Peri-Operative Management of Obstructive Sleep Apnea

Carolyn D’Ambrosio, MD, MS, FCCP, DABSM Associate Professor of Medicine Director, The Center For Sleep Medicine, Tufts Medical Center

Disclosure • Advanced ICUcare

Outline • Pre-Operative Assessment • Intraoperative Considerations • Post-operative management & complications • Summary and recommendations

Unexplained and Unexpected Post-Op Deaths, within 7 Days of operation, most often occur at Night. Rosenberg J et al., Br J Surg 1992

Children’s Hospital, Oakland January, 2014

Jahi McMath • Dec 9, 2013: T & A + sinus surgery for OSA • Awake and speaking post-op • In ICU she developed severe bleeding, cardiac arrest • Declared Brain Dead a few days later

OSA Risk Factors • • • • • • •

Obesity, neck size >17 inches (OR 6.10) Male gender Snoring Craniofacial abnormalities Nasal obstruction/redundant soft palate Endocrine abnormalities (NIDDM 36%) Family History

Increased Risk of OSA • • • • • • • • • •

Depression/cognitive deficits Tobacco use CVD/HTN Glaucoma Alcoholism ESRD GERD Atrial Fibrillation Impotence/loss of libido Pre-eclampsia

Site of Obstruction in OSA Tongue - Posterior Pharynx Soft Palate - Posterior Pharynx Lateral Pharyngeal Wall Opposition Circular Closure of Pharynx

Pathophysiology • Hypoglossal nerve exquisitely sensitive to anesthesia • Genioglossus muscle critical to maintaining airway patency • Post-operative airway tissue edema

Minute Ventilation (L/min)

Ventilatory Response to CO2 30 25 20

Normal Awake

15

OSA, Resistive Load, Sleep

10 5 0 30

40

50

60

Arterial Carbon Dioxide (Torr)

Pre-operative Evaluation • Clinical S & S of OSA – – – – – –

Adults: BMI 35 kg/m2 Pediatric: 95th percentile for age and sex Neck circ. 17” (men), 16” (women) Craniofacial abnormalities of upper airway Anatomical nasal obstruction Tonsils touching or nearly touching ASA : Practice Guidelines Anesthology Feb 2014

Pre-operative Evaluation • History of apparent airway obstruction during sleep: 2 or more: – Loud snoring – Frequent snoring – Witnessed apnea – Awakes choking – Frequent arousals from sleep ASA : Practice Guidelines Anesthology Feb 2014

Pre-operative Evaluation • Somnolence – Frequent sleepiness or fatigue – Falls asleep in non-stimulating environment – Pediatric patient: sleepy in school, easily distracted, aggressive, irritable or difficult to arouse at wake time ASA : Practice Guidelines Anesthology Feb 2014

Pre-operative Evaluation • Pediatric patients: – Intermittent vocalizations during sleep – Parent reports restless sleep, difficulty breathing or struggling to breathe – Night terrors – Sleeps in unusual position – New onset ( secondary) bedwetting ASA : Practice Guidelines Anesthology Feb 2014

Pre-operative Evaluation • Strongly consider PSG in high-risk children – – – –

< 2 years-old Obesity Neuromuscular weakness Craniofacial abnormality

Preoperative Evaluation • Berlin Questionnaire (10 item) – Validated in primary care and afib – Ok for pre-op but cumbersome scoring Chung F et al., J Clin Anes 2007

Berlin Questionnaire • 10 questions (snoring, BP, fatigue, etc) • Each answer for each question has a value ( a=1 point, b= 2 points, etc) • Two categories of questions • Sum of the points indicates high risk or low risk

Preoperative Evaluation • STOP-BANG – – – – – – – –

Snoring Tiredness Observed apnea Pressure ( HTN ) BMI >35 AGE >50 Neck circ >40cm Gender male Chung F et al., Anesth 2008

Preoperative Evaluation • STOP-BANG – Sensitivity: • 65.6% for AHI >5, • 84%, AHI >10 93%, • AHI >15 100% if yes to two of the questions and BANG all positive – No statistically significant difference between STOP-BANG, BQ, or ASA checklist Chung F et al., Anesth 2009

Induction/Intubation • OSA patients 8 x more likely to be difficult intubation Siyam MA, Benhamou D Anesth Analg 2002

• 66% of patients who were difficult to intubate, subsequently dx with OSA Chung F, et al., Anesthiology 2006

