ABS Surgical Critical Care key terms

The total volume of oxygen transported to the tissues per minute, calculated as cardiac output multiplied by arterial oxygen content. It sets the ceiling on aerobic metabolism and is compared with oxygen consumption to assess adequacy of resuscitation.

The rate at which tissues extract and use oxygen per minute. When supply falls below demand, extraction rises and anaerobic metabolism begins; a falling VO2 with rising lactate suggests inadequate perfusion rather than resolved demand.

Oxygen saturation of blood in the pulmonary artery, reflecting the balance between whole-body oxygen delivery and consumption. Low values suggest inadequate delivery or increased demand; unusually high values may indicate impaired extraction or shunting.

Oxygen saturation sampled from a central venous catheter, used as a practical surrogate for mixed venous saturation. It trends slightly higher than pulmonary artery values and is used to guide early resuscitation of septic shock.

The decline in blood lactate concentration over time during resuscitation. Failure to clear lactate indicates persistent tissue hypoperfusion or impaired hepatic metabolism and predicts worse outcome independent of vital signs.

A resuscitation strategy that accepts blood pressure below normal targets to limit bleeding and dilutional coagulopathy until hemorrhage is controlled. It is generally avoided in patients with traumatic brain injury or significant coronary disease.

An integrated approach to exsanguinating trauma combining early hemorrhage control, balanced blood product transfusion, limited crystalloid, and correction of coagulopathy, acidosis, and hypothermia before definitive repair.

The self-reinforcing combination of hypothermia, acidosis, and coagulopathy that drives exsanguination and death in severely injured or hemorrhaging patients. Each component worsens the others, so treatment must address all three simultaneously.

A predefined, protocolized system for rapidly delivering balanced blood components to a patient with life-threatening hemorrhage. It standardizes ratios, minimizes crystalloid, and coordinates laboratory and blood bank response.

An endogenous bleeding tendency that develops early after severe injury, driven by shock, tissue injury, hypoperfusion, and hyperfibrinolysis rather than dilution alone. It is identified by prolonged clotting times and treated with blood products and antifibrinolytics.

Organ dysfunction caused by sustained elevation of intra-abdominal pressure, typically above 20 mmHg with new organ failure. It impairs venous return, ventilation, and renal perfusion and is treated by decompression, often with laparotomy.

Sustained intra-abdominal pressure of 12 mmHg or greater, measured with the patient supine and the transducer leveled correctly. It is graded by severity and precedes abdominal compartment syndrome; treatment includes fluid moderation, sedation, and drainage.

Accumulation of air in the pleural space under positive pressure that collapses the lung and obstructs venous return. It is a clinical diagnosis requiring immediate needle or finger decompression followed by tube thoracostomy.

Acute hypoxemic respiratory failure with bilateral opacities not fully explained by cardiac failure, arising within days of a known insult. Management emphasizes lung-protective ventilation, prone positioning in severe cases, and conservative fluid strategy.

The difference between plateau pressure and applied positive end-expiratory pressure during mechanical ventilation. It reflects the cyclic stretch imposed on aerated lung and is associated with mortality in ARDS independent of tidal volume alone.

Airway pressure maintained at end-expiration during mechanical ventilation that recruits collapsed alveoli and prevents cyclic derecruitment. Excessive levels impair venous return and can overdistend compliant lung regions.

Incomplete exhalation causing progressive gas trapping and end-expiratory alveolar pressure above the set value. It is common in obstructive lung disease and high minute ventilation and can cause hypotension and barotrauma.

Placing a patient face down during mechanical ventilation to improve oxygenation and reduce mortality in moderate-to-severe ARDS. Benefits arise from more uniform lung stress distribution and recruitment of dorsal lung regions.

Life-threatening organ dysfunction caused by a dysregulated host response to infection. It is identified clinically by an acute rise in organ dysfunction scores in a patient with suspected infection and requires prompt antibiotics and source control.

