|Key Performance Indicators
for a veterinary surgery - spay of a Chihuahua
of a Chihuahua spayed by Dr Sing K Y
Sunday May 6, 2012
New client. A young lady with her parents from
North Singapore had booked me to spay their Chihuahua. Female, 8
months. Said to have heat 2 months ago. I noted that the vulva
was still swollen.
I used this case to mentor Dr Daniel so that
he could see how an experienced vet would handle a case in the
fastest, safest and most efficient way. Veterinary surgery text
on spays don't reveal the practical aspects of the real life and
death situation. He was to ask questions about the spay.
1.1 Inpatient record. General health check up
by Dr Daniel. Weight of dog: 1.7kg
1.2 The owner did not want blood test.
1.3 Clipping the surgical area outside
the Surgery Room.
1.4 Anaesthesia & surgical record. Dr
Daniel to calculate sedation dosage at 50% of the formula for
Domitor (0.034 ml) + Ketamine (0.043) IV and add equivalent
amount of 0.07 ml normal saline to make it 0.14 ml to be given
IV by me.
1.5 Absorbable suture packet 3/0 x 1 was
prepared. However, I used 2/0.
2. SURGERY ROOM
2.1 Sedation by m (Dr Sing K Y). Mr Min would hold
the dog and distended the left foreleg cephalic vein. He was
still not good at this despite his at least one year of
experience. Somehow, he did not press the right elbow skin area
and so the cephalic vein was not distended. I tried the IV but
found no blood drawn out. I asked him to twist the skin to the
side and the cepahlic vein was visible.
For some reasons, Mr Min can't distend the
cepahlic vein in some dogs but could do in others and today was
his bad day.
I knew the dog would not stay still long. So,
once I injected and saw the blood gushing inside the syringe,
the dog started withdrawing her left foreleg. I injected
immediately instead of waiting. There was no time to waste as
the full dosage to be given was just 50% of the calculated dose.
"The whole dosage might not be injected," I said to Dr Daniel as
the dog had withdrawn her leg as I completed the injection. It
was a wink of the eye. However, the dog quietened and dropped
her head. She was sedated within 60 seconds.
2.2 As 50%* of the formula is insufficient
sedation for intubation, I asked Mr Min to give isoflurane gas
at 5% for less than 60 seconds. It was around 40 seconds. I
intubated the dog. There was slight coughing but soon the dog
was anaesthesized and maintained on isoflurane at around 1%. Mr
Min was to record the % at 5-minute intervals.
(*At 100% of the formula, no isoflurane gas
would be necessary but I seldom use 100% as isoflurane gas is
much safer and the dog wakes up at the end of spay. Giving 100%
would delay waking up. Each procedure has its pros and cons).
2.3 Dog's belly shaved and cleaned.
2.4 Skin and linea alba incision. In this dog,
the umbilical scar was not distinct. So I made the incision a
bit further than the usual 1 cm from the scar. I showed how I
blunt dissected the subcutaneous fat in less than 2 seconds to
show the white fibrous linea alba. Many new vets took longer to
find the linea alba due to slow dissection and separation of the
fat. Sometimes, the new vet could not see the linea alba due to
the cloudiness of the SC fat masking the white line. A piece of
SC fat could be cut off if the dog was fat so that the linea
alba can be seen.
Then I had to extend cranially to expose the
left ovary as the ovary was leaning very close to the cranial
edge of the incision without giving me access to the ovarian
ligament. "The left ovary is more cranial than the left," I said
to Dr Daniel. "I have to extend the incision to expose the whole
ovary and the ovarian ligament."
QUESTION. "You didn't break the ovarian
ligament of the left ovary," Dr Daniel said as I extended the
incision of the linea alba cranially by 3 mm and could ligate
REPLY. "There is no need to break the ovarian
ligament in the Chihuahua if the left ovary is well exposed," I
said. "You will note that the right ovary is easily exposed as
it is more caudal and I did not need to cut or rupture the
ovarian ligament. However, in larger breeds and with small
incision, the ovarian ligament can be stretched and cut before
ligation of the ligament."
