ABS Surgical Critical Care flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Oxygen delivery formula

DO2 equals cardiac output multiplied by arterial oxygen content and 10. CaO2 = (1.34 x Hb x SaO2) + (0.0031 x PaO2). Normal DO2 ~500-600 mL/min/m2.

Oxygen consumption formula

VO2 = CO x (CaO2 - CvO2) x 10. Normal VO2 is ~110-160 mL/min/m2. Widened arteriovenous oxygen difference indicates increased extraction due to low output.

Sepsis-3 definition

Suspected infection plus an acute increase in SOFA score of at least 2 points. Septic shock adds vasopressor requirement for MAP >=65 and lactate >2 mmol/L despite adequate fluids.

Berlin ARDS criteria

Acute onset within 1 week, bilateral opacities not fully explained by effusion or collapse, PaO2/FiO2 <=300 with PEEP >=5 cmH2O, and respiratory failure not primarily cardiogenic.

Lung-protective ventilation

Tidal volume 6 mL/kg predicted body weight, plateau pressure <=30 cmH2O, and adequate PEEP. Reduces ventilator-induced lung injury and mortality in ARDS.

KDIGO AKI staging

Stage 1: creatinine rise >=0.3 mg/dL or 1.5-1.9x baseline. Stage 2: 2.0-2.9x. Stage 3: >=3x, creatinine >=4.0, or initiation of renal replacement therapy.

Cushing reflex

Hypertension with widened pulse pressure and bradycardia in response to elevated intracranial pressure. Signals impending herniation and requires urgent decompression.

Beck triad

Hypotension, distended neck veins, and muffled heart sounds in cardiac tamponade. Pulsus paradoxus and electrical alternans may also be present.

Parkland formula

4 mL x body weight in kg x percent total body surface area burned, given as lactated Ringer's. Half in first 8 hours from injury time, remainder over next 16 hours.

Rule of Nines

Adult burn surface estimate: each arm 9%, each leg 18%, anterior trunk 18%, posterior trunk 18%, head 9%, perineum 1%. Used to guide fluid resuscitation.

SIRS criteria

Temperature >38 or <36 C, heart rate >90, respiratory rate >20 or PaCO2 <32, and WBC >12,000 or <4,000 or >10% bands. Two or more define SIRS.

Trauma triad of death

Hypothermia, acidosis, and coagulopathy occurring together after severe injury. Each worsens the others, driving a spiral that requires damage control resuscitation.

Abdominal compartment syndrome

Sustained intra-abdominal pressure >20 mmHg with new organ dysfunction. Treated with decompressive laparotomy and temporary abdominal closure.

Revised Cardiac Risk Index

Six predictors: ischemic heart disease, heart failure, cerebrovascular disease, insulin-dependent diabetes, creatinine >2.0 mg/dL, and high-risk surgery. Each adds one point.

Malignant hyperthermia

Hypercarbia, muscle rigidity, and hyperthermia after volatile anesthetics or succinylcholine. Stop triggering agents and give dantrolene 2.5 mg/kg IV.

Anastomotic leak signs

Unexplained tachycardia, fever, ileus, abdominal pain, and rising lactate after surgery. CT with contrast is the diagnostic study of choice.

Acute mesenteric ischemia

Pain out of proportion to exam, often with metabolic acidosis and elevated lactate. CT angiography is diagnostic; early revascularization improves survival.

Postoperative atrial fibrillation

New atrial fibrillation after noncardiac surgery. Rate control first; anticoagulation guided by CHA2DS2-VASc and bleeding risk.

Delirium risk factors

Age >65, cognitive impairment, sensory deprivation, sleep disruption, immobility, pain, and polypharmacy. Nonpharmacologic prevention reduces incidence.

Alcohol withdrawal management

CIWA-Ar guides symptom-triggered therapy. Benzodiazepines are first-line; give thiamine before glucose in malnourished patients to prevent Wernicke encephalopathy.

PEEP physiology

Positive end-expiratory pressure recruits alveoli and reduces shunt, improving oxygenation. Excess PEEP causes barotrauma and reduces venous return and cardiac output.

Prone positioning

Placing ARDS patients prone for 12-16 hours daily improves mortality when PaO2/FiO2 is <150. Redistributes ventilation and reduces dorsal lung compression.

First-line septic shock vasopressor

Norepinephrine is first-line to maintain MAP >=65 mmHg. Vasopressin or epinephrine is added when MAP remains low despite norepinephrine.

Balanced crystalloid rationale

Balanced crystalloids reduce hyperchloremic metabolic acidosis compared with normal saline. Preferred for initial resuscitation in most critically ill patients.

Enteral nutrition timing

Start enteral feeding within 24-48 hours of ICU admission. Trophic feeds are acceptable if full feeds are not tolerated.

Sedation target

Target RASS -2 to 0 with daily interruption. Light sedation reduces ventilator days, ICU length of stay, and delirium incidence.

Glycemic control target

Target blood glucose 140-180 mg/dL in critically ill patients. Avoid hypoglycemia, which increases mortality.

Stress ulcer prophylaxis indication

Indicated with mechanical ventilation >48 hours or coagulopathy. Proton pump inhibitors or H2 blockers reduce gastrointestinal bleeding risk.

Damage control surgery

Abbreviated laparotomy with temporary closure, ICU resuscitation, then planned re-exploration. Used for trauma or severe physiologic derangement.

Intensivist-led staffing

High-intensity ICU staffing with dedicated intensivists reduces mortality and length of stay compared with low-intensity models.

Rapid response system

Early warning scores trigger bedside evaluation. Reduces cardiac arrests and unplanned ICU transfers outside the ICU.

ICU quality metrics

Tracked measures include ventilator-associated events, central line-associated bloodstream infections, catheter-associated UTIs, and delirium prevalence.