Shock: it’s a state of hypoperfusion
Pathophysiology of shock:
Compensatory mechanism: Increase Cardiac output
- By stimulation of the sympathetic nervous system cause increase Heart rate, stroke volume(SV) and peripheral vascular resistance(PVR).
- Re-distributing the Blood circulation to the vital organs
- Increase O2 delivery to the cells by Bronchodilation, increase respiratory rate and tidal volume.
Stages of shock:
Initial stage (The first stage of hypoperfusion)
- What happens in this stage: decrease of intravascular fluid Lead to hypoxemia and this will Lead to decrease ATP Production, cell membrane damage will occur and become leaky to extracellular fluids.
- Intracellular fluids shift to the extracellular (Interstitial) space.
- cells will perform lactic acid from anaerobic respiration and this will lead to metabolic acidosis.
This stage has neural, How to deal with the shock, hormonal and biochemical mechanism this mechanism describe like:
- Hyperventilation to wash CO2 and decrease metabolic acidosis.
- The adrenal gland secretes epinephrine and norepinephrine to increase Heart rate and Blood Pressure.
- Renin-angiotensin vasopressin cause to conserve fluid via the kidney which Leads to decrease urine output.
Signs & symptoms of this stage:
- LOC(lethargy, confusion).
- Mild tachycardia
- Cool, clammy skin, delayed Capillary refill.
- Normal slightly elevated Blood Pressure.
- Rapid shallow respiration.
- progressive State (Decompensatory State)
What happens in this stage
- Decrease Blood flow Leads to anaerobic respiration which will Lead to metabolic acidosis.
- Precapillary sphincter constriction, Blood will remain in capillaries Which will Lead to increased hydrostatic Pressure Histamine release will increase cell wall permeability and will leak Protein from cells to the extracellular space Blood viscosity will increase and will sliding Microcirculation, this will lead to vital organ hypoperfusion.
Signs & symptoms:
- HR: Moderate tachycardia, weak thready pulse.
- LOC: confusion or unconsciousness.
- Skin: Delayed Capillary refill, cold clammy skin, and cyanosis. (late stage of hypoxia).
- Respiration: Rapid shallow.
- Blood Pressure: Decrease.
Refractory stage: (Irreversible stage)
At this stage, vital organs have failed and shock can be no longer reverse.
Brain damage and cell death have occurred, and death has occurred, and death will occur.
Signs & symptoms
- Bradycardia, sever dysrhythmia.
- LOC : Coma.
- Skin: pale, cold, marked dia phoresis.
- Blood pressure: Marked hypotension (40/20).
Management of shock
- C: STOP bleeding, check the pulse.
- A: Airway open.
- B: Breathing, Look, listen, feel, oxygen.
- Assess vital Signs.
- Put the patient in the shock position
- Administer o2 high concentration.
- IV cannula large cannula (16,14)and fluid (Ringer lactate or N/S).
- Blood sample
- Blood transfusion( O – negative is the best choice for top urgent cases).
- Re to Assess the pt.
- Cover the patient to prevent hypothermia
1- Hypovolemic shock :
It’s the most common type of shock, which is insufficient circulatory volume.
Causes like ( Bleeding, severe diarrhea, severe vomiting, severe burn).
Signs & Symptoms:
Anxiety, restlessness, decreased cerebral perfusion.
Hypotension, Rapid weak pulse, tach cardia.
Cool clammy skin, rapid shallow breathing.
Hypothermia, thirst dry mouth & fatigue.
2- Cardiogenic shock:
It Caused by heart failure to pump effectively.
Causes: Myocardial infarction(MI), congestive heart failure(CHF), Cardiomyopathy, a valve problem, arrhythmia.
Signs & Symptoms: Similar to hypovolemic shock&plus
- Distended jugular veins.
- Increased jugular vein Pressure.
- Absent pulse
3- Distributive shock:
It’s a type of shock, which means insufficient Intravascluare fluid.
- Septic shock.
- Neurogenic shock.
- Anaphylactic shock.
4- Septic shock.
5- Anaphylactic shock.
6- Neurogenic shock.
- Cardiac Tamponade.
- Tension Pneumothorax.
- Pulmonary embolism.
Obstructive shock :
Caused by physical obstruction of great vessels of the heart itself like:
- Tension Pneumothorax.
- Cardiac Tamponade. Pulmonary embolism.
- CAB(check pulse, open airway, Look, lestin, feel, o2admininstration).
- Drugs(Norepinephrine, dopamine).
- PCI (percutanous coronary intervention).
- Treat the cause by Medical surgical_interventions like(CABG).