3. The uterine body was ligated once.
4. Linea alba closed with 3 interrupted
5. Skin incision (2 cm long) was closed with 2
horizontal mattress sutures.
6. No bleeding but the ovaries and uterine
bodies were swollen and red, indicating heat was still present.
There was some bleeding of the surrounding tissues due to the
dog being on heat.
7. Post-op tolfedine and baytril SC. 4 days of
tolfedine. One bottle of trimethoprim and one bottle of
multi-vitamin. E-collar and bandage of wound.
8. Dog woke up just as I completed the last
stitch as I had asked Mr Min to switch off the isoflurane 1
minute as I stitched the skin.
SUGGESTION. "It is better not to switch off
the isoflurane and disconnect in case of emergency," Dr Daniel
ANSWER. "Based on the smooth anaesthesia, such
happening is unlikely. However, the endotracheal tube is still
inside the dog if there is an emergency." In any emergency,
there will be cardiac massage first, in my experience, rather
POST-OP. The Chihuahua got up without crying
within 2 minutes of completion of stitching. This meant I don't
need to give Antisedan antidote to reverse Domitor. The surgery
took a longer time as I had to extend the cut cranially and to
hook out the left uterine horn. In this case, after 6 tries and
hooking up the small intestine, I switched to hooking out the
right uterine horn and was successful. This delay added up to
several seconds. Normally, I could hook out the left uterine
horn in 3 attempts. But veterinary surgery is full of surprises.
THE ANAESTHESIA AND SURGICAL RECORD
Healthy, young, 10kg 0.4
ml 0.5 ml
Healthy, young, 1.7kg 0.068 ml
0.034 ml 0.043 ml
Actual given 0.03 ml + 0.04 ml = 0.07 ml. Add
0.07 ml normal saline. Total IV = 0.14
KEY PERFORMANCE INDICATORS
A: Injection of induction drugs: 10.45 am
B: Isoflurane first given: 10.46 am.
C: Isoflurane gas stopped: 11.15 am
D: First skin incision: 10.54am
E: Skin stitching completed: 11.17 am
E-A = 33 minutes
E-D = 23 minutes
C-B = 29 minutes
BENCHMARKING SPAY PROCEDURE
The Chihuahua spay surgery by an experienced vet with 40 years
of spay experience like me took around 23 minutes in this
Chihhuahua. It could be as short as 15 minutes but I don't
expect younger vets to achieve this benchmark. However, one hour
is too long.
TIP: "The hydraulic operating table
must be adjusted to the proper height for the vet to operate
comfortably and efficiently," I said to Dr Daniel. Each vet has
his or her own height and so it is best not to bend double by
not making full use of the hydraulics of Toa Payoh Vets'
operating table in long surgeries like spay.
QUESTION: "How is it possible for a spayed dog
to bleed on heat when she is spayed?" Dr Daniel asked me
when I said that there are complaints of dogs and cats still
cycling with heat when they have been spayed. "Usually there is
a bit of ovarian tissue left behind," I explained that the left
ovary is more cranial. So, a vet may incise a bit of ovarian
tissue after ligation of the ovarian ligament. The prevention is
to make a bigger linea alba incision to expose the whole ovary
and ligament. This means making a big skin cut which cannot be
helped. Owners are unhappy when spayed dogs and cats come on
heat staining the floor with blood and with cats, continuous
caterwauling can drive the owner crazy as evident in one case of
a spayed cat.
A spay is not that simple after all. Besides being on heat,
there are reported cases of stump pyometra. I encountered one
such case of a dog spayed by Vet 1, in the last 40 years of
practice and that would be due to remnant of ovarian tissues
left during spays.
All veterinary surgeries will adopt a
consistent process and approach as described in this case study.
I will be doing my trust and audit of some veterinary surgeries
done by my associate vets.
In the April 20, 2012, AVA Veterinary Clinic inspection of Toa
Payoh Vets, the letter of the annual renewal of the licence
mentioned that the clinic was well managed. I intend to ensure
that it will be well managed with the trust and audit
procedures. It will always be difficult to effect changes for
the better and this needs time and explanation.