PEDIATRIC UPDATE 2008
Educational Objectives
| The goal of this program is to improve the diagnosis and management of metabolic emergencies and common illnesses
in children. After hearing and assimilating this program, the clinician will be better able to:
|
 | 1. Describe the management of dehydration, hypoglycemia, and hyponatremia in children.
|
| 2. Review the diagnosis of inborn errors of metabolism and other pediatric metabolic emergencies.
|
| 3. Compare the diagnostic specificity and sensitivity of urinalysis, using samples collected by different techniques.
|
| 4. Discuss the treatment options for children with bronchiolitis.
|
| 5. List the advantages of observation in children with otitis media, and identify children who may benefit from
treatment.
|
Faculty Disclosure
In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning
committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest.
Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a
proprietary business or commercial interest. For this program, the faculty and planning committee reported nothing to disclose.
Acknowledgments
Dr. Sharieff was recorded at 36th Annual Scientific Assembly, presented by the American College of Emergency Physicians,
State Chapter of California, Inc, and held May 31 to June 2, 2007, in Newport Beach, CA; Dr. Marmor was recorded
at Topics in Emergency Medicine, presented by the University of California, San Francisco, School of Medicine,
Division of Emergency Medicine, and held October 1-4, 2007, in San Francisco, CA. The Audio-Digest Foundation
thanks the speakers and the sponsors for their cooperation in the production of this program.
| PEDIATRIC ENDOCRINE AND METABOLIC EMERGENCIES —Ghazala Sharieff, MD, Associate Clinical Professor,
Children’s Hospital and Health Center, University of California, San Diego, School of Medicine, and Director of Pediatric
Emergency Medicine, Palomar-Pomerado Health System, San Diego, CA
|
| Severe dehydration: \>10% loss of fluid; hypotension—indicates severe dehydration; systolic blood pressure (BP) of 70
mm Hg plus twice age (in years) corresponds to fifth percentile (lower limit for BP); BP goal, ≥90 mm Hg plus twice age
(corresponds to ≥50th percentile); maintenance fluids—give 4 mL/kg per hour up to 10 kg; add 2 mL/kg per hour from 10
to 20 kg; add 1 mL/kg for each kilogram \>20 kg
|
| Hypoglycemia: normal blood glucose (BG)—\>30 mg/dL in neonates; \>40 mg/dL in older children; treatment in
neonates—begin with 2 mL/kg of 10% dextrose (D10) solution; increase up to 10 mL/kg; avoid D25 and D50 solutions,
because hyperosmolar therapy may injure veins and cause intracranial hemorrhage; treatment in older children—2 to 4
mL/kg of D25 solution for older children; 1 to 2 mL/kg of D50 solution for adolescents; glucagon—rarely necessary in
children; when appropriate, give 0.1 to 0.2 mg/kg intramuscularly (IM)
|
| Hyponatremia: may occur when parents give water to young infant; presentation—seizures, often unresponsive to anticonvulsants;
children often require intubation; empiric treatment—if child (with consistent history) does not respond
to lorazepam (eg, Ativan), administer bolus of 4 to 5 mL/kg of 3% saline (not harmful; increasing level of serum sodium
above seizure-inducing range may eliminate need to intubate); calculate appropriate sodium replacement over 24-hr period;
body temperature—hyponatremic seizures also associated with hypothermia (average body temperature, 35.5°C
vs 37.2°C for children with normal sodium levels)
|
| Inborn errors of metabolism: nonspecific presenting symptoms (eg, vomiting, lethargy, seizure); encephalopathic with
low pH, and low bicarbonate; no abnormal findings on computed tomography (CT) of head or sepsis work-up; infants often
unresponsive and may have low-grade fever; etiology —altered protein synthesis results in accumulation of metabolite;
important questions for parents—unexplained deaths in family (especially boys); acute deterioration after normal
period; diet (eg, recent introduction of new food); unusual odors (eg, musty, sweaty, fruity); abnormal movements (eg, bicycling;
tongue-thrusting); diarrhea (generally absent); work-up—ammonia level and blood gas measurements; urinalysis
(UA) when appropriate; diagnosis—elevated ammonia without acidosis signals urea cycle defect; acidosis without elevated
ammonia, plus reducing substances in urine, signals defect in amino acid metabolism; acidosis with or without elevated
ammonia signals organic acidemia (if UA reveals decreased ketones, consider defect in fatty acid oxidation); other
considerations—in hypoglycemic children, check BG after replacing glucose (hypoglycemia may return); consider giving
maintenance fluid (eg, D15) through central line in children with persistent hypoglycemia
|
