UMEM Educational Pearls - Pediatrics

As we head into the warmer months we should remember that every year there are reports of a toddler left in his car seat for 15 min who comes in uresponsive with hyperthermia. 

Heat related illnesses are a continuum from heat cramps to heatstroke.  The hallmark of heatstroke is hyperthermia with mental status changes and when identified rapid cooling must be initiated.  Mortality for heatstroke is reported as high as 80%. 

Children are more susceptible to heat stroke because of a greater surface area to body mass ratio, higher metabolic rates, less developed sweating mechanisms, and inability to always remove themselves from the hot environment.

The quickest and easiest way to cool a conscious patient is by evaporation.  Changing water from a liquid to a vapor is an endothermic process.  Removal of all clothes, followed by misting or wiping with tepid water of the entire skin is very effective.  Having a fan pointed at the child can enhance this method.   

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Hemolytic-uremic syndrome (HUS)

• Characterized by hemolytic anemia (pallor on exam), acute renal failure (oliguria or anuria by history), and thrombocytopenia (petechiae).
• HUS is one of the most common causes of acute renal failure in children.
• Two types: diarrhea-associated (shiga toxin+ or D+) which is more common and has a more favorable prognosis, and non diarrhea-associated (atypical or sporadic or D-).
• Most common age at presentation is during infancy or young childhood.
• Pediatric HUS is a true medical emergency.
  • Resuscitation with blood products frequently is required, but it is crucial to provide volume carefully because renal function may be severely compromised.
  • Dialysis is required if anuria persists for 12+ hours or for severe hyperkalemia (>6.5mEq/L) Some patients may benefit from plasmapheresis, but full renal recovery is not certain.

Parainfluenza viruses (types 1, 2, 3) account for more than 65% of all cases. The different serotypes have seasonal patterns, with type 1 and 2 occuring in the autumn and being the most common pathogens associated with croup while type 3 is more frequent in the spring and summer and is associated with pneumonia and bronchiolitis.

Infections are rarely associated with high fever and usually last 4 to 5 days. There are no distinctive laboratory abnormalities, and diagnosis is generally made clinically.  Chest and neck xray may demonstrate a “steeple sign” from narrowing of the subglottic region.  Viral cultures and immunofluorescent rapid antigen identification can be obtained from respiratory secretions.  Specific antiviral therapy is not available. Aerosolized epinephrine can be given to severely affected, hospitalized patients to decrease airway obstruction.  Parental (>0.3mg/kg) and oral ((0.15mg/kg) dexamethasone have been demonstrated to lessen the severity and duration of symptoms and hospitalization in patients with moderate to severe croup.  
 

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• For children under 5 years of age the rate of missing an appendicitis remains very high.  (57%-67%)
• The rate of misdiagnosis increases as the age decreases. 
• In cases of missed appendicitis the most common incorrect diagnosis is gastroenteritis.
• Think twice before you label vomiting alone, or diarrhea alone as gastroenteritis.
• If an appendicitis is missed there is an increased risk of perforation, abscess formation, and higher morbidity. 

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Rocky Mountain spotted fever (RMSF)

Systemic small vessel vasculitis caused by R rickettsii which is transmitted by a tick bite.

Clinical features: fever, headache, myalgia, nausea, vomiting, and characteristic rash. Rash usually appears before the sixth day of the illness initially on the wrists and ankles, and spreads to the trunk within hours.  Initially. It is erythematous and macular, later becoming petechial.

Laboratory findings: thrombocytopenia, anemia, and hyponatremia.

Complications: meningitis, multiorgan involvement, DIC, shock, and death. 

Treatment: doxcycycline (even despite the risk of dental staining in children younger than 8 years old)

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• Pediatric seizures are common and 4-6% of all children will have a seizure by the time they are 16 years old.
• Afebrile neonatal seizures require an evaluation of electrolytes, glucose, calcium, magnesium, LP, blood and urine cultures.
• Simple Febrile seizures usually do not require any lab testing or admission if the child appears well.
• Dilution of formula with too much water is a common cause of hyponatremic seizures in infants.  (Treat with 3ml/kg of 3% hypertonic saline)
• Complex febrile seizures have a higher risk for meningitis than simple febrile seizures, so perform an LP, give antibiotics, and admit.
• When intubating for Status Epilepticus consider using thiopental or propofol for induction given their antiepileptic properties.

