H.T. is a 55-year-old man in the status of post neurosurgery secondary to head trauma sustained from a motor vehicle crash. H.T. is intubated and sedated but has spiked multiple fevers (maximum temperature, 39°C) over the past 24 hours. There is no change in oxygen requirements and laboratory test values are stable with normal renal function. Blood and urine culture and sensitivity results are pending. 

 a) Dr. Fernando, a medical officer of the night shift, made an enquiry on the concern of possible central nervous system ("CNS") bacterial source for empirical antibiotic coverage. (4 marks) 

(i) Suggest TWO common pathogens the empirical treatment should cover. 

(ii) List TWO antibiotics in combination as empirical treatment for H.T. (Note: antibiotic dosages are not required) 

b) In addition, Dr. Fernando was concerned about the antibiotic penetration into the CNS for the empirical treatment of suspected meningitis. (6 marks) 

(i) List THREE drug characteristics which determine the antibiotic penetration into CNS (i.e. Cerebrospinal fluid ("CSF") concentration). 

(ii) Explain how each drug characteristic influences the antibiotic penetration into CNS. 

c) On the day of intensive care unit (“ICU”) admission, you performed medication reconciliation on H.T.'s drug profile and revealed that H.T. is receiving adalimumab SC injection for rheumatoid arthritis. 

(i) Explain the rationale in reviewing the bacteria coverage for H.T.'s empirical treatment. 

(ii) What is the additional bacteria coverage to be considered? 

(iii) Suggest an antibiotic to be added to the empirical treatment for H.T. 

(3 marks) 

d) Given H.T.'s decline in mental status on day 2 of ICU admission, Dr. Fernando asked if adjuvant corticosteroid would be indicated for H.T. 

(2 marks) 

(i) Give ONE benefit of adjuvant corticosteroid use in suspected bacterial meningitis. 

(ii) Suggest the corticosteroid and the route of administration for use in H.T.