Med Surg 2: Infectious Respiratory Conditions Flashcards

Influenza Transmission and Environmental Factors

• Virulence and Seasonality: Influenza is more virulent in the winter months due to environmental changes that affect the virus's physical structure and transmission.

  • Temperature Effects: Decreased temperatures cause the lipid layer of the virus to harden. This hardening allows the virus to survive outside the host's body for longer durations compared to warmer temperatures.

  • Air Density and Humidity: Drier air in the winter lacks moisture to weigh down respiratory droplets, allowing them to travel significantly farther distances through the air.

• Precautions: Healthcare providers must implement DROPLET PRECAUTIONS when caring for patients with influenza.

Influenza Contagion and Clinical Progression

• Virus Families: Influenza is caused by several virus families, categorized primarily into types A, B, and C.

• Period of Contagion: Influenza is highly contagious.

  • Adult Contagiousness: Individuals are contagious approximately $24\,\text{hours}$ before symptoms appear.

  • Post-Exposure Duration: Contagion lasts for $5\,\text{days}$ after exposure, though a $2\,\text{day}$ contagion window after symptom onset is more typical.

• Length of Illness:

  • Acute Phase: Symptoms typically last between $5-7\,\text{days}$.

  • Residual Phase: Post-acute symptoms, such as significant fatigue, can persist for up to $2\,\text{weeks}$ after the acute phase resolves.

• Prognosis: Complications can be severe, potentially leading to pneumonia or death.

• Vaccination Impact: Receiving the influenza vaccine can either prevent the infection entirely or reduce the duration and severity of the illness.

Symptomatology of Influenza Strains

• Onset: Symptoms have a rapid onset, usually appearing within $3-6\,\text{hours}$ of infection. Symptoms typically present between $1-4\,\text{days}$ after exposure.

• General Manifestations: Symptoms vary by strain but commonly include:

  • Headache.

  • Muscle aches (myalgia).

  • Fever.

  • Chills.

  • Fatigue and generalized weakness.

• Strain-Specific Presentation:

  • Flu B: Specifically known to include gastrointestinal symptoms such as nausea and vomiting (often referred to as "stomach flu"). This strain carries a high risk of leading to secondary bacterial pneumonia.

Complications of Influenza

• Mild Sinus Infections: Often occur as a minor secondary complication.

• Pneumonia: Recognized as the most serious complication. It usually develops as a secondary bacterial infection. It causes the alveoli to fill with fluid. Signs include sharp chest pain, high fever, and the production of thick, discolored mucus.

• Bronchitis: Involves the inflammation of the bronchial tubes, resulting in a persistent, harsh cough and shortness of breath (SOB).

• Exacerbation of Chronic Conditions: The flu triggers severe asthma attacks and worsens existing Chronic Obstructive Pulmonary Disease (COPD).

• Heart Inflammation: Cardiac involvement can occur.

• Sepsis: A life-threatening medical emergency resulting from the systemic response to infection.

Diagnostic Testing for Influenza

• Symptom-Based Diagnosis: Clinical presentation often guides initial treatment.

• Rapid Influenza Diagnostic Testing (RIDT): While quick, these tests have an increased rate of false positives. It is emphasized that the patient should be treated immediately if symptoms are observed, regardless of the RIDT result.

• Reverse Transcription Polymerase Chain Reaction (RT-PCR): This is the preferred test due to higher accuracy.

• Testing Philosophy: Providers treat the specific symptoms present. Treatment should proceed even if the test result is positive or negative.

Influenza Treatment and Nursing Interventions

• Supportive Care: Treatment is primarily supportive to manage symptoms.

• Antiviral Medications: Medications like Tamiflu should be initiated within $24-48\,\text{hours}$ of the first observation of symptoms. Patient education must emphasize that these do not replace the need for a vaccine.

• Oxygen Therapy: Indicated if hypoxia (low blood oxygen levels) is present.

• Mechanical Ventilation: May be required as needed (PRN) for severe respiratory failure.

