Sepsis — Life-Threatening Response to Infection

Under normal circumstances, the immune system releases chemical signals into the bloodstream to combat localised infections. Sepsis develops when this inflammatory mechanism spirals out of control, triggering widespread systemic inflammation, microvascular blood clotting, and compromised blood vessel permeability throughout the entire vascular tree.

Without swift clinical intervention, this cascade impairs perfusion to essential organs, culminating in tissue hypoxia, acute organ dysfunction, and septic shock—a severe subtype marked by profound hypotension. In cancer patients, neutropenia (a severe drop in infection-fighting neutrophils) substantially accelerates this progression.

Sepsis represents one of the most critical oncological emergencies. Due to treatment-induced bone marrow suppression, oncology patients may not present with standard inflammatory signs such as pus or localised redness; a subtle fever or general confusion might be the sole warning sign.

Recognising early warning signs—including chills, rapid heart rate, breathlessness, and temperature spikes—enables rapid antibiotic administration. Every hour of delay in treating sepsis increases mortality risk, making prompt reporting of infection signs vital for patient safety.

Rapid diagnosis involves screening for the Systemic Inflammatory Response Syndrome (SIRS) or qSOFA criteria. Key laboratory tests include urgent full blood counts (to detect neutropenia), blood cultures from peripheral veins and central lines, serum lactate measurements (reflecting tissue hypoperfusion), C-reactive protein (CRP), and comprehensive metabolic panels evaluating renal and hepatic function.

Sepsis can complicate any cancer, but risks are highest in haematological malignancies such as acute myeloid leukaemia, non-Hodgkin lymphoma, and multiple myeloma. It is also common among patients receiving intensive myelosuppressive chemotherapy for solid tumours, such as lung, ovarian, or gastrointestinal cancers, or those with central venous catheters.

Sepsis mandates immediate emergency management known as the 'sepsis bundle'. Clinicians administer empirical broad-spectrum intravenous antibiotics, aggressive intravenous fluid resuscitation, and supplemental oxygen. Vasopressors like noradrenaline are deployed if septic shock develops. In neutropenic patients, granulocyte colony-stimulating factors (G-CSF) may be added to stimulate white blood cell production.