| Urea cycle defects: most common inborn error of metabolism, usually caused by deficiency in ornithine transcarbamylase;
UA reveals spindle-shaped crystals; treatment includes arginine replacement
|
| Organic acidemias: children may have elevated ammonia or ketones in urine; children always hypoglycemic and appear
ill; management—perform complete blood cell count (CBC) and culture; cover with antibiotics
|
| Galactosemia: rare; newborn may present with Escherichia coli sepsis; UA reveals reducing substances and galactosuria;
cataracts sometimes present
|
| Hereditary fructose intolerance: child exhibits vomiting, lethargy, seizures, and failure to thrive; disorder manifests after
introduction of fructose; treatment—hydrate; replace glucose; check electrolytes; check pH of urine; give benzodiazepines
for seizures; administer bicarbonate in patients with organic acidemia; perform complete septic work-up; begin
antibiotic therapy
|
| Bicarbonate administration: may be life-saving in patients with organic acidemias (but avoid in patients with diabetic ketoacidosis
[DKA]); begin with 1 mEq/kg
|
| Diabetic ketoacidosis: diagnostic criteria—BG \>300 mg/dL; metabolic acidosis; ketonemia; symptoms include polyuria
and vomiting; abdomen distended due to distention of liver capsule; Kussmaul respirations; work-up—draw extra
red-top tube of blood for additional tests; venous blood sufficient for blood gas measurements; hydration—avoid overloading
fluid (causes BG to fall too quickly; avoid decreasing BG by \>100 mg/dL per hour); in normotensive patients,
begin with bolus of 10 mL/kg; do not exceed 4 L/m2 ; avoid administering \>50 mL/kg of fluid during first 4 hr, unless
patient in shock; insulin—avoid bolus (will decrease BG too fast); repeat BG measurement before beginning insulin
infusion; begin infusion at 0.1 U/kg per hour; bicarbonate—generally avoid (may increase length of stay; may cause
cerebral edema)
|
| Cerebral edema and herniation in DKA: study showed degree of acidosis and rate of hydration most reliably predict risk;
no patients with pH<7.1 developed herniation; administering \>50 mL/kg of fluid over first 4 hr increases risk; retrospective
study found risk increased among patients with low levels of bicarbonate, high levels of serum urea nitrogen
(BUN), and low levels of carbon dioxide; patients who later developed cerebral edema appeared sicker at presentation;
rates of fluid and sodium replacement and insulin therapy did not affect risk; bicarbonate administration associated
with worse outcome; outcomes—patients at risk for neurologic sequelae and death
|
| Idiopathic ketotic hypoglycemia (IKH): diagnostic criteria—hypoglycemia; ketonuria; incidence—most common
cause of noninsulin-induced hypoglycemia; usually occurs in children <5 yr of age (more frequently in boys); often precipitated
by prolonged fast; treatment—IV dextrose for rescue; small frequent meals for prevention; disease course—
typically resolves spontaneously by 10 yr of age; multiple visits to ED should trigger additional work-up for, eg, insulinoma
|
| Thyroid abnormalities: congenital hypothyroidism—children typically large for gestational age and have prolonged
jaundice, large tongues, coarse cries, umbilical hernias, and delayed deep tendon reflexes; laboratory studies show elevated
thyrotropin (TSH) and low free thyroxine (T4 ); thyroid storm—rare in children; often identified by screening; signs and
symptoms include tremor, mania, high fever, and exophthalmos; congestive heart failure (CHF) and pulmonary edema may
develop; laboratory studies show low levels of TSH; treatment includes propranolol (to decrease hypermetabolic state), cooling
blankets, and dexamethasone (eg, Decadron); propylthiouracil (PTU) must be administered before iodine; aspirin contraindicated;
neonatal thyrotoxicosis—may occur in neonates whose mothers took PTU during pregnancy; presentation
includes tachycardia and fever; TSH and T4 levels may aid diagnosis; signs and symptoms include goiter, poor weight gain,
irritability, diarrhea, vomiting, and craniosynostosis (small head); clinical diagnosis (laboratory results may not be accurate
during first few days of life); treatment same as for thyroid storm
|
| Congenital adrenal hyperplasia: ambiguous genitalia easier to recognize in girls (generally diagnosed at birth);
etiology—deficiency in 1 of 5 enzymes (most commonly, 21-hydroxylase) involved in production of cortisol; crash occurs
after maternal hormones clear; signs and symptoms—decreased production of aldosterone; hyperkalemia; urinary salt wasting;
hyperpigmentation (increased production of melanin); vomiting and dehydration, sometimes low-grade fever; arrhythmias
(caused by hyperkalemia and acidosis); treatment—normalize sodium and potassium levels; initiate corticosteroid
therapy; treat arrhythmias, if present; replace glucose and continue checking BG levels; initiate IV hydration (often with D5
