Question

Benjamin, a 21-year-old male is brought to the emergency department by his parents who state that he has "not been himself" for the past 18 hours. He is a college student who was home for the weekend complaining of headaches. The parents inform the phyician that their son has no past medical history. They are not aware that he is taking any medication. History and physical findings per the physician are positive for headaches and altered mental status with a tactile fever during the past two days. Body temperature on examination is 38°C orally; heart rate of 115 beats per minute, blood pressure 112/70, and a respiratory rate of 22 breaths per minute. His oxygen saturation is 97% on room air. His head and neck exhibited nuchal rigidity. Results of a CT scan of the brain shows no mass, shift, bleeding, or edema. Opening pressure of a lumbar spinal tap is >190mmHO (normal <180mmH₂O)

Laboratory resuits: Comments: Indicates the presence of WBCs, RBCs, bacteria, and protein
1. What is the significance of a lower than normal cSF/serum glucose result?
2. Identify the abnormal findings in this patient's history and physical
3. What are the patient's abnormal CSF analysis test results?
4. What is the most likely diagnosis and why?

Answer 1

A lower than normal CSF/serum glucose result indicates a likely bacterial infection, consuming glucose. The patient's symptoms and abnormal CSF test results, including increased white blood cells, presence of bacteria, and decreased glucose, strongly suggest bacterial meningitis as the diagnosis.

Step-by-step explanation:

Significance of Low CSF/Serum Glucose

The significance of a lower than normal cerebrospinal fluid (CSF)/serum glucose result indicates a potential bacterial infection. Glucose is normally present in both serum and CSF, and a decrease in the CSF glucose concentration relative to the serum suggests that bacteria are consuming the glucose for energy, which is common in bacterial meningitis.

Abnormal Findings in Patient History and Physical

The abnormal findings include a body temperature of 38°C, heart rate of 115 beats per minute, respiratory rate of 22 breaths per minute, and nuchal rigidity. These symptoms, combined with the patient's altered mental status and headaches, suggest an infection within the central nervous system.

Abnormal CSF Analysis Test Result

The patient's abnormal CSF analysis results are an opening pressure of >190mmH2O (normal <180mmH2O), the presence of white blood cells (WBCs), red blood cells (RBCs), bacteria, and elevated protein levels. These findings are indicative of an inflammatory process in the CSF, such as meningitis.

Most Likely Diagnosis

The most likely diagnosis for the patient is bacterial meningitis. This is supported by the signs of infection (fever, increased heart rate, increased respiratory rate), specific symptoms (headaches, nuchal rigidity, altered mental status), and abnormal CSF findings (elevated white blood cells, presence of bacteria, decreased glucose, and elevated protein)