A nurse is assessing the cerebrospinal fluid (CSF) of a client suspected to have meningitis. Which CSF parameter indicates bacterial or fungal infection?
A.
Cloudy appearance.
B.
Increased pressure.
C.
Decreased glucose.
D.
Elevated protein levels.
The correct answer and Explanation is :
In assessing cerebrospinal fluid (CSF) for meningitis, the correct parameter that indicates bacterial or fungal infection is:
C. Decreased glucose.
Explanation
Cerebrospinal fluid (CSF) analysis is a critical diagnostic tool for determining the presence and type of meningitis. Meningitis, an inflammation of the protective membranes covering the brain and spinal cord, can be caused by various pathogens, including bacteria and fungi.
- Decreased Glucose:
- In bacterial and fungal meningitis, the CSF glucose levels are typically decreased. This reduction occurs because bacteria and fungi consume glucose as they proliferate, leading to lower levels in the CSF. Additionally, the inflammatory process in bacterial and fungal infections can impair the transport of glucose across the blood-brain barrier, further contributing to decreased glucose levels. Normal glucose levels in CSF are usually around two-thirds of blood glucose levels. A decrease to less than 40% of blood glucose is a strong indicator of bacterial or fungal meningitis.
- Cloudy Appearance:
- While a cloudy or turbid appearance of CSF may suggest the presence of infection, it is not specific to bacterial or fungal infections. Cloudiness can result from various factors, including the presence of white blood cells, bacteria, or other particulate matter. Thus, while it can be indicative of an infection, it is not definitive for bacterial or fungal etiology.
- Increased Pressure:
- Elevated CSF pressure is commonly seen in meningitis but is not specific to bacterial or fungal infections. Increased pressure can result from increased intracranial pressure due to inflammation or other factors and does not provide a definitive indication of the type of pathogen.
- Elevated Protein Levels:
- Elevated protein levels in the CSF are indicative of an inflammatory process and are commonly seen in both bacterial and viral meningitis. However, elevated protein alone does not differentiate between bacterial and fungal infections.
In summary, decreased glucose levels in the CSF are the most specific indicator of bacterial or fungal meningitis, as these pathogens significantly impact glucose metabolism and transport.