Vital Signs

Textbook Assignment: please read Clinical Textbook for Veterinary Technicians by Bassert and McCurnin, Chapters 8, 10, pp. 174-182
 

Topics:
Evaluation of temperature
Evaluation of pulse
Evaluation of respiration
Evaluation of color
Evaluation of capillary refill
Evaluation of hydration

Objectives 
1)  List the normal range for the temperature, pulse and respiration of the dog, cat, horse, cow and sheep.
2)  Describe how capillary refill time, color and hydration are evaluated in the previous species and the significance of each.
3)  Explain techniques for obtaining the vital signs from the previous five species.
4)  List and explain how factors, such as environmental temperature, infection, shock and excitement, can affect temperature, respiration, pulse, color, capillary refill time and hydration.
5)  List four simple ways an owner can evaluate the health of their animal (not the vital signs).
6)  Describe how the behavior of exotic animals and livestock differ from well socialized pets during the early stages of illness.

Basic Patient Evaluation

It is the technician's responsibility to observe and evaluate patients. Patient evaluation techniques take practice to perfect.
Three of the most important parameters in this process are the traditional "vital signs" the temperature, pulse and respiration (TPR).

Temperature
One of the most important measurements of the physiological state of the patient is the body temperature. The best site to take the temperature in animals is at the rectum. 
Other areas used include (in small animals) the: 
Axilla (armpit) 
Inguinal region
Ear canal (special thermometer or probes are needed for these locations)
The patient's temperature is lower at these peripheral sites by 1 or 2 degrees. The temperature normally fluctuates slightly hour to hour and is affected by many things.  It is recommended that for the most accurate evaluation the temperature be measured several times to look for trends.

An increase in temperature can be caused by  many things including: 
Fear
Pain
Infectious disease
Exercise
Increased environmental temperature
The body temperature normally is highest in the late afternoon and lowest during deep sleep at night.
A decrease in temperature can indicate cold environmental temperature (hypothermia) and the physiological condition of shock, among other things.

Traditionally rectal temperatures have been collected using mercury thermometers. Although this is still a common means of temperature evaluation in veterinary medicine, new digital thermometers are also used frequently. Certain procedures should be followed regardless of the type of thermometer.
Thermometers should be clean and disinfected for every patient.
Thermometers should be gently inserted deep enough to get the core body temperature and left in place a specified length of time (most of the time a minimum of 90 seconds with mercury thermometers).

Mercury thermometers
These are supplied in various sizes, the large sizes often have an eye at one end to tie a string on for use in large animals.
What is the purpose of the string?

Thermometers are calibrated on the side in either degrees Centigrade/Celsius or Fahrenheit.

Which scale is used most commonly in the Unites States?

When taking the temperature always shake the thermometer down first. It might need to be lubricated, especially for cats, for easier insertion and less trauma to patient.
The deeper it is inserted the more accurate the reading, as it will be closer to the core body temperature.  The thermometer must go in at least an inch (depending on the size of the patient) for accurate results. If the first reading seems unrealistic shake down the thermometer and try again.
Sometimes it can be hard to read the temperature on the magnified scale of the mercury thermometer, by rotating the thermometer the reading usually comes in view.

If a mercury thermometer breaks on the examine room table or floor should the client pick it up? Why?

Digital or electronic thermometers: This technology enables much faster,  easier and very accurate readings.  In some models the probes or plastic probe covers are disposed between patients. These thermometers are more expensive, and some can be used in alternative sites.

Technique for temperature evaluation.
1)  Restraint of patient  standing or lying lateral
2)  Lubricate and gently insert clean thermometer (did you shake it down?)
3)  Wait for reading (usually at least one and a half minutes)
4)  Remove thermometer, record reading (if applicable)
5)  Shake down thermometer and clean and disinfect it.

Species variations:
Cats dislike having their temperatures taken.  Be sure to lubricate the thermometer well. The small size and quick readings of digital thermometers work well in cats.

With livestock and horses the challenge is to avoid getting kicked.  Sometimes the patient is not used to having their tail manipulated.  Always stand next to the body, facing backwards, and to the side when taking the temperature of a horse. By being next to the body if the animal does kick there is less "power" when the leg is not fully extended and less chance of serious injury. Gently lift and move the tail to one side to insert the thermometer. 

Cattle generally kick to the side so it is safer to stand directly in back of them.  Their tail muscles are not as strong as those of a horse and the tail can be lifted upward to insert the thermometer. This will make the cow move forward so it should be confined before using this technique.

