Unit 1: ARF & ARDs Flashcards
Hypoxemia is defined as a PaO2 of <__ mm Hg.
PaO2 <80 mm Hg
Respiratory Failure is defined as a PaO2 <__ mmHg OR a PaCO2 of >__ mmHg
PaO2 <80 mmHg (book says <60 mmHg p. 593)
OR
PaCO2 of >45 mmHg
Acute Respiratory Failure (ARF) can be ______ failure, _____ failure, or a combo of both.
Ventilatory or Oxygenation/Perfusion (gas exchange) failure
What would indicate that Acute Respiratory Failure (ARF) is both a ventilatory and oxygenation failure?
An abnormal pH
Causes of Ventilation failure?
Problem with chest &/or lungs, Injury to respiratory control center, or Inability to control respiratory muscles
1. Chest trauma (rib fractures)
2. Drug Overdose
3. Pneumothorax
4. Pulmonary edema
5. Airway obstruction
6. Paralysis
7. Spinal cord injury
Causes of Oxygenation/Perfusion failure?
Poor lung blood flow
1. Pneumonia
2. PE
3. Hypovolemic Shock
Causes of BOTH Ventilation/Perfusion failure?
- COPD
- Asthma
- CF
- ARF
*Starts as a ventilation failure, but progresses to both
The S/S of ARF are r/t the systemic effects of ____, ____, and _____.
- Hypoxia
- Hypercapnia
- Acidosis
What is the hallmark finding for ARF?
Dyspnea
How do we evaluate/grade the intensity of the dyspnea r/t ARF?
How breathless the patient becomes while performing common tasks like talking, lying down (orthopnea) or on exertion.
Pulse oximetry (SpO2) can be used to evaluate ARF, but it’s not always accurate.
What should we assess instead for more accuracy?
End-tidal CO2 (ET-CO2)
The pulse ox may show an adequate SpO2 result, but also an increased ETCO2 indicating respiratory failure
(Also helps R/O a PE if the ETCO2 is >36)
What S/S would we see once hypoxia sets in r/t Acute Respiratory Failure (ARF)?
Alkalosis due to hyperventilation:
1. Restlessness, agitation, irritability
2. Confusion
3. Changes in LOC (hypercapnia)
What S/S would we see once hypoxemia sets in r/t Acute Respiratory Failure (ARF)?
Acidosis has set in:
1. Hypotension
2. Bradycardia
3. Weak pulses
Interventions for ARF:
- Treat underlying cause
- Oxygen
- Positioning (High-Fowlers)
- Anxiety Mx
- Energy-conserving measures
Acute Respiratory Distress Syndrome (ARDS) is Acute Respiratory Failure with:
- Persistent Hypoxemia even with 100% O2
(aka Refractory hypoxemia) - Decreased pulmonary compliance (fibrosis)
- Dyspnea
- Pulmonary edema (bilateral + non-cardiac-related)
- Diffuse pulmonary infiltrates (CXR = ground-glass)
ARDS often occurs after an ‘Acute Lung Injury’ (ALI) from a systemic inflammatory response caused by:
- Sepsis
- Pancreatitis
- Trauma
- Transfusions (TRALI)
What are two causes of ARDS that result from direct injury to the lungs?
- Aspiration
- Pneumonia
S/S of ARDS
- Increased work of breathing (that’s painful to watch)
- Loud breathing/lung sounds (washing machine)
- Cyanosis
- Accessory muscle use
- Confusion
Diagnostics for ARDS
- ABG
- CXR (ground glass appearance)
- Sputum culture (to R/O infection)
What types of continuous monitoring should we have going for a pt with ARDS?
- Cardiac monitoring
- SpO2
- ETCO2 if intubated
What is the P/F ratio? Normal range?
PaO2/FiO2 (the arterial O2 pressure vs the % of O2 were giving the patient)
>=400
What P/F ratio would indicate ARDS?
P/F ratio <300
Interventions for ARDS:
- Mechanical Ventilation/PEEP
- Sedation
- Paralytics
- Analgesics - Proning
- Mobility (depending on work needed to breathe)
- ECMO
What should we do prior to proning an ARDS pt?
- Obtain an ABG to establish a baseline
- Sedate
- Paralyze
What is PEEP? What does it promote?
Peak Expiratory End Pressure
”Recruiting” – allows gas exchange to occur (keeps the reserve volume left over following expiration oxygenated, making it easier to start ventilation sequence)
What about IV fluids?
it depends on the cause! Are they hypotensive?
What about nutrition?
Enteral nutrition (tube feeding/TPN)
