JMIR Publications

ABSTRACT

Background:

Taiwan has the world’s highest prevalence of hemodialysis (HD), with arteriovenous fistula (AVF) stenosis representing a critical complication affecting dialysis adequacy and patient outcomes. Traditional AVF monitoring relies on clinical expertise and subjective assessment, potentially delaying stenosis detection.

Objective:

This study aimed to evaluate electronic stethoscope monitoring for early AVF stenosis detection compared to traditional nursing assessment, and identify risk factors associated with AVF stenosis in HD patients.

Methods:

We conducted a 3-month prospective study at National Taiwan University Hospital Yunlin Branch Hemodialysis Center from March to June 2023. Thirty adult HD patients with AVF (>3 months dialysis vintage) were enrolled. AVF sounds were recorded 2-6 times weekly at two locations: 3cm proximal to the anastomosis and the arterial needle insertion site. Sound signals were converted to decibel (dB) measurements using short-time Fourier transform. Clinical and demographic data were collected including monthly albumin levels, blood pressure (BP), dialysis parameters, and medical history. Chi-square tests, t-tests, and logistic regression analysis identified stenosis risk factors.

Results:

Among 30 patients generating 1,462 AVF sound recordings, abnormal AVF sound was defined as <-28.59 dB using three-standard-deviation analysis. One patient developed clinically apparent stenosis during the study period. Retrospective analysis revealed electronic stethoscope detected stenosis one month before clinical diagnosis. Logistic regression identified significant risk factors for stenosis (percutaneous transluminal angioplasties (PTA) within 3 years): diabetes mellitus (OR=18.67, p=0.005), hypertension (p=0.019), body mass index ≤25 (p=0.006), higher mean systolic BP (OR=1.82 per 10mmHg, p=0.018), FX dialyzer type (OR=5.25, p=0.048), and greater number of prior PTAs (OR=2.47, p=0.003).

Conclusions:

Electronic stethoscope monitoring demonstrated potential for earlier AVF stenosis detection compared to traditional clinical assessment. The identified risk factors—including a novel association with FX dialyzer use—can guide targeted surveillance protocols. Implementing objective acoustic monitoring may improve timely intervention and AVF longevity in high-risk HD patients. Clinical Trial: The study protocol was approved by the Institutional Review Board of NTUH (IRB No. 202302099RINA) and registered at ClinicalTrials.gov (NCT07436559).