Measuring the four vital signs temperature (T), pulse (HR), blood pressure (BP), and breathing (RR) is an essential part of the physical examination and provides information for patient assessment, monitoring, decision-making, and medical recordkeeping.
As a Respiratory Care Practitioner it is important that we are able to identify abnormal breathing patterns and can understand the nature of their cause, the effect these patterns have on the patient, and possible treatments to return the breathing pattern back to normal.
Evaluation of an adults respiratory pattern requires the following two steps:
- First, the frequency must be carefully counted and the depth of respirations should be noted as well. The respiratory rate can be counted over the course of thirty (30) seconds being careful not to let the patient alter their respiratory rate or pattern should they become aware that they are being assessed. The number obtained would then be multiplied by two to establish breaths/min. Adult patients normally breathe between 10-20 breaths/minute at rest.
- Next, the RCP should evaluate the inspiratory and expiratory lengths in each cycle of breathing. It is expected that patients have an expiratory portion that is typically twice as long as the inspiratory portion of each breath cycle.
Abnormal Respiratory Patterns
(Tachy: Greek root word meaning fast) describes respirations that have a rate or frequency above the normal limits. An adult patient is considered tachypneic if their respiratory rate is above 20 breaths/min. Tachypnea occurs for many reasons. Exercise, pain, or anxiety can all cause the respiratory rate to increase. Other causes include pathologies that cause fever, hypoxemia, metabolic acidosis and fever or intentional or unintentional high respiratory rates set on non-invasive or invasive mechanical ventilators.
(Brady: Greek root word meaning slow) is a term used to define a breathing frequency that is less than the normal limits. In an adult patient this term would identify someone who has a respiratory rate less than 10 breaths/min. Most adults have a breathing rate between 10 to 20 breaths/min to maintain the minute ventilation needed for proper acid-base balance. The human body can adjust more readily to tachypnea since ventilatory needs are most often maintained. However, in bradypnea the ventilatory needs are generally not being met and patients presenting with this condition would most likely need immediate medical attention to increase their ventilation. Causes of bradypnea include drug overdose, sedatives, decreased body temperature, head injury, and neurologic deficits or trauma.
Hyperpnea is the medical term used to describe a breathing pattern with a depth of inspiration that is very large. This term indicates that the adult’s normal tidal volume (the volume of air that the patient breathes in and out with each breath) is much larger than the predicted normal. This can be caused from inspiring a lower than normal level of oxygen or a higher than normal level of inhaled carbon dioxide, exercise, emotional stress, or diabetic ketoacidosis.
Hypopnea is a term describing lower depth of breathing. In these cases the shallow respirations are less than the predicted normal tidal volume. This can be caused from neurologic trauma or pathologies, medications such as sedatives, opioids or analgesics, neuromuscular disorders, sleep apnea, and airway obstruction.
Kussmauls breathing pattern is a combination of hyperpnea and tachypnea. This pattern of breathing found in some patients with late-stage diabetic ketoacidosis. Due to the lack of insulin these patients have a high level of blood sugar which causes a metabolic ketoacidosis. Metabolic ketoacidosis can also be caused from kidney failure. In both cases, the carbon dioxide levels in the arterial blood rise. In response, and in an effort to compensate for this metabolic disturbance, the patient will begin breathing faster (tachypnea). However, as the respiratory muscles begin to fatigue and the limits of respiratory compensation are reached, the ongoing acidosis will cause the patient to begin a respiratory pattern of hyperpnea. From this critical point, if the acidosis continues, the patients respiratory pattern will transcend into a gasping pattern of tachypnea and hyperpnea. For these patients, respiratory muscle fatigue and respiratory failure can occur quickly and mechanical ventilation should be considered until the underlying condition(s) can be managed.
Cheyne-Stokes is a unique pattern of respiration that can be caused by ketoacidosis or kidney failure, as well as brain injuries that occur above the brain stem. However, in this pattern there are three phases to the respirations. The pattern begins with shallow, fast respirations that crescendo to deeper, fast respirations (Phase 1). The breathing pattern then gradually decrescendos in depth (Phase 2) and an eventual period of apnea occurs lasting from 15 to 60 seconds (Phase 3) until the pattern is repeated again from phase 1. The pattern is repeated in cycles.
Biot’s is a pattern of breathing that does not have a cyclical or organized nature. It is characterized by irregular patterns of rapid, shallow respirations and periods of apnea. This pattern can be caused from brain injury and increased intracranial pressures.
8. Apneustic Breathing
Apneustic breathing is the term used to describe a gasping inspiration with a pause prior to a release for exhalation. This pattern of breathing is associated with brain injuries, especially injury to the pons or medulla.
Des Jardins, T. and Burton, G.G. Clinical Manifestiations and Assessment of Respiratory Disease. 7th Ed. Pp. 15-17.
Gallow de Moraes, A. and Surani, S. Effects of Diabetic Ketoacidosis in the Respiratory System. World Journal of Diabetes. 2019 Jan 15; 10(1): 16–22.