Pediatric Dehydration

1. Pediatric Dehydration Marc Francis FRCPC Emergency R4 PEM Fellow year 1 Preceptor – Dr Phil Ukrainetz

2. Objectives • Background to dehydration, diarrhea and vomiting • Approach to the dehydrated patient • Case based review of the evidence for the above approach • A sodium review (sorry!!!) • Series of practical cases to enforce your new evidence based approach

3. Pediatric Dehydration • Questions, discussion and random humour to be inserted by Dr Ukrainetz

4. Sick kids = decreased intake Higher percentage TBW Neonate 75% Child 65% Adult 60% Fever increases fluid needs Higher metabolic rate in kids less tolerance to fluid and electrolyte changes Poor renal concentration mechanisms at young age Why is this a peds problem?

5. Dehydration is not a disease 1) Decreased intake 2) Increased output • Insensible losses • Renal losses • GI losses 3) Translocation • Burns • Ascites

6. Causes of Dehydration • Diarrhea • Vomiting • Gastroenteritis • Stomatitis or pharyngitis • Febrile illness • DKA • DI • Burns

7. Diarrhea • Leading cause of death worldwide in children < 4yo • Diarrhea in the United States • 300 children < 5yo die per year • 2-3 million office visits • 200,000 hospitalizations • In North America • children < 5yo have on average 2 episodes of gastroenteritis per year • Costs > 2 billion/year

8. Diarrhea • DDx • Gastroenteritis • Malabsorption • IBD • IBS • Drug side effects • Thyrotoxicosis • Infections • Endocrine disorders

9. Indications for stool studies Toxic appearance Immunocompromised Bloody or invasive Duration > 5days Suspected parasites Travel Camping Poor Water Etiology Viral 60% Bacterial 20% Parasites 5% Parental illness 10% Unknown 10% Diarrhea

10. Vomiting “Vomiting without diarrhea should prompt a thorough search for another cause other than gastro”

11. GI Obstruction Pancreatitis Appy Pyloric stenosis Volvulus Intussusseption GU UTI Pyelo RTA Toxic Drug ingestion Drug side effects ID Pneumonia Sepsis Endocrine Addisons CAH Neuro Meningitis/Encephalitis ↑ ICP Vomiting

12. Case #1 • 5 mo Male • HPI • Non-bloody profuse watery stool 7 days • 10-15 stools per day – foul smelling • Child eager to take water until this AM • Now less interested in drinking and more lethargic • Exam • Quiet and tachypneic • Sunken eyes and a dry mouth • Tachycardic at 165 bpm • Cap refill is 3 seconds • Skin turgor prolonged

13. Case #1 • How do you want to manage this patient? • What are some of the potential pitfalls in managing this patient? • Do you have an approach to this patient? • Would you like one?

14. Approach to Peds Dehydration • Initial Resuscitation • Determine % dehydration • Define the type of dehydration • Determine the type and rate of rehydration fluids • Final considerations The gospel according to Rob Hall

15. Approach to Peds Dehydration • Initial Resuscitation • Determine % dehydration • Define the type of dehydration • Determine the type and rate of rehydration fluids • Final considerations

16. Initial Resuscitation • ABCs • Initial fluid bolus • 20cc/kg of NS or Ringers • Appropriate in all types of dehydration • Reassess q5mins and repeat x 3 • Initial hypoglycemia • 5cc/kg of D10W in infants • 2cc/kg of D25W in children • Think about Shock DDx if unresponsive to 3 attempts at NS bolus

17. Initial Resuscitation • Fluid Controversy… • Theoretical risk of acidosis with NS • “Dilutional acidosis” with addition of NaCl to the extracellular fluid • Ringers lactate has some HCO3 • Harder to find in our department • Potential delay in fluid resuscitation • No evidence to guide you

18. Approach to Peds Dehydration • Initial Resuscitation • Determine % dehydration • Define the type of dehydration • Determine the type and rate of rehydration fluids • Final considerations

19. Case #2 • 20 mo F • HPI • 2 days of vomiting and diarrhea • Not eating and will not drink • 8 stools today but dad does not think there were any diapers with urine in them • Afebrile • Exam • Appears mildly ill • Tears + • Vitals are normal including RR • Mouth is Dry • Cap Refill time is 2.0 seconds

20. Survey • How dehydrated is this child? 3-5% 6-9% >10% • Who wants to do bloodwork? • Who wants to start an IV to rehydrate?

21. Determine % Dehydration • The CPS, AAP, CDC and WHO all have treatment guidelines for gastroenteritis • These are based on the clinical assessment of dehydration • Mild <5%, Moderate 6-9%, Severe >10% • Gold standard is pre and post weight • What are the markers that we use to assess this? • Clinical • Laboratory • How reliable and precise are these markers?

