Assessment and management of dehydration

1. ASSESSMENT AND MANAGEMENT
OF DEHYDRATION
Dr. Siddharth Mahajan
Guide – Dr. Ashish Vaidya
21/07/2016

2. INTRODUCTION:
• Dehydration resulting from acute diarrheal illness is one of the most
significant causes of morbidity and mortality in the population.
• In some cases, it accounts for more than 50% of the deaths during
the initial stages of a humanitarian emergency.
• Worldwide, over 3 million children under 5 years die from
dehydration every year. (WHO)
• The use of oral rehydration therapy (ORT) has markedly reduced the
morbidity and mortality associated with dehydration caused by
diarrheal illness regardless of the etiology.

3. Lobo ND, Lewington AJP, Allison SP. Basic concept of fluid and electrolyte therapy. Page no-20-30

4. Body Fluid Volumes
Compart
ment
Fluid Vol. (l) % Body Fluid % Body Wgt.
Total Body
Fluid
42 100 60
Intracellular
Fluid
(ICF)
28 67 40
Extracellular
Fluid (ECF)
14 33 20
Plasma 2.8 6.6
(20% ECF)
4
Interstitial
Fluid
11.2 26.4
(80% ECF)
16
Lymph &
Transcellular
Fluid
Neg. Neg. Neg.
Lobo ND, Lewington AJP, Allison SP. Basic concept of fluid and electrolyte therapy. Page no-9-23

5. Normal anatomy and physiology
• Water comprises 60% of the body weight of an
average adult although the percentage is lower in
obesity, since adipose tissue contains less water
than lean tissue.
• The total body water is divided functionally
– Extracellular (ECF = 20% of body weight)
– Intracellular fluid spaces (ICF = 40% of body weight)
– These are separated by the cell membrane with its
active sodium pump which ensures that sodium
remains largely in the ECF
chowdhury AH, Lobo DN. Fluids and gastrointestinal function. Curr Opin Clin Nutr Metab Care
2011;14:469-76

6. Body Water Compartments Related to
Age
0
10
20
30
40
50
60
70
80
0 years 1 year 10 years 20 years
TBW
ICF
ECF

7. Intracellular and Extracellular Fluid
Composition
Intracellular (mEq/L) Extracellular (mEq/L)
Na+ 20 133-145
K+ 150 3-5
Cl- --- 98-110
HCO3
- 10 20-25
PO4
3- 110-115 5
Protein 75 10
% Body weight 80 15 (Interstitial);
5 (Intravascular)

8. Composition of fluids (mmol/l)
Lobo ND, Lewington AJP, Allison SP. Basic concept of fluid and electrolyte therapy. Page no-9-23

9. Normal routes of water gain and loss

10. WATER LOSSES

11. Disturbances of fluid homeostasis
• Disturbance of fluid balance (intake≠output)
– Dehydraton, Overhydration (hyperhydration)
• Disturbance of osmolarity (electrolyte intake≠water
intake)
– Isotonic
– Hypotonic
– Hypertonic
Lobo ND, Lewington AJP, Allison SP. Basic concept of fluid and electrolyte therapy. Page no-9-23

12. DEFINITION:
• Dehydration is a condition that can occur with
excess loss of water and other body fluids.
Dehydration results from decreased intake,
increased output (renal, gastrointestinal or
insensible losses), a shift of fluid (eg, ascites,
effusions), or capillary leak of fluid (eg, burns
and sepsis).

13. Diarrhea
• Definition:
An increase in the fluidity, volume and
frequency of stools. (>3 times/ day)
• Acute diarrhea: Short in duration (less than
2 weeks).
• Chronic diarrhea: 2 weeks or more

14. Etiology of Diarrhea
Acute Diarrhea Chronic Diarrhea
Gastroenteritis Post infections
Systemic infection Secondary disaccaridase deficiency
Antibiotic association Irritable colon syndrome
Overfeeding Milk protein intolerance

15. Types of Diarrhea
• Acute watery diarrhea: (80% of cases)
Dehydration
Malnutrition
• Dysentery: (10% of cases)
Anorexia/weight loss
Damage to the mucosa
• Persistent diarrhea: (10% of cases)
Dehydration
Malnutrition

16. Mechanisms of Diarrhea
• Osmotic
• Secretory
• Exudative
• Motility disorders

17. Mechanisms of Diarrhea
• Osmotic
Defect present:
Digestive enzyme deficiencies
Ingestion of unabsorbable solute
Examples:
Viral infection
Lactase deficiency
Sorbitol/magnesium sulfate
Infections
Comments:
Stop with fasting
No stool WBCs

18. Mechanisms of Diarrhea
• Secretory:
Defect:
Increased secretion
Decreased absorption
Examples:
Cholera
Toxinogenic E.coli
Comments:
Persists during fasting
No stool leukocytes

