SUMMARY

This study aimed to evaluate the effectiveness of hemodialysis using single-use dialyzers in patients undergoing maintenance hemodialysis at the Nephro - Urology Department, Hanoi Medical University Hospital, in 2025. A cross-sectional descriptive study was conducted on 100 hemodialysis sessions from April to September 2025. Collected variables included age, sex, body mass index (BMI), dialysis duration, type of vascular access, pre- and post-dialysis blood urea and creatinine concentrations, Kt/V index, and dialysis-related complications. The mean age of participants was 55.2 ± 14.7 years, mean BMI was 21.4 ± 2.6 kg/m², and mean dialysis duration was 211.8 ± 41.5 minutes. Mean urea concentration decreased significantly from 27.7 ± 9.5 mmol/L to 16.0 ± 5.8 mmol/L, and mean creatinine concentration decreased from 712.3 ± 225.6 µmol/L to 474.4 ± 166.9 µmol/L (p < 0.01). The mean Kt/V value was 1.33 ± 0.32, with 69% of dialysis sessions meeting the KDOQI adequacy standard (Kt/V ≥ 1.2). Factors significantly associated with dialysis adequacy included sex, dialysis duration, BMI, and vascular access type (p < 0.05). The overall complication rate was 33%, predominantly hypertension (19%) and hypotension (12%). Hemodialysis using single-use dialyzers demonstrated satisfactory dialysis adequacy and contributed to improving treatment quality for patients undergoing maintenance hemodialysis.

Keywords: Efficacy, Hemodialysis, Single-use dialyzer.

1. INTRODUCTION

End-stage chronic kidney disease is one of the major challenges of global healthcare, with steadily increasing incidence and mortality rates. Maintenance hemodialysis is currently the most common form of renal replacement therapy, helping to prolong survival and improve patients’ quality of life; however, treatment effectiveness largely depends on dialysis technique, equipment, dialysis duration, and particularly the type of dialyzer used.

Dialysis adequacy is commonly evaluated using the Kt/V index. According to the KDOQI guidelines, a Kt/V value ≥ 1.2 is considered adequate.¹ In Vietnam, studies conducted at Cho Ray Hospital, Nghe An Friendship General Hospital, and People’s Hospital 115 have demonstrated a close association between Kt/V and treatment effectiveness, as well as technical factors such as dialyzer type, dialysis duration, and blood flow rate.²^-⁴ Similarly, recent international studies have confirmed that Kt/V is a central measure in assessing dialysis adequacy and has a significant impact on patients’ clinical outcomes.⁵^, ⁶

In the current context, the use of single-use dialyzers is increasingly encouraged to reduce the risk of cross-infection, enhance dialysis efficiency, and ensure patient safety. However, in Vietnam, data on the effectiveness of hemodialysis using single-use dialyzers remain limited. Based on this practical need, we conducted the study entitled “Evaluation of the effectiveness of hemodialysis using single-use dialyzers through the Kt/V index at the Nephro-Urology Department in 2025”, with the aim of assessing dialysis adequacy in patients undergoing hemodialysis with single-use dialyzers.

2. MATERIALS AND METHODS
   1. Study period and setting

The study was conducted from April to September 2025 at the Nephro - Urology Department, Hanoi Medical University Hospital.

1. 2. Study population

- Inclusion criteria:

+ Patients aged ≥ 18 years with chronic kidney disease undergoing hemodialysis (including both maintenance and emergency hemodialysis);

+ Patients whose medical records contained complete information required for the study (demographic data, clinical and laboratory results, etc.).

- Exclusion criteria:

+ Medical records lacking sufficient data for research purposes;

+ Patients who did not consent to participate in the study.

