Vital signs are vital: Respiration

The following is one in a series of columns by guest authors illustrating the importance of vital signs to the practice of hospital medicine.

You are paged by a nurse regarding a family's growing concern over a patient's breathing pattern. You recall the nurse saying the patient's respiratory rate has been normal all morning, but while sleeping it varies between periods of hyperpnea and near-apnea. The patient is in no other distress. When you speak with the family, they express their concern about this being the patient's third hospitalization in the last year for decompensated heart failure. Passively observing the patient sleeping, you notice periods of slow to apneic breathing followed by an increase in the respiratory rate with breaths occurring every other second. The volume of breath also appears to increase in these recovery periods. You correctly identify this as a Cheyne-Stokes respiratory pattern and explain to the family its correlation with heart failure.

Although Hippocrates may have been one of the earliest physicians to document this breathing pattern, it wasn't until the 19th century that a Scottish physician, John Cheyne, described it in more intricate detail and tied it to “apoplexy of the heart.” Dr. Cheyne grew up attending to his father's patients before studying medicine at the University of Edinburgh. After obtaining his medical degree in 1795 at the ripe age of 18, he joined the British army and worked as a surgeon for 4 years before moving to Dublin to work as a physician at Meath Hospital.

It was during this time he drafted the famous description “a case of apoplexy in which the fleshy part of the heart was converted into fat.” In his original description of the respiratory pattern bearing his name, he described patient A.B., who at “sixty years of age, of a sanguine temperament, circular chest, and full habit of body, for years had lived a very sedentary life, while he indulged habitually in the luxuries of the table.” He reports the patient complained for several years of palpitations and edema of the feet and body. At the end of a course of what was likely worsening heart failure and stroke, Cheyne writes about a peculiar pattern of breathing lasting 8 or 9 days. He wrote, “His breathing was irregular. It would entirely cease for a quarter of a minute then it would be perceptible..it became heaving and quick, and then it would gradually cease again.” He noted during this time period a respiratory rate of 30 breaths per minute.

We now understand this pattern of altered breathing is driven by alterations in serum partial pressures of oxygen and carbon dioxide. The most likely underlying pathology is chronic heart failure or damage to the central respiratory nuclei. It can also be found in newborns with immature respiratory center development or during sleep in individuals visiting high altitudes. Two decades after his service in the army, Dr. Cheyne was appointed Physician General to the army of Ireland, the highest medical rank in the country. He eventually left Dublin and settled down in Sherington, England, where he looked after the health of the villagers until his death in 1836.

In 1854, William Stokes went on to ascribe the respiration to “a lesion in the heart” in his 1854 text “The Diseases of the Heart and Aorta.” Dr. Stokes was an Irish physician, one of the first to pioneer the use of the stethoscope. He emphasized the importance of good physical exam skills in leading physicians to the correct diagnoses. Following his publications on the pathophysiology of heart and lung disease, he was elected as a fellow of the Royal Society in 1861.

Monitoring respiratory rate and use of accessory muscles in adults and children helps predict pending respiratory failure. Determining the characteristics of each respiration with small or large tidal volumes, wheezing, or stridorous sounds can help guide one down the correct diagnostic pathway. More in-depth tests of pulmonary function are also important predictors of disease outcome.

In the era of electronic medical records, where vital signs and physical exam findings are often “pulled in” without much thought, Dr. Stokes would tell us that vital signs are still vital. It remains of utmost importance to continue to train young physicians in the art of patient observation and examination, including respiration.