Anesthesia Quiz 3

What is the purpose of monitoring patients under anesthesia?

To warn the anesthetist of changes in anesthetic depth and patient condition in enough time to permit intervention

Monitoring is necessary for what two reasons?

• to keep patients safe

• to regulate anesthetic depth

Failure to monitor and maintain vital signs within acceptable limits may lead to devastating consequences such as what?

permanent brain damage or even death

____ - this type of monitoring consists of a physical assessment such as putting your hands on the patient or listening to heart sounds.

subjective

____ - this type of monitoring consists of connecting machines that calculate a number for the result, such as ECG or blood pressure

Objective

• Listeing to the heart sounds

• palpating pulse quality

• temperature

• assessing reflexes

• assessing respiratory character

• assessing MM and CRT

• assessing muscle tone

Are these all subjective or objective monitoring techniques?

subjective

• ECG

• blood pressure

• capnography

• pulse oximeter

Are these all subjective or objective monitoring techniques?

objective

What are some vital signs we monitor during surgery?

• heart rate/rhythm

• respiratory rate/depth

• MM/CRT

• pulse strength

• blood pressure

• temperature

What are some reflexes we monitor during surgery?

• palpebral

• corneal

• pedal

• swallowing

• larygneal

• pupillary light reflex

T or F: Both reflexes and other indicators are useful for determining anesthetic depth but are not useful for assessing cardiopulmonary function or homeostasis.

True

Swallowing and pedal reflexes are expected to be present when the patient’s anesthesia level is too ____

light

Muscle tone, HR, and RR are expected to be high during ____ anesthesia.

light

If the patient’s eyes are centrally positioned, what does this tell us?

that they are either under light anesthesia or deep anesthesia

If the patient’s eyes are rotated into the ventromedial position, what does this tell us?

They are in the correct surgical depth of anesthesia

General anesthesia is divided into how many stages?

4

Loss of consciousness marks the border between stages ___

I and II

Loss of spontaneous muscle movement marks the border between stages ____

II and III

Loss of reflexes, widely dilated and unresponsive pupils, flaccid muscle tone, and cardiopulmonary collaspe marks stage ____

IV

Which stage is known as the stage of voluntary movement? In this stage, the patient begins to lose consciousness, and is usually characterized by fear, excitement, disorientation, and struggling.

Stage I

Which stage is known as the stage of involuntary movement? This stage is characterized by involuntary reactions in the form of vocalizing, struggling, or paddling.

Stage II

Which stage is known as the excitement stage?

stage II

____ this stage is characterized by the HR/RR elevating, pupils are dilated, muscle tone is marked, and reflexes are present and may appear exaggerated.

Stage II

When does stage II anesthesia end?

It ends when the animal shows signs of muscle relaxation, slower RR, and decreased flex activity.

Stage III anesthesia is divided into how many planes?

4

This stage is known as the period of surgical anesthesia. The patient is unconscious and progresses gradually from light to deep anesthesia.

Stage III

____ - in this plane of stage III anesthesia you are able to intubate the patient. Their eyeballs start central, but will gradually start to rotate ventrally.

Plane 1 of Stage III

T or F: Patients are able to tolerate surgical procedures under plane 1 of stage III.

False

_____ - this plane of anesthesia stage III is the optimum depth for surgical/invasive procedures. Surgical stimulation may evoke a mildly increased HR or RR, but the patient will remain unconscious and immobile

Plane 2 of Stage III

____ - during this plane of anesthesia stage III, significant depression of circulation and respiration may be observed. Abdominal breathing may be observed.

Plane 3 of stage III

____ - this plane of anesthesia stage III is known as early anesthetic overdose. The patient is too deeply anesthetized and is in danger of respiratory and cardiac arrest.

Plane 4 of stage III

This stage is known as the period of anesthesia overdose. There is a cease of respiration, and the cardiovascular system is markedly depressed with a dramatic drop in HR and BP, accompanied by pale MM and prolonged CRT. Followed by circulatory collapse and death.

Stage IV

____ - a device used to display the electric impulses generated by the cardiac conduction system that iniate each heart beat.

ECG

In small animals, where should the white electrode be placed?

right axillary

In small animals, where should the black electrode be placed?

left axillary

In small animals, where should the red electrode be placed?

left inguinal

In large animals, where should the white electrode be placed?

right jugular furrow

In large animals, where should the black electrode be placed?

left jugular furrow

In large animals, where should the red electrode be placed?

apex of the heart

____ - the force exerted by flowing blood on arterial walls. Used during anesthesia to evaluate tissue perfusion.

blood pressure

Blood pressure is determined by complex interactions among what?

• heart rate

• stroke volume

• vascular resistance

• arterial compliance

____ - the volume of blood ejected by the heart on each beat/contraction

stroke volume

____ - the diameter of the vessels

vascular resistance

____ - is also known as the elasticity of blood vessels

arterials compliance

____ blood pressure is produced by the contraction of the left ventricle as it propels blood through the systemic arteries

Systolic Blood pressure

____ blood pressure is the pressure that remains in the arteries when the heart is in the resting phase between contractions

Diastolic blood pressure

_____ - the average pressure throughout the cardiac cycle

Mean Arterial Pressure (MAP)

What is the most important value from the anesthetist’s standpoint because it best indicates BP of the internal organs?

