CPR (Cardiopulmonary Resuscitation) is an emergency procedure which purpose is to bring back a crew member that has been rendered unconscious after sustaining major injuries or having been deprived of Oxygen for too long.
Most Afflictions, such as Internal Damage or Oxygen Low, will damage a character's Vitality. When their vitality drops to zero or below they become unconscious, preventing any movement or actions (including breathing), and the Oxygen Low affliction is added if they didn't already suffer from it. Once unconscious, only a fellow crew member can save them. Characters with the Oxygen Low affliction can be treated by pressing the Health key (H by default) on the downed character to open their Health GUI, then clicking the "Perform CPR" button in the bottom left corner. Doing so will start the process, each pump slowing the progression, or even reducing the Oxygen Low affliction if the character performing CPR has a high enough Medical skill. Characters with a medical skill less than 20 have a chance to cause damage to the patient with every pump. Each pump also has a set chance of fully removing the Oxygen Low affliction, restoring the patient to consciousness as long as other afflictions do not keep their vitality at zero or below.
While CPR can be performed even if the patient does not have access to an oxygen source they will quickly fall unconscious again if no oxygen is available. So one should make sure that the downed character has oxygen available before or after CPR, either by bringing them to a room that isn't flooded and is supplied with oxygen (using the Grab key, G by default), or by equipping them with a Diving Mask or Diving Suit with enough oxygen (also done by grabbing them and dropping the Mask/Suit in the appropriate slot in their inventory).
A character's Medical skill determines how well they perform CPR.
- Stabilization chance: Skill level affects how much each pump reduces the Oxygen Low affliction. At level 20 and below, CPR will halve its progression; level 50 is the middle point, where the affliction is stabilized; beyond that, each pump will bring it down.
- Revive chance: Each pump has a chance of completely removing the Oxygen Low affliction from the patient (restoring them to consciousness as long as other afflictions do not keep their vitality at zero or below). At level 20 and below, the chance is 5%; at level 50, the chance is 25%; at level 100, the chance is 90%.
- Internal Damage: Below 20, each pump will inflict Internal Damage. The lower the skill, the higher the damage, which is calculated using the following formula:
(20 - Skill) * 0.05. At level 20 and higher, no damage is inflicted.
In many situations, oxygen deprivation is not the only serious affliction affecting a character; as such, if, for instance, a character is bleeding out, applying Bandages or Plastiseal prior to performing CPR is advisable. CPR is not required if a patient has other afflictions that can be treated to bring their vitality back above zero as once the patient regains consciousness they will resume breathing on their own and if oxygen is available the Oxygen Low affliction will quickly disappear. Oxygen Low deals 0 to 2 damage per second to vitality, depending on its strength, which is displayed as a gauge under its icon in the Health GUI.
- Cardiopulmonary Resuscitation is a real life emergency first-aid procedure. It is done on people who are in cardiac arrest.
A doctor performing CPR on a downed crewmate.
The CPR button in its inactive and active states.