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ExAC: Patient Assessment and Risk Stratification: From ASA Class to Site of Care

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Patient Assessment and Risk Stratification: From ASA Class to Site of Care

This domain tests structured pre-procedure assessment, correct ASA physical status assignment, fasting rules, and matching the patient to the right site and depth of care. Items frequently ask you to classify a patient or decide whether a case is appropriate for a given setting.

ASA physical status

  • I: healthy. II: mild systemic disease. III: severe systemic disease. IV: constant threat to life. V: moribund. VI: brain-dead organ donor. The E suffix denotes emergency.
  • Assign the class reflecting the patient's current state, not the planned procedure. Uncomplicated obesity alone may be class II; obesity with OSA and poorly controlled hypertension is usually III.

Fasting and aspiration risk

  • Clear liquids 2 hours; breast milk 4 hours; infant formula, nonhuman milk and a light meal 6 hours; fatty or fried food and meat may require 8 hours.
  • Aspiration risk rises with obesity, pregnancy, gastroesophageal reflux, gastroparesis, bowel obstruction and emergency status. Sedation does not remove aspiration risk.

Risk tools

  • STOP-BANG of 3 or more suggests OSA risk: snoring, tiredness, observed apnea, hypertension, BMI, age, neck circumference, male sex.
  • The revised cardiac risk index includes ischemic heart disease, heart failure, cerebrovascular disease, insulin-treated diabetes, creatinine above 2 mg/dL, and high-risk surgery.
  • Frailty, functional capacity of at least 4 METs, and cognitive status shape both the plan and the disposition.

Worked example

A 60-year-old with BMI 40, STOP-BANG 5, CPAP use and hemoglobin A1c of 9 percent is scheduled for an elective 60-minute procedure. Reasoning: high risk for sedation-related respiratory events. Plan capnography, minimize opioids, ensure CPAP is available, choose a facility with postoperative monitoring, and optimize glycemic control before an elective case. If comorbidity is unstable, defer.

Traps that cost marks

  • Recording nothing by mouth since midnight without confirming what was actually consumed; a milky coffee is not a clear liquid.
  • Down-classifying ASA status to suit a facility's policy or billing.
  • Letting a risk score override clinical judgment in an obviously frail or unstable patient.
  • Failing to document baseline vital signs, cognitive status and a documented airway examination.