Respiratory Tract Defenses

Constant Oxygen Supply and Respiratory Tract Exposure

• All body functions need a constant oxygen supply for metabolic activities
• To supply this oxygen, the respiratory tract has a continuous interface with the external environment, leading to direct exposure to microorganisms
• The respiratory tract is commonly infected by pathogens where complex defense mechanisms protect against harmful pathogens

Upper Respiratory Tract Defense

• The upper respiratory tract includes the nasal cavities, pharynx, and larynx
• Nares and nasal cavities have coarse hairs (vibrissae) and a mucous layer to filter out large particles
• Epithelial tissues and blood vessels in the nasal cavities filter and warm inhaled air
• Surface epithelium secretes antimicrobial peptides with bactericidal effects
• Cilia in the nasal cavities transport trapped particles via the mucociliary escalator
• Sneezing and coughing reflexes expel particulate matter
• Tonsils and adenoids (lymphoid organs) help develop an immune response
• The larynx (voice box) and epiglottis provide mechanical protection; the epiglottis closes during swallowing to prevent aspiration
• Resident bacteria and viruses, like Staphylococcus, Streptococcus, spirochetes, mycobacteria, Pseudomonas, Proteus, and Enterococcus, colonize the upper respiratory tract
• These microorganisms maintain a healthy respiratory status by competing with pathogens and producing bactericidal substances

Lower Respiratory Tract

• The lower respiratory tract begins at the trachea, followed by the bronchi, bronchioles, and alveoli
• Ciliated and mucous-secreting cells in the trachea, bronchi, and bronchioles use the mucociliary escalator to protect against particles that evade upper airway defenses
• Pathogens trapped are driven upward to the larynx and oropharynx where they are swallowed, being destroyed by digestive enzymes in the stomach
• The lower respiratory tract is considered a "sterile site" due to the upper tract's ciliated epithelial lining filtering most inhaled pathogens
• Alveolar macrophages eliminate microorganisms via phagocytosis when pathogens reach the alveoli
• Gas exchange occurs in the alveoli, so keeping them pathogen-free is critical
• Respiratory infections occur when the respiratory epithelium is damaged, or when inhaled pathogens exceed protective mechanisms

Respiratory Tract Infection Establishment

• To establish an infection in the lower respiratory tract, pathogens must avoid:
  • Trapping in the mucociliary layer of the upper airway
  • Phagocytosis by alveolar macrophages
• Infectious airborne organisms must be under 5 µm to remain suspended for a long time and toxic while in the air
• Sufficient infectious organisms must be inhaled and deposited on susceptible tissues
• This prevents innate protective mechanisms in both the upper and lower respiratory tracts from functioning

Inflammatory Response

• Once pathogens infect the respiratory tract, an inflammatory response starts
• Airway epithelial cells secrete pro-inflammatory cytokines like interleukin (IL) and tumor necrosis factor (TNF) after direct stimulation by infecting organisms
• Neutrophils (white blood cells) are recruited to infected alveoli with immune cells and serum components
• Capillary permeability in lungs increases, causing the alveoli to fill with fluid and plasma proteins
• Exudate (cells and fluid) provides a medium for infecting organisms to proliferate and move, preventing gas exchange and causing hypoxia

Influenza, Epidemiology

• Influenza is a highly contagious infection spread rapidly from person to person
• The Centers for Disease Control and Prevention (CDC) tracks outbreaks annually
• The scope and severity vary across areas
• Epidemics affect more than the expected population and occur every 1-3 years, lasting 2-3 months
• Pandemics are global outbreaks or those affecting more people than expected and occur less frequently than local outbreaks
• The H1N1 pandemic in 2009 caused an estimated 151,700 to 575,400 deaths
• Morbidity and mortality were high among those with comorbidities, the very young, and the advanced in age
• The CDC stated the highest influenza burden in the 2017-2018 season since 2009, estimating 48 million illnesses, 22 million doctor visits, 959,000 hospitalizations, and 79,400 deaths
• A reduction in influenza infection occurred in the 2019-2020 reporting 38 million illnesses, 18 million doctor visits, 405,000 hospitalizations, and 22,000 deaths and 2020-2021 seasons reports 16,000 illnesses, 224 hospitalizations, and unreported direct influenza-related deaths due to COVID-19 pandemic mitigation

