• X-ray negative pneumonia
• Early or subacute endocarditis
• Early epidural abscess
• Early osteomyelitis
• Early necrotizing fasciitis
• If the patient clinically has pneumonia but the chest x-ray is negative, consider treating with antibiotics anyway because chest x-ray a 10 percent false negative rate.⁶ You do not need to confirm the diagnosis with CT.

For the remaining infectious diagnoses, the key is to do a thorough physical exam. Look for and document pertinent negatives and follow-up on any positives. You can defend a “miss” when you looked and there was no evidence of an infection in the skin (the more you can examine, the better), axilla, back, or feet, and no murmur or signs of peripheral embolization. You can’t defend it when you just write “WNL” (“Within Normal Limits,” sometimes derided as, “We did Not Look” or “We Never Looked”).

Pulmonary Embolism (PE)

Emergency physicians rarely miss PEs presenting with classic symptoms (chest pain or dyspnea). However, a significant percentage of PEs are present with tachycardia and no chest pain or dyspnea. Look for signs of DVT (present in 40 percent of patients with PE), and tachypnea (RR≥20).⁷ Consider further investigation if either is present. The respiratory rate obtained by the RN is not always reliable.⁸ In the setting of unexplained tachycardia, consider doing it yourself. Doing so will make your care more defendable even in the case a pulmonary embolus is later diagnosed.

Myocardial Infarction (MI)

Missed myocardial infractions are 7-55 percent of unexpected deaths after discharge from the emergency department.⁹ Silent MI is relatively uncommon in young patients and in patients with no risk factors, but more common in patients with diabetes mellitus and up to 15 percent in the elderly.¹⁰ Tachycardia, or alternately, high unexplained variability, can be the only sign of silent MI.¹¹

In elderly patients or patients with multiple cardiac risk factors and tachycardia where you have other explanation, consider an ECG, Troponin, and HEART Score. Be on the lookout for atypical symptoms such as extreme fatigue, acutely decreased exercise tolerance. Document the absence of typical and less typical coronary symptoms, and the absences of and S3 or S4 heart sound and JVD.

Acute Cardiomyopathy/Congestive Heart Failure

• Acute non-ischemic cardiomyopathy/myocarditis and undiagnosed congestive heart failure are underappreciated causes of sudden death after discharge but may be the cause in up to 10 percent.¹² We don’t miss the obvious cases, but subtle cases can escape and die later from lethal arrhythmias.
• Risk factors for acute cardiac pump dysfunction in patients not previously diagnosed include: S3, abdominojugular reflux, JVD, recent MI, crackles, paroxysmal nocturnal dyspnea, any murmur, and lower extremity edema. If any of these are present, a BNP may be warranted. Before you get the BNP result ascertain your clinical Gestalt for CHF—if it’s low and the BNP is also normal, the chances of CHF are very low.¹³

Other Considerations

For most conditions, a thorough physical exam is key: