What Is Point-of-Care Testing?
Point-of-care testing (POCT) refers to diagnostic tests performed at the patient's side rather than in a hospital laboratory. In EMS, POCT provides immediate results that inform clinical decisions, guide treatment, and improve patient outcomes. As technology advances, EMS providers have access to an expanding array of portable diagnostic tools.
Common Point-of-Care Tests in EMS
Blood Glucose
Glucometry is the most widely used POCT in EMS. A finger-stick blood glucose reading takes seconds and immediately differentiates hypoglycemia from hyperglycemia, guides dextrose or insulin administration decisions, and helps identify diabetic emergencies. Always correlate the glucose reading with the patient's clinical presentation and symptoms.
12-Lead ECG
While not traditionally classified as POCT, the 12-lead ECG is a diagnostic test performed at the patient's side. It identifies ST-elevation myocardial infarction, cardiac dysrhythmias, and other electrical abnormalities. Prehospital 12-lead acquisition has reduced door-to-balloon times for STEMI patients by enabling cath lab activation before hospital arrival.
End-Tidal CO2 (EtCO2)
Capnography measures exhaled carbon dioxide and provides continuous data about ventilation status, perfusion, and metabolism. It confirms endotracheal tube placement, monitors CPR quality, detects respiratory depression, and can identify metabolic acidosis. Waveform capnography is increasingly considered standard of care in EMS.
Emerging POCT in EMS
- Troponin: Portable troponin assays can identify myocardial injury in the field, potentially guiding transport decisions
- Lactate: Handheld lactate analyzers help identify occult shock and sepsis
- iSTAT: Portable blood analyzers that measure basic metabolic panels, blood gases, and coagulation studies
- Portable ultrasound: Identifies pneumothorax, pericardial effusion, abdominal bleeding, and confirms endotracheal tube placement
Clinical Integration
POCT results should always be interpreted in the context of the patient's clinical presentation, history, and physical exam findings. A normal glucose reading does not rule out all causes of altered mental status. A negative troponin does not rule out acute coronary syndrome in the first few hours of symptom onset. Use POCT as one piece of the clinical puzzle, not as a definitive diagnosis.