The respiration rate is one of the most noticeable physiological changes that occurs as a person nears the end of life. These alterations in breathing patterns are a natural, expected part of the body’s final transition, reflecting a systemic slowing down of function. While a typical adult breathes between 12 and 20 times per minute, the rate and rhythm become highly irregular in the last hours and days of life. Understanding these changes is helpful for families and caregivers, as the observed patterns often cause distress to observers, even though they may not cause discomfort to the dying person.
Physiological Causes of Respiratory Changes
The primary reason for altered breathing at the end of life is the progressive failure of the body’s major organ systems. As circulation slows and metabolic demands decrease, the body’s ability to regulate the balance of gases in the blood is compromised. This reduced efficiency leads to a buildup of carbon dioxide (CO2) and an increase in acid levels, a condition known as metabolic acidosis.
The brainstem, which controls involuntary functions like breathing, becomes less responsive to the chaotic blood gas levels. Normally, respiratory centers in the brain adjust breathing to maintain precise CO2 and oxygen levels. However, as the body weakens and the heart struggles to circulate blood, the brainstem receives delayed or inaccurate signals about the gas composition of the blood.
This poor communication results in a loss of the precise, rhythmic control over respiration. The signal to breathe becomes erratic, leading to unpredictable pauses and variations in the depth and rate of each breath. Essentially, the regulatory system that keeps breathing steady is suppressed, causing the chaotic, irregular breathing patterns characteristic of the dying process.
Distinct Breathing Patterns in the Dying Process
One of the most frequently observed patterns is Cheyne-Stokes respiration, a cyclical pattern of breathing that is often unsettling to witness. This rhythm involves a period where breaths start shallowly, then gradually increase in depth and rate, culminating in deep, rapid breaths. Following this hyperventilation phase, the breaths slow down and become shallower again, eventually leading to a period of apnea, which can last up to two minutes.
This waxing and waning pattern is related to the circulatory delay between the lungs and the brain’s respiratory center. When the individual breathes deeply, CO2 is flushed out, causing the brain to temporarily stop breathing. This allows CO2 to build up again and restart the cycle. Cheyne-Stokes breathing is a sign of neurological or circulatory changes, such as heart failure, and often appears in the days or hours leading up to death.
Another pattern is agonal breathing, which appears as slow, shallow, and irregular breaths, sometimes described as gasping or guppy-like mouth movements. Agonal breaths are involuntary, reflexive actions of the brainstem that are not effective for oxygen exchange. These movements are very erratic, with long pauses followed by short bursts of shallow breathing, and are typically a late-stage event.
A change in sound, often coinciding with a very slow or irregular rate, is terminal secretions, commonly known as the “death rattle”. This gurgling or rattling sound is caused by the inability to cough or swallow saliva and mucus accumulated in the upper airways. While the sound can be distressing for family members, it does not indicate that the person is choking or in pain, as they are usually unconscious or semi-conscious at this stage.
Managing Discomfort Associated with Breathing Changes
Care for altered breathing patterns focuses entirely on ensuring the patient’s comfort rather than attempting to normalize the respiratory rate. When a person appears short of breath, or experiencing dyspnea, medical staff may use low-dose opioids, such as morphine, which ease the perception of “air hunger.” These medications are effective even if the person’s measured oxygen levels are within a normal range.
Non-drug interventions are also a central part of comfort care. Repositioning the person, such as turning them onto their side or elevating the head, helps manage secretions and improve breathing comfort. Increasing air movement by directing a small fan toward the patient’s face provides a sensation of relief from breathlessness.
For terminal secretions, the primary intervention involves repositioning the patient to allow gravity to drain the fluid. Medications called anticholinergics may be used to reduce the production of new secretions, but suctioning is often avoided as it can cause discomfort and irritation. Oxygen therapy is of limited use in the final hours, as the underlying problem is not oxygen deficiency but a failure of the body’s entire regulatory system.