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• An acute bacterial infection of a joint.
• Peak incidence in children is younger than 2 years of age.
• Risk factors:
  • history of trauma
  • preceding URI
  • immunodeficiency
  • hemoglobinopathy
  • Diabetes.
• Age is the most important determinant of cause.
  • In all age groups, S aureus is the primary organism accounting for more than 50% of cases.
  • Among neonates, enteric gram-negative organisms and group B Streptococcus are the most frequent causes.
  • Group A Streptococcus, S pneumoniae, and K kingae are common causes in children younger than 5 years old.
• Blood culture, joint fluid aspiration and analysis, gram stain, and culture of fluid is recommended.
• In pyogenic arthritis, the joint fluid is usually cloudy and has a leukocyte count of at least 50 x 10000/mcL, with a predominance of polymorphonuclear cells, low glucose concentrations, and high protein values.
• Treatment involves a combination of parenteral antibiotics, surgical drainage, and decompression of the affected joint.
• All children who have pyogenic arthritis of the hip or shoulder require prompt open surgical drainage and irrigation to prevent permanent joint damage as the increased intra-articular pressure can compromise blood flow resulting in avascular necrosis of the femoral or humeral head and predisposing the patient to dislocations.
• Open surgical drainage of other joints usually is not required.

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Epstein-Barr virus (EBV)-associated infectious mononucleosis (IM) 

Most commonly presenting clinical findings: fever, fatigue, exudative pharyngitis, lymphadenopathy, and hepatosplenomegaly. 

Self-limited illness that lasts an average of 2 - 3 weeks. 

Treatment is primarily supportive.  Use of ampicillin, amoxicillin, or penicillin during the acute phase not indicated and may result in the development of a morbilliform rash, which studies have suggested may occur in more than 50% of the cases.  Antiviral therapy is not recommended. Splenic rupture occurs in about 1 - 2:1000 cases.  Therefore, avoidance of activities that increase the risk for injury is recommended until splenomegaly has resolved. 

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Bradycardia in children is most often caused by hypoxemia but can also be caused by acidosis, elevated ICP, vagal stimulation, heart blocks or overdoses. 

First degree heart block in otherwise healthy children can be caused by infectious diseases, myocarditis, rheumatic fever, Lyme disease and congenital heart disease.

Third degree heart block can be congenital, caused by maternal connective tissue disorders such as Lupus, or may result from cardiac surgery.

Any infant presenting with a third degree heart block should have an investigation for neonatal lupus. 

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The most common arrhythmias in children presenting to the ED are:

• Sinus tachycardia (50%)
• SVT (13%)
• Bradycardia (6%)
• Atrial Fibrillation (4.6%)

Atrial fibrillation in children is irregularly irregular with disorganized atrial activity with atrial rates ranging from 350-600 BPM. 

Children at increased risk of developing atrial fibrillation include those with underlying structural heart defects and hyperthyroidism.

Hemodynamically stable children have several treatment options including digoxin, amiodarone, propranolol, esmolol, or procainamide for ventricular rate control.

Hemodynamically unstable children need immediate synchronized cardioversion with 0.5 - 1 J/kg.  (don't forget light sedation.)

References:

Sacchetti A, Moyer V, Baricella R, et al. Primary cardiac arrhythmias in children. Pediatr Emerg Care 1999;15:95-98

Doniger S. Pediatric Dysrhythmias. Pediatric Emergency Medicine Reports. Sept 2008. Vol 13, No 9 (This was edited by a UMMS Combined EM/PEDS graduated Dr. Jim Colletti who is Associate Residency Director, Emergency Medicine, Mayo Clinic College of Medicine, Rochester, MN.)

