Is Anesthesia Safe?
Authored by: Laura McLain Madsen DVM
anesthetize animals on a daily basis. At least once per week in any
clinic, a pet owner expresses concern about anesthesia: Is it safe? Will
my pet survive the procedure?
is very safe. The risk of a pet dying under anesthesia is less than
1%. The rare patients that are lost under anesthesia are generally
emergency surgeries, when the patient's condition is extremely critical.
The risk of a pet dying under anesthesia while undergoing a routine spay,
neuter, dental or mass removal is extremely low, but this risk can be
affected by the anesthetic drugs used and the monitoring of the patient.
you imagine an anesthesiologist in a human hospital using ether or chloroform
in the 21st century? Of course not. But, unfortunately (and
surprisingly), there are no standards of care for veterinary anesthesia, and
some clinics are still using out-of-date techniques. Here is a list of
questions to ask your veterinarian the next time your pet is scheduled for an
pre-anesthetic blood work run? All patients, not just the old or sick,
should have basic pre-anesthetic blood tests performed checking the blood
sugar, kidney values, and red blood cell count. Many animals will require
more extensive pre-anesthetic blood work. Even in animals under one year
old, blood work will occasionally detect abnormalities that could affect
intravenous fluids administered during anesthesia? Many drugs used for
general anesthesia tend to cause blood pressure to decrease. Intravenous
fluids will combat this decrease. In addition, if there are any adverse
reactions under anesthesia, an intravenous catheter allows immediate
administration of emergency drugs.
the pet's body temperature maintained during and after anesthesia? All
animals, especially cats and small dogs, lose a lot of body heat under
anesthesia. The resulting hypothermia can slow the anesthetic
recovery. Anesthetized pets should be placed on a recirculating warm
water pad and/or under a warm air blanket. Conventional heating pads are
risky because they can cause burns.
the pet intubated, and what anesthetic gas is used?
Intubation means that the patient has an endotracheal tube placed through the
mouth and into the trachea, through which gas anesthetic is administered.
The endotracheal tube allows controlled respirations if the patient is not
breathing well on his or her own, and prevents accidental inhalation of stomach
contents if the pet vomits under anesthesia. Virtually every surgical
procedure done in dogs and cats requires intubation and gas anesthesia.
The modern gas anesthetics are halothane, isoflurane and
sevoflurane. Methoxyflurane is out-of-date.
pain control is used? Surgery hurts! It doesn't matter if the
patient is a human, a dog, or a guinea pig. Analgesia is the relief of
pain, and in modern anesthetic protocols we strive for pre-emptive analgesia
(blocking the pain pathways before the painful procedure starts), and balanced
anesthesia (trying to block the pain pathways from as many directions as
monitoring techniques are used? It is critical to monitor the patient's
vitals while under anesthesia to ensure that the respiratory and cardiovascular
systems are functioning well, and to ensure that the patient is not under too
lightly or too deeply. Most important is that someone besides the surgeon
(who is occupied) is monitoring the heart rate, respiratory rate, and anesthetic
commonly used monitoring techniques include:
- An electrocardiogram (EKG) to monitor
the heart rhythm for arrhythmias.
- A pulse oximeter to monitor the
percentage oxygenation of the blood, which should be close to 100%.
- A machine to monitor the blood
- A machine (apnea monitor or
capnograph) to monitor the respiratory rate and carbon dioxide level.
concern many pet owners have is the cost of anesthesia: Why is it so
expensive? Why does Dr. X charge $300 for a dental while Dr. Y down the
street only charges $100? As you can see, modern anesthesia involves a
lot of equipment and expertise, and this unfortunately costs money.
Cutting corners by not intubating patients, not keeping patients warm, or
skimping on pain medications and monitoring can save money, but the price is
decreased comfort and safety for your pet.
Laura McLain Madsen, DVM
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