Adapted from Rosens, chp 16. 

Testing to consider in an elderly patient with altered mental status
ABG: hypoxia, CO2 retention, SOB
BMP/CMP: electrolyte abnormalities, hepatic encephalopathy
UA: infection, DKA, ingestion
PT/INT: hemorrhage, anemia, hypercoagulable
Lactate: ketotic state, ingestion, ischemia
TSH: thyroid storm, hypothyroid
Cardiac Enzymes: MI, ischemia, cardiogenic shock
CXR: infection, pneumothorax, CHF
CT head: hemorrhage, mass
MRI: edema, mass, ischemia
CTA: pulmonary emboli, aortic dissection
LP/CSF: infection, ICP

Dizziness can be difficult to assess in the ED given the vast range of etiologies and varying ways patients interpret their symptoms. Additionally, not all patients with emergency conditions will present with obvious focal deficits. A clinical decision making rule (HINTS) can help to more rapidly identify stroke patients to initiate acute therapies faster. The HINTS rule outperforms ABCD2  for stroke diagnosis in the ED when performed by qualified practitioners in patients with Acute Vestibular Syndrome. 

A mechanism to risk stratify patients presenting with syncope
The SFSR is criticized as being unsafe given a high miss rate (pooled sensitivity of 86%). Notably, there is one patient in the original trial who was SFSR negative and subsequently died (cardiac arrest after inpatient hospital discharge).

Exclusion Criteria

• Trauma-related loss of consciousness
• Alcohol-related loss of consciousness
• Drug-related loss of consciousness
• Definite seizure
• LOC associated with an altered level of consciousness or persistent new neurologic deficits did not meet operational definition of syncope and were excluded