Peri mortem describes a phase in the biological process of death. It represents the transitional period between life and definitive death. Understanding this phase helps in grasping the changes that occur as an organism ceases to function.
Defining Peri Mortem
Peri mortem refers to the time immediately surrounding the cessation of life. This transitional phase spans minutes to hours both before and after the heart stops beating and breathing ceases. It encompasses the changes as the body moves from a living state to irreversible biological cessation.
Clinical death, defined by the cessation of breathing and heartbeat, often marks the beginning of the peri mortem period. Biological death, which signifies irreversible cellular damage, may occur later as oxygen deprivation leads to widespread tissue demise. The peri mortem phase includes the window during which resuscitation efforts might be attempted, before cellular functions are permanently lost.
Physiological Changes During Peri Mortem
As a person enters the peri mortem phase, the body undergoes a systemic shutdown. The cardiovascular system experiences a decline in heart function, leading to a significant drop in blood pressure and impaired circulation. This reduced blood flow can manifest as mottling, a purplish discoloration of the skin, particularly in the extremities, as blood pools due to slowed circulation.
The respiratory system also changes, with breathing becoming shallow and irregular. Patterns such as Cheyne-Stokes respiration, characterized by periods of deep, rapid breathing alternating with periods of apnea, are common. Eventually, breathing ceases entirely as the respiratory drive fails.
In the nervous system, decreased brain activity becomes evident, leading to a loss of reflexes and responsiveness. As oxygen supply diminishes, brain cells begin to die within minutes, potentially leading to brain death, the irreversible loss of all brain function, including the brainstem. At the cellular level, oxygen deprivation, known as hypoxia, leads to the accumulation of metabolic waste products and depletion of cellular energy, causing the breakdown of cellular integrity.
Clinical Indicators of Peri Mortem
Observable signs indicate a person is in the peri mortem phase. Vital signs show alterations, including a drop in blood pressure, a weak or absent pulse, and increasingly shallow or absent breathing. These changes are direct manifestations of failing cardiovascular and respiratory systems.
Neurological signs become evident, with unresponsiveness to stimuli, fixed and dilated pupils, and the absence of reflexes. The eyes may appear glassy or milky, sometimes remaining partially open and unfocused. Skin changes are common, with pallor or cyanosis (a bluish discoloration) becoming noticeable, and the skin often feels cool to the touch, especially in the hands and feet.
Other indicators include a loss of bladder or bowel control due to muscle relaxation. Gurgling sounds, often referred to as a “death rattle,” can occur as fluid accumulates in the throat and airways, which the individual can no longer clear effectively. These signs show the body’s diminishing capacity to sustain life.
Medical Management and Outcomes
Medical approaches during the peri mortem period vary based on the patient’s condition and prognosis. Care differentiates between resuscitative efforts, aimed at reversing clinical death, and palliative or comfort care, which focuses on easing suffering when death is imminent. Cardiopulmonary resuscitation (CPR) and ventilation are interventions used to reverse clinical death, especially if the underlying cause is treatable and cardiac arrest is sudden.
In palliative care, where patients often have advanced illnesses, the success rate of CPR is considerably lower, leading to careful consideration of its application. Advance care planning is used to determine patient preferences regarding resuscitation, ensuring their wishes are respected. If the underlying condition is profound or treatment is delayed, the peri mortem phase often progresses to irreversible biological death, despite interventions.
Differentiating Peri Mortem from Post Mortem
It is important to distinguish peri mortem from post mortem, as they describe different stages relative to death. Peri mortem refers to the transitional period at or around the moment of death, encompassing the active process of dying and the immediate aftermath before irreversible changes fully set in. This phase involves the body’s active shutdown and the window where interventions, though often limited, might still have an impact.
Post mortem refers to the period after death has occurred, once life has ceased. This phase focuses on the changes that happen to the body once biological functions have irreversibly stopped, such as rigor mortis (stiffening of muscles), livor mortis (discoloration due to blood pooling), and the onset of decomposition. The distinction lies in peri mortem being about the dynamic process of dying, while post mortem describes the static state and subsequent changes to the body after death.