EDIC Part I key terms

A three-stage classification of acute kidney injury based on the rise in serum creatinine or the fall in urine output, used to grade severity and guide timing of renal replacement therapy.

A urine output below roughly 0.5 mL/kg per hour in an adult, sustained over several hours; a diagnostic criterion for acute kidney injury and a marker of renal hypoperfusion or obstruction.

A provocative loop diuretic challenge used to predict which patients with early acute kidney injury will progress to severe injury requiring renal replacement therapy; a brisk response suggests tubular function is preserved.

Extracorporeal removal of solute and fluid in kidney failure, delivered as intermittent haemodialysis, continuous modalities, or prolonged intermittent sessions; continuous therapy is preferred for haemodynamically unstable patients.

Regional anticoagulation of an extracorporeal circuit achieved by infusing citrate to chelate calcium at the filter, with calcium replaced systemically; requires monitoring for citrate accumulation and hypocalcaemia.

The plateau pressure minus positive end-expiratory pressure during controlled ventilation; a modifiable determinant of ventilator-induced lung injury that is targeted below roughly 15 cmH2O in ARDS.

The delivered breath size indexed to predicted rather than actual body weight; lung-protective ventilation aims for about 6 mL/kg predicted body weight in acute respiratory distress syndrome.

Placing a patient face-down for prolonged periods, typically 12 to 16 hours daily, to improve oxygenation and reduce mortality in moderate-to-severe acute respiratory distress syndrome.

A transient increase in airway pressure intended to reopen collapsed alveoli, followed by sufficient positive end-expiratory pressure to keep them open; evidence of benefit is limited and hyperinflation is a risk.

Delivery of heated, humidified oxygen at flows up to about 60 L/min through nasal cannulae, providing modest positive end-expiratory pressure and better comfort than a standard face mask.

Ventilatory support delivered through a mask or helmet rather than an artificial airway, used mainly for hypercapnic exacerbations of chronic obstructive pulmonary disease and cardiogenic pulmonary oedema.

Pharmacological paralysis, typically with a non-depolarising agent such as cisatracurium, used briefly in early severe acute respiratory distress syndrome or to facilitate procedures and targeted temperature management.

Peripheral nerve stimulation delivering four supramaximal impulses to quantify the depth of neuromuscular blockade and to confirm adequate recovery before extubation.

A modified gamma-cyclodextrin that encapsulates and inactivates rocuronium and vecuronium, allowing rapid reversal of even deep neuromuscular blockade.

The volume of blood ejected by the heart per minute, equal to stroke volume multiplied by heart rate; the central determinant of oxygen delivery and a key resuscitation target.

The percentage change in stroke volume across the respiratory cycle during controlled ventilation; a dynamic index of fluid responsiveness that is unreliable in spontaneous breathing, arrhythmia, or right ventricular failure.

A reversible autotransfusion manoeuvre that shifts venous blood from the legs to the thorax; a rise in cardiac output or stroke volume predicts responsiveness to a fluid bolus.

Derivation of cardiac output and related variables from the contour of the arterial pressure trace, calibrated or uncalibrated, used for continuous haemodynamic monitoring in critically ill patients.

The reciprocal of the absolute risk reduction; the number of patients who must receive an intervention for one additional patient to benefit.

A range of values around an estimate that is expected to contain the true population value with a stated probability, usually 95 percent; it conveys precision and supports interpretation of statistical significance.

Analysis of trial participants according to the group to which they were randomised, regardless of adherence; it preserves randomisation and gives a conservative estimate of efficacy.

The minimum number of patients whose outcome would need to change from non-event to event to make a statistically significant trial result non-significant; a small index signals a fragile finding.

A decision standard in which a surrogate chooses as the patient would have chosen, based on known values and preferences, rather than on the surrogate's own view of the patient's interests.

A decision standard used when a patient's wishes are unknown, in which the surrogate weighs benefits and burdens and chooses what a reasonable person would consider best.

A written or recorded statement made while a patient has capacity, specifying preferred treatments or appointing a decision-maker for a future period of incapacity.

A potentially fatal shift of phosphate, potassium, and magnesium into cells after reintroduction of nutrition in a malnourished patient, requiring cautious calorie escalation and electrolyte replacement.

Delivery of nutrients into the gastrointestinal tract by tube, preferred over the intravenous route when the gut works because it maintains mucosal integrity and reduces infectious complications.

Measurement of oxygen consumption and carbon dioxide production to calculate resting energy expenditure and respiratory quotient; the reference method for individualising calorie prescription in critical illness.

Clinically detected generalised muscle weakness arising during critical illness after other causes are excluded, associated with prolonged ventilation, sedation, and immobility, and with long-term functional impairment.

Progressive physical activity started within the first days of critical illness, ranging from passive movement to walking, intended to limit acquired weakness and shorten length of stay.

An acute fluctuating disturbance of attention and cognition common in critically ill patients, associated with longer ventilation, higher mortality, and later cognitive decline; non-pharmacological prevention is first-line.

Inadequate cortisol output relative to the stress of critical illness, considered when hypotension persists despite fluids and vasopressors; treated with hydrocortisone in refractory septic shock.

An oral glucose-lowering drug that also reduces heart failure hospitalisation and slows chronic kidney disease progression; in acute illness it carries a risk of euglycaemic ketoacidosis and is usually withheld.

A metabolic emergency of insulin deficiency with ketonaemia and metabolic acidosis, managed with fluid, intravenous insulin, and careful potassium replacement; total body potassium is depleted even when serum values are normal.

The ratio of observed to predicted deaths in a group, where prediction comes from a severity model; used to compare intensive care unit performance, with case-mix and calibration caveats.

Coordinated interventions to improve antibiotic prescribing by choosing the right agent, dose, route, and duration, thereby improving outcomes and limiting resistance and collateral harm.

Physical measures such as drainage, debridement, or device removal that eliminate the anatomical focus of infection; without it, antibiotics alone often fail in sepsis.

Controlled cooling or strict avoidance of fever after cardiac arrest or in acute brain injury, aiming to limit secondary neurological damage while preventing shivering and metabolic complications.

The pressure within the rigid skull, normally below about 15 mmHg in adults; sustained elevation reduces cerebral perfusion pressure and risks herniation.

Enhanced renal elimination of drugs seen in some critically ill, often younger patients with sepsis or trauma, which can cause subtherapeutic concentrations of renally cleared antibiotics unless doses are increased.

Measurement of drug concentrations in blood to individualise dosing, used for agents with narrow therapeutic windows or unpredictable pharmacokinetics such as aminoglycosides and vancomycin.

Sepsis with persistent hypotension requiring vasopressors to maintain mean arterial pressure and a raised lactate despite adequate fluid resuscitation, carrying high mortality.