normal saline); begin hydrocortisone therapy with 25 mg for young children and 50 mg for older children (draw extra red-
top tube of blood before initiating steroids)
|
| FEVER WITHOUT A SOURCE —Andrea K. Marmor, MD, Assistant Clinical Professor of Pediatrics, University of California,
San Francisco, School of Medicine
|
Urinary Tract Infections (UTIs)
| Incidence: most common bacterial cause of fever without source (FWS)
|
| Screening recommendations: all infants <3 mo of age with FWS; female infants up to 12 mo of age; uncircumcised
boys <1 yr of age; circumcised boys <6 mo of age; other factors to consider include duration of fever, temperature, and
presence of symptoms (eg, runny nose, rash) that suggest viral infection
|
| Urine collection: catheter—most accurate method; high success rate; relatively invasive; collection bag—easier; noninvasive;
risk for contamination from skin or stool
|
| Urinalysis (UA): leukocyte esterase—80% to 90% sensitive (sensitivity increases when other factors [eg, number of
white blood cells] considered); 75% to 85% specific; presence of bacteria does not increase sensitivity or specificity;
nitrites—high specificity but very low sensitivity; considerations in young infants—accuracy of dipstick may be poor because
they do not build up as much inflammation, or urine may not be in bladder long enough to accumulate sufficient
amounts of leukocyte esterase and nitrites; sensitivity and specificity may vary with age; study data do not support this;
predictive value of UA—depends on age; high-risk patient most affected by positive UA, while in low-risk patient, negative
UA most helpful; high pretest probability for UTI—very young patients; negative UA does not rule out UTI (further testing
indicated; consider culture and admission for observation); positive UA indication for treatment; predictive value of UA—
negative test has high negative predictive value in low-risk patients (rules out UTI); positive test has high positive predictive
value in high-risk patients (treatment indicated); sample collection—sensitivity using bag-collected samples similar to
that of catheter-collected samples, but specificity lower; catheter collection preferred if false-positive result has invasive
implications
|
| Cultures: samples collected by bag may result in false positives and false negatives; predictive value of culture from
bagged samples similar to that of UA (negative culture helps rule out UTI in low-risk patients); for high-risk patients, use
catheter-collected samples for culture; for low- to moderate-risk patients, discuss options with parents, including implications
for false-negative and false-positive results
|
| Treatment of pyelonephritis: admit very ill children and those <3 mo of age; treat others as outpatients; administer first
dose of antibiotics and observe patient before discharging from ED (especially important in young infants because of high
risk for bacteremia); follow up to determine response to therapy (children should respond within 48 hr); antibiotics—10 to
14 days; regional resistance patterns of E coli affect choice of antibiotic
|
Bronchiolitis
| Background: common lower respiratory infection in children; may result in hospitalization; pathogens—respiratory
syncytial virus (RSV) most common cause; association with asthma—subset of patients develops asthma; variable treatment
responses may reflect heterogeneous etiologies
|
| Diagnosis: based on history and physical examination; routine laboratory tests and radiologic studies not recommended
|
| Treatment: albuterol—several studies show no clinical benefit, although it may reduce bronchospasm in children with
undiagnosed asthma; racemic epinephrine—may decrease pulmonary edema; associated with modest short-term improvement
(superior to β-agonists); does not affect clinical outcomes (eg, admission rates, length of stay); does not cause
rebound in children with bronchiolitis; corticosteroids—meta-analyses have conflicting conclusions about efficacy;
greater effect seen among patients with recurrent wheezing (ie, asthma likely); recommendations—mainstay of treatment
supportive care (fluid; nasal clearance and suction; O2 and respiratory support as needed); carefully monitored trial of
bronchodilators and corticosteroids acceptable in very ill patients, but should be discontinued if no clinical response observed;
delivery of inhaled medications—solution of hypertonic saline may improve short-term response to bronchodilator;
avoid use of hypertonic saline alone
|
| Supplemental O2: hypoxia, most frequent reason for hospitalization; indication—previously healthy infants with O2
saturation persistently <90% on room air; in-home administration—good option if hypoxia only reason for hospitalization;
