how to assess dehydration, the plane of treatment

1. Dehydration
Dr. Muhammad Isaac m. suliman
MBBS
Portsudan emergency teaching hospital
Sudan
10/Jan/2021

2. Content :
• Definition & overview
• Pathophysiology & Types
• Causes
• Assessment
• Management
• Complication
• Problem solving

3. Overview
Water is essential element of the body ..up to
75% of the body weight
Water is found in :
- Intracellular space
- Extravascular space
- Interstitial space
- Water balance : input is equal to output

4. Definition
• Deficit of total body water, with accompanying
disruption of metabolic processes
• This occur when amount of water leaving the
body is greater than the amount being taken
in
Output > Input

5. Pathophysiology
Decrease intravascular volume
I
Decrease venous return
I
Decrease ventricular filling
I
Decrease stroke volume
I
Decrease cardiac output
I
Inadequate tissue perfusion

7. Types of dehydration
• Depending on the metabolic derangements there is three
types :
A- isotonic dehydration : balanced deficit of water & sodium
- Hypovolemia due to loss of ECF
- serum Na 135 – 155 mmol/l
B- Hypertonic dehydration : loss of water in excess of sodium
eg salty food + Diarrhea
- deficit of H2O > Na
- serum Na > 155mmol/l , osmolalaty > 295mOsmol/l
- seizures occur when serum Na exceed 165mmol/l

8. Types of dehydration
C- Hypotonic dehydration : when replace losses
by hypotonic fluids eg water or D5% in water
IV
- deficit of sodium > H2O
- serum Na < 130mmol/l , osmolaty <
275mOsmol/l

9. Based on severity of dehydration :
• Mild : Fluids loss reach 5% or less
• Moderate : Fluids loss between 5 – 10%
• Sever : the total loss reaches more than 10%
of body weight ( emergency case )

10. Causes
• Excessive fluids loss , reduce fluids intake ,
third-space fluid shift , or a combination of
these factor can cause fluid volume losses :
• Related to intake
• Related to loss
• Translocation

11. Other causes :
• Vomiting or diarrhoea
• Diabetes mellitus with polyuria or diabetes
insipidus
• Fever
• Acute renal failure with polyuria
• Excessive perspiration
• Hemorrhage
• Surgery eg abd.s , NG drainage , GI suction
• Drugs eg diuretics & laxatives
• Excessive fluid removal with dialysis

12. Assessment
sever
moderate
mild
> 10 %
6 – 10 %
3 – 5 %
Weight loss
shock
orthostatic
normal
Blood pressure
tachycardia
increase
normal
pulse
lethargic
irritable
normal
Behaviour
parched
dry
moist
Membranes
absent
decrease
present
Tears
> 4 seconds
2 – 4 seconds
2 seconds
Cap. Refill
anuria
oligouria
Normal or low
Urine amount

13. Other :
• Thirsty or unable to drink
• Decrease skin turgur
• Sunkun eyes
• Sunkun ant. Fontanella
• Cool extremities
• Deterioration of consciousness
• Circulatory collapse
• Death

14. Management
• Depends on age , weight , severity of
dehydration and its cause.
• Oral rehydration solution (ORS) for mild &
moderate dehydration
• IV fluids replacement for sever dehydration
• Treating the cause of dehydration

15. Mild & Moderate manage :
• Oral rehydration solution (ORS)
• Easy way to rehydrate after losses composed of :
- 30 ml of sugur
- 2.5 ml of salts
- 1 liter of water
• Amount : weight X 5ml
• Each loss 50 – 100 ml replace or 100 – 200 if age > 2 years slowly
rehydrate 1 – 2 teaspoon every 2 minute
• Contraindication for ORS :
1- Sever dehydration
2- unconsciousness
3- frequent vomiting attack
• Continues breastfeeding
• Zofran or omeprazol to ttt nausea & vomitus

16. Some dehydration ttt:
• ORS
75 ml / kg body weight in 4 – 6 hours
Continue breast feeding in between if not 100 –
200 ml clean water given during ORS therapy
- Reassessment : no dehydration go to plan A
Some dehydration continue plan B
Losses + sign of sever dehydration plan C

17. Daily Fluids Requirements
How to calculate the maintenance ?

18. Sever dehydration ttt :
NPO
IV Fluids replacement ( Plane C )
Indication of IV Fluids :
Sever dehydration
Failure of oral rehydration
Shock
Paralytic ileus or DIC
• Types of fluids :
- Ringer lactate
- D5% ½ NS
- IV poly electrolyte solution
- Pansol
• Amount : 100 ml / kg body weight

19. Sever dehydration ttt :
• Rate :
• - If less than 1 year 30% in 1 hour, 70% in 5 hours
- If more than 1 year 30% in 30 minute , 70% in 2& ½
hours
• Pt should assessd hourly for response :
- Return of strong radial pulse
- Improve level of consciousness
- Ability to drink
- Pass of urine normal amount
- Improve skin turgor
• Increase rate & volume if no improvement

20. Malnurished child rehydration :
• Is oraly or by NG tube
• Types of fluids :
- Resomal
- Ringer lactate + D5% ( 1 : 1 ) Ratio
• Rate : rehydration in 12 hours
- First two hours 10 ml /kg / hour
- Then 5 – 10 ml / kg /hour for 10 hours
• IV Fluids in shock only return to oral after
management of the shock

21. Complication
• Hypovolemic shock
• Seizures ( Hyponatremia , Hypernatremia )
• Kidney injury
• Perminant brain damage
• Coma & death

22. Problem solving
• HX Tudai is a 24-month-old boy with Down’s
syndrome, brought to the A&E department by his
mother. He has had diarrhoea and vomiting for 1 day.
In the last 8 hours, he has drunk 200 ml milk, vomited
five times and passed six liquid stools. The vomit is not
bilious and there is no blood or mucus in the stools. It
has been hard to tell if he is passing urine because
every nappy is soiled. He has no cardiac problems and
no other medical problems except glue ear. There is no
history of foreign travel. His two older siblings have
recently had diarrhoea and vomiting.

23. Examination
• He is miserable and lethargic. His heart rate is 120
beats/min, respiratory rate is 25 breaths/min, and his
temperature is 37.7C. He has dry mucous membranes,
his eyes are slightly sunken, his skin turgor appears
normal and his capillary refill time is less than 2 s. His
abdomen is soft with no masses palpable. His weight is
11 kg (50th centile on the Down’s syndrome growth
chart). An oral fluid challenge is commenced in the
emergency department. He drinks 60 ml of electrolyte
solution over 2 hours and vomits once on the floor. He
does not pass urine into a urine bag during this period

24. Questions :
• What is the most likely diagnosis?
• How dehydrated is this child?
• How would you manage this child now?
• How would you calculate the fluid
requirements for this child over the next 24
hours?

25. Note :
• Fluid requirement for 24 hours = maintenance
+ correction of deficit + replacement of
ongoing losses .

26. THANK YOU !