Obstructive Sleep Apnea Syndrome Dr. Amir Bar, Bnei-Zion Medical Center, Haifa

A “new syndrome”  “PubMed” search (Sleep Apnea; 0-18y): –1960’ 11 –1970’82 –1980’689 –1990’1012  A common syndrome  Has significant complications w/o Tx  Can be efficiently treated in the majority of cases >> Awareness and early diagnosis and Tx

EEG Non-REM Sleep Stages

EEG REM sleep

Sleep physiology REM M. ToneEOG NormalRapidWake +/-SlowSt 1 RelaxationNoneSt 2  Metabolism, GH secretion  Para-sympathetic predominance RelaxationNoneSt 3-4 “SWS” RelaxationNone  Dreams, Mental, Memory  Sympathetic predominance (MI)  Penile- erection  REM-Related OSA AtoniaRapidREM

Classification  Apnea: a Greek word - “want of breath” –Obstructive –Central –Mixed  m/p the Greeks describe obstructive type

Classification  Respiratory Disturbance Index (RDI) –Normal value <1-2 per hour of sleep 1. Apnea: complete airflow cessation ( 2 respiratory cycles) 2. Hypopnea: airflow reduction ( 2 respiratory cycles) 3. Respiratory Effort Related Arousal (RERA): prolonged flow limitation with associated arousal (Upper Airways Resistance Syndrome) Normal oxygen saturation

Epidemiology  Prevalence: –OSAS: 1-3% –Primary snoring (PS): 3-12%  Gender: –M/F ratio 1:1 (Adults: male predominance)  Age: –From neonates to adolescents –Commonest in preschool children (2-5y) (Peak incidence of adenotonsillar hypertrophy)  Race: –More common in African-American children ??

Nocturnal presentation  Apnea  Dyspnea  Snoring  Mouth breathing  Restless sleep

Pathophysiology Closed AW Opened AW Insp. Neg. pressure Anatomical factors Pharyngeal dilators Muscle relaxation (Sleep) Muscle atonia (REM) Neuromuscular dis

Upper Airways

Anatomical Factors

Neuromuscular Factors

Pathophysiology  Vast majority of cases are associated with adeno-tonsillar hypertrophy (AT- Ht)  Obesity in children is a risk factor for OSAS, and the severity of OSAS is proportional to the degree of obesity –In contrast to adults, most OSAS children are not obese (may have FTT)

Pathophysiology  Although strongly associated with AT-Ht, childhood OSAS is not caused by AT-Ht alone: –No obstruction during wakefulness –Adenotonsillar size and OSAS are not correlated –Deficit in arousal mechanisms Elevated arousal thresholds in response to hypercapnia and increased UA resistance –Abnormal centrally mediated activation of UA muscles

Complications  CVS – systemic and pulmonary HTN  Neurocognitive/behavioral problems  FTT  Enuresis

OSAS: PSG screen Chin EMG ECG Airflow Peripheral Pulse Volume BP Leg Mt. Oximetry EEG

Complications: CVS  Cor-pulmonale - used to be a common presentation, but is currently rare –When it does develop-can be reversed by Tx Tal, Pediatr Pulmonol, 1988:  Ventriculography in children who had abnormal questionnaire for OSAS: –37% had Rt. ventricular EF  –67% had abnormal wall motion –All of the 11 pt who had a repeat evaluation after T&A showed improvement

Complications: CVS Shiomi, Chest, 1993:  Pulsus-paradoxus and leftward shift of the inter-ventricular septum in 3/6 children with OSAS –Correlated with negative esophageal pressures but not with oxygen desaturation, reversed with CPAP

Complications: CVS Am J Respir Crit Care Med Apr 24 h ambulatory BP in children with sleep- disordered breathing  Background: OSAS causes intermittent elevation of systemic BP during sleep  Objective: to determine whether obstructive apnea in children has a tonic effect on diurnal BP  Conclusion: OSA in children is associated with 24 h BP dysregulation

Complications: CVS AAP The Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents PEDIATRICS Vol. 114 No. 2 August 2004

Complications: CVS

Complications : Neurocognitive & Behavioral Guilleminault, Lung, 1981:  50 children with OSAS (PSG) –84% - excessive daytime sleepiness –76% - behavior disturbance –42% - hyperactive –16% - school performance 

Complications : Neurocognitive & Behavioral Gozal, Pediatrics, 1998:  297 first graders who were in the lowest 10 th academically were evaluated for OSAS by questionnaire combined with home oximetry –54/297 (18.1%) had positive results (recommended T&A) –24/54 underwent T&A and improved their grading significantly, with no change in the untreated OSAS group or the non-OSAS group

