General Pediatrics Board ReviewNephrology

Fluids and ElectrolytesAcid-Base

UTIHypertension

Jeffrey M. Saland, M.D.Chief, Nephrology and HypertensionDepartment of PediatricsIcahn School of Medicine at Mount Sinai

Summer Board Review

I Don’t Decide What’s On the Boards

4

An 8 year old proudly announces to you that she did a report on jellyfish and they are 96% water. She asks you what is her “percent water?” What is the best estimate of her fluid compartments by percent of body weight?

Total Body Water

Extracellular Fluid

Intracellular Fluid

A. 80% 45% 35%

B. 70% 30% 40%

C. 60% 20% 40%

D. 50% 20% 30%

E. Same as the jellyfish

5

An 8 year old proudly announces to you that she did a report on jellyfish and they are 96% water. She asks you what is her “percent water?” What is the best estimate of her fluid compartments by percent of body weight?

Total Body Water

Extracellular Fluid

Intracellular Fluid

A. 80% 45% 35%

B. 70% 30% 40%

C. 60% 20% 40%

D. 50% 20% 30%

E. Same as the jellyfish

6

Composition of Body Fluids

Babies are moist– but not quite jellyfish!

7

Finberg L. Water and Electrolytes in Pediatrics 1993 (data from Friis-Hansen BJ Pediatrics 1961)

ICW

ECW

TBW

8

Age Total Water ECW ICW0-1 day 79 43.9 35.1

1-10 days 74 39.7 34.3

1-3 mo 72.3 32.2 40.1

3-6 mo 70.1 30.1 40

6-12 mo 60.4 27.4 33

1-2 yr 58.7 25.6 33.1

2-3 yr 63.5 26.7 36.8

3-5 yr 62.2 21.4 40.8

5-10 yr 61.5 22 39.5

10-16 yr 58 18.7 39.3

Distribution of body water as a percentage of body weight

Compiled by Finberg, L. from data by BJ Friis-Hansen, Acta Paed Scand 1958Technique: D2O for TBW and thiosulfate for ECW

9

TBW = 60% Lean Body Mass:

Approx Body Composition > 1 year

ICF = 2/3 TBWECF = 1/3 TBWPlasma = 1/4 ECF(rest is interstitial fluid)

Na ~ 13K ~ 140

Na ~ 140K ~ 4

Pla

sm

a

ICF

ECF

TBW

10

A previously healthy 23 kg child is admitted for gingivostomatitis and refusal of oral intake. What is the most appropriate maintenance intravenous fluid prescription?

Base Potassium Rate

A. 0.9% NS None 65 ml/hr

B. D5 ½ 0.9% NS 20 mEq/L 100 ml/hr

C. D5 ½ 0.9% NS 20 mEq/L 65 ml/hr

D. D5 W 20 mEq/L 50 ml/hr

E. D5 ¾ 0.9% NS 20 mEq/L 65 ml/hr

11

A previously healthy 23 kg child is admitted for gingivostomatitis and refusal of oral intake. What is the most appropriate maintenance intravenous fluid prescription?

Base Potassium Rate

A. 0.9% NS None 65 ml/hr

B. D5 ½ 0.9% NS 20 mEq/L 100 ml/hr

C. D5 ½ 0.9% NS 20 mEq/L 65 ml/hr

D. D5 W 20 mEq/L 50 ml/hr

E. D5 ¾ 0.9% NS 20 mEq/L 65 ml/hr

12

What are maintenance fluids?

The fluid and electrolytes necessary for a person to remain in net balance over the long term

ICF ECF

Pla

sm

aINTAKE

OUTPUT

13

Sounds Easy!

14

What are maintenance fluids?

Barratt M: Pediatric Nephrology 4th Ed 1998

15

What are maintenance fluids?

Why did that graph estimate caloric needs?

We need to know how many mL of fluid to order, not how many calories!

16

Insensible losses:respiratory 30 cc / 100 Cal+ evaporative not sweat 15 cc / 100 Cal

45 cc / 100 Cal

Urine output losses 50-75 cc / 100 CalStool losses 5-10 cc / 100 CalGrowth “loss” 0-15 cc / 100 Cal

Water of oxidation (a gain) 10-15 cc / 100 Cal

TOTAL Approximately 100 cc / 100 Cal

For the “average” patient, the use of 1 Cal corresponds to the use of 1 mL of water

17

Summary “maintenance fluids”

Fluid needs are linked to the metabolic rate.

Maintenance is approximately insensible plus urine losses.

Maintenance fluids of the “average” patient are approximately:

1st 10 kg: 100 cc / kg / day

2nd 10 kg: 50 cc / kg / day

the rest: 20 cc / kg / day

18

Increased INSENSIBLE Losses

Fever (each deg > 38): 12.5%Prematurity 100-300%Radiant warmer 50-100%Phototherapy 25-50%Increased activity 5-25%

Decreased INSENSIBLE Losses

Ventilation (humidified air) 25-40%Sedation 5-25%Decreased activity 5-25%Hypothermia 5-15%Enclosed Incubator 25-50%

Changes in the metabolic rate or the environment change insensible fluid loss

19

Common / “Community” lossesGastrointestinal: diarrhea, vomitingActivity: sweating, increased ventilation, heatBurns: (even sunburn!)

Uncommon / “Nosocomial” lossesDrainage (eg chest tube, NG tube, et cetera)BleedingPathological renal losses (eg salt wasting, diabetes)

These losses are universally hypo- or isotonic

Maintenance Fluid DOES NOTInclude Abnormal Losses

20

FluidNa

(mEq/L)K

(mEq/L)Cl

(mEq/L)Gastric 20–80 5–20 100–150Pancreatic 120–140 5–15 90–120Small bowel 100–140 5–15 90–130Bile 120–140 5–15 80–120Ileostomy 45–135 3–15 20–115Diarrhea 10–90 10–80 10–110Burns 140 5 110Sweat       Normal 10–30 3–10 10–35 Cystic fibrosis 50–130 5–25 50–110

Composition of Various Body Fluids

Harriet Lane Handbook

21

Na: 2-5 mEq / kg /dayK: 1-2 mEq / kg /day

There is a large variability in the intake of Na, and to a lesser extent K, by healthy people.

Renal ability to conserve or excrete Na is very large.

The ability to conserve or secrete K is also larger than the average variation in intake.

