VET TECH PREP (Anesthesia)

The veterinarian asks you use glycopyrrolate to premedicate a patient in the hospital. Using the image, calculate how many milliliters you will administer to a 35 kg dog at a dosage of 0.01 mg/kg?

1.75 ml explanation -

You are monitoring an adult cat under anesthesia. Since induction, the heart has been slowing down. What is the approximate lowest acceptable heart rate for this cat?

120 explanation - If the heart rate drops below 100-120 beats per minute in an anesthetized cat, the heart rate needs to be increased and the anesthetic depth should be evaluated. If appropriate, atropine may be administered in this situation, and anesthetic gas turned down if possible.

Which of the following catheters would allow the largest volume of fluids to be given over the shortest amount of time?

16g x 1" explanation - Catheters that are shorter in length and larger in diameter can deliver the largest volume of fluids in the shortest amount of time. This is known as Poiseuille's Law.

Anesthetic monitoring of pet patients is one of the most important veterinary technician duties. How often should vitals be checked and recorded?

5 minutes explanation - Most places require that readings be taken at 5 minute intervals. The requirements may vary by state or facility.

What is the function of soda lime in an anesthetic machine?

Absorb carbon dioxide explanation - Soda lime is used in rebreathing anesthetic systems to absorb carbon dioxide and prevent it from accumulating in the circuit.

Padding is extremely important when a horse is under general anesthesia. When the animal is placed in dorsal recumbency, how much padding is required between the surgical table and the horse?

At least six inches explanation - At least six inches of padding should be used to prevent neuropathies of the head, shoulder, and hip.

When anesthetizing a rabbit for anesthesia, which vein is most often used?

Auricular explanation - The auricular (ear vein) is most often used in rabbits when IV access is necessary. For short procedures in private practice, subcutaneous or intramuscular injectable anesthetics are are often given, or a gas induction is used.

Which species commonly has laryngospasm when you are trying to place an endotracheal tube during anesthetic induction?

Cat explanation - Cats very commonly have laryngospasm, which can make it tricky to get the endotracheal tube placed. A drop of topical anesthetic can help to facilitate easier placement.

What is the most common location for placement of an arterial catheter (a-line) in a dog?

Dorsal metatarsal artery explanation - The dorsal metatarsal artery is most commonly used for placement.

For which species is it most common to clip and clean the surgical site prior to anesthetic induction?

Horse explanation - Out of the species listed, the horse is most amenable to being clipped and cleaned prior to surgery. Clipping and cleaning prior to anesthesia will help reduce the amount of total anesthesia time.

Certain drugs may cause a rapid rise in temperature during anesthesia. This is known as malignant hyperthermia. Which species is at greatest risk for this condition?

Porcine explanation - Pigs are at greatest risk for malignant hyperthermia. It is thought that this condition may be hereditary. During anesthesia in pigs, this must be monitored very closely as early detection is essential to prevent fatality. Cooling measures, Dantrolene, and oxygen are all implicated in treatment.

The glomerular filtration rate (GFR) is directly related to which of the following?

Rate of blood flow to the kidneys explanation - Glomerular filtration rate (GFR) is a test used to check how well the kidneys are working by estimating how much blood passes through the glomeruli each minute.

You are monitoring a 2 kg kitten being spayed at the humane society; she is intubated and is on isoflurane gas for maintenance. She is on IV fluids at 10 mL/hr. Her blood pressure starts to drop during the procedure. You have already given her a bolus of fluids. Which of the following should you do first to try to increase her blood pressure?

Turn down the anesthetic gas explanation - Anesthetic gas is a potent vasodilator and causes profound hypotension, especially in small patients. Decreasing the vaporizer setting in addition to crystalloids and colloids can help to facilitate raising the blood pressure. If the pressure cannot be managed by these simple measures, drugs such as dobutamine may be needed to help with blood pressure during the procedure. A dose of atropine will not increase blood pressure directly; it will only increase the heart rate. Good heat support actually helps to keep blood pressure more stable and is especially important in small patients to prevent hypothermia. A 90 ml/kg bolus would be a "shock dose" of fluids for a dog but is too much for a cat, and this cat is hypotensive for other reasons.

Pre-anesthetic drugs are used for all of the following reasons except which of the following?

To decrease the blood pressure explanation - Decreasing blood pressure is not a goal of a pre-anesthetic drug. Pre-meds help to reduce anxiety in the patient which allows for a smoother induction with fewer drugs and a smoother post-operative recovery. Many pre-anesthetic agents also provide analgesic effects.

Which of these drugs can be used to reverse anesthesia induced by xylazine in a cat?

