Comprehensive Study Guide on Pulse and Respiratory Vital Signs

Normal Pulse Ranges and Developmental Variations

• Infants and Babies: Normal heart rates for babies range from $100$ to $160\,\text{beats per minute}$. Their hearts naturally beat significantly faster than those of adults.
• Adults: The standard normal range for an adult at rest is $60$ to $100\,\text{beats per minute}$.
• Athletes: Individuals who are physically fit or play sports often exhibit a lower resting heart rate, frequently in the $50\text{s}$ or even high $40\text{s}$. This occurs because the heart muscle is conditioned to be more efficient, allowing it to maintain circulation with fewer beats at rest.

Factors Influencing Pulse

• Body Positioning: Pulse rates can vary significantly depending on whether a patient is lying down, sitting, or standing.
• Age: Pulse rates change across the lifespan, with distinct norms for newborns, toddlers, young adults, and older adults.
• Activity Levels: Physical exertion increases the heart rate, while long-term athletic training lowers the resting heart rate.
• Health Conditions: Various underlying medical issues can cause the heart rate to fluctuate outside normal ranges.
• Body Temperature: As body temperature increases (such as during a fever), the heart rate typically increases as well.

Quantitative and Qualitative Pulse Assessment

When assessing a pulse, three primary characteristics must be evaluated:

• Rate: The specific number of beats counted per minute ($\text{BPM}$).
• Rhythm: This refers to the regularity of the beats.
  • Normal Sinus Rhythm: This is the clinical term for a heart rate beating at a normal, consistent interval.
  • Observation: The rhythm should feel consistent ($\text{bum, bum, bum}$). It should not be irregular, such as a pattern where there are several quick beats followed by a pause.
• Volume and Strength: This refers to the force of the blood against the arterial wall.
  • Thready/Weak: A pulse that is difficult to feel, suggesting a potential medical issue.
  • Bounding: A pulse that feels exceptionally strong or forceful against the fingers, often seen after intense exercise or due to specific heart conditions.

Methods of Assessment

• Palpation: The act of feeling the pulse using the fingers (specifically the index and middle fingers, never the thumb).
• Auscultation: The act of listening to the heart sounds using a stethoscope.
• Doppler Assessment: Using a Doppler device (ultrasound) to hear pulses that may be difficult to palpate. This is commonly used for fetal heart monitoring by placing the device on the mother's abdomen.

Anatomical Locations of Pulse Sites

To perform a complete "head-to-toe" assessment, one must be able to locate the following arteries:

• Temporal Artery: Located on the temple, aligned with the top of the ear where the hair line meets the skull.
• Carotid Artery: Located in the neck, in the groove between the trachea and the sternocleidomastoid muscle.
  • Safety Warning: Never palpate the carotid arteries bilaterally (both sides at once). Doing so can cut off circulation to the brain and cause the patient to pass out. These must be assessed unilaterally.
• Brachial Artery: Located on the inner part of the arm (antecubital fossa). This is the primary site used for assessing blood pressure.
• Radial Artery: Located on the thumb side of the wrist, aligned with the radial bone. This is the most common site for routine pulse checks.
• Femoral Artery: Located in the groin area. It is often more pronounced when the patient is lying down.
• Popliteal Artery: Located behind the knee, typically slightly toward the inner corner of the leg.
• Posterior Tibial Artery: Located on the inner side of the ankle, just below the medial malleolus (the protruding ankle bone).
• Dorsalis Pedis Artery: Located on the top of the foot, in the groove between the big toe and the second toe.

Pulse Strength Scale

When documenting the strength of a pulse, the following numerical scale is used:

• $0$: Pulse is absent (cannot be felt).
• $1+$: Pulse is weak, thready, and barely perceptible.
• $2+$: Normal pulse; this is the expected finding for a healthy individual.
• $3+$: Increased or strong pulse.
• $4+$: Bounding pulse; the heart is pumping forcefully against the artery.

