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)
Symptoms of severe dehydration?
Two or more of the following:
1. Lethargy or unconsciousness
2. Sunken eyes
3. Unable to drink or drinks poorly
4. Skin pinch goes back very slowly (≤ 2s)
Management of severe dehydration in infants (<12 months)?
Give 100mg/kg of Ringers lactate or Normal saline divided as follows:
1. first give 30mls/kg in 1 hour
2. then give 70mls/kg in 5 hours
- Repeat once if radial pulse is still weak or not detectable
- Reassess every 15- 30min
- Reassess after 6 hours to reclassify the dehydration as C, B or A
Management of severe dehydration in children (12 months to 5 years)?
Give 100mg/kg of Ringers lactate or Normal saline divided as follows:
1. first give 30mls/kg in 30 minutes
2. then give 70mls/kg in 2.5 hours
- Repeat once if radial pulse is still weak or not detectable
- Reassess every 15- 30min
- Reassess after 6 hours to reclassify the dehydration as C, B or A.
Symptoms of some dehydration?
Two or more of the following signs:
1. Restlessness, irritability
2. Sunken eyes
3. Drinks eagerly, thirsty
4. Skin pinch goes back slowly
Management of some dehydration?
- Give the recommended amount of ORS in the clinic over 4 hours
- Give ORS frequent small sips from a cup. If the child wants more ORS than shown, give more
- If vomits, wait 10 minutes, then continue, but more slowly
- Continue breastfeeding whenever the child wants
- After 4 hours, reassess, classify him and select a appropriate treatment plan
Describe the amount of ORS that is given in management of some dehydration by age?
- <4 months (<6kg) = 200-400 ml
- 4-<12 months (6-<10kg) = 400-700ml
- 12 months to <2 years (10-<12kg) = 700-900ml
- 2 years to <5 years (12-19kg) = 900-1400ml
Four rules of home treatment for some dehydration?
- Give extra fluid
- Give zinc supplements
- Continue feeding
- Know when to return to the clinic
Management of Diarrhea with no dehydration?
- Breastfeed frequently
- Give ORS or food based fluids (soups, rice water, yoghurt)
≤ 2 years: 50 -100mls after each loose stool
≥ 2 years: 100-200mls after each loose stool - Zinc supplements
≤ 6months: 10mg/day for 10-14 days
≥ 6 months : 20mg/day for 10-14 days
Factors affecting fluid replacement?
- Syndrome of inappropriate ADH secretion
- Congestive heart failure
- Renal failure
- Fever
- Hyperventilation
- Severe Acute Malnutrition
Calculating maintenance fluid volume per day?
first 10kg: x100mls/kg/day
second 10kg: x50mls/kg/day
each additional kg: x20ml/kg/day
Calculating maintenance fluid volume per hour?
first 10kg: x4ml/kg/hr
second 10kg: x2ml/kg/hr
each additional kg: 1ml/kg/hr
When to give maintenance fluids?
Indicated in children who cannot be fed enterally
What are maintenance fluids?
- Estimates the volume required per kg to maintain hydration in healthy children
- Accounts for insensible losses (from breathing, through the skin)
- Allows for excretion of the daily excess solute load (urea, creatinine, electrolytes, etc) in a volume of urine with similar osmolarity to plasma
Maintenance fluids does not include?
- Replacement for ongoing losses (diarrhea, vomiting drainage)
- Deficit replacement(dehydration)
Composition of maintenance fluids?
- Electrolytes
- sodium, potassium, and chloride - Water
- Glucose
- provides 20% of normal caloric needs, prevents starvation ketoacidosis and diminishes the protein degradation that would occur if the patient received no calories
