The lowest oxygen level before death is any oxygen level below 80%.
When it comes to blood oxygen levels, there's no single exact blood oxygen level that causes death, because the body can shut down at varying percentages of oxygen levels depending on a persons overall health.
Although, normal oxygen levels are 95% to 100%, and oxygen levels below 80% to 85% cause critical organ distress, and oxygen levels that drop into the 70s or lower percentage often signal a persons final hours or days of life, although pulse oximeters can also become inaccurate at very low oxygen level ranges.
A 95% to 1005 oxygen level reading is normal, healthy blood oxygen range.
A 90% to 94% oxygen level reading is mild low oxygen or (hypoxia), in which the body tissues still function, but also need monitoring.
A 80% to 89% oxygen level is a dangerous oxygen level, which causes confusion, extreme shortness of breath, and even potential brain injury.
And a oxygen level that is below 80%, is critically life threatening, as severe risk of organ failure as well as cardiac arrest can occur.
And skin discoloration and major cognitive loss often happen when the blood oxygen levels are in the 60s and 70s.
In natural end of life or hospice transitions, oxygen saturation also frequently drifts downward as the persons breathing slows, which is a normal part of the dying process, instead of an acute emergency.
Also most standard finger pulse oximeters fail to read accurately or lose signal entirely when the oxygen saturation falls below 80%, or when a persons circulation drops near death.
In the final minutes before death occurs, the body undergoes a profound slowing down of vital functions, which included prolonged pauses in breathing (apnea), a dramatic drop in blood pressure and profound unresponsiveness.
The physical changes that occur in the final minutes before a person dies includes.
Shifts in breathing, in which respiration becomes very shallow, irregular or even slow, which features long gaps of 10 to 30 seconds or more between breaths.
Agonal gasping, which involves reflexive, sporadic gasps that may occur just before the breathing stops entirely.
Circulation drop, where the dying persons blood pressure falls sharply, and the hands and feet or arms grow cold as the blood flow concentrates near the core.
And the skin can turn pale, bluish or even mottled due to reduced circulation.
And then the dying person becomes deeply unconscious and unresponsive to sound or touch.
And then facial muscles completely relax, the jaw might drop and the eyes can even remain partly open.
And finally hearing fades, and brain activity disconnects from the outside world.
The last sense to go before death is hearing.
When a person is dying, hearing is widely considered to be the last sense to leave the body.
Hospice care experts and even scientific studies also note that when someone becomes unconscious or unresponsive, the persons brain can still process sound tones.
When a person is dying the senses shut down in order of hunger and thirst fading first, followed by a drop in speech as well as vision and touch.
The auditory parts of the human brain can stay active in and during the final hours of life before death, which was found in research using brain wave tests.
When a person is dying, you can still talk, read or sing to the dying person, as the dying person may still hear you even if they can't reply to you.
You should also keep the room calm and even use familiar and comforting words or music when the person is dying.
The transition (or pre-active) stage of dying, which precedes the final "actively dying" phase typically lasts from a couple of weeks to a few months.
During this time, the body begins its natural shutdown.
Common signs during this dying transitional phase include:
Increased sleep: The individual may sleep up to 18 hours a day.
Decreased appetite: The body's natural hunger and thirst mechanisms begin to shut down, leading to a drastically reduced intake of food and fluids.
Physical weakness: Profound fatigue often leaves the person mostly bedbound.
Cognitive changes: Periods of confusion, disorientation to time or place, and mental withdrawal.