Acute respiratory distress syndrome

Acute respiratory distress syndrome
Other namesRespiratory distress syndrome (RDS), adult respiratory distress syndrome, shock lung
Chest x-ray.
SpecialtyCritical care medicine
SymptomsShortness of breath, rapid breathing, bluish skin coloration Chest pain or pressure, Loss of speech of movement[1]
Usual onsetWithin a week[1]
Diagnostic methodAdults: PaO2/FiO2 ratio of less than 300 mm Hg[1]
Children: oxygenation index > 4[2]
Differential diagnosisHeart failure[1]
TreatmentMechanical ventilation, ECMO[1]
Prognosis35 to 90 % risk of death[1]
Frequency3 million per year[1]

Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs.[1] Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin coloration (cyanosis).[1] For those who survive, a decreased quality of life is common.[3]

Causes may include sepsis, pancreatitis, trauma, pneumonia, and aspiration.[1] The underlying mechanism involves diffuse injury to cells which form the barrier of the microscopic air sacs of the lungs, surfactant dysfunction, activation of the immune system, and dysfunction of the body's regulation of blood clotting.[4] In effect, ARDS impairs the lungs' ability to exchange oxygen and carbon dioxide.[1] Adult diagnosis is based on a PaO2/FiO2 ratio (ratio of partial pressure arterial oxygen and fraction of inspired oxygen) of less than 300 mm Hg despite a positive end-expiratory pressure (PEEP) of more than 5 cm H2O.[1] Cardiogenic pulmonary edema, as the cause, must be excluded.[3]

The primary treatment involves mechanical ventilation together with treatments directed at the underlying cause.[1] Ventilation strategies include using low volumes and low pressures.[1] If oxygenation remains insufficient, lung recruitment maneuvers and neuromuscular blockers may be used.[1] If these are insufficient, extracorporeal membrane oxygenation (ECMO) may be an option.[1] The syndrome is associated with a death rate between 35 and 50%.[1]

Globally, ARDS affects more than 3 million people a year.[1] The condition was first described in 1967.[1] Although the terminology of "adult respiratory distress syndrome" has at times been used to differentiate ARDS from "infant respiratory distress syndrome" in newborns, the international consensus is that "acute respiratory distress syndrome" is the best term because ARDS can affect people of all ages.[5] There are separate diagnostic criteria for children and those in areas of the world with fewer resources.[3]

  1. ^ a b c d e f g h i j k l m n o p q r s Fan, E; Brodie, D; Slutsky, AS (20 February 2018). "Acute Respiratory Distress Syndrome: Advances in Diagnosis and Treatment". JAMA. 319 (7): 698–710. doi:10.1001/jama.2017.21907. PMID 29466596. S2CID 3451752.
  2. ^ Cheifetz, Ira M (25 May 2017). "Pediatric ARDS". Respiratory Care. 62 (6): 718–731. doi:10.4187/respcare.05591. PMID 28546374.
  3. ^ a b c Matthay, MA; Zemans, RL; Zimmerman, GA; Arabi, YM; Beitler, JR; Mercat, A; Herridge, M; Randolph, AG; Calfee, CS (14 March 2019). "Acute respiratory distress syndrome". Nature Reviews. Disease Primers. 5 (1): 18. doi:10.1038/s41572-019-0069-0. PMC 6709677. PMID 30872586.
  4. ^ Fanelli, Vito; Ranieri, V. Marco (2015-03-01). "Mechanisms and clinical consequences of acute lung injury". Annals of the American Thoracic Society. 12 Suppl 1: S3–8. doi:10.1513/AnnalsATS.201407-340MG. ISSN 2325-6621. PMID 25830831.
  5. ^ Cite error: The named reference definition-ARDS was invoked but never defined (see the help page).