Yohimbine explanation - The alpha-2 agonists are xylazine, clonidine, detomidine, romifidine, and medetomidine. Alpha-2 antagonists are yohimbine, tolazoline, and atipamezole. Flumazenil reverses benzodiazepines such as midazolam. Naloxone is an opioid antagonist (which would reverse morphine and hydromorphone).

You are responsible for anesthetizing an adult cat. What size endotracheal tube would you have ready for this patient?

#4 explanation - The average adult cat is properly intubated with a #4 endotracheal tube. A #2 would be too small for an adult. It could be used for a young kitten. The #6 and #8 would be too big for a cat and would be applicable for small to medium dogs.

A dog having a rough recovery from anesthesia has been ordered to receive 0.02 mg/kg of acepromazine. The dog's body weight is 40 lbs, and the acepromazine is diluted to a 1 mg/ml solution. How much acepromazine should this patient be administered?

0.36 ml explanation -First, convert the body weight to kilograms.40 lbs / (2.2 lbs/kg) = 18.2 kg Now determine the amount of milligrams needed. 0.02 mg/kg x (18.2 kg) = 0.36 mg (note the kilograms cancel out) Finally determine the amount of milliliters needed. 0.36 mg / (1 mg/ml) = 0.36 ml (note the milligrams cancel out)

What is the approximate minute volume of a 4 kg cat?

1 L explantion - The minute volume is the volume of air inspired during one minute of respiration. In cats, the typical minute volume is 180-380 ml/kg/min. For a 4 kg cat, the choice of 1 L per minute is the only one that is close to this range.

A cat is having a surgical procedure. How long should food be withheld prior to general anesthesia?

10 hours explanation - General anesthesia can decrease swallowing reflexes and esophageal sphincter tone. Patients may experience vomiting during or after anesthetic procedures. This predisposes them to esophagitis, esophageal stricture, or aspiration pneumonia. Domestic animals should be fasted prior to any anesthetic procedure. The amount of time varies by species, but in general food should be withheld for 8-12 hours in dogs, cats, and horses and 24-48 hours for cattle. Neonates should not be fasted prior to anesthesia and small patients (under 2 kg) should be fasted for shorter lengths of time. Water should be withheld for less time to avoid causing dehydration, which can be exacerbated by anesthesia; 2-4 hours is generally sufficient for dogs and cats. Ref. McCurnins Clinical Textbook for Veterinary Technicians, Elsevier, 2010. p. 889

An animal needs to be sedated with Dexmedetomidine. The patient weighs 2200, lbs and the dose that the clinician wishes to administer is 10 micrograms per kilogram. Dexmedetomidine is available as a 1 mg/ml solution. How many milliliters will be administered?

10 ml explanation - To solve this question, it is very important to know that there are 1000 micrograms in 1 milligram. Similarly, there are 1000 milligrams in 1 gram. First, convert body weight to kilograms. 2200 lbs / (2.2 lbs/kg) = 1000kg1000kg x (10 micrograms/kg) = 10,000 micrograms 10,000 micrograms / (1 milligram/1000 micrograms) = 10 milligrams (Notice the micrograms cancel out.) 10 mg / (1 mg/ml) = 10 ml This question is critical to understand. Not having a good grasp of the difference between a milligram vs. microgram vs. gram can result in misdosing a patient.

A patient's fluid rate is currently set at 150 ml/hr. The doctor asks you to decrease the fluid rate by 25%. What is the new rate?

112.5 ml explanation - First, we need to determine how much 25% of 150ml is. 150 ml x 0.25 = 37.5 ml Now, subtract the answer above from the original fluid rate to determine the new rate. 150 ml - 37.5 ml = 112.5 ml

You want to give a pre-surgical dose of antibiotics to your patient. You have a 1 gram vial of cefoxitin that is reconstituted with 5 mls of sterile water. You want to give a 20 mg/kg dose to a 25 kg dog. How many mls do you give?

2.5 explanation - The resulting concentration of the cefoxitin solution is 1gm/5ml or 200mg/ml. The desired dose is 20mg/kg x 25 kg = 500 mg 200 mg/ml x ____ ml= 500 mg, Therefore the answer is 2.5 ml

A patient is hypoventilating and the end-tidal CO2 is rising. The doctor instructs you to give the patient a breath. The pressure on the manometer to which you ventilate the patient is:

20 cm H2O explanation - When inflating the lungs, the pressure should reach but not exceed 20 cm H2O.

What is the ideal time period to withhold food in large ruminants prior to general anesthesia for an elective procedure?

