Respiratory FailureAbdul-Aziz Ontok, Fritzie Rasonable, April Suzette Exile
TOPIC OUTLINE Definition Epidemiology Classification Approach to the Patient with
Respiratory Failure Clinical Evaluation by Physiologic
Principles Specific Respiratory Failure Syndromes Mechanical Ventilation
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
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
CLASSIFICATION
1. By Pathophysiologic Derrangement
2. By its Acuity
3. By Physiologic Deficit
Pathophysio. Derangement Type I – alveolar floodingoPulmonary edema• Heart failure• Intravascular volume overload• Acute lung injury
ARDSoPneumoniaoAlveolar hemorrhage
Pathophysio. Derangement Type I – alveolar flooding Type II – alveolar hypoventilationo Impaired CNS drive to breatheo Impaired strength of neuromuscular
function in the respiratory systemo Increased loads on the respiratory
system
Pathophysio. Derangement Type I – alveolar flooding Type II – alveolar hypoventilationo Impaired CNS drive to breathe• Drug overdose• Sleep-disordered breathing• Hypothyroidism
Pathophysio. Derangement Type I – alveolar flooding Type II – alveolar hypoventilationo Impaired CNS drive to breatheo Impaired strength of neuromuscular
function in the respiratory system• Impaired neuromuscular transmission
MG, Guillain-Barre Sx, Phrenic nerve injury
• Respiratory muscle weaknessElectrolyte derangements
Pathophysio. Derangement Type I – alveolar flooding Type II – alveolar hypoventilationo Impaired CNS drive to breatheo Impaired strength of neuromuscular
function in the respiratory systemo Increased loads on the resp. system• Resistive loads – bronchospasm• Reduced lung compliance – atelectasis• Reduced wall compliance - pneumothorax• Increased minute vent. req. – embolus
Pathophysio. Derangement Type I – alveolar flooding Type II – alveolar hypoventilation Type III – lung atelectasis in the
perioperative period
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
CLASSIFICATION
1. By Pathophysiologic Derrangement
2. By its Acuity
3. By Physiologic Deficit
Acuity Acute Respiratory Failureo sudden, catastrophic event leads to life-
threatening respiratory insufficiency Chronic Respiratory Failureo gradual worsening of respiratory
function that leads to progressive impairment of gas exchange
ometabolic effects are partially compensated by adaptations in other systems
CLASSIFICATION
1. By Pathophysiologic Derrangement
2. By its Acuity
3. By Physiologic Deficit
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
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
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
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
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
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
APPROACH TO THE PATIENT1. 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
APPROACH TO THE PATIENT2. Measurement of respiratory rate3. Observation of the depth and pattern of
respiration simultaneously note signs of respiratory
distress: alar flaringpursed-lip breathinguse of accessory muscles
4. Palpation and Auscultation over each hemithorax
APPROACH TO THE PATIENT5. 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
6. 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
CLINICAL EVALUATIONDYSFUNCTION TEST FINDINGS IN DYSFUNCTION
Controller Respiratory rate <12/min in presence of hypoxia or hypercarbia and acidemia
CLINICAL EVALUATIONDYSFUNCTION 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
CLINICAL EVALUATIONDYSFUNCTION 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 motionsVC < 10 mL/kgIF < -20 cm water
Airway Auscultation Presence of wheezing or rhonchi
CLINICAL EVALUATIONDYSFUNCTION 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 motionsVC < 10 mL/kgIF < -20 cm water
Airway Auscultation Presence of wheezing or rhonchi
Alveolar Chest XR Alveolar infiltrates
CLINICAL EVALUATIONDYSFUNCTION 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 motionsVC < 10 mL/kgIF < -20 cm water
Airway Auscultation Presence of wheezing or rhonchi
Alveolar Chest XR Alveolar infiltrates
Pulm. Vascular JVP, ECG JVD, RBBB