AKT · Infections/Viral infectionslow yield

COVID-19

SARS-CoV-2 coronavirus — respiratory infection with multisystem and thrombotic complications

Overview

Infection with SARS-CoV-2, ranging from asymptomatic/mild upper-respiratory illness to viral pneumonia, ARDS and a hyperinflammatory/thrombotic syndrome. Risk of severe disease rises with age, obesity, immunosuppression and chronic disease. Management is tiered by severity: supportive for mild disease; antivirals for high-risk non-hospitalised patients; and dexamethasone (± immunomodulators) plus thromboprophylaxis for those needing oxygen.

Recognise

Fever, cough, breathlessness, fatigue, myalgia, anosmia/ageusia (loss of smell/taste — a useful pointer), sore throat, GI symptoms
Severe disease: hypoxia (sometimes 'silent'), viral pneumonia/ARDS, hyperinflammation, VTE (raised D-dimer); post-COVID syndrome ('long COVID')
Higher severity risk: older age, obesity, immunosuppression, chronic cardiorespiratory/renal disease, diabetes, pregnancy

Red flags

Hypoxia / respiratory failure → oxygen + escalation (cross-ref respiratory failure); VTE risk → thromboprophylaxis
Rapid deterioration / hyperinflammation → critical care; immunosuppressed → consider antivirals early

Differentials & how to tell them apart

Influenza / other viral pneumoniaoverlapping — PCR distinguishes; anosmia favours COVID

Bacterial pneumoniafocal consolidation, may coexist

Pulmonary embolismCOVID is prothrombotic — consider PE in deterioration with raised D-dimer/hypoxia

Investigations

SARS-CoV-2 PCR/lateral-flow; oxygen saturations (detect silent hypoxia); CXR/CT (bilateral peripheral ground-glass/consolidation); FBC (lymphopenia), CRP, D-dimer, U&Es; ABG if hypoxic.

Management

Tiered by severity: supportive/antivirals if high-risk → dexamethasone + thromboprophylaxis if needs oxygen

1Confirm with PCR/lateral-flow and assess severity (oxygen saturations — beware silent hypoxia). Mild disease → supportive care; high-risk non-hospitalised patients → antivirals per current eligibility.Gate: Oxygen requirement → DEXAMETHASONE (steroid) is the key treatment, plus thromboprophylaxis (COVID is prothrombotic); add immunomodulators in severe disease per guidance.
2Escalate oxygen/respiratory support (CPAP/ventilation) for respiratory failure; treat VTE; manage post-COVID syndrome; vaccination prevents severe disease.

Mild/non-hospitalised: supportive care; antivirals for high-risk — high-risk non-hospitalised patients → antivirals (e.g. nirmatrelvir-ritonavir or alternatives) per current UKHSA/NICE eligibility

Needs oxygen: DEXAMETHASONE (corticosteroid) — the key intervention for hypoxic/oxygen-requiring COVID (RECOVERY); add an immunomodulator (e.g. tocilizumab/baricitinib) in severe disease per guidance

Thromboprophylaxis (LMWH) — COVID is prothrombotic — VTE prophylaxis for inpatients; treat confirmed VTE

Oxygen/respiratory support + vaccination (prevention) — CPAP/ventilation as needed; vaccination reduces severe disease

Key points

SARS-CoV-2: fever/cough/breathlessness + anosmia. Severity-tiered: supportive (mild) → antivirals (high-risk non-hospitalised) → DEXAMETHASONE + thromboprophylaxis (needs oxygen; COVID is prothrombotic — watch for PE). Beware silent hypoxia. Vaccination prevents severe disease. (Eligibility/agents shift — check current UKHSA/NICE.)

Monitor & prognosis

Oxygen saturations/work of breathing, CRP/D-dimer, VTE, deterioration; long-COVID follow-up.

Most recover; severity and mortality rise with age/comorbidity; thrombotic and post-acute complications occur.

Source: NICE NG191 / UKHSA COVID-19; cross-ref respiratory failure, cardiovascular (PE)