NCLEX Review Guide: COVID-19 and Adult Infectious Diseases

SARS-CoV-2 Virus Characteristics

• COVID-19 is caused by SARS-CoV-2, a novel coronavirus that primarily affects the respiratory system but can cause multi-organ dysfunction including cardiovascular, neurological, and gastrointestinal complications.
• The virus spreads through respiratory droplets, aerosols, and contact transmission, with an incubation period of 2-14 days (median 5-6 days).
• Asymptomatic and pre-symptomatic transmission can occur 48-72 hours before symptom onset, making infection control challenging in healthcare settings.

Symptom Spectrum and Severity Classification

• Common symptoms include fever, cough, shortness of breath, fatigue, body aches, headache, loss of taste/smell, with symptom severity ranging from asymptomatic to critical illness requiring mechanical ventilation.
• Severe disease indicators include oxygen saturation <94%, respiratory rate >30/min, PaO2/FiO2 ratio <300, and signs of respiratory distress or shock.
• Long COVID symptoms can persist for weeks to months, including fatigue, brain fog, dyspnea, and cardiovascular complications affecting patient quality of life.

Personal Protective Equipment and Isolation Precautions

1. Implement contact and droplet precautions with airborne precautions for aerosol-generating procedures
2. Don PPE in correct sequence: hand hygiene, gown, mask/respirator, eye protection, gloves
3. Use N95 respirator or higher-level protection during intubation, bronchoscopy, or nebulizer treatments
4. Doff PPE safely in designated area with proper hand hygiene between each step

• Monitor respiratory status closely including oxygen saturation, respiratory rate, and work of breathing as patients can deteriorate rapidly, especially those with comorbidities.
• Administer supplemental oxygen as prescribed, position patient prone if appropriate, and prepare for potential escalation to high-flow nasal cannula or mechanical ventilation.

Pharmacological Interventions

• Antiviral medications like Paxlovid (nirmatrelvir-ritonavir) are most effective when started within 5 days of symptom onset for high-risk patients to reduce hospitalization and death.
• Corticosteroids (dexamethasone) are indicated for hospitalized patients requiring supplemental oxygen, with typical dosing of 6mg daily for up to 10 days.
• Monoclonal antibodies may be used in specific high-risk patients, but effectiveness varies with viral variants and requires careful patient selection and monitoring.

Complications and Critical Care

• Acute respiratory distress syndrome (ARDS) is the most serious pulmonary complication, requiring low tidal volume ventilation and prone positioning to improve oxygenation.
• Thromboembolism risk is significantly elevated, necessitating anticoagulation prophylaxis and monitoring for signs of pulmonary embolism or deep vein thrombosis.
• Cardiovascular complications include myocarditis, arrhythmias, and acute coronary syndrome, requiring continuous cardiac monitoring and troponin surveillance in severe cases.

Home Care Instructions

• Educate patients on isolation requirements for 5-10 days from symptom onset and until fever-free for 24 hours without fever-reducing medications to prevent community transmission.
• Provide clear instructions on symptom monitoring, including when to seek emergency care for difficulty breathing, persistent chest pain, confusion, or bluish lips/face.
• Emphasize importance of vaccination and boosters for household contacts, proper mask wearing, and environmental cleaning with EPA-approved disinfectants.