Yearly Influenza Vaccination and Prevention Strategies

• Annual Formulation: Vaccines are reformulated every year based on the current prevailing strains.

• Target Population:

  • Recommended for all patients aged $\ge 6\,\text{months}$.

  • Recommended for patients $\ge 65\,\text{years}$ with chronic illnesses.

  • Immunocompromised Patients: Strongly recommended; these individuals typically require increased dosages.

• Infection Control Strategies:

  • Frequent hand washing.

  • Coughing or sneezing into the elbow rather than the hand.

  • Staying home when symptomatic.

  • Avoiding close contact with others.

Influenza Viral Classifications and Pandemic Potential

• Immune Response Resistance: Respiratory viral infections are generally self-limiting, but they have the ability to mount an immune response that reduces the effectiveness of previously developed antibodies.

• Strains and Hosts:

  • Type A: Can affect both humans and animals.

  • Type B: Primarily affects humans and is a common cause of epidemics.

  • Type C: Affects both humans and pigs, usually resulting in mild upper respiratory infections.

  • Type D: Primarily affects cattle; it is currently unknown if it can affect humans.

• Collective Ethics: Prevention is stated as "everyone’s responsibility."

Medication Focus: Influenza Antiviral Agents

• Primary Agents: Oseltamivir, Zanamivir, Peramivir, and Baloxavir.

• Concurrent Therapy: These may be given alongside antibiotics (ATB) if a secondary bacterial infection is present.

• Mechanism of Action: They inhibit a specific viral enzyme that allows the virus to penetrate respiratory cells, thereby preventing viral spread within the respiratory tract.

• Efficacy Window: Most effective when started $24-48\,\text{hours}$ after symptoms begin.

• Clinical Utility: Use is determined by the patient's age, overall presentation, and risk for complications like pneumonia. These medications are proven to reduce hospitalizations in high-risk patients.

COVID-19: Clinical Manifestations and Symptoms

• Etiology: Responsible for variations of the common cold; includes strains originating from birds and animals.

• Incubation Period: Symptoms typically appear between $2-14\,\text{days}$ after exposure.

• Key Symptoms:

  • Fever and chills.

  • Shortness of breath (SOB).

  • Muscle weakness, pain, and body aches.

COVID-19 Diagnosis and Treatment Classes

• Testing Modalities:

  • Point of Care (POC) and @Home diagnostic tests.

  • Antibody Tests: Serum blood tests used to detect past infections.

• Management: Most cases are managed with home isolation.

• Pharmacotherapy:

  • Nirmatrelvir-Ritonavir: An oral combination protease inhibitor.

  • Remdesivir: An antiviral drug administered via IV infusion over a period of $3\,\text{days}$.

  • Bebtelovimab: A monoclonal antibody given as a single-dose IV infusion.

• Monoclonal Antibody Definition: Identical antibody molecules produced by a single clone of cells or a specific cell line.

COVID-19 Vaccination Types and Protocols

• Pfizer-BioNTech: An mRNA vaccine series of $2$ injections given $3-8\,\text{weeks}$ apart.

• Moderna: An mRNA vaccine series of $2$ injections given $4-8\,\text{weeks}$ apart.

• Novavax: A protein subunit vaccine containing pieces of the spike protein that causes COVID-19.

• Johnson & Johnson Janssen: A single-injection viral vector vaccine. It is associated with a specific risk of Thrombosis with Thrombocytopenia Syndrome (TTS).

Pneumonia: Pathophysiology and Etiology

• Definition: Inflammation of the alveoli.

• Major Pathogens:

  • Bacterial: Streptococcus pneumoniae is the most common bacterial cause.

  • Viral: Includes Influenza A, Influenza B, and COVID-19.

  • Fungal: Pneumonia can also be fungal in origin.

• Non-Infectious Causes:

  • Inhalation of toxic gases.

  • Chemical fumes.

  • Aspiration of water ($H_2O$) or food.

• Epidemiology: Leading cause of death; higher prevalence in winter due to people staying inside more in close quarters.

