PRE-ANESTHETIC ROUTINE
1)
GENERAL
a)
A current weight must be
obtained and recorded on the patient’s anesthetic record.
b)
An Emergency Drug Reference Sheet should be immediately accessible
for all patients at all times.
i)
Some computer systems have an emergency drug component built into
the software. If so, a customized reference should be produced for, and
kept with, each patient. Alternatively, an emergency drug reference should
be immediately available in the event it should be needed. The AAHA
library has such a reference sheet if you do not have a current one.
c)
An Anesthetic Record should be prepared for each patient. A copy of
an example sheet is included at the end of this reference.
2)
PHYSICAL EXAMINATION
a)
A pre-anesthetic physical examination should be performed and the
information entered into the patient record
i)
This examination should be performed by a licensed technician or a
staff veterinarian. Each practice should develop their own guidelines as
to when the physical examination is to be performed by the doctor and when
it can be performed by the technician. Generally speaking, this interval
can be longer for younger pets exhibiting no health concerns and it should
be shorter when dealing with geriatric and unhealthy patients.
(1)
Some States may require this PE be performed by a DVM and may
stipulate the timing of this PE. Be familiar with your State requirements.
We cannot detail State to State variation in this reference.
b)
A final categorization of the patient should be made based upon the
following guidelines:
i)
Excellent - animal with no organic disease or in whom the
disease is localized and is causing no systemic disturbance.
(1)
example - healthy 3 year old neuter.
ii)
Good - animal with mild
systemic disturbance which may or may not be associated with the
planned procedure.
(1)
example - mildly anemic patient, obese patient, geriatric patient.
iii)
Fair - animal with moderate systemic disturbance which may or
may not be associated with the planned procedure and which usually
interferes with normal activity but is not incapacitating.
(1)
example - mitral valve insufficiency, moderate anemia.
iv)
Poor - animal with extreme systemic disturbances which are
incapacitating and are a constant threat to life and seriously interferes
with the animal’s normal function.
(1)
examples - uncompensated mitral valve insufficiency, severe
pneumothorax.
v)
Critical - animal presenting in a moribund condition, and is
not expected to survive 24 hours with or without surgery.
This implies that medical treatment cannot improve the animal’s
condition and that surgery is required immediately.
(1)
Example – acute, severe intra-abdominal hemorrhage.
3)
PRE-ANESTHETIC MEDICATIONS & FLUIDS
a)
Pre-anesthetic medication decisions should be discussed with a
staff veterinarian.
i)
Patients should be provided with an experience that minimizes their
stress and anxiety and minimizes their discomfort.
(1)
This not only makes their stay more pleasant; reducing stress and
anxiety is an important component in the analgesic process
ii)
The selection of these medications should be based on the
individual needs of the patient as discussed with one of the doctors.
(1)
Species, size, age, attitude, and health status should be factored
into this decision.
(2)
The safety of our staff and the importance of the planned procedure
are also important factors to be considered.
iii)
The timing of the administration of the pre-anesthetic meditation
is also an important consideration.
(1)
In general, the pre-anesthetic medications should be administered:
(a)
30 to 45 minutes prior to the induction of anesthesia if given
subcutaneously.
(b)
15 to 20 minutes prior to the induction of anesthesia if given
intramuscularly
(c)
It would be ideal to wait until the pre-anesthetic medications have
taken effect before placing the patient’s IV catheter.
b)
All syringes must be labeled as to their contents.
i)
Consider commercial stickers when available.
ii)
Use tape and marker as needed.
c)
It is preferable to have securely placed an intravenous catheter
prior to anesthetic induction.
i)
The catheter should normally remain in place until the animal is
recovered to a point that no further need for IV medication or fluid
support is anticipated.
ii)
Due to the fractious nature of some patients, it may be necessary
to place the catheter immediately after anesthetic induction and remove
the catheter prior to full anesthetic recovery in order to protect the
safety of the staff.
iii)
In feline patients, the medial femoral vein, just above the tarsus,
is an often overlooked site to place a peri-operative catheter.
(1)
This site is not as attractive for day to day IV fluid management.
d)
Pre-anesthetic fluids may be indicated for optimal patient support.
The timing and the length of the fluid administration should involve input
from a staff veterinarian.
i)
For general peri-operative fluid support:
(1)
5 ml/lb/hr (10 ml/kg/hr) is the suggested starting point.
(2)
10 ml/lb/hr (20 ml/kg/hr) is the upper limit for general fluid
support.
(3)
the individual needs of the patient may dramatically alter this
fluid rate.
(a)
A 5 ml/lb (10 ml/kg) bolus can be useful when Bp drops and needs to
be addressed more quickly. This may be repeated once.
ii)
IV fluids should be administered through an infusion pump whenever
available.
(1)
This is especially important for small patients and cardiac
patients for whom fluid overload is a much more likely complication.
(2)
If an infusion pump is not available, a micro-dripset should be
used when administering fluids to patients under 15 pounds or patients
requiring more control over fluid rates.
iii)
Fluid bag and drip set protocol.
(1)
Date all fluid bags and drip sets when first put into service.
(2)
Switch IV extension sets between patients.
(3)
Always cover the drip set end with a new sterile needle.
(4)
Discard fluid bags and drip sets over 1 week old.
(a)
Immediately discard any fluid bags that contain cloudy fluid or
those suspected to be contaminated.
(b)
Immediately discard any drip sets suspected to be contaminated.
(5)
A high visibility fluorescent orange label must be used to identify
any medications added to a fluid bag.
4)
PRE-ANESTHETIC TESTING
a)
Pre-anesthetic testing is a consideration to allow detection of
underlying disorders that may influence the management of the patient or
influence the prognosis associated with any given disorder. The decision
regarding when to perform preanesthetic tests and which tests to include
is a decision that needs to be addressed individually by each practice.
b)
There is considerable debate as to the extent and timing of such
testing.
c)
Blood samples should be drawn prior to premeds if it is not
excessively stressful to the patient as premeds may influence the results
of certain tests
i)
Example – Acepromazine can decrease patient PCV up to 30%
d)
If blood collection is not possible without premeds, or is too
stressful, then administer premeds, wait 15 to 20 minutes, then collect
samples
(1)
Make sure the laboratory results are labeled so as to indicate that
they were collected post-premeds if acepromazine has been used.
|