• 3. Methods
• Study design: Cross-sectional descriptive study.
• Sample size: A total of 100 hemodialysis sessions using single-use dialyzers.
• Sampling method: All medical records of patients meeting the inclusion criteria within the study period were included.
• Study variables: Age, sex, body mass index (BMI), duration of the dialysis session, type of vascular access, serum urea and creatinine levels before and after hemodialysis, dialysis adequacy (Kt/V ≥ 1.2), and the incidence of complications.
  The criteria for defining complications were as follows:

+ Hypertension: An increase in mean blood pressure ≥ 15 mmHg.⁷

+ Hypotension: A decrease in systolic blood pressure ≥ 20 mmHg.⁷

+ Dialyzer clotted: The presence of blood clots adhering to the dialyzer membrane.

+ Dialyzer rupture: Reddish discoloration of the dialysate or visible blood leakage from connectors or the dialyzer.

+ Muscle cramps: Sudden onset of painful muscle contractions, muscle stiffness, and difficulty in movement.

+ Nausea and vomiting: Patients experience gastric discomfort, loss of appetite, and vomiting of food or liquids.

+ Kt/V: Data were collected directly from the Nipro Surdial 55 Plus hemodialysis machine.

• Data analysis:

+ Data were entered and analyzed using SPSS software version 20.0;

+ Continuous variables were presented as mean ± standard deviation (mean ± SD), while categorical variables were described using frequencies and percentages;

+ A p-value < 0.05 was considered statistically significant.

• Data collection tools and procedures:

+ Data collection tool: A data collection form designed based on the study variables, including information extracted from medical records such as age, sex, BMI, dialysis duration, type of vascular access, serum urea and creatinine levels pre- post hemodialysis, dialysis adequacy, and complications occurring during hemodialysis.

+ Data collection procedure: Data were extracted from medical records archived at the Nephro- Urology Department, Hanoi Medical University Hospital. To minimize bias, study variables were clearly defined and standardized, and information on patients’ general characteristics was cross-checked using the hospital management software in cases of inconsistency.

1. 4.  Ethical considerations

The study was approved by the leadership of the Nephro - Urology Department. All personal information of participating patients was kept strictly confidential, ensuring data anonymity. Patients were fully informed about the study objectives, procedures, potential benefits, and possible risks, and were entitled to refuse participation or withdraw from the study at any time without affecting their medical care.

3. RESULTS

Table 1. General characteristics of the study population (n = 100)

The mean age of the study participants was 55.2 ± 14.7 years. The mean body mass index (BMI) was 21.4 ± 2.6. The average duration of hemodialysis was 211.8 minutes. The gender distribution was relatively balanced. Catheters were the predominant type of vascular access, accounting for 76% of cases.

Table 2. Changes in serum urea and creatinine levels before and after hemodialysis

The mean serum urea concentration significantly decreased from 27.7 ± 9.5 mmol/L before dialysis to 16.0 ± 5.8 mmol/L after dialysis (p < 0.05). Similarly, the mean serum creatinine level significantly declined from 712.3 ± 225.6 before dialysis to 474.4 ± 166.9 after dialysis (p < 0.05).

Figure 1. Proportion of hemodialysis sessions achieving target Kt/V

The mean Kt/V was 1.33 ± 0.32, with 69% of cases achieving the KDOQI-recommended target (Kt/V ≥ 1.2).

Table 3. Intra-dialytic complications

Note: Each patient may experience more than one complication.

Hypertension and hypotension were the most frequently observed complications, with incidence rates of 19% and 12%, respectively.

Table 4. Relationship between selected factors and Kt/V

*Mann-Whitney Test                          **Kruskal-Wallis Test

The differences in mean Kt/V according to four factors—sex, dialysis duration, BMI, and type of vascular access—were statistically significant (p < 0.05).