24-48 hours explanation - Bloat results from continuous fermentation in the rumen when the ability to eructate is absent. In general there is less risk of bloat if cattle are fasted for 48 hours prior to anesthesia. This may not always be possible in emergency situations, but ideally for an elective procedure should fast for at least 24-48 hours.

Thiopental is a barbiturate used to induce anesthesia. Once reconstituted it is a 2% solution. The attending veterinarian asks you to induce a 27 kg dog with a dosage of 10 mg/kg. How many milligrams do you need, and how many milliliters will you draw up into the syringe?

270 mg / 13.5 mls explanation - 27 kg multiplied by 10 mg/kg = 270 mg. A 2% solution is equal to 20 mg/ml. 270 mg divided by 20 mg/ml = 13.5 mls

Perioperative antibiotics are essential in preventing unwanted infections. What is the best time to administer the antibiotic?

30 minutes prior to making an incision explanation - Research has shown that the best time to administer perioperative antibiotics is approximately 30 minutes prior to making an incision. This allows time for the antibiotics to have adequate circulating blood levels, resulting in good protection. By convention, most surgeons will repeat a dose of antibiotics every 90 minutes while in surgery. There is no literature to support the use of antibiotics after surgery in uncomplicated surgeries. If there is substantial contamination, break in technique, or other indication for continued use of antibiotics such as discovery of an abscess, then it is beneficial.

Which of the following is the best approximation of the typical tidal volume of a 20 kg dog?

300 ml explanation - The tidal volume is volume of air that is normally displaced during inspiration and expiration. Typical tidal volume for a dog is about 15 ml/kg (slightly more for smaller dogs and slightly less for large dogs). Tidal volume can be used to help estimate minute volume and the necessary fresh gas flow rates with various gas anesthesia machines.

Which of the following is considered a normal pulse oximetry reading?

98% explanation - Pulse oximetry measures oxygen saturation. Normal oxygenation is greater than 96% on average. It can be difficult to always get an accurate reading on an awake animal due to pigmented skin, fur, and/or the cooperation of the animal. Typical places for readings on an awake animal are the ears or lips. During anesthesia, the reading is on the tongue. If the pulse oximetry drops during anesthesia, wet and massage the tongue and take another reading.

Which anesthetic breathing circuit should be used for rabbit anesthesia?

A breathing circuit with minimal dead space explanation - As with small animal anesthesia, as a general rule, any patient under 7 kilograms should be placed on a nonrebreathing circuit. These offer minimal dead space, less resistance to breathing, and provide faster changes in anesthetic depth. Precision vaporizers should always be used in small mammal anesthesia, but this does not change the need for minimal dead space.

What is the neurotransmitter for skeletal muscle?

Acetylcholine explanation - Acetylcholine (ACh) is the transmitter for skeletal muscle and is located at the terminal ends of each motor neuron. Acetylcholinesterase destroys ACh and thus turns off muscle activity. GABA and Dopamine are CNS neurotransmitters. Norepinephrine is an inhibitory neurotransmitter in smooth muscle.

You are asked to recover a patient after surgery. When should you pull the endotracheal tube?

After the patient has an adequate swallowing reflex explanation - The endotracheal tube should be pulled when the animal has an adequate swallowing reflex. Brachycephalic breeds should have their tube kept in as long as possible due to their predisposition for respiratory problems.

Which of the following drugs is a neuroactive steroid and general anesthetic?

Alfaxalone explanation - Alfaxalone is a neuroactive steroid and general anesthetic used in veterinary practice under the trade name Alfaxan. It achieves its central effects via interactions with GABA receptors (as with most anesthetics). It is licensed for use in both dogs and cats. Thiopental is a barbiturate. Telazol is a combination of tiletamine (a dissociative anesthetic) and zolazepam (a benzodiazepine derivative). Propofol is a short-acting, lipophilic intravenous general anesthetic.

Gas exchange occurs between air and blood by diffusion through which structure?

Alveoli explanation - The alveoli are the site of gas exchange. They are tiny air sacs in the lungs that exchange carbon dioxide and oxygen and are located at the last branching of the respiratory tract. They are lined with simple squamous epithelium. The oxygen diffuses through the epithelium and the capillary endothelium in the exchange. The upper airway is lined mostly with pseudostratified columnar epithelium.

You are opening the boxes from today's shipments and find soda lime. What is this used for?

Anesthesia machine explanation - Soda lime or ("Sodasorb") is used in the anesthesia machine. In the machine, these granules absorb carbon dioxide exhaled by the patient in a rebreathing anesthesia circuit.

While performing an epidural on a dog, your needle begins to fill with a clear pale straw colored fluid, what is the appropriate action?

