The ARDS medical abbreviation stands for acute respiratory distress syndrome, a serious lung injury in which inflammation makes the tiny air sacs leak fluid, so oxygen cannot pass into the blood well. It develops quickly, usually within a week of an illness or injury such as sepsis, pneumonia or major trauma, and most people with it are cared for in an intensive care unit.
Families often hear the term at the bedside before they see it written. In notes it sits beside ventilator settings, oxygen ratios and chest imaging. The word syndrome is chosen on purpose: ARDS is a pattern of lung damage with many possible triggers rather than one single disease. This page explains how ARDS is defined and graded, what the ICU numbers around it mean, and which neighboring terms get mixed up with it.
At a glance
Stands for
Acute respiratory distress syndromeOlder name
Adult respiratory distress syndrome, no longer usedCommon triggers
Sepsis, pneumonia, aspiration, trauma, pancreatitisSeverity measure
P/F ratio, arterial oxygen divided by inspired oxygen fractionWhere you see it
ICU progress notes, ventilator flowsheets, chest imaging reportsSpecialty
Critical care, pulmonologyDo not confuse with
RDS, a newborn lung condition
What the ARDS medical abbreviation means
In ARDS, something injures the lungs directly, such as pneumonia or inhaled stomach contents, or indirectly, such as a severe infection elsewhere in the body. The injury sets off widespread inflammation. Fluid and protein leak from small blood vessels into the air sacs, the sacs collapse or fill, and the lungs become stiff and heavy.
The result is very low oxygen in the blood despite extra oxygen being given. Breathing becomes fast and hard. Imaging of the chest shows cloudy patches in both lungs. Doctors also check that the fluid is not simply caused by heart failure, because that would point to a different problem with different treatment.
How ARDS is graded by severity
Teams grade ARDS using the P/F ratio, which compares the oxygen level in arterial blood with the share of oxygen the person is breathing. Lower numbers mean worse oxygen transfer. A widely used definition grades it this way, measured while the ventilator provides at least a small amount of steady pressure.
| Grade | P/F ratio | Plain reading |
|---|---|---|
| Mild | Above 200, up to 300 | Oxygen transfer clearly reduced |
| Moderate | Above 100, up to 200 | Marked reduction |
| Severe | 100 or lower | Very poor oxygen transfer |
Newer definitions also allow oxygen saturation readings in place of a blood gas, especially where blood gas testing is not available. Hospitals may follow slightly different criteria.
Decoding an ARDS ventilator note
ICU notes are full of numbers. Each figure in the example line near the page title is unpacked below.
| Entry | Meaning |
|---|---|
| Severe ARDS | Acute respiratory distress syndrome in the severe grade |
| from sepsis | Triggered by a body-wide response to infection |
| P/F 85 | Oxygen ratio of 85, in the severe range |
| PEEP 14 | Positive end expiratory pressure, a constant push of air that stops the small sacs collapsing |
| proned 16 hrs | Placed face down for 16 hours to help oxygen levels |
At morning rounds: "ARDS improving, FiO2 down to 45 percent, plan spontaneous breathing trial tomorrow." The team is saying the oxygen need has fallen and they hope to test whether the patient can breathe with less ventilator help.
Care approaches you may read about
There is no single medicine that reverses ARDS, so care focuses on supporting the lungs while they heal and treating the trigger. Most patients need a breathing tube, listed as an ETT, and a ventilator. Teams use small breath sizes, often called low tidal volume ventilation, to avoid stretching the injured lungs. Lying face down, known as prone positioning, can improve oxygen in moderate to severe cases.
Other common notes involve sedation, careful fluid balance, nutrition and preventing clots and pressure injuries. In the most severe cases, some centers use a heart-lung bypass machine to oxygenate the blood outside the body. Recovery can take weeks, and many survivors need rehabilitation for weakness afterward.
ARDS compared with similar breathing terms
Several abbreviations look or sound like ARDS but mean different things.
- RDS (respiratory distress syndrome) usually means a newborn lung problem from immature lungs, mainly in premature babies.
- AHRF (acute hypoxemic respiratory failure) is the umbrella label for low blood oxygen whatever the reason; ARDS is just one reason.
- PNA (pneumonia) is a common trigger of ARDS but is not the same condition.
- Cardiogenic pulmonary edema also fills the lungs with fluid, but from heart failure rather than leaky inflamed vessels.
- SIRS describes a body-wide inflammatory response that may come before or alongside ARDS.
For students reading ARDS charts
ARDS is a standard, accepted abbreviation, and many staff say it as one word. When charting, pair it with the trigger, the grade and the current oxygen and ventilator settings, since those numbers show the trend from day to day. An ABG result is usually needed to calculate the P/F ratio. Browse further illness shorthand in the diagnosis abbreviation guide.
These explanations describe intensive care language in general. The ICU physician and nurses are the people to ask about a loved one's condition, progress and plan.
Frequently asked questions
What does ARDS stand for?
ARDS stands for acute respiratory distress syndrome. It is a serious lung injury where inflamed air sacs fill with fluid and oxygen levels fall.
What causes ARDS?
Common triggers include sepsis, pneumonia, breathing in stomach contents, major injuries and pancreatitis. It can also follow some blood transfusions or smoke inhalation.
Is ARDS the same as pneumonia?
No. Pneumonia is an infection and can be one cause of ARDS. ARDS is the pattern of widespread lung injury that can follow pneumonia or many other problems.
What does P/F ratio mean in ARDS?
It is the arterial oxygen level divided by the fraction of oxygen being breathed. Lower values mean the lungs are moving oxygen poorly, and the number is used to grade ARDS.
How do you pronounce ARDS?
Plenty of ICU staff pronounce it as one word, rhyming with cards. Others spell out A-R-D-S, and both are fine.