SNHD Paramedic Protocols Practice Test

Death pronouncement in the field relies on postmortem changes that prove circulation and metabolism have ceased. The two conclusive signs are dependent lividity and rigor mortis. Dependent lividity is the pooling of blood in the lowest parts of the body after circulation stops, producing a characteristic purplish discoloration. Rigor mortis is the progressive stiffening of muscles due to chemical changes in the muscles after death, beginning a few hours after death and reaching full rigidity within hours. When both signs are present, they together confirm that death has occurred, since they reflect ongoing cessation of circulation and metabolic processes beyond reversible states. One sign alone is not definitive, and timing can vary with temperature and other factors, but the combination of dependent lividity and rigor mortis is the best indicator in the field.