A 9-month-old boy is brought to the emergency department by his parents as he is not "acting like himself." The parents report that he has always been a fussy baby and often awakens multiple times a night. However, yesterday he cried the entire night and seemed more tired than usual this morning. The infant typically eats yogurt and formula for breakfast but refused to eat this morning and vomited 3 times. His mother says, "He may have hit his head on the floor after climbing onto and then rolling off the couch 2 days ago. He recently started crawling and often bumps into furniture around the house." The infant was born at term via an uncomplicated vaginal delivery. He was evaluated several times in the emergency department between ages 3 and 5 months for fussiness and was diagnosed with colic. His mother is currently taking antibiotics for bacterial pharyngitis; otherwise, there are no sick contacts or contributory family history. Temperature is 37 C (98.6 F) and pulse is 125/min. Height and weight are at the 75th and 50th percentiles, respectively. On examination, the infant is lethargic. The lungs are clear to auscultation and there are no murmurs. The abdomen is soft and nondistended. A small bruise is present on the buttocks; there are no additional rashes, lesions, or bruises. The infant's airway is secured, and his condition is stabilized. Which of the following is the best next step in management of this patient?

Question

A 9-month-old boy is brought to the emergency department by his parents as he is not "acting like himself."  The parents report that he has always been a fussy baby and often awakens multiple times a night.  However, yesterday he cried the entire night and seemed more tired than usual this morning.  The infant typically eats yogurt and formula for breakfast but refused to eat this morning and vomited 3 times.  His mother says, "He may have hit his head on the floor after climbing onto and then rolling off the couch 2 days ago.  He recently started crawling and often bumps into furniture around the house."  The infant was born at term via an uncomplicated vaginal delivery.  He was evaluated several times in the emergency department between ages 3 and 5 months for fussiness and was diagnosed with colic.  His mother is currently taking antibiotics for bacterial pharyngitis; otherwise, there are no sick contacts or contributory family history.  Temperature is 37 C (98.6 F) and pulse is 125/min.  Height and weight are at the 75th and 50th percentiles, respectively.  On examination, the infant is lethargic.  The lungs are clear to auscultation and there are no murmurs.  The abdomen is soft and nondistended.  A small bruise is present on the buttocks; there are no additional rashes, lesions, or bruises. The infant's airway is secured, and his condition is stabilized.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_bfef_15bf_8f63_83f02bc7265b_MD0005_00 Infants are particularly prone to abusive head trauma (AHT) as they have a large head-to-body ratio and weak neck muscles, making their heads unstable and vulnerable to coup-contrecoup injuries. In addition, the infant brain is incompletely myelinized, making it more susceptible to shearing forces during shaking. coup-contrecoup CT scan of the head is the preferred method for evaluating suspected AHT in a symptomatic patient (eg, lethargic, vomiting), as it is fast, widely available, and cost-effective. This patient is clinically unstable, and after the primary survey is complete and the airway secured, emergency CT scan of the head is required to determine whether neurosurgical intervention is required. CT scan detects intracranial bleeding in addition to cerebral edema and hypoxic-ischemic changes. Subdural hematomas, caused by shearing of the bridging veins, are the most common bleed seen in this setting and on imaging appear as crescents overlying the brain. They typically have a mixed-density pattern due to varying stages of injury, compared with the homogenous hyperdense pattern seen in accidental head trauma. mixed-density pattern On the other hand, in a situation that is not time sensitive and in which the patient is asymptomatic, MRI may be performed to provide more detail regarding the extent and timing of the injury while avoiding radiation exposure. (Choice B) A lumbar puncture is performed when meningitis is suspected. Although meningitis can cause lethargy and vomiting in an infant, this patient's history of trauma makes an intracranial bleed more likely. (Choice C) This patient is lethargic and vomiting, likely from increased intracranial pressure, and first requires an emergency CT scan of the head. Once his condition is stabilized, a skeletal survey may be performed to evaluate for other injuries suspicious for abuse, such as posterior rib fractures, metaphyseal corner fractures, and fractures in different stages of healing. If a patient is stable with a normal neurological examination, a skeletal survey may be performed first. (Choice D) Although abdominal trauma can be associated with AHT, this patient's vomiting and altered mental status are highly concerning for life-threatening intracranial hemorrhages requiring emergency CT scan of the head. (Choice E) Ultrasound of the head is used primarily to grade intraventricular hemorrhage in preterm infants. It is not as sensitive as CT scan and is not the preferred imaging modality for assessing AHT. Educational objective: CT scan of the head is a fast and cost-effective method for detecting subdural hematomas in infants with abusive head trauma. References: Imaging abusive head trauma: why use both computed tomography and magnetic resonance imaging? (http://www.ncbi.nlm.nih.gov/pubmed/25501731)

A 9-Month-Old Boy Is Brought to the Emergency Department by His