Aspirate and if there is no blood it is ok to administer half of the calculated dose of anesthetic. explanation - The fluid is cerebrospinal fluid (CSF); this means you have punctured the ligamentum flavum and the needle has entered the subarachnoid space. Only half of the dose should be administered.

What is the major concern when a patient has a long recovery post-op and is laterally recumbent for an extended period of time?

Atelectasis explanation - Atelectasis is collapse of all or part of a lung. In a patient who is recumbent for a long period of time, there is increased risk that the lung could collapse (usually the lung that is down). This is why it is so important to turn the patient every 15 to 20 minutes after recovery. Turning the patient will help them to recover more quickly and will help to prevent atelectasis.

What is another name for a non-rebreathing anesthesia circuit?

Bain system explanation - The Bain system is a non-rebreathing system. All non-rebreathing circuits lack unidirectional valves and soda lime carbon. They are used in patients less than 10 lb. In the non-rebreathing circuit oxygen flows through a flowmeter and into the vaporizer. At this point, gases exiting the vaporizer go directly to a hose for delivery to the patient with no inhalation flutter valve. Exhaled gases pass through another hose and may enter a reservoir bag but do not enter a CO2 absorber. The gas is then released into a scavenger. In a circle or rebreathing circuit (used in patients over 10 lb.), gases exhaled by the patient travel through the expiratory hose and enter the CO2 canister. They are directed into the reservoir bag and back toward the patient through the inhalation flutter valve. Oxygen and anesthetic gas enter the circuit here from the vaporizer and mix with the patient? exhaled gas.

Which of the following components of an anesthetic machine needs to be replaced regularly?

Barium lime explanation - Barium lime is a carbon dioxide absorber that can become exhausted (lose its ability to absorb carbon dioxide) and must be replaced. The other components listed can be re-used.

What part of the brain controls heartbeat, respiration, and blood pressure?

Brain stem explanation - The brain stem is made of the midbrain, pons, and medulla. It controls basic vital functions such as breathing, heartbeat, and blood pressure.

The main stimulus for ventilation is the partial pressure of which of the following gases?

Carbon dioxide explanation - Elevations of carbon dioxide are the main stimulus for respiration. Low levels of oxygen can also stimulate ventilation; however, carbon dioxide is a more potent stimulant.

What is a main function of a red blood cell?

Carry oxygen to the tissues explanation - Red blood cells have hemoglobin in their cytoplasm which binds oxygen and causes the red color of the cells. They are responsible for carrying oxygen to the tissues. Platelets help clot a wound. Leukocytes such as macrophages phagocytose bacteria and viruses. Mast cells produce histamine.

While the surgeon is focused on the task at hand, it is the anesthetist's job to make sure the patient's vitals are maintained at a normal plane. Which of the following is not suggestive of significant blood loss?

Cyanotic mucous membranes explanation - Patients suffering from substantial blood loss can be expected to have tachycardia, tachypnea, and weak pulses. In addition, pale/white mucous membranes as opposed to cyanotic mucous membranes would be noted. Cyanotic mucous membranes are seen when the patient lacks oxygen.

As a technician, it will be your responsibility to administer medications in most situations. Which of the following is not a common medication administered to horses post-operatively?

Dexamethasone explanation - Dexamethasone is a steroid and is not a commonly used medication post-operatively. When this medication is noted as a treatment after surgery, the technician should double check with the clinician in charge. Inadvertent administration of steroids can result in immunosuppression and secondary infection at the surgical site. Banamine is a very commonly used non-steroidal anti-inflammatory in horses. Procaine-penicillin G is a commonly used antibiotic which may be used by clinicians post-operatively. Omeprazole is a proton pump inhibitor that decreases the amount of stomach acid production in horses to help keep them from developing gastric ulcers.

What is the name for the blood pressure measurement when the ventricles of the heart are relaxed?

Diastolic pressure explanation - Diastolic pressure (DP) is the minimum arterial pressure during relaxation and dilation of the ventricles, which represents the pressure when the heart is resting. The systolic pressure (SP) is the pressure when the heart is contracting. Mean arterial pressure (MAP) is essentially an average blood pressure that represents the perfusion pressure seen by the organs in the body. It is calculated by using the systolic and diastolic pressures as seen by the formula: MAP=DP + 1/3 (SP-DP) Central venous pressure (CVP) is the pressure of blood in the thoracic vena cava and is a good estimation of right atrial pressure. CVP reflects the amount of blood returning to the heart and the ability of the heart to pump blood. Mean corpuscular volume is a laboratory term used to describe average volume of a red blood cell that helps to classify an anemia as microcytic or macrocytic.

