Level 3 Sleep Study Utilization and Interpretation CSIM October 14, 2015 Dr. Nicole Drost
Disclosures I have no financial disclosures that would present a conflict of interest with this presentation
Objectives Review screening for sleep apnea Review the data obtained from Level 3 sleep study Evaluate the benefits and limitations of Level 3 study Interpret cases with Level 3 studies and treatment
Screening for sleep apnea
Why be interested in diagnosing and treating sleep apnea? 4% F and 9%M have clinically significant SDB <10-20% of patients with disease are diagnosed Hospitalization rates higher for untreated OSA Patient utilized 23-50% more medical resource Surgery: 8x higher risk of difficult intubation Increased risk of post-operative complications CPAP before surgery in severe OSA reduced postoperative complications
Prevalence Wisconsin Cohort NEJM 1993
Screening Methods
Can J Anesth; Jan 2010
Can J Anesth; Jan 2010
STOP: yes or no STOP-BANG S: Do you snore loudly, loud enough to be heard through a closed door? T: Do you feel tired or fatigued during the day almost every day? O: Has anyone observed you stop breathing in sleep? P: Do you have a history of high blood pressure with or without treatment? STOP-BANG Sensitivity of yes to 2 questions B: BMI >35kg/m 2 AHI STOP STOP-BANG A: Age > 50y > 5/h Mild 65% 83.6% N: Neck circumference > 40cm >15/h 74.3% 92.9% G: Gender - male Moderate >30/h Severe 79.3% 100%
Can J Anesth; Jan 2010
STOP-BANG 3 Mod-Sev OSA AHI>15 SN 93% 100% NPV 90% 100% Severe OSA AHI> 30 As score increases 0-2 to 7-8 Probability of Mod-Sev OSA increases from 18-60% Probability of Severe OSA increases from 4-38% Low risk 0-2; High risk 5-8; Intermediate 3-4 CHEST 2015, (): doi:10.1378/chest.15-0903. Chung et al
CHEST 2015, (): doi:10.1378/chest.15-0903. Chung et al
CHEST 2015, (): doi:10.1378/chest.15-0903. Chung et al
STOP-BANG 3-4 1. STOP score 2 + BMI >35 Specificity AHI>15 rises 85% 2. STOP score 2 + neck circumference >40cm(16in) Specificity AHI>15 rises 79% 3. STOP score 2 + male gender Specificity AHI>15 rises 77% CHEST 2015, (): doi:10.1378/chest.15-0903. Chung et al
STOP-BANG and serum HCO3 STOP-BANG 3 Mod-Sev OSA SP 30% SP 82% Severe OSA SP 28% SP 80% STOP-BANG 3 + shco3 28 CHEST 2015, (): doi:10.1378/chest.15-0903. Chung et al
Level 3 Polysomnography
American Acadamy of Sleep Medicine PM are recommended for diagnosis of OSA in patients with high pretest likelihood of moderate to severe OSA PM not recommended for patients with major comorbid conditions Congestive Heart Failure Moderate-Severe Pulmonary Disease Neuromuscular disease Suspected comorbid sleep disorder PM may be indicated for patients whom in-lab PSG is not available (immobility, safety, critical illness)
AHI 5 AHI 10 AHI 15 AHI 30
Case Studies
Case 1 42yo female; BMI 54 Post op gyne procedure, desats after extubated and witnessed apnea Hx: snoring, tired, lives alone(no witnessed apnea at home) STOP-BANG score?
Case 2 78yo male RA, Cspine injury anterior cervical decompression and fixation following C5,6 and 7 trauma mowing lawn and fell off rocky cliff Snoring prior, worse after injury witnessed apnea BMI 22.5
STOP-BANG score?
Trialed on Auto CPAP Significant residual AHI; why? Options?
Case 3 68yo male ex smoker referred with COPD?: FEV1 69%, FVC 77%, ratio 69% (N DLCO/RV/TLC) BMI 36.9; neck circumference 22 in HTN Snores-wife sleeps in another room, Tired-naps every afternoon; ESS 5; Witnessed apnea
STOP-BANG
Thoughts?
Case 4 65yo female referred with nocturnal cough Neck circumference 14.5in HTN, snores, snorts awake at night, witnessed apnea Wt 101.8kg, BMI 36
STOP-BANG
Case 5 51yo male referred with COPD Ex smoker 25y x 1.5ppd Paralyzed R hemidiaphragm from stab wound CHF dx 2013: ECHO Diastolic dysfunction, EF50%, RV enlarged and mod RV impaired MEDS: Ventolin, Atrovent, Lasix, Ramipril, ECASA CT chest: mild emphysema, elevated R diaphragm, dilated main PA BMI 35 Severe COPD: FEV1 1.25(31%), FVC 2.68(54%), ratio 44, DLCO 69%, RV 182%, TLC 100%
STOP-BANG
Summary Sleep apnea is very common and undiagnosed in the majority of patients STOP-BANG is an easy screening tool Score 0-2 confidently excludes significant apnea Score 5-8 good SN for mod-sev OSA Level 3 polysomnography is reliable and easy to use in patients with a moderate-high pretest probability of sleep apnea and absence of significant co-morbid disorders Consider Level 1 study in patients with significant comorbid disease, negative level 3 study with symptoms, or incomplete/inadequate treatment response