A 22-month-old white boy with no past significant medical history was transported to our tertiary care pediatric facility in respiratory failure.

Always remember you ABCDE's

Airway, Breathing, Circulation, and Disability/Neurological Status, Exposure

​

Rapid Evaluation

HPI:

A 22-month-old white boy with no past significant medical history was transported to our tertiary care pediatric facility in respiratory failure. The patient was in the waiting room of a dentist's office and was noted to be cyanotic. A call was made to Emergency Medical Services, and the child required intubation during transport. His parents stated that the patient had "cold symptoms" for 1 week prior to admission, but denied associated fever, vomiting, or diarrhea. There was no reported history of previous trauma or ingestion.

The patient was born full term. There is no history of previous hospitalizations or surgeries. Immunizations were not up-to-date. Development had been appropriate for age. The family denied recent travel or sick contacts. Medications present in the home were Tylenol, Motrin , and Klonapin .

Acute Respiratory Failure Differentials: THINK BROAD

Acute Respiratory Failure Differentials: THINK BROAD

• Congenital

• Anatomic

• Respiratory

• Infectious

• Trauma/Ingestion/Inhalation

• Cardiac

• Neurologic

• Other

Acute Respiratory Failure Differentials: THINK BROAD

Primary/Congenital: diaphragmatic hernia, pulm dysplasia,
Respiratory - RAD, Asthma exacerbation, pulmonary fibrosis, pulm hemorrhage
Anatomic: Vascular rings/slings., foreign body
Infectious - Pneumonia, bronchiolitis
Trauma/Ingestion- drowning, inhalation injury, toxin ingestion.
Cardiac - cardiac failure (how??), cardiac tamponade, arrhythmias, cor-pulmonale, cardiomyopathy
Neurologic - Anatomic / Traumatic (spinal cord, brainstem), status epilepticus, encephalitis, meningitis, hypoventilation syndrome, neuromuscular diorders,
Other Systems: Heme-pulmonary embolism, Onc-space occupying lesion, Child abuse

Vital signs: Rectal temperature 98.5° F, pulse 137, respiratory rate 19/min on a ventilator, blood pressure 93/71 mm/Hg, Spo2 99% on FiO2 40%, weight 12.3 kg.

General: Well nourished and well hydrated.

Cardiovascular: Regular rate and rhythm, systolic II/VI murmur

Respiratory: Lungs clear to auscultation bilaterally; orally intubated

Extremities: Warm to touch, well perfused, pulses good
Neurologic: Sedated, pupils 3 mm bilaterally, equal and reactive; strength 1/5, deep tendon reflexes were brisk

​Physical Exam

Acute Respiratory Failure Differentials: Narrow it Down

What are the top most likely differentials



why?

​Labs

CBCD: White count 14,200/mm³ with 37% granulocytes, 52% lymphocytes, 7% monocytes, 3% eosinophils, and 1% basophils; hemoglobin 11.7g/dL, hematocrit 34.6%, platelets 560/mm³

CRP: 1.9 mg/dL

CMP: Sodium 135 mEq/L, potassium 4.4 mEq/L, BUN 11g/dL, creatinine 0.3 mg/dL, bicarbonate 19 mEq/L, glucose 159mg/dL

Liver function test: normal

Comprehensive urine drug screen: positive for benzodiazepines (patient was given a benzodiazepine for intubation)

​Labs

Salicyclate and acetaminophen level: negative

Serum ethanol: negative

Arterial blood gas: 7.38/40.2/159/19/-1 ----> How do you interpret this?

Lactic acid: 0.8 micromol/L

Ammonia: 21 micromol/L

CSF studies: nucleated cell count 0/microliters, red blood cell count 170 (100% uncrenated), glucose 72 mg/dL, protein 27 mg/dL

Blood culture, CSF culture, respiratory viral culture, urine culture: no growth

Encephalitis panel: no growth

CT scan of brain: normal

EEG: normal

ECG: normal

​MRI: -->

Imaging

MRI of brain and brain stem: Chiari 1 malformation with no evidence of syrinx

Diagnosis

What is a Chiari Malformation?

Symptoms: recurrent headache, neck pain, urinary frequency, and progressive lower extremity spasticity.

Etiology: displacement of the cerebellar tonsils into the cervical canal.

​​Chiari 1

​Symptoms: progressive hydrocephalus and a myelomeningocele.

Etiology: Displacement of the inferior vermis, pons, and medulla into the cervical cana

Chiari 2

Herniation of the cerebellum and brainstem through a defect in the back of the skull

Chiari 3

Incomplete cerebellum

​​Chiari 4

...about our case

Shortly after arrival, the child became very active and agitated, reaching for his mother and trying to remove lines and tubes. A trial of extubation was attempted, but he quickly progressed to respiratory distress and was immediately re-intubated. Further pressure support trials were also unsuccessful.

​Chiari 1 Malformation- Resp Failure

brainstem compression via herniation OR secondary hydrocephalus leads to dysfunction of the reticular activating system.

Case Conclusion

Immediate: Acetazolamide, "Curative": Neurosurgical Intervention

The Neurosurgery department was consulted, and after reviewing the findings of the MRI report; they recommended starting the patient on Diamox (acetazolamide).

He was successfully extubated and was transferred to another facility, where he underwent corrective surgery for Chiari 1.

References

https://www.medscape.com/viewarticle/503897_7

https://emedicine.medscape.com/article/908172-workup

https://www.researchgate.net/figure/Chiari-III-and-IV-A-Cerebellum-in-encephalocele-B-Hypoplasia-of-cerebellum-and_fig3_323791588

https://www.ninds.nih.gov/health-information/disorders/chiari-malformations