Which of the following description of the properties of an inhalant anesthetic is true?

Drugs with low minimum alveolar concentrations (MAC) are the most potent

Which of the following statements regarding inhalant anesthetics is true?

Drugs with low solubility (blood/gas solubility coefficients) produce rapid induction and recovery rates explanation - The solubility of an inhalant anesthetic determines the speed of induction and recovery. Low solubility drugs produce rapid induction and recovery. Listed from least to most soluble, inhalant anesthetics include desflurane, sevoflurane, isoflurane, enflurane, halothane, and methoxyflurane. Therefore, desflurane has the fastest induction and recovery rates, and methoxyflurane has the slowest. MAC is a measure of anesthetic potency or the concentration of drug required to prevent response to a stimulus in 50% of patients.

A laryngoscope might aid in which procedure?

Endotracheal tube placement explanation - A laryngoscope is a handheld instrument that has a blade with a light source; it helps to hold down the tongue and view the epiglottis and laryngeal region. It is used to examine this area of the oral cavity and is also used to assist with endotracheal tube placement.

Which of the following is true regarding anesthesia of reptiles?

Fasting is not usually necessary explanation - Regurgitation during anesthesia is not a concern for reptiles, and thus fasting is not usually necessary unless they are undergoing gastrointestinal surgery. The rough nature of reptile skin makes it difficult to aseptically prep for surgery. A stiff brush with antiseptic solution should be used for preparation of the skin. Reptiles are prone to hypothermia. They are ectothermic and hold their breath so heat support is extremely important for better control of anesthesia. Reptiles are susceptible to microbial infections; stress from surgery may potentiate these infections (and the skin is difficult to sterilely prep). Perioperative antibiotics are almost always warranted.

Which of the following is an indicator that a spinal needle has successfully been placed into the epidural space in a horse?

Fluid is immediately drawn in when placed on the hub of the needle explanation - A horse epidural should be placed between the last sacral and first coccygeal vertebrae or between the first and second coccygeal vertebrae. When placed correctly, fluid will be drawn into the hub. Spinal fluid is a sign that the needle is not in the epidural space. The push of fluid into the spinal needle should be very smooth. Any resistance is an indication that the needle is probably not in the epidural space.

A dog under anesthesia has an end-tidal CO2 (ETCO2) reading of 60 mm Hg. What should be done?

Give the patient a breath, or ventilate, to lower the ETCO2 explanation - If the patient has an ETCO2 greater than 55, the patient is hypoventilating. Giving the patient some breaths, or ventilating the patient, will help to lower this value. Increasing the oxygen flow rate would increase the amount of anesthetic flowing through the circuit. Atropine would increase the heart rate. Typically, a patient in a light plane of anesthesia would be hyperventilating and may have a lower ETCO2 (less than 30).

Anticholinergics can be used in small mammals as part of a preanesthetic protocol. Of the following, which anticholinergic is the best choice for use in rabbits?

Glycopyrrolate explanation - Both atropine and glycopyrrolate can be used in small mammals, but glycopyrrolate is preferred for use in rabbits. This is because the effect of atropine is less effective in this species because many animals have high levels of atropinesterase. Both diazepam and midazolam are benzodiazapines, not anticholinergics.

Many times, horses require additional muscle relaxation during anesthesia. Which of the following is commonly used for its property of being a centrally acting muscle relaxant?

Guaifenesin explanation - The correct answer is guaifenesin. Unfortunately, the exact mechanism is unknown; however, we do know that guaifenesin acts centrally by blocking nerve impulse transmission at the internuncial neuron level in the subcortical brain, brain stem, and spinal cord. Early signs of toxicity are in the form of increased rigidity. Ketamine is a dissociative agent and is known for its ability to cause hypertonia. Atracurium is a non-depolarizing neuromuscular blocking agent that acts by competitively binding to cholinergic receptors at the motor endplate. Succinylcholine is a depolarizing neuromuscular blocking agent.

Which anesthetic gas would be most likely to induce a cardiac arrhythmia?

Halothane explanation - While any of the inhaled anesthetics may cause cardiac arrhythmias, they would be more likely to occur with the use of Halothane gas. Because of this, most veterinary practices have moved toward the use of Isoflurane or Sevoflurane for anesthetic maintenance during procedures.

When cattle are placed in lateral recumbency during general anesthesia, how should the head be positioned to decrease the risk of aspiration?

Head and oral cavity lower than the neck explanation - During general anesthesia the esophageal sphincter relaxes, and if regurgitation occurs the fluid can be aspirated. Positioning the head and oral cavity lower than the neck paired with a properly inflated endotracheal cuff can reduce this risk.