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Six indications that would lead you to suspect SVT in children:

• history incompatible (no history fever, volume loss, hemorrhage or pain
• P waves absent /abnormal
• HR does not vary with activity
• Abrubt rate changes
• Infants : rate usually >220
• Children : rate usually >180

Remember in the stable child treat withe Adenosine 0.1mg/kg rapid IV push followed by rapid flush.

In the unstable child treat with synchronized cardioversion 0.5 -1 Joules/kg.

• Burn injuries are common in children and are the 3rd leading cause of unintentional injuries in children age 0 to 18 yrs, only behind MVCs and drowning.
• Burns greater than 20% TBSA require agressive fluid resuscitation. Lactated Ringer's is the most commonly used fluid. 
• Parkland Burn Formula:  LR over 24 hours = 4mlxkgx %BSA burned. 1st half over 1st 8 hours, 2nd half over subsequent 16 hours.  Add maintenance fluids to this amount for patients < 30 kg.
• Urine output is the best way to assess adequate fluid resuscitation.  Place a foley and goal output is 1-2 ml/kg/hr in children.  (0.5 to 1 ml/kg/hr in adults)
• Oligoanalgesia is very common in pediatric patients.  Use morphine 0.1 mg/kg IV/IM or Oxycodone 0.1 mg/kg po.
• 6% of burned children < 12 years old are victims of abuse.  So keep a high index of suspicion in children with burns. 

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Next time you have to do a full septic work up on a 2 month old with a fever of 104 F consider giving Ketamine 3mg/kg IM before even starting.  Then you can obtain your cath urine, IV, and LP with a calm pain free patient!!

Ketamine induces a catatonic state that provides sedation, analgesia, and amnesia.  It does not affect pharyngeal-laryngeal reflexes and the patient maintains a patent airway.  This makes it very useful when fasting is not assured.   

Route          Onset          Duration             Dose

  IM            3-5 min         20-30min         3-5 mg/kg

  IV             1 min            5-10 min          1-2 mg/kg

Propofol is an IV hypnotic that is made in a soy-based emulsion containing soybean oil, egg lecithin, and glycerol.  It has a very rapid onset time (10-50 seconds) and a brief duration of action making it ideal for ED sedation.  Children have a more rapid metabolism of propofol than adults.  Propofol has been shown to be safe and effective for Pediatric ED sedation in several studies.  

Pearls on Propofol

• Dosing is 1mg/kg bolus than 0.5 mg/kg IV q 1-2 min until desired sedation occurs
• Due to high lipid concentration can cause pain at injection site in up to 70% of patients.  This can be prevented by applying a rubber tourniquet well above IV site and injecting 0.5 mg/kg of lidocaine 30 seconds before injecting the propofol. 
• Use is contraindicated in those with allergies to Eggs, Soy, or sulfites, or those with mitochondrial disorders
• PRIS (Propofol Infusion Syndrome) was described in 1992 with case reports of children dying due to metabolic acidosis, rhabdomyolysis, and refractory heart failure when receiving high doses (>4mg/kg/h) for >48 hours.  And it is more associated with children < 4 years old. 
• So while safe for pediatric procedural sedation don't use propofol as a drip for intubated children.

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• Bronchiolitis is the most common lower respiratory tract disease in infants, and RSV (Respiratory syncytial virus) bronchiolitis is the leading cause of hospitalization in infants.  It will infect 90% of children by 2 years of life.
• Bronchiolitis "season" in the US is typically December to March but it does occur year round. 
• Pathology is caused by respiratory epithelial cell death that results in inflammation, edema, smooth muscle contraction, bronchoconstriction and mechanical obstruction by cellular debris and mucus plugging.
• History that suggest Bronchiolitis is cough, rhinorrhea, fever
• Most common PE findings are runny nose, tachypnea, wheezing, cough, crackles, use of accessory muscles,  and/or nasal flaring.
• Respiratory distress, dehydration, sepsis, and RSV associated apnea are feared severe complications.
• RSV associated apnea may be the presenting symptom in some infants. 
  • Infants at greatest risk for this are younger (usually < 3 months), hx of prematurity, hx of apnea of prematurity, and those who are early on in the illness.

