Severity Of Upper Airway Obstruction Research Articles

Effect of Sleep Position on Sleep-Disordered Breathing in Young Children With Unrepaired Incomplete Cleft Palates.

Children with cleft lip/palate are usually faced with upper airway problems after surgical repair. The severity of upper airway obstruction is more likely associated with the age and preoperative diagnosis of obstructive sleep apnea (OSA). This study aimed to investigate the severity of OSA in toddlers before palatoplasty from the perspective of polysomnography. In this retrospective cohort study, 97 children with unrepaired cleft palate and habitual prone sleeping were identified with a mean age of 1.6 years (SD 0.6) and divided into 2 age groups (1.5 year or younger and older than 1.5 year). Detailed information was collected including demographics, sleep parameters, and respiratory disturbances. Polysomnography results showed these children were at high risks of OSA with averagely moderate severity at night during their early childhood [apnea-hypopnea index 7.2±3.2 events/hour; obstructive apnea index (OAI) 6.5±2.8 events/hour]. Positional OAI was greatly lower in prone than that in laterals or in supine. Far more sleep time was spent in prone than in supine (42.9%±42.2% versus 8.5%±15.7%), which were consistent with parental reporting of prone sleeping habits. There were no significant differences found between the 2 age groups in respiratory disturbances such as apnea-hypopnea index, OAI, mean oxygen saturation, and nadir oxygen saturation ( P =0.097-0.988). Thus, prone sleeping with a history of snoring might be indicators for early screening for OSA in the cleft population. Adequate attention should be paid to their upper airway and, if available, overnight polysomnography should be performed to ascertain their potential respiratory problems before repair surgery.

Treatment strategies for orofacial myofunctional disorders and malocclusions associated with different sites of upper airway obstruction in children

The impact of respiratory function on children's craniofacial growth has received increasing attention from orthodontists and parents. There is a higher pediatric sleep-disordered breathing risk prevalence in the orthodontic population compared with a general population sample, and orthodontic practitioners need to pay close attention to the respiratory function of their pediatric patients. For children with upper airway obstruction and related dentofacial and functional abnormalities, clinicians should comprehensively consider the site and severity of upper airway obstruction, the clinical feature of malocclusion and other factors to develop an individual, multidisciplinary treatment plan, providing favorable conditions for the development of the children's craniofacial morphology and the whole body.

Severity stages of obesity-related breathing disorders – a cross-sectional cohort study

IntroductionThere is a general underappreciation of the spectrum of obesity-related breathing disorders and their consequences. We therefore compared characteristics of obese patients with eucapnic obstructive sleep apnea (OSA), OSA with obesity-related sleep hypoventilation (ORSH) or obesity hypoventilation syndrome (OHS) to identify the major determinants of hypoventilation. Patients and methodsIn this prospective, diagnostic study (NCT04570540), obese patients with OSA, ORSH or OHS were characterized applying polysomnography with transcutaneous capnometry, blood gas analyses, bodyplethysmography and measurement of hypercapnic ventilatory response (HCVR). Pathophysiological variables known to contribute to hypoventilation and differing significantly between the groups were specified as potential independent variables in a multivariable logistic regression to identify major determinants of hypoventilation. ResultsTwenty, 43 and 19 patients were in the OSA, ORSH and OHS group, respectively. BMI was significantly lower in OSA as compared to OHS. The extent of SRBD was significantly higher in OHS as compared to OSA or ORSH. Patients with ORSH or OHS showed a significantly decreased forced expiratory volume in 1 s and forced vital capacity compared to OSA. HCVR was significantly lower in OHS and identified as the major determinant of hypoventilation in a multivariable logistic regression (Nagelkerke R2 = 0.346, p = 0.050, odds ratio (95%-confidence interval) 0.129 (0.017–1.004)). ConclusionAlthough there were differences in BMI, respiratory mechanics and severity of upper airway obstruction between groups, our data support HCVR as the major determinant of obesity-associated hypoventilation.

Impact of Cleft Palate on Tongue-Based Upper Airway Obstruction in Pierre Robin Sequence: Implications for Mandibular Distraction Osteogenesis and Timing of Cleft Palate Repair

The objectives of this study are to analyze the impact of cleft palate (CP) on upper airway obstruction using polysomnography in patients with Pierre Robin Sequence (PRS) undergoing mandibular distraction osteogenesis (MDO) and subsequent CP repair. A single-surgeon, retrospective chart review was performed of all patients with nonsyndromic PRS treated with MDO. Severity of upper airway obstruction was evaluated pre- and post-distraction via polysomnography. Details of MDO and CP repair were collected and any complications recorded. Twenty-one nonsyndromic PRS patients with CP and 6 patients without CP met inclusion criteria. There was no significant difference in predistraction apnea-hypopnea index between the 2 groups (53.4 ± 42.1 versus 34.4 ± 18.9; P = 0.3). Patients with CP had significantly higher predistraction SpO2 saturation (94.5 ± 1.6% versus 91.0% ± 4.8%; P = 0.01), SpO2 nadir (74.5% ± 9.1% versus 63.6% ± 11.6%; P = 0.03) and lower percentage time spent below 90% SpO2 (6.0% ± 7.2% versus 23.6% ± 29.9%; P = 0.04). The rate of oronasal fistulas formation was 38%. The time between MDO and CP repair was shorter for patients with complications (250.8 ± 3.3 versus 370.8 ± 191.9 days; P = 0.08). Five patients experienced relapse of respiratory difficulties after CP repair. The presence of CP in nonsyndromic PRS patients decreases the severity of obstructive sleep apnea by oxygen parameters on PSG. Palatal fistulas and relapse of respiratory distress are common complications of CP repair following MDO. Delaying CP repair may help to decrease complication rates.

