1. Preoperative Assessment & Perioperative Management Ho-Sheng Lin, MD Associate Professor Department of Otolaryngology/ Head and Neck Surgery SCS Educational Day 11/27/07

2. Introduction

OSA is a multi-level upper airway disease

Positive Airway Pressure effective in relieving obstruction at all levels

Surgical Treatments (UPPP and BOT procedures)

• Address only specific segment of the upper airway

• Effective only if precise localization of the site of airway obstruction can be identified

3. Introduction

Failure to recognize the multi-level nature of airway obstruction may account for the poor surgical outcome following UPPP alone

Sher et al. (1996)

• Meta-analysis (n = 337 pts) - UPPP alone

• No selection for level of airway obstruction (Types I - III)

• • Response rate =40.7%

UPPP

• Discredited by many in the field of sleep medicine

• May not be a bad procedure

• Poor result due to misuse by Surgeons

Attempt to identify site(s) of obstruction and tailor surgical approach to address this obstruction resulted in improved outcome following surgery

4.

Riley and Powell (1986)

• Genioglossus advancement and hyoid myotomy (GAHM) - BOT

• Stanford Powell Riley Protocol (Response rate =76. 5 % , n=306)

• • Phase I:Select surgical procedures based on site of airway obstruction

• • • Response rate =60%

• • Phase II:Bimaxillary Advancement

• • • Response rate =95%

• Basis of modern surgical management of OSA

Powell Riley 2-Phase Surgical Protocol 66% GAHM BOT only Type III 60% UPPP and GAHM Palatal and BOT Type II 80% UPPP Palatal only Type I Response Rate Type of Surgical Procedure(s) Site of Obstruction Fujita Classification 5. Powell Riley 2-Phase Surgical Protocol 6. Powell Riley 2-Phase Surgical Protocol

Overall success =76.5% (234/306)

• Phase I surgery =61%cure rate (145/239)

• Phase II surgery =97%cure rate (89/91)

Cure rate =95%for pts who completed protocol

N=306 Phase ISurgeryN=239 Failed priorUPPPN=60 ResponderN=145 Nonresponder N=94 SkeletaldeformityN=7 Refusedfurther surg N=70 Proceed tophase II N=24 Phase II Surgery N=91 Responder N=89 Nonresponder N=2 7. Powell-Riley Phase I Soft Tissue

Riley and Powell reported Cure rate of 61%

Other investigators reported Cure rate ranging from 24 - 84%

Average of 56%

Sleep 2007; 30:461-7 8. Powell-Riley Phase I Soft Tissue

Good Phase I surgical result depend on precise localization of site of obstruction

Problem:Current Modalities to Identify Exact Sites of Airway Obstruction is Imprecise and Subjective

• Wide variation in surgical success rate( 24 - 84%)

• Less than perfect results following phase I surgery(56%)

9. Diagnostic Modalities

Current diagnostic modalities are inadequate

Limited by lack of accuracy, high cost, invasiveness

• General Head & Neck Exam

• • Assess size of tongue, tonsil, soft palate, OP airway

• • Modified Mullers Maneuver

• Lateral Cephalometric Analysis

• Fluoroscopy

• Pharyngeal Pressure Measure

• Sine-CT Scan and MRI

• Sleep Endoscopy

10.

Overall

• • Body mass index (BMI)

• • Neck circumference

• • Retrognathia facial profile

Nose and Nasopharynx

Oropharynx

• • Tonsil (1-4+)

• • Soft palate

• • Lateral pharyngeal wall

• • BOT

• • Oropharyngeal opening

Friedman Staging System

• • Tonsil size, BOT position, BMI

General Head & Neck Examination 11. General Head & Neck Examination

Oropharynx

• Tonsil (1-4+)

• Soft palate

• • Long, wide,

• • bifid, etc

• Lateralpharyngeal wall

• Oropharyngeal opening

• BOT (1-4+)

• • Mallampati

• • Friedman

12. General Head & Neck Examination

Oropharynx

• Performed with tongue inside mouth

• BOT (1-4+)

• • Mallampati

• • Friedman

13. Friedman Clinical Staging

Stage I

< 40 < 40 3, 4 3, 4 I II BMI Tonsil Size Friedman Tongue Position 14. Friedman Clinical Staging

Stage III

< 40 < 40 0, 1, 2 0, 1, 2 III IV BMI Tonsil Size Friedman Tongue Position 15. Friedman Clinical Staging

Stage II

< 40 < 40 0, 1, 2 3, 4 I, II III, IV BMI Tonsil Size Friedman Tongue Position 16. Friedman Clinical Staging

Stage IV

All patients with significant craniofacial or other anatomic deformities 40 0, 1, 2, 3, or 4 1, 2, 3, or 4 BMI Tonsil Size Friedman Tongue Position 17. Successful Treatment of OSAHS with UP3 % Successful Treatment Friedman et al. Otolaryngol Head Neck Surg 2003;129:611-21. 18. Distribution of Patients with OSAHS by Stage Percentage of Patients Friedman et al. Otolaryngol Head Neck Surg 2003;129:611-21. 19. Successful Treatment of OSAHS with UP3 vs. UP3 + TBRF % Successful Treatment * * * Different from UP3 only ( P< .001) Friedman et al. Otolaryngol Head Neck Surg 2003;129:611-21. 20. Modified Muller Maneuver

Attempt to duplicate negative pressure during sleep

Inspiration against closed nose and mouth

Sitting and supine positions

Identify amount of pharyngeal collapse at soft palate and BOT level

Drawbacks:

