Evidence for pulmonary microembolization during hemodialysis.

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Nephrology

Background:

• Extracorporeal circulation, such as during hemodialysis, can lead to the formation of blood microaggregates.
• These microaggregates may cause complications, including pulmonary microembolization.
• The impact of hemodialyzer type on microaggregate generation and subsequent physiological changes requires further investigation.

Purpose of the Study:

• To investigate the formation of microaggregates during extracorporeal blood circulation in two types of hemodialyzers.
• To assess the physiological consequences of microaggregate formation, specifically pulmonary changes.
• To evaluate the efficacy of venous line microemboli filters in mitigating these adverse effects.

Main Methods:

• Utilized screen filtration resistance to quantify microaggregate generation in heparinized blood circulated through two hemodialyzer types.
• Monitored arterial blood gases, including oxygen levels and alveolar-arterial oxygen difference, to detect pulmonary complications.
• Assessed the impact of implementing venous line microemboli filters on blood gas parameters and filtration resistance.

Main Results:

• Increased screen filtration resistance indicated microaggregate generation during extracorporeal circulation with both hemodialyzer types.
• Unfiltered or inadequately filtered dialysis led to arterial blood deoxygenation and widened alveolar-arterial oxygen difference, consistent with pulmonary microembolization.
• The use of venous line microemboli filters significantly improved or reversed the observed blood gas abnormalities and reduced screen filtration resistance.

Conclusions:

• Hemodialysis can generate blood microaggregates, potentially leading to pulmonary complications.
• Inadequate filtration during hemodialysis poses a risk of pulmonary microembolization.
• Venous line microemboli filters are effective in preventing or reducing microaggregate-related complications during hemodialysis, improving patient safety.