Question: What’s the clinical difference between comatose and persistent vegetative state (PVS)? Can I use the terms interchangeably for a resident who is not conscious? Maine Subscriber Answer: The RAI Manual defines these phrases differently, even though both appear together on MDS item B0100 (Comatose): Comatose (coma): A pathological state in which neither arousal (wakefulness, alertness) nor awareness exists. The person is unresponsive and cannot be aroused; he/she does not open his/her eyes, does not speak and does not move his/ her extremities on command or in response to noxious stimuli (e.g., pain). Persistent vegetative state: Sometimes residents who were comatose after an anoxic-ischemic injury (i.e., not enough oxygen to the brain) from a cardiac arrest, head trauma, or massive stroke, regain wakefulness but do not evidence any purposeful behavior or cognition. Their eyes are open, and they may grunt, yawn, pick with their fingers, and have random body movements. Neurological exam shows extensive damage to both cerebral hemispheres.