Case Conclusion — Shock in the Emergency Department March 6, 2014
Posted by Andy Jagoda, MD in: Uncategorized , trackback
Recap of March’s Case: You are working in the ED late one evening when an 82-year-old man is brought in by his son. His son reports that earlier today, his father had been in his usual state of health, but this evening he found his father confused, with labored breathing. He is delirious and unable to answer questions. A focused physical examination demonstrates tachycardia without extra heart sounds or murmurs, right basilar crackles on lung auscultation, a benign abdomen, and 1+ lower extremity pitting edema. You establish intravenous access with a peripheral catheter and send basic labs. A further history obtained from the son reveals that his father has congestive heart failure with a low systolic ejection fraction, as well as a history of several prior myocardial infarctions that were treated with stent placement. As you consider this case, you ask yourself whether this patient is in shock, and if he is, what are the specific causative pathophysiologic mechanisms?
Case Conclusion: You rapidly determined that the patient was in shock. Although his blood pressure was within acceptable limits, he had clear clinical evidence of impaired end-organ perfusion as evidenced by altered mental status (impaired cerebral perfusion) and respiratory insufficiency. While you recognized the possibility of a cardiogenic process contributing to his presentation, the majority of the clinical data supported an infectious process (specifically, a right lower lobe pneumonia) resulting in a systemic inflammatory response and distributive pathophysiology due to septic shock. You administered a bolus of 30 mL/kg of lactated Ringer’s. You requested a comprehensive laboratory panel be sent, including CBC, chemistries and renal function analyses, arterial blood gas, serum lactate concentration, and blood cultures. You ordered a chest x-ray to better characterize his presumptive pneumonia. Because the patient was in shock due to sepsis, you ordered empiric broad-spectrum antibiotics based on your hospital’s antibiogram – in this case you elected to administer vancomycin 15 mg/kg (as the patient’s renal function is not yet known) and cefepime 2 gm IV. Despite these interventions, his blood pressure progressively decreased in the setting of an increasing temperature and worsening oxygenation. Given his clinical deterioration, you made the decision to intubate him and initiate mechanical ventilation with low-tidal-volume ventilation. Then, you placed a left subclavian central venous line and initiated a continuous infusion of norepinephrine, titrated for a MAP goal of > 65 mm Hg. His laboratory studies demonstrated leukocytosis (WBC 27 x 109/L), thrombocytopenia (90 x 109/L), acute renal failure (creatinine 3.1 mg/dL), and a lactic acidosis (lactate 7.2 mmol/L, bicarbonate concentration of 16 mmol/L, and base excess of -10 mEq/L). After receiving high-quality, evidence-based care in the ED, he was admitted to the MICU in critical condition, but ultimately made a full and uneventful recovery.
Thank you to everyone who participated in this month’s challenge!
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