Anaesthesiology - Respiratory Failure Flashcards

Question 1

Q

Acute severe asthma

Features
Management

Question 2

Q

Acute COPD exacerbation

Features
Management

Question 3

Q

Pneumothorax

Features
Management

Question 4

Q

Tension Pneumothorax

Features
Management

Question 5

Q

Pneumonia

Features
Management

Question 6

Q

Pulmonary embolism

Features
Management

Question 7

Q

Acute pulmonary edema

Features
Management

Question 8

Q

List neuromuscular causes of respiratory failure

Answer

A

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

Question 9

Q

Causes of poor lung compliance

Answer

A

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

Question 10

Q

Causes of high airway resistance

Answer

A

Obstructive lung diseases:
- Asthma
- COPD
- Central airway obstruction
- emphysema
- Bronchospasm/ laryngospasm

Airway compression:
- upper airway inflammation
- mediastinal masses

Question 11

Q

Devices in ICU to assist breathing

Devices to avoid dry air induced airway inflammation

Answer

A

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)

Question 12

Q

Basic mechanical ventilator modes/ IPPV

Answer

A

Continuous Mandatory Ventilation (CMV)
Volume Control (VC)
Pressure Control (PC)
Synchronised Intermittent Mandatory Ventilation (SIMV)
Pressure Support (PS)

Question 13

Q

Compare volume control and pressure control ventilators

Advantages

Answer

A

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)

Question 14

Q

Mechanical ventilation/ PPV

Advantages
Indications

Answer

A

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

Question 15

Q

Indications and contraindications of non-invasive PPV

Question 16

Q

Modes of non-invasive ventilation (NIV)

Indications

Answer

A

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

Question 17

Q

Identify the type of mechanical ventilation shown here

Changes with which pathologies

Question 18

Q

Identify the type of mechanical ventilation shown here

Changes with which pathologies

Question 19

Q

Disadvantages of pressure control and volume control ventilators

Answer

A

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

Question 20

Q

Metrics set on ventilator

Answer

A

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