observation—study showed that status changed in 20% of children observed for 8 hr in ED (need for admission or
supplemental O2 changed)
|
Otitis Media (OM)
| Treatment vs observation: observation without antibiotics—standard in Europe; benefits include fewer adverse effects
and reduced bacterial resistance; disadvantages may include longer duration of illness and risk for complications; antibiotic
therapy—associated with somewhat higher cure rates (86% vs 70% at day 3), somewhat lower rates of clinical failure, and
modest reduction in duration of symptoms; greatest effect seen in very young or very ill children; complications—no significant
difference between treatment and observation
|
| Management guidelines: consider diagnostic certainty when deciding whether to initiate antibiotic therapy; assess and
treat pain associated with OM; diagnostic criteria—acute onset of symptoms; evidence of middle ear effusion (fluid
behind tympanic membrane) and inflammation (eg, erythema, bulging, pus); children < 6 mo of age—antibiotic therapy
indicated; older children—may benefit from antibiotics if severely ill or diagnosis more certain, ie, child has many
physical findings associated with acute bacterial OM; observation with follow-up generally sufficient; discuss options
with parents; explain rationale for observation; consider reliability of parents
|
| Pathogens: OM commonly caused by Streptococcus pneumoniae; introduction of pneumococcal vaccine has reduced incidence
of recurrent OM; relative importance has increased for Haemophilus influenzae and strains of S pneumoniae not
covered by vaccine; H influenzae, most common pathogen recovered in cases of persistent OM
|
| Persistence: symptoms return within 14 days of treatment; symptoms that return after 14 days considered new infection
(ie, does not represent treatment failure)
|
| Antibiotics: initial therapy—high-dose amoxicillin (80-90 mg/kg per day) associated with 80% cure rate; broader coverage
(eg, amoxicillin plus clavulanic acid) recommended for more severely ill children; other cephalosporins may be used
in children with non–type-1 penicillin allergy; erythromycin plus sulfamethoxazole or high-dose azithromycin acceptable
alternatives for patients with type-1 allergy; persistent OM—50 mg/kg of ceftriaxone for 3 days (better than single dose);
high-dose azithromycin (some studies show superiority over amoxicillin/clavulanic acid); fluoroquinolones (eg, gatifloxacin)
may become more important
|
Simple Febrile Seizures
| Management: observation sufficient; simple febrile seizure does not increase risk for serious bacterial illness (eg, meningitis),
compared to fever alone; recommendations—follow guidelines for assessing and managing FWS; no benefit
shown for laboratory tests or imaging; electroencephalography not useful for diagnosis, management, or predicting risk
for future seizures; anticonvulsants and around-the-clock antipyretics have no benefit (inflammatory cytokines, rather
than elevated temperature, may be responsible for seizure); children who require additional work-up—infants <6 mo of
age
|
Suggested Reading
Bajaj L et al: A randomized trial of home oxygen therapy from the emergency department for acute bronchiolitis. Pediatrics
117:633, 2006; Bowker R et al: Guidelines for the investigation and management of a reduced level of consciousness
in children: implications for clinical biochemistry laboratories. Ann Clin Biochem 44(pt 6):506, 2007; Fiordalisi I et al: An
18-yr prospective study of pediatric diabetic ketoacidosis: an approach to minimizing the risk of brain herniation during treatment.
Pediatr Diabetes 8:142, 2007; Hodson EM et al: Antibiotics for acute pyelonephritis in children. Cochrane Database
Syst Rev 4:CD003772, 2007; Kwon KT, Tsai VW: Metabolic emergencies. Emerg Med Clin North Am 25:1041,
2007; Leung AK, Robson, WL: Febrile seizures. J Pediatr Health Care 21:250, 2007; Patel H et al: WITHDRAWN:
Glucocorticoids for acute viral bronchiolitis in infants and young children. Cochrane Database Syst Rev 1:CD004878, 2008;
Ramakrishnan K et al: Diagnosis and treatment of otitis media. Am Fam Physician 76:1650, 2007; Rowland K et al:
Clinical inquires. What are the causes of elevated TSH in a newborn? J Fam Pract 57:185, 2008; Shaikh N et al: Does this
child have a urinary tract infection? JAMA 298:2895, 2007; Spiro DM, Arnold DH: The concept and practice of a wait-
and-see approach to acute otitis media. Curr Opin Pediatr 20:72, 2008; Steiner MJ et al: Urine specific gravity and other
urinary indices: inaccurate tests for dehydration. Pediatr Emerg Care 23:298, 2007; Walsh P et al: Comparison of nebulized
epinephrine to albuterol in bronchiolitis. Acad Emerg Med 15:305, 2008; Waseem M et al: A child with abdominal
pain and hyperglycemia: is it diabetic ketoacidosis? Pediatr Emerg Care 24:39, 2008.
|
