Comparison of Static Mechanical Properties of the  Passive Pharynx between Normal Children and Children with Sleep-disordered Breathing

Isono, Shiroh; Shimada, Akiko; Utsugi, Makoto; Konno, Akiyoshi; Nishino, Takashi

doi:10.1164/ajrccm.157.4.9702042

Cited by 177 publications

(98 citation statements)

References 11 publications

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“…relative hypotonia rather than atonia. This is suggested by comparing our data with that of Isono et al (29). They measured the upper airway closing pressure in the anesthetized, paralyzed state, i.e.…”

Section: Pfrsupporting

confidence: 67%

Upper Airway Dynamic Responses in Children with the Obstructive Sleep Apnea Syndrome

et al. 2005

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Normal children have a smaller upper airway than adults, but, nevertheless, snore less and have less apnea. We have previously shown that normal children have an upper airway that is resistant to collapse during sleep. We hypothesized that this resistance to collapse is due to preservation of upper airway neuromotor responses during sleep. Furthermore, we hypothesized that upper airway responses would be diminished in children with the obstructive sleep apnea syndrome (OSAS). We therefore compared the upper airway pressure-flow relationship during sleep between children with OSAS and controls. Measurements were made by correlating maximal inspiratory airflow with the level of nasal pressure applied via a mask. Neuromotor upper airway activation was assessed by evaluating the upper airway response to 1) hypercapnia and 2) intermittent, acute negative pressure. We found that children with OSAS had no significant response to either hypercapnia or negative pressure during sleep, compared with the normal children. After treatment of OSAS by tonsillectomy and adenoidectomy, there was a trend for normalization of upper airway responses. We conclude that upper airway dynamic responses are decreased in children with OSAS but recover after treatment. We speculate that the pharyngeal airway neuromotor responses present in normal children are a compensatory response for a relatively narrow upper airway. Further, we speculate that this compensatory response is lacking in children with OSAS, most likely due to either habituation to chronic respiratory abnormalities during sleep or to mechanical damage to the upper airway. In children, OSAS is related to adenotonsillar hypertrophy. Most children with OSAS have large tonsils and adenoids, and improve after T&A (1). Nevertheless, studies suggest that childhood OSAS is not due to anatomic abnormalities alone. Most obvious is the fact that patients with OSAS do not obstruct during wakefulness, when upper airway muscle tone is high. Although the upper airway may be narrower in children with OSAS than in those without, there is overlap between the groups (2). A small percentage of children with adenotonsillar hypertrophy but no other known risk factors for OSAS are not cured by T&A (1). Furthermore, a small percentage of children who were cured of their OSAS by T&A have been reported to develop a recurrence during adolescence (3,4). Thus, it appears that childhood OSAS is a dynamic process resulting from a combination of structural and neuromotor abnormalities, rather than from structural abnormalities alone. The upper airway above the level of the cartilaginous airway is a collapsible muscular tube that usually remains patent but has the potential to collapse to facilitate such functions as speech and swallowing. It comprises more than 30 pairs of muscles (5). Thus, neuromotor control of this area is important to maintain airway patency. Upper airway collapsibility during sleep is modulated by the central ventilatory drive (6). The upper airway dilatory muscles are respiratory musc...

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Section: Pfrsupporting

confidence: 67%

Upper Airway Dynamic Responses in Children with the Obstructive Sleep Apnea Syndrome

et al. 2005

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“…1,2 The upper airway volume and minimal cross-sectional area are significantly smaller in children with SDB and tend to be narrower laterally than in children without sleep disorders. [3][4][5][6] Early diagnosis of SDB, or potential associations of SDB, is essential to encourage normal facial development. 7,8 Reduced pharyngeal dimensions established early in life could potentially predispose to later development of SDB or even obstructive sleep apnoea, 9 as soft-tissue changes related to ageing, obesity or genetic background further reduce oropharyngeal patency.…”