Complications : Neurocognitive & Behavioral Gozal D, Sleep, 2004 Health-related Quality of Life and Depressive Symptoms in Children with Suspected Sleep- Disordered Breathing  Conclusions: Children with suspected OSAS, regardless of the severity of RDI or the presence of obesity, had more impairments in quality of life and depressive symptoms than did children who did not snore

Complications : Neurocognitive & Behavioral Pillar, Sleep, 2004 Sleep Disorders and Daytime Sleepiness in Children with ADHD  Of the children with ADHD, 17 (50%) had signs of OSAS, compared with 7 of the control group (22%, P <.05)  Children with ADHD demonstrate objective daytime somnolence (by MSLT), which may explain the beneficial effects of Tx with stimulants  Primary sleep disorders, especially sleep-disordered breathing and PLMS, should be looked for

Complications: FTT  FTT in OSAS children and reports of growth spurt following T&A  Proposed mechanisms: 1.Low caloric intake Dysphagia 2.High caloric expenditure Work of breathing  3.Abnormal GH secretion Interrupted SWS, post T&A - IGF 

Complications : Enuresis  Brooks, J Pediatr, 2003:  Children 4 y and older who had suspected OSAS were asked about enuresis –160 pt (90/70; M:F) –41% had enuresis (primary/secondary - 3:1) –RDI <1: significantly lower prevalence of enuresis (17 vs. 47%) –The prevalence of enuresis is associated to the OSAS severity (1-5, 5-15, or >15 events per hour)

Complications : Enuresis Weider, Otolaryngol Head Neck Surg, 1991:  115 enuretic children undergoing T&A –66% and 77% reduction in enuretic nights 1m and 6 m Post-T&A –In the group with secondary enuresis, 100% were dry 6 m Post-T&A

Evaluation: Polysomnography (PSG)  PSG is the gold STD for diagnosis  Establishment of diagnosis and severity –Prediction of complications, particularly in the immediate Post-Op period –Pre-Op baseline for Post-Op further evaluation  High costs and shortage of sleep labs >> screening techniques

Evaluation: Screening  Questionnaires  Snoring audiotapes  ENT exam –low sensitivity and specificity  Nocturnal Videotapes  Oximetry  Nap-PSG –High false-negative rate, indicative if positive

Evaluation: Pulse Oximetry Brouillette, Pediatrics, 2000:  349 children, pulse oximetry during PSG –OSAS prevalence – 60.2% –PPV - 97% –NPV - 53%

Treatment: T&A  Tonsillectomy with or w/o adenoidectomy is efficient Tx for OSAS  Clinical improvement of symptoms and post-Op complications: CVS, neurocognitive, enuresis, growth Suen, Arch Otolaryngol Head Neck Surg, 1995:  69 with susp OSAS had PSG, 35/69 had RDI > 5 and referred for T&A, 30/35 had T&A, 26/30 had follow-up PSG –Cure rate 85% –Post-Op snoring: NPV - 100%, and PPV - 57% –A high Pre-Op RDI (>19) was a strong predictor of abnormal Post-Op residual abnormality

Treatment: T&A  Nieminen, Arch Otolaryngol Head Neck Surg. 2000: –95% cure rate for a group of 21 children after T&A or tonsillectomy –Postoperative snoring NPV 100%, PPV 20% –73% of this group had a previous adenoidectomy, indicating the lack of efficacy of adenoidectomy alone

Treatment: T&A  Post-Op respiratory compromise (16-27%)  Causes: –Upper airway edema –Increased secretions –Respiratory depression – 2 nd to analgesic/anesthetic agents  Risk factors –Age <3 yr – severe OSAS –Children with additional medical conditions

Treatment: T&A  Follow-up PSG (6–8 wk Post-Op), to ensure that additional Tx is not required –Children with additional risk factors –Children with a Pre-Op high RDI

Other Tx alternatives  Uvulopharyngopalatoplasty (UPPP): in CP pt and hypotonic upper airway muscles; it has not been studied in the uncomplicated pediatric pt  Oral appliances has not been reported in children (it may adversely affect the facial configuration of the growing child)  In children, CPAP is usually used when T&A is unsuccessful or contraindicated rather than as a primary treatment –Young infants –Medical conditions

Treatment: Oxygen  Improved oxygenation during sleep, w/o obstruction worsening  PCO 2 : –Few individuals show marked increase in PCO 2 –With no apparent predictive factors for which pt would develop hypercapnia  Oxygen should never be administered w/o 1 st measuring PCO 2 response  Oxygen does not address many of the associated pathophysiological features

The end !