Sepsis with persistent hypotension requiring vasopressors to maintain mean arterial pressure and with elevated lactate despite adequate fluid resuscitation. It carries high mortality and reflects profound circulatory and metabolic derangement.

The physical elimination of the focus of infection, such as drainage of an abscess, debridement of necrotic tissue, or removal of an infected device. Without it, antibiotics alone often fail in surgical sepsis.

A drug that raises vascular tone to restore perfusion pressure when hypotension persists despite adequate volume resuscitation. Choice depends on the shock state; norepinephrine is first-line for most distributive shock.

The likelihood that a patient's cardiac output will rise meaningfully with a fluid bolus, assessed by dynamic measures such as stroke volume variation or passive leg raise. Static pressures alone poorly predict it.

A rapidly progressive, often polymicrobial infection spreading along fascial planes with systemic toxicity and pain out of proportion to findings. It requires urgent wide surgical debridement and broad-spectrum antibiotics.

An abrupt decline in glomerular filtration, marked by rising creatinine or falling urine output. In surgical patients it commonly results from hypovolemia, sepsis, nephrotoxins, or abdominal hypertension and is managed by restoring perfusion and avoiding further injury.

Extracorporeal removal of solute and fluid used for refractory hyperkalemia, acidosis, volume overload, or uremic complications. Continuous modalities are preferred in hemodynamically unstable critically ill patients.

Delivery of nutrients into the gastrointestinal tract, preferred over parenteral routes when the gut works because it maintains mucosal integrity and reduces infectious complications. Early initiation within days of admission is generally favored in critical illness.

Potentially fatal shifts of electrolytes, especially hypophosphatemia, occurring when nutrition is reintroduced to a malnourished patient. Prevention relies on identifying high-risk patients and starting calories cautiously with electrolyte repletion.

An acute fluctuating disturbance of attention and awareness common in critically ill and postoperative patients. It is associated with longer ventilation and mortality and is managed by treating causes, mobilizing early, and minimizing sedating drugs.

Generalized muscle weakness developing during critical illness without another identifiable cause, often after prolonged ventilation and immobility. It prolongs weaning and rehabilitation and is mitigated by early mobilization and minimizing neuromuscular blockade and steroids.

A cluster of new or worsening physical, cognitive, and psychological impairments persisting after critical illness and ICU discharge. It affects survivors and families and drives interest in early mobility, delirium prevention, and follow-up care.

Pneumonia arising more than 48 hours after endotracheal intubation, favored by microaspiration around the tube cuff. Prevention includes head-of-bed elevation, oral care, sedation interruption, and early extubation.

A period of minimal ventilator support used to assess whether a patient can be liberated from mechanical ventilation. Passing it, together with adequate airway protection and cough, guides extubation decisions.

Coordinated administration of a sedative and neuromuscular blocker to secure the airway quickly while limiting aspiration risk. In critically ill patients it requires hemodynamic planning and anticipation of difficult laryngoscopy and post-intubation hypotension.

A bloodstream infection attributable to a central venous catheter in the absence of another source. Prevention bundles emphasize hand hygiene, full-barrier precautions, chlorhexidine skin antisepsis, and prompt removal of unnecessary lines.

Measures to prevent deep vein thrombosis and pulmonary embolism in immobilized or postoperative patients, using pharmacologic agents, mechanical devices, or both. Choice balances bleeding risk against thrombotic risk and is a core ICU safety metric.

The process of prioritizing patients for limited critical care resources based on likelihood of benefit, urgency, and available capacity. It is a core administrative responsibility of ICU leadership and must be applied consistently and transparently.

Operational decisions about admitting, transferring, and discharging critically ill patients to match demand with available beds, staffing, and equipment. It requires explicit criteria, surge planning, and communication across services.

A designated group that responds to bedside staff concern or abnormal vital signs outside the ICU to prevent deterioration and unplanned admission. Its effectiveness depends on clear activation criteria, culture, and leadership support.