Table of Contents
What is Meaning of Physiological Assessment ?
A process in nursing where a patient’s overall appearance and physical condition are evaluated to assess their health status. This includes checking for normal development, nutritional status, signs of illness (like jaundice or cyanosis), and the presence of any missing or artificial body parts.
VITAL SIGNS
NORMAL, ABNORMAL CHARACTERISTICS, FACTORS INFLUENCING THE VARIATIONS
Definition:
Vital Signs:
Vital signs are key indicators of a person’s overall health, comprising temperature, pulse, respiration, and blood pressure. These measurements reflect the functioning of vital organs and can reveal deviations from normal body functions, indicating potential health issues.
Important Points:
- Vital Signs Include: Temperature, pulse, respiration, and blood pressure.
- Normal Ranges in Adults:
- Temperature: 98.6°F (37°C)
- Pulse: 70-80 beats per minute
- Respiration: 16-20 breaths per minute
- Blood Pressure: 120/80 mm Hg
- Significance: Vital signs are governed by vital organs and detect deviations from normal body functions.
- Health Indicators: Variations can indicate problems like oxygen depletion, electrolyte imbalance, or infections.
- Diagnosis and Treatment: Observations help in diagnosing diseases and assessing the effectiveness of treatments.
- Emotional Impact: A patient’s emotional state can also affect vital sign readings.
Definition: Temperature
Body Temperature:
Body temperature is the degree of heat maintained by the body, representing the balance between heat produced and heat lost. It is regulated by thermogenesis (heat production) and thermolysis (heat loss), primarily controlled by the hypothalamus.
Important Points:
- Definition: Body temperature = Heat produced – Heat lost.
- Regulation Mechanisms:
- Thermogenesis: Chemical regulation through heat production.
- Thermolysis: Physical regulation through heat loss.
- Control Center: The hypothalamus in the brain regulates body temperature by responding to thermal receptors that detect temperature changes.
Physiology of Body Temperature:
- Heat Production:
- Metabolism:
- Carbohydrates: 4 calories/gram
- Proteins: 4 calories/gram
- Fats: 9 calories/gram
- Exercise: Increases heat production due to faster metabolism and energy release from glycogen.
- Heat Loss Mechanisms:
- Through the Skin:
- Vasodilation increases blood flow to the skin, leading to heat loss via:
- Conduction: Heat transfer through direct contact.
- Convection: Heat transfer through moving air or liquid.
- Radiation: Heat transfer through electromagnetic waves (60% of heat loss).
- Evaporation: Heat loss through sweating (540 calories/gram of water).
- Through the Lungs:
- Inhaled air warms to body temperature; approximately 300 ml of water vapor is lost daily.
- Through the Kidneys:
- Urine absorbs heat from the body, leading to heat loss during excretion.
- Through the Bowels:
- Feces absorb heat, resulting in heat loss during defecation.
Characteristics of Normal and Abnormal Temperature
Normal Variation in Body Temperature:
- Normal Range: 97°F to 99°F (36.1°C to 37.2°C).
- Factors Influencing Variation:
- Time of Day: Lower in the morning, higher in the evening.
- Menstrual Cycle: Sudden drop during menstruation; rises after ovulation.
- Age: Younger individuals tend to have higher temperatures than older adults.
- Measurement Site:
- Rectal: 99.6°F (37.5°C) – highest.
- Oral: 98.6°F (37°C).
- Axillary: 97.6°F (36.4°C) – lowest.
Alterations in Temperature:
A. Pyrexia (Fever):
- Body temperature rises above normal due to an increased regulatory set-point (normal range: 36.5°C to 37.5°C or 98°F to 100°F).
- Common types:
- Continuous Fever: Elevated temperature remains constant (e.g., pneumonia, typhoid).
- Remittent Fever: Elevated temperature fluctuates but remains above normal (e.g., infective endocarditis).
- Intermittent Fever: Fever present for specific periods (e.g., malaria).
- Relapsing Fever: Alternating short fever and normal temperature periods.
- Fever Spike: Rapid temperature rise to fever level, then back to normal within hours.
- Classification of Fever:
- Low Pyrexia: 99-100°F (37.2-37.8°C).
- Moderate Pyrexia: 100-103°F (37.8-39.4°C).
- High Pyrexia: 103-105°F (39.4-40.6°C).
- Hyperpyrexia: Above 105°F.
- Subnormal Temperature: Below 95°F (35°C).
- Irregular Fever: Cannot be classified under known types.
B. Hypothermia:
- Core body temperature falls below 95°F (35°C).
C. Hyperpyrexia:
- Very high fever (above 106°F or 41.5°C) caused by infection or central nervous system issues.
D. Hyperthermia:
- Body temperature rises to 105°F (40.6°C) or higher, with an unchanged regulatory set point.
E. Heat Stroke:
- Severe hyperthermia with body temperature above 104°F (40°C).
Factors Affecting Body Temperature
- Fluid and Food Intake:
- Food provides energy, and metabolism generates heat. Prolonged fasting can lower body temperature.
- Stress:
- Physical and emotional stress increases body temperature due to hormonal and neural stimulation, leading to increased metabolism.
- Age:
- Infants and children experience rapid temperature changes. Older adults have lower body temperatures due to loss of subcutaneous fat.
- Gender:
- Women experience greater fluctuations in body temperature due to hormonal changes, particularly during the menstrual cycle.
- Hormonal Levels:
- Hormonal variations, especially during menstruation and ovulation, can affect body temperature.