Categories and Risk Factors for Pneumonia

• Community-Acquired Pneumonia (CAP): Acquired in the community setting, not a hospital. Often caused by Streptococcus pneumoniae or viruses. Typical symptoms include cough, fever, shortness of air (SOA), and chest pain.

• Nosocomial Pneumonia: Includes Hospital-Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP).

• Risk Factors: Age $\ge 65$, smoking, excessive alcohol use, and underlying conditions like asthma, COPD, or diabetes.

• Gas Exchange Impairment: Infection causes the formation of thick exudate in the lungs, which directly reduces gas exchange.

Clinical Manifestations and Respiratory Assessment

• Assessment Findings: Crackles on auscultation. The nursing intervention is to "fix what you can hear."

• Common Symptoms:

  • Headache, chills, and high fever.

  • Cough and sputum production.

  • Severe/sharp chest pain.

  • Muscle weakness.

• The Tripod Position: Patients should be encouraged to sit upright and lean forward (tripod position) to facilitate breathing.

Special Considerations for the Older Adult with Pneumonia

• Vital Signs and Status: Assess for hypotension, orthostatic changes, and dehydration.

• Symptom Presentation: Symptoms in the elderly are often vague, making clinical assessment difficult.

• Diagnostic Essential: Chest X-rays (CXR) are essential for early diagnosis in this population due to the lack of classic symptoms.

• Positioning: Hypoxia may make it difficult for the patient to lie down flat.

Diagnostic Evaluation for Pneumonia

• Laboratory Tests: Sputum culture, Complete Blood Count (CBC), Lactic Acid, and Arterial Blood Gases (ABGs) to establish baseline $O_2$ and $CO_2$ levels.

• Chest X-Ray (CXR): This is the definitive test for pneumonia. Note: Structural changes may not appear on CXR for up to $2\,\text{days}$ after symptoms begin.

Medical Management and Nursing Interventions for Pneumonia

• Respiratory Support: Oxygen therapy and the use of an Incentive Spirometer.

• Pharmacotherapy:

  • Antimicrobials: Specific to the invading organism identified.

  • Bronchodilators: e.g., Albuterol.

  • Expectorants: e.g., Mucinex or Robitussin.

  • Steroids: e.g., Prednisone.

• Prevention: Vaccinations including PPSV23 and PCV15.

  • Target Group for Vaccine: Aged $\ge 65$ or aged $\ge 19$ if immunocompromised.

Pneumonia Prevention and Post-Acute Care

• General Prevention: Hand washing, avoiding crowds during peak season, frequently changing respiratory equipment, and following strict aspiration precautions.

• Readmission: There is a high high $30\text{-day}$ readmission rate for pneumonia.

• Education: Fatigue, weakness, and a residual cough can last for weeks. Patients MUST complete all anti-infective therapies.

• Prognosis: When sepsis occurs alongside pneumonia, the risk of death is high.

Tuberculosis (TB): Pathophysiology and Infection Stages

• Causative Agent: Mycobacterium tuberculosis. Prior to COVID-19, it was the world's leading cause of death from a single infectious agent.

• Precautions: Highly contagious; requires AIRBORNE PRECAUTIONS.

• Screening: Annual screening is common.

• Disease Phases:

  • Initial Infection: Primarily affects the upper lobes of the lungs and lymph nodes.

  • Latent Infection: An inactive period following initial infection. It is not contagious during this phase. It can last for years or decades before symptoms appear.

  • Secondary Infection: Reactivation of the disease in a previously infected person. This is most likely in older adults, those with chronic illness, or those with HIV due to decreased immunity.

Clinical Manifestations and Assessment of Tuberculosis

• Onset: The patient typically reports a very slow onset, and the disease is often advanced before detection.

• Symptoms:

  • Fatigue and anorexia.

  • Low-grade fever.

  • Night Sweats.

  • Cough: Produces thick, yellow/green sputum that is often blood-tinged.

  • Chest tightness and dull, aching chest pain.

• Exposure: Close contacts of the patient are encouraged to be tested.