“Salt” Maintenance Requirements

22

23

An 18 month old boy presents to the ER with a history of vomiting and diarrhea for several days. He is lethargic, has poor skin turgor, dry mucus membranes, and has tachycardia. He took 5 ml oral fluid but vomited almost immediately. The next most appropriate step is to:

A. Give 20 ml/kg of D5 0.45% NS intravenously over 20-30 min

B. Give 5 ml/kg of D5 0.9% NS intravenously over 20-30 min

C. Give 20 ml/kg of 0.9% NS intravenously over 20-30 min

D. Give 10 ml/kg of 3% NS intravenously over 20-30 min

E. Await serum electrolytes before giving IV fluid

Give 20 ml/k

g of D

5 0.45...

Give 5 ml/k

g of D

5 0.9% N...

Give 20 ml/k

g of 0

.9% NS .

..

Give 10 ml/k

g of 3

% NS i..

.

Await seru

m electrolyt

es...

0% 0% 0%0%0%

6

24

A nearly 1 month old boy has been vomiting his feedings forcefully for 2 days. He is afebrile and has no diarrhea. He had 1 wet diaper in the last day. He appears dehydrated. He eagerly takes fluids but vomits (non-bilious) immediately and while he does so you note “waves” on his abdomen. What is the most likely set of labs?

Serum pH Serum Na Serum K Serum Cl

A. Low High Low Low

B. High Normal High Low

C. High Normal Low Low

D. Normal Low Low Low

E. High Low Low High

25

A nearly 1 month old boy has been vomiting his feedings forcefully for 2 days. He is afebrile and has no diarrhea. He had 1 wet diaper in the last day. He appears dehydrated. He eagerly takes fluids but vomits (non-bilious) immediately and while he does so you note “waves” on his abdomen. What is the most likely set of labs?

Serum pH Serum Na Serum K Serum Cl

A. Low High Low Low

B. High Normal High Low

C. High Normal Low Low

D. Normal Low Low Low

E. High Low Low High

26

Mild Moderate Severe

Weight Loss5% (infant)

2% (child/adult)10% (infant)

6% (child/adult)15% (infant)

9% (child/adult)

Sensorium NormalFussy

LethargicPoor

arousability

Urine Outputhrs w/o UOP

range

Slight decrease2-3 hours

0.5-1.5 cc/kg/hr

Notable decrease4-6 hours

<0.5 cc/kg/hr

Anuric6-12 hours

None

Signs & Symptoms of Dehydration I(fairly reliable)

Harriet Lane Handbook

27

Mild Moderate Severe

Skin turgor or quality

1+ decreasepale

2+ decrease“gray”

3+ decreasemottled

Mucus Membranes

Dry / “tacky” Drier “parched”

PulseSlightly

increasedIncreased

Very increased

Fontanelle Normal Intermediate Sunken

Eyes Normal Intermediate Sunken

Blood Pressure Normal About normal Low

Signs & Symptoms of Dehydration II(less reliable)

Harriet Lane Handbook

28

A 2 year-old presents with a 1 day history diarrhea and a 5% weight loss. Which of the following best represents the distribution of the fluid loss?

Extracellular Intracellular

A. 80% 20%

B. 60% 40%

C. 40% 60%

D. 20% 80%

E. None of the above

29

A 2 year-old presents with a 1 day history diarrhea and a 5% weight loss. Which of the following best represents the distribution of the fluid loss?

Extracellular Intracellular

A. 80% 20%

B. 60% 40%

C. 40% 60%

D. 20% 80%

E. None of the above

3 or more days: the correct answer would have been B. The ICF is relatively protected from volume loss.

Harriet Lane Handbook

30

A nearly 13 month old girl has had diarrhea for 5 days. She has few wet diapers. Her BP is 86/40, pulse is 135. She weighs 9 kg and you estimate she is 10% dehydrated based on clinical parameters. Disregarding Na losses from the ICF, which of the following estimates is best?

Total Deficit ECF loss ICF loss Na Loss

A. 900 mL 540 ml 360 ml 75 mEq

B. 1000 mL 800 ml 200 ml 110 mEq

C. 1000 mL 400 ml 600 ml 55 mEq

D. 1000 mL 600 ml 400 ml 85 mEq

E. 100 mL 80 mL 20 mL 10 mEq

31

A nearly 13 month old girl has had diarrhea for 5 days. She has few wet diapers. Her BP is 86/40, pulse is 135. She weighs 9 kg and you estimate she is 10% dehydrated based on clinical parameters. Disregarding Na losses from the ICF, which of the following estimates is best?

Total Deficit ECF loss ICF loss Na Loss

A. 900 mL 540 ml 360 ml 75 mEq

B. 1000 mL 800 ml 200 ml 110 mEq

C. 1000 mL 400 ml 600 ml 55 mEq

D. 1000 mL 600 ml 400 ml 85 mEq

E. 100 mL 80 mL 20 mL 10 mEq

32

A 13 month old child was seen for a checkup and weighed 10 kg. 10 days later in the ER with gastroenteritis she weighs 9 kg. 10% Dehydration.

A liter weighs 1 kg.

A pint’s a pound the world around.

33

A high school student and her friend have multiple episodes of vomiting and watery diarrhea after sharing lunch from a food cart at the park earlier in the day. Her bp is 95/45 and her pulse increases from 90 to 115 standing. She feels light-headed and has not urinated in the last 6 hours. Which is the most likely type of dehydration?

A. Isotonic

B. Hypotonic

C. Hypertonic

D. All are equally likely

34

A high school student and her friend have multiple episodes of vomiting and watery diarrhea after sharing lunch from a food cart at the park earlier in the day. Her bp is 95/45 and her pulse increases from 90 to 115 standing. She feels light-headed and has not urinated in the last 6 hours. Which is the most likely type of dehydration?

