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Acute Respiratory Failure

Terms in this set (35)

Gas Exchange
1. Ventilation= movement of O2 and CO2 in and out of alveoli.
2. Diffusion of O2 and CO2 at pulmonary capillary
3. Oxygenation blood perfused or transported to the tissues.
4. Diffusion of O2 and CO2 occurs at cellular level. Transport of CO2 to the right side of the heart. Diffusion based on concentration gradients
Work of breathing
Amount of effort required to maintain ventilation, respiratory pattern changes automatically, WOB increases, more energy needed. WOB high, leads to muscle fatigue and eventually respiratory failure.
Compliance
Distensibility or stretch, determined by elasticity "recoil" elastic recoil & compliance are inversely related
Static- measured under condition of no airflow (inspiratory hold)
Dynamic- measured while gases flowing
Resistance
Opposition to gas flow in the airways. Airway length, airway diameter- small tube, spasms, mucus. Flow rate of gases- increased breathing effort
ARDS and compliance
Reduces compliance (stiff lungs)
COPD compliance
Increases in COPD as lungs lose the ability to recoil
Acute respiratory failure type 1
oxygenation failure
Acute respiratory failure type 2
Ventilation failure
Failure of oxygenation
When the PaO2 can't be adequately maintained. Causes- hypoventilation, intrapulmonary shunting, ventilation- perfusion mismatch, diffusion defects, decreased barometric pressure, low cardiac output, low hemoglobin level
Hypoventilation
drug overdose, neurologic disorders, abdominal or thoracic surgery
Intrapulmonary shunting
Blood shunted from right to left side of heart without oxygenation. Areas of the lung are inadequately ventilated but are adequately perfused. Causes- atrial or ventricular septal defect, atelectasis, pneumonia, pulmonary edema
Ventilation Perfusion mismatch V/Q
If either ventilation or perfusion is decreased. Blood and oxygen are not coming to the same location in the same amount. Causes- pneumonia, pulmonary edema, pulmonary embolism
Diffusion defects
Diffusion of O2 and CO2 does not occur. Causes- fluid in alveoli, pulmonary fibrosis
Low cardiac output
Must be adequate to maintain tissue perfusion
Low hemoglobin
hemoglobin is necessary to transport oxygen
Tissue hypoxia
Some conditions prevent tissues from using oxygen despite availability. Results in anaerobic metabolism and lactic acidosis
Failure of ventilation
Hypercapnia related to alveolar hypoventilation- decrease in ventilation and hypoxemia, V/Q mismatch
Assessment of respiratory failure
Neuro- shows earliest signs of hypoxemia and hypercapnia
Interventions of respiratory failure
Maintain a patent airway, optimize O2 delivery, minimize O2 demand, identify and treat the cause of ARF, prevent complications, provide adequate rest, avoid unnecessary physical activity, reduce agitation, restlessness, fever, sepsis, and patient ventilator desynchrony
Medical management of respiratory failure
Oxygen, bronchodialators, corticosteroids, sedation, transfusions, therapeutic paralysis, nutritional support, hemodynamic monitoring.
ARF in COPD
Worsening V/Q mismatch. Causes- acute exacerbations, CHF/ pulmonary edema, dysrhythmias, pneumonia, dehydration, and electrolyte imbalances
Medical management of COPD in ARF
NPPV, O2, ventilation, bronchodilators, corticosteroids, antibiotics, sedatives
ARF in Asthma
Exacerbation of asthma. Causes- bronchodilators no longer working, noncompliance w/ medications
Community acquired pneumonia
Developed outside hospital. Have no been hospitalized or LTC for 2 weeks.
Health care acquired pneumonia
Hospitalized for 2 or more days within 90 days of developing
Hospital acquired pneumonia
Occurs greater than 48 hours after hospital admission
Ventilator associated pneumonia
Developed while on the ventilator. Aspiration of bacteria from oropharynx or gastrointestinal tract, many potential causes.
Patho of VAP
Organisms in lower respiratory tract to overwhelm defense mechanisms. Causes- aspiration, inhalation, spread from another infected area. Impaired mucociliary clearance
Prevention of VAP
Influenza and pneumococcal vaccinations. Bundle, hand washing, standard precautions, surveillance, prevent infection
VAP Bundle
Elevate HOB 30-45 degrees, awaken daily to assess readiness to wean and extubatne, stress ulcer disease prophylactic, VTE prophylaxis, oral care.
Treatment of VAP
Bacteria specific antibiotic theraphy
ARF- Pulmonary embolus
Virchow's triad- venous stasis, altered coagulability, damage to vessel wall. Embolus results in a lack of perfusion to ventilated alveoli
PE assessment
Symptoms of DVT, chest pain, dyspnea, tachycardia, tachypnea, hemoptysis, crackles, wheezes, hypoxemia
Complications and prevention of PE
Medications (heparin)
Heart failure, death, obstructive shock
Cystic fibrosis
Genetic disorder. Mutation in chloride transport results in "sticky" mucus that obstructs glands, lungs, pancreas, liver, testes, salivary glands, thick mucus in lungs is medium for infection, chronic bronchitis and ARF considered to be a disease of childhood improvements in care, have prolonged life expectancy
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