fluid and electrolyte emergencies in critically ill children ahmed khamis bamaga mbbs

Fluid and Electrolyte Emergencies in Critically

Ill Children

Fluid and Electrolyte Emergencies in Critically

Ill Children

Ahmed Khamis BamagaMBBS

ObjectivesObjectives

At the end of this presentation learners will be able to:

• 1) Recognize common fluid and electrolyte disorders in critically ill children

• 2) List a diagnostic strategy for these disorders

• 3) Apply appropriate management principles

Case Study #1Case Study #1

• HPI:• A 3 month-old is in the PICU for shock following a two day

history of fever and irritability. Blood and CSF cultures are positive for Streptococcus pneumoniae.

• Hospital course: • Decreasing urine output (< 0.5 ml/kg/hr) over the last 24

hours.


What is your differential diagnosis?

What diagnostic studies would you order?

Case Study #1

Differential diagnosisCase Study #1

Differential diagnosis

Oliguria

1) Pre-Renal (decreased effective renal blood flow)Diminished intravascular volume, cardiac dysfunction,

vasodilitation

2) Post-RenalOutlet obstruction (intrinsic vs. extrinsic), foley catheter occlusion

3) RenalAcute tubular necrosis, acute renal failure, SIADH, ...

Case Study #1

Laboratory studiesCase Study #1

Laboratory studies

Serum studiesSodium 126 mEq/L BUN 4 mg/dLChloride 98 mEq/L Creatinine 0.4 mg/dLPotassium 3.7 mEq/L Glucose 129 mg/dLBicarbonate 25 mEq/L Osmolality 260 mosmol/kg

Urine studiesSpecific gravity 1.025 Sodium 58 mEq/LOsmolality 645 mosmol/kg FeNa 2.4%

What are the primary abnormalities?

Case Study #1


Laboratory studies

Major abnormalities

1) Hyponatremia

2) Oliguria (inappropriately concentrated urine)

What is the most likely explanation for these findings?

Case Study #1 Syndrome of Inappropriate Antidiuretic

Hormone (SIADH)

Case Study #1 Syndrome of Inappropriate Antidiuretic

Hormone (SIADH)

• Variable etiology• Trauma• Infection• Psychosis• Malignancy• Medications• Diabetic ketoacidosis• CNS disorders• Positive pressure ventilation• “Stress”

Case Study #1 SIADH

Case Study #1 SIADH

• Manifestations• By definition, “inappropriate” implies having excluded

normal physiologic reasons for release of ADH:• 1) In response to hypertonicity.• 2) In response to life threatening hypotension.

• Hyponatremia• Oliguria• Concentrated urine

• elevated urine specific gravity• “inappropriately” high urine osmolality in face of hyponatremia

• Normal to high urine sodium excretion

Case Study #1 SIADH

Case Study #1 SIADH

• Diagnosis• Critical level of suspicion.• Demonstration of inappropriately concentrated urine in

face of hyponatremia urine osmolality, SG, urine sodium excretion ( FeNa)

• Be certain to exclude normal physiologic release of ADH Frequently secondary to decreased perfusion Serum sodium, urine osmolality, urine sodium

excretion (low FeNa) consistent with dehydration or diminished renal blood flow. Look at patient more closely !!

Case Study #1 SIADH

Case Study #1 SIADH

• Treatment

• Fluid restriction.• 50-75% of maintenance requirements, be certain to

include oral intake.

• Daily weights.

Case Study #1

The saga continues….Case Study #1

The saga continues….

Hospital course:Four hours after beginning fluid restriction, you are called

because the patient is having a generalized seizure. There is no response to two doses of IV lorazepam (Ativan®) and a loading dose of fosphenytoin (Cerebyx®)

What is the most likely explanation?

Case Study #1

The saga continuesCase Study #1

The saga continues

Seizure

1) Worsening hyponatremia2) Intracranial event3) Meningitis4) Other electrolyte disturbance5) Medication6) Hypertension


Case Study #1

The saga continuesCase Study #1

The saga continues

Stat labs:Sodium 117 mEq/L

What would you do now?

Case Study #1 Hyponatremic seizure

Case Study #1 Hyponatremic seizure

• Treatment • Hypertonic saline (3% NaCl) infusion

• To correct sodium to 125 mEq/L, the deficit is equal to (0.6)(weight[kg])(125- measured sodium) (0.6)(8)(125-117) = 38.4 mEq

• Because patient is symptomatic with seizures, immediately increase serum sodium by 5 mEq/L

mEq sodium = (0.6)(8 kg)(5) = 24 mEq

• 3% NaCl = 0.5 mEq/L, therefore 24 mEq bolus = 48 mls, followed by slow infusion of remaining 14.4 mEq (29 mls) over next several hours


HPI:A 5 month-old girl presents with a one day history of irritability

and fever. Mother reports three days of “bad” vomiting and diarrhea.

