Nursing Lecture: Vital Signs and Patient Assessment

Fever and Pyrexia

  • Terminology and Definitions

    • Pyrexia: The medical term for fever.
    • Febrile: A state in which the patient has a fever.
    • Afebrile: A state in which the patient is without a fever (indicated by the prefix "a-").
    • Diaphoresis: Excessive sweating, often associated with the resolution of a fever or heat-related illness.

  • Physiology of Fever

    • Pyrogens: Substances (such as bacteria) that act to elevate the body temperature.
    • Hypothalamus: The brain region responsible for temperature regulation. Rapid adjustments or high temperatures in this area can trigger febrile seizures.
    • Febrile Seizures: These occur most frequently in children between the ages of 6 months6 \text{ months} and 6 years6 \text{ years}.

  • Management and Interventions

    • Fluid Management: Water is the preferred fluid for rehydration. Gatorade, Powerade, and Pedialyte are options, but water is best to avoid the high salt or potassium content found in some sports drinks.
    • Antipyretics: Medications used to reduce fever.
    • Cooling Blankets: Used for patients with extremely high temperatures, such as those suffering from heat exhaustion or heat stroke.
    • Environment: Keeping the patient in a cold environment with minimal clothing can help regulate temperature.
    • Shivering: An involuntary muscle response to cold that consumes a significant amount of energy.

Heat and Cold Related Alterations

  • Heat Exhaustion

    • Characterized by significant diaphoresis (sweating) and a resulting electrolyte imbalance.
    • Common in athletes, children playing outside, or people working outdoors in the summer.
    • Treatment involves moving the individual to a cooler location and rehydrating them.

  • Heat Stroke

    • A more severe condition characterized by hot, dry skin, delirium, and convulsions.

  • Hypothermia

    • Symptoms include uncontrolled shivering, memory loss, and a decrease in heart rate, respiratory rate, and blood pressure.
    • Cyanosis: The skin may turn a blue color due to lack of oxygenation/circulation.
    • Treatment interventions: Skin-to-skin contact, drying the patient, and covering the head to prevent heat loss.

  • Frostbite

    • Localized cold injury involving peripheral circulatory damage.
    • Common sites: Fingertips, toes, ears, and the nose.
    • Physiology: Tissues crystallize underneath the skin, which may turn black or white. This often results in permanent tissue damage and may require amputation due to the lack of blood flow.

Pulse Assessment and Physiology

  • Circulatory Indicators

    • Pulse: An indirect indicator of circulatory status.
    • Heart Rate: A direct indicator of circulatory status.
    • Stroke Volume: The volume of blood that enters the heart (and is ejected) with each squeeze or contraction.
    • Cardiac Output: The volume of blood pumped by the heart in one minute. It is calculated as:     CardiacOutput=StrokeVolume×HeartRateCardiac Output = Stroke Volume \times Heart Rate

  • Assessment Technique

    • Use a watch with a second hand.
    • Use the tips (not the pads) of the three middle digits.
    • Do not press too hard, as this can obliterate the pulse.
    • For a regular pulse, count for 30 seconds30 \text{ seconds} and multiply by 22. If the pulse is irregular, you must count for a full minute.

  • Pulse Sites

    • Temporal: Located on the side of the head.
    • Carotid: Located near the trachea. Assess only one side at a time to prevent cutting off blood flow to the brain, which could cause the patient to pass out.
    • Brachial: Found in the antecubital fossa; move from the middle toward the medial side (toward the body). This is where the diaphragm of the stethoscope is placed for blood pressure measurement.
    • Radial: Located on the side of the wrist near the thumb.
    • Ulnar: Located on the side of the wrist near the pinky; often fainter than the radial pulse.
    • Femoral: Deep pulse in the groin area; often requires significant pressure to palpate and is used frequently during CPR.
    • Dorsalis Pedis: Located on the top of the foot.
    • Apical Pulse: Located at the fourth or fifth intercostal space at the left midclavicular line (under the breast tissue in females, or near the nipple line in males).
    • This site is the PMI (Point of Maximal Impulse), where the heart sounds (S1,S2S_1, S_2) are loudest.
    • Use the apical pulse for a full minute if the radial pulse is irregular, or if the patient is on medications like beta-blockers that affect heart rate.

