VETERINARY ANESTHESIA
CHECKLIST SET-UP
Printable version
• Gas Supply: Using tank
wrench, turn knob on E
tank(S) counter-clockwise
and check pressure. (NOTE: A
full oxygen tank will
register approximately 2000
PSI and a nitrous oxide tank
will register approximately
750 PSI.)
• When the pressure gauge
registers lower than 200
PSI, the tank should be
replaced with a full tank.
If using a local source,
(e.g., a G tank or central
supply,) connect machine to
outlet and check to make
sure the attachment is
secure.
• Connect breathing bag*
and breathing circuit** to
machine.
• Turn on flowmeter(s) to
check that the gas supply is
operational. Return
flowmeter(s) to the off
position, (finger tight
only, over tightening knob
will damage flowmeter
valve.)
• Pressure check circuit
by closing the pressure
relief valve and place thumb
over the patient connection
of the Y-piece. Activate
flush valve to fill system
to a level of 20cm of H2O
registered on the circuit
pressure gauge. Hold in this
position a few seconds and
if there are no leaks, the
pressure will hold steady.
However, if the pressure
stabilizes at the 20 cm H2O
setting. (This will
determine the magnitude of
leak and if more than 300
ml/min, an indication the
leak(s) must be fixed.)
• Place hand over all
connections, the breathing
circuit, and bag while
system is pressurized, and
feel for leaks. (For hard to
find problems, wet hand or
use soapy water solution
over connections. Evidence
of bubbles will help locate
leaks.)
COMMON PLACES FOR LEAKS
• Breathing bag and/or
breathing circuit
• Breathing Circuit point of
connection to machine
• Unidirectional breathing
valves
• CO2 absorber gaskets
• Pressure relief valve
• Vaporizer inlet and outlet
connections; filler cap
• Fresh gas delivery hose
and connection to machine.
CARBON DIOXIDE ABSORBER
• Absorbent must be
changed weekly. Select a day
of the week for this to be
routinely done.
• Refer to the absorber
canister decal for absorbent
volume. The usable volume of
absorbent should be not less
than 105 times the tidal
volume, which is estimated
to be 5ml/lb.,therefore a
1000ml absorber filled fresh
absorbent will function
properly for an animal up to
about 100lbs. (As the
absorbent is depleted,
available chemicals will
decrease as CO2 in converted
to HCO3. If half of the
absorbent in the center has
changed color, it is prudent
to refill the canister
especially if the unit is to
be used for a 100lb patient
or larger.)
• Moisture content of
absorbent must be maintained
once package is opened.
(Water is essential for the
chemical reaction to take
place and will be lost if
the machine is not used or
if opened packages of
absorbent are not properly
resealed.)
BREATHING VALVES
• Should be cleaned
periodically with a clean
cloth to remove accumulated
water vapor. (The exhalation
valve may stick in the open
position and lead to
re-breathing of CO2.)
BREATHING BAG
• Bag size is governed by
being able to fully expand
the lungs with bag
compression. A smaller bag
will better register
respiratory movement during
spontaneous breathing in
small patients as compared
to using a large bag. In
general, use small bags for
small patients and large
bags for large patients.
PATIENT WEIGHT
|
BAG SIZE |
15 LBS. OR LESS |
1/2 LITER |
15-30 LBS. |
1 LITER |
30-60 LBS. |
2 LITER |
60-100 LBS. |
3 LITER |
100 + LBS. |
5 LITER |
**BREATHING
CIRCUIT** |
Patients less
than 10 lbs. |
Semi-open system
(e.g., Bain, Ayres T
Circuits) |
Patients more
than 10 lbs. |
Semi-closed
circle *CO2
absorption system |
• Pediatric breathing hoses
are recommended for patients
less than 50lbs. When using
a circle system. For larger
patients, adult breathing
hoses may be used.
FLOW RATES FOR BREATHING
CIRCUITS
SEMI-OPEN SYSTEM:
Minimum flow rate should be
300 ml/min. for patients
3lbs. or less. Maintenance
flow rate is 100ml/lb. for
patients with a normal
breathing rate (avg. 30
breaths/min.) Flow rate must
be increased to 1 liter/min.
If breathing rate is more
than 50 breaths/min.
FLOW RATE
FOR SEM-OPEN SYSTEM |
5 lbs. or less |
100 ml/lb.* |
Normal 30
breaths/ min |
100 ml/lb. |
Normal >50
breaths/ min |
1 liter/ minute |
• Less then 3lbs. :
300ml/minute
SEMI-CLOSED
SYSTEM: Guideline
for maintenance flow rate is
800ml/minute for patients up
to 50lbs. Add 100ml/minute
for each 10lbs. up to
100lbs. Flow rate during
induction* is double that
used for maintenance.
FLOW RATES FOR
SEMI-CLOSED SYSTEM |
Patient Size |
Induction * |
Maintenance |
< 50 lbs. |
1 liter/minute |
500 ml/minute |
60 lbs. |
1.2 liter/minute |
600 ml/minute |
70 lbs. |
1.4 liter/minute |
700 ml/minute |
80 lbs. |
1.6 liter/minute |
800 ml/minute |
90 lbs. |
1.8 liter/minute |
900 ml/minute |
100 lbs. |
2.0 liter/minute |
1 liter/minute |
125 lbs. |
2.5 liter/minute |
1.25 liters/minute |
150 lbs. |
3.0 liter/minute |
1.50
liters/minute |
• Induction of anesthesia
is the initial delivery of
inhalant following
endotracheal intubation
until loss of the palpebral
reflex.