• Awake patient

• Effort dependent

• Interpretations may

• be subjective

21. Lateral Cephalometric Analysis SNB SNB < 72oSevere mandibular deficiencyBOT obstruction PNS-P > 40velopharyngeal obstruction PAS < 7 mmBOT obstruction MP-H> 20 BOT obstruction

Taken using standardized technique

• Sitting natural head position

• End-expiration phase

• Distance of 5 feet

Drawbacks:

• Awake patient

• Upright rather than supine

• 2-Dimensional

• Adynamic

22. Fluoroscopy and Somnofluoroscopy

Can be performed with PSG

Ingestion of barium contrast to coat lumen

Dynamic assessment of airway collapse

Visualization of propagation of obstruction

Drawbacks:

• 2-D representation

• Only a limited number of apnea events can be captured due to worry about excessive radiation exposure

23. Pharyngeal Pressure Measurement

Performed at time of sleep study

2.3 mm Catheter w/ microtip pressure sensors

• Nasopharynx (above uvula)

• Oropharynx (between uvula and BOT)

• Hypopharynx (below BOT)

Level of airway collapse determined by changes in pressure patterns

If a portion of airway collapse, sensor proximal to the obstruction becomes silent

Drawbacks

• May alter sleep architecture

• Able to detect only the lowest site of airway obstruction

• Stenting of airway by catheter

• Precise localization of obstruction depends upon number of pressure sensors

24. Cine CT Scan

Can be combined with PSG

Capable of scanning entire airway from nasopharynx to larynx (8 cm) in 0.24 seconds

Allow analysis of entire airway during inspiration, expiration, and apneic episodes

Accurately localize the level of obstruction during apneic episodes

Drawbacks

• High cost

• Weight limitations

• Ionizing radiation

• Limited to axial plane

25. MRI

Excellent soft tissue anatomy

Multiple planes

No ionizing radiation

Drawbacks

• High Cost

• Weight limitations

• Noisy and may require sedation

• Claustrophobia

• Can not be combined w/ PSG

26. Sleep Endoscopy

Can be performed for surgical planning before or at the same time as the definitive procedure

Determine the site of airway obstruction / collapse during simulated natural sleep state (induced w/ low dose propofol)

Drawbacks

• Use of sedation may not completely simulate natural sleep

• Expensive and time consuming (if performed as part of surgical planning separately from surgical Tx)

• Stenting of airway by endoscope

27. Palatal Level:Posterior Collapse of Soft Palate 28. Palatal Level: Circumferential Narrowing 29. Oropharyngeal Level :Posterior Collapse of BOT 30. Oropharyngeal Level :Collapse of Lateral OP Wall 31. Oropharyngeal Level:Circumferential Narrowing 32. Supraglottic Level: Collapse of Epiglottis 33. Summary

Precise localization of the site(s) of airway obstruction is crucial for surgical success

Current diagnostic modalities are inadequate

• May account for the less than perfect results following phase I surgery(54%)

• Validate our current existing diagnostic modalities

• Identify new and better diagnostic modalities for localization of upper airway obstruction

• Standardization of diagnostic modalities in order to evaluate and assess effectiveness of surgical procedures

34. Preoperative Considerations: Selection of Surgical Candidates

Reason for surgical consideration

• • Failed Tx w/ PAP

• • Noncompliant w/ PAP

• • Desire surgical Tx despite good result using PAP

Weigh carefully the benefit to risk ratio

• Chance of surgical cure depends on:

• • Severity of OSA (Inferior result if RDI > 60)

• • Body mass index (Inferior result if BMI > 35)

• • Site of airway obstruction (Inferior result if large BOT)

• Comorbidities and surgical risks

35. Preoperative Considerations

Antibiotics

• Ancef 1 g and Flagyl 500 mg x 1

• If PCN allergic, Clinda 600 mg iv

Do not sedate patients preop

Decadron 10-16 mg iv prior to surgery

Discuss w/ anesthesia about difficult intubation

36. Intraoperative Considerations

Plan for difficult intubation

Toradol 30 mg IV (if < 65 yo) or 15 mg IV (if > 65 yo or weight < 110 lbs.)

• Given over 30 sec x 1

• Cautious use in pts w/ h/o CAD, COPD, Asthma, peptic ulcers, bleeding tendency

Decadron 10-16 mg iv at end of surgery

Extubate only when patient is completely awake

37. Postoperative Considerations

Obstruction may get worse after surgery due to

• Postop edema/swelling

• Residual anesthetics

• Use of postop pain medication

Low threshold to admit to ICU

Diet-clear to soft

Respiratory

• Patient must use CPAP/BiPAP when sleeping

• Call HO if patient refuse to wear CPAP

Keep SBP < 140 and diastolic BP < 90

38.

Pain meds

• Toradol 30 mg IV Q6 hours or 15 mg IV (if >65 yo or wt < 110lbs) given over 30 sec (standing order) x 3 days

• Tylenol with codeine elixir (120mg/12mg/5cc) 20-40 cc Q 4hrs prn

• 2% Viscuous lidocaine 15 cc gargle and spit Q4 hrs prn

• Morphine sulfate 2-4 mg iv Q 2hrs prn

Antibiotics

Decadron 10-18 mg iv Q6 hour

Peridex oral rinse 15 cc swish and spit Q6 hrs prn

Zantac 50mg iv Q6 hours

Postoperative Considerations