Cyndi - Week 11 - Exam 5 Flashcards
what are the 4 characteristics of alveolar gas exchange?
- 1 cell thick alveolar wall
- thin film of moisture
- blood capillary
- oxyhemoglobin
what is respiratory failure?
- not a disease
* *due to underly8ing acute or chronic disease
what is hypoxemic failure?
- PO2 < 60 with FIO2 60% or more
- O2 doesn’t diffuse into blood from lungs
- At a PO2 of 60, hgb starts to release all its O2 molecles, placing the pt in a state of severe hypoxemmia
- *ex: HF, PE, asthma, pulmonary edema
what is hypercapnic failure?
CO2 > 45, with a pH <7.35
• PaCO2 doesn’t diffuse out of blood into lungs
• Inadequate ventilation or any cause of obstructed gas exchange can cause hypercapnia
• Examples: COPD, chest muscle paralysis, opiate toxicity
what is oxygenation failure? (hypoxemic respiratory failure)
Inadequate O2 transfer between alveoli and capillary
• Decreased PaO2 (<60 mmHg) onABG
• Decreased SaO2 with peripheral check
hypoxemic repiratory failure: hypoxemic failure may occur to what four factors?
- ventilation - perfusion mismatch (not 1:1)
- shunt - respiratory shunt
- diffusion limitation - alveolar capillary membrane
- hypoventilation
what is the main problem with hypercapnic respiratory failure?
ventilation failure
what is ventilation failure?
Inadequate CO2 diffusion between capillary and alveoli
• Insufficient CO2 removal
• Increased PaCO2
what are the possible reasons for hypercapnic/ventilation failure?
- Airways and alveoli (ARDS, asthma, COPD)
- CNS ‐ decreased drive to breathe
- Chest wall abnormalities – fracture, obesity
- Neuromuscular conditions
- Respiratory muscle weakness, paralysis
what is the direct acute lung injury?
- aspiration
what is the indirect acute lung injury?
- ARDS
what are the diagnostic tests for respiratory failure?
- ABGs and labs ‐ CBC, lytes, D‐dimer, sputum cultures
- End tidal (ET) CO2 monitoring – aka capnography
- EKG
- Hemodynamic monitoring (Arterial lines, central venous pressure, Swanz‐Gantz catheter)
- SVO2 monitoring – mixed venous
what radiologic tests will be used for respiratory failure?
- CT chest
- Chest X‐ray
- V/Q scan
what are the early sxs of respiratory failure (distress)?
- Δ LOC, restlessness, confusion, agitation
- Dyspnea, tachypnea,
- Nasal flaring, accessory muscle use
- Tripod position, pursed lip breathing
- Fatigue, cool clammy skin
- Tachycardia, HTN, dysrhythmias
what are the late sxs of respiratory failure (failure)?
- Cyanosis
- Paradoxical breathing, bradypnea, apnea
- PaO2 less than 45
- Hypotension
- Comas, tremors, seizures
what is acute respiratory distress?
sudden onset without previous problem
• ex: smoke inhalation
what is chronic respiratory distress?
have respiratory disease normally
• Example ‐ COPD ‐ Live at the edge of chronic respiratory insufficiency
what is acute on chronic respiratory distress?
Sudden worsening of chronic situation
• COPD or asthma exacerbation