4. DISCUSSION

In this study, the mean age of the patients was 55.2 ± 14.7 years. In several studies conducted in Vietnam, the average age of study participants ranged from 44 to 50 years, which is considerably lower than that observed in our study.^{2- 4} However, international studies have reported that the highest prevalence of end-stage chronic kidney disease occurs in the 60–70 age group.^{5, 6} The age distribution in our study is consistent with the characteristics of patients with end-stage renal disease in Vietnam, where the majority of individuals undergoing hemodialysis are middle-aged to elderly. In our study, the proportions of male and female patients were 51% and 49%, respectively. Both domestic and international studies have consistently reported a higher prevalence of male patients compared with female patients.^{2, 5, 6} The mean BMI was 21.4 ± 2.6 kg/m², which is comparable to the findings reported by Pham Van Hien (21,2 kg/m²).² When compared with the studies by Xu and Jeon, the mean BMI in our study was slightly lower.^5,6 This finding reflects a relatively stable nutritional status among patients undergoing hemodialysis. However, approximately 15% of patients had a BMI below 18.5 kg/m², indicating that malnutrition remains an important concern in the management of chronic kidney disease.  The 2020 KDOQI guidelines emphasize the importance of routine nutritional assessment and individualized nutritional interventions to maintain muscle mass, reduce complications, and improve quality of life.⁸

The results demonstrated a marked reduction in serum urea and creatinine levels after hemodialysis, with statistical significance (p < 0.01). Specifically, the mean serum urea concentration decreased from 27.7 ± 9.5 mmol/L before dialysis to 16.0 ± 5.8 mmol/L after dialysis. The mean serum creatinine level declined from 712.3 ± 225.6 to 474.4 ± 166.9 µmol/L. These findings indicate that hemodialysis using single-use dialyzers was effective in removing urea and creatinine. This statistically significant reduction (p < 0.01) is consistent with previous studies by Pham Van Hien et al. (2022) conducted at Cho Ray Hospital and Nguyen Van Tuan et al. (2021) at Nghe An Friendship General Hospital, which also reported significant post-dialysis decreases in urea and creatinine levels (p < 0.001).^{2, 3} The reduction of uremic toxins suggests that single-use dialyzer membranes provide effective diffusive clearance, meeting the requirements for safe and stable hemodialysis..

The mean Kt/V in our study was 1.33 ± 0.32, with 69% of patients achieving the KDOQI-recommended target (Kt/V ≥ 1.2). This proportion was higher than that reported by Nguyen Thanh Cong et al. (2025) at People’s Hospital 115, where the rate of adequate Kt/V was 61.5%, suggesting that the use of single-use dialyzers may contribute to improved dialysis adequacy.⁴ The mean Kt/V observed in this study is comparable to that reported in a multicenter study in China by Xu et al. (2025), which documented a mean Kt/V of 1.29 ± 0.27 among hemodialysis patients.⁵ However, despite achieving the target mean Kt/V, the proportion of patients meeting the adequacy threshold (69%) remains lower than the target recommended by the Vietnamese Ministry of Health, which stipulates that at least 90% of patients should achieve these indices.⁹ In comparison with international centers, a report by Saran et al. in the United States showed that 87% of maintenance hemodialysis patients achieved a Kt/V ≥ 1.2.¹⁰ This highlights a gap in dialysis quality that requires further improvement. Achieving adequate Kt/V depends not only on the type of dialyzer used but also on dialysis duration, blood flow rate, and patients’ nutritional status.¹¹

The analysis of associations showed that Kt/V was significantly influenced by sex, dialysis duration, BMI, and type of vascular access (p < 0.05). Female patients had a higher mean Kt/V than male patients (1.44 ± 0.33 vs. 1.23 ± 0.28). This finding is consistent with the study by Jeon et al. (2024) and can be explained by the smaller urea distribution volume in females compared with males, resulting in higher Kt/V values for the same dialysis dose.⁶ Dialysis sessions lasting longer than 3 hours had a significantly higher mean Kt/V (1.50 ± 0.21) compared with sessions lasting ≤ 3 hours (1.00 ± 0.23). This demonstrates that extending dialysis duration improves the clearance of urea and creatinine. Similarly, a study by Datu et al. (2023) reported a significantly higher mean Kt/V in patients undergoing 4-hour dialysis sessions (M = 1.38) compared with those receiving 3-hour sessions (M = 1.17).¹⁰ Patients with higher BMI (≥ 23 kg/m²) had lower Kt/V values (1.14 ± 0.32). This finding aligns with the observations of Xu et al. (2025), who reported that larger body volume reduces the amount of urea removed per unit volume of blood.5 Moreover, Xu et al. (2025) indicated that overweight and obese patients had a 5.516- and 15.761-fold higher risk, respectively, of receiving inadequate dialysis compared with patients with normal BMI.⁵ Patients using an arteriovenous fistula (AVF) or internal jugular venous catheter achieved higher Kt/V values than those using femoral venous catheters. This may be explained by the lower blood flow rates and higher risk of obstruction associated with femoral catheters. These findings are consistent with the report by Nguyen Van Tuan and Nguyen Thi Thuy Linh (2021).³