Prior to placement of an endotracheal tube, you measure the tube so you know how far in to place it. Where should your measurement be?

In between the larynx and the thoracic inlet explanation - The tube should be pre-measured to be placed midway between the larynx and the thoracic inlet.

Oscillometric or Doppler equipment is a way of measuring what parameter?

Indirect blood pressure explanation - Oscillometric and Doppler machines measure indirect blood pressure and are often used in the clinical setting. These methods are non-invasive and easy to perform. (The Dinamap is an example of an oscillometric machine.) Direct blood pressure measurements are taken when an animal has an arterial line in place; they are typically used only in patients that are critical and undergoing major surgery.

Which of the following drugs can induce muscle rigidity, or a cataleptic state, during anesthesia?

Ketamine explanation - Catalepsy can be caused by ketamine and morphine. Ketamine (a dissociative anesthetic) is usually given along with diazepam (Valium) to counteract the muscle rigidity it causes. Ketamine can also result in increased intracranial pressure. Diazepam causes muscle relaxation. Acepromazine is a phenothiazine tranquilizer. Propofol is an anesthetic induction agent that is a hypnotic and does not cause catalepsy.

Which of the following sedative or anesthetic drugs would NOT frequently cause hypotension (low blood pressure)?

Ketamine explanation - Ketamine's effects on the cardiovascular system include increased cardiac output, increased heart rate, and increased blood pressure. These cardiovascular effects are secondary to increased sympathetic tone. Isoflurane and other inhalant gases can cause profound hypotension. Acepromazine and propofol also very commonly cause hypotension.

You are using a Bain circuit to anesthetize a ferret for a spay procedure. Which of the following measures is the most important thing to do to prevent re-breathing of carbon dioxide by the ferret?

Maintain high flow rates of oxygen in the circuit explanation - A Bain circuit is a non-rebreathing system (in contrast to circle systems used more commonly in animals over 5kg). Therefore, there is no carbon dioxide absorber such as soda lime. Instead, you must use sufficient oxygen flow rates to constantly flush the system (typically at least 100 ml/kg/min). The system is not dependent on valves like a circle system is. A long endotracheal tube will increase re-breathing and should not be used.

What heart valve is responsible for separating blood between the left atrium and left ventricle?

Mitral valve explanation - The mitral valve is also known as the bicuspid valve and is responsible for separating blood between the left atrium and left ventricle. The right atrium receives deoxygenated blood from the vena cava. This blood is then pumped into the right ventricle (passing through the tricuspid valve) which then gets pumped into the lungs (passing through the pulmonary valve) via the pulmonary artery for oxygenation. The newly oxygenated blood returns to the left atrium via the pulmonary vein. Once in the left atrium, the blood is pumped into the left ventricle (passing through the mitral valve) from which it is then pumped into circulation via the aorta (passing through the aortic valve).

In the United States, what type of gas is in a blue gas tank?

Nitrous oxide explanation - In the United States: Blue indicates nitrous oxide Gray = carbon dioxide Yellow = medical compressed air Green = oxygen Black= nitrogen Brown= helium Other countries use different color markings. Gas mixtures are indicated by two or more designated colors on the cylinder.

Which of the following is NOT a contraindication of epidural placement in the dog?

Obesity explanation - Obesity is not a contraindication, but it may make finding the landmarks difficult while placing an epidural. Occasionally fractures of the sacrum or pelvis can cause abnormal anatomy and an epidural should not be attempted. If a coagulopathy exists, an epidural should not be attempted to avoid potential bleeding. Skin infections at the epidural site can lead to systemic infections if bacteria is introduced to the epidural space by the needle.

You are hooking up the anesthesia machine and place the pulse oximeter on the dog's tongue. This is to measure which of the following? (photo: small dog w/ a clip on its tongue)

Oxygen saturation explanation - Pulse oximetry measures oxygen saturation of hemoglobin in arterial blood. The pulse-ox reading should generally always be above 94%. If this measurement drops, especially during anesthesia, sometimes rubbing and wetting the tongue can help improve circulation to the tongue and thus help get a more accurate reading.

Which anatomic structure is the passageway for both the respiratory and digestive systems?

Pharynx explanation - The pharynx leads from the oral and nasal cavities to the larynx and esophagus. It helps to get food to the esophagus and air to the lungs.

Myositis in a horse can occur as a result of which of the following?

