Principles of critical care nursing
1. Pathophysiology of critical illness
Primary role of CVS and respiratory system is to provide oxygen to the microcirculatory bed cells.
Critical illness is a state of threatened generalized cellular hypoxia as a result of cardio respiratory dysfunction
Cardio respiratory dysfunction can be either primary or secondary
Primary: occurs as a result of diseases in cardiac or respiratory system
Secondary: Occurs as a result of sepsis, trauma etc.
2.Reversible stage of critical illness
Oxygen transport to the tissue is increased.
As a result, tachypnea, tachycardia, increased cardiac output, low BP warm and flushed peripheries. This is an early reversible stage-warm shock.
The next cold stage shock is characterized by cold and clammy peripheries, poor capillary filling and cyanosis.
3. Irreversible stage of critical illness
When oxygen demand exceeds oxygen supply anaerobic metabolism takes place
leads to metabolic acidosis.
If this is unchecked, will result in irreversible damage which precedes cellular death.
The microcirculation fails and become hypoxic, cellular damage occurs.