PCCN (Adult) key terms

The average arterial pressure across one cardiac cycle, commonly estimated as diastolic pressure plus one-third of the pulse pressure. Below roughly 65 mm Hg, perfusion to the brain and kidneys is at risk.

Pressure in the superior vena cava or right atrium, used as a rough indicator of right-heart filling and volume tolerance. Trends and the response to a fluid challenge mean more than any single reading.

The oxygen saturation of blood in the pulmonary artery, showing the balance between oxygen delivery and tissue consumption. A fall below about 60 percent suggests delivery is failing to meet demand.

A product of anaerobic metabolism that rises when tissues receive too little oxygen or cannot use it. Serial values and the rate of clearance guide resuscitation and signal ongoing hypoperfusion.

Life-threatening organ dysfunction caused by a dysregulated response to infection. Clues include fever or hypothermia, tachycardia, tachypnea, altered mentation, low urine output, and rising lactate.

Sepsis with hypotension that persists after adequate fluid resuscitation and requires vasopressors, along with lactate above 2 mmol/L. It carries high mortality and demands rapid antibiotics and source control.

Sudden inflammatory lung injury producing bilateral opacities and severe hypoxemia that cardiac failure does not fully explain. Care centers on lung-protective ventilation, conservative fluids, and treating the underlying cause.

Pressure held in the airways at the end of expiration during mechanical ventilation, keeping alveoli open and improving oxygenation. Higher levels can reduce venous return and raise intrathoracic pressure.

A ventilator strategy using tidal volumes near 6 mL/kg of predicted body weight, plateau pressures of 30 cm H2O or less, and enough PEEP to avoid repetitive opening and closing of alveoli.

A ten-point scale from combative (positive 4) to unarousable (negative 5) that grades sedation depth. Most patients are targeted at light sedation so they can be assessed and participate in care.

A structured screen for delirium in critically ill patients, including those who are ventilated. It checks acute change, inattention, altered consciousness, and disorganized thinking.

A 3-to-15 score combining eye, verbal, and motor responses that quantifies level of consciousness. A decline of two or more points, particularly in the motor score, calls for urgent evaluation.

Deliberate control of body temperature, often 32 to 36 degrees Celsius, after cardiac arrest or for selected neurologic protection, followed by slow rewarming. Watch for shivering, bradycardia, electrolyte shifts, and skin injury.

A vasopressor that stimulates alpha receptors to raise vascular tone and mean arterial pressure, first-line for septic shock. It is given through a central line when possible, and extravasation can cause tissue necrosis.

Classification of sudden kidney function loss using serum creatinine rise and urine output. Stage 3 includes creatinine three times baseline, creatinine of 4 mg/dL or more, or anuria.

Slow, continuous extracorporeal clearance of fluid and solutes for hemodynamically unstable patients. Running over many hours avoids the rapid shifts of intermittent dialysis but requires anticoagulation and close monitoring.

Serum potassium above roughly 5.5 mmol/L that can trigger fatal dysrhythmias. Emergency care pairs intravenous calcium to stabilize heart membranes with insulin, albuterol, and removal by diuretics or dialysis.

A crisis of insulin deficiency causing hyperglycemia, ketone production, and anion-gap acidosis. Treatment is isotonic fluids, an insulin infusion, potassium replacement, and correction of the precipitating illness.

Five minutes or more of continuous seizure activity, or repeated seizures without regaining consciousness. Benzodiazepines come first, alongside airway support, glucose checks, and a search for the cause.

A planned, rapid delivery of red cells, plasma, and platelets in balanced ratios for life-threatening hemorrhage. Warming, calcium replacement, and frequent labs prevent hypothermia, hypocalcemia, and dilutional coagulopathy.

A set of practices for ventilated patients: head-of-bed elevation, daily sedation interruption with extubation readiness checks, oral care, and avoiding routine circuit changes. Together they lower pneumonia risk.

A primary bloodstream infection in a patient whose central line has been in place at least two days. Prevention includes hand hygiene, full-barrier insertion, chlorhexidine skin preparation, and daily line review.

Classification of localized tissue damage from sustained pressure, from nonblanchable erythema (stage 1) through full-thickness loss (stage 4), including injuries that cannot be staged. Staging guides treatment and prevention planning.

An observational scale scoring facial expression, body movement, muscle tension, and ventilator compliance to estimate pain in patients who cannot report it. Scores of 3 or higher usually prompt analgesia.

A document completed while a person has decision-making capacity that records treatment preferences or names a health care agent. It speaks for the patient once they can no longer do so.

A provider order stating that CPR will not be attempted if the patient has no pulse or stops breathing. It does not by itself limit other treatments, and comfort-focused care continues.

The process of explaining a procedure's purpose, risks, benefits, and alternatives so the patient can decide voluntarily. It requires capacity, allows questions, and can be withdrawn at any time.

The person legally authorized to make health care choices for a patient who lacks capacity, using the patient's known wishes first and best interest when wishes are unknown.

Acting to protect a patient's rights, preferences, and safety, including speaking up when a plan seems unsafe or inconsistent with the patient's goals.

The painful experience of knowing the right action but being blocked by hierarchy, policy, or conflicting values. Left unaddressed it contributes to burnout; ethics consultation and debriefing help.

A judgment that an intervention cannot achieve the patient's stated goal, such as recovery of meaningful neurologic function. Disagreements call for ethics consultation and careful communication, not unilateral withdrawal.

The duty to keep a patient's health information private and share it only with those who need it for care or legally required reporting. Breaches damage trust and carry legal consequences.

Ethical principles of acting for the patient's good and avoiding harm. In critical care they are weighed against autonomy and against treatments whose burdens outweigh likely benefit.

Transferring a task to another team member while keeping accountability for the patient's overall care. Nurses apply the five rights of delegation and confirm the delegate's scope and competence.

The defined escalation route from charge nurse to manager and beyond when a safety concern is not resolved. It lets nurses act on concerns without fear of retaliation.

An organizational approach that distinguishes human error from reckless behavior, encouraging staff to report mistakes while holding people accountable for unsafe choices. It supports learning after adverse events.

Offering family members the choice to remain at the bedside during CPR, with a staff member assigned to explain and support them. Evidence generally favors the option when policy allows.

A structured handoff covering situation, background, assessment, and recommendation. It helps a nurse convey urgency and a clear request when reporting a deteriorating patient.