Home meds:Acetaminophen and ibuprofen for fever

PE: BP 70/40, HR 200, R 60, T38.3 C. Irritable, sunken eyes and

fontanelle, skin feels like Pillsbury Dough Boy


No one can obtain IV access after 15 minutes, what would you do now?


Place intraosseous lineBolus 40 ml/kg of isotonic salineReassessment (HR 170, RR 40, BP 75/40)

Serum studiesSodium 164 mEq/L BUN 75 mg/dLChloride 139 mEq/L Creatinine 3.1 mg/dLPotassium 5.5 mEq/L Glucose 101 mg/dLBicarbonate 12 mEq/LpH 7.07 pCO2 11

pO2 121 HCO3 8


What is the most likely explanation of this patients acidosis?

Case Study #2

Metabolic acidosis and the anion gap

Case Study #2


Anion GapSodium - (chloride + bicarbonate)

Normal 12 +/- 2 meq/L

Elevated anion gap consistent with excess acidNormal anion gap consistent with excess loss of base

164 - (139 + 12) = 13

1. Normal gap 2. Increased gap

1. Renal “HCO3” losses

2. GI “HCO3” losses

Proximal RTA Distal RTA Diarrhea

1. Acid prod 2. Acid elimination

LactateDKAKetosisToxins Alcohols Salicylates Iron

Renal disease

Case Study #2


Case Study #2



• HPI:• A five year old (18 kg) boy was involved in a a motor vehicle

accident two days ago. He sustained an isolated head injury with intraventricular hemorrhage and multiple large cerebral contusions. Three hours ago, he had an episode of severe intracranial hypertension (ICP 90mm Hg, MAP 50mm Hg, requiring volume plus epinephrine infusion for hypotension. Over the last two hours, his urine output has increased to 130-150 ml/hour (~8ml/kg/hr).

What is your differential diagnosis?What test would you order?

Case Study #3


Differential diagnosisPolyuria

1) Central diabetes insipidusDeficient ADH secretion (idiopathic, trauma, pituitary surgery,

hypoxic ischemic encephalopathy)

2) Nephrogenic diabetes insipidusRenal resistance to ADH (X-linked hereditary, chronic lithium,

hypercalcemia, ...)

3) Primary polydipsia (psychogenic)Primary increase in water intake (psychiatric), occasionally

hypothalamic lesion affecting thirst center

4) Solute diuresisDiuretics (lasix, mannitol,..), glucosuria, high protein diets, post-

obstructive uropathy, resolving ATN, ….

Case Study #3


Laboratory studies

Serum studiesSodium 155 mEq/L BUN 13 mg/dLChloride 114 mEq/L Creatinine 0.6 mg/dLPotassium 4.2 mEq/L Glucose 86 mg/dLBicarbonate 22 mEq/L Serum osmolality: 320 mosmol/kg

OtherUrine specific gravity 1.005, no glucose.Urine osmolality: 160 mosmol/kg

What are the main abnormalities?

Case Study #3


Laboratory studies

Major abnormalities

1) Hypernatremia2) Polyuria (inappropriately dilute urine)

What is the most likely explanation?

Case Study #3

Diabetes InsipidusCase Study #3

Diabetes Insipidus

DiagnosisCentral Diabetes insipidus

1) Polyuria2) Inappropriately dilute urine (urine osmolality < serum

osmolality)

May be see with midline defectsFrequently occurs in brain dead patients

What should you do to treat this child?

Case Study #3

Diabetes InsipidusCase Study #3

Diabetes Insipidus

• Treatment • Acute: Vasopressin infusion - begin with 0.5

milliunits/kg/hour, double every 15-30 minutes until urine flow controlled

• Chronic: DDAVP (desmopressin)

• Warning• Closely monitor for development of hyponatremia


HPI:A six year old, 25 kg, boy with severe asthma (S/P ECMO for a

previous exacerbation) presents with a two day history of severe vomiting and diarrhea to the Emergency Department.

Home meds:Albuterol MDI two puffs QID, Salmeterol MDI two puffs BID,

Prednisone 10mg daily, Fluticasone 220 mcg two puffs BID

PE: BP 70/40, HR 168, R 40, T39.0 C. He is very lethargic (GCS 11).

Poor perfusion with cool extremities, mottling, and delayed capillary refill, otherwise no specific system abnormalities.


What is your differential diagnosis?


Case Study #4


Differential diagnosis

Shock1) Cardiogenic

MyocarditisPericardial effusion

2) HypovolemicHemorrhage, excessive GI losses, “3rd spacing” (burns, sepsis)

3) DistributiveSepsis, anaphylaxis

Case Study #4


Laboratory studies

Serum studiesSodium 130 mEq/L BUN 43 mg/dLChloride 99 mEq/L Creatinine 0.6 mg/dLPotassium 5.7 mEq/L Glucose 48 mg/dLBicarbonate 12 mEq/L

OtherWBC: 13k (60% P, 30% L), HCT 35%, PLT 223kChest radiograph: no abnormalities

What are the electrolyte abnormalities?