A. Isotonic

B. Hypotonic

C. Hypertonic

D. All are equally likely

35

A 14 year old girl is treated with a prolonged course of antibiotics for sinusitis. She develops profuse watery diarrhea that lasts several days. She had not been eating due to abdominal pain but had taken at least 2 liters of a yellow sports drink each day. In the ER, she still appears moderately dehydrated. You diagnose C. Dificile colitis. The most likely type of dehydration is:

A. Isotonic

B. Hypotonic

C. Hypertonic

D. All are equally likely

36

A 14 year old girl is treated with a prolonged course of antibiotics for sinusitis. She develops profuse watery diarrhea that lasts several days. She had not been eating due to abdominal pain but had taken at least 2 liters of a yellow sports drink each day. In the ER, she still appears moderately dehydrated. You diagnose C. Dificile colitis. The most likely type of dehydration is:

A. Isotonic

B. Hypotonic

C. Hypertonic

D. All are equally likely

37

A 14 year old boy with cerebral palsy and mental retardation develops fever to 40 °C. He is able to tolerate his usual liquid formula diet by gastric tube. You diagnose him with streptococcal pharyngitis but also note he has very dry mucus membranes and his skin feels thick. Which is the most likely set of lab findings?

Serum Na Serum Osm Urine Na Urine Osm

A. High High Low High

B. Low Low High High

C. High High High High

D. Low Normal High High

E. Normal Normal Low Low

38

A 14 year old boy with cerebral palsy and mental retardation develops fever to 40 °C. He is able to tolerate his usual liquid formula diet by gastric tube. You diagnose him with streptococcal pharyngitis but also note he has very dry mucus membranes and his skin feels thick. Which is the most likely set of lab findings?

Serum Na Serum Osm Urine Na Urine Osm

A. High High Low High

B. Low Low High High

C. High High High High

D. Low Normal High High

E. Normal Normal Low Low

39

Tonicity Plasma Na (mEq/L)

Incidence Example etiologies

Iso 130-150 60% diarrhea, vomiting

Hyper >150 25% A loss PLUS: no thirst or no tolerance for or no access to water

Hypo <130 15% Any loss PLUS water replacement in excess of solute replacement.

Worse if loss had some Na (CF, salt-wasting )

Tonicity Classification of Dehydration

40

41

A 10 year old boy has high fever and dehydration due to seasonal influenza. He has not urinated in over 24 hours. His serum creatinine is elevated from 0.7 to 1.6. Urine is taken to calculate fractional excretion of Na. Two days later he is rehydrated and has normal urine output and his creatinine is baseline. What best describes his diagnosis and most likely FENa on presentation?

A. Acute kidney injury – FENa 3%

B. Acute kidney injury – FENa 0.3%

C. Pre-renal azotemia – FENa 3%

D. Pre-renal azotemia – FENa 0.3%

0% 0%0%0%

6

42

Consider a child with sepsis and decreased urine output with the following labs:

SERUM: Na 124, K 4, Cl 94, Total CO2 12Creat 0.8 mg/dL, BUN 40, Glucose 70

URINE: specific gravity 1.030, trace protein, no blood or glucose, small ketones; urine Na 15, creat 40

43

FENa is a useful test when:•The urine output is low.•No current use of diuretics.

< 1% (0.01): pre-renal azotemia (“acute renal success”)> 2% (0.02): acute kidney injury (“acute renal failure”)

Exceptions: acute GN has low FENa, obstruction can vary

44

A 4 year-old girl with a ventriculoperitoneal shunt presents with a week of vague symptoms progressing toward listlessness and decreased speech, finally with a 5 minute seizure. The bulb of the shunt empties with pressure but is slow to refill. She does not appear dehydrated. The most likely set of laboratory findings is:

Serum NamEq/L

Urine NamEq/L

Serum OsmmOsm/kg

Urine OsmmOsm/kg

A 150 5 320 90

B 140 40 295 400

C 130 25 275 450

D 120 50 265 90

E 120 50 265 500

45

A 4 year-old girl with a ventriculoperitoneal shunt presents with a week of vague symptoms progressing toward listlessness and decreased speech, finally with a 5 minute seizure. The bulb of the shunt empties with pressure but is slow to refill. She does not appear dehydrated. The most likely set of laboratory findings is:

Serum NamEq/L

Urine NamEq/L

Serum OsmmOsm/kg

Urine OsmmOsm/kg

A 150 5 320 90

B 140 40 295 400

C 130 25 275 450

D 120 50 265 90

E 120 50 265 500

46

SIADH: Too Much ADH

Etiologies:• CNS disease (hydrocephalus, meningitis, etc)• Lung (pneumonia, RSV, etc)• Nausea or Pain• Cancer or Stem Cell transplantation• Drugs (SSRI’s)

Should exclude:•Thyroid, adrenal, cardiac, or renal disease•Volume deficits / dehydration

Hyponatremia, inappropriately high urine Osm (>100)Urine Na can be variable– usually “highish”

47

A 7 year-old girl presents for secondary enuresis. On review of systems she has significant polyuria, polydipsia, and severe daily headaches that awaken her in the morning. Urinalysis in your office is negative for glucose and ketones. The most likely set of laboratory findings is:

Serum NamEq/L

Urine NamEq/L

Serum OsmmOsm/kg

Urine OsmmOsm/kg

A 160 40 330 900

B 150 25 315 350

C 150 5 320 200

D 140 5 295 90

E 130 25 275 275

48

A 7 year-old girl presents for secondary enuresis. On review of systems she has significant polyuria, polydipsia, and severe daily headaches that awaken her in the morning. Urinalysis in your office is negative for glucose and ketones. The most likely set of laboratory findings is:

Serum NamEq/L

Urine NamEq/L

Serum OsmmOsm/kg

Urine OsmmOsm/kg

A 160 40 330 900

B 150 25 315 350

C 150 5 320 200

D 140 5 295 90

E 130 25 275 275

49

Diabetes Insipidus: Not Enough ADHOr ADH not Effective

Etiologies:• CNS disease (pituitary infiltration, damage)• Drugs (lithium)• Nephrogenic (V2 receptor or aquaporin defect)• Others more rare

With access to water, just polyuria, polydipsiaWithout access to water, hypernatremia, polyuria, polydipsiaHypernatremic dehydration

• Inappropriately dilute urine• Water deprivation test diagnostic but dangerous• Response to DDAVP diagnostic of central DI• Genetic testing for nephrogenic DI

50

An overweight 15 year old girl is admitted with polyuria and severe dehydration. Severe hyperglycemia of 800 mg/dl without ketoacidosis is discovered. Serum electrolytes are significant for Na of 140, K of 4.3, Cl of 98, CO2 of 19, BUN is 53, Creatinine is 1.6. Which of the following is NOT true?

