Sepsis & Undifferentiated Fever
Recognise organ dysfunction, assess exposure-specific causes and combine prompt treatment with source control and reassessment.
Quick revision ↓ Medical Dictionary
01Recognise dangerous infection
Sepsis involves life-threatening organ dysfunction related to infection. New confusion, reduced urine output, poor perfusion, hypotension or respiratory compromise can be more important than the temperature. Older or immunocompromised adults may not mount a fever. Use the applicable early-warning and sepsis pathway, but escalate concerning clinical deterioration even when a numerical score is not dramatic. Consider non-infectious mimics without delaying necessary urgent care.
02Immediate priorities
Assess airway, breathing and circulation, obtain appropriate cultures if this does not delay treatment, and investigate the likely source. High-risk sepsis or shock needs prompt antimicrobials through the urgent pathway. Fluid resuscitation should be individualised and reassessed for perfusion and overload, especially with cardiac or renal disease. Persistent shock may require critical-care support and vasopressors rather than repeated unreviewed fluid administration.
03Find and control the source
History and examination may identify pneumonia, urinary obstruction, abdominal infection, skin infection or a device-related source. Imaging and procedures are selected to answer that question. An obstructed infected system or drainable collection may not improve with antibiotics alone. Track lactate in context; elevation suggests concern but is not specific for sepsis, and a normal value does not exclude important infection-related illness.
04Fever in the local context
Ask about travel, mosquito exposure, unsafe water, animal contact, TB risk and immune status. Malaria, dengue and enteric fever require exposure-aware testing and management, not diagnosis from fever pattern alone. A single negative early test may be insufficient in a convincing presentation. Bleeding, severe abdominal pain, persistent vomiting or deterioration around defervescence can signal severe dengue risk and require urgent assessment.
05Review and prevention
Reassess observations, perfusion, urine output, laboratory trends and response to source control. Narrow antimicrobials when appropriate and review the continuing need rather than treating for an arbitrary duration. For dengue, avoid aspirin and NSAIDs because of bleeding risk and use a careful fluid plan. At discharge, explain expected recovery, warning symptoms and follow-up. Persistent fatigue after severe illness should not obscure new deterioration.
High-Yield Revision
- Absence of fever does not exclude sepsis.
- Source control can be as important as antimicrobial choice.
- Reassess fluid response and overload after each intervention.
Common Pitfalls
- Do not use a normal lactate as the sole exclusion test.
- Do not give aspirin or NSAIDs for suspected dengue fever.
References & Further Reading
Read the relevant guideline sections alongside these original clinical teaching cases. Local pathways, available services and individual patient factors determine care.
Reference review: 27 September 2026. Consult current local protocols for prescribing, procedures and escalation.