Flashcards in Chpt. 4 - Tech Notes Deck (16):
How long should an ET tube be?
The ET tube should be no longer than the distance between the most rostral aspect of the mouth and the thoracic inlet.
If longer, there is a risk that only one lung will be infused with oxygen and anesthetic gas or that mechanical dead space will be increased, leading to hypoxemia.
What needs to be checked at the beginning of the day?
Check both primary and secondary oxygen supplies at the beginning of the day to be sure they are turned on.
A failure to do this may result in a patient not receiving oxygen, a dangerous error that if not recognized may be fatal!
When handling compressed gas cylinders:
*Avoid contact with flames, sparks, or other sources of ignition.
*Turn the tank on only when it is attached to a yoke or pressure regulator.
*Store tanks only attached to a yoke, secured in a cart designed for this purpose, or chained to the wall.
*Never attempt to attach a tank to a yoke that does not fit, and never tamper with the safety system on a tank, line, or pressure-reducing valve.
How to calculate the oxygen volume in a compressed gas cylinder!
The volume in liters (L) of oxygen present in a compressed gas cylinder can be calculated by multiplying the pressure (in psi) in an E tank by 0.3 or by multiplying the pressure in an H tank by 3.
How to turn off a flow meter!
When turning off a flow meter, turn clockwise just until the ball or rotor drops to 0 L/min. Even though the knob can still be turned, do not turn it any further to the right or you will damage the valve!
What must be checked before each procedure?
Vaporizers must be checked before each procedure to make sure the liquid anesthetic level is between the upper and lower lines of the indicator window. The vaporizer should be refilled as needed but should be kept at least half full at all times.
What should you do, if a bottle of liquid inhalant anesthetic accidently breaks?
Vacate the room immediately and allow the room to air out until the anesthetic is completely evaporated and evacuated from the room.
What must be reattached after use of a non-rebreathing circuit?
The connector of the rebreathing circuit must be reattached to the outlet port or common gas outlet before the next patient is anesthetized.
A failure to do this results in an inability to keep the patient anesthetized and exposure of personnel to anesthetic gas.
What happens to the pop-off valve during manual ventilation?
The pop-off valve is closed before the bag is pressed when manually ventilating a patient.
Between each breath, the pop-off valve MUST be opened again to allow the escape of gases.
How full should the bag be at peak expiration?
During any procedure the bag should be approximately three fourths full at peak expiration.
Signs that CO2 granules must be changed:
*Hard, brittle granules
*Granules that are slightly off-white in color
*Color change of one half to one third of the granules
*A carbon dioxide (CO2) level greater than 0 during peak inspiration as measured with a capnograph
*Granules should always be changed after 6 to 8 hours of use
Maximum safe pressure manometer readings (when the chest is closed):
* 0 to 2 cm H2O when the patient is breathing spontaneously
* 20 cm H2O in small animals when positive-pressure ventilation is provided
* 40 cm H2O in large animals when positive-pressure ventilation is provided
Tube size differences
Standard small animal tubes are used on small animal machines for patients over 7 kg body weight.
Pediatric tubes are recommended for patients weighing 2.5 to 7 kg, to reduce mechanical dead space.
Large animal tubes are designed for use only on large animal machines.
What choice is based on patient body weight?
The appropriate choice of a machine (large animal versus small animal), reservoir bag, breathing tubes, oxygen flow rates, and breathing circuit type is based on patient body weight.
Why and how do flow rates vary?
With semiclosed rebreathing systems, flow rates vary from relatively low when maintaining a patient at a desired anesthetic depth to relatively high during induction and recovery and when changing anesthetic depth. This is because higher flows cause the patient's anesthetic depth to change more quickly.