Anaesthesiology - Respiratory Failure Flashcards
(29 cards)
Acute severe asthma
Features
Management
Acute COPD exacerbation
Features
Management
Pneumothorax
Features
Management
Tension Pneumothorax
Features
Management
Pneumonia
Features
Management
Pulmonary embolism
Features
Management
Acute pulmonary edema
Features
Management
List neuromuscular causes of respiratory failure
Grey matter:
* Brainstem herniation
* High C-cord compression
Neuron:
* Motor neuron disease
* Polio
* Lead poisoning
* GBS
* CIPD
* Muscular/ myotonic dystrophies
* Inflammatory dystrophies
NMJ:
* MG
* Botulism
* Lambert-Eaton myasthenia syndrome
Respiratory suppressants:
- Propofol
- Opioids
- BDZs
Paralytics:
- Depolarizing and non-depolarizing muscle relaxants
Causes of poor lung compliance
Pulmonary edema
Pulmonary embolism/ nfarct
Interstitial lung diseases
Respiratory distress syndrome
Surfactant deficiency
Visceral pleura thickening secondary to TB, Asbestos, Hemothorax
External compression:
- Pneumothorax
- Pleural effusion
- Massive ascites
Causes of high airway resistance
Obstructive lung diseases:
- Asthma
- COPD
- Central airway obstruction
- emphysema
- Bronchospasm/ laryngospasm
Airway compression:
- upper airway inflammation
- mediastinal masses
Devices in ICU to assist breathing
Devices to avoid dry air induced airway inflammation
Ventilation types:
* Mechanical ventilator/ Positive pressure ventilation (PPV)
* Non-invasive ventilation (NIV): Continuous positive airway pressure (CPAP) or Bilevel positive airway pressure (BIPAP)
Devices for oxygen delivery
- Nasal cannula
- Standard face mask
- Venturi mask
- Partial rebreather mask
- Non-rebreather mask
Humidifiers:
- active humidification with respiratory humidifier
- Passive humidification with Heat and Moisture Exchanger (HME)
Basic mechanical ventilator modes/ IPPV
- Continuous Mandatory Ventilation (CMV)
- Volume Control (VC)
- Pressure Control (PC)
- Synchronised Intermittent Mandatory Ventilation (SIMV)
- Pressure Support (PS)
Compare volume control and pressure control ventilators
Advantages
Volume control
- Set tidal volume for each breath
- Inspiration ends after delivered of set tidal volume, at set respiratory rate or on demand
- Variable pressure
Advantage: Guaranteed volume and minute volume (Vt x RR)
Pressure control
- Set pressure for each breath
- Delivered at set RR or on demand
- Guaranteed airway pressure
- Volume and minute volume variable
Advantage:
o Increased patient comfort requiring less sedation
o Improved patient-ventilator synchrony
o Early liberation from mechanical ventilation
o More homogeneous gas distribution (less regional alveolar overdistension)
Mechanical ventilation/ PPV
- Advantages
- Indications
Advantages of mechanical ventilation
Improves gaseous exchange
- ↑ Oxygenation by improving V/Q matching
- ↑ Alveolar ventilation
- Reverse acute respiratory acidosis
Relieve respiratory distress
- ↓ Work of breathing
- ↓ Respiratory muscle fatigue
General indications:
· Respiratory failure not adequately controlled by other means
· Cardiac or respiratory arrest
· Failure to protect airway with GCS < 8
· Hemodynamic instability (severe hypotension)
Laboratory criteria
Lung function test (LFT)
- Vital capacity < 10 mL/kg
- FEV1.0 < 10 mL/kg
Arterial blood gas (ABG)
- PaO2 < 7.3 kPa despite O2 supplementation
- PaCO2 > 6.7 kPa with pH < 7.32
Indications and contraindications of non-invasive PPV
Modes of non-invasive ventilation (NIV)
Indications
Continuous positive airway pressure (CPAP): delivery of a single level of positive airway pressure continuously
Indications: if the primary problem is hypoxemia
- Most commonly used in treatment of cardiogenic pulmonary edema, sleep-related breathing disorders and obesity hypoventilation syndrome
- Better for patients in acute pulmonary edema (APO) or near-drowning
Bilevel positive airway pressure (BiPAP): delivery of a preset inspiratory positive airway pressure (IPAP) for inhalation and expiratory positive airway pressure (EPAP) for exhalation, pressure changes per breathing pattern
Indication: if the main problem is hypoventilation
- Used for COPD patient
Identify the type of mechanical ventilation shown here
Changes with which pathologies
Identify the type of mechanical ventilation shown here
Changes with which pathologies
Disadvantages of pressure control and volume control ventilators
no strategy proven superior in oxygenation, decrease in work of breathing and mortality
Excessive volume/ pressure:
- Volume > 10 ml/kg (IBW) ➔ Volutrauma
- Plateau Pressure > 30 cmH2O ➔ Barotrauma
Low volume:
- Volume < 2.2 ml/kg (IBW) ➔ Dead Space Ventilation
- Low minute ventilation (Vt x RR) ➔ Hypercapnia
Metrics set on ventilator
Mode of ventilation: depends on disease, operator familiarity
Inspiration: expiration timing: 1:2 (closest to normal physiology), 1:1 for poor compliance (increase inspiration time and oxygenation), 1:4 for poor elastance (Increase expiratory time to avoid hyperinflation)
Tidal volume: 6-8ml/kg of Ideal Body Weight
Respiratory rate: Adjust to pCO2
FiO2: Adjust to SpO2, aim for 90-94%, 88-92% for COPD
Positive end-expiratory pressure (PEEP): 5-15cm H2O
· Positive pressure applied during exhalation via resistor in exhalation port
· Beneficial in terms of preventing alveolar collapse, decrease shunting, increase O2 via alveolar recruitment and improved compliance
· Higher PEEP (10-15) to recruit collapsed lungs and improve oxygenation
Tidal volume based on ideal body weight
Dangers of hypoxia and hyperoxia due to oxygen delivery
Compare NIV and IPPV
advantages and disadvantages/Side effects
Respiratory distress
All signs
Clinical presentation from respiratory distress to arrest to failure
