Communicable & Infectious Disease · Topic 6 of 23
COVID-19 & Emerging Pathogens
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COVID-19 & Emerging Pathogens
SARS-CoV-2 spreads by respiratory droplets and aerosols. The danger is silent hypoxia — a low SpO₂ in a patient who looks comfortable.
Isolation & PPE
Isolate on suspicion — before the test result
Bronchoscopy is also aerosol-generating. AIIR = airborne infection isolation room. Precautions last at least 10 days after symptom onset plus 24 hours fever-free with improving symptoms; up to 20 days if severely ill, longer if immunocompromised (CDC, May 2023 — durations change). During community spread, facilities may use respirators and eye protection for all patient care. WHO allows a medical mask for routine care; US CDC uses a respirator for all care.
What you'll see
Loss of smell or taste stands out among common viral symptoms
Complications include ARDS, stroke (even in young patients), acute kidney injury and cardiac injury. Long COVID brings weeks to months of fatigue, brain fog and dyspnea.
Labs & diagnostics
Nasopharyngeal RT-PCR is the standard COVID-19 test
D-dimer is followed for clotting risk. CRP and ferritin are inflammatory markers that may be checked in hospitalized patients.
Red flags
Treatment
Act on SpO₂ below 90%, not on how the patient looks
Prone positioning, including awake proning when not intubated
Dexamethasone 6 mg daily for up to 10 days
Not for mild illness without hypoxiaPaxlovid within 5 days of symptom onset
Other antiviral
Nursing priorities
RT-PCR or rapid antigen?
A negative antigen test doesn't clear a symptomatic patient
| RT-PCR | Rapid antigen | |
|---|---|---|
| Role | The standard test (nasopharyngeal swab) | Faster option |
| Speed | Slower | Faster |
| Sensitivity | Higher | Lower — misses cases |
Teach your patient
A COVID-19 patient can look fine with an SpO₂ under 90% — act on the number. Isolate on suspicion: N95, gown, gloves and eye protection.
Sources · Features, Evaluation, and Treatment of Coronavirus (COVID-19) (StatPearls) · Infection Prevention and Control Recommendations for Healthcare Personnel During COVID-19 (CDC) · Manual Prone Positioning in Adults (Critical Care Nurse, AACN) · The pathophysiology of happy hypoxemia in COVID-19 (Respiratory Research) · Pulse Oximetry (StatPearls) · Myths and Facts about COVID-19 Vaccines (CDC) · Follow your facility's protocol for COVID-19 isolation.
COVID-19 & Emerging Pathogens
A patient on 4 liters of oxygen desaturates when turned to their side — but improves when you turn them onto their stomach. The intervention that saved thousands of lives costs nothing.
SARS-CoV-2 causes COVID-19, transmitted primarily via respiratory droplets and aerosols, with a spectrum from asymptomatic to critical illness (ARDS, multi-organ failure). Key clinical features: fever, cough, dyspnea, fatigue, myalgia, anosmia/ageusia, and GI symptoms. Complications include hyperinflammatory response (rapid clinical deterioration with markedly elevated inflammatory markers), thromboembolic events (DVT, PE, stroke — even in young patients), acute kidney injury, and cardiac injury. Long COVID involves persistent symptoms (fatigue, cognitive dysfunction, dyspnea) for weeks to months after acute infection. Diagnosis: RT-PCR (nasopharyngeal swab, gold standard, high sensitivity); rapid antigen testing (lower sensitivity, useful for point-of-care). Treatment stratified by severity: mild/moderate in high-risk patients — nirmatrelvir/ritonavir (Paxlovid) within 5 days of symptom onset; hospitalized requiring supplemental oxygen — dexamethasone 6 mg daily for up to 10 days (reduces mortality); hypoxic patients — prone positioning improves oxygenation by redistributing ventilation to better-perfused lung regions. Remdesivir may be used in selected hospitalized patients, especially those with earlier disease or requiring supplemental oxygen but not yet on advanced ventilatory support, per current protocol. Precautions: at minimum, standard plus contact and droplet with eye protection for suspected/confirmed COVID-19. Use N95 or higher for aerosol-generating procedures (intubation, nebulization, high-flow nasal cannula, bronchoscopy) and when facility or community transmission risk warrants broader respirator use per current CDC guidance and facility policy. Vaccination: mRNA and protein-based platforms; recommended for all eligible individuals. Emerging pathogen preparedness principles: surveillance systems, rapid diagnostic deployment, surge capacity planning, and supply chain resilience. Nursing: monitor for rapid deterioration (silent hypoxia — patient appears comfortable despite SpO2 <90%), proning protocols, thromboprophylaxis assessment, isolation with dedicated equipment, and emotional support for isolated patients.
Key Distinctions
COVID-19 is tested as a clinical respiratory disease management scenario on NCLEX, not as a public health policy question. Dexamethasone reduces mortality ONLY in patients requiring oxygen — it is harmful in mild disease without hypoxia. Prone positioning is for hypoxic patients, not all COVID patients. Silent hypoxia (comfortable appearance with dangerously low SpO2) is characteristic and requires continuous pulse oximetry — do not rely on patient appearance. PPE requirements follow facility policy and current CDC guidance; N95 is specifically required for aerosol-generating procedures.
Clinical Pearl
Comfortable patient, SpO2 of 82% — COVID taught us to trust the monitor over the appearance. Silent hypoxia kills the ones who look fine.
Knowledge Check
3 quick questions on the must-knows for this topic.
What position improves oxygenation in hypoxic COVID patients?
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