Influenza Risk Factors

• Age: Young children (under 2) and older adults (over 65) have immature or less active immune systems
• Occupation: Healthcare workers, family caregivers, daycare providers, and early childhood educators are often exposed
• Environmental: Those in dormitories, military quarters, and long-term care facilities are often exposed for long periods
• Immune System: Compromised individuals include those with malignancies, transplant recipients, HIV/AIDS with CD4+ counts under 200 cells/mm3
• Chronic Illness: Those with diabetes, renal failure, asthma, and cardiac/respiratory diseases have higher risks
• Pregnancy: Patients who are pregnant, considering it, or have recently given birth are at greater risk for severe viral pneumonia and mortality

Influenza Types and Transmission

• Human influenza viruses exist in three types: A, B, and C
• Influenza A viruses split further into subtypes by differences in hemagglutinin (H) and neuraminidase (N)
• Influenza B is not broken down into subtypes but categorized by strains
• Influenza types A and B cause epidemics, often in winter, linked to increased hospitalizations and deaths
• Influenza A mutations of the H and N antigens lead to extensive and severe outbreaks
• These mutations let viruses evade host immune systems, making individuals susceptible throughout their lives
• Managing and controlling the impact focuses on influenza A and B
• Influenza C often causes no symptoms or mild respiratory illness; thus, it lacks epidemics and serious public health concerns like influenza A and B
• The primary infection event requires the aerosolization of small droplets (under 5 µm) from sneezing or coughing within 3-6 feet or by contact with fomites
• Infectious agents are then inhaled and deposited on epithelial cells, reproducing and spreading for 4-6 hours throughout the respiratory tract
• The incubation lasts approximately 18-72 hours
• Symptoms and illness rely on the amount of virus and affected respiratory cells
• Virus shedding tends to end 2-5 days after symptoms appear, so individuals remain infectious for 7-10 days

Influenza Clinical Manifestations and Diagnosis

• Clinical manifestations include fever, headache, sore throat, severe nasal congestion, cough, muscle aches, malaise, and fatigue and tend to be worse than a cold
• The gold standard diagnostic is a viral culture of respiratory secretions, taking up to 10 days
• In emergencies and clinics, rapid influenza diagnostic tests (RIDTs) identify virus infections using swabs/aspirates within 30 minutes
• RIDT results depend on the manufacturer's test and virus type
• A negative RIDT does not rule out influenza; consider patient symptoms and history
• Clinicians should not base diagnosis on a test result alone and must use clinical judgment
• Circulating antibodies can be found in the blood within 2 weeks of infection, testing using hemagglutination inhibition, complement-fixation, and enzyme-linked immunosorbent assay

Influenza Treatment

• Primarily, treatment focuses on annual vaccination via inoculation by detected inactivated influenza viruses for up to 80% protection
• Vaccines are reformulated annually to match changes in viral strains
• Side effects are infrequent, with low-grade fever and soreness at the injection site
• Those allergic to eggs cannot receive the current form of the vaccine due to containing an inactive egg protein
• Most appropriate time for vaccination is early fall before the "flu season"
• Symptoms are treated with antipyretics/analgesics, fluid intake, and rest with more critical cases requiring antiviral medications
• Severity, comorbid risk factors, age (over 65), and pregnancy are the guiding factors on utilizing antiviral medications, with best results when initiated within 24 to 48 hours of symptom onset
• Antiviral medications do not "cure" the flu but impair viral replication, reducing severity and duration
• Antibiotic use must be reserved for documented bacterial infections

Influenza Nursing Management

• Clinical Manifestations:
  • Cough
  • Headache
  • Nasal congestion
  • Sore throat
  • Fever
  • Typically are a result of the inflammatory response once the virus has invaded the respiratory epithelium

Influenza Nursing Diagnoses

• Ineffective breathing pattern related to infection/inflammation of the lungs
• Decreased activity tolerance related to hypoxia
• Alteration in gas exchange related to impaired alveolar-capillary interface
• Fluid volume deficit related to insensible losses from fever and tachypnea
• Malaise
• Fever
• Fatigue

Influenza Nursing Interventions

• Assessments:

