- Not enough fluid in the blood vessels (hypovolemia) OR
- Fluid has moved outside the vessels, so cannot be pumped to the organs (distributive) OR
- Heart cannot pump fluid that is present (cardiogenic)
- Early stages of shock activate the sympathetic nervous system. So in early stages, the client will not always be hypotensive.
- Bradycardia is a very late sign in shock.
- Another late sign is cardiac arrhythmia (other than sinus tachycardia). Arrhythmias reflect less perfusion of the coronary arteries and myocarditis.
- As the myocardium receives less perfusion, heart pumps less.
- Because less blood perfuses the brain, level of consciousness drops.
- As blood flow to lungs decreases, less gas exchange will occur.
- When tissues receive less oxygen, they produce more lactate and metabolic acidosis sets in. Metabolic acidosis increases risk of cardiac arrhythmias.
- For a client in shock, body cells receive less oxygen and nutrients. Thus treatment aims at increasing both available oxygen and volume of blood in vessels (unless the heart has failed).
- Medications can improve tone of blood vessels (inotropes) or treat the cause of shock (corticosteroids, antibiotics).
- When treating a trauma client, you must quickly assess ABCs. After you know the client is breathing and has a pulse, vital signs can wait while you stop any bleeding and start other interventions (such as starting IVS). Don't rely only on the vital sign numbers.
- If client has head injury, the most important assessment is level of consciousness; next is pupil response to light. Changes in vitals are very late sign.
- With trauma clients, assume spine is injured until proven otherwise. While you open the airway, you must keep cervical spine immobile.