Prolonged recumbency during anesthesia explanation - Prolonged recumbency puts a horse at a high risk for developing myositis. It is extremely important for the anesthesia team to provide appropriate padding by means of rubber pads, inflatable tubes, or even an inflatable water bed to help decrease the pressure exerted on muscles as result of recumbency. Intraoperative hypotension can contribute to myositis due to lack of blood flow and subsequent ischemia at the level of the muscle. Myositis can result in extreme muscle pain and soreness. In severe cases, horses can develop myoglobinuria which can cause renal damage. The blood lactate level of 1.0 mg/dl is actually in the normal range; however, an increasing blood lactate level is a sign of anaerobic metabolism, which may be secondary to poor muscle oxygenation; the cause should be investigated and addressed.

Which anesthetic is short-acting, white-opaque in color, and can cause transient apnea on induction?

Propofol explanation - Propofol is an opaque-white short-acting anesthetic or sedative for intravenous use and is often used for anesthetic induction or sedation for short procedures. It can cause respiratory depression or transient apnea, especially when given too quickly.

Which of the following breeds would be considered brachycephalic?

Pug explanation - A brachycephalic skull is relatively broad and short. Because of their conformation, dogs of this type more susceptible to respiratory problems. "Brachycephalic Airway Syndrome" includes elongated soft palate, everted laryngeal saccules, and stenotic nares (narrow nostrils). These animals are also more prone to ocular problems. The most common (and visually obvious) dogs in this class include the Pug, Shih Tzu, Bull dog, Pekingese, Boston terrier, and Cavalier King Charles spaniel.

Oxygenated blood returning from the lungs travels in which blood vessel?

Pulmonary vein explanation - Vessels that contain blood moving toward the heart are known as veins despite their oxygenation status. The pulmonary vein is responsible for returning oxygenated blood to the heart (via the left atrium) for distribution the rest of the body. The pulmonary artery contains deoxygenated blood from the right ventricle that is moving toward the lungs for oxygenation.

Which of the following is the "minute volume" of a patient under anesthesia?

Respiratory rate multiplied by tidal volume explanation - Minute volume is the volume of air that is inspired by a patient in one minute. It is calculated by multiplying tidal volume by the number of breaths per minute. The tidal volume is the volume of air that is inspired on each breath. The respiratory rate is the number of breaths per minute. Tidal volume is usually considerably smaller than the total lung capacity.

Which is the correct direction through the heart in which blood flows?

Right atrium, tricuspid valve, left atrium, mitral valve explanation - The tricuspid and mitral valves are both atrioventricular valves that divide the right sided chambers and left sided chambers, respectively. To follow blood flow through the entire body: Blood flows from the right atrium, to the tricuspid valve, right ventricle, pulmonic valve, pulmonary artery, lungs, pulmonary vein, left atrium, mitral valve, left ventricle, aortic valve, aorta, then to the rest of the body.

Name the heart chamber responsible for pumping blood toward the lungs.

Right ventricle explanation - The right atrium receives deoxygenated blood from the vena cava. This blood is then pumped into the right ventricle (passing through the tricuspid valve) which then gets pumped into the lungs (passing through the pulmonary valve) via the pulmonary artery for oxygenation. The newly oxygenated blood returns to the left atrium via the pulmonary vein. Once in the left atrium, the blood is pumped into the left ventricle (passing through the atrioventricular valve) from which it is then pumped into the circulation via the aorta (passing through the aortic valve).

In what order does an electrical impulse travel through the heart?

SA node, AV node, Bundle of His, Purkinje fibers explanation - The sinoatrial node (SA node) is the pacemaker of the heart located in the wall of the right atrium. It generates an electrical impulse that is carried to the atrioventricular node (AV node) which is located between the atria and ventricles. The impulse is then relayed down the conducting tissues, or the Bundle of His, and branches to the paths that supply the right and left ventricles (the right and left bundle branches). Purkinje fibers are reached last and are conductive fibers within the walls of the ventricles that relay the impulses to the cells that cause contraction of the ventricles. This process of impulse travel is known as depolarization.

Stimulation of the Vagus nerve results in which of the following?

Slowed heart rate explanation - Vagal stimulation slows the heart rate.

Anesthetic monitoring is extremely important in the operating room. If you are in surgery with a cat, which of the following parameters would you consider abnormal?

Temperature of 93.7F explanation - Of the parameters listed, the low temperature is most alarming. Heat support is extremely important in the anesthetized patient. Draping of the patient, using a warm air system or heat blanket, placing a towel between the patient and the operating table are all measures to help maintain a normal temperature. It is not abnormal for that recovering patient to be hypothermic, but every effort should be made to minimize that. A systolic blood pressure above 90 and below 160 mmHg is ideal for a cat or dog. An end-tidal CO2 level in the range of 35-45 is considered normal. Any acute drop in PCV should be relayed to the surgeon. The PCV measurement in this question falls within the normal range.

