Shock Flashcards
What is shock?
Inadequate circulation to meet the metabolic demands of tissue
Why are children susceptible to fluid loss
Require much higher fluid intake per kg of bodyweight due to higher surface area to volume ratio and higher BMR
When may children become dehydrated?
Unable to take oral fluids
Additional fluid losses due to fever, diarrhoea, or increased insensible losses - tachypnoea, sweating
Loss of normal fluid retaining mechanisms - burns, increased urinary losses or capillary leak
What are early features of shock?
Compensated Tachypnoea Tachycardia Decreased skin turgor Sunken eyes/fontanelles Delayed capillary refill (>2s) Mottled pale cold skin Core peripheral temperature gap >4 Decreased urine output
What are late features of shock
Decompensated Kussmaul's respiration - acidotic Bradycardia Confusion, depressed cerebral state Blue peripheries Absent urine output Hypotension
What is initial management of shock
Fluid resuscitation - 20ml/kg
0.9% saline
Blood if following trauma
Deficit, maintenance and ongoing losses need to be replaced
If improvement, correct hypovolaemia
If no improvement, try again and then ICU
What are the fluid requirements in children?
First 10kg - 100ml/kg
Second 10kg - 50ml/kg
Subsequent kg - 20ml/kg
Per 24h
How much fluid does a 7kg infant, 18k child and 42 kg child require?
7kg infant - 700ml/day
18kg child - 1400ml/day
42 kg child = 1940ml/day
What is subsequent management if there is progression of shock and respiratory failure
ICU
Tracheal intubation and mechanical ventilation
Invasive BP monitoring
Inotropic support
Correction of haematological, metabolic derangements
Support for renal failure
How do you calculate fluid deficit?
Percentage dehydration x weight (kg) x 10
= mls required
How quickly should you replace adeficit if >5% dehydrated?
over 48h
What is mild dehydration?
0-5% 5% weight loss in infants, 3% in children Dry mucous membranes Reduced skin turgot May have decreased urine outpu
What id moderate dehydration?
5-10% Weight loss 10% in infants, 6% in children Decreased skin turgor Very dry mucous membranes Oligouric Tachycardia Capillary refill > 2 seconds Lethargy Hoarse cry
What is severe dehydration?
>10% Weight loss of 15% in infants, 9% in children Skin turgor reduced with tenting Mucous membranes parched Anuric Shock Hypotension Comatose
How are fluids replaced in mild dehydration
Fluid little and often - 5ml every 5 min by syringe
How are fluids replaced in moderate dehydration
Give IV maintenance requirements + deficit over 48 hours
Oral rehydration salts by NG tube if tolerated
Monitor U&E
Measure and replace ongoing losses
How are fluids replaced in severe dehydration
0.9% saline 20ml/kg IV bolus
Continue with saline boluses then use blood until the signs of shock ease
Daily requirements + fluid deficit as above making good continuing loss with 0.45% or 0.9% saline depending on type of dehydration:
- 0.45% in isotonic/hyponatraemic
- 0.9% in hypernatraemic as cerebral oedema is a risk during rehydration with increased serum sodium so correct slowly.
Measure U&E
Raising serum sodium too quickly may cause CPM
