Maastricht Classification
NHBDs are grouped by the Maastricht classification:
| I | Brought in dead | uncontrolled | |
| II | Unsuccessful resuscitation | ||
| III | Awaiting cardiac arrest | controlled | |
| IV | Cardiac arrest after brain-stem death | ||
| V | Cardiac arrest in a hospital inpatient | uncontrolled (added in 2000) | |
Categories I, II and V are termed uncontrolled and categories III and IV are controlled. Only tissues such as heart valves and corneas can be taken from category I donors. Category II donors are patients who have had a witnessed cardiac arrest outside hospital, have cardiopulmonary resuscitation by CPR-trained providers commenced within 10 minutes but who cannot be successfully resuscitated. Category III donors are patients on intensive care units with non-survivable injuries who have treatment withdrawn; where such patients wished in life to be organ donors, the transplant team can attend at the time of treatment withdrawal and retrieve organs after cardiac arrest has occurred.
Read more about this topic: Non-heart-beating Donation