  • Pulse Findings and Ratings

    • Normal Range: 60 to 100 beats per minute (bpm)60 \text{ to } 100 \text{ beats per minute (bpm)} for an adult.
    • Tachycardia: An increased heart rate above 100 bpm100 \text{ bpm}.
    • Bradycardia: A decreased heart rate below 60 bpm60 \text{ bpm}.
    • Grading Scale:
    • +2+2: Normal, expected pulse.
    • +3+3: Full or bounding pulse (often seen after exercise or caffeine intake).
    • Equality: Pulses should be symmetric when compared on both sides of the body.

Respirations and Oxygenation

  • Physiology of Breathing

    • Ambient Air: The air around us that is inhaled; it is not pure oxygen.
    • Breathing is an involuntary, passive process controlled by the level of carbon dioxide (CO2CO_2) in the blood.
    • Ventilation: The movement of gases in and out of the lungs.
    • Diffusion: The exchange of respiratory gases in the lungs.
    • Perfusion: The distribution of red blood cells to and from the pulmonary capillaries.

  • Assessment Technique

    • One Respiration: Consists of one full inhale (chest rise) and one full exhale (chest fall).
    • Normal Range: 12 to 20 breaths per minute12 \text{ to } 20 \text{ breaths per minute} for an adult.
    • Method: Observe the chest or abdomen. It is best to count for 30 seconds30 \text{ seconds} immediately after taking the pulse while still holding the patient's wrist so they do not consciously alter their breathing pattern.

  • Oxygen Saturation (SpO2SpO_2)

    • Measured via pulse oximetry to assess tissue perfusion.
    • Normal Range: 95% and above95\% \text{ and above}.
    • Medical Emergency: Any value below 90%90\%.

  • Alterations in Breathing Patterns

    • Eupnea: Normal breathing.
    • Tachypnea: Increased respiratory rate.
    • Bradypnea: Decreased respiratory rate.
    • Apnea: The cessation of breathing.
    • Hyperpnea (Kussmaul): Labored breathing with increased depth and a rate typically greater than 2020. Often seen in patients with high ketones (sugar issues) as the body tries to "breathe off" acids.
    • Cheyne-Stokes: Irregular breathing pattern characterized by alternating periods of apnea and hyperventilation; typically seen at the end of life (hospice).
    • Shallow Breathing: Limited rise and fall of the chest, often due to pain or injury; results in poor perfusion.

Blood Pressure Assessment

  • Physiological Components

    • Systolic: The top number; represents the pressure when the ventricles contract (the "squeeze").
    • Diastolic: The bottom number; represents the pressure when the ventricles relax and refill with blood.
    • Pulse Pressure: The difference between the systolic and diastolic numbers (Systolic−DiastolicSystolic - Diastolic).
    • Normal BP: Less than 120/80 mmHg120/80 \text{ mmHg}.

  • Factors Influencing Blood Pressure

    • Hypertension: High blood pressure. It is a major risk factor for death from stroke and heart attack.
    • Hypotension: Low blood pressure, typically a systolic of 90 mmHg90 \text{ mmHg} or below. Can cause dizziness and lightheadedness.
    • Genetics/Ethnicity: African American males are at the highest risk for hypertension, followed by African American females.
    • Modifiable Factors: Smoking (nicotine causes vasoconstriction), diet (high fat intake leads to plaque buildup), and activity levels.
    • Circadian Rhythm: Blood pressure varies daily; it is usually lower in the early morning and peaks in the late afternoon/evening.
    • Plaque/Atherosclerosis: Fat buildup in vessels increases pressure (like a clogged hose). Significant blockage leads to a Myocardial Infarction (heart attack).

  • Measurement and Equipment

    • Sphygmomanometer: The blood pressure cuff.
    • Stethoscope Tools: The Diaphragm is the large side of the chest piece, and the Bell is the smaller side. Earpieces should face forward (toward the patient) to enter the ear canal correctly.
    • Procedure:
    • Inflate the cuff to approximately 30 mmHg30 \text{ mmHg} above the patient's normal systolic pressure.
    • Deflate slowly while watching the dial.
    • The first sound (Korotkoff sound) heard is the Systolic pressure.
    • The final sound heard before silence is the Diastolic pressure.
    • Lab Standards: Students must be accurate within 4 mmHg4 \text{ mmHg} of the actual reading during check-offs.