1. Respiratory Failure
Abdul-Aziz Ontok, Fritzie Rasonable, April Suzette Exile

2. TOPIC OUTLINE Definition Epidemiology Classification
Approach to the Patient with Respiratory Failure
Clinical Evaluation by Physiologic Principles
Specific Respiratory Failure Syndromes
Mechanical Ventilation

3. DEFINITION
Failure of gas exchange due to inadequate function of one or more essential components of the respiratory system
Manifest as:
Hypoxemia – PO2 <60 mmHg (↓ O2)
Hypercarbia – PCO2 >45 mmHg (↑ CO2)
Combination of the two*
As respiratory demand exceeds functional capacity of the respiratory system, respiratory failure evolves

4. EPIDEMIOLOGY Common diagnosis among patients in ICU
Associated with poor prognosis
137:100,000 ind. or 360,000/year (U.S.)
36% of these individuals fail to survive
Incidence and Mortality increase with age and presence of co-morbid conditions

5. CLASSIFICATION By Pathophysiologic Derrangement By its Acuity
By Physiologic Deficit

6. Pathophysio. Derangement
Type I – alveolar flooding
Pulmonary edema
Heart failure
Intravascular volume overload
Acute lung injury
ARDS
Pneumonia
Alveolar hemorrhage

7. Pathophysio. Derangement
Type I – alveolar flooding
Type II – alveolar hypoventilation
Impaired CNS drive to breathe
Impaired strength of neuromuscular function in the respiratory system
Increased loads on the respiratory system

8. Pathophysio. Derangement
Type I – alveolar flooding
Type II – alveolar hypoventilation
Impaired CNS drive to breathe
Drug overdose
Sleep-disordered breathing
Hypothyroidism

9. Pathophysio. Derangement
Type I – alveolar flooding
Type II – alveolar hypoventilation
Impaired CNS drive to breathe
Impaired strength of neuromuscular function in the respiratory system
Impaired neuromuscular transmission
MG, Guillain-Barre Sx, Phrenic nerve injury
Respiratory muscle weakness
Electrolyte derangements

10. Pathophysio. Derangement
Type I – alveolar flooding
Type II – alveolar hypoventilation
Impaired CNS drive to breathe
Impaired strength of neuromuscular function in the respiratory system
Increased loads on the resp. system
Resistive loads – bronchospasm
Reduced lung compliance – atelectasis
Reduced wall compliance - pneumothorax
Increased minute vent. req. – embolus

11. Pathophysio. Derangement
Type I – alveolar flooding
Type II – alveolar hypoventilation
Type III – lung atelectasis in the
perioperative period

12. Pathophysio. Derangement
Type I – alveolar flooding
Type II – alveolar hypoventilation
Type III – lung atelectasis in the
perioperative period
Type IV – hypoperfusion of respiratory
muscles in patients in shock

13. CLASSIFICATION By Pathophysiologic Derrangement By its Acuity
By Physiologic Deficit

14. Acuity Acute Respiratory Failure
sudden, catastrophic event leads to life-threatening respiratory insufficiency
Chronic Respiratory Failure
gradual worsening of respiratory function that leads to progressive impairment of gas exchange
metabolic effects are partially compensated by adaptations in other systems

15. CLASSIFICATION By Pathophysiologic Derrangement By its Acuity
By Physiologic Deficit

16. Physiologic Deficit Nervous System – controller dysfunction
Musculature – pump dysfunction
Airways – airway dysfunction
Alveolar Units – alveolar dysfunction
Vasculature – pulm. vascular dysfunction
Failure of any one of these components can lead to respiratory failure

17. Physiologic Deficit Nervous System – controller dysfunction
Sedative medications
Chronic obstructive lung disease
Hypothermia post operatively
Brainstem stroke
Musculature – pump dysfunction
Airways – airway dysfunction
Alveolar Units – alveolar dysfunction
Vasculature – pulm. vascular dysfunction

18. Physiologic Deficit Nervous System – controller dysfunction
Musculature – pump dysfunction
Botulism
Myasthenia Gravis
Guillain-Barre syndrome
Postoperative pain
Airways – airway dysfunction
Alveolar Units – alveolar dysfunction
Vasculature – pulm. vascular dysfunction

