteers GABA (1mM, 100μl) did not induce any overt sensations nor a specific flare response and did not sensitize C-nociceptors to slow depolarizing electrical sinusoidal stimuli. Block of the inward chloride transporter NKCC1 by furosemide (1mg/100μl) did not reduce electrically evoked pain ratings nor did repetitive GABA stimulation in combination with an inhibited NKCC1 driven chloride replenishment by furosemide. Finally, we generated a sustained period of C-fiber firing by iontophoretically delivering codeine or histamine to induce tonic itch. Neither the intensity nor the duration of histamine or codeine itch was affected by prior injection of furosemide. We conclude that although GABA can evoke calcium transients in a proportion of isolated mouse DRG neurons, it does not induce or modify pain or itch ratings in healthy human skin even when chloride gradients are altered by inhibition of the sodium coupled NKCC1 transporter.

Skin Lesions, Skin Care, and Characteristics of Pruritus in Patients Undergoing Haemodialysis

INTRODUCTION

Pruritus has been shown to be a common and burdensome complaint in the general population. In some diseases, there is an even higher rate and intensity of pruritus such as in chronic kidney diseases. In particular, patients requiring dialysis commonly suffer from pruritus with proportions between 22.0 and 90.0%. Few data on the characteristics and burden of such pruritus have been published. Therefore, the aim of this study was to investigate the extent and profiles of pruritus in such patients related to skin lesions and care.

METHODS

A non-interventional cross-sectional study in 14 centres for haemodialysis across Germany was conducted. The survey explored the prevalence, severity, and resulting burden of pruritus and skin lesions.

RESULTS

In total, 302 patients with uraemia (56.5% male, mean age 66.0 ± 14.4 years, mean duration of dialysis 3.9 ± 4.8 years) were included. Skin lesions appeared since start of dialysis in 50.0% of patients, with xerosis (94.7%) and desquamation (25.8%) being the most frequent and disturbing findings. Pruritus was reported by 60.9% of patients undergoing dialysis with a current mean numerical rating scale of 5.1 ± 2.4 occurring most frequently in the back, legs, and arms. About 89.0% of patients with xerosis and 69.0% with desquamation reported self-medication. However, only 40.0% and 28.0% sought medical help, respectively, indicating a remarkable lack of healthcare.

DISCUSSION

The current data suggest a more intensive focus on the skin symptoms and signs related to uraemia in the patients with dialysis and thus underline claims from a previous German large-scale study. Recommendations for early treatment and prevention of skin lesions in dialysis patients should be developed. Further research should be conducted focusing on recognizing subgroups of patients of particular vulnerability to pruritus and skin lesions, which may facilitate identifying patients at risk in an early moment. Moreover, a more specific tool for screening of skin lesions as well as pruritus may be useful since the existing instruments lack such specificity.

Chronic Kidney Disease-Associated Itch (CKD-aI) in Children-A Narrative Review

Chronic kidney disease (CKD) is a condition of widespread epidemiology and serious consequences affecting all organs of the organism and associated with significant mortality. The knowledge on CKD is rapidly evolving, especially concerning adults. Recently, more data is also appearing regarding CKD in children. Chronic itch (CI) is a common symptom appearing due to various underlying dermatological and systemic conditions. CI may also appear in association with CKD and is termed chronic kidney disease-associated itch (CKD-aI). CKD-aI is relatively well-described in the literature concerning adults, yet it also affects children. Unfortunately, the data on paediatric CKD-aI is particularly scarce. This narrative review aims to describe various aspects of CKD-aI with an emphasis on children, based on the available data in this population and the data extrapolated from adults. Its pathogenesis is described in details, focusing on the growing role of uraemic toxins (UTs), as well as immune dysfunction, altered opioid transmission, infectious agents, xerosis, neuropathy and dialysis-associated aspects. Moreover, epidemiological and clinical aspects are reviewed based on the few data on CKD-aI in children, whereas treatment recommendations are proposed as well, based on the literature on CKD-aI in adults and own experience in managing CI in children.

Comparison of gabapentin and doxepin in the management of uremic pruritus: A randomized crossover clinical trial

Gabapentin and doxepin are well-known treatments of uremic pruritus in hemodialysis patients but no head-to-head studies were conducted to date. The aim of this trial is to compare the efficacy and the tolerability of gabapentin and doxepin in the treatment of uremic pruritus in hemodialysis patients. A single-blind crossover randomized trial was conducted that included hemodialysis patients with uremic pruritus. Patients were randomized to receive 10 mg doxepin daily or 100 mg gabapentin for 4 weeks and the two groups were treated conversely for another 4 weeks after a 4-week washout period. Eighty-five patients were screened for eligibility. Thirty-one met the inclusion criteria and four were excluded. Sixteen patients agreed and signed the consent and two withdrew from the study. VAS scores at baseline were 6.71 and 6.14, and dropped to 0.57 and 2.35 at week 4 in the gabapentin and doxepin groups, respectively. Mean scores of the 5-Domain Itch Scale (5-D) at baseline were 14.71 and 14.64, and dropped to 5.78 and 7.57 at week 4 in the gabapentin and doxepin groups, respectively. Mean scores of the Dermatology Life Quality Index (DLQI) at baseline were 9.6429 and 8.7857, and dropped to 0.71 and 3.35 at week 4 in the gabapentin and doxepin groups, respectively. Reductions in Visual Analog Scale (VAS), 5-D and DLQI were statistically significant (P < .05). No serious side effects were recorded. Limitations of this study include single-blind design, small number of included cases and lack of placebo control. Gabapentin was more effective than doxepin in decreasing uremic pruritus severity and improving quality of life of these patients.

