When someone is fighting severe pneumonia in the ICU, doctors need to know exactly which germ is causing it to choose the right treatment. This study tested whether a simple nasal swab could match the more invasive lung fluid test for finding those germs.
Researchers compared nasal swabs to lung fluid samples from 105 critically ill and immunocompromised patients. They found high agreement for major bacterial threats like Acinetobacter and Staphylococcus, with the nasal swab correctly identifying them over 80% of the time. However, the swab was less reliable for viruses and fungi, and its usefulness for tracking germ changes over time was limited.
The study shows that a nasal swab can be a helpful early tool when a lung test isn't immediately available, but it doesn't replace the lung fluid test for a complete picture. This is especially important for high-risk ICU patients who need precise answers.
The main caveat is that this was an observational study, so it shows an association, not a cause-and-effect proof. The sample size was modest, and the results for viruses and fungi were weaker, meaning the lung test remains essential for a full assessment.