NMLE Integrated key terms

The proportion of people who truly have a disease and are correctly identified as positive by a test. A highly sensitive test is useful for ruling out disease when the result is negative.

The proportion of people without the disease who are correctly identified as negative by a test. A highly specific test is useful for confirming disease when the result is positive.

The probability that a person with a positive test result actually has the disease. It depends on disease prevalence as well as on the test's sensitivity and specificity.

The number of patients who must receive a treatment for one additional patient to benefit, calculated as the reciprocal of the absolute risk reduction. Smaller values indicate a more effective intervention.

The arithmetic difference in event rates between a control group and a treated group. It reflects the true clinical impact of an intervention, unlike relative risk reduction, which can exaggerate small effects.

The apparent improvement in survival caused by earlier diagnosis without any real prolongation of life. Screening programmes are especially vulnerable to this distortion when survival is measured from diagnosis.

The overestimation of screening benefit caused by preferential detection of slowly progressive disease, which has a longer detectable preclinical phase. It makes screened patients appear to survive longer regardless of treatment.

Indirect protection of susceptible individuals that arises when a sufficiently large proportion of a population is immune, interrupting chains of transmission. The threshold depends on the pathogen's basic reproduction number.

The average number of secondary infections produced by one infectious case introduced into a fully susceptible population. It determines the herd immunity threshold and the intensity of control measures required.

A disease that clinicians and laboratories are legally required to report to public health authorities. Reporting enables outbreak detection, contact tracing, and national surveillance of disease trends.

The proportion of people diagnosed with a condition who die from it within a specified period. It measures severity rather than the overall burden of disease in a population.

The number of new cases of a disease arising in a defined population over a specified period. It reflects the risk of developing disease and is used to study causation and evaluate prevention.

The total number of existing cases of a disease in a population at a given time, expressed as a proportion. It reflects burden of illness and is influenced by both incidence and duration.

A patient's voluntary agreement to a medical intervention after receiving adequate information about its nature, risks, benefits, and alternatives, and after demonstrating decision-making capacity. It is both an ethical and a legal requirement.

A patient's ability to understand relevant information, appreciate the consequences of choices, reason about options, and communicate a consistent decision. Capacity is decision-specific and assessed clinically rather than by diagnosis alone.

A written statement made while a person has capacity, specifying preferences for future care or appointing a substitute decision-maker. It guides treatment when the patient later loses the ability to decide.

A legal duty for clinicians to disclose specified conditions, such as certain communicable diseases or suspected child abuse, to authorities, overriding ordinary confidentiality. The duty is defined by statute and varies by jurisdiction.

The ethical and legal obligation to protect patient information from unauthorized disclosure. It may be breached only with patient consent, when required by law, or when necessary to prevent serious harm.

A clinical judgement that an intervention cannot achieve its intended physiological goal or provide meaningful benefit. Recognising futility informs discussions about limiting non-beneficial treatment near the end of life.

Life-threatening organ dysfunction caused by a dysregulated host response to infection. It is identified clinically by a rise in the sequential organ failure assessment score and requires prompt antibiotics and source control.

Sepsis with persisting hypotension requiring vasopressors to maintain mean arterial pressure and a raised serum lactate despite adequate fluid resuscitation. It carries high mortality and demands urgent critical care.

A bedside screening score for sepsis 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 signal high risk.

A product of anaerobic metabolism measured in blood as a marker of tissue hypoperfusion. Elevated values in sepsis indicate severity and guide resuscitation, and clearance suggests improving perfusion.

The average arterial pressure across the cardiac cycle, approximated as one-third systolic plus two-thirds diastolic pressure. It is the target for vasopressor therapy because it drives organ perfusion.

Acute hypoxaemic respiratory failure with bilateral pulmonary infiltrates not fully explained by cardiac failure, arising within a week of a known insult. Management emphasises lung-protective ventilation and treatment of the cause.

The volume of air moved into or out of the lungs in one breath. In mechanical ventilation it is set by predicted body weight, with lower values reducing ventilator-induced lung injury.

Death of heart muscle caused by prolonged ischaemia, usually from coronary artery occlusion. Diagnosis requires a rise in cardiac troponin together with symptoms, electrocardiographic changes, or imaging evidence.

A cardiac muscle protein released into blood when myocytes are injured. High-sensitivity assays detect small elevations, so interpretation requires the clinical context and serial measurement.

