Combined FMEA and Cause–Effect Analysis Method for Risk Assessment of Failures Impacting Hemodialysis Water Quality

Abstract

INTRODUCTION: Hemodialysis patients are exposed weekly to large volumes of dialysis water, making water quality a critical determinant of patient safety. Failures in dialysis water treatment systems may lead to chemical contamination, microbiological proliferation, endotoxin exposure, and biofilm formation, resulting in severe clinical complications. Despite the importance of risk prevention, few studies have applied failure mode and effects analysis (FMEA) to assess risks associated with hemodialysis water treatment. This study aimed to evaluate potential failures affecting dialysis water quality using a combined FMEA and cause-effect analysis approach. METHODS: A multidisciplinary risk assessment was conducted at the hemodialysis water treatment unit of Hassan II University Hospital in Fez, Morocco. The production chain was divided into four subprocesses: water feeding, pretreatment, treatment, and distribution. Potential failures, causes, and effects were identified through brainstorming sessions and root-cause analysis using an Ishikawa diagram. Each failure mode was scored according to frequency (F), severity (S), detectability (D), and management (M) using predefined five-level ordinal scales. Two indicators were calculated: the classical risk priority number (RPN1 = F × S × D) and a complementary management-adjusted indicator (RPN2 = (F × S)/M). RESULTS: Thirty-nine failure modes were identified across the dialysis water production process. Root causes were classified into three categories: Method and procedure, material and equipment, and physical and environmental factors. Based on classical RPN stratification, 30 failure modes were categorized as low priority, 8 as intermediate priority, and 1 as high priority. The highest-risk failure was a drop in water flow within the pretreatment circuit (RPN1 = 80). Intermediate-priority failures mainly involved alarm malfunctions, reverse osmosis maintenance issues, hydraulic disturbances, inadequate sampling, and temperature instability. The management-adjusted analysis highlighted electrical interruption of the water treatment unit as the failure mode with the greatest control-related concern (RPN2 = 15). CONCLUSION: The combined FMEA and cause-effect analysis effectively identified vulnerabilities affecting hemodialysis water quality and supported prioritization of corrective actions. The approach provides a practical framework for improving dialysis water safety and may be integrated into routine quality management practices, particularly in resource-limited healthcare settings.