Tachycardia and Bradycardia

• Tachycardia: A heart rate that exceeds $100\,\text{beats per minute}$.
  • Common Causes: Exercise, anxiety attacks, stress, caffeine, nicotine, and certain medications like albuterol (used for asthma).
• Bradycardia: A heart rate that is less than $60\,\text{beats per minute}$.
  • Common Causes: High physical fitness, congenital heart abnormalities (present at birth), heart failure, heart muscle damage (e.g., from a previous heart attack), and hypothyroidism.
  • Hypothyroidism vs. Hyperthyroidism: In hypothyroidism, metabolic processes slow down, resulting in weight gain and a lower heart rate. In hyperthyroidism, metabolic processes increase, leading to an increased heart rate.
  • Symptoms of Bradycardia: Dizziness (caused by insufficient blood reaching the brain), fatigue, shortness of breath, chest pain, and confusion.

Dysrhythmia and Pulse Deficit

• Dysrhythmia: An irregular heart rhythm where the heart may skip beats or have extra beats. This may sometimes be associated with a heart murmur (a "whooshing" sound caused by turbulent blood flow).
• Pulse Deficit: A condition where the heart's contractions are not strong enough to produce a palpable peripheral pulse. Finding a pulse deficit requires two nurses:
  • Nurse 1: Auscultates the apical pulse (the apex of the heart).
  • Nurse 2: Palpates the radial pulse simultaneously.
  • Procedure: Both nurses count the heartbeats for one full minute. The radial rate is subtracted from the apical rate to determine the deficit. ($\text{Apical Rate} - \text{Radial Rate} = \text{Pulse Deficit}$).
  • The Apical Pulse: This is the most accurate pulse site, located at the apex (lower left corner) of the heart. Anatomically, it is found at the midclavicular line at the fifth intercostal space (the space between the fifth and sixth ribs).

Respiratory Assessment and Physiology

• Mechanics of Breathing:
  • The Diaphragm: The primary muscle for breathing, separating the chest cavity from the intestines. During inhalation, the diaphragm moves down to allow the lungs to expand. During exhalation, it moves back up.
  • Intercostal Muscles: Muscles between the ribs that assist in chest expansion.
  • One Breath: Defined as one full inhalation plus one full exhalation.
• Normal Adult Range: $12$ to $20\,\text{breaths per minute}$.
  • Documentation Note: Avoid using "BPM" for respiration to prevent confusion with "beats per minute." Use "breaths per minute."
• Terminology:
  • Tachypnea: Fast breathing, defined as more than $20\,\text{breaths per minute}$.
  • Bradypnea: Slow breathing, defined as fewer than $12\,\text{breaths per minute}$.
  • Ventilation: The mechanical process of moving air in and out of the lungs.
  • Diffusion: The passive movement of oxygen and carbon dioxide at the level of the alveoli (the grape-like air sacs at the end of the bronchioles).
  • Perfusion: The flow of blood through the lung capillaries to facilitate gas exchange.
  • Apnea: The complete absence of breathing. This is common in conditions like sleep apnea, where breathing stops periodically during sleep.

Factors Affecting Respiration

• Age: Younger children and babies have higher respiratory rates than adults.
• Medications: Opioids (such as morphine) act as central nervous system depressants and can cause respiratory depression, potentially leading the patient to stop breathing.
• Brain Injury: Since the brain controls the drive to breathe, injuries to the head can significantly alter respiration.
• Anemia and Illness: Conditions that impair the transport of oxygen throughout the body will affect how a person breathes.
• Hyperventilation: This occurs when a person breathes too fast and exhales carbon dioxide ($CO_2$) too quickly. This can lead to fainting. A common remedy is breathing into a brown paper bag to re-inhale the lost $CO_2$.

Clinical Technique for Respiration

• Patient Education: Never tell a patient you are counting their respirations. Breathing is often under voluntary control; if patients know they are being watched, they will change their natural breathing pattern.
• Best Practice: Many clinicians maintain their hand on the patient's radial pulse after they have finished counting the heart rate, but then shift their focus to observing the rise and fall of the chest.