Hemodialysis delivery, dialysis dose achievement, and vascular access types in hemodialysis patients from the Gulf Cooperation Council countries enrolled in the dialysis outcomes and practice patterns study phase 5 (2012-2015)

Abstract

The prospective observational Dialysis Outcomes and Practice Patterns Study (DOPPS) was initiated in late 2012 in national samples of hemodialysis (HD) units (n = 41 study sites) in all six Gulf Cooperation Council (GCC) countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates). For many years, guidelines have recommended single pool Kt/V ≥1.2 as the minimum adequate dose for chronic HD patients. Here, we report initial DOPPS results regarding HD practices related to dialysis dose achievement in the GCC. A total of 928 adult HD patients were included in this analysis from 41 centers representing all six GCC countries. Baseline descriptive statistics (e.g., mean, standard deviation, median, interquartile range, or percentage) were calculated for the study sample. Results were weighted according to the fraction of HD patients sampled within each participating study site. Mean age varied between 51 years in Bahrain, Oman, and Saudi Arabia, 55 years in the United Arab Emirates (UAE) and Kuwait, and 62 years in Qatar. Mean body mass index (BMI) was the lowest in Oman patients (23.9 kg/m 2 , but the remaining GCC countries had mean BMIs of 25.7-28.9 kg/m 2 and substantial fractions of overweight patients. Median dialysis vintage ranged from 1.52 years in Kuwait to 3.52 years in Oman. Mean treatment time per session varied from 202 min in Saudi Arabia to 230 min in Qatar while mean blood flow rate (BFR) ranged between 267 mL/min in Oman and 310 mL/min in Saudi Arabia. Interdialytic weight gain varied considerably among GCC countries between 3.1 and 4.0 kg. Central venous catheter use was high among GCC countries, ranging from 29% in Oman to 56% in Kuwait, with other countries averaging 30-40% catheter use. Data were available only for 50-76% of patients in four GCC countries (Kuwait, Qatar, Saudi Arabia, and UAE) for calculating single pool Kt/V to indicate dialysis adequacy. When calculated for patients with vintage >1 year and dialyzing three times per week, mean single pool Kt/V was highest in Qatar and the UAE (1.50-1.51), intermediate in Kuwait (1.35), and lowest in Saudi Arabia (1.29). A higher risk of mortality was observed for patients having a single pool Kt/V <1.2 (vs. ≥1.2) [hazard ratio (HR) = 1.71, 95% confidence interval [CI]: 1.01-2.92]. Achievement of Kt/V in the GCC, although lower than in other DOPPS regions such as Europe/ANZ and North America, was similar to that in Japan. Japan and the GCC also share the practice of having a lower blood volume filtered per HD session per kg body weight. These findings suggest that increasing mean BFR and treatment time in the GCC, along with reducing catheter use, would substantially increase overall achievement of Kt/V >1.2 in the GCC, and hence, may improve survival. These mortality findings will need to be confirmed with up-coming GCC-DOPPS 6 analysis.

Hemodialysis biocompatibility mathematical models to predict the inflammatory biomarkers released in dialysis patients based on hemodialysis membrane characteristics and clinical practices

“…Additionally, under flow conditions, the rougher membrane leads to a clear increase in the release of C5b-9 and vWF, which confirms the mechanical hemolysis due to the increased shear stress experienced near the membrane surface 44 .A rougher surface intensifies FB adsorption, which leads to more severe inflammatory response in HD patients 41 , 42 . Importantly, the Qb range investigated is on the lower side of the spectrum of prescribed Qb for Canadian and American patients (mean prescribed Qb of 371.85 and 425.42 mL/min 45 , respectively), so a more pronounced tendency for hemolysis can be expected for those patients, especially when rough membranes are used.…”

Current State of Vascular Access in Patients on Hemodialysis in Bahrain

“…The study results fall in the range of CVC usage in Gulf countries ranging from 29% in Oman to 56% in Kuwait, which is considered high according to the international guidelines. 12 Despite clear international guidelines for timely initiation of a HD via AVF, the rates remain poor. Several factors attribute to this internationally, both remedial and non-remedial.…”

Influence of hemodialysis blood flow rate on the thrombogenic potential in patients with central venous catheters

“…Most dialysis catheters can be capable of achieving flow rates exceeding 300 mL/min, with the intent of producing a more efficient dialysis session. However, recent studies showed that countries that had high success in hemodialysis had a much lower average blood flow rate (200mL/min) (Pisoni et al , Alyousef et al 2016. In Europe and in Saudi Arabia, for example, a blood flow rate lower than 300 mL/min is frequently used in dialysis treatment, once the adequate hemodialysis depends on certain factors that include duration and frequency of dialysis sessions, dialyzer size, dialysate characteristics, blood flow rate, vascular access, protein intake, physical activity, and hematocrit (Alyousef et al 2016).…”

“…Therefore, flow rate values within the CVC may vary during the hemodialysis sessions and the professionals do not take into account the difference in flow rate values and the increased possibility of thrombus formation. Early identification of the presence of the thrombus by means of flow rate variation may contribute to reduce morbidity and to the maintenance of venous access, especially for End Stage Renal Disease (ESRD) patients with limited vascular access (Alyousef et al 2016). Figure 4 and Table I show that by the power regression model the exponent presented small variations when compared to the different catheter sizes.…”