ABPS Emergency Medicine (BCEM) key terms

A state of inadequate tissue perfusion in which oxygen delivery fails to meet metabolic demand, producing cellular dysfunction and, if uncorrected, organ failure and death. It may occur with normal, low, or high blood pressure.

The percentage decline in blood lactate over time during resuscitation, used as a marker of improved perfusion and treatment response. Failure to clear suggests ongoing hypoperfusion or an unresolved source such as sepsis or bowel ischemia.

A bedside framework defining sepsis as life-threatening organ dysfunction from dysregulated host response to infection, operationalized as a rise in the Sequential Organ Failure Assessment score of at least two points.

Sepsis with persisting hypotension requiring vasopressors to maintain mean arterial pressure at or above 65 mmHg and a serum lactate above 2 mmol/L despite adequate fluid resuscitation.

A rapid bedside screen for poor outcome in suspected infection using three items: respiratory rate of 22 or more, altered mentation, and systolic blood pressure of 100 mmHg or less. Two or more positive items prompt escalation of care.

A predominantly alpha-adrenergic vasopressor that is first-line for most forms of vasodilatory shock. It raises mean arterial pressure while causing less tachyarrhythmia than dopamine and is typically titrated to a MAP target near 65 mmHg.

Clinician-performed bedside sonography used to answer focused questions rapidly, such as detecting pericardial effusion, assessing ventricular function, evaluating the inferior vena cava, or identifying free abdominal fluid during resuscitation.

A focused bedside ultrasound survey for free fluid in the pericardial sac and dependent abdominal and pelvic spaces, used to rapidly identify hemoperitoneum or tamponade in the unstable trauma patient.

Compression of the heart by accumulating pericardial fluid, impairing diastolic filling and reducing cardiac output. Classic findings include hypotension, distended neck veins, muffled heart sounds, and echocardiographic right ventricular collapse.

An exaggerated fall in systolic blood pressure during inspiration, conventionally greater than 10 mmHg, reflecting impaired right heart filling under constraint. It is classically associated with tamponade and severe obstructive airway disease.

Needle drainage of pericardial fluid, performed emergently for tamponade. Ultrasound guidance improves safety by confirming effusion, choosing a puncture site, and avoiding vital structures.

The coordinated administration of a sedative and a neuromuscular blocker in quick succession to secure the airway while minimizing aspiration risk. It includes preoxygenation, pretreatment of physiology, positioning, and a planned rescue strategy.

A drop in blood pressure around the time of intubation, driven by vasodilation from induction agents, loss of sympathetic tone, positive-pressure ventilation, and hypovolemia. It is associated with increased mortality and organ injury.

A structured sequence of rescue plans for failed oxygenation or failed intubation, progressing from optimized attempts through supraglottic rescue to surgical cricothyrotomy. It emphasizes limiting repeated attempts and declaring failure early.

An emergency front-of-neck airway created through the cricothyroid membrane, used as a final rescue when oxygenation cannot be achieved by less invasive means. It is a temporizing measure pending definitive airway management.

Continuous sedative and often analgesic therapy after endotracheal intubation to maintain comfort, prevent self-harm and device removal, and reduce dyssynchrony. Doses are titrated to a defined sedation target and reassessed regularly.

A spectrum of myocardial ischemia including unstable angina, non-ST-elevation myocardial infarction, and ST-elevation myocardial infarction. Diagnosis integrates symptoms, serial troponin, and electrocardiographic changes.

Acute coronary occlusion producing ST-segment elevation meeting defined criteria in contiguous leads, or an equivalent pattern. It mandates urgent reperfusion, with primary percutaneous coronary intervention preferred when available within target times.

A cardiac biomarker assay detecting very low troponin concentrations, allowing rapid rule-out and rule-in protocols for myocardial infarction. Serial sampling and change values, interpreted with clinical context, distinguish acute injury from chronic elevation.

