Kussmaul breathing is a deep and labored breathing pattern often associated with severe metabolic acidosis, particularly diabetic ketoacidosis (DKA) but also

kidney failure Kidney failure, also known as renal failure or end-stage renal disease (ESRD), is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney fa ...

. It is a form of

hyperventilation Hyperventilation is irregular breathing that occurs when the rate or tidal volume of breathing eliminates more carbon dioxide than the body can produce. This leads to hypocapnia, a reduced concentration of carbon dioxide dissolved in the blo ...

, which is any breathing pattern that reduces carbon dioxide in the blood due to increased rate or depth of respiration. In metabolic acidosis, breathing is first rapid and shallow but as acidosis worsens, breathing gradually becomes deep, labored and gasping. It is this latter type of breathing pattern that is referred to as Kussmaul breathing.

Terminology

Adolf Kussmaul referred to breathing when metabolic acidosis was sufficiently severe for the respiratory rate to be normal or reduced. This definition is also followed by several other sources, including for instance Merriam-Webster, which defines Kussmaul breathing as "abnormally slow deep respiration characteristic of air hunger and occurring especially in acidotic states". Other sources, however, use the term Kussmaul respiration also when acidosis is less severe, in which case breathing is rapid. Kussmaul breathing occurs only in advanced stages of acidosis, and is not commonly seen. Rapid, shallow breathing may be observed in less severe cases but Kussmaul breathing is a characteristic deep, gasping - even desperate - manner of respiratory distress.

History

Kussmaul breathing is named for Adolf Kussmaul, the 19th century German

physician A physician, medical practitioner (British English), medical doctor, or simply doctor is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through the Medical education, study, Med ...

who first noted it among patients with advanced

diabetes mellitus Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained hyperglycemia, high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or th ...

Mechanism

Kussmaul breathing is respiratory compensation for a metabolic acidosis, most commonly occurring in diabetics in diabetic ketoacidosis. Blood gases of a patient with Kussmaul breathing will show a low partial pressure of CO₂ in conjunction with low

bicarbonate In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula . Bicarbonate serves a crucial bioche ...

because of a forced increased respiration (blowing off the

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

Base excess In physiology, base excess and base deficit refer to an excess or deficit, respectively, in the amount of base present in the blood. The value is usually reported as a concentration in units of mEq/L (mmol/L), with positive numbers indicating an ...

is severely negative. The patient feels an urge to breathe deeply, an "air hunger", and it appears almost involuntary. A metabolic acidosis soon produces hyperventilation, but at first it will tend to be rapid and relatively shallow. Kussmaul breathing develops as the acidosis grows more severe. Indeed, Kussmaul originally identified this type of breathing as a sign of coma and imminent death in diabetic patients. Duration of fasting, presence or absence of liver enlargement and Kussmaul breathing provide clues to the

differential diagnosis In healthcare, a differential diagnosis (DDx) is a method of analysis that distinguishes a particular disease or condition from others that present with similar clinical features. Differential diagnostic procedures are used by clinicians to di ...

of high blood sugar in the inborn errors of metabolism.

References

{{Eponymous medical signs for respiratory system Endocrinology Breathing abnormalities