Diagnostic Testing and Screening for Tuberculosis

• Mantoux Test: Considered the most reliable. A positive result is an induration of $\ge 10\,\text{mm}$. The width of the induration (the hardened area) is measured, not the reddened area.

  • Follow-up: Once a reaction is positive, no further Mantoux testing is ever needed; the patient will receive a yearly Chest X-ray instead.

• Blood Tests: Includes QuantiFERON-TB Gold Plus, the T-SPOT, and Calmette-Guerin. A positive blood test indicates infection but cannot distinguish between latent and active stages.

• Sputum Culture: Used to confirm diagnosis and monitor treatment.

  • Monitoring: Done every $4\,\text{weeks}$ during treatment. The patient is no longer contagious once a negative result is obtained.

• Chest X-Ray: Completed upon a positive test result and then annually to ensure the disease is not active.

Medical Management and Treatment Regimens for TB

• Therapy Duration: Traditional regimens last $6-9\,\text{months}$. A shorter $4\text{-month}$ regimen exists (Isoniazid, Rifapentine, Moxifloxacin, and Pyrazinamide).

• Adherence: Strict adherence is mandatory.

• Directly Observed Therapy (DOT): A practice where healthcare workers observe the patient taking their medication. This significantly improves outcomes.

• Resistant TB:

  • MDR-TB: Multidrug-resistant TB.

  • XDR-TB: Extensively drug-resistant TB.

  • Patients contracting TB from a resistant source will also have a resistant strain. These require aggressive treatment with $3$ or more drugs for $2-3\,\text{months}$ up to a year, strictly under DOT.

Pharmacotherapy for Tuberculosis: First-Line Drugs

• Isoniazid (INH):

  • Administer on an empty stomach to ensure absorption.

  • Instruct patient to take B-complex vitamins to prevent depletion.

  • Avoid Alcohol: Alcohol potentiates liver effects.

  • Report: Dark urine, yellow eyes, bruising/bleeding (signs of liver toxicity).

• Rifampin:

  • Reduces effectiveness of oral contraceptives; use additional forms of birth control.

  • Causes reddish-orange staining of skin, urine, and contact lenses.

  • Avoid Alcohol; report all other medications as it has many interactions.

• Pyrazinamide (PZA):

  • Asses for history of Gout (increases uric acid formation).

  • Causes photosensitivity; avoid direct sunlight and report sunburns.

  • Drink at least $8\,\text{oz}$ of water to flush uric acid.

• Ethambutol:

  • Drink at least $8\,\text{oz}$ of water to flush uric acid.

  • Vision Assessment: Must assess vision regularly. Can cause optic neuritis, which can lead to blindness.

  • Assess for history of Gout.

Rhinosinusitis: Etiology and Clinical Presentation

• Causes: Can be viral or bacterial; often follows seasonal allergies, the common cold, or the flu.

• Facial Pain: Over the cheek, tenderness to percussion over sinuses, or referred pain to the temple/back of the head.

• Bacterial Indicators: Purulent drainage, post-nasal drip, sore throat, fever, and fatigue.

• Treatment: Decongestants and antihistamines based on the underlying etiology.

Peritonsillar Abscess: Diagnosis and Urgent Care

• Definition: A rare complication of acute bacterial tonsillitis involving a collection of pus behind the tonsils.

• Signs/Symptoms:

  • One-sided throat swelling.

  • Severe pain and muffled voice ("hot potato voice").

  • Swollen lymph nodes and SOB.

• Medical Emergency: Stridor or drooling indicates a possible airway obstruction and requires immediate treatment.

• Treatment: Antibiotics, steroids, and potentially surgical drainage of the abscess.

Inhalation Anthrax: Stages and Risk Exposure

• Etiology: Bacterial spore infection. Usually a skin infection but deadly if inhaled.

• At-Risk Populations: Veterinarians, farmers, and those encountering animal wool, bone meat, or skin.

• Prodromal Stage (Early):

  • Lasts $2-4\,\text{days}$.

  • Treatment MUST start during this time for efficacy.

  • Symptoms: Fever and fatigue.