A dog under anesthesia is hypoventilating. This means which of the following is true?

The CO2 level is high explanation - Hypoventilation (inadequate respirations) causes an increase in carbon dioxide levels (hypercapnia) and respiratory acidosis. If the end tidal CO2 is climbing, the patient should be given a breath or may need to be placed on a ventilator (especially if the ETCO2 climbs over 50).

You are taking indirect blood pressure readings on a cat with hyperthyroidism. Which is true when choosing a cuff for the patient?

The cuff diameter should be about 40% the circumference of the limb explanation - Oscillometric and Doppler readings are indirect blood pressure measurements and are most commonly used in the clinical setting. A blood pressure cuff is used, and the general rule is that the cuff diameter should be about 40% of the limb circumference. It is important that the cuff be proportional to patient size. If the cuff is too large, the reading will be inaccurately low. If the cuff is too small, the reading will be inaccurately too high. It is best to take an average of several readings for the most accurate measurement. Next Question

Approximately 5ccs of an inhalant anesthetic is spilled while the vaporizer on an anesthetic machine is being filled. What course of action should be taken?

The vaporizer should be closed and the room well ventilated explanation - The fire department should only be summoned if a significant amount of inhalant (gas) anesthetic is spilled, such as an entire bottle being dropped or broken. The hospital does not need to be evacauated unless there is no way to seal off the area where the spill occurred. Bleach is very reactive with a great number of chemicals and should never be used to clean up any chemical spill. Continuing to fill the vaporizer will expose staff to inhalant as the anesthetic evaporates. The best course of action would be to close the vaporizer, leave the room/area for 5-10 minutes and allow the air in the room to circulate either by opening an external door or increasing the air flow into the room using a fan or air conditioning unit.

When performing anesthesia in the horse, which of the following should always be done prior to induction and intubation?

Throughly rinse the oral cavity explanation - The oral cavity should always be rinsed to remove food particles to prevent introducing foreign material into the trachea.

For which of the following procedures would an epidural be of most benefit?

Tibial Plateau Leveling Osteotomy (TPLO) explanation - Epidural anesthesia provides analgesia and is of great benefit in orthopedic surgeries involving the hindlimbs in dogs. These are routinely performed in TPLO procedures, hip replacement surgeries, etc. and are also often used in cesarean sections.

In regards to rabbit anesthesia, which of the following best explains why the use of sedative premedications should be given prior to inducing anesthesia using a mask or induction chamber to deliver gas agents such as Isoflurane?

To help prevent breath holding explanation - Because rabbits often hold their breath and struggle when exposed to gas anesthetics, premedications such as dexmeditomidine, diazepam, or midazolam will facilitate smoother inductions.

In a non-rebreathing anesthesia circuit, which of the following is NOT used?

Unidirectional valve explanation - Non-rebreathing systems utilize high flow rates of fresh gas. They do not use unidirectional valves or soda lime since fresh gas is constantly flushing the system. The non-rebreathing circuit requires oxygen, a vaporizer, a scavenger, and typically has its own reservoir bag.

The somatic nervous system is responsible for which of the following functions?

Voluntary motor movement explanation - Secretion of saliva, contraction of the intestines, and regulation of the heart rate falls under the responsibility of the autonomic nervous system. More specifically, the heart rate is influenced by the parasympathetic and sympathetic nervous systems, both of which are branches of the autonomic nervous system.

Which of the following is not a complication associated with the placement of an epidural in a dog that is under anesthesia?

Vomiting explanation - Vomiting is generally not observed after placement of an epidural in the anesthetized patient. Dogs may however experience respiratory depression, urinary retention, and hypotension as a result of using epidural anesthetics such as opioids and alpha-2 agonists.

Which of the following pieces of information should the technician be most aware of prior to inducing a patient for anesthesia?

When the patient ate last explanation - Patients that are anesthetized with a full stomach have a higher incidence of vomiting or regurgitating at the time of anesthesia. Therefore, it is very important to have patients fasted prior to anesthesia. Depending on the species, some patients may be fasted anywhere between just a few hours to over 12 hours.

You are attempting to give an intra-jugular injection to a horse and insert the needle to the hub. Blood is forcefully pulsating and ejecting from the needle. What is the most likely explanation?

You are in the carotid artery explanation - This is typical of insertion into an artery. If this occurs, the needle should be removed immediately and pressure placed on the site for several minutes to assure hemostasis.