Chapter 8: History, Physical Examination, and the Preoperative Evaluation

1. Chapter 8: History, Physical Examination, and the Preoperative Evaluation Ali Razfar MD 10-1-14

3. Gout: tophi of the pinna. Hard uric acid deposits under the skin that signify cartilage destruction.

5. Congenital cholesteatoma: TM intact, white mass usually in the anterior superior quadrant

7. Fordyce spots: sebaceous glands of the buccal mucosa.

9. Torus palatinus: benign bony outgrowth of the palate

11. Thornwaldt’s cyst

12. Preoperative Evaluation: Cardiovascular • Periop MI has 50% mortality • Risk factors JVD, 3rd heart sounds, recent MI within 6 months, nonsinus heart rhythm, frequent PVC (>5 per minute), age > 70 years, valvular AS, previous vascular or thoracic surgery, and poor overall medical status. • Patients are maintained on their antihypertensive, antianginal, and antiarrhythmic regimens up to the time of surgery

13. Patients with prosthetic valves, hx RF, endocarditis, congenital heart defects, MV prolapse with regurgitation should be abx prophylaxis as follows: • Low risk: 2 g amp 30 min before, 1 g 6 hours later • High risk: IV gent and IV amp, repeat dose 8 hours later

14. Respiratory • Patients with an arterial oxygen tension less than 60 mm Hg or an arterial carbon dioxide tension greater than 50 mm Hg are more likely to have postoperative pulmonary complications. • Spirometry: forced expiratory volume in 1 second/forced vital capacity ratio of less than 75% is considered abnormal, whereas a ratio of less than 50% carries a significant risk of perioperative pulmonary complications

15. Hematologic Disorders • Hemophilia A (Factor VIII:C) requires cryoprecipitate every 8 hours • Patients with type II von Willebrand’s disease should be transfused with cryo up to 24 hours before surgery with repeat infusion every 24 to 48 hours • Patients with type I will require an additional boost right before surgery • Type III management is similar to hemophilia A

16. Anticoagulants • Warfarin should be stopped at least 3 days prior to surgery • If very high risk for thromboembolism , can admit prior to surgery for heparinzation • Vitamin K can reverse warfarin in 6 hours, FFP much quicker • No strong evidence with ASA use and intraoperative bleeding, however most should stop at least 1 week before surgery

17. Chapter 9: General Considerations of Anesthesia and Management of the Difficult Airway

18. Patient Identification • Some predictors of anticipated difficulty with conventional DL: large overbite, large tongue, narrow mouth opening, or short chin • Still an incidence of 1-3% of unanticipated difficulty

21. Induction Agents and Volatile Anesthetics • Thiopental and propofol both have negative ionotropic effect • Etomidate more hemodynamically stable, but potential for adrenal suppression and myoclonic activity • Ketamine does not produce apnea, can be given IM but may have emergence delirium and sympathomimetic effect

22. Sedatives and Opioids • Opioids help blunt sympathetic response to laryngoscopy and intubation • Opioids work synergistically with benzos to depress respiratory drive • Opioids and benzos can be antagonized by naloxone and flumazenil, respectively

23. Paralytic Agents • Succinylcholine is a depolarizing agent occupies acetylcholine receptor prolonging refractory period • Can cause post-operative myalgia and transient increase in K levels • Fast acting, short duration • Most common muscle relaxant trigger of MH • Contraindicated in pts with increased intracranial pressure, increased intraocular pressure, elevated K • Non-depoloraizing agents like rocuronium prevent binding of Ach are longer acting and slower onset of action

24. Standard vs Rapid Sequence Induction • Preoperative fasting times: • 2 hours for clear liquids • 4 hours for breask milk • 6 hours for other food or beverage • RSI done for patients with increased risk of aspiration • No mask ventilation done • Paralytic agent given immediately, cricoid pressure held throughout • Proper preoxygenation allows apneic pt to maintain saturation during this minute

25. Formulation of Intraop and Post-op Plans • What is the surgical expectation at the end of the procedure? • If and when tracheostomy will be done? • MMF? • Procedure involves severe manipulation of airway/VCs? • Will patient positing cause airway edema? • Keep intubated vs exubation? If extubated, location? • What makes this patient a “difficult” airway? • Difficult mask vs difficult intubation? • Awake techniques needed?