  • Vital signs:
    • Tachypnea is the bodies 1st compensatory mechanism to decresed oxygen delivery
    • Tachycardia is the bodies 2nd compensatory mechanism as well
    • monitor for Decrease O2 saturation and fever
  • Neurological Function
    • Agitation, restlessness
    • Anxiety, lethargy and fatigue
  • Breath sounds:
    • Monitor for adventitious breath sounds such as rhonchi, crackles, and rales
  • General appearance
    • Sudden onset of fever, chills, muscle aches, and fatigue
  • Cough
    • Nasal congestion, sneezing, rhinorrhea
    • Primary viral pneumonia can be up to 2 weeks with secretions that are white in color and bacterial infections produce purulent nasal discharge
  • peripheral pulses and skin temperature and color
    • Peripheral pulses diminish, and skin becomes moist and pale
    • Peripheral cyanosis is a late sign of tissue hypoxia
  • Laboratory Values
    • Primary respiratory infections may initially cause a respiratory alkalosis which will progress to a respiratory acidosis
  • Positive RIDTs

• Actions

  • Initiate appropriate isolation precautions
  • Administer humidified supplemental oxygen -Position patient in semi- to high Fowler's (head of bed raised to 30 degrees)
  • Administer antipyretics if ordered
  • Administer antiviral if ordered

Influenza Nursing education

• Take antiviral if they are prescribed and take the whole time
• Antiviral dont cure, but just shorten symptoms and prevent complications
• Be sure to get flu vaccine every year

COVID-19, Epidemiology

• In late December 2019, an obscure group of viral pneumonia cases was reported in Wuhan, Hubei Province, China
• A novel (new) coronavirus was identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the outbreak
• Coronavirus disease 2019 (COVID-19) names the symptomatic infection in humans. The source of the original outbreak has yet to be found
• Rapid spread of the new virus led to the World Health Organization (WHO) declaring a pandemic in March 2020
• As of June 2022, over 545 million confirmed cases of COVID-19 had been reported globally, causing over 6.3 million deaths
• COVID-19 manifests from asymptomatic to critical with at risk individuals being:
  • Age (greater than 65 years)
  • Long-term care resident
  • Immunocompromised
  • Cardiovascular disease
  • Hypertension
  • Diabetes
  • Obesity (body mass index [BMI] greater than 30)
  • Respiratory disease
  • Autoimmune disorders
  • Mental health disorders
  • Physical or developmental disabilities
  • Lifestyle (e.g., smoking, substance abuse)
• Worldwide, there is concern over disparities in case rates, outcomes, and deaths among minority communities
• Systemic health disparities place these groups at higher risk for preexisting conditions, thus more risk of severe disease
• Socioeconomic factors that heighten severe COVID-19 illness are multifamily living arrangements, not being able to postpone working, absence of sick time, and unemployment/ and housing insecurity
• Ethnic minorities and people of color have heightened risk for exposure, severe illness, hospitalization, and death

COVID-19 Pathophysiology, Transmission, and Antibodies

• Coronaviruses are enveloped RNA viruses that cause respiratory illness, ranging from the common cold to acute respiratory failure with viral infections, in general, because mutations occur at high rates
• SARS-CoV-2 binds to cells and deposits messenger RNA (mRNA) inside the host cell using ACE2 receptors found in the cell membranes of the lungs, heart, kidney, and intestines, and throughout arterial vasculature
• Viral particles then are released from the infected host cell and enter other cells to replicate
• The large expression of ACE2 accounts for the damage to airways
• ACE2 expression by arterial vasculature activates the intrinsic pathway of the clotting cascade, causing the hypercoagulable state with COVID-19
• The main transmission method is close contact (within 6 feet) with expressed respiratory droplets through coughing, sneezing, laughing, singing, or talking
• Infection can occur if infected droplets land in one's yes, nose, or mouth or by from contact of viral particles on the hands
• Aerosolization of the virus occurs with nebulizer delivery, incentive spirometry, flutter valve, oxygen delivery, airway suctioning, intubation, increasing infection
• Viral survival times varies due to conditions and surfaces
• Antibody production occurs with the immune response; variable responses has been seen