An electrocardiographic finding of raised ST segments indicating transmural myocardial ischaemia. When present with typical symptoms it mandates urgent reperfusion by primary angioplasty or thrombolysis.

A clinical syndrome of breathlessness, fatigue, and fluid retention caused by impaired cardiac filling or output. It is classified by ejection fraction and managed with diuretics and disease-modifying drugs.

The proportion of ventricular end-diastolic volume ejected with each contraction, normally above 50 percent. Reduced values define heart failure with reduced ejection fraction and guide therapy.

A hyperglycaemic emergency with ketonaemia and metabolic acidosis, most often in type 1 diabetes. Treatment requires intravenous fluids, insulin infusion, and careful potassium replacement.

The difference between measured serum cations and anions, calculated as sodium minus chloride and bicarbonate. A raised gap indicates accumulation of unmeasured acids such as ketones or lactate.

A serum potassium concentration above the normal range, which risks fatal cardiac arrhythmia. Emergency treatment combines membrane stabilisation with calcium, intracellular shift, and potassium removal.

An abrupt decline in renal function marked by a rise in creatinine or fall in urine output. Causes are classified as prerenal, intrinsic renal, and postrenal, and management targets the underlying cause.

A pregnancy-specific disorder of new hypertension after 20 weeks' gestation with proteinuria or maternal organ dysfunction. Delivery is the definitive treatment, and magnesium sulphate prevents eclamptic seizures.

The occurrence of generalised seizures in a woman with preeclampsia, without another identifiable cause. It is a maternal emergency requiring airway support, magnesium sulphate, and delivery.

Haemolysis, elevated liver enzymes, and low platelets occurring in pregnancy, usually with preeclampsia. It threatens mother and fetus and often requires urgent delivery.

A drug used in obstetrics to prevent and treat eclamptic seizures and for fetal neuroprotection in preterm birth. Toxicity causes loss of reflexes and respiratory depression, monitored clinically and by serum levels.

Excessive bleeding after childbirth, conventionally more than 500 mL after vaginal or 1000 mL after caesarean delivery. Uterine atony is the commonest cause, and management follows a stepwise uterotonic and surgical approach.

Failure of the uterus to contract after delivery, the leading cause of postpartum haemorrhage. Risk factors include prolonged labour and multiple pregnancy, and treatment is uterine massage with uterotonic drugs.

Yellow discoloration of skin and sclera in a newborn due to raised bilirubin. It is common and usually physiological but may signal haemolysis, infection, or biliary obstruction requiring investigation and phototherapy.

Irreversible brain injury from bilirubin deposition in the basal ganglia of a jaundiced newborn. It causes lethargy, poor feeding, abnormal tone, and later neurological deficits, and is prevented by timely treatment of hyperbilirubinaemia.

Treatment of neonatal jaundice using light that converts bilirubin in the skin into water-soluble isomers excreted without conjugation. It reduces bilirubin and the risk of kernicterus.

A rapid assessment of a newborn at one and five minutes after birth, scoring heart rate, respiratory effort, muscle tone, reflex irritability, and colour. It describes condition and response to resuscitation but does not predict outcome.

A rapid, self-propagating change in membrane potential caused by sequential opening of ion channels. Its phases underlie nerve conduction, muscle contraction, and the electrical activity of the heart.

The principle that increasing ventricular filling stretches cardiac muscle and increases the force of contraction, within physiological limits. It explains how stroke volume rises with venous return.

The volume of plasma filtered by the kidneys per unit time, normally about 125 mL per minute. It is estimated from creatinine and used to stage chronic kidney disease and adjust drug dosing.

The total concentration of solute particles per litre of solution. Differences in osmolarity across membranes drive water movement and determine plasma tonicity and fluid shifts between compartments.

Circulatory failure caused by loss of intravascular volume, reducing venous return and cardiac output. It presents with tachycardia, hypotension, and cool peripheries and is treated with rapid fluid resuscitation and haemorrhage control.

Raised pressure within a closed fascial compartment that compromises perfusion and threatens muscle and nerve viability. Pain out of proportion and pain on passive stretch are early signs requiring urgent fasciotomy.

Thrombus formation in veins, manifesting as deep vein thrombosis or pulmonary embolism. Risk is assessed on admission and reduced with pharmacological or mechanical prophylaxis and early mobilisation.

Blockage of the intestinal lumen causing colicky pain, vomiting, distension, and absolute constipation. Management includes decompression, fluid and electrolyte replacement, and surgery when strangulation or failure of conservative care occurs.