5.3 Patient Vital Signs Assessment (TPR)

5.3 Patient Vital Signs Assessment (TPR)

A vital signs assessment is a quick, objective evaluation of a patient's core physiological functions. Assessing vital signs is a daily, fundamental task for veterinary assistants. The primary parameters are Temperature, Pulse, and Respiration (TPR), which are evaluated alongside Mucous Membrane (MM) Color and Capillary Refill Time (CRT) to assess cardiovascular and respiratory status.

Rectal Temperature (T)

Body temperature is a key indicator of systemic inflammation, infection, thermoregulatory capacity, and metabolic activity. Rectal measurement is the clinical standard in small animal veterinary medicine.

Normal Ranges and Abnormalities

• Normal Range: The normal rectal temperature for both dogs and cats is 100.0°F to 102.5°F (37.8°C to 39.2°C).
• Hyperthermia and Pyrexia (Fever): A temperature above 103.0°F is abnormal.
  • Fever (Pyrexia): A biological response to infection, inflammation, or immune-mediated disease. The body's internal thermostat is reset higher.
  • Hyperthermia: A non-infectious rise in body temperature, often due to environmental heat (heatstroke), exercise, or stress/excitement (e.g., a nervous cat in the clinic).
• Hypothermia: A temperature below 99.0°F is abnormal. It is commonly caused by anesthesia, shock, cardiovascular failure, systemic illness, or prolonged exposure to cold temperatures.

Equipment and Technique

1. Prepare the Thermometer: Use a digital thermometer designated for rectal use. Ensure the probe cover is clean.
2. Lubrication: Apply a small amount of water-soluble lubricating jelly to the tip. Inserting a dry thermometer is painful and can tear the rectal mucosa.
3. Restraint: Have an assistant hold the dog or cat in a standing or sitting position. Gently lift the tail at the base (do not pull or bend the tail harshly).
4. Insertion: Gently insert the tip into the rectum with a slow twisting motion.
   • For cats and small dogs: insert approximately 1 inch.
   • For medium and large dogs: insert 1 to 2 inches.
   • Tip: Direct the thermometer slightly to the side to ensure the tip makes contact with the rectal wall rather than being embedded in fecal matter, which can skew the reading lower.
5. Reading and Sanitation: Hold the thermometer until it beeps. Gently remove it, wipe the probe clean with an alcohol-soaked gauze sponge, record the temperature, and return the thermometer to its charger or storage.

Pulse and Heart Rate (P)

Heart rate (HR) is the number of cardiac contractions per minute, while pulse rate is the physical pulsation of an artery as blood is pumped through it by the heart.

Locations for Assessment

• Auscultation: Heart rate is measured using a stethoscope placed on the left side of the chest wall, just behind the elbow (the cardiac apex).
• Palpation: The pulse rate is most commonly palpated at the femoral artery, located on the medial (inner) aspect of the thigh in the groin area.
• Technique: Use the pads of your index and middle fingers to feel the femoral artery. Never use your thumb, as you may feel your own pulse. Count the beats for 15 seconds and multiply by 4 (or 10 seconds and multiply by 6) to determine the beats per minute (bpm). If the rhythm is irregular, count for a full 60 seconds.
• Pulse Deficit: Auscultate the heart while simultaneously feeling the femoral pulse. They should occur in a 1:1 ratio. If you hear a heartbeat but do not feel a corresponding pulse, a pulse deficit exists, indicating a cardiovascular issue (such as an arrhythmia) that must be reported to the veterinarian.

Normal Ranges

• Dogs: 60 to 180 beats per minute (bpm). Heart rates in dogs vary by body size:
  • Large/Giant breeds: 60 - 100 bpm.
  • Medium breeds: 80 - 120 bpm.
  • Small/Toy breeds: 100 - 160/180 bpm.
  • Puppies: Up to 220 bpm.
• Cats: 140 to 220 beats per minute (bpm). Cat heart rates are highly sensitive to stress. A cat with a heart rate below 140 bpm in a clinic setting is abnormal and may be in cardiovascular shock or suffering from systemic disease.

Respiration Rate (R)

Respiration rate (RR) is the number of breaths (one inhalation and one exhalation equals one breath) per minute.

Assessment and Ranges

• Technique: Observe the rising and falling of the chest wall, or place a hand gently near the chest or flank. Count the breaths for 15 or 30 seconds and multiply to find the breaths per minute. Assess the respiratory rate when the animal is calm and not panting, sniffing, or purring (purring makes counting respiration difficult).
• Normal Ranges:
  • Dogs: 10 to 30 breaths per minute.
  • Cats: 20 to 30 breaths per minute (up to 40 is sometimes acceptable if the cat is moderately stressed, but should be monitored).
• Abnormal Patterns:
  • Tachypnea: An abnormally rapid breathing rate.
  • Dyspnea: Difficult or labored breathing, often characterized by abdominal effort, extended neck, wide elbows, and nostril flaring.
  • Panting: Normal cooling mechanism in dogs, but open-mouth breathing in cats is a life-threatening emergency indicating severe respiratory or cardiac failure.

Mucous Membrane (MM) Color and Capillary Refill Time (CRT)

Mucous membranes and capillary refill time are evaluated together to assess oxygenation and blood circulation (perfusion).

Mucous Membrane Color

Inspect the mucous membranes by lifting the patient's upper lip to examine the gums (gingiva). If the gums are pigmented black or dark brown, check the conjunctiva of the eyelids, the inside of the vulva, or the prepuce.

Capillary Refill Time (CRT)

CRT measures how quickly blood returns to the capillary bed after it has been compressed. It is a direct indicator of tissue perfusion and hydration status.

• Technique: Press your finger firmly against a pink area of the patient's gums until the tissue turns white (blanches). Release the pressure and count the seconds it takes for the tissue to turn pink again.
• Normal Range: Less than 2 seconds (< 2s).
• Prolonged CRT: Greater than 2 seconds (> 2s). This indicates poor circulation, dehydration, low blood pressure, or cardiovascular shock.
• Rapid CRT: Less than 1 second (< 1s). This can indicate high cardiac output, often associated with early sepsis, heatstroke, or systemic inflammation.