Intubation • Neck circumference is the single best predictor of difficulty with intubation • 5% with 40 cm neck (15.7”) • 35% with 60 cm neck (23.6”) Brodsky, et al., Anesth Analg 2002

Induction Halothane – Dose dependent decrease in muscle activity with the genioglossus muscle being amongst the most sensitive

Ochiai, R. et al., Anesthesiology 70: 812816, 1989

Inspiratory EMG (%Control)

Inspiratory Muscular EMG 100 90 80 70 60 50 40 30 20 10 0

Diaphragm Intercostal Genioglossus

1

1.5

2

2.5

3

Halothane Concentration (%)

Ochiai et al, 1989

Induction • UAO – Head-jaw position, oropharyngeal or nasopharyngeal airway with CPAP reduces obstruction Connolly, LA J Clin Anesth 1991; 3:461-9

Induction Intravenous agents • Rapid, less vomiting & laryngospasm • Increased risk of collapsed upper airway (midazolam, propofol) » Montravers P et al., Br J Anaesth 1992 » Eastwood PR, et al., Anesth 2005

Inhalation agents • Decrease ventilatory responses to CO2 & O2

Induction • Opioids. – effect on upper airway muscles is unknown. – dampen brainstem ventilatory responses, so apneas are prolonged. – Children with OSA have a greater analagesic sensitivity to morphine ( Brown et al., Anesth 2006). Neuromuscular Blockers. UA muscles more sensitive to nondepolarizing NMB (Musich and Walts, Anesthesiology 1986).

Intra-operative Care in OSA • Regional Anesthesia is best when possible • General Anesthesia: – Extreme vulnerability of UAO with minimal sedation – Difficult tracheal intubation – Higher risk of gastroesophageal reflux

Post-operative OSA Care Loss of arousal response important: • Residual anesthesia • Pain medication • Neuromuscular blockage • Sleep deprivation • Sleeping pills

Complications of Airway Surgery in OSA • Hypoxemia to Respiratory Failure • Acute upper airway obstruction during induction (Failed intubation) • Airway obstruction post-extubation • Pulmonary edema following relief of UAO • Arrhythmias worsened by hypoxemia

Post-operative Complications in OSA • Early (day 1): episodic desaturations – Thought to be residual opioids and return of sleep affecting UA and central respiratory drive Catley, et al., Aneshtesiology 1985; 63: 20-8

• Late (day 2 - 5): episodic desaturations – Thought to be REM rebound Reeder, et al, Anaesthesia 1992; 47:110-5

Perioperative Risk Factors Respiratory Complications in Patients With OSA Undergoing Airway Surgery

Deaths in Children Post-AT

•Goldman et al, Laryngo 2013: 123: 2544-

Post-Operative Complications OSA not associated with increased risk of death or anoxic brain injury following T & A. Adverse events due to apnea, narcotics were more likely to occur in first three days Physicians doing less than 200 T & A’s a year were more likely to have adverse outcomes Goldman JL, Baugh RF, et al The Laryngoscope 2013

Post-operative Complications • Preoperative Dx of OSA is an independent predictor of atrial fibrillation after CABG. Mooe T et al., Coron Artery Dis 1996.

Role of CPAP • Post-operative complications in patients with TKR: • Those with OSA using CPAP had far fewer serious post-op complications than those not yet on CPAP Gupta, RM, et al., Mayo Clin Proc 2001

Acute Pulmonary Edema Following Relief of UAO • Reported after T & A for OSA as well as after intubation in croup • Pathophysiology unclear, but likely related to sudden increase in venous return postoperatively • Management – CPAP post-operatively

CPAP Safety Post-Op • CPAP post-gastrojejunostomy showed no increased incidence of anastomotic leakage. Huerta et al., J Gastrointest Surg 2002.

General Recommendations • • • • •

Avoidance of pre-operative sedation Supplemental oxygen and oximetry Limit intra-operative narcotics Consider awake intubation if difficulty likely Extubate only when fully awake, consider sitting position • Overnight post-operative monitoring for high-risk patients

Recommendations in Children Intensive post-operative monitoring in children • < 2 years-old • Severe OSA • Craniofacial or Neuromuscular Disorders • History of Prematurity • Intraoperative airway difficulties, hypoxemia or hemorrhage

Summary • In all age groups – OSA predisposes to airway collapse, which carries risks with anesthesia and in the perioperative period – Patients with OSA have significant comorbidities that need consideration during the peri-operative period – Pre-operative screening is critical to identify patients at high risk and treatment with cpap may reduce post op respiratory complications