Shock and Dehydration Flashcards
What is shock?
Physiologic state characterized by inadequate oxygen and nutrient delivery to meet tissue demands
Features of compensated shock?
- Tachycardia is often the first and most sensitive vital sign change.
- Blood flow is redirected from nonvital organs and tissues to vital organs by a selective increase in systemic vascular resistance (SVR), resulting in reduced peripheral perfusion and decreased urine volume.
- Cardiac contractility increases to maintain cardiac output.
- Increased venous smooth muscle tone improves preload and stroke volume
Features of decompensated shock?
- Perfusion to vital organs is compromised
- Hypotension
- Poor perfusion
- Oliguria/anuria
- Altered mental status
Causes of hypovolemic shock?
- inadequate fluid intake
- increased fluid losses
- hemorrhage
- gastroenteritis
- burns
Causes of shock?
- hypovolemic
- cardiogenic
- distributive
- obstructive
Causes of cardiogenic shock?
- congenital heart disease
- myocarditis
- cardiomyopathy
- arrhythmia
Causes of distributive shock?
- sepsis
- anaphylaxis
- neurogenic
e.g., high cervical spine injury
Causes of obstructive shock?
- tension pneumothorax
- cardiac tamponade
- pulmonary embolism
- ductal-dependent congenital cardiac abnormalities
Symptoms of cardiogenic shock?
- Respiratory distress due to pulmonary edema
- hepatomegaly
- jugular venous distension
- cyanosis
Symptoms of distributive shock?
- Tachycardia, fever, and petechial, purpuric, or urticarial rash.
2.Warm septic shock (bounding peripheral pulses, flash capillary refill, and wide pulse pressure).
3.Cold septic shock (decreased peripheral pulses, delayed capillary refill, and narrow pulse pressure).
4.Neurogenic shock (hypotension with a wide pulse pressure, normal HR or bradycardia, and hypothermia).
Symptoms of hypovolemic shock?
- Tachycardia
- narrow pulse pressure
- delayed capillary refill
- cool extremities
Symptoms of obstructive shock?
1.Initially indistinguishable from hypovolemic shock. Later signs and symptoms similar to cardiogenic shock.
2.Muffled heart sounds and pulsus paradoxus in cardiac tamponade
3.Higher preductal versus postductal BP or arterial oxygen saturation Ductal-dependent lesions
Pathophysiology of hypovolemic shock?
- increased HR
- decreased preload
- normal or increased contractility
- increased SVR
Management of hypovolemic shock?
- Isotonic crystalloid
- Replace blood loss
Pathophysiology of distributive shock?
- increased or decreased HR
- normal or decreased preload
- normal or decreased contractility
Management of distributive shock?
- Isotonic crystalloids to expand intravascular volume
- Vasopressors if fluid-refractory
Pathophysiology of septic shock?
- increased HR
- decreased preload
- normal or decreased contractility
- decreased SVR
Management of septic shock?
- Isotonic crystalloid boluses
- Broad-spectrum antibiotics
- Stress-dose hydrocortisone
- Norepinephrine or high-dose dopamine (warm)
- Epinephrine or dopamine (cold)
Pathophysiology of neurogenic shock?
- normal or decreased HR
- decreased preload
- +/-contractility
- decreased SVR
Management of neurogenic shock?
- Position patient flat or head-down
- Isotonic crystalloid therapyIf fluid-refractory
- Norepinephrine or epinephrine
- Maintain normothermia
Pathophysiology of cardiogenic shock?
- +/- HR
- increased preload
- decreased contractility
- increased SVR
Management of cardiogenic shock?
- Cautious administration (10–20 min) of isotonic crystalloid (5–10 mL/kg); stop if fluid overload develops
- Decrease metabolic demand with oxygen therapy, ventilatory support and antipyretics
Pathophysiology of obstructive shock?
- increased HR
- +/- preload
- normal contractility
- increased SVR
Management of obstructive shock?
- Correct underlying cause
- Prostaglandin E1if ductal-dependent lesion suspected
- Consider initial fluid challenge with isotonic crystalloid (10–20 mL/kg)