Mechanical reperfusion of an occluded coronary artery by balloon angioplasty with or without stenting, the preferred treatment for ST-elevation myocardial infarction when it can be delivered promptly by an experienced team.

Pharmacologic dissolution of an acute coronary thrombus, used for ST-elevation myocardial infarction when timely percutaneous intervention is unavailable and there are no contraindications. Bleeding, especially intracranial hemorrhage, is the major risk.

A tear in the aortic intima allowing blood to track within the media, creating a false lumen. It presents with abrupt severe pain and may cause pulse deficits, aortic regurgitation, or malperfusion; proximal dissection requires urgent surgery.

Obstruction of pulmonary arteries, usually by thrombus from deep veins, impairing gas exchange and right ventricular function. Presentation ranges from dyspnea to obstructive shock, and risk-stratified pathways guide testing and treatment.

Echocardiographic or electrocardiographic evidence that the right ventricle is pressure-overloaded, such as septal flattening, right ventricular dilation, or T-wave inversion in right precordial leads. In pulmonary embolism it signals higher risk.

A validated clinical prediction rule that estimates pretest probability of deep vein thrombosis or pulmonary embolism from history, examination, and likelihood of an alternative diagnosis, guiding whether to test, image, or empirically treat.

A fibrin degradation product with high sensitivity but low specificity for venous thromboembolism. A negative result in a low- or intermediate-probability patient can exclude the diagnosis, while a positive result requires imaging.

Administration of a fibrinolytic agent to dissolve acute thrombus, used in massive pulmonary embolism with hemodynamic instability and in selected acute ischemic stroke within a time window. Major bleeding is the principal hazard.

Sudden focal neurologic deficit caused by arterial occlusion in the brain, producing an irreversibly injured core surrounded by salvageable penumbra. Time-critical reperfusion aims to limit final infarct size and disability.

Proximal intracranial arterial blockage, such as of the internal carotid or middle cerebral artery, producing severe deficits. It may benefit from mechanical thrombectomy, often beyond standard thrombolysis windows when imaging shows salvageable tissue.

The interval from emergency department arrival to start of thrombolytic infusion in acute ischemic stroke, used as a quality metric because shorter times improve outcomes.

A prolonged seizure or repeated seizures without recovery between them, operationally defined as lasting five minutes or more, requiring immediate benzodiazepine therapy and a staged escalation of antiseizure medications.

A class of drugs that enhance gamma-aminobutyric acid activity, producing sedation, anxiolysis, and anticonvulsant effects. In emergencies they are first-line for status epilepticus and are used for procedural sedation, with respiratory depression as a key risk.

Administration of sedative and analgesic agents to facilitate a painful or anxiety-provoking procedure while maintaining airway reflexes and cardiorespiratory stability. It requires monitoring, rescue capability, and documented reassessment throughout.

A metabolic emergency of insulin deficiency with ketone accumulation and high-anion-gap metabolic acidosis, often with hyperglycemia, dehydration, and total-body potassium depletion. Treatment combines fluids, insulin, and careful potassium replacement.

The difference between measured cations and anions, calculated as sodium minus chloride and bicarbonate, used to classify metabolic acidosis and narrow the differential of unmeasured acids.

Elevated serum potassium that destabilizes cardiac membranes and can cause lethal dysrhythmias. Emergency treatment includes membrane stabilization with calcium, intracellular shifting, and definitive removal of potassium from the body.

A preplanned system for rapidly delivering balanced blood components in fixed ratios to a hemorrhaging patient, with the goals of restoring perfusion, correcting coagulopathy, and minimizing crystalloid use.

A resuscitation strategy that accepts a lower-than-normal blood pressure until hemorrhage is controlled, aiming to avoid dislodging clot and worsening bleeding. It is generally limited to penetrating trauma without traumatic brain injury.

An antifibrinolytic drug that blocks plasminogen activation, reducing bleeding in trauma and obstetric hemorrhage when given early. It is most effective within a few hours of injury and carries a low thrombotic risk.