Section: Introductionmentioning

confidence: 99%

Proposal of new upper airway margins in children assessed by CBCT

Anandarajah¹,

Abdalla²,

Dudhia³

et al. 2015

Dentomaxillofacial Radiology

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Objectives: Recently, studies have performed three-dimensional analyses of upper airways in children. However, there was a lack of airway delineation according to anatomical boundaries and/or easily mobile soft-tissue landmarks were used. The aim of the present study was to define new upper airway margins in children on CBCT according to anatomical bony landmarks and to validate the method. Methods: 25 scans were randomly selected from a larger database containing CBCT scans of children prior to orthodontic treatment (14 girls and 11 boys; mean age, 10.9 ± 2.5 years). Scans were evaluated by two observers. Specific head positioning and virtual orientation protocols were adopted and greyscale thresholding was established for each patient. Volume and minimum cross-sectional area of the oropharynx were calculated. Intra-and interobserver reliability were assessed by reassessment of the CBCTs 2 weeks later. Results: The new airway margins were defined superiorly by a line passing through the palatal plane (anterior nasal spine to posterior nasal spine) extending to the posterior wall of the pharynx, inferiorly by a line passing from the anterosuperior edge of C4 to menton, anteriorly by a line passing from the soft palate to menton, posteriorly and laterally by the respective pharyngeal walls. Method error for airway volume and minimal cross-sectional area was #2.00%, and intra-and interobserver reliability ranged from 0.99 to 1.00. Conclusions: The proposed protocol utilizes easily identifiable bony landmarks to delineate the upper airway on cone beam scans of children and was found to be reliable and reproducible.

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“…22 Upper air way collapsibility is markedly increased in both sleeping and anesthetized children. 23 Propofol and barbiturate can exacerbate upper air way obstruction and increase the risk of respiratory depression/apnoea. 24 In contrast to other drugs, Ketamine is shown to preserve hypopharyngeal size in adults.…”

Section: Discussionmentioning

confidence: 99%

Comparison of propofol and thiopentone along with ketamine for paediatric MRI sedation

et al. 2016

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INTRODUCTIONMagnetic resonance imaging (MRI) requires the patient to stay still for at least 15 minutes to one hour in a noisy and claustrophobic environment. It is difficult especially in infants and children without drug induced sleep. Hence anaesthesiologists are discovering safe and successful combination of drugs. 1Propofol is discussed to be a best of all intravenous (I.V.) drugs for paediatric sedation because of its faster induction and quick recovery.2 Magnetic resonance imaging scanning for children is a big challenge for anaesthesiologist for providing adequate sedation without compromising airway and haemodynamics. 3 The success of sedation during MRI is typically assessed by two factors 1) safety during sedation 2) successful completion of test that is good quality of radiological image without artefacts. It can be achieved from motion less body during scan. 4 Propofol yields faster induction and faster emergence from sedation but it may cause hypotension. 5Thiopentone I.V bolus has been used routinely 6 but the duration of recovery and sedation is unpredictable. 7 We aimed to study the effectiveness between Propofol and Thiopentone along with Ketamine and other premedications. ABSTRACTBackground: Children are very much scared to undergo magnetic resonance imaging (MRI) brain or any body part even along with their parents for about 15 to 25 minutes. We investigated the combination of Propofol Ketamine and Thiopentone Ketamine along with Glycopyrolate and Midazolam premedication to see safe and better sedation group for paediatric MRI. Methods: We investigated randomly 50 children of age three to five years prospectively. Children were premedicated with Glycopyrolate 0.01 mg/kg and Midazolam 0.05 mg/kg per body weight intravenously. Ketamine 1 mg/kg body weight was given just before shifting into the MRI machine. After body positioning either Propofol (PK group) or Thiopentone (TK group) 1 mg/kg body weight was given slowly. Children were monitored for electrocardiogram (ECG), arterial oxygen saturation (SpO 2 ) and respiratory rate continuously. Oxygen supplementation was through the oxygen (O 2 ) mask. Three parameters were studied 1) Repetition of drug 2) Respiratory distress during scan period and 3) Recovery time. Results: The pre-interventional characteristics including age, sex, weight, ASA grade, were comparable between two groups (p>0.050). Repetition in PK group was high compared to TK group (40% vs 8%; p=0.0081). Respiratory distress was comparable in both the groups (16% vs 24%; p=0.480) whereas recovery time was significantly shorter for PK group (4.62 ± 0.53 vs 9.86 vs 1.28; p<0.001). Conclusions: Thiopentone Ketamine combination results in lower repetition rate while Propofol Ketamine offers shorter recovery period. However, respiratory distress is almost similar.

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Comparison of Static Mechanical Properties of the Passive Pharynx between Normal Children and Children with Sleep-disordered Breathing

Cited by 177 publications

References 11 publications

Upper Airway Dynamic Responses in Children with the Obstructive Sleep Apnea Syndrome

Upper Airway Dynamic Responses in Children with the Obstructive Sleep Apnea Syndrome

Proposal of new upper airway margins in children assessed by CBCT

Comparison of propofol and thiopentone along with ketamine for paediatric MRI sedation

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