19. Mechanisms of Diarrhea
• Exudative Diarrhea:
Defects:
Inflammation
Decreased colonic reabsorption
Increased motility
Examples:
Bacterial enteritis
Comments:
Blood, mucus and WBCs in stool

20. Mechanisms of Diarrhea
• Increased motility:
Defect:
Decreased transit time
Example:
Irritable bowel syndrome

21. CLASSIFICATION OF DEHYDRATION SEVERITY BY
WHO
NO DEHYDRATION SOME DEHYDRATION SEVERE DEHYDRATION
Not enough signs to
classify as some or
severe dehydration
•Two or more of the following
signs: restlessness, irritability
•sunken eyes
•drinks eagerly, thirsty
•skin pinch goes back slowly
•Two or more of the
following signs:
lethargy/unconsciousness
•sunken eyes
•unable to drink or drinks
poorly
•skin pinch goes back very
slowly (≥2 seconds)
National Collaborating Centre for Women's and Children's Health (UK). Diarrhoea and Vomiting Caused by Gastroenteritis: Diagnosis, Assessment and Management in Children Younger
than 5 Years. London: RCOG Press; 2009 Apr. (NICE Clinical Guidelines, No. 84.) 4, Assessing dehydration and shock.

23. Degree of Dehydration
Factors Mild
3% (30ml/kg)
5% (50ml/kg)
Moderate
Older Child
6% (60ml/kg)
Infant
10% (100ml/kg)
Severe
9% (90ml/kg)
15% (150ml/kg)
General Condition Well, alert Restless, thirsty, irritable Drowsy, cold extremities, lethargic
Eyes Normal Sunken Very sunken, dry
Anterior fontanelle Normal depressed Very depressed
Tears Present Absent Absent
Mouth + tongue Moist Sticky Dry
Skin turgor Slightly decrease Decreased (1-2 sec) Very decreased (>2sec)
Thirst Normal Drinks eagerly, thirsty Unable to drink or drinks poorly
Pulse (N=110-120
beat/min)
Slightly increase Rapid, weak Rapid, sometime impalpable
BP (N=90/60 mm Hg) Normal Deceased Deceased, may be unrecordable
Respiratory rate Slightly increased Increased Deep, rapid
Urine output Normal Reduced Markedly reduced
Treatment Plan A Plan B Plan C

24. Types of Dehydration
Isonatremic Hypernatremic Hyponatremic
Loses H2O = Na H2O > Na H2O < Na
Plasma osmolality Normal Increase Decrease
Serum Na Normal Increase Decrease
ECV
ICV
Decrease
maintained
Decrease
Decrease +++
Decrease +++
Increase
Thirst ++ +++ +/-
Skin turgor ++ Not lost
(Doughy skin)
+++
Mental state Irritable/lethargic Very irritable Lethargy/coma
shock In severe cases Uncommon Common

25. Isonatremic Dehydration
• By far the most common
• Equal losses of Na and Water
• Na = 130-150
• No significant change between fluid
compartments
• No need to correct slowly

26. Hyponatremic Dehydration
• Sodium loss > Water loss
• Na <130mmol/L
• Water shifts from ECF to ICF
• Child appears relatively more ill
• Less intravascular volume
• More clinical signs
• Cerebral edema
• Seizure and Coma with Na <120
• Increase rate of Sr. Na level should be less
than 0.5 mEq/L (Central pontine myelinolysis)
Lobo ND, Lewington AJP, Allison SP. Basic concept of fluid and electrolyte therapy. Page no-9-23

27. Hyponatremia:
Decreased Weight Increased or Normal
Weight
Renal Losses Extra-renal Losses
Na+ losing nephropathy GI losses Nephrotic syndrome
Diuretics Skin losses Congestive heart failure
Adrenal insuffiency Third spacing SIADH
Cerebral salt wasting
syndrome
Cystic Fibrosis Acute/ Chronic renal failure
Water intoxications
Cirrhosis
Excess salt free infusions

28. Hypernatremic Dehydration
• Water loss > sodium loss
• Na >150mmol/L
• Water shifts from ICF to ECF
• Child appears relatively less ill
• More intravascular volume
• Less physical signs (Dry doughy skin/ Inc. muscle tone)
• Alternating between lethargy and hyperirritability
• Decrease rate of Sr. Na level should be less
than 0.5 mEq/L (Cerebral Edema)
chowdhury AH, Lobo DN. Fluids and gastrointestinal function. Curr Opin Clin Nutr Metab Care
2011;14:469-76