An update review of intradialytic hypotension: concept, risk factors, clinical implications and management

Intradialytic hypotension (IDH) is a frequent and serious complication of chronic haemodialysis, linked to adverse long-term outcomes including increased cardiovascular and all-cause mortality. IDH is the end result of the interaction between ultrafiltration rate (UFR), cardiac output and arteriolar tone. Thus excessive ultrafiltration may decrease the cardiac output, especially when compensatory mechanisms (heart rate, myocardial contractility, vascular tone and splanchnic flow shifts) fail to be optimally recruited. The repeated disruption of end-organ perfusion in IDH may lead to various adverse clinical outcomes affecting the heart, central nervous system, kidney and gastrointestinal system. Potential interventions to decrease the incidence or severity of IDH include optimization of the dialysis prescription (cool dialysate, UFR, sodium profiling and high-flux haemofiltration), interventions during the dialysis session (midodrine, mannitol, food intake, intradialytic exercise and intermittent pneumatic compression of the lower limbs) and interventions in the interdialysis period (lower interdialytic weight gain and blood pressure–lowering drugs). However, the evidence base for many of these interventions is thin and optimal prevention and management of IDH awaits further clinical investigation. Developing a consensus definition of IDH will facilitate clinical research. We review the most recent findings on risk factors, pathophysiology and management of IDH and, based on this, we call for a new consensus definition of IDH based on clinical outcomes and define a roadmap for IDH research.

Presence and characteristics of senile pruritus among Danish elderly living in nursing homes

Aim:

To explore the pattern of occurrence and characteristics of senile pruritus among elderly living in nursing homes in the Northern region of Denmark.

Materials & methods:

A Danish questionnaire was developed and distributed to six nursing homes from which 46 residents participated.

Results:

The prevalence of chronic itch was 28.9%. Evening–night and autumn–winter with an average daily itch of 30 min were reported. Itch interfered with night sleep and daily activities. Scratching was common with 61.5% accompanying scratch marks. Half of participants reported Xerosis. Cream, cold compress and cold shower were found to be the most effective remedies for itch relief.

Conclusion:

The present study revealed a high prevalence of chronic pruritus including cases of senile pruritus that needs further exploration for treatment or preventive strategies.

Senile pruritus is chronic itch of unknown origin among the elderly. The occurrence and characteristics among Danish nursing home residents was not known. We developed a Danish questionnaire and distributed it to 6 nursing homes, where 46 residents participated. We found a high prevalence of chronic itch (28.9%). Disturbing itch was reported in evening–night and autumn–winter. Itch interfered with night sleep and daily activities. Scratching was common with scratch marks. Showering precipitated itch, while cold shower was a reliever. Further studies are required to enhance the knowledge about senile pruritus and prevention or treatment strategies for elderly living in nursing homes.

The course of chronic itch in hemodialysis patients: results of a 4-year follow-up study of GEHIS (German Epidemiological Hemodialysis Itch Study)

BACKGROUND

Chronic itch (CI) is a frequent symptom in hemodialysis (HD) patients. Previous studies demonstrated great impairments of general well-being and health-related quality of life (HRQOL) as well as a higher mortality in those suffering from CI.

OBJECTIVE

The German Epidemiological Hemodialysis Itch Study (GEHIS) is a representative cohort of HD patients in Germany. All patients were followed up 4 years later. The current analyses present data on the course of CI in HD patients, its associated factors including comorbidities, laboratory values and HRQOL.

METHODS

We assessed sociodemographic data, routine laboratory values, comorbidities, HRQOL (SF-12), depression and anxiety (HADS), sleep (duration and quality) and in those suffering from CI characteristics, intensity of CI and itch-related quality of life (ItchyQoL). Those with CI were offered a dermatological examination and CI was classified according to the IFSI classification. Patients were asked if they had consulted a physician about CI.

RESULTS

Of the patients who had suffered from CI in 2013 (n = 234), 90.5% (212) patients could be followed up. About 36.3% (n = 85) had died, 9.8% (n = 23) had received a kidney transplant in the meantime. A total of 52 HD patients still suffered from CI, in 52 CI had stopped. Those patients still suffering from CI (n = 52) reported a higher mean itch intensity, lower ItchyQoL, higher levels of anxiety and a lower mean sleeping time in 2013. On the other hand, those who did not suffer from CI anymore showed a significant increase of HRQOL compared to 2013. There was no significant difference in dialysis characteristics and laboratory values except for albumin. Only a minority of patients in HD had consulted a dermatologist because of CI (29.9%).

CONCLUSION

Our data demonstrate that CI is a persisting symptom in 50% of the HD patients and when it disappears HRQOL recovers. We confirm that CI is a disregarded symptom in HD patients.