COVID-19 Precautions Treatment

• Patients suspected of COVID-19 infection are placed in a single occupancy negative with a closed door
• If negative pressure rooms or not available, WHO recommends cohorting patients by COVID status of suspected, probable, or confirmed
• Aerosolized interventions should be performed using airborne precautions with a closed system filter mechanism, requiring personal protective equipment (PPE)
• COVID-19 symptoms range from no symptoms to life-threatening, developing anywhere from 2-14 days of close contact
• COVID-19 is most contagious within 2 days before symptoms up till 5 days after
• Treatment focuses on early recognition, mitigating viral exposure, and spread
• With community spread, all respiratory symptoms are treated as COVID-19 after sick contact or recent travels
• Treatment for other etiologies should be delayed with immediate due to high infectivity
• Since most cases of COVID are mild, it keeps the health burden light

COVID-19 testing, and bias

• Gold standard testing utilizes RT-PCR RNA swabs or outpatient test kit
• In patients of color, there’s a high frequency of occult hypoxemia or lack of oxygen
• Ensure proper placement of saturation probe and the temperature of patient’s skin
• If available, use alternative site measurement

COVID-19 Treatment

• Goal of care is to prevent severe illness, hospitalization, and death at 92-96%
• For individuals with respiratory conditions, aim for 88% -92%
• Prevent hyperoxic induced lung injury

COVID-19 Nursing Process

• Assessment

• Subjective data • Fever • Fatigue • Nasal passage congestion • Headache

• Diagnosis The nursing diagnosis is the main things to monitor

• Ineffective breathing patterns to monitor

• Impaired gas exchange

• Activity tolerance

• Interventions • Oxygen application, humidification to prevent the drying up of the mucosal layer • Turn the head every 2hrs to maintain skin integrity • Medicate the patient as per order, such as giving bronchodilators. • Pt position with hight fallowers

Community Acquired Pneumonia

• 3-4 million cases reported annually ⅓ in patients 65 y/o
• Higher risk in those 65 yo and older

CAP Epidemiology

• In 2017 there were over 9093 cases of TB or 2.8 people over 100,000
• Declined 1.8% in 2016
• Majority of cases were caused by reactivated TB

CAP Risk factors

• Nursing home patient
• Comorbidity such as cancer, HIV, and immunosuppression can be a risk factor for pneumonia
• Pt with immunocompromised
• Prolonged aspiration, and intubation and trach can lead to these complications as well.

Pneumonia

• Inflammation in the lungs resulting from bacteria, viral, or fungal infections
• Enters airway via infected particles/ aspiration from Oropharynx
• Avoids the body’s 2 main ways of defense
• Organism localizes to more or one lobe Bacterial causes infection leading to septicemia or Septic shock Older patients/chronic illnesses have high mortality rates

Pneumonia s/s treatment

• Can be mild to severe
• Manifestations include fevers, tachypnea, tachycardia
• More severe cases may result to
  • Blood-streaked sputum
  • Hypotension -Dysrhythmia
• Elevated WBC count
• Gram stain to reveal category or offending organism
• Sputum is the best to confirm organism’s diagnosis
• Chest X-ray will show if anything of the sorts are there

PNEUMONIA Nursing Diagnoses/Problem List

• Perfusion and respiratory distress
• Peripheral perfusion
• Gas exchange
• Risk of confusion

Interventions

• Assess VS
• Assess RR + O2 status
• Neuro function d/t hypoperfusion Pulm hygiene such as inspiration and breathing

Tuberculosis Epidemiology

• TB is a life threatening respiratory lung infection caused by bacterium
• M. tuberculosis
• ⅓ of the world’s population is infected
• monitored by the CDC

TB pathophysiology

• Aerosol transmission d/t close contact situations.
• Small droplets called m. tuberculosis are tiny and remain suspended in the air and there can be up to 3100 droplets can be released in one cough. Those that can evade mococillary escalate Then the infection begins where tb is either Latent - no s/s and it gets incapsulated and isn’t contagious Primary- immunocompromised can’t be incapsulated Progressives- symptomatic tb that can spread and produce rusty/ bloody colored sputum. Resistant TB - caused primarily by human exposure.

TB Nursing Process

• Assess/ VS. SpO2 VS Neurofunction.
• RR

Tuberculosis interventions

• Airborne Isolation
• antibiotic therapy