Acute Respiratory Failure

Question 1

Pulse oximetry

Answer 1

Measures amount of hemoglobin that is bound to oxygen (saturation percentage)

Normal is 94% or better

Goal in respiratory distress/failure is to get pulse ox at 90% of better

Question 2

Oxygen delivery ways

Answer 2

Nasal cannula

• adult flow rates are between 1-6L
• adding 1 liter increases FIO2 by 4%, starting at 21% (i.e 4L of room air oxygen = 21+ 16 = 37%)
• use for mildly hypoxic

Non-rebreather mask

• used usually if patients oxy sat rates don’t increase to stable levels after 6L
• FIO2 is approximately 70% with this bag (varies based on seal of the bag)

Question 3

Respiratory failure

Answer 3

Defined as inadequate gas exchange due to malfunction of one or more components of respiratory system

Two main types

1) hypoxemia
2) hypercapnic
* note a patient can have both simultaneously*

Signs/symptoms

• mental altered status
• extreme fatigue
• Cyanosis
• bad ABG values
• accessory muscle use and supraclavicular retraction

Question 4

Hypoxemia respiratory failure

Answer 4

ABG saturation of less than 90% while received ing increased inspired oxygen

Caused by Impaired alveolar diffusion via inflammation or fibrosis development along the alveolar membrane

Causes = pneumonia, ARDS, PE, pulmonary edema, alveolar hemorrhage

Treatment:

• treat underlying issue
• increase oxygen given (both total Liters and type of device)
• CPAP and BiPAP is most common
• endotracheal tube is required if they cant breath on their own due to altered mental status/constant vomiting, GCS <8 or complete apnea is seen.

Question 5

Hypercapnic respiratory failure

Answer 5

Unable to ventilate alveoli
- PaCO2 will be > 45mmHg

Results in respiratory acidosis
- every increase in 10 with PaCO2, pH will decrease by 0,08 (vise verse in alkalosis)

Causes =

• Drug OD
• obstructive COPD
• aspiration of foreign bodies
• neuromuscular diseases (MS and muscular dystrophy are most common)
• flail chest
• strokes