CPR (Cardiopulmonary Resuscitation) is an emergency procedure which purpose is to bring back a crewmember 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 drop to zero, they are downed, preventing any movement or actions, and the Oxygen Low affliction is added if they didn't already suffer from it. At this point, only a fellow crewmember can save them 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 right corner. Doing so will start the process, each pump slowing the progression, or even bringing down the Low Oxygen affliction if the Character performing CPR has a high enough Medical skill. Each pump also has a set chance of reviving the target.
Before starting CPR, one should make sure that the downed Character has oxygen available, 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 reviving the target (letting them regain consciousness). 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-[medicalskill])*0.05. At level 20 and higher, no damage is inflicted.
In many situations, oxygen deprivation is not the most critical emergency; as such, if, for instance, a Character is bleeding out, applying Bandages or Plastiseal prior to performing CPR is advisable. Any active Affliction that deals more damage to the Character's vitality than Oxygen Low should be treated before attempting CPR. 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.