Initial Investigations

I. CBC and differential, Urea, Creatinine, electrolytes, hepatic transaminases and total bilirubin

II. Blood Cultures

A. At least 2 sets (detect 80-90% bloodstream pathogens in critically ill patient)
B. From each lumen of CVC AND
C. Peripheral site if possible (help to differentiate the colonization/contimination vs true infection)

III. Investigations (e.g. culture) from other site of suspected infection as indicated

A. Stool
B. Skin aspiration/biopsy
C. Respiratory specimens:

i) BAL in patients with pulmonary infiltrates of uncertain etiology.

ii) NPA/BAL, particularly during outbreak or during winter
D. CXR if respiratory signs/symptoms
E. Inflammatory markers: ESR, CRP. Procalcitonin yields inconsistent results and therefore is NOT recommended for routine use