What investigations are recommended for confirming sepsis in a patient presenting with fever and tachycardia?

Recommended investigations to confirm sepsis in a patient presenting with fever and tachycardia include:

• Blood gas analysis including glucose and lactate measurement, as lactate is a marker of illness severity and cellular stress.
• Blood cultures taken ideally before antibiotic administration to identify causative pathogens.
• Full blood count to assess white cell count and platelet levels, which may indicate infection or disseminated intravascular coagulation.
• C-reactive protein (CRP) to indicate infection and/or inflammation.
• Urea, creatinine, and electrolytes to evaluate for dehydration and acute kidney injury.
• Liver function tests to detect liver dysfunction such as cholestasis.
• Clotting screen to identify coagulopathy or disseminated intravascular coagulation.
• Urine analysis and culture, chest X-ray, and other investigations guided by clinical presentation to identify the source of infection.

These investigations help confirm sepsis, identify the source of infection, and guide appropriate management including antibiotic therapy and supportive care.

Additional clinical assessments include: measuring vital signs such as temperature, heart rate, respiratory rate, blood pressure, oxygen saturation, and level of consciousness, and using early warning scores like NEWS2 to stratify risk.

Prompt collection of these samples and investigations is critical, ideally before starting antibiotics, to improve diagnostic accuracy and patient outcomes.

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