Lecture 15: Respiratory failure Flashcards
1
Q
Arterial Hypoxemia
A
- PaO2 Ventilation/ ’V/Q disturbance’
Causes of hypoxemia
- Decreased or inadequate FiO2
- Decreased VA
- V/Q mismatch
- Shunt
In presence of an increased PaCO2, need to calculate A-a gradient; only increased in:
- V/Q mismatch
- Shunt
2
Q
Hypoxemia in the Presence of Parenchymal Disease on Chest Radiograph
A
- Extensive airspace disease
- Intrapulmonary shunt
- Severe Hypoxemia
3
Q
Hypoxemia in the Absence of Parenchymal Disease on Chest Radiograph
A
- VA/Q mismatch: Airway disease
- Example: Acute asthma
- Test: Spirometry shows obstruction
4
Q
Arterial Hypercapnia
A
PaCO2 production / ventilation
5
Q
Failure of the ‘Ventilatory Pump’
A
- Disease involving the extrapulmonary compartment
- Impaired alveolar ventilation
- Associated respiratory acidosis
- Hypercapnia ± hypoxemia
6
Q
Acute Lung Injury
A
Syndrome of acute and persistent lung inflammation with increased vascular permeability
3 clinical features:
- widespread, bilateral radiographic infiltrates
- PaO2/FiO2 ratio of less than or equal to 300 mmHg, regardless of the level of PEEP
- no clinical evidence for an elevated left atrial pressure
7
Q
ARDS: Pathophysiology
A
Pmv most affected
8
Q
Cardiogenic pulmonary edema
A
Pmv most affected
9
Q
Non-cardiogenic pulmonary edema
A
K most affected
10
Q
Direct lung injury
A
- Pneumonia
- Aspiration of gastric
- contents
- Pulmonary contusion
- Fat emboli
- Near-drowning
- Inhalational injury
- Reperfusion injury
11
Q
Indirect lung injury
A
- Sepsis
- Severe trauma with shock and burns
- Cardiopulmonary bypass
- Drug overdose
- Acute pancreatitis
- Massive transfusion of blood products
12
Q
Acute Respiratory Failure in COPD
A
Problem
- Increased airways obstruction
- VA/Q mismatch
- Hypoxemia and hypercarbia with respiratory acidosis
- Hyperinflation with respiratory muscle dysfunction
- Pulmonary hypertension
Tx Principle
- Bronchodilation
- Oxygen
- Oxygen and ↑Ventilation (spont or artificial)
- Deflation by use of bronchodilators
- ↑pO2 and ↓pCO2