A. Excessive 0.9% NS may exacerbate the situation.

B. Serum K can be expected to fall with rehydration

C. Serum NA can be expected to rise with rehydration

D. Hyperglycemia causes the lab equipment to malfunction and produce falsely low NA values

E. Dehydration is the result of osmotic diuresis Exc

essive

0.9% NS m

ay e...

Serum K ca

n be expecte

d ..

Serum N

A can be expecte

...

Hyperglyce

mia cause

s the...

Dehydrati

on is th

e resu

lt ..

0% 0% 0%0%0%

6

51

Acid / Base

Mr. Osborne, may I be excused? My brain is full.

52

A 6 month old girl born at term and with no apparent illnesses presents with failure to thrive. She is mildly tachypneic at rest. Lab evaluation is remarkable for serum Na 140, K 2.5, Chloride of 115, bicarbonate of 11 and creatinine of 0.3 mg/dL. Which of the following is most consistent with distal (type I) renal tubular acidosis (RTA)?

Urine pH

Urine Ca

Urine Citrate

Urine K

Urine Anion Gap (Na+ + K+) - Cl-

A 6.5 High Low High > 0 (positive)

B 6.5 Low Low High > 0 (positive)

C < 5.5 High Low High < 0 (negative)

D > 7 High Low High > 0 (positive)

E > 7 Low High Low < 0 (negative)

** CORRECTION

53

A 6 month old girl born at term and with no apparent illnesses presents with failure to thrive. She is mildly tachypneic at rest. Lab evaluation is remarkable for serum Na 140, K 2.5, Chloride of 115, bicarbonate of 11 and creatinine of 0.3 mg/dL. Which of the following is most consistent with distal (type I) renal tubular acidosis (RTA)?

Urine pH

Urine Ca

Urine Citrate

Urine K

Urine Anion Gap (Na+ + K+) - Cl-

A 6.5 High Low High > 0 (positive)

B 6.5 Low Low High > 0 (positive)

C < 5.5 High Low High < 0 (negative)

D > 7 High Low High > 0 (positive)

E > 7 Low High Low < 0 (negative)

54

Renal Tubular Acidosis

Associated with growth failureLow anion gap metabolic acidosisMay be compensated by pulmonary hyperventilationUrine anion gap should be positive: (Na+ + K+) > Cl-

Clinical pearls:• Confirm metabolic acidosis with a VBG• Distal RTA (type I) is most common• Types I and II have hypokalemia• Type IV has hyperkalemia (aldosterone defect)• Can be treated with bicitra with varying success

55

Renal Tubular Acidosis: Urine Anion Gap

Na+

+ K+

__– Cl-____ Anion Gap

What is NOT measured is ammonium

(NH4+)

Carmody, PREP 2011

Na++K+ < Cl-

UAG NegativeNon-renal acidosis

Na++K+ > Cl-

UAG PositiveRTA

56

Renal Tubular Acidosis: Distal vs Proximal

Distal (type 1)•Commonly associated with hypercalcURIA, stone risk•Late nephron defect, urine pH “always” > 5.5•Low urine citrate•Distal RTA (type I) can associate with deafness

Proximal (type 2)•More rare•Often associated with Renal Fanconi Syndrome•Lower threshold of bicarbonate reabsorption•Urine pH depends on plasma bicarbonate, may be < 5.5

57

A Normal anion gap metabolic acidosis

B Low anion gap metabolic acidosis

C High anion gap metabolic acidosis

D High anion gap respiratory alkalosis

E None of the above

An 8 year-old with type 1 diabetes mellitus is admitted to the ICU with pneumonia. His blood sugar is 450 mg/dL, serum Na is 133, K is 5.1, Cl 95, HCO3

- 8. The most likely acid-base disturbance is:

58

Don’t forget– we ASSUMED the pH was low because metabolic acidosis is so likely. We really need a blood gas to know for sure!

A Normal anion gap metabolic acidosis

B Low anion gap metabolic acidosis

C High anion gap metabolic acidosis

D High anion gap respiratory alkalosis

E None of the above

An 8 year-old with type 1 diabetes mellitus is admitted to the ICU with pneumonia. His blood sugar is 450 mg/dL, serum Na is 133, K is 5.1, Cl 95, HCO3

- 8. The most likely acid-base disturbance is:

59

High Anion Gap Metabolic Acidosis:

M: methanol (and metabolic diseases)

U: uremia

D: diabetes (ketoacids), d-lactic acidosis

P: (paraldehyde); propylene glycol

I: Isoniazid, Iron

L: Lactate

E: Ethanol, Ethylene glycol

S: Salicylates

60

A 3 day old male is referred to the ER by his pediatrician because he seems mildly lethargic. Electrolytes are Na 140, K 5.6, Cl 105, HCO3 12. He is afebrile, has BP 84/40 and a rr of 52. A blood ammonia level is markedly elevated. The MOST likely arterial blood gas result is:

pH pCO2 paO2 BE

A 7.53 15 134 9

B 7.25 55 81 -3

C 7.21 31 106 -14

D 7.48 52 85 13

E None of the above

61

A 3 day old male is referred to the ER by his pediatrician because he seems mildly lethargic. Electrolytes are Na 140, K 5.6, Cl 105, HCO3 12. He is afebrile, has BP 84/40 and a rr of 52. A blood ammonia level is markedly elevated. The MOST likely arterial blood gas result is:

pH pCO2 paO2 BE Interpretation

A 7.53 15 134 9 R. Alkalosis

B 7.25 55 81 -3 R. Acidosis

C 7.21 31 106 -14 M. Acidosis

D 7.48 52 85 13 M. Alkalosis

E None of the above

62

A 10 year old girl with ALL and neutropenia after chemotherapy develops shock. She has stable ventilatory status but is mildly tachypneic. Electrolytes and an arterial blood gas is obtained while she is provided isotonic fluid boluses and dopamine infusion is prepared. The most likely results of the ABG and plasma bicarbonate are:

pH HCO3- pCO2 paO2

A 7.53 12 15 134

B 7.21 16 40 100

C 7.48 37 52 85

D 7.25 23 55 81

E None of the above

63

A 10 year old girl with ALL and neutropenia after chemotherapy develops shock. She has stable ventilatory status but is mildly tachypneic. Electrolytes and an arterial blood gas is obtained while she is provided isotonic fluid boluses and dopamine infusion is prepared. The most likely results of the ABG and plasma bicarbonate are:

pH HCO3- pCO2 paO2 Interpretation

A 7.53 12 15 134 R. Alkalosis

B 7.21 16 40 100 M. Acidosis

C 7.48 37 52 85 M. Alkalosis

D 7.25 23 55 81 R. Acidosis

E None of the above

64

A 10 year old with dilated cardiomyopathy is admitted with pulmonary edema, intubated, and given 72 hours of continuous IV furosemide. The laboratory results return:

What is the best interpretation of these results?

pH pCO2 HCO3- BE paO2

7.43 45 12 -4 85

A Metabolic alkalosis due to diuretics

B Respiratory alkalosis due to hyperventilation

C Metabolic acidosis due to heart failure

D Respiratory acidosis due to pulmonary edema

E None of the above / Lab Error

65

A 10 year old with dilated cardiomyopathy is admitted with pulmonary edema, intubated, and given 72 hours of continuous IV furosemide. The laboratory results return:

What is the best interpretation of these results?

pH pCO2 HCO3- BE paO2

7.43 45 12 -4 85

A Metabolic alkalosis due to diuretics

B Respiratory alkalosis due to hyperventilation

C Metabolic acidosis due to heart failure

D Respiratory acidosis due to pulmonary edema

E None of the above / Lab Error

66

A 6 month old boy develops diarrhea for 4 days. He appears dehydrated and is given a bolus of 0.9% NS and promptly produces a generous wet diaper. Electrolytes are obtained with difficulty during the blood draw and return the following values: Na 143, K 7.3, Cl 109, CO2 14, Ca is 10.1 mg/dl. The next step in management is

A Repeat the laboratory tests in 24 hours

B Administer intravenous Calcium gluconate

C Administer intravenous sodium bicarbonate

D Begin intravenous D5 0.45% NS with 20 mEq KCl per liter at 1.5 times maintenance rate

E None of the above

67

A 6 month old boy develops diarrhea for 4 days. He appears dehydrated and is given a bolus of 0.9% NS and promptly produces a generous wet diaper. Electrolytes are obtained with difficulty during the blood draw and return the following values: Na 143, K 7.3, Cl 109, CO2 14, Ca is 10.1 mg/dl. The next step in management is

A Repeat the laboratory tests in 24 hours

B Administer intravenous Calcium gluconate

C Administer intravenous sodium bicarbonate

D Begin intravenous D5 ½ 0.9% NS with 20 mEq KCl per liter at 1.5 times maintenance rate

E None of the above

68

A 9 year old boy is chronically treated with oral furosemide for vascular congestion related to dilated cardiomyopathy. All of the following electrolyte disturbances are likely EXCEPT:

A Hypokalemia

B Hypophosphatemia

C Hypocalcemia

D Hyponatremia

E Hypomagnesemia

69

A 9 year old boy is chronically treated with oral furosemide for vascular congestion related to dilated cardiomyopathy. All of the following electrolyte disturbances are likely EXCEPT:

A Hypokalemia

B Hypophosphatemia

C Hypocalcemia

D Hyponatremia

E Hypomagnesemia

70

Hyperkalemia can be induced by all of the following medications EXCEPT:

A Intravenous terbutaline

B Epinephrine

C Angiotensin converting enzyme inhibitor

D Hydrochlorthiazide (HCTZ)

E Spironolactone

71

Hyperkalemia can be induced by all of the following medications EXCEPT:

A Intravenous terbutaline

B Epinephrine

C Angiotensin converting enzyme inhibitor

D Hydrochlorthiazide (HCTZ)

E Spironolactone

72

UTI’s and So on…

73

An otherwise healthy, well-grown 4 year-old girl has had 3 febrile UTIs, the first at age 3 years. She has been taking TMP/SMX since the 2nd UTI. Review of systems reveals constipation. She has occasional enuresis but no frequency or dysuria. Renal sonography and voiding cystourethrogram (VCUG) are normal. Which of the following is likely to be helpful in her evaluation and treatment?

A Renal scintigraphy

B Evaluation for immunodeficiency

C Increase daily fluid intake to 2 – 2.5 liters/day

D Prescribe stool softener & a regular bowel routine

E Switch prophylaxis to nitrofurantoin

74

An otherwise healthy, well-grown 4 year-old girl has had 3 febrile UTIs, the first at age 3 years. She has been taking TMP/SMX since the 2nd UTI. Review of systems reveals constipation. She has occasional enuresis but no frequency or dysuria. Renal sonography and voiding cystourethrogram (VCUG) are normal. Which of the following is likely to be helpful in her evaluation and treatment?

A Renal scintigraphy

B Evaluation for immunodeficiency

C Increase daily fluid intake to 2 – 2.5 liters/day

D Prescribe stool softener & a regular bowel routine

E Switch prophylaxis to nitrofurantoin

75

A 3 month old male has a febrile UTI with E. Coli. His renal ultrasound is negative. The best test to evaluate for vesicoureteral reflux (VUR) is:

A 99Tc DTPA renal scintigraphy

B 99Tc DMSA renal scintigraphy

C Voiding cystourethrogram

D Urodynamics study

E Magnetic resonance (MR) urogram

76

A 3 month old male has a febrile UTI with E. Coli. His renal ultrasound is negative. The best test to evaluate for vesicoureteral reflux (VUR) is:

A 99Tc DTPA renal scintigraphy

B 99Tc DMSA renal scintigraphy

C Voiding cystourethrogram

D Urodynamics study

E Magnetic resonance (MR) urogram

77

All of the following statements about UTI are correct EXCEPT:

A Under the age of 1 year, the risk of UTI in females is greater than in males

B Circumcision of boys does not affect the risk of UTI

C The prevalence of UTI in febrile infants under 3 months of age and without an obvious source on clinical examination is 5-10%

D The incidence of UTI in patients with abnormal urinary tract anatomy is greater than in those with normal urinary tract anatomy

E There is controversy whether a 1st UTI requires evaluation if a prenatal sonogram was normal.

78

All of the following statements about UTI are correct EXCEPT:

A Under the age of 1 year, the risk of UTI in females is greater than in males

B Circumcision of boys does not affect the risk of UTI

C The prevalence of UTI in febrile infants under 3 months of age and without an obvious source on clinical examination is 5-10%

D The incidence of UTI in patients with abnormal urinary tract anatomy is greater than in those with normal urinary tract anatomy

E There is controversy whether a 1st UTI requires evaluation if a prenatal sonogram was normal.

