Upper Airway In Children Research Articles

Upper airway size analysis by magnetic resonance imaging of children with obstructive sleep apnea syndrome.

Detailed analysis of the upper airway has not been performed in children with obstructive sleep apnea. We used magnetic resonance imaging and automatic segmentation to delineate the upper airway in 20 children with obstructive sleep apnea and in 20 control subjects (age, 3.7 +/- 1.4 versus 3.9 +/- 1.7 years, respectively). We measured mean and minimal cross-sectional area, length, and volume of: (1) the total airway; (2) regions along the adenoid, tonsils, and where adenoid and tonsils overlap; and (3) 10 segments at 10% increments along the airway. The mean cross-sectional area of the total airway of the obstructive sleep apnea group was significantly smaller in comparison with the control group, 28.1 +/- 12.6 versus 47.1 +/- 18.2 mm2, respectively (p < 0.0005). Minimal cross-sectional area and airway volume were smaller in this group, 4.6 +/- 3.3 versus 15.7 +/- 12.7 mm2 (p < 0.0005), and 1,129 +/- 515 versus 1,794 +/- 846 mm3 (p < 0.005), respectively. Regional analysis suggested that the upper airway in children with obstructive sleep apnea is most restricted where adenoid and tonsils overlap. Segmental analysis demonstrated that the upper airway is restricted throughout the initial two-thirds of its length and that the narrowing is not in a discrete region adjacent to either the adenoid or tonsils, but rather in a continuous fashion along both.

Magnetic Resonance Imaging of the Upper Airway Structure of Children with Obstructive Sleep Apnea Syndrome

The anatomical relationships between lymphoid, bony, and other tissues affecting the shape of the upper airway in children with obstructive sleep apnea syndrome (OSAS) have not been established. We therefore compared the upper airway structure in 18 young children with OSAS (age 4.8 +/- 2.1 yr; 12 males and 6 females) and an apnea index of 4.3 +/- 3.9, with 18 matched control subjects (age, 4.9 +/- 2.0 yr; 12 males and 6 females). All subjects underwent magnetic resonance imaging under sedation. Axial and sagittal T1- and T2-weighted sequences were obtained. Images were analyzed with image-processing software to obtain linear, area, and volumetric measurements of the upper airway and the tissues comprising the airway. The volume of the upper airway was smaller in subjects with OSAS in comparison with control subjects (1.5 +/- 0.8 versus 2.5 +/- 1.2 cm(3); p < 0.005) and the adenoid and tonsils were larger (9.9 +/- 3.9 and 9.1 +/- 2.9 cm(3) versus 6.4 +/- 2.3 and 5.8 +/- 2.2 cm(3); p < 0.005 and p < 0.0005, respectively). Volumes of the mandible and tongue were similar in both groups; however, the soft palate was larger in subjects with OSAS (3.5 +/- 1.1 versus 2.7 +/- 1.2 cm(3); p < 0.05). We conclude that in children with moderate OSAS, the upper airway is restricted both by the adenoid and tonsils; however, the soft palate is also larger in this group, adding further restriction.

Magnetic resonance imaging of the upper airway in children with Down syndrome.

As compared with control subjects, children with Down syndrome have different size and shape relationships among tissues composing the upper airway, which may predispose them to obstructive sleep apnea (OSA). We hypothesized that Down syndrome children without OSA have similar subclinical differences. We used magnetic resonance imaging to study the upper airway in 11 Down syndrome children without OSA (age, 3.2 +/- 1.4 yr) and in 14 control subjects (age, 3.3 +/- 1.1 yr). Sequential T1- and T2-weighted spin-echo axial and sagittal images were obtained. We found a smaller airway volume in subjects with Down syndrome (1.4 +/- 0.4 versus 2.3 +/- 0.8 cm(3) in controls, p < 0.005). Subjects with Down syndrome had a smaller mid- and lower face skeleton. They had a shorter mental spine-clivus distance (5.7 +/- 0.6 versus 6.2 +/- 0.4 cm, p < 0.05), hard palate length (3.2 +/- 0.4 versus 3.7 +/- 0.2 cm, p < 0.005), and mandible volume (11.5 +/- 3.7 versus 16.9 +/- 2.9 cm3, p < 0.0005). Adenoid and tonsil volume was significantly smaller in the subjects with Down syndrome. However, the tongue, soft-palate, pterygoid, and parapharyngeal fat pads were similar to those of control subjects. This study shows that Down syndrome children without OSA do not have increased adenoid or tonsillar volume; reduced upper airway size is caused by soft tissue crowding within a smaller mid- and lower face skeleton.

Correlation of findings on direct laryngoscopy and bronchoscopy with presence of extraesophageal reflux disease.

To determine the correlation between findings at direct laryngoscopy and bronchoscopy and presence of extraesophageal reflux disease (EERD). Retrospective chart review Operative notes of 155 children undergoing direct laryngoscopy and bronchoscopy between 1996 and 1999 for airway symptoms for whom there was a suspicion of EERD were examined. Gastroesophageal reflux disease (GERD) was considered present if at least one test was positive (including upper GI series, pH probe, gastric scintiscan, or esophageal biopsy). A total of 130 (84%) patients had GERD diagnosed. Ninety percent had at least one laryngotracheal abnormality: 83% had an abnormal larynx and 66% had an abnormal trachea. Laryngeal abnormalities in GERD included postglottic edema, 69%; arytenoid edema, 30%; large lingual tonsil, 16%; vocal fold edema, 12%; vocal fold nodule, 12%; ventricular obliteration, 5%; and hypopharyngeal cobblestoning, 3%. Tracheobronchial abnormalities in GERD included tracheal cobblestoning, 33%; blunting of carina, 12.5%; subglottic stenosis, 11%; increased secretions, 11%; and generalized edema or erythema, 5%. The best sensitivity or specificity was obtained by combining postglottic edema, arytenoid edema, and vocal fold edema, resulting in a sensitivity of 75% and a specificity of 67%. Positive predictive value was 100% for the combination of postglottic edema and any vocal fold or ventricular abnormality. Laryngoscopy and bronchoscopy can reveal findings with a high positive predictive value for the presence of GERD. Endoscopy of the upper airway in children with clinical signs and symptoms of EERD is a promising tool for diagnosis.