29. Hypernatremia:
Decreased Weight Increased or Normal
Weight
Renal Losses Extra-renal Losses
Nephropathy GI losses Exogenous Na+
Diuretics Skin losses Mineralocorticoid excess
Diabetes insipidus Respiratory Hyperaldosteronism
Post obstructive diuresis
Diuretic phase of ATN

30. Approach to Dehydration
1) Initial Resuscitation
2) Determine % dehydration
3) Define the type of dehydration
4) Determine the type and rate of
rehydration fluids
5) Final considerations

31. Management of Dehydration
• General Principles:
1. Supply Maintenance Requirements
2. Correct volume and electrolyte deficit
3. Replace ongoing abnormal losses

32. 1. Maintenance Volume: Calorie
Calculations
1. Basal Calorie Method
2. Holliday- Segar method
3. Body Surface area method

33. BASAL CALORIE METHOD

34. HOLLIDAY-SEGAR METHOD
C AMY, BILLY S.A. Diagnosis and Management of Dehydration in Children. American Family Physician.
2009,oct;80(7):692-96.

35. BODY SURFACE METHOD:
Should not be used in children < 10kg.
STANDARD VALUES FOR USE IN BODY SURFACE AREA (BSA) METHOD
H2O 1500 ml/m2/24 hr
Na+ 30-50 mEq/m2/24 hr
K+ 20-40 mEq/m2/24 hr
m2 = meters squared

36. 2. Deficit Repletion
• Water deficit Volume:
Water Deficit (L) = Pre-illness weight (kg) - Illness
weight (kg)
% Dehydration = (Pre-illness weight – Illness
weight)/ Pre-illness weight x 100
• Each 1% dehydration corresponds to 10ml/kg
fluid deficit

37. 3. Ongoing Losses
• Regardless of the degree of dehydration,
give additional 10ml/ kg of ORS for each
additional diarrheal stool.

38. • Na+ deficit (mEq) = fluid deficit (L) x proportion
from ECF (0.6) x Na+
conc. (mEq/L) in ECF (145)
• K+ deficit (mEq) = fluid deficit (L) x proportion
from ICF (0.4) x K+ conc. (mEq/L)
in ICF(150)
• Excess Electrolyte Deficits:
mEq required = [conc. desired (mEq/L) – conc.
present (mEq/L) x fluid deficit x weight

39. • Free water deficit: 4ml/kg x pre-illness wt. (kg)
(FWD) x [Conc. present (mEq/L) –
[Conc. desired (mEq/L)]
• Solute fluid Deficit: Total fluid deficit – FWD
(SFD)
– Solute Na+ deficit = SFD (L) x 0.6 x 145
– Solute K+ deficit = SFD (L) x 0.4 x 150

42. Q. 7 kg infant who has been ill for >3 days
clinically appears 10% dehydrated. Current
weight 6.3 kg. Na+ =137mEq/L

44. Q. 7 kg (pre-illness weight) infant ill for > 3 days
clinically appears 10% dehydrated. Current
weight 6.3 kg. Serum Na+ = 115 mEq/L

46. Q. 7 kg (pre-illness weight) infant ill for > 3 days
clinically appears 10% dehydrated. Current
weight 6.1 kg. Serum Na+ = 160 mEq/L

48. Severe Dehydration
• Management of severe dehydration requires
IV fluids.
• Choice of fluid: Normal saline(NS) or Ringer
Lactate (RL)
• Fluid selection and rate should be dictated by
• The type of dehydration
• The serum Na
• Clinical findings
• Aggressive IV NS bolus remains the mainstay
of early intervention in all subtypes

49. Monitoring Therapy
• Vital signs:
– Pulse
– Blood pressure
• Intake and output:
– Fluid balance
– Urine output
• Physical examination
– Weight
– Clinical signs of depletion or overload
• Electrolytes

51. WHO TREATMENT PLANS

52. Plan A (No Dehydration)
Oral rehydration therapy to prevent Dehydration
Age ORT fluids to give Amount of ORS to
after each loose stool provide for use at home
< 24 months 50 - 100 ml 500 ml/ day
2 – 10 years 100 – 200 ml 1000 ml/ day
> 10 years Ad lib 2000 ml/ day
Give Supplemental Zinc (10-20 mg) to the child, everyday for 10 to 14 days

53. Plan B (Some Dehydration)
1. Daily fluid requirement:
– Up to 10 kg = 100 ml/ kg
10 – 20 kg = 50 ml/ kg
> 20 kg = 20 ml/ kg
2. Deficit replacement:
75 ml/ kg ORS to be given over 4 hours
3. Replace losses:
ORS should be administered in volumes equal
to diarrheal losses. Maximum of 10 ml/ kg
per stool.
4. Give Supplemental Zinc (20 mg) to the child,
everyday for 10 to 14 days

