Pulmonology
Rene Laennec’s stethoscope
Pulmonology, also known as respiratory medicine, is the field that diagnoses and manages non-malignant lung disease. We know that diseases of the lung are among the oldest medical conditions, as a treatment for asthma is mentioned in the Ebers papyrus from ancient Egypt (1550 BC). In 300 BC, Erasistratus of Alexandria described the pneumatic theory of respiration, postulating that air travelled through the lungs to the heart and then through air-filled arteries to the peripheral tissue*. Fast forward to the Renaissance: Da Vinci dissected humans, found that air contained something that supported combustion, and that subatomospheric pressure intrapleural pressure inflates the lungs. Vesalius, the father of anatomy, performed a thoractomy on a pig, devised the world’s first tracheotomy and performed CPR on an apparently dead person.
*Not quite, but close, considering the tools of the day. William Harvey (1578-1657) tied the circulation in the correct package, recognizing that the ventricles pumped blood through the arteries and returned to the heart via the veins, thus functioning as a closed circuit. He postulated the existence of capillaries to connect arterioles to venules, which was confirmed by in 1661 by Marcello Malpighi (1628-1694).
pulmonology oxygen dissociation curve
The 17th and 18th century saw an array of advances in pulmonary medicine and its underlying science with Torricelli’s construction of the barometer (1643); Robert Boyle’s recognition of the inverse relationship between gas pressure and volume (1662, Boyle’s law)–which explains in part the mechanics of breathing; John Fothergill’s description of mouth-to-mouth resuscitation (1744); Joseph Black’s discovery of carbon dioxide (1760s); Joseph Priestley’s discovery of oxygen (1774); and Antoine Lavoisier’s* recognition that oxygen was inhaled and carbon dioxide and water vapor exhaled.
*Lavoisier was a nobleman during the French Revolution, whose fertile scientific production was cut short by a guillotine in 1794.
Discoveries of the 19th and early 20th century that led to modern pulmonology include Laennec’s invention of the stethoscope (1816, see top image) and his seminal work Diseases of the Chest and Auscultation (1838), Hutchinson’s spirometer (1846); Fick’s formula for calculating cardiac output based on oxygen consumption and oxygen content in the arteries and vein (1855); Jones’ negative pressure ventilation device (1864); Pasteur’s germ theory (1865), leading to recognition that most lung infections are bacterial in nature; Röntgen’s X-rays (1895), leading to the first widely used diagnostic tool (plain films) for diagnosing lung disease; Christian Bohr’s oxygen dissociation curve (1904, upper middle image); von Linde’s commercial production of oxygen (1907); and Jackson’s laryngoscope for inserting endotracheal tubes (1913).
fiberoptic bronchoscopy
The early 20th century saw the end of the “brilliant scientist era”, with more and more advances and discoveries being the result of brilliant teamwork. Isoproterenol/isoprenaline, a beta1 and beta2 bronchodilator was formulated as an aerosol for managing asthma (1940); various respiratory disorders began to be treated using IPPB (1945); ventimask with controllable oxygen levels became available (1960); fiberoptic bronchoscopes developed (1968, bottom image, bronchoscopy); Swan-Ganz catheter developed for measuring pulmonary artery pressure (1970); AIDS first reared its ugly head (1981).
Spirometry schematic