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SIDS

Sudden infant death syndrome (SIDS) is defined as the sudden death of an infant younger than 1 year that remains unexplained after a thorough case investigation, including the performance of a complete autopsy, examination of the scene of death, and review of the clinical history.

SIDS is the single most common cause of death in infants aged 1 mo to 1 yr

Education is key for prevention of these tragic events:

Following the "Back to Sleep" campaign, federal SIDS researchers have conducted annual surveys to examine how infant sleep practices and SIDS rates have changed.  The rate of prone sleeping for infants decreased from approximately 75% in 1992 to a low of 11.3% in 2002

Since 1992, SIDS rates have fallen approximately 58%. In 2002, the National Center for Health Statistics reported a total of 2295 SIDS deaths nationwide for a SIDS rate in the United States of 0.51 per 1000 live births.

Bed-sharing may lead to compromise of the infants' airway because the infant may be suffocated by soft, loose bedding or a sleeping adult.

Cosleeping on a couch or sofa is associated with an unusually high risk for SIDS and should be avoided.

How do we know if we really need to put all those red eyes sent in from daycare centers and schools on antibiotics? The following study shows us why.

Bacterial Conjunctivitis in Children

• Prospective study in a children’s hospital ED
• Conjunctival swabs for culture were obtained from patients aged 1 mo - 18 yrs presenting with red or pink eye and/or the diagnosis of conjunctivitis
• 111 patients enrolled over one year
• Mean age of 33.2 mos, 55% male
• 87 patients (78%) had positive bacterial cultures
  • Nontypeable H influenzae = 82%
  • S pneumoniae = 16%
  • Staphylococcus aureus = 2.2%
• The combination of a history of gluey or sticky eyelids and the physical finding of mucoid or purulent discharge had a post-test probability of 96% that the infection was bacterial.(So when both these are present you definitely should treat)
• And since the majority of these children (78%) had positive cultures even if they only had a pink eye it is reasonable to use empirical ophthalmic antibiotic therapy in children who present with the complaint of a pink eye.

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With the cooler weather on us all our favorite viral infections will start to appear.  Included in this is the "slapped - cheek disease" Erythema infectiosum. 

Erythema Infectiosum

• An acute viral illness caused by parvovirus B-19
• Usually is seen in the winter and spring months
• Presents with mild fever, itching, headache, and arthralgias
• Usually have an erythematous, erysipeloid rash on the cheeks (slapped look) and a reticular rash (lace-like) on the arms
• No test are needed
• Management is supportive
• Children with chronic hemolytic anemias can develop an aplastic crisis from this infection

Pediatric Discitis is an intervertebral disc infection due to hematogenous spread to vascular channels in cartilage that disappear later in life.  In 1/3 of patients it is caused by S. aureus.

Presenting Features

• age <2.5 years (75%) 
• Refuse or difficult to walk  (56%)
• Back/neck pain (25-45%) ( 100%>3years)
• Hx of fever (28-47%)
• lumbaosacral area (78-82%)
• Mean ESR 39-42
• WBC> 10,500 (50%)
• Abnormal MRI 90-100 %

Management is to exclude more severe disease (osteomylelitis,abscess, tumor) and antibiotic use is debatable.  Remember children this age rarely complain of back pain. 

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Popsicle or cold panniculitis is an inflammation of the subcutaneous fat after prolonged exposure to cold.  It is thought to occur more often in infants and young children because they have a higher percentage of saturated fatty acids than older children and adults.  Pediatric patients may present to you to be evaluated/ruled out for abuse by social workers, schools, or police and if you have the correct history it is easy to dispo quickly.

Clinical Features of Popsicle Panniculitis

• Absence of systemic signs
• Minimal pain, with or without
• Skin is red to purplish, indurated, may have discrete nodules or plaques
• perioral location for popsicles, but may occur at any other area of skin exposure
• resolves in 2-3 weeks without scarring
• hyperpigmentation may persist
• arises within hours to to 1-2 days after exposure to a cold object

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