54. Plan C (Severe Dehydration)
• Treated with 20 mL/ kg IV of isotonic crystalloid
over 10 to 15 minutes. Repeat as necessary.
• Monitor pulse strength, capillary refill time, mental
status, urine output and electrolytes.
• After resuscitation: A total of 100 ml/ kg of fluid
given over 3 hours in children > 12 months and
over 6 hours in children < 12 months.
• Assess the patient every 3 hours accordingly repeat
Plan C or shift to Plan B
Age 30 ml/ kg 70 ml/ kg
< 12 months 1 hour 5 hour
> 12 months 30 min 2 ½ hour

55. ORS Mechanism
• In normal physiological state, water is absorbed osmotically
across the small bowel through tight junctions between
epithelial cells due to a sodium gradient that is maintained
by 2 mechanisms of sodium absorption in the brush border
membrane of the luminal cell:
– passive sodium/potassium diffusion
– active co-transport of sodium jointly with monosaccharides
such as glucose.
• In diarrheal illness, the passive absorptive mechanism of
sodium and chloride is impaired, but glucose absorption
remains largely intact. This allows the absorption of enough
water and sodium to compensate for fluid losses as
significant as those seen in cholera.

57. ORS
Constituent g/
L
Osmole / ion mmol/ L
Sodium
chloride
3.5 Sodium 90
Glucose 20 Glucose 111
Potassium
chloride
1.5 Potassium 20
Trisodium
citrate
2.9 Citrate 10
Chloride 80
Total
Osmolarity
311
Constituent g/L Osmole/ion mmol/L
Sodium
chloride
2.6 Sodium 75
Glucose 13.5 Glucose 75
Potassium
chloride
1.5 Potassium 20
Trisodium
citrate
2.9 Citrate 10
Chloride 65
Total
Osmolarity
245
STANDARD WHO ORS LOW OSMOLARITY ORS

58. ADVANTAGES OF LOW OSMOLARITY
ORS
• Promotes more effective water and sodium
absorption.
• No additional risk for hypernatremia.
• Better acceptability due to taste
• Decreases volume, purge rate and duration of
diarrhea.
• More stability of reconstituted solution.
• Single formulation promoted for all ages,
irrespective of etiology or nutrition status.

59. Cereal based ORS/ Rice based ORS
• Super ORS
• Superior to WHO ORS in efficacy in patients
with cholera.
• Similar efficacy in non- cholera diarrhea
• Advantages:
– Decreased purge rate
– Slow release of glucose from starch

60. Other types of ORS
• ReSoMal: Rehydration Solution in severely
Malnourished children with dehydration.
• Potassium deficiency but have high Sodium.
• Deficiency of magnesium, zinc and copper.
• Contents:
– Potassium: 40 mEq/ L
– Sodium: 45 mEq/ L
– Magnesium, zinc, copper.

61. Dehydration in Severe Malnutrition
• With some or severe dehydration but who are
not shocked should be rehydrated slowly, either
orally or by nasogastric tube.
• ReSoMal: Rehydration Solution in severely
Malnourished children should be used.
• 5ml/ kg Resomal every 30 mins for first 2 hrs.
• If still dehydrated, 5-10ml/kg/hr should be given
in alternate hours with F-75 for max 10 hrs.
• Signs of improved hydration status and
overhydration checked every half hour for first 2
hrs then hourly.

62. • Children with SAM and signs of shock or severe
dehydration and who cannot be rehydrated
orally or by NG tube should be treated with IV
fluids 15ml/kg/hr.
• Half strength darrow’s soln. with 5% dextrose
Ringer lactate solution with 5% dextrose.
• Monitor child every 5 – 10 mins for signs of
overhydration and signs of CCF.
• If child does not improve with 1 hr of IV fluid,
blood transfusion 10ml/kg slowly over 3 hours.
WHO. Guideline: Updates on the management of severe acute malnutrition in infants
and children. Geneva, World Health Organization; 2013

63. Other types of ORS
• Zinc fortified ORS
• ORS fortified with amino acids.
• Home made ORS
– 4g salt + 40g sugar in 1 L of water

64. Contraindications to ORT
• Ileus or intestinal obstruction
• Unable to tolerate (Persistent vomiting)

65. Home available fluids
Acceptable Home available Fluids
Fluids that contain Salt (Preferable) ORS, Salted drinks (Salted rice water/
salted yogurt drink), vegetable or chicken
soup with salt
Fluids that do not contain salt
(Acceptable)
Plain water, water in which cereal has
been cooked, unsalted soup, yogurt
drinks without salt, green coconut water,
weak unsweetened tea, unsweetened
fresh fruit juice
Unsuitable home available fluids Commercial carbonated beverages,
commercial fruit juices, sweetened tea.

66. THANK YOU