Certified Registered Nurse Infusion (CRNI) Practice Exam 2025 - Free CRNI Practice Questions and Study Guide

A 0.2-micron filter is specifically designed to remove microorganisms such as bacteria and fungi from solutions. This filter's size is ideal for trapping organisms that are typically larger than the filter's pore size.

Bacteria generally range from about 0.5 to 5.0 microns in size, making a 0.2-micron filter effective at removing most of these pathogens. Additionally, fungi can also be captured due to their size, which usually falls within or exceeds the 0.2-micron range. While endotoxins are much smaller than 0.2 microns, they are not living organisms and cannot be effectively removed by 0.2-micron filters; however, the presence of bacteria or fungi might imply potential contamination issues, making these filters essential in maintaining sterility in infusions.

The filter does not effectively remove viruses, which are typically smaller than 0.2 microns. Heavy metals cannot be filtered out by size exclusion methods like this, as they are dissolved ions and require different filtration techniques, such as activated carbon filters or ion exchange. Allergens, which can include a wide range of particles, may vary in size, and while some could be removed by a 0.2-m