22. Determine % Dehydration

23. What are the best clinical markers? • Prolonged cap refill • Sunken eyes • Poor overall appearance • Sunken fontanelle • Absent tears • Increased HR • Weak Pulse • Dry mucous membranes • Abnormal resp pattern • Abnormal skin turgor or tenting

24. Tenting

25. Systematic review • precision and accuracy of symptoms, signs and lab tests for evaluating pediatric dehydration ≥ 5% • 1603 potential articles • 26 contained the original data required • 13 were eliminated due to lack of diagnostic standard or limited study design

26. Results • Large variability in observations and elicited signs • Ranging from chance to good agreement

28. Conclusions • Tests are imprecise with only fair to moderate agreement • The best 3 individual examination signs were: • Prolonged Cap refill time • Abnormal Skin turgor • Abnormal resp pattern

29. Validity and reliability of clinical signs in the diagnosis of dehydration in childrenGorelick MH, et al. Pediatrics 1997;99:E6 • Prospective cohort study • Urban pediatric hospital ED • N= 186 children • Age range 1 month to 5 years • With diarrhea, vomiting, or poor oral fluid intake • admitted or followed as outpatients • The diagnostic standard for dehydration was fluid deficit as determined from serial weight gain after treatment

30. All children were evaluated for 10 clinical signs before treatment Decreased skin turgor Cap refill time >2 sec General appearance Absence of tears Abnormal respirations Dry MM Sunken eyes Abnormal radial pulse Tachycardia >150bpm Decreased urine output Validity and reliability of clinical signs in the diagnosis of dehydration in childrenGorelick MH, et al. Pediatrics 1997;99:E6

31. Validity and reliability of clinical signs in the diagnosis of dehydration in childrenGorelick MH, et al. Pediatrics 1997;99:E6 • Results • 63 children (34%) had dehydration • defined as a deficit of 5% or more of body weight • At this deficit, clinical signs were already apparent (median = 5) • Individual findings had generally low sensitivity and high specificity • parent report of decreased urine output was sensitive but not specific

32. Validity and reliability of clinical signs in the diagnosis of dehydration in childrenGorelick MH, et al. Pediatrics 1997;99:E6 • Results: • For detection of ≥ 5% dehydration • Presence of 3 or more signs Sensitivity of 87% Specificity of 82% Positive LR of 4.9 (3.3-7.2) • Presence of 7 or more signs Positive LR 8.4 (5.0-14.3)

33. Validity and reliability of clinical signs in the diagnosis of dehydration in childrenGorelick MH, et al. Pediatrics 1997;99:E6 • Further logistic regression analysis showed most of the predictive power was in the following 4 signs • Prolonged cap refill • Dry MM • Absence of tears • Abnormal appearance • 2/4 had positive LR of 6.1 (3.8-9.8)

34. Validity and reliability of clinical signs in the diagnosis of dehydration in childrenGorelick MH, et al. Pediatrics 1997;99:E6 • Conclusions • Conventionally used clinical signs of dehydration are valid and reliable • Individual findings lack sensitivity • Diagnosis of clinically important dehydration should require at least three clinical findings

35. You see a 17 month old child with a 3 day history of non-bloody D/V Your clinical assessment is that he is only mildly dehydrated You discover the CC has sent bloodwork prior to your arrival: ABG 7.34/33/84/17 Na 133 Cl 103 K 3.5 Cr 34 BUN 4.2 mmol/L Case #3

36. Determine % Dehydration • Does lab work help you in determining the degree of dehydration? • What lab values do people use to assess severity of dehydration?

37. Results

38. Conclusions • Tests such as BUN and bicarbonate are only helpful when results are markedly abnormal • A normal bicarbonate concentration reduces the likelihood of dehydration • No lab test should be considered definitive for dehydration

39. Approach to Peds Dehydration • Initial Resuscitation • Determine % dehydration • Define the type of dehydration • Determine the type and rate of rehydration fluids • Final considerations

40. Case #4 • 6 day old Female • First child born at term • GBS negative mother • Normal preg and delivery D/C’d within 24 hrs • Exclusively breastfed • HPI • Mom says child is a “poor feeder” • Not sure if her breastmilk has come in fully • Child much more listless today • Having to wake to feed • No urine output or stools noted in the last 48hrs

41. Case #4 con’t • Exam • Vitals = HR 160, RR 38, T36.9°C, Sats 94%, BG4.1 • Generally – difficult to rouse but irritable upon awakening • CVS – normal pulse and cap refill • Resp – clear • Hydration – MM dry, no tears noted, skin is noted to be very soft and doughy

42. Labs CBC WBC 4.8 Hgb 179 Plt 433 Lytes Na 167 K 6.8 Cl 132 Bicarb 16 BUN = 7mmol/L Creatinine = 90umol/L What type of dehydration is this? What is the most likely cause? Case #4 con’t

43. Define the type of dehydration • Three major classes of dehydration based on relative losses of Na and Water • Isonatremic dehydration (80%) • Hypernatremic dehydration (15%) • Hyponatremic dehydration (5%) Thanks to Rob Hall for any details

44. Body Fluids ICF (mEq/L) ECF (mEq/L) • Sodium 20135-145 • Potassium 150 3-5 • Chloride --- 98-110 • Bicarbonate 10 20-25 • Phosphate 110-115 5 • Protein 75 10

45. 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

46. 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 • Alternating between lethargy and hyperirritability

47. Hypernatremic Dehydration • Physical findings • Dry doughy skin • Increased muscle tone • Correction • Correct Na slowly • If lowered to quickly causes • massive cerebral edema • intractable seizures

48. 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

49. Hyponatremic Dehydration • Correction • Must again be performed slowly unless actively seizing • Rapid correction of chronic hyponatremia thought to contribute to…. Central Pontine Myelinolysis • Fluctuating LOC • Pseudobulbar palsy • Quadraparesis

50. Approach to Peds Dehydration • Initial Resuscitation • Determine % dehydration • Define the type of dehydration • Determine the type and rate of rehydration fluids • Final considerations