Pre-Operative Assessment

Question 1

Evaluation of a difficult airway

Answer 1

LEMON

Look for difficulties to ventilation - Boots (beard, obesity, old, toothless, snoring/neck)

Evaluate - 3-2-1 rule

Mallampati score

Obstruction - stridor, foreign bodies

Neck mobility

Question 2

Airway assessment

Answer 2

■ Cervical spin stability and neck movement – upper cervical spine extension, lower cervical spine flexion (“sniffing position”)

■ Mallampati classification

■ “3-2-1 rule”
◆ thyromental distance (distance of lower mandible in midline from the mentum to the thyroid notch); <3 finger breadths (<6 cm) is associated with difficult intubation
◆ mouth opening (<2 finger breadths is associated with difficult intubation)
◆ anterior jaw subluxation (<1 finger breadth is associated with difficult intubation)

■ tongue size

■ dentition, dental appliances/prosthetic caps, existing chipped/loose teeth – pose aspiration risk if dislodged and must inform patients of rare possibility of damage

■ nasal passage patency (if planning nasotracheal intubation)

■ assess potential for difficult ventilation

Question 3

Mallampati scoring

Answer 3

I- full view of uvula (body and base)

II - full view of uvula and partial view of tonsillar pillars and tonsils

III - Base of uvula and post-pharyngeal wall

IV - Hard palate and tongue with other structures not visible

Question 4

Pre operative CBC indications

Answer 4

Major surgery requiring group and screen or cross and match; chronic cardiovascular, pulmonary, renal, or hepatic disease; malignancy; known or suspected anemia; bleeding diathesis or myelosuppression; patient >1 yr of age

Question 5

Pre operative indication sickle cell screen

Answer 5

Patients from geographic areas with high prevalence of sickle cell disease and/or genetically predisposed patients (hemoglobin electrophoresis if screen is positive)

Question 6

Pre operative indication INR, aPTT

Answer 6

Anticoagulant therapy, bleeding diathesis, liver disease

Question 7

Pre operative indication electrolytes and creatinine

Answer 7

Hypertension, renal disease, DM, pituitary or adrenal disease; vascular disease, digoxin, diuretic, or other drug therapies affecting electrolytes

Question 8

Pre operative indication fasting glucose level

Answer 8

DM (repeat on day of surgery)

Question 9

Pre operative indication pregnancy (beta hcg)

Answer 9

Women of reproductive age

Question 10

Pre operative indication ecg

Answer 10

Heart disease, DM, other risk factors for cardiac disease; subarachnoid or intracranial hemorrhage, cerebrovascular accident, head trauma

Question 11

Pre operative indication chest radiograph

Answer 11

Patients with new or worsening respiratory symptoms/signs

Question 12

Gross predictor used in overall outcome in anesthesia (not used as stratification for anesthetic risk aka mortality rates)

Answer 12

• ASA 1: a healthy, fit patient

• ASA 2: a patient with mild systemic disease
■ e.g. controlled Type 2 DM, controlled essential HTN, obesity, smoker

• ASA 3: a patient with severe systemic disease that limits activity
■ e.g stable CAD, COPD, DM, obesity

• ASA 4: a patient with incapacitating disease that is a constant threat to life
■ e.g. unstable CAD, renal failure, acute respiratory failure

• ASA 5: a moribund patient not expected to survive 24 h without surgery
■ e.g. ruptured abdominal aortic aneurysm (AAA), head trauma with increased ICP

• ASA 6: declared brain dead, a patient whose organs are being removed for donation purposes
• for emergency operations, add the letter E after classification (e.g. ASA 3E)