Acute Respiratory Failure Flashcards
What percentage of the air is o2?
21%
Explain the anatomy of the lungs
Trachea Right lung - upper - middle - lower Left lung - upper - lower bronchi alveoli
What is the primary function of the respiratory system
exchange of respiratory gases, oxygen and carbon dioxide between the circulatory blood and the lungs by diffusion across the alveolar – capillary membrane
What is Perfusion?
the mechanism the body uses to exchange gases between the atmosphere and the blood
What is ventilation?
the movement of gases into and out of the lungs by inspiration and expiration
What is the difference between perfusion and ventilation?
Ventilation - the mechanics
perfusion - the exchange
What kinds of ventilation (mechanical) problems can happen?
OUTSIDE • Neuro patients • Myastenias gravis (decompression of spinal cord) • Guillain-Barré syndrome (auto immune) • Muscular problem • Diaphragm • Muscles around rib cage INSIDE • PE • Pulmonary oedema
What kinds of exchange issues can occur?
Decrease level of oxygen due to atmosphere changes Low blood volume Blockage preventing the exchange • PE • Pulmonary oedema
What does respiratory failure result in?
insufficient oxygen is transferred to the blood resulting in hypoxaemia (decrease in PaO2) or inadequate carbon dioxide is removed, resulting in hypercapnia (increased PaCO2
What are the clinical manifestations of respiratory failure?
CNS alteration in mental state - restlessness, agitation, anxiousess
Respiratory - increased rate less depth
CVS - Higher HR
Skin - cool clammy
Neuro muscular - may feel weak, tremor, seizure
How is diagnosis made for acute respiratory failure?
Clinical Observation/assessment
Chest X-Ray
ABG Analysis
Explain acute respiratory distress syndrome (ARDS)
ARDS refers to a form of non cardiogenic pulmonary oedema resulting in hypoxaemic
respiratory failure
How quickly can ARDS develop?
24-48 hours
give 5 examples of aetiologies which can lead to the development of ARDS
¡ - Sepsis (most common) ¡ - Pneumonia ¡ - Aspiration and other chemical pneumonitis ¡ - Trauma (second most common); lung contusion, penetrating lung injury ¡ - Pancreatitis ¡ - Multiple blood transfusions ¡ - Smoke or toxic gas inhalation ¡ - Drugs ¡ - Burns ¡ - Near drownings
What are the stages of ARDS?
- Injury stage
- Reparative or proliferative stage
- Fibrotic stage
Explain the injury stage?
- 1–7 days after direct lung injury or host insult
- Inflammatory response – presence of oedema
- Fluid interstitial (surrounding)
- ↑ Work of breathing (WOB)
- ↑ Respiratory rate
- ↓ Tidal volume
- Interstitial and alveolar edema (noncardiogenic pulmonary edema)
- Shunting of pulmonary capillary blood O2
Explain the Reparative or Proliferative stage
- 1–2 weeks after initial lung injury
- Alveolar sac are filled with fluid containing neutrophils and erythrocytes
- Lung becomes dense
- Lung compliance continues to ↓
- If reparative phase persists, widespread fibrosis results
Explain the Fibrotic stage
• 2–3 weeks after initial lung injury • Lung is completely remodeled by sparsely collagenous and fibrous tissues • ↓ Lung compliance • ↓ Area for gas exchange
What are the early signs of ARDS?
Dyspnoea, tachypnoea, cough and restlessness Chest auscultation may reveal scattered crackles ABG - mild hypoxia with respiratory alkalosis
Chest x-ray may be normal or may show minimal scattered interstitial infiltrates
What are the late signs of ARDS?
- ↑ work of breathing
- Pulmonary function ↓
- compliance and ↓ lung volumes (notably↓ Functional Residual Capacity (FRC)
- Mental state changes (as hypoxia worsens)
- CXR - diffuse and bilateral interstitial and alveolar infiltrates progressing on to a white out picture
- As the condition degenerates, hypoxaemia, hypercapnia and metabolic acidosis ensue
Why does renal failure occur in ARDS?
- Occurs from decreased renal tissue oxygenation from hypotension, hypoxemia, or hypercapnia
- May also be caused by nephrotoxic drugs used for infection associated with ARDS
What nursing assessments can be done to detect ARDS?
- History of lung disease
- Exposures to lung toxins
- Tobacco use
- Related hospitalisations
- Extreme obesity
- Use of O2, inhalers, nebulisers,
- Previous intubation
- Thoracic or abdominal surgery
- Exercise
What sudden changes should you look for upon nursing assessment?
Name 8
- Diaphoresis
- Dizziness
- Dyspnea, wheezing, cough, sputum, palpitations, swollen feet
- Changes in sleep pattern
- Fatigue
- Headache
- Chest pain
- Anxiety
- Restlessness
- Agitation
- Pale, cool, clammy or warm, flushed skin
- Use of accessory muscles
- Shallow breathing with increased respiratory rate
- Tachycardia progressing to bradycardia
- Extra heart sounds
- Abnormal breath sounds
- Hypertension progressing to hypotension
- Abdominal distention, ascites
- Confusion, delirium
- Changes in ABGs
- Decreased tidal volume
- Abnormal x-ray
Following recovery what should you expect of the airway and ABG results?
- Pao2 within normal limits or at baseline
- Sao2 >90% ( dependant on patients presentation)
- Patent airway
- Clear lungs on auscultation
What O2 therapy should be used?
- High-flow systems used to maximize O2 delivery
- Spo2 continuously monitored
- Give lowest concentration that results in Pao2 60 mm Hg or greater
- Patients will commonly need intubation with mechanical ventilation because Pao2 cannot be maintained at acceptable levels
What happens in mechanical ventilation?
• PEEP at 5 cm H2O (depends on person)
▪ Opens collapsed alveoli
• Higher levels of PEEP are often needed to maintain Pao2 at 60 mm
Hg or greater
• High levels of PEEP can compromise venous return
▪ ↓ Preload, CO, and BP
What is PEEP?
P - positive
E - End
E - Expiratory
P - Pressure
by using peep it keeps the alveoli open
patient then has a higher chance of a better exchange
What are the risks of PEEP?
If the person has pneumonia the lungs cannot fill adequately and the air flow with transfer to other lung which can make the lung pop
How do we evaluate recovery?
- No abnormal breath sounds
- Effective cough
- Normal respiratory rate, rhythm, and depth
- Appropriate use of accessory muscles