Case Study #4

DiagnosisCase Study #4

Diagnosis

Major abnormalities

1) Hyponatremic dehydration

2) Hypoglycemia3) Hyperkalemia, mild4) Acidosis5) Azotemia

What is the most likely explanation for these findings?

Case Study #4 Adrenal Insufficiency


• 1o adrenal insufficiency (Addison’s disease)• Adrenal gland destruction/dysfunction (ie. autoimmune,

hemorrhagic)• most common in infants 5-15 days old

• 2nd adrenal insufficiency • ACTH deficiency (ie. panhypopituitarism or isolated ACTH)

• “Tertiary” or “iatrogenic” • Suppression of hypothalamic-pituitary-adrenal axis (ie.

chronic steroid use)



• Manifestations• Major hormonal factor precipitating crisis is mineralcorticoid

deficiency, not glucocorticoid.

• Dehydration, hypotension, shock out of proportion to severity of illness

• Nausea, vomiting, abdominal pain, weakness, tiredness, fatigue, anorexia

• Unexplained fever• Hypoglycemia (more common in children and tertiary)• Hyponatremia, hyperkalemia, azotemia



• Diagnosis• Critical level of suspicion in all patients with shock

• 1) Demonstration of inappropriately low cortisol secretion• Basal morning level vs. random “stress” level

• 2) Determine whether cortisol deficiency dependent or independent of ACTH secretion.• ACTH, cortisol 1o adrenal insufficiency • ACTH, cortisol 2nd or tertiary insufficiency

• 3) Seek a treatable cause



• What should you do to treat this child?



• Treatment• Do not wait for confirmatory labs

• Fluid resuscitation - isotonic crystalloid

• Treat hypoglycemia

• Glucocorticoid replacement - hydrocortisone in stress doses - 25-50 mg/m2 (1-2 mg/kg) IV

• Consider mineralocorticoid (Florinef®)


• HPI:• An eight month old infant with autosomal recessive

polycystic kidney disease presents with irritability. She is on nightly peritoneal dialysis at home. The lab calls a panic potassium value of 7.1 meq/L. The tech says it is not hemolyzed.

What do you do now?

Case Study #5

HyperkalemiaCase Study #5

Hyperkalemia

• Treatment

• Immediately repeat serum potassium. Do not wait for confirmatory labs especially if EKG changes

present.

• Anticipatory Stop potassium administration including feeds

Cardiac MonitorCardiac Monitor

• What is this rhythm?• What is your immediate treatment?

Case Study #5

HyperkalemiaCase Study #5

Hyperkalemia• Treatment (cont)• Control effects

• Antagonism of membrane actions of potassium Calcium chloride 10-20 mg/kg over 5 minutes; may repeat

x2

• Shift potassium intracellularly Glucose 1 gm/kg plus 0.1 unit/kg regular insulin Alkalinize (increase ventilator rate; Sodium bicarbonate 1 mEq/kg

IV) Inhaled 2 adrenergic agonist (albuterol)

• Removal of potassium from the body Loop / thiazide diuretics Cation exchange resin: sodium polstyrene sulfonate

(Kayexelate®) 1 gm/kg PO or PR (or both) Dialysis


• HPI:• A three year old boy is recovering from septic shock. He

received 150 ml/kg in fluid boluses in the first 24 hours and has anasarca. You begin him on a bumetanide infusion (Bumex®) for diuresis. He develops severe weakness and begins to hypoventilate. You notice unifocal premature ventricular beats on his cardiac monitor.

What is your differential diagnosis?What tests would you order?

Case Study #6


Laboratory studies

Serum studiesSodium 134 mEq/L BUN 11 mg/dLChloride 98 mEq/L Creatinine 0.4 mg/dLPotassium 2.4 mEq/L Calcium 9.2 mg/dLBicarbonate 27 mEq/L Phosphorus 3.2 mg/dL

OtherEKG: Unifocal PVC’s

What is the main abnormality?

Case Study #6


Laboratory studies

Major abnormality

1) Hypokalemia

What would you do now?

Case Study #6

HypokalemiaCase Study #6

Hypokalemia

• Treatment

• Oral • Safest, although solutions may cause diarrhea

• IV• Peripheral: do not exceed 40-50 mEq/L potassium - Avoid Avoid

temptation to rapidly bolustemptation to rapidly bolus• Central: 0.5 -1 mEq/kg over 1-3 hours, depending on severity

• Replace magnesium also if low• (25-50 mg/kg MgSO4)

SummarySummary

• Disorders of sodium, water, and potassium regulation are common in critically ill children

• Diagnostic approach must be considered carefully for each patient

• Strict attention to detail is important in providing safe and effective therapy

fluid and electrolyte emergencies in critically ill children ahmed khamis bamaga mbbs

Documents

case study

high urine osmolality

urine sodium excretion

decreasing urine output

diagnostic studies

face of hyponatremia

diminished renal blood

acute renal failure