NMCLE key terms

The heart's ability to increase the force of contraction as ventricular filling (preload) rises, so that greater diastolic stretch produces a stronger systolic ejection within physiological limits.

The degree of ventricular stretch at the end of diastole, determined mainly by venous return and blood volume; it is the loading condition that governs stroke volume through the Frank-Starling relationship.

The volume of blood ejected by one ventricle per minute, calculated as stroke volume multiplied by heart rate; a key index of circulatory adequacy in shock, sepsis, and anesthesia.

The difference between measured serum sodium and the sum of chloride and bicarbonate, used to classify metabolic acidosis into high-gap causes such as ketoacidosis and lactic acidosis versus normal-gap causes such as diarrhea.

A primary fall in plasma bicarbonate with compensatory hyperventilation and reduced arterial carbon dioxide; causes are grouped by anion gap and by urinary ammonium excretion in the normal-gap forms.

The difference between measured and calculated serum osmolality; an elevated gap suggests unmeasured osmoles such as methanol, ethylene glycol, isopropanol, or mannitol in a poisoned or comatose patient.

Life-threatening organ dysfunction caused by a dysregulated host response to infection, with persisting hypotension requiring vasopressors and a raised lactate despite adequate fluid resuscitation.

An end product of anaerobic glucose metabolism; a raised blood level signals tissue hypoperfusion or impaired clearance and is used to grade severity and guide resuscitation in sepsis and shock.

A nonspecific clinical state marked by fever or hypothermia, tachycardia, tachypnea, and abnormal white cell count, which may arise from infection, pancreatitis, burns, or trauma.

A gene whose normal product restrains cell division or repairs DNA; loss of both alleles removes that brake and predisposes to cancer, as with RB in retinoblastoma and TP53 in many tumors.

A mutated or overexpressed gene that drives uncontrolled proliferation; examples include RAS mutations and BCR-ABL fusion, and their protein products are targets of specific inhibitor drugs.

The multistep process by which cumulative genetic and epigenetic changes transform a normal cell into an invasive cancer, typically passing through initiation, promotion, and progression phases.

Presystemic elimination of an orally absorbed drug by gut wall and liver before it reaches the systemic circulation, which reduces oral bioavailability and can be saturated at higher doses.

The fraction of an administered dose that reaches the systemic circulation unchanged; it is 100 percent by definition for intravenous dosing and lower for oral dosing because of incomplete absorption and first-pass loss.

The apparent volume relating the amount of drug in the body to its plasma concentration; a large value indicates extensive tissue uptake, while a small value suggests confinement to plasma.

The time taken for plasma drug concentration to fall by half during elimination; it determines dosing interval, time to steady state, and how long a drug persists after stopping.

The ratio of a drug dose producing toxicity to the dose producing the desired effect; a narrow index, as with digoxin, warfarin, and lithium, demands monitoring of levels and clinical status.

A coordinated program of prescribing practices that promotes appropriate agent, dose, route, and duration, reducing resistance selection, adverse effects, and cost without compromising outcomes.

The lowest concentration of an antimicrobial that prevents visible growth of a standardized bacterial inoculum; it guides susceptibility reporting and drug selection for the infecting organism.

Laboratory testing in which a specimen is cultured to identify a pathogen and then exposed to antimicrobials to determine which agents inhibit its growth, informing targeted therapy.

The period from delivery of the placenta until about six weeks postpartum, during which the uterus involutes and the risks of hemorrhage, infection, and thromboembolism are highest.

Blood loss exceeding 500 mL after vaginal birth or 1000 mL after cesarean, or any loss causing hemodynamic compromise; uterine atony is the commonest cause and is managed with uterotonics and massage.

New hypertension after 20 weeks of gestation with proteinuria or other maternal organ dysfunction; delivery is the definitive treatment and magnesium sulfate prevents eclamptic seizures.

A plotted position showing how a child's weight, length, or head circumference compares with a reference population of the same age and sex; serial crossing of centiles is more concerning than a single low value.

Inadequate physical growth in infancy or childhood, shown by weight falling across centiles or persistently below the expected range, with causes spanning undernutrition, chronic disease, and neglect.

A skill such as sitting, walking, or first words that most children acquire within a predictable age range; delay in one or more domains prompts screening for underlying disorders.

Indirect protection of unvaccinated individuals that arises when a sufficiently high proportion of a population is immune, interrupting chains of transmission of an infectious agent.

Incidence is the number of new cases arising in a population over a period; prevalence is the total number of existing cases at a point in time, reflecting both incidence and duration.

Sensitivity is the proportion of truly diseased people correctly identified by a test; specificity is the proportion of truly healthy people correctly classified as negative. Both are properties of the test, not the patient.

The probability that a person with a given test result truly has or lacks the disease; unlike sensitivity and specificity it changes with the prevalence of the condition in the tested population.

A condition that clinicians and laboratories are legally required to report to public health authorities, enabling surveillance, outbreak investigation, and control measures such as contact tracing.

A patient's voluntary agreement to an intervention after receiving and understanding information about its nature, purpose, risks, alternatives, and the consequences of refusal, given without coercion.

The professional duty to keep patient information private and disclose it only with consent or where law or overriding public interest requires, such as reporting certain infectious diseases.

A forensic determination of whether an accused person can understand the proceedings and instruct counsel; it concerns present capacity to participate, not guilt or mental state at the time of the offense.

Loss of function of one of the twelve cranial nerves, producing characteristic deficits such as ptosis and diplopia in third nerve palsy or facial asymmetry in seventh nerve palsy, which localize the lesion.

A loss of part of the normal field of vision, whose pattern helps localize damage along the visual pathway, from optic nerve lesions to chiasmal and retrochiasmal causes.

Reduced hearing caused by impaired transmission of sound through the external or middle ear, such as wax, effusion, or ossicular fixation, with air conduction worse than bone conduction on testing.