The pathogenesis of pediatric OSA Stijn Verhulst, MD, PhD Pediatric - - PowerPoint PPT Presentation
The pathogenesis of pediatric OSA Stijn Verhulst, MD, PhD Pediatric - - PowerPoint PPT Presentation
The pathogenesis of pediatric OSA Stijn Verhulst, MD, PhD Pediatric Pulmonology and Pediatric Sleep Medicine Pediatric Pulmonology and Pediatric Sleep Medicine Antwerp University Hospital Belgium stijn.verhulst@uantwerp.be Introduction
Introduction
- Combinatie kritische anatomie en additionele
risicofactoren
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Introduction
- This presentation will focus on 3 parts of the
pathogenesis that are becoming increasingly clinically relevant:
, The role of obesity as an anatomical risk factor
2
, The role of obesity as an anatomical risk factor , The role of upper airway inflammation , Natural history
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OBESITY
Prevalence
- Childhood obesity is associated with an
increased prevalence of obstructive sleep apnea.
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increased prevalence of obstructive sleep apnea.
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Prevalence
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Prevalence
- Both childhood obesity and OSAS are associated
with a number of complications.
- Second, obesity and OSAS can interact in
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- Second, obesity and OSAS can interact in
causing these complications, i.e. cardiovascular and metabolic complications.
KEY MESSAGE: An optimal treatment should therefore target
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both conditions. This requires a good knowledge of the (individual) contributing anatomical factors.
Anatomical correlates
- The exact contributions of both adenotonsillar
hypertrophy and obesity to the pathogenesis
- f OSAS are still controversial.
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- f OSAS are still controversial.
The scope of the problem
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Anatomical correlates
- However, the relation between obesity and
sleep apnea in children is complex…
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sleep apnea in children is complex…
Anatomical correlates
- AHI is not a unique marker of OSAS: BMI often
correlates better with other markers of the severity
- f sleep apnea, i.e. oxygen desaturation.
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Anatomical correlates
- AHI < 2
2 < oAHI < 5
- AHI ≥ 5
P VC (%pred)
106 ± 13 103 ± 13 95 ± 15 0.01
FEV1 (%pred)
104 ± 13 101 ± 14 95 ± 17 0.05 13 !"#
FEV1/VC (%pred)
99 ± 8 98 ± 7 101 ± 7 0.4
RVHe (%pred)
89 ± 36 86 ± 35 85 ± 26 0.6
TLCHe (%pred)
101 ± 21 101 ± 11 91 ± 20 0.03
FRCHe (%pred)
82 ± 21 76 ± 31 65 ± 21 0.008
Anatomical correlates
- Second, BMI is not the only marker of obesity.
However, there is limited data on the association between OSAS and markers of
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association between OSAS and markers of visceral adiposity in children.
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16 '( %) *+&&
Anatomical correlates
- Furthermore, the association seems to be age,
dependent:
, Obese children: Adenotonsillar hypertophy > Obesity
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, Obese teenagers: Obesity > Adenotonsillar hypertrophy
Anatomical correlates
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Anatomical correlates
19 "" ,
Anatomical correlates
20 "",
Anatomical correlates
- The magnitude of adenotonsillar hypertrophy
is more likely to be smaller in obese children compared to nonobese children with comparable AHI.
21 "",
- Increased Mallampati scores in obese children
suggest that soft,tissue changes and potentially fat deposition in the upper airway may play a significant role in obese children with OSA.
Anatomical correlates
22 %&&
Anatomical correlates
23 %&&
Anatomical correlates: treatment data
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Anatomical correlates: treatment data
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Anatomical correlates: treatment data
- Multi,center retrospective study investigated the
- utcome of adenotonsillectomy for OSAS in 578
children (50% obese):
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, AHI significantly dropped from 18.2±21.4 to 4.1±6.4 (p<0.001). , Only 157 (27.2%) had complete resolution of OSAS (AHI<1).
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Anatomical correlates: treatment data
27 012%"&
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Anatomical correlates: treatment data
30 *+"3
Anatomical correlates: treatment data
- 61 obese teenagers.
- 50% with OSAS.
- After 6 months, these subjects lost an average
- f 24 kg which corresponded to a relative
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- f 24 kg which corresponded to a relative
decrease in BMI of approximately 30%.
*+",
Anatomical correlates: treatment data
Definition of success Success rate (%) Apnea hypopnea index ≤ 2 62 Oxygen desaturation index ≤ 2 81
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Apnea hypopnea index ≤ 5 91
*+"
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Anatomical correlates: treatment data
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Functional imaging
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Obesity , conclusion
- The pathogenesis of OSA in obese children is
complex illustrated by suboptimal response to adenotonsillectomy.
- In view of the established link with metabolic
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- In view of the established link with metabolic
and cardiovascular morbidity, there is a clear need to validate tools that identify the anatomical contributors in the individual child.
Obese child with OSA Obese child with OSA Weight management Weight management Work up site
- f
Work up site
- f
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- f
- bstruction
- f
- bstruction
T&A T&A Non,invasive ventilation Non,invasive ventilation
Obesity , conclusion
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UPPER AIRWAY INFLAMMATION
Introduction
- The size of tonsils and adenoids increases
from birth to approximately 12 years of age.
- There is gradual concomitant growth in the
size of the skeletal boundaries of the upper airway.
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airway.
- Between 2 and 8 years of age, the tonsils and
adenoids are the largest in relation to upper airway size, resulting in a relatively narrower upper airway.
Introduction
- However, despite this relative physiological
narrowing, young children exhibit less collapsible upper airways when compared with adults:
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adults:
, Increased tonic activation UA muscles , Increased central ventilatory drive
Introduction
- Classical stimuli for proliferation:
, Environmental irritants
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, Recurrent infections
43 Kheirandish,Gozal et al, Expert Opin Investig Drugs, 2013
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- Cysteinyl leukotriene receptors are expressed
by small,size B,lymphocytes in the tonsillar
- mantle zones and by T,lymphocytes in the
tonsillar extrafollicular areas.
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tonsillar extrafollicular areas.
- Since these are immunologically active areas
participating in the generation of mature germinal centers, it is proposed that cysteinyl
- leukotriene receptors are involved in the
pathogenesis of lymphoid tissue hyperplasia.
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UA inflammation , conclusion
- Increased UA inflammation – leukotrien
modified.
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- Pharmacological treatment is an alternative to
adentonsillectomy.
- More data needed.
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NATURAL HISTORY
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