79

An 8 month old male is found to have grade II VUR on the right and grade IV VUR on the left with mild hydronephrosis. Which of the following are immediately appropriate:

A Daily antibiotic prophylaxis

B Antibiotic prophylaxis and repeat VCUG in 6 months

C Antibiotic prophylaxis and schedule correction of VUR by bilateral endoscopic injection of gel in the bladder wall under the ureteral orifice

D Antibiotic prophylaxis and left ureteral reimplant

E None of the above

80

An 8 month old male is found to have grade II VUR on the right and grade IV VUR on the left with mild hydronephrosis. Which of the following are immediately appropriate:

A Daily antibiotic prophylaxis

B Antibiotic prophylaxis and repeat VCUG in 6 months

C Antibiotic prophylaxis and schedule correction of VUR by bilateral endoscopic injection of gel in the bladder wall under the ureteral orifice

D Antibiotic prophylaxis and left ureteral reimplant

E None of the above

81

Besides fever, signs and symptoms of UTI in infants include:

A Irritability

B Diarrhea

C Difficulty feeding

D Jaundice

E Any of the above

82

Besides fever, signs and symptoms of UTI in infants include:

A Irritability

B Diarrhea

C Difficulty feeding

D Jaundice

E Any of the above

83

An 8 year old boy in the 3rd grade develops secondary nocturnal enuresis. On review of systems he has constipation. When he was a newborn you had ordered a spinal ultrasound and x-ray after noting a sacral dimple, and both were normal. Urinalysis is negative for leukocyte esterase and nitrates. The next most appropriate steps are:

A Renal and bladder ultrasound

B Spine MRI and referral to pediatric neurosurgery

C Prescribe stool softener & a regular bowel routine

D Referral to pediatric urology

E Reduce evening fluids & use a bedtime wetting alarm

84

An 8 year old boy in the 3rd grade develops secondary nocturnal enuresis. On review of systems he has constipation. When he was a newborn you had ordered a spinal ultrasound and x-ray after noting a sacral dimple, and both were normal. Urinalysis is negative for leukocyte esterase and nitrates. The next most appropriate steps are:

A Renal and bladder ultrasound

B Spine MRI and referral to pediatric neurosurgery

C Prescribe stool softener & a regular bowel routine

D Referral to pediatric urology

E Reduce evening fluids & use a bedtime wetting alarm

85

Nephrology

86

A 3 year-old boy is referred to pediatric nephrology for sudden onset of edema and 4+ proteinuria. True statements about the nephrotic syndrome in this child include:

A The majority of children will respond to corticosteroid treatment within 1 week

B IV infusion of 25% albumin and furosemide will decrease recovery time

C Progression to renal failure is likely

D Steroid response is predictive of renal histology

E A family history of nephrotic syndrome is common

87

A 3 year-old boy is referred to pediatric nephrology for sudden onset of edema and 4+ proteinuria. True statements about the nephrotic syndrome in this child include:

A The majority of children will respond to corticosteroid treatment within 1 week

B IV infusion of 25% albumin and furosemide will decrease recovery time

C Progression to renal failure is likely

D Steroid response is predictive of renal histology

E A family history of nephrotic syndrome is common

88

A 14 year-old overweight girl has proteinuria 100 mg/dL on two separate occasions, first noted during a screening examination for summer camp. The remainder of the urinalysis is normal and the blood pressure is normal. The most appropriate next step in management is:

A Request a hemoglobin A1C

B Renal and bladder ultrasonography

C Request a urine culture

D Request a first morning urine protein and creatinine

E Request a 24 hour urine collection for protein

89

A 14 year-old overweight girl has proteinuria 100 mg/dL on two separate occasions, first noted during a screening examination for summer camp. The remainder of the urinalysis is normal and the blood pressure is normal. The most appropriate next step in management is:

A Request a hemoglobin A1C

B Renal and bladder ultrasonography

C Request a urine culture

D Request a first morning urine protein and creatinine

E Request a 24 hour urine collection for protein

90

A 14 year old boy has microscopic hematuria on a urinalysis done for a school form. Family history is significant for his mother having microscopic hematuria since childhood. A maternal uncle required dialysis. Which of the following is true of this boy’s condition?

A It is associated with conductive hearing loss

B It is associated with retinal abnormalities

C Immunoglobulin A levels are elevated in 50% of cases

D Female carriers are at risk of kidney failure

E Skin biopsy may reveal leukocytoclastic vasculitis

91

A 14 year old boy has microscopic hematuria on a urinalysis done for a school form. Family history is significant for his mother having microscopic hematuria since childhood. A maternal uncle required dialysis. Which of the following is true of this boy’s condition?

A It is associated with conductive hearing loss

B It is associated with retinal abnormalities

C Immunoglobulin A levels are elevated in 50% of cases

D Female carriers are at risk of kidney failure

E Skin biopsy may reveal leukocytoclastic vasculitis

92

A 14 year old boy has microscopic hematuria on a urinalysis done for a school form. Family history is significant for his father and a paternal grandparent having long-standing microscopic hematuria. There is no family history of kidney failure. There is no proteinuria. Blood pressure, urine calcium, and renal/bladder sonography is normal. Which of the following is true?

A There is an elevated risk of kidney stones

B Renal biopsy is indicated

C The glomerular basement membrane often appears thick by electron microscopic examination.

D Female carriers are at risk of kidney failure

E None of the above

93

A 14 year old boy has microscopic hematuria on a urinalysis done for a school form. Family history is significant for his father and a paternal grandparent having long-standing microscopic hematuria. There is no family history of kidney failure. There is no proteinuria. Blood pressure, urine calcium, and renal/bladder sonography is normal. Which of the following is true?

A There is an elevated risk of kidney stones

B Renal biopsy is indicated

C The glomerular basement membrane often appears thick by electron microscopic examination.