19. Physiologic Deficit Nervous System – controller dysfunction
Musculature – pump dysfunction
Airways – airway dysfunction
Asthma
Emphysema
Bronchitis
Endobronchial mass/stricture
Alveolar Units – alveolar dysfunction
Vasculature – pulm. vascular dysfunction

20. Physiologic Deficit Nervous System – controller dysfunction
Musculature – pump dysfunction
Airways – airway dysfunction
Alveolar Units – alveolar dysfunction
Pneumonia
Pulmonary edema
Pulmonary hemorrhage
ARDS
Vasculature – pulm. vascular dysfunction

21. Physiologic Deficit Nervous System – controller dysfunction
Musculature – pump dysfunction
Airways – airway dysfunction
Alveolar Units – alveolar dysfunction
Vasculature – pulm. vascular dysfunction
Acute pulmonary embolus
Pulmonary hypertension
Arteriovenous malformation

22. APPROACH TO THE PATIENT
Determination of upper airway patency
Unconscious (occlusion of the tongue)
Head tilt-chin lift maneuver
Unable to dislodge foreign object
Subdiaphragmatic thrust
Suction secretions/vomitus
Secure airway with endotracheal tube if necessary
Perform tracheostomy/cricothyroidotomy if airway cannot be secured with ETT

23. APPROACH TO THE PATIENT
Measurement of respiratory rate
Observation of the depth and pattern of respiration
simultaneously note signs of respiratory distress:
alar flaring
pursed-lip breathing
use of accessory muscles
Palpation and Auscultation over each hemithorax

24. APPROACH TO THE PATIENT
Supplement findings with ABG measurement
Oximetry provides rapid way to determine blood oxygen content but does not provide information regarding alveolar ventilation and PCO2; do ABG
Implement initial therapy before specific etiology is diagnosed and treated
Supplemental oxygen might be all that is needed
Artificial ventilation if patient is in distress

25. FINDINGS IN DYSFUNCTION
CLINICAL EVALUATION
DYSFUNCTION
TEST
FINDINGS IN DYSFUNCTION
Controller
Respiratory rate
<12/min in presence of hypoxia or hypercarbia and acidemia

26. FINDINGS IN DYSFUNCTION
CLINICAL EVALUATION
DYSFUNCTION
TEST
FINDINGS IN DYSFUNCTION
Controller
Respiratory rate
<12/min in presence of hypoxia or hypercarbia and acidemia
Pump
Inspection, Vital Capacity, Inspiratory Force
Presence of paradoxical respiratory motions VC < 10 mL/kg IF < -20 cm water

27. FINDINGS IN DYSFUNCTION
CLINICAL EVALUATION
DYSFUNCTION
TEST
FINDINGS IN DYSFUNCTION
Controller
Respiratory rate
<12/min in presence of hypoxia or hypercarbia and acidemia
Pump
Inspection, Vital Capacity, Inspiratory Force
Presence of paradoxical respiratory motions VC < 10 mL/kg IF < -20 cm water
Airway
Auscultation
Presence of wheezing or rhonchi

28. FINDINGS IN DYSFUNCTION
CLINICAL EVALUATION
DYSFUNCTION
TEST
FINDINGS IN DYSFUNCTION
Controller
Respiratory rate
<12/min in presence of hypoxia or hypercarbia and acidemia
Pump
Inspection, Vital Capacity, Inspiratory Force
Presence of paradoxical respiratory motions VC < 10 mL/kg IF < -20 cm water
Airway
Auscultation
Presence of wheezing or rhonchi
Alveolar
Chest XR
Alveolar infiltrates

29. FINDINGS IN DYSFUNCTION
CLINICAL EVALUATION
DYSFUNCTION
TEST
FINDINGS IN DYSFUNCTION
Controller
Respiratory rate
<12/min in presence of hypoxia or hypercarbia and acidemia
Pump
Inspection, Vital Capacity, Inspiratory Force
Presence of paradoxical respiratory motions VC < 10 mL/kg IF < -20 cm water
Airway
Auscultation
Presence of wheezing or rhonchi
Alveolar
Chest XR
Alveolar infiltrates
Pulm. Vascular
JVP, ECG
JVD, RBBB