08-12-2016, 11:06 AM
NBME Q
A 17-year-old boy is brought to the emergency department by ambulance 20 minutes after he was rescued from a pond into which he had fallen through ice. The exact duration of the patient's immersion is unknown but was at least 40 minutes. At the scene, the patient was pulseless and unresponsive; intravenous access was established, the patient was intubated, and cardiopulmonary resuscitation (CPR) was initiated. The patient received intravenous epinephrine twice en route to the emergency department. Medical history is unknown. On arrival, CPR is in progress. Rectal temperature is 28.0°C (82.4°F) and palpable systolic blood pressure is 50 mm Hg during chest compressions; the patient has no pulse or spontaneous respirations. Oxygen saturation is unobtainable. There is no evidence of head trauma. Pupils measure 5 to 6 mm bilaterally and are nonreactive. Gag, corneal, and oculocephalic reflexes are absent. Chest and abdominal examinations disclose no abnormalities. Neurologic examination discloses diffusely poor muscle tone, absence of deep tendon reflexes, and no Babinski sign. The cardiac monitor shows fine ventricular fibrillation. Results of STAT arterial blood gas analysis on FIO2 of 1.0 are shown:
PO2 50 mm Hg
PCO2 45 mm Hg
pH 6.90
Results of additional laboratory studies and chest x-ray are pending. Warmed intravenous fluids and gases are administered. The patient's parents arrive in the emergency department and request information regarding their son's status. Which of the following factors most strongly correlates with a favorable prognosis?
A) Arterial blood pH
B) Core temperature
C) Duration of cardiac arrest
D) Palpable systolic blood pressure during chest compressions
E) PO2 measurement
A 17-year-old boy is brought to the emergency department by ambulance 20 minutes after he was rescued from a pond into which he had fallen through ice. The exact duration of the patient's immersion is unknown but was at least 40 minutes. At the scene, the patient was pulseless and unresponsive; intravenous access was established, the patient was intubated, and cardiopulmonary resuscitation (CPR) was initiated. The patient received intravenous epinephrine twice en route to the emergency department. Medical history is unknown. On arrival, CPR is in progress. Rectal temperature is 28.0°C (82.4°F) and palpable systolic blood pressure is 50 mm Hg during chest compressions; the patient has no pulse or spontaneous respirations. Oxygen saturation is unobtainable. There is no evidence of head trauma. Pupils measure 5 to 6 mm bilaterally and are nonreactive. Gag, corneal, and oculocephalic reflexes are absent. Chest and abdominal examinations disclose no abnormalities. Neurologic examination discloses diffusely poor muscle tone, absence of deep tendon reflexes, and no Babinski sign. The cardiac monitor shows fine ventricular fibrillation. Results of STAT arterial blood gas analysis on FIO2 of 1.0 are shown:
PO2 50 mm Hg
PCO2 45 mm Hg
pH 6.90
Results of additional laboratory studies and chest x-ray are pending. Warmed intravenous fluids and gases are administered. The patient's parents arrive in the emergency department and request information regarding their son's status. Which of the following factors most strongly correlates with a favorable prognosis?
A) Arterial blood pH
B) Core temperature
C) Duration of cardiac arrest
D) Palpable systolic blood pressure during chest compressions
E) PO2 measurement