The effect of prone posture on nasal temperature in children in relation to induction of staphylococcal toxins implicated in sudden infant death syndrome

The incidence of sudden infant death syndrome (SIDS) has declined in response to campaigns discouraging the prone sleeping position. Recent work suggests some SIDS death may be in response to bacterial toxins produced in the upper airway. A minimal temperature of 37°C is required for induction of the pyrogenic toxins of Staphylococcus aureus identified in many SIDS infants. This aim of this study was to test the hypothesis that the prone position raises the temperature of the upper airways in children. A pilot study of 10 children (aged 3–8) and a main study of 30 children were carried out. Nasal septal temperatures were measured with an infra-red thermometer with the subjects in upright and prone positions under controlled conditions of ambient temperature and humidity. In both the pilot study and main study, nasal temperatures in the prone position were significantly higher ( P<0.01) Five subjects’ prone readings were 37°C or higher. These findings suggest that lying prone raises the upper airway surface temperature towards that required for toxin production. This could be one means by which the prone sleeping position contributes to the risk of SIDS.

The effect of prone posture on nasal temperature in children in relation to induction of staphylococcal toxins implicated in sudden infant death syndrome.

The incidence of sudden infant death syndrome (SIDS) has declined in response to campaigns discouraging the prone sleeping position. Recent work suggests some SIDS death may be in response to bacterial toxins produced in the upper airway. A minimal temperature of 37 degrees C is required for induction of the pyrogenic toxins of Staphylococcus aureus identified in many SIDS infants. This aim of this study was to test the hypothesis that the prone position raises the temperature of the upper airways in children. A pilot study of 10 children (aged 3-8) and a main study of 30 children were carried out. Nasal septal temperatures were measured with an infra-red thermometer with the subjects in upright and prone positions under controlled conditions of ambient temperature and humidity. In both the pilot study and main study, nasal temperatures in the prone position were significantly higher (P < 0.01) Five subjects' prone readings were 37 degrees C or higher. These findings suggest that lying prone raises the upper airway surface temperature towards that required for toxin production. This could be one means by which the prone sleeping position contributes to the risk of SIDS.

Upper airway disease.

More than 40% of children admitted to hospitals have respiratory disorders. Acute respiratory emergencies are either upper or lower airway obstructive diseases due to various etiological factors. A comprehensive knowledge and understanding of the anatomical variation of the upper airway in children is essential in the management of the critically ill.

Preliminary data on the effect of pharyngeal flaps on the upper airway in children with velopharyngeal inadequacy.

Seven patients who received pharyngeal flaps for velopharyngeal incompetence (VPI) were studied to assess the effect of the procedure on nasal airway size. The findings suggest that the pharyngeal flap does not significantly decrease the upper airway in all patients. The effect of the flap did not correlate with the type of cleft, and was most pronounced in the inspiratory phase of the breathing cycle. Reasons for this variable effect, assumed to be related to an already impaired nasal airway in most cleft patients, are discussed.

Plasma lignocaine levels during paediatric endoscopy of the upper respiratory tract. Relationship with mucosal moistness.

Plasma lignocaine levels were measured at 5, 10 and 15 minutes following local application (4 mg/kg) to the upper airway in children who underwent endoscopy under general anaesthesia. These levels were then correlated with the appearance of the moistness of the airway mucosa secondary to premedication with atropine. This latter assessment was carried out by one anaesthetist who used a predetermined scale of 1-5, where 1 was very dry and 5 very wet. Significantly higher (p less than 0.05) plasma levels of lignocaine were achieved when the mucosa was 'very dry' especially in children under 2 years of age. The total dose of lignocaine applied to the upper airway of children should probably be reduced, in the presence of a 'dry' mucosa after effective antisialogogue premedication, and especially when less than 2 years of age.

Evaluation of the upper airway in children: Thomas A. WeimertEar Nose Throat J. 1987; 66: 196–200

Evaluation of the upper airway in children: Thomas A. WeimertEar Nose Throat J. 1987; 66: 196–200

Emergency treatment of foreign-body obstruction of the upper airway in children

Recently, the Committee of Accident and Poison Prevention of the American Academy of Pediatrics presented its recommendations regarding the emergency management of the choking child. Renewed interest was stimulated in the controversy regarding whether back blows, abdominal thrusts, or chest thrusts should be used in the initial treatment of foreign-body obstruction of the upper airway. Two cases exemplifying problems in patient management are presented as a basis of focusing on the current controversy. Review of the clinical and experimental data suggests that back blows, followed by either chest or abdominal thrusts, are a reasonable approach to emergency airway obstruction, but that this recommendation is based on limited evidence.

Obstructions of the upper airway in children as reflected on the chest radiograph.

Alterations in the appearance of the heart and lungs that should lead one to suspect the possibility of upper airway obstruction in children are: distension of the hypopharynx, underaeration of the lungs, cardiac enlargement, cardiac enlargement with passive congestion, and pulmonary edema without cardiac enlargement.