- Exercise:
- Increased muscle activity raises blood supply and metabolism, causing an increase in heat production. Prolonged exercise can temporarily raise body temperature up to 105.8°F (41°C).
- Circadian Rhythms:
- Body temperature follows a 24-hour cycle, being lower in the morning and peaking between 4 PM and 7 PM.
- Environmental Factors:
- Exposure to hot or cold environments can influence body temperature. It’s essential to wait at least 15 minutes after activities like bathing, drinking hot or cold beverages, or smoking to obtain a reliable temperature reading.
- Illness, Injury, or Infection:
- Pyrogens can alter the hypothalamic set point, causing fever. The body’s defense mechanisms activate during infections, raising temperature.
- Dehydration:
- Conditions like diarrhea and vomiting can lead to lower body temperature if not managed properly.
- Fluid Loss:
- Sweating and perspiration lower body temperature through evaporation.
- Clothing:
- Wearing warm clothes in cold weather helps maintain normal body temperature, while exposure to extreme temperatures can cause variations.
- Drugs and Alcohol:
- Antipyretics (e.g., aspirin) lower elevated body temperature, while substances like alcohol and some medications may raise or lower temperature readings.
Assessing Temperature
1. Clinical Thermometer:
A clinical thermometer is a specialized instrument designed to measure body temperature. It is available in both Fahrenheit and Celsius scales.
Parts:
- Bulb:
- Contains mercury and is sensitive to temperature changes.
- Different sizes and shapes exist; oral thermometers have long, slender bulbs, while rectal thermometers have short, fat bulbs, often with colored bulbs for easy identification.
- Stem:
- A hollow inner tube where mercury rises or falls with temperature changes.
- The graduated scale on the stem ranges from 35°C (95°F) to 43.3°C (110°F).
Care of Thermometers:
To prevent damage to thermometers, follow these guidelines:
- Shaking Down Mercury:
- Grasp the upper end of the stem, never hold the bulb. Shake down the mercury with a quick wrist movement.
- Avoid letting the thermometer fall or strike anything.
- Cleaning:
- Do not wash with hot water; this can expand the mercury and break the thermometer.
- Rinse with clean water, dry the bulb and stem, and store with the bulb down on a smooth surface (e.g., cotton).
- Usage:
- Do not place the thermometer in the mouth of a person who cannot understand instructions or hold it in place.
- Disinfection:
- Wash with soap and water and disinfect with a suitable solution. Disinfectant Strength Time Dettol 1:40 5 mins Savlon 1:20 5 mins Lysol 1:40 3 mins Fairgenol 1:40 5 mins
Celsius and Fahrenheit Scales:
Body temperature can be recorded in both Celsius and Fahrenheit. To convert between the two scales, use the following formulas:
To Convert Fahrenheit to Celsius:
Formula : C = (F-32) * 5 / 9
To Convert Celsius to Fahrenheit:
Formula : F = C * 9 / 5 + 32
2. Electronic or Digital Thermometer
Electronic thermometers are designed to measure body temperature conveniently, safely, quickly, and accurately. They are precise, easy to read and use, and do not contain mercury.
Common Sites for Taking Body Temperature:
To obtain an accurate measurement, the bulb of the thermometer must be surrounded by body tissue and in proximity to blood vessels. Contact with clothing, air, or moisture can affect the reading. Common sites include:
- Mouth
- Axilla (Armpit)
- Groin
- Rectum
- Vagina
A. Temperature by Mouth:
Advantages:
- Good blood supply under the tongue allows for an accurate reading.
- Reduced chance of the bulb coming in contact with outside air.
- Easy to hold under the tongue, minimizing the risk of dropping.
- No need for privacy.
Disadvantages:
- The nurse may not know the thermometer’s exact position; incorrect placement could lead to false readings.
- Children or unconscious individuals may bite the thermometer, risking breakage.
- Inadequately cleaned thermometers pose a risk of cross-infection.
- Residual disinfectant may affect taste if not properly rinsed.
Contraindications:
- Clients who are extremely nervous, delirious, or unable to follow instructions.
- Patients experiencing convulsions.
- Mouth breathers.
- Injuries or inflammation in the mouth.
- Weak patients unable to hold the thermometer.
- Children under six years old.
- Temperature should not be taken within 15 minutes after eating, drinking, smoking, or chewing.
B. Temperature by Axilla:
Advantages:
- Less discomfort for the client.
Disadvantages:
- Moisture from perspiration can lead to false readings.
- Incorrect placement can result in exposure to air or clothing, affecting accuracy.
Indications:
- Oral inflammation or jaw surgery.
- Clients who cannot breathe through the nose (mouth breathers).
- Irrational clients.
Contraindications:
- Any surgery or lesions in the axilla.
C. Temperature by Rectum:
Advantages:
- The rectal method is highly reliable, as it has a rich blood supply and is not influenced by external air.
- Correct positioning yields accurate readings.
Disadvantages:
- Requires client privacy.
- Needs lubrication for the bulb.
- Potential for soiling the nurse’s hands.
- Fecal matter can lead to false readings.
Indications:
- When oral and axillary methods are contraindicated.
Contraindications:
- Patients with rectal surgery or inflammation.
- Patients experiencing diarrhea.
- When the rectum is impacted with fecal matter.
- Patients undergoing treatments like bowel washes or enemas.
Frequency of Taking Temperature in Hospitals:
- For stable patients, temperature is typically taken in the morning and evening.
- Patients who are acutely ill, experiencing high fever, or post-operative may require temperature checks every four hours or more frequently.
- If temperature is taken rectally or axillary, it should be clearly documented in the patient’s chart.