Evaluating a Case of Sleep Apnoea Dr J.M. Joshi Professor and Head Department of Pulmonary Medicine T.N. Medical College B.Y.L. Nair Hospital Mumbai

SAS Sleep apnoea syndromes (SAS) represent a group of conditions with abnormal respiration during sleep 3 forms of sleep apnea: OSA, CompSAS and CSA constitute 84% 15% and 0.4%, of cases respectively Obstructive sleep apnea syndrome-OSAS (objective sleeping respiratory disturbance with daytime sleepiness) Nasal continuous positive airway pressure (CPAP) is the most effective treatment for patients with moderate to severe OSAS

Obstructive Apnoea Obstructive Apnoea when complete closure of the upper airway The respiratory efforts continue airflow chest abdomen

Central Apnoea Central Apnoea complete cessation of effort to breathe Airway still open but no respiratory drive, hence no respiratory muscle activity airflow chest abdomen

CLINICAL FEATURES Snoring is the cardinal symptom, cyclical with periods of loud snoring exceeding 100 decibels or snoring alternating with quieter intervals of apnoeas

Diagnosis of OSA A) EDS B) 2 of the following Snoring Witnessed apnoeas Unrefreshing sleep Daytime fatigue Poor concentration And c) Sleep Study showing AHI > 5 Ref: PSG Task Force, ASDA. Sleep 1997;20:

Polysomnography (PSG) Neurological EEG EOG EMG Cardio-Respiratory Snoring Thoraco-abdominal movements Airflow Oximetry Type 3 Type 4 Ref: Clinical guidelines for unattended PM in the diagnosis of OSA in adult patients. J Clin Sleep Med 2007; 3:737–747 Type 1,2

PSG Before and After CPAP

Severity Grading of OSAS Mild: 5–15 events/hour of sleep Moderate: 15–30 events/hour of sleep and Severe: more than 30 events/hour of sleep

Conventional Diagnostic Therapeutic Approach Full polysomnography (PSG) is currently the “gold standard’’ for the diagnosis of OSAS and titration of effective continuous positive airway pressure (CPAP) Technicians should titrate CPAP pressures overnight until most of the apnoeas and arousals are abolished, as monitored by PSG

Alternative Ambulatory Diagnostic Therapeutic Approach Urgent need to evaluate approaches to management that did not unduly rely on sleep laboratory–based PSG studies led to Diagnostic-therapeutic approach using home based limited PSG (cardio-respiratory variables only) or oximetry with ambulatory CPAP titration

Clinical Probability of OSAS Ambulatory diagnostic-therapeutic approach requires accurate identification of probable cases of OSAS Sleepy snorer by Epworth Sleepiness Score Sleep Apnea Clinical Score (SACS) based on snoring, witnessed episodes of apnea, neck circumference, and systemic hypertension

Epworth Sleepiness Score

Clinical Probability of OSAS “Sleepy Snorer” by Epworth Sleepiness Score Sleep Apnea Clinical Score (SACS) Ref: Likelihood ratios for a sleep apnea clinical prediction rule. AJRCCM 1994;150:

Summary Magnitude of OSA and paucity of sleep labs needs simplified approaches for physicians Enough evidence now exists that simple ambulatory diagnostic–therapeutic strategies have equivalent clinical outcome in cases with high pretest probability Patients who have a low probability, have co- morbidities or have difficulties during ambulatory management should be referred to a sleep centre for detailed evaluation/in-laboratory attended full PSG and further management