D Female carriers are at risk of kidney failure

E None of the above

94

A 3 day old male infant has been is brought to the ER for blood in the diaper, which the family produces. The diaper has multiple brick-red discolorations in the front. There is no significant perinatal history. Exam finds a vigorous infant in no distress with normal blood pressure. Bagged urinalysis is negative for blood by dipstick and by microscopy. The most likely cause of these findings is:

A Hemoglobinuria

B Sickle cell trait

C Calcium oxalate crystals

D Uric acid crystals

E Porphyria

95

A 3 day old male infant has been is brought to the ER for blood in the diaper, which the family produces. The diaper has multiple brick-red discolorations in the front. There is no significant perinatal history. Exam finds a vigorous infant in no distress with normal blood pressure. Bagged urinalysis is negative for blood by dipstick and by microscopy. The most likely cause of these findings is:

A Hemoglobinuria

B Sickle cell trait

C Calcium oxalate crystals

D Uric acid crystals

E Porphyria

96

HematuriaRed Urine Hematuria

See Harriet Lane list– favorites for the boards!(eg beets, blackberries, urates, rifampin)

In reality, red urine that is not blood is not commonly encountered in practice, except maybe red diaper urates.

Important uncommon causes:hemoglobinuriamyoglobinuria

97

A 16 year old boy develops sharp flank pain and gross hematuria. Sonography shows multiple large “soap bubble” cysts in each kidney. The mother reports that her mother, who lived in a developing country, suffered from episodes of painful blood in the urine and died with a kidney disease in her 40’s. Which of the following is true?

A The disease is associated with hearing loss

B The disease is associated with intracranial aneurysms

C An older brother, age 20, has a normal sonogram and therefore does not carry the gene

D Both parents are carriers of the gene

E This disease is found in about 1 in 5000 people

98

A The disease is associated with hearing loss

B The disease is associated with intracranial aneurysms

C An older brother, age 20, has a normal sonogram and therefore does not carry the gene

D Both parents are carriers of the gene

E This disease is found in about 1 in 5000 people

A 16 year old boy develops sharp flank pain and gross hematuria. Sonography shows multiple large “soap bubble” cysts in each kidney. The mother reports that her mother, who lived in a developing country, suffered from episodes of painful blood in the urine and died with a kidney disease in her 40’s. Which of the following is true?

99

Polycystic Kidney Disease

Autosomal Dominant PKD (ADPKD)• More commonly affects adults• Larger cysts, liver cysts• Intracranial aneurysms• Mitral valve prolapse, aortic root dilitation• Common: affects about 1:1000

Autosomal Recessive PKD (ARPKD)• More commonly affects infants• Smaller cysts, liver fibrosis (ductal plate malformation)• May need liver and/or kidney transplant• Rare: affects about 1 in 20,000

100

2 days following a fall trip to a farm and apple cider press in the country, a 3 year old boy develops bloody diarrhea which his parents manage at home with fluids. The next week, the is brought to the ER lethargic and pale. He has not urinated in over 8 hours. Lab testing finds WBC of 26,000, hemoglobin of 9.8 g/dL, platelets 65,000, serum creatinine of 1 mg/dL, BUN 54 mg/dL. All of the following statements about this condition are true EXCEPT:

A It is precipitated by infection with enteric bacteria producing shiga toxin such as E. Coli O157:H7

B It is preventable by early treatment with antibiotics

C End stage renal failure is uncommon

D Recurrence is atypical

E Hypertension is common and may be severe

101

2 days following a fall trip to a farm and apple cider press in the country, a 3 year old boy develops bloody diarrhea which his parents manage at home with fluids. The next week, the is brought to the ER lethargic and pale. He has not urinated in over 8 hours. Lab testing finds WBC of 26,000, hemoglobin of 9.8 g/dL, platelets 65,000, serum creatinine of 1 mg/dL, BUN 54 mg/dL. All of the following statements about this condition are true EXCEPT:

A It is precipitated by infection with enteric bacteria producing shiga toxin such as E. Coli O157:H7

B It is preventable by early treatment with antibiotics

C End stage renal failure is uncommon

D Recurrence is atypical

E Hypertension is common and may be severe

102

A 4 month old girl is brought to the ER lethargic and pale. She has not urinated in over 8 hours. Lab testing finds WBC of 26,000, hemoglobin of 8.8 g/dL, platelets 56,000, serum creatinine of 1 mg/dL, BUN 54 mg/dL. The blood smear shows schistocytes and helmet cells. True statements about this case include all of the following EXCEPT:

A Defective complement system regulation is likely

B Hypertension is common and may be severe

C End stage renal failure is common

D Recurrence is common

E Treatment is symptomatic

103

A 4 month old girl is brought to the ER lethargic and pale. She has not urinated in over 8 hours. Lab testing finds WBC of 26,000, hemoglobin of 8.8 g/dL, platelets 56,000, serum creatinine of 1 mg/dL, BUN 54 mg/dL. The blood smear shows schistocytes and helmet cells. True statements about this case include all of the following EXCEPT:

A Defective complement system regulation is likely

B Hypertension is common and may be severe

C End stage renal failure is common

D Recurrence is common

E Treatment is symptomatic

104

A 6 year-old girl develops tea-colored urine. Urine dip finds 4+ blood and 3+ protein. There is mild edema present and the blood pressure is 114/74. Review of systems is negative. Her twin brother currently has fever and a sore throat. Which of the following statements is CORRECT?

A. Complement C3 & C4 may remain low for 4-6 weeks

B. The brother can be protected from the same condition by prompt antibiotic treatment

C. The is a high risk of rheumatic heart disease also

D. Rapid progression and need for dialysis is uncommon and requires renal bipsy

E. Hypertension is uncommon and requires renal biopsy

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C4 ma...

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The is a high ri

sk of r

he...

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105

A 14 year old boy is uncharacteristically tired in the afternoons and appears somewhat pale to his mother. Laboratory findings consistent with chronic kidney disease with decreased glomerular filtration rate (GFR) include:MCV = mean corpuscular volumePTH = parathyroid hormone

MCV Na Ca PTH HCO3-

A Low Normal High High Low

B Normal Low Low Low High

C Normal Normal Low High Low

D High High Normal Low Low

E Low Normal Low Normal Low

106

A 14 year old boy is uncharacteristically tired in the afternoons and appears somewhat pale to his mother. Laboratory findings consistent with chronic kidney disease with decreased glomerular filtration rate (GFR) include:MCV = mean corpuscular volumePTH = parathyroid hormone

MCV Na Ca PTH HCO3-

A Low Normal High High Low

B Normal Low Low Low High

C Normal Normal Low High Low

D High High Normal Low Low

E Low Normal Low Normal Low

107

A 7 year-old boy with a history of posterior urethral valves and stage 3 CKD has short stature. All of the following factors commonly contribute to short stature in children with CKD EXCEPT:

IGF: insulin-like growth factor

A Growth hormone deficiency

B Resistance to growth hormone

C Decreased bioavailability of IGF-1 due to increased IGF binding proteins

D Vitamin D deficiency and renal osteodystrophy

E Nutritional disturbances

108

A 7 year-old boy with a history of posterior urethral valves and stage 3 CKD has short stature. All of the following factors commonly contribute to short stature in children with CKD EXCEPT:

IGF: insulin-like growth factor

A Growth hormone deficiency

B Resistance to growth hormone

C Decreased bioavailability of IGF-1 due to increased IGF binding proteins

D Vitamin D deficiency and renal osteodystrophy

E Nutritional disturbances

109

A newborn has a sonogram due to an abnormal prenatal sonogram. The left kidney is bit large but otherwise normal. The right kidney has multiple cystic areas and abnormal cortex. The right side shows no uptake on nuclear renal scan. All of the following statements are correct EXCEPT:

A Vesicoureteral reflux is a common finding

B Genetic testing is not likely to be useful

C The left kidney will eventually develop cysts and fail

D There is an increased risk of hypertension

E ALL of the above are correct

110

A newborn has a sonogram due to an abnormal prenatal sonogram. The left kidney is bit large but otherwise normal. The right kidney has multiple cystic areas and abnormal cortex. The right side shows no uptake on nuclear renal scan. All of the following statements are correct EXCEPT:

A Vesicoureteral reflux is a common finding

B Genetic testing is not likely to be useful

C The left kidney will eventually develop cysts and fail

D There is an increased risk of hypertension

E ALL of the above are correct

111

The parents of a 15 year-old followed in the renal clinic for advancing kidney disease ask your advice about what will happen as his kidneys fail. All of the following are true about End Stage Renal Disease (ESRD) EXCEPT:

A A kidney from a live donor is usually better than from a deceased donor.

B Hemodialysis does not replace all of the function of the kidneys

C Peritoneal dialysis is usually done at home

D Nutritional restrictions frequently include potassium, phosphorus, and sodium.

E All of the above are true

112

The parents of a 15 year-old followed in the renal clinic for advancing kidney disease ask your advice about what will happen as his kidneys fail. All of the following are true about End Stage Renal Disease (ESRD) EXCEPT:

A A kidney from a live donor is usually better than from a deceased donor.

B Hemodialysis does not replace all of the function of the kidneys

C Peritoneal dialysis is usually done at home

D Nutritional restrictions frequently include potassium, phosphorus, and sodium.

E All of the above are true

113

Blood Pressure andHypertension

114

A 9 year-old girl with no symptoms has BP 145-165 / 90-100 discovered on a routine physical and confirmed several times. The remainder of her examination is normal. True statements about this case include:

A Two additional measurements of BP are required to make the diagnosis of hypertension

B The most likely diagnosis is essential hypertension

C Best initial treatment is intravenous nicardipine infusion to lower the BP to normal

D Normal renal ultrasonography can rule out renal and renovascular causes of hypertension.

E The elevated blood pressure is likely long-standing

115

A 9 year-old girl with no symptoms has BP 145-165 / 90-100 discovered on a routine physical and confirmed several times. The remainder of her examination is normal. True statements about this case include:

A Two additional measurements of BP are required to make the diagnosis of hypertension

B The most likely diagnosis is essential hypertension

C Best initial treatment is intravenous nicardipine infusion to lower the BP to normal

D Normal renal ultrasonography can rule out renal and renovascular causes of hypertension.

E The elevated blood pressure is likely long-standing

116

All of the following statements about normal blood pressure in children are true EXCEPT:

A Normal BP increases with age during childhood

B Boys normally have higher BP than girls

C Normal BP is higher in taller children

D Normal BP is higher in overweight and obese children

E ALL of the above are true statements

117

All of the following statements about normal blood pressure in children are true EXCEPT:

A Normal BP increases with age during childhood

B Boys normally have higher BP than girls

C Normal BP is higher in taller children

D Normal BP is higher in overweight and obese children

E ALL of the above are true statements

Increased BP with height is physiologic and normal.Increased BP with obesity is pathophysiological and abnormal.

118

Blood Pressure Tables

119

Blood Pressure Tables

PEDIATRICS Vol. 114 No. 2 August 2004, pp. 555-576

120

4th Report BP Designations

Percentile Designation (Diastolic or Systolic)

< 90th Normal

90th to 95th “pre-hypertension”

95th to 99th + 5 Hypertension (“stage 1”)

Over 99th + 5 Severe hypertension (“stage 2”)

121

A 9 year-old girl with asymptomatic stage 2 HTN is evaluated first by renal sonography then by magnetic resonance arteriography. A long right-sided renal arterial narrowing with high velocities is suspicious for renal artery stenosis. She was not in the NICU after birth and never had central venous nor arterial access. The MOST likely etiology of this disease is:

A Tuberous sclerosis

B Neurofibromatosis

C Williams Syndrome

D Bartter Syndrome

E Fibromuscular dysplasia

122

A 9 year-old girl with asymptomatic stage 2 HTN is evaluated first by renal sonography then by magnetic resonance arteriography. A long right-sided renal arterial narrowing with high velocities is suspicious for renal artery stenosis. She was not in the NICU after birth and never had central venous nor arterial access. The MOST likely etiology of this disease is:

A Tuberous sclerosis

B Neurofibromatosis

C Williams Syndrome

D Bartter Syndrome

E Fibromuscular dysplasia

123

A 13 year old girl with a BMI in the 96th percentile is referred for stage 1 HTN. Initial management should include all of the following EXCEPT:

A Therapeutic lifestyle changes

B Evaluation of lipid levels

C Urinalysis

D Thorough review of possible diet supplements, over-the-counter medications, caffeine intake, and illicit drug use

E Renal angiography

124

A 13 year old girl with a BMI in the 96th percentile is referred for stage 1 HTN. Initial management should include all of the following EXCEPT:

A Therapeutic lifestyle changes

B Evaluation of lipid levels

C Urinalysis

D Thorough review of possible diet supplements, over-the-counter medications, caffeine intake, and illicit drug use

E Renal angiography

Just making a point here– obesity-related HTN is common and frequently responds to diet and exercise (TLC). Don’t forget these other items– all are fair game for questions.

125

Keep Studying and Good Luck!