Mean Arterial Pressure (MAP)

What is the normal systolic arterial BP for dogs and cats?

110-160

What is the normal mean arterial BP for dogs and cats?

60-90

What is the normal diastolic arterial BP in dogs and cats?

50-70

What is the normal systolic arterial BP in horses and cattle?

>80

What is the normal mean arterial BP in horses and cattle?

60-90

What is the normal diastolic arterial BP for horses and cattle?

>50

T or F: Hypertension is common during anesthesia?

False, hypotension is common

Does blood pressure usually increase or decreased under anesthesia?

decrease

If MAP falls below ___mmHg in small animals, blood flow to internal organs is reduced and tissue becomes hypoxic.

60

If MAP falls below ___ in horses, there is deceases blood flow to the muscles

70

The oscillometic and doppler methods are both ___ methods used to collect blood pressue

noninvasive

Monitoring blood pressure through the arterial line is known as a ____ method

invasive

____ - estimates the saturation of hemoglobin (So2), expressed by a % of the total binding sites.

pulse oximetry

What is the normal pulse oximetry?

95-100%

A pulse oximetry of 90-94% must be investigated because it indicates the patient is what?

hypoxemic

A pulse oximetry less than 90% indicates need for what?

therapy

A pulse oximetry saturation less then 85% for longer than 30 seconds is considered what?

a medical emergency

____ - a noninvasive, continuous, and practical method of monitoring CO2 levels in anesthetized patients. Displays measurements of end-tidal CO2, inspired CO2, and real-time CO2 waveform.

Capnography

T or F: Capnography machines measure blood CO2 directly.

False, it measures expired CO2

_____ - with this type of capnograph, the sensor chamber is placed directly between the endotrachial tube and the breathing circuit. Could result in increased dead space but it gives immediate readings.

Mainstream capnograph

_____ - with this type of capnograph, the sensor chamber is located in the computerized monitor and air is pulled into it through a tube attached to a fitting between the endotracheal tube and breathing circuit. Tube is lightweight and adds little dead space.

Sidestream capnograph

In nonanestheszied patients, ETCO2 of ____mmHg is normal

35-45

In anesthesized patients, ETCO2 of ____mmHg in normal

55-60

A PaCO2 greater than 60 mmHg causes what?

respiratory acidosis

A PaCO2 less than 20 mmHg causes what?

respiratory alkalosis

____ - measurement of blood pH, and of dissolved O2 and CO2 in the arterial blood.

Blood gas analysis

What is the normal pH of blood?

7.35-7.45

What is the normal PaCO2 value?

35-45 mmHg

What is the normal PaO2 value?

4-5 times the fraction of inspired O2

What is the normal BE (Base Excess) value?

-4 -4

What is the normal bicarb (HCO3) value?

19-29

Will an increase in CO2 increase or decrease blood pH?

decrease

Will a decrease in CO2 increase or decrease blood pH?

increase

Will a decrease in HCO3 increase or decrease blood pH?

decrease

Will a increase in HCO3 increase of decrease blood pH?

increase

Why do we record during anesthesia?

• to maintain a legal recording of significant events related to the anesthetic period.

• to enhance recognition of significant trends or unusual values for physiological parameters and to allow assessment of the response to intervention.

You should record monitored variables on a regular basis, every ___ minutes during anesthesia.

5-10

If your patient does not have an IV catheter, how do we usually like to premed them?

intramuscularly

There are many different methods of induction. What are they, and which is the most common and provides the most control?

• Intravenous

• Intramuscular

• Mask

• Chamber

Intravenous is the most common and provides the most control.

What are we trying to accomplish with induction?

• unconsciousness

• relaxed jaw tone

• reduced/no swallowing

Which induction agent can cause apnea and stage II excitement is given too slowly?

Propofol

Which induction agent takes longer to produce unconsciousness and must be given with a muscle relaxer?

Ketamine/Midazolam

Which induction agent is similar to propofol but is more cardiovascular-friendly?

Alfaxalone

Which induction agent is expensive but is safest for cardiovascular system?

Etomidate

When should intramuscular induction be done over intravenous induction?

When patients are difficult/wild or very young such as puupies and kittens

T or F: Intramuscular induction takes longer to take effect and longer to recover. If a patient is too deep, the only option is to perform a complete reversal

True

When are mask/chamber induction most commonly used?

with fractious animals or exotics

What are a few cons of mask/chamber induction?

• It is impossible to assess most monitoring parameters while in the chamber.

• Considerable risk of exposure to waste anesthetic gas

• Wears off quickly

• Delay between the change in the dial and the change in the level of inhalant delivered to your patient

With endotracheal intubation, using a cuffed tube reduces the likelihood of what?

aspiration

____ - portions of the breathing passages that contain air but in which no gas exchange can occur (i.e., the mouth, nasal passages, pharynx, trachea, and bronchi)

anatomic dead space

How many endotracheal tubes should you have when preparing to intubate?

At least three different sizes. The size you think is appropriate, a size below, and a size above

Why do we use lidocaine when we intubate cats?

to prevent or minimize laryngospasm

What are the different types of endotracheal tubes?

• low volume high pressure

• high volume low pressure

• silicone

• PVC