1 MD, DA, DNB, Dip Diab.MD ,DCA, Dip software based statistics,Anaesthesia in OSAS Dr. S. Parthasarathy MD, DA, DNB, Dip Diab.MD ,DCA, Dip software based statistics, PhD (physiology)

2 History Dickens in pickwickian papers Shakespere all before thatIn 1966 , its official !! In adults, a typical night of sleep consists of four to six cycles of non-rapid eye movement (NREM) sleep followed by REM sleep. All muscle tone decrease except eye in REM

3 Definition of OSA cessation of airflow for more than 10 seconds despite continuing ventilatory effort five or more times per hour of sleep usually associated with a decrease in arterial oxygen saturation (SaO2) of more than 4%.

4 OSH Obstructive sleep hypopnea (OSH) is defined as a decrease in airflow of more than 50% for more than 10 seconds, 15 or more times per hour of sleep, and is usually associated with snoring and may be associated with decrease in SaO2 of greater than 4% Effort – OK No effort – central apnea

5 Associated with day time sleepiness – add syndromeIt has been estimated, that among t middle-aged 4% of men and 2% of women have clinically significant symptomatic OSA Per hour of sleep Mild AHI 10 – 15 Moderate AHI Severe AHI > 30 Associated with day time sleepiness – add syndrome

6 Etiology Down, treacher collins, shy drager syndromesHypothyroidism, androgen therapy , cushing Acromegaly Septal deviation ,adenoids and tonsils Laryngomalacia , tracheomalacia Stroke , head injury, facial injuries OBESITY

7 PATHOPHYSIOLOGY

8 Fat and obesity increases !!

9 Fat makes pharynx into AP axis and dilators ??

10 What happens ?? REM sleep Muscle relax Dilators don’t act wellNarrowing ↙ ↘ Turbulence – bernoulli effect Noise collapse ( obstruction )

11 What happens ?? With airway obstruction, -- SaO2 decreasesinspiratory efforts increase partial arousal from sleep and a sudden opening of airway. A short period of hyperventilation follows, until sleep deepens and airway obstruction recurs, repeating the cycle. The result is blood gas oscillation and sleep fragmentation.

12 Later ::?? repetitive airway obstructionarterial hypoxaemia, hypercarbia, polycythaemia, systemic hypertension, pulmonary hypertension, arrhythmias right ventricular failure. There is an increased incidence of heart disease, cerebrovascular events and sudden death.

13 Effects of sleep apnea

14 Clinical features Snoring – mild snorers can have severe diseasesChokes Nocturnal epilepsy Sweating Day time sleepiness Poor memory Headache on wake up Dry mouth Delirium Poor concentration Postgraduates !! ??

16 Investigations

17 Polysomnography – principle

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19 Treatment modalities Surgery CPAP, BiPAP AdenotonsillectomyNasal surgeries Uvulopalatopharyngoplasty Maxillofacial surgeries Mandibular advancement devices etc.. Previous ---tracheostomy Incidental surgery

20 Preanaesthetic evaluationSLAP, BANG Snoring, sleep study, SaO2, Lassitude, tiredness Apnea, Airway Pressure (SVR,PVR) Body mass index > 35, Bones Age >50, Arrhythmias Neck circum > 40 Gender – male Preanaesthetic evaluation Epworth Sleepiness Scale Berlin questionnaire

21 Undiagnosed disease – osasRisk areas All sedatives, narcotics worsen OSAS. Thoracic and upper abdominal surgeries Throat packs Nasal pack, nasogastric tube Supine position Undiagnosed disease – osas

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23 Implications All central depressant drugs diminish pharyngeal tone predisposing to upper airway collapse. Common anaesthetic drugs that have been shown to cause pharyngeal collapse include propofol, thiopentone, opiods,benzodiazepines,neuromuscular blockers and nitrous oxide.

24 Premedications No benzodiazepines Anti aspiration prophylaxis is okCPAP machine

25 Train the staff in the preop holding area and theatre staff CPAPWhat matters Severity of sleep apnea Type of surgery Postop care Train the staff in the preop holding area and theatre staff CPAP

26 Prefer Regional anesthesia Local anesthesia

27 General anesthesia Difficult airway – 5 % incidenceCant assess pharyngeal tissues Preop nasopharyngoscopy Maximal total body preoxygenation (filling of the alveolar, arterial, venous, and tissue spaces) requires that the patient breathe FIO2 = 1.0 for 3 minutes in a well sealed system

28 Oxygen insufflation into the pharynx via a small nasopharyngeal catheter during laryngoscopy of the obese patient may further delay the onset on arterial oxygen desaturation

29 RAMP

30 Take help – even mask holding

31 Monitors SaO2, ECG, NIBP, Capnography

32 GA IV glyco, dexa( 1 mg /Kg) , Induction RelaxantsReady for CICV IV glyco, dexa( 1 mg /Kg) , Induction Relaxants Intubation (oral RAE) Plan FOL in select cases Add RA for analgesia Retrograde

33 Submental and tracheostomy are other options

34 NIV, reintubation readyExtubation patient conscious, communicative, and breathing spontaneously with an adequate tidal volume and oxygenation. Extubation should be performed in the semi-upright or lateral position, after complete reversal of neuromuscular blockade. Airway exchange catheter !! NIV, reintubation ready

35 Extubation Post extubation obstruction 5 % incidenceNegative pressure pulmonary edema More in nasal surgeries with packing Difficult mask ventilation and tracheal intubation experience at the start the length and type of surgery, the severity of the OSA, Plan to keep the tube .

36 Be careful Extubate awake Responds meaningfully , purposefullyA dangerous mistake is to interpret mindless movement, such as reflex reaching for an endotracheal tube or suddenly trying to sit up, for purposeful movement.

37 HDU for seven days ?? During the first three days after surgery, pain scores are highest, resulting in increased analgesic requirements with an associated risk of respiratory depression. Reestablishment of sleep patterns occurs three to four days postoperatively, with the potential for a “REM rebound” and exacerbation of respiratory depression. Overall the ‘at risk’ period for patients with OSA may extend to one week post surgery.

38 Special about UPPP-- Tongue ??Preop CPAP (OSAS full) Awake FOL Need for a tracheostomy Keta + dexmed or suf + sevo Minimal narcotics most painful of the lot !! Post op swelling Nasendoscopy and extubate Swell, bleed, speech, tastes Regurgitation Robots Blocks if possible

39 Mueller manuever- preopAfter a forced expiration, an attempt at inspiration is made with closed mouth and nose, whereby the negative pressure in the chest and lungs is made very subatmospheric; the reverse of valsalva . Nasal endoscopy Site of obstruction and decide the type of surgery UPPP, UPPPP,Glossectomy, Lateral pharngoplasty

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41 Summary Definition Terms Clinical features Diagnosis Preop evaluationThank you all Definition Terms Clinical features Diagnosis Preop evaluation Intra op Post op