The overall complication rate in this study was 33%. Hypertension (19%) and hypotension (12%) were the two most common complications observed. This rate of blood pressure instability (31% in total) is comparable to the findings reported by Nguyen Van Tuan and Nguyen Thi My Thanh (2021), who documented a blood pressure fluctuation rate of approximately 28.4%.⁷ The use of single-use dialyzers may contribute to a reduction in complications related to infection and inflammatory reactions associated with dialyzer reuse. However, hemodynamic events, particularly blood pressure fluctuations,still persist, indicating the need for stricter control of ultrafiltration rates.

The results of this study indicate that the use of single-use dialyzers in hemodialysis at Hanoi Medical University Hospital is effective, with a proportion of patients achieving adequate Kt/V (69%) that is higher than that reported in several domestic studies. This finding supports the current trend toward the use of single-use dialyzers in accordance with contemporary clinical practice guidelines, contributing to improved treatment efficacy and a reduced risk of cross-infection. The factors that significantly influenced dialysis adequacy included dialysis duration, sex, BMI, and type of vascular access. To further improve dialysis effectiveness, optimization of dialysis duration (ensuring ≥ 4 hours in accordance with general recommendations) and appropriate weight management strategies tailored to patients’ BMI are necessary. In addition, Kt/V remains a central measure in assessing dialysis adequacy and has a significant impact on patients’ clinical outcomes.

Limitations

This study was limited by its cross-sectional design and relatively small, single-center sample, which restrict causal inference and generalizability. In addition, the absence of a comparison group using reused dialyzers prevented direct evaluation of the long-term clinical and cost-effectiveness of single-use dialyzers.

5. CONCLUSIONS

The study results demonstrate that the use of single-use dialyzers in hemodialysis at Hanoi Medical University Hospital is effective, with 69% of patients achieving the target Kt/V. Dialysis adequacy was significantly influenced by dialysis duration, sex, BMI, and type of vascular access (p < 0.05).

REFERENCES

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2. Pham Van Hien, Ngo Hong Thanh Truc, Nguyen Minh Tuan, et al. Evaluation of the effectiveness of hemodialysis by the Kt/V index among patients with hemodialysis at the hemodialysis department of Cho Ray Hospital. Vietnam Medical Journal. 2022;519(2). doi:10.51298/vmj.v519i2.3679
3. Nguyen Van Tuan, Nguyen Thị Thuy Linh. The effectiveness of dialysis in patients with end-stage renal disease on hemodialysis in Nghe An General Hospital. Vietnam Medical Journal. 2021;501(2). doi:10.51298/vmj.v501i2.513
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9. Ministry of Health. Guidelines for Hemodialysis Technical Procedures . 2018. Procedure 49 – Regulations on Hemodialysis Quality, 188-190.
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Trần Xuân Ngọc^1,*, Đỗ Gia Tuyển^{1, 2}, Nguyễn Tiến Tú¹, Nguyễn Anh Tuấn¹, Hồ Hà Linh¹, Nguyễn Văn Thanh^{1, 2}, Đỗ Trường Minh^{1, 2}, Hoàng Thị Hiệp¹, Nguyễn Ngọc Long¹

1. Bệnh viện Đại học Y Hà Nội

2. Trường Đại học Y Hà Nội

*Tác giả liên hệ: Trần Xuân Ngọc

Email: ngocxuanphong@hmu.edu.vn