26. Predictors of difficult MV • Grade 3 MV (inadequate, unstable, or requiring two providers): BMI >30, a beard, Mallampati 3 or 4, age > 57, limited jaw protrusion, and snoring. • Grade 4 MV (impossible to MV): Snoring and thyromental distance < 6cm • Grade 3 or 4 MV and difficult intubation: sleep apnea, BMI > 30, snoring, limited mandibular protrusion, and abnormal neck anatomy

28. Planning continued • Should intubation be awake, oral, nasal, or surgical? • What type of ETT will be used? • Smaller size necessary-MLT vs pediatric ETT? MLT is longer than standard ETT of same diameter, high-volume low pressure cuff. • RAE (Ring, Adair, and Elwyn or Right-Angled ETT): mandibles, T&A • Laser tube: tube is wrapped with a protective metal foil. Methylene blue-colored saline helps prevent fire in case of rupture • Armour tubes: resist kinking

34. Case 1 • 25 F with hx of hemangioma of tongue s/p numerous embolizations • 5 years earlier, procedure was canceled 2/2 inability to intubate orally or nasally. • Mouth opening 3 fingerbreadths, OC filled with hemangioma with extension into NP • Contemplating uterine surgery for fibroids? • Options?

35. Awake tracheostomy

36. Case 2 • 66 F, left VC polyp with ball-valving pedunculated polyp. On expiration, the polyp blocked airway in the OP. • Comorbidities: morbid obesity, asthma, emphysema, OSA, GERD

37. Awake nasal fiberoptic intubation

38. Case 3 • 36 F, evaluation for trismus and oral lesion biopsy • Unable to open mouth on exam, citing pain as the reason • No other co-morbidities

39. Awake nasal fiberoptic • Main issues: distinguishing between masseter muscle spasm/pain and TMJ limited opening • Minimizing post-op nausea in patients with difficulty opening mouth • Leaving bougie in place on extubation?

40. Case 4 • 41 F about to undergo lap chole • IV sedation with sodium pentothal. Inability to mask. • Oral airway placed with two-handed bag/mask ventilation, patient desat to 80s • Next step?

41. #4 LMA placed and ventilation established

42. Case 5 • 50 M about to undergo lumbar laminectomy. • PE 6’2”, 98 kg. Mallampati II, good mouth opening, poor dentition. Significant GERD so plan for RSI. Denies hx of difficult intubation. • After induction, MAC 4 and then Miller 3 fail to visualize larynx • Mask ventilation attempted but failed. • Code called, next step?

43. Anesthesiologist asked surgeon to perform cricothyrotomy • Surgeon “I haven’t done one in years” • Attempted jet ventilation with 18-guage needle resulting in significant bilaterally subQ emphysema • CPR initiated • Anesthesiologist then performs cric, 5-mm ETT passed • HNS arrives, bougie placed followed by intubation with 7.5 mm ETT • Prior records indicate that patient was difficult intubation

44. Case 6 • 35 M with Prader-Willi in OR for ventral hernia repair. • 4’11, 117 kg. Anesthesia not available. • Medical co-morbidities: OSA, GERD, asthma, seizure disorder, renal insufficiency • Small, thin nose. Mouth opening is 2 fingerbreadths. Mallampati Class IV. • Limited neck extension. Unable to lie flat. Prior emergent trach for bypass surgery

45. Awake nasal fiberoptic • Hollinger revealed entire glottic opening without difficulty. • Mac/Miller blade did not reveal the complete glottic opening. • Patient was left intubated overnight. • How would you extubate this patient?

46. Fire in the Hole!

47. Airway Fire • Steps to be taken in the event of an airway fire: • Stop flow of O2 to ETT and remove ETT • Flood field with fluids if needed • Mask ventilate with 100% O2 • Reintubate • Evaluate extent of injury with endoscopy

48. COCLIA • What is Ludwig’s angina?

49. Connective tissue infection of the FOM. It involves submandibular, sublingual, and submental spaces bilaterally • In one series, 75% of patients with ludwig’s angina required intubation or tracheotomy. In about 50%, intubation is unsuccessful resulting in emergent tracheotomy.

50. You are paged stat to the OR. Upon induction, the anesthesiologist has lost the airway.