Vital Signs : Respiration & Oxygen Saturation

Inspiration

The active intake of air by the lungs to oxygenate body tissues and support cellular function.

Expiration

The expulsion of carbon dioxide, the waste product of gas exchange, from the lungs.

Anatomical site and mechanism of pulmonary gas exchange

Occurs at the alveoli and pulmonary capillaries via diffusion.

Diffusion: Movement of particles from an area of higher concentration to lower concentration. In the lungs, O₂ moves from the alveoli into the pulmonary capillaries, while CO₂ moves from the pulmonary capillaries into the alveoli.

Muscular mechanics during inspiration

Contraction of the diaphragm and intercostal muscles pulls the ribs upward and outward to expand the thoracic cavity.

Muscular mechanics during expiration

Relaxation of the diaphragm and intercostal muscles allows the thoracic cavity to return to a position of rest.

Rationale for unobtrusively counting respirations without informing the client

Prevents the client from consciously or unconsciously altering their natural breathing rate or pattern.

Assessment duration for counting respiratory rate in healthy vs. ill clients

Observe or auscultate for $30\,\text{seconds}$ and multiply by $2$ for healthy clients; count for a full $1\,\text{minute}$ ($60\,\text{seconds}$) for ill clients or those with an altered status.

Eupnea

A respiratory rate and pattern that is within the expected normal reference range for a client's age.

Eupnea means normal, good, and unlabored breathing

Expected respiratory rate reference range for full-term newborns (birth to $28\,\text{days}$)

$$30-60\,\text{breaths/min}$$

Expected respiratory rate reference range for infants ($1\,\text{month}$ to $1\,\text{year}$)

$$25-60\,\text{breaths/min}$$

Expected respiratory rate reference range for toddlers ($1-3\,\text{years}$)

$$25-30\,\text{breaths/min}$$

Expected respiratory rate reference range for preschoolers ($3-6\,\text{years}$) and school-age children ($6-12\,\text{years}$)

$$20-25\,\text{breaths/min}$$

Expected respiratory rate reference range for adolescents ($12-20\,\text{years}$)

$$16-20\,\text{breaths/min}$$

Expected respiratory rate reference range for adults ($20\,\text{years}$ and older)

$$12-20\,\text{breaths/min}$$

Tachypnea

A respiratory rate that is higher than the expected reference range, often presenting with shallow breaths.

Physical manifestations associated with tachypnea

Dizziness and tingling sensations in the hands.

Common causes of tachypnea

Increased physical activity, pain, anxiety, respiratory infections (e.g., pneumonia), and chronic lung disease exacerbations (e.g., asthma).

Nursing interventions for pain-induced tachypnea

Administration of an analgesic, changing the client's position, and applying ice or heat.

Nursing interventions for asthma-induced tachypnea

Administration of bronchodilators and maintaining the client in an upright position.

Bradypnea

A respiratory rate that is lower than the expected reference range.

Clinical manifestations of bradypnea

Dizziness, fatigue, weakness, confusion, and impaired coordination.

Potential underlying causes of bradypnea

Increased intracranial pressure, hypothyroidism, shock, alcohol toxicity, opioid or sedative use, and morbid obesity.

Nursing interventions for opioid-induced bradypnea

Administration of naloxone, an opioid antagonist.

Nursing interventions for bradypnea secondary to increased intracranial pressure

Slightly elevating the head of the bed and administering medications to reduce brain swelling.

Apnea

The complete cessation of respirations, which can lead to respiratory arrest if persistent.

Common causes of apnea

Opioid toxicity, trauma, and neurologic dysfunction.

Cheyne-Stokes respirations

An irregular breathing pattern consisting of a cyclic progression from shallow to deep breaths, hyperventilation, and period(s) of apnea.

Causes of Cheyne-Stokes respirations

Increased intracranial pressure, brain tumors, stroke, and heart failure.

Kussmaul respirations

A regular respiratory rhythm characterized by abnormally deep and rapid breaths.

[Breathing that is very rapid but has regular rhythm, and abnormally deep]

Underlying causes of Kussmaul respirations

Severe metabolic acidosis, most commonly diabetic ketoacidosis (DKA), or severe kidney disease.

Retractions

Inward pulling of tissue in the neck, substernal, subcostal, or intercostal areas during inspiration due to the exertion of accessory muscles.

Oxygen saturation ($\text{SpO}_2$)

An indication of the percentage of oxygen being transported to body tissues.

Expected oxygen saturation reference range

$95\%-100\%$

(variations in pulse oximetry accuracy can occur for clients with highly pigmented skin tones.)

Pulse oximeter

A noninvasive device used to measure a client's oxygen saturation level.

Capillary refill requirement for reliable pulse oximetry

A refill time of less than $2\,\text{seconds}$, indicating adequate perfusion.

Preferred pulse oximetry measurement sites by age group

The finger for adults and children; the foot or wrist (using an adhesive probe) for newborns and young infants.

Indication for using the earlobe for pulse oximetry

Clients of any age who have decreased peripheral perfusion.

Pre-procedural finger preparation for pulse oximetry

Ensuring the finger is dry and free from dark-colored nail polish or artificial nails.

Method for confirming pulse oximeter accuracy

Palpating the client's radial pulse to verify it matches the pulse rate displayed on the oximeter.

Required duration to leave pulse oximeter probe in place for reading

$15-30\,\text{seconds}$ until a consistent pulse rate and saturation value are displayed.

Dyspnea

Shortness of breath or difficulty breathing reported by a client.

Hypoxia

A state in which insufficient oxygen is supplied to the body's tissues, potentially causing decreased mental alertness and confusion.

Hypoxemia

A decreased level of oxygen in the blood.

Initial nursing interventions for decreased oxygen saturation

Placing the client in an upright position, instructing deep breathing and coughing, and administering supplemental oxygen or prescribed bronchodilators.