Non-Invasive Positive Pressure Ventilation (NIPPV) Flashcards
What are the main indications for Non-Invasive Ventilation (NIV)?
Type 1 Respiratory Failure (oxygenation failure) → CPAP (e.g., APO, pneumonia, ARDS)
Type 2 Respiratory Failure (ventilation failure) → BiPAP (e.g., COPD, neuromuscular disorders)
Other conditions: Sleep apnea, pneumonia, post-op atelectasis, carbon monoxide poisoning
Type 1 and Type 2 Respiratory Failures have distinct treatment approaches.
What are the advantages of NIV over invasive mechanical ventilation?
- Avoids complications of intubation
- Reduces risk of hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP)
- More comfortable for patients
- Reduces need for sedation
- Less resource-intensive and easier to administer
NIV is often preferred for its non-invasive nature and patient comfort.
What are absolute contraindications for NIV?
- Respiratory arrest
- Life-threatening hypoxaemia (PaO2 <60 mmHg on 100% FiO2)
- Cardiovascular instability
- Facial trauma/burns
- Inability to protect airway (e.g., decreased GCS, vomiting, aspiration risk)
Absolute contraindications indicate situations where NIV should not be used.
What are relative contraindications for NIV?
- High risk of aspiration
- Severe claustrophobia
- Excessive secretions
- GI bleeding
- Nasopharyngeal abnormalities
Relative contraindications may require careful consideration before using NIV.
What are common complications of NIV?
- Pressure injuries (nose, cheeks, forehead)
- Gastric distension (risk of aspiration)
- Claustrophobia and discomfort
- Dry mouth, nose irritation, conjunctivitis
- Hemodynamic instability (↓ BP, ↑ HR)
Monitoring for complications is essential when administering NIV.
What are serious complications of NIV?
- Barotrauma (risk of pneumothorax if pressures are too high)
- Aspiration pneumonia
- Hypotension due to increased intrathoracic pressure
Serious complications can pose significant risks to the patient.
What are the two main types of respiratory failure?
- Type 1 (Oxygenation Failure): PaO2 is low, CO2 is normal
- Type 2 (Ventilatory Failure): PaO2 is low, CO2 is high
Understanding the types of respiratory failure is crucial for appropriate treatment.
What are common causes of Type 1 Respiratory Failure?
- Pneumonia
- Acute Respiratory Distress Syndrome (ARDS)
- Acute Pulmonary Oedema (APO)
These conditions primarily affect oxygenation.
What are common causes of Type 2 Respiratory Failure?
- COPD
- Severe asthma
- Neuromuscular disorders
- Chest wall deformities
Type 2 Respiratory Failure typically involves ventilation issues.
How does asthma contribute to Type 2 Respiratory Failure?
- Initially causes hypocapnia due to increased respiratory rate
- If untreated, progresses to permissive hypercapnia as muscles fatigue
The progression of asthma can lead to critical respiratory failure.
How does COPD lead to Type 2 Respiratory Failure?
- Initially may have hypocapnia due to hyperventilation
- As fatigue sets in, CO2 builds up → hypercapnia
COPD management is vital to prevent respiratory failure.
What three factors determine gas exchange in the lungs?
- Ventilation (V) – Breath size
- Perfusion (Q) – Pulmonary blood flow
- Diffusion – Movement of gases between alveoli and blood
These factors are essential for effective gas exchange.
What is a Ventilation/Perfusion (V/Q) mismatch?
- Ventilation issue: Alveoli are not expanding properly (e.g., atelectasis)
- Perfusion issue: Blood flow is disrupted (e.g., pulmonary embolism)
V/Q mismatch can severely impair gas exchange.
Define PEEP and explain its physiological effects.
PEEP (Positive End-Expiratory Pressure) keeps alveoli open at the end of expiration, preventing collapse and improving oxygenation.
* Increases Functional Residual Capacity (FRC) for better gas exchange
* Can reduce venous return, leading to hypotension if too high
PEEP is a common strategy in mechanical ventilation.
What are the major indications for PEEP?
- Oxygenation failure (Type 1 Respiratory Failure)
- Preventing alveolar collapse in conditions like ARDS
PEEP is often used in critical care settings.
What are the key differences between CPAP and BiPAP?
- CPAP: Continuous pressure throughout the breathing cycle → Used for oxygenation issues (e.g., APO)
- BiPAP: Different pressures for inhalation (IPAP) and exhalation (EPAP) → Used for ventilation and CO2 clearance (e.g., COPD)
Understanding the differences is crucial for appropriate device selection.
How does BiPAP improve gas exchange?
- IPAP (Inspiratory Positive Airway Pressure): Increases tidal volume → Improves ventilation (↓ PaCO2)
- EPAP (Expiratory Positive Airway Pressure): Prevents alveolar collapse → Improves oxygenation (↑ PaO2)
BiPAP is effective for patients with ventilation needs.
What are the different types of NIV masks?
- Nasal masks: Common for home CPAP users
- Full-face masks: Standard in ED and ICU
- Bridge-free masks: Reduce nasal pressure injuries but expensive
- Helmet NIV: Used during COVID-19 to reduce claustrophobia
The choice of mask can affect patient comfort and efficacy.
What are the initial settings when starting NIV?
- FiO2: 100% (1.0)
- PEEP/EPAP: Start at 5 cmH2O
- IPAP (for BiPAP): Start at 10 cmH2O
- Backup respiratory rate: 12-16 breaths/min
Initial settings may vary based on patient condition.
How is NIV effectiveness assessed?
- Monitor BP and HR (risk of hypotension)
- Repeat ABG after 1 hour to check CO2 and oxygenation
Regular assessment is key to ensuring NIV is effective.
How do you adjust NIV settings based on blood gases?
- Hypoxia (low PaO2) → Increase FiO2 and PEEP
- Hypercapnia (high PaCO2) → Increase IPAP/pressure support
Adjustments should be made based on clinical response and ABG results.
How is a patient weaned off NIV?
- Reduce FiO2 by 10% every 30 minutes
- Gradually lower IPAP/EPAP by 2.5 cmH2O
- Transition from BiPAP to CPAP, then high-flow oxygen
- Repeat ABG after removal to confirm stability
Weaning must be done carefully to ensure patient safety.
