Unit 2: Acute Respiratory Failure Flashcards
Acute Respiratory Failure
when one or both of the gas exchange functions (oxygenation or ventilation/CO2 removal) of the lungs are compromised
-life-threatening/ high mortality
Gas Exchange Functions of the Lungs
- Oxygenation
- Ventilation/ CO2 removal
Compromise of the Gas exchange functions of the lungs leads to?
hypoxemia and/or hypercapnia/hypercarbia (increased PaCO2)
Types of Respiratory Failure
- Hypoxemic Respiratory Failure (Type I)
- Hypercapnic Respiratory Failure
Hypoxemic Respiratory Failure
-PaO2 less than 60 mmHg
Hypercapnic Respiratory Failure
- respiratory acidosis
- PaCO2 greater than 50 mmHg
- pH less than 7.35
Risk Factors for Hypoxemic Respiratory Failure (Type I)
include disease processes that produce a V/Q mismatch (ventilation/ perfusion) or impair oxygen diffusion at the alveolar level
- pneumonia
- pulmonary edema
- PE
Risk Factors for Hypercapnic Respiratory Failure (Type II)
include diseases that impair ventilation or cause hypoventilation
>seen in patients with impaired chest-wall movement and thus impaired ventilation
-acute asthma
-narcotic overdose
-peripheral nervous system disorders
Risk Factors for Acute Respiratory Failure
> Impaired Ventilation (Hypoventilation):
- airway obstruction
- respiratory muscle weakness/paralysis that can occur w/ neuromuscular disease (myasthenia gravis)
- chest-wall injury
- anesthesia
- opioid administration
> Ventilation-perfusion Mismatch (V/Q mismatch):
- COPD
- Restrictive lung diseases (pulmonary fibrosis)
- Atelectasis
- Pulmonary embolus (PE)
- Pneumothorax
- ARDS
> Impaired Diffusion (Alveolar):
- Pulmonary Edema
- ARDS
Early Clinical Manifestations of Acute Respiratory Failure
- dyspnea
- restlessness
- anxiety
- fatigue
- increased BP from baseline
- tachycardia
Intermediate Clinical Manifestations of Acute Respiratory Failure
- confusion
- lethargy (d/t increased CO2)
- pink skin coloration (d/t increased CO2)
Late Clinical Manifestations of Acute Respiratory Failure
- cyanosis
- coma
Laboratory and Diagnostic Tests
- ABGs
- Venous Oxygen Saturation
- Hemoglobin and Hematocrit
- Chest x-ray
- Sputum cultures
ABGs
assess oxygenation and ventilation in the lungs
- hypoxemic respiratory failure has an initial respiratory alkalosis d/t hyperventilation along w/ hypoxemia
- once initial blood gases analyzed and treatment initiated, pulse oximetry is used to monitor oxygenation ( SpO2 greater than 94%; PaO2 of 80 mmHg)
Hemoglobin and Hematocrit
- analyzed to make certain there is enough binding sites for oxygen to ensure adequate oxygen-carrying capacity
- RBCs carry oxygen to the cells for cellular oxygenation; if not sufficient RBCs, the oxygen carrying capacity of the blood is diminished
Chest X-ray
- show underlying pathology
ex: heart failure, pulmonary congestion, pneumonia, or pneumothorax
Sputum Culture
to r/o a pathogenic (i.e. bacterial or viral) cause of failure
Respiratory Failure
not a disease
- condition caused by another disease or disorder
- treat failure and underlying cause
Treatment for Acute Respiratory Failure
- begins w/ oxygen
- based on severity: start with Nasal cannula or Venturi Mask
- in acute respiratory failure, placed on nonrebreather mask w/ 100% FiO2
Treatment for Cases of severe V/Q mismatch
- Noninvasive positive-pressure ventilation (BIPAP or CPAP)
- Invasive positive-pressure ventilation: requires an advanced airway such as an endotracheal tube (ETT) and mechanical ventilation