Board Simulation: Pediatric Critical Care



Board Simulation: Pediatric Critical Care


Michael McHugh



In this chapter, a board simulation format is utilized to review a variety of pediatric emergencies.


QUESTIONS


Case 1

A 4-year-old boy was brought to your office because it was difficult to arouse him this morning. The parents recall no trauma. There are no medications at home that might have caused this. The family does not keep alcohol in the house. On your examination, the child is not moving, and does not rouse with stimulation. You note some diffuse swelling over the right parietal region. You palpate a fracture line of the parietal bone. The left pupil is 8 mm; the right pupil is 3 mm. There are no bruises noted. The rest of the examination is negative.



1. What is the most likely clinical diagnosis?


a) Toxic ingestion


b) Benign head trauma


c) Left focal seizure


d) Increased intracranial pressure (ICP) with impending herniation

View Answer

Answer

The answer is d. The presence of mental status changes makes this scenario most consistent with nonbenign head trauma. The CT scan demonstrated that this child had a left parietal skull fracture with an expanding epidural hematoma. Most simple linear skull fractures in children are not surgical emergencies and require no treatment. In this case, however, the patient had an epidural hematoma with increased ICP and impending uncal herniation. Epidural hematomas often develop secondary to laceration of the underlying middle meningeal artery, and the palpable skull fracture overlying the course for this artery provides a clue to the diagnosis. The new onset of a unilateral dilated pupil indicates that the uncus of the temporal lobe is being displaced medially.

Toxic ingestions usually provide symmetric, nonlocalizing, neurologic signs. There is nothing in the history to suggest the onset of a seizure disorder.

Clinical signs and symptoms of increased ICP in infants and children include:



  • Altered mental status


  • Vomiting


  • Cranial nerve III and VI palsies


  • Altered vital signs (increased blood pressure, bradycardia or tachycardia, decreased or irregular respirations)


  • Papilledema


  • Full fontanelle (infants)


  • Separated sutures (infants)


  • Decerebrate or decorticate posturing

No single treatment for increased ICP exists. Supportive measures include respiratory and circulatory resuscitation, elevation of the head to 30 degrees, seizure and fever control, and maintenance of an adequate blood volume. Medical management of acutely elevated ICP may include:



  • Airway protection using ICP protective strategies (full sedation, lidocaine, and paralysis)


  • Controlled hyperventilation (brief)


  • Mannitol and furosemide


  • Hypertonic saline (3% saline) and control of serum osmolality


  • Monitoring of ICP


  • Mild to moderate hypothermia


  • Dexamethasone


  • Induced barbiturate coma


  • Glycerol


Case 2 for Questions 2-4

An 18-month-old boy has had profuse watery diarrhea for 2 days. He has had poor oral intake and a low-grade fever. He is producing small amounts of dark urine. His
parents report he is hard to arouse. His eyes appear sunken. He has no localizing signs.



2. Which acid-base state is the child most likely to have?


a) Metabolic acidosis


b) Metabolic alkalosis


c) Respiratory alkalosis


d) Mixed metabolic alkalosis and respiratory acidosis

View Answer

Answer

The answer is a. Metabolic acidosis is the most common acid-base problem in pediatric emergencies. It results from a loss of bicarbonate ions or from a gain of hydrogen ions. This baby is hypovolemic and has lost large amounts of bicarbonate in his stool. Poor tissue perfusion and loss of base make metabolic acidosis the most likely acid-base state. Hypovolemia is the most common cause of shock in infants and children. Causes of hypovolemic shock include gastrointestinal hemorrhage, traumatic hemorrhage, fluid and electrolyte losses from gastrointestinal losses, and endocrinologic diseases such as diabetic ketoacidosis.

If electrolytes are checked, this child is most likely to have a normal anion gap acidosis (normal anion gap for a child <2 years is 16 ± 4). A bicarbonate level <12 has correlated with the need for hospitalization.



3. When lab values are drawn, his blood urea nitrogen (BUN) is 35 mg/dL and his creatinine is 1.0 mg/dL. What diagnosis best fits these lab values in this situation?


a) Prerenal azotemia


b) Henoch-Schönlein purpura


c) Hemolytic uremic syndrome


d) Acute tubular necrosis

View Answer

Answer

The answer is a. Azotemia and oliguria may be caused by renal, prerenal, or postrenal etiologies. Prerenal causes of azotemia include decreased cardiac output (as in cardiogenic shock) and decreased intravascular volume (as in hemorrhage, dehydration, and “thirdspacing” situations). Prerenal azotemia and hypovolemia cause the kidneys to preserve plasma volume. A BUN: creatinine ratio >20 suggests a prerenal state. If treated promptly, prerenal and postrenal etiologies are usually reversible. Untreated, this child could progress to acute tubular necrosis.

Henoch-Schönlein purpura is a vasculitic process mediated by the deposition of immunoglobulin A (IgA) containing immune complexes that typically present with the classic triad of a purpuric rash, crampy abdominal pain, and joint symptoms. Typically, the child is older than the one presented; the most common age distribution is from 3 to 10 years. There is frequently a history of a precedent upper respiratory infection. The clinical presentation of the child in question does not fit this diagnosis.

Hemolytic uremic syndrome is a syndrome of microangiopathic hemolytic uremia, thrombocytopenia, and acute renal failure occurring typically in children <3 years. The typical form of the disease follows a diarrheal infection with toxin-producing Escherichia coli. This disease is more common in the summer months. It has been associated with contact with animals carrying the toxin-producing bacteria.



4. You decide that the child in case 2 requires volume resuscitation. Which is the best fluid to prescribe?


a) 20 cc/kg 5% dextrose water with lactated Ringer solution (D5W/LR)


b) 10 cc/kg 5% albumin


c) 10 cc/kg 0.9% sodium chloride (NS)


d) 20 cc/kg 0.9% NS

View Answer

Answer

The answer is d. Isotonic crystalloids are the fluids of choice for volume resuscitation. The correct dose for most children is 20 cc/kg given as rapidly as possible. Using D5W/lactated Ringer solution will result in hyperglycemia. Lactated Ringer solution alone is an acceptable resuscitation fluid. Five percent albumin is an acceptable but expensive resuscitation fluid. Sufficient volumes of isotonic crystalloids, titrated to the adequacy of perfusion, are readily available and equally efficacious as resuscitation fluids. Unless there is a prior history of heart disease or a suggestion in the history of possible heart disease, the initial dose of fluid should be 20 mL/kg, given as quickly as possible (<15-20 minutes).

Jul 5, 2016 | Posted by in CRITICAL CARE | Comments Off on Board Simulation: Pediatric Critical Care

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