Breathing Systems Flashcards
(35 cards)
Type of tubes used in Re-breathing system
Circle Universal F
Type of tubes used in non-rebreathing system
Mapleson A-F **Bain and Mapleson F most common
What are the anatomical dead spaces – areas that do not participate in gas exchange
Oral cavity, larynx, trachea, bronchi
What is mechanical dead space
portion of the circuit where bidirectional flow is occurring – rebreathing exhaled gases
Areas of mechanical dead space
Face mask
Endotracheal tube extending past incisors
Capnograph or other adapters
Y-piece
Advantages of Re-breathing system
Lower fresh gas flow rate required Patient has warm, humidified gases Saves money Decreases pullution
Disadvantages of re-breathing system
Higher resistance to breathing Gas concentration changes occur slowly More components –> more leak potential
Patient signs of CO2 absorbent exhaustion
Increased RR (compensating for more inspired CO2) Increased HR and BP (CO2 -> sympathetic stim) Red mucous membranes (vasodilation)
Equation to determine size of reservoir bag
Weight kg x 90 = mL **Convert to Liter
Size of bag used for horses
30 L bag or 20 L ventilator capacity
Small animal <50 kg Induction/Recovery O2 flow rate
50-100 mL/kg/min
Small animal <50 kg Maintenance O2 flow rate
20-50 mL/kg/min
Large animal induction/recovery O2 flow rate
20-50 mL/kg/min
Large animal maintenance O2 flow rate
10-20 mL/kg/min
Advantages of non-rebreathing system
Light, minimal dead space and resistance to ventilation, rapid changes in anesthetic gas, fewer components/leaks
What type of patient would use a non-rebreathing system
Under 3 kg
Disadvantages of non-rebreathing
High flow rates Cold/dry air More expensive More pollution
Flow rates for non-rebreathing
Must be high - 2-3x tidal volume (300 ml/kg/min)
What does a cuff on the ET tube do
Protects airway and environment
What patients would you not use a cuff for
very small or birds
What are the two types of cuffs and which is preferred
High volume - low pressure – Preferred
High pressure - low volume
What type of ET tube is this and what are its characteristics
Murphy
Can be cuffed or uncuffed
“Murphey eye” allows gas flow if end of tube is obstructed
**Most common tube
What ET tube is this and what are its features
Cole
Uncuffed
Commonly used on birds, has “shoulder” that seals against glottis
What ET tube is this and what are its characteristics
Wire Reinforced (armored)
Used to prevent collapse of tube lumen when patients are placed in extreme flexion
**Can’t be used for MRI due to metal