Pulmonary Function Tests May Better Predict Dyspnea-Severity in Patients with Subglottic Stenosis Compared to Clinician-Reported Stenosis.

Patients with subglottic stenosis (SGS) present with varied degree of breathing complaints. The dyspnea index (DI) is a 10-question patient-reported outcome measure designed to measure the severity of upper airway obstruction. We set out to determine whether pulmonary function tests or clinician-reported degree of stenosis best predicted DI scores. Thirty patients with SGS were retrospectively reviewed over a 6-year period. One visit from each patient was included. Data including peak expiratory flow rate (PEFR), body-mass index (BMI), clinician-reported degree of stenosis, and DI scores were reviewed. Multiple linear regression was performed to determine how degree of stenosis and PEFR % predicted the variation in DI score. PEFR % better predicted DI scores compared to degree of stenosis (partial correlation -0.32 vs 0.17). After stepwise elimination, PEFR % remained in the regression and was significantly associated with DI scores (F[1, 29] = 9.38, P = .005). BMI did not demonstrate a linear relationship with DI scores and was not included in the regression (r = -.02). The PEFR % unstandardized coefficient was -0.25 (95% CI: -0.42 to -0.08, P = .005). The model predicts that a 4% increase in the PEFR % results in a 1-point decrease in the DI score (95% CI: -1.68 to -0.32). This study suggests that pulmonary function tests may be a better in-office measure to substantiate the severity of symptoms in patients with SGS.

Severity of Airway Obstruction May Not Correlate With Weight Gain or Failure to Thrive in Infants With Robin Sequence: A Pilot Study.

Patients with Robin sequence (RS) can present with varying degrees of upper airway obstruction, difficulty maintaining adequate weight gain, and failure to thrive (FTT). Although inductive reasoning would suggest that these issues should be interrelated, the relationships between these factors have not been formally studied. This investigation explores the correlation between polysomnographic (PSG) findings, weight gain, and FTT in patients with RS. A prospective database for baseline PSG parameters and serial weight measurements in infants with RS who were admitted for airway obstruction was reviewed. The association between PSG variables and calorie intake with FTT was assessed using univariate and multivariable logistic regression. Categorical analysis of the PSG variables against FTT was explored with a Poisson regression, and linear regression was performed to evaluate the correlation between PSG parameters and percentage of weight gain. Univariate and multivariate logistic regression in RS patients with (n = 13) and without (n = 20) FTT showed no significant association between apnea-hypopnea index (adjusted odds ratio [aOR]: 0.99, P-value = 0.403), O2 nadir (aOR: 0.98, P-value = 0.577), time of O2 saturation below 90% (aOR: 1.03, P-value = 0.574), maximum end tidal carbon dioxide (aOR: 1.0, P-value = 0.977), and average calorie intake (OR:1.02; P-value = 0.984). Furthermore, no significant associations were identified between these variables and weight gain. This pilot study questions the widely held and intuitively logical belief that poor weight gain and/or FTT should correlate with the severity of upper airway obstruction in patients with RS. Large prospective investigations should be initiated to better explore the authors' findings. Our results also underscore the importance of individualized treatment for these challenging patients.

Improvement in Snoring and Sleep Apnea after Adenotonsillectomy in Children of 3 To 10 Years of Age

Background: Variability is found about the severity of upper airway obstruction ranging from primary snoring to obstructive sleep apnea syndrome (OSAS). Adenotonsillectomy (AT) is taken as the primary treatment option. Objective: To evaluate the efficacy of Adenotonsillectomy among children having obstructive sleep apnea syndrome. Methodology: This was a cross-sectional study conducted at Bahawal Victoria Hospital Bahawalpur from January 2017 to January 2018. A total of 52 children of both genders, aged 3 to 10 years, having obstructive sleep apnea syndrome (OSAS) and selected for Adenotonsillectomy (AT) were enrolled. Adenotonsillectomy was performed in all the study participants employing general anesthesia. Preoperative and postoperative characteristics as well as respiratory and sleep parameters were compared adopting chi-square test for qualitative variables while t-test was employed for quantitative variables. Results: Out of a total of 52 children, 32 (61.5%) were male. The majority of the children, 27 (51.9%) were between 3-6 years of age. Statistically significant improvement (p-value < 0.05) was noted at the postoperative interval following AT for obstructive AHI score, respiratory disturbance index, obstructive apnea and hypopnea index, SpO2 nadir, TSpO2<90%, and respiratory arousal index. Obstructive AHI score < 1 episode / hour was seen in 37 (71.2%) children while AHI score < 5 episodes / hour were noted in 47 (90.4%). Conclusion: Adenotonsillectomy for obstructive sleep apnea syndrome improved quality of life and polysomnographic parameters in most of the children.

Comparison and intervention of differences in upper airway obstruction in children with OSAS between awake and asleep

Objective:Drug induced sleep endoscopy（DISE） is a useful tool to locate the upper airway obstructions in patients with obstructive sleep apnea syndrome（OSAS）. The goal of our research was to compare the sites, degree and patterns of upper airway obstruction detected by DISE versus endoscopy in awake children. The benefit of DISE-mediated upper airway surgery in pediatric OSAS was evaluated. Method:This is a retrospective case series of children with OSAS who had adenoid hypertrophy（the area where adenoids block the postnaris ≥2/3） and tonsils ≤2 degrees（Friedman classification method） . All children underwent sleep monitoring by pulse