Pulse

The pulse is a measurement of the blood pulsations through an artery.   A normal pulse should equal the number of heartbeats. The pulse and heartbeat can provide different information, the pulse gives an indication of the strength of blood flow to peripheral tissue.  The pulse can be felt (palpated) at sites where the vessels pass over bony protuberances or where major vessels enter the legs.  The pulse is best monitored using the fingers, not the thumb.
Why?

The pulse is evaluation for:
1)  Rate or pulsations per minute
2)  Rhythm or regularity of the pulsations
3)  Consistency or strength, a weak pulse is sometimes described as "thready" the blood volume and or blood pressure is low.

The heart can be palpated or auscultated  to determine beats per minute also, but the pulse provides different information than listening to the heart. Heart sounds are evaluated for rate, regularity and functioning of the heart valves. Auscultation of the heart and lungs will be discussed in more depth in Clinics I (VET 121).
The heart rate (with stethoscope) can be measured at the same time the pulse is palpated to check for a pulse deficit. If the heart  beats more often than the pulse is felt (a pulse deficit) this can signify a serious heart disorder.

Species variations
Dog and cat:
The easiest site to evaluate the pulse is the femoral artery at the medial aspect of hind leg. 
The animal can be standing or in lateral recumbency.  It should be still. The fingers are placed high in the inguinal area and the vessel is pressed between the index and second fingers and the femur. 
Other pulse points are more difficult to palpate.  The dorsal metatarsal artery on the anterior surface of the hind leg below the hock, the lingual artery on the bottom of the tongue and the ulnar artery on the palmar or posterior surface of the front leg at the carpal region can also be evaluated.

                                                
click on photo to see enlargement.

The Horse
The sub-mandibular artery , also termed mandibular artery which runs under the jaw is the preferred site to monitor the pulse.  It is large and somewhat variable in location (more anterior in some patients). Because the horse's pulse is so slow it maybe difficult to pick up at first. 
Another pulse site frequently used is the digital artery on the palmer surface of the front pastern. This pulse is checked to determine if the horse is suffering from laminitis.

Cow: The most frequently used pulse point on the cow is the facial artery. It is an extension of the mandibular artery (just mentioned in the horse), and extends anteriorly to the facial area.
Are there differences in the pulse rates between young and old animals?

Respiration

Respiration is recorded as the number of breaths in one minute.  Respirations can usually be evaluated in two ways, at the nostril or the chest.  The easiest way is to watch the movement (rising and falling) of the chest wall, remember, one breath includes both inspiration and expiration.  In some species the respiratory rate may be hard to monitor by watching the chest. In these cases it might be possible to detect  breathing directly at the nostril.  By holding your hand, or a piece of tissue or hair in front of the nostril, each expiration can be detected.
It is difficult to count the number of breaths while a dog (or rarely a cat) is panting, most veterinarians will accept "panting" or TNTC (to numerous to count) written in the record.

Increases in respiratory rate can be due to many things including: 
Excitement
Fear
Hyperthermia
Pain
Fever
Exercise
Diseases of the lungs
Metabolic acidosis.
What is tachypnea, dyspnea, hyperpnea, abdominal breathing?

                           NORMAL VITAL SIGN VALUES FOR VARIOUS SPECIES*

species                                temperature                           pulse                      respiration
                                          F                    C

dog                            101.3 +/- 0.5        38.5            70 -120 (180+toys)             15-30

cat                             100.7 +/- 0.5         38.3                    100-240                       20-30

horse                         100.9 +/- 0.5         37                        28-42                          8 -15

cow                            101.5 +/- 0.5        38.5                        60                               30

sheep                         102.6 +/- 0.5        39.5                        75                               20

*THESE VALUES VARY SLIGHTLY IN DIFFERENT TEXTBOOKS

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There are three other evaluations that can be done quickly to help determine the physical status of a patient: 
Mucous membrane color
Capillary refill time (CRT)
Hydration

Color
Traditionally color is checked at the gums, but other mucous membranes can be used.
The color helps evaluate the blood perfusion ( function of the cardiovascular system) and respiratory function (oxygenation) as reflected in the peripheral tissue.

Explain why the gums are pink
What are mucous membranes? Where else are they found?

The different "shades of color" of the mucous membranes can provide information about the status of the patient, here are some conditions associated with certain colors of mucous membranes.
Pale: anemia, often due to blood loss or shock
Blue: cyanosis, due to a lack of oxygenation caused by various problems primarily associated with respiratory system.
Yellow: jaundice or icterus, can reflect either liver pathology or hemolysis of circulating red blood cells
Bright red: hyperemic, may reflect compensatory phase of shock or sepsis.
Muddy: membranes have abnormal "grayish" tinge caused by shock, heart failure, or sepsis
Brown: membranes appear brown tinged due to methemoglobinia, caused most often by poisoning from toxins such as Tylenol (in cats).
Pink: normal

Capillary Refill Time (C.R.T.)

Capillary refill time evaluates the blood flow to mucous membranes this aids in evaluation of cardiac function and vascular resistance.
The C.R.T. is checked by pressing on the gums with a finger or thumb firmly to blanch the area then measuring the time it takes to return to normal color.
The normal C.R. T. is considered 1 - 2 seconds.

Hydration

Dehydration is the loss of body fluid. The body is composed of  about 70 -80% water in the normal adult animal,  even more in the young. This fluid is found inside the cells (intracellular) and outside the cells (extracellular).  
Only a few percentage points loss of fluid is life threatening. 
At about 12% loss of body fluids death occurs.
The actual percentage of dehydration is difficult to determine, it can be estimated by the packed cell volume  (PCV) and by checking the skin turgor.

Skin turgor refers to the elasticity and "feel" of the skin. As the animal becomes dehydrated the skin becomes less elastic, it does not snap back when pinched, and is described "as doughy".  When  dehydration is severe the skin actually tents (remains in the tented position for seconds before flattening out) when pinched.
Other ways to determine dehydration include checking mucous membrane (gums) for moistness and noting if the eyes are sunken (this is a grave sign!)

Evaluating levels of dehydration
slight to moderate = 3 - 9% "doughy skin "
severe = 9 -12% tenting of skin ( 2 seconds or more to return to normal position) eyes sunken and dry gums, patient maybe near death

Basic Patient Evaluation

An important part of animal care is recognition of the signs of illness, the sooner the illness is recognized the better chance for recovery. There are major differences in normal behavior and signs of illness between species.
There are four basic parameters that can be used to evaluate animals that do not involve any special knowledge. An owner should be familiar with their own pet to accurately evaluate these parameters. An owner can be questioned about these signs to help determine how serious the condition is and if emergency care is needed.
 
1) Abnormal appearance: Including changes in expression: such as dull eyes, rough or soiled coat, lameness, odor, scratching, or scooting.

2) Change in activity level: Including a decrease in activity, unusual activity, vomiting, whimpering or even an unexpected increase in activity, especially.

3) Appetite: Increase or decrease

4) Elimination: Increase or decrease in defecation or urination, change in consistency or odor or straining to eliminate

Livestock and exotics:
Illness in these animals can be very difficult to detect in the early stages, especially when they are in a herd, group or flock. It is their instinctive behavior to remain with the group, since falling behind means risking being detected by a predator.

Good herdsmen/women can spot early abnormal behavior which other people would miss such as a normally gregarious animal standing slightly away from the group, a dull eye, a lowered head,  a soiled hock, tail, feathers (a sign of diarrhea) or a small puncture wound.

Horses
Horses that are well socialized and handled daily are easier to monitor for illness than livestock. Most horse owners are very aware of changes in eating and behavior.  But horses can suffer from acute life threatening diseases such as colic and founder and should be monitored frequently, especially in new situations or during dietary changes.
What is colic and founder/laminitis?

Textbook Assignment: Please read Clinical Textbook for Veterinary Technicians by Bassert and McCurnin
pages 780-788
Please cut and paste these questions into a word document then answer them in word to the instructor. ________________________________________________________________________________________
 

__________________________________________________________________________________________

Answers to italized questions.
What is the purpose of the string? 
So it can be pulled out if "swallowed" by the rectum

Which scale is used most commonly in the Unites States?  Fahrenheit

If a mercury thermometer breaks on the examine room table or floor should the client pick it up?   
NO  Why?  it is toxic!


Are there differences in the pulse rates between young and old animals? 
 younger = faster

What is tachypnea, (fast breathing) 
dyspnea, (difficult)  
hyperpnea, (forced, hard)  
abdominal breathing? (using abdominal muscles to assist in breathing, see lots of movement of the abdomen during breathing)

Explain why the gums are pink.  
adequate vascularity of gums

What are mucus membranes?  Where else are they found?
The epithelia opening of the body, gums, conjunctiva, rectum etc.  

What is colic and founder/laminitis?
Colic is a general term describing abdominal pain, in horses it can be caused by many things including excess gas, twisted intestines, obstructed intestines etc. It can cause death if not treated.

Laminitis is an inflammation of the laminae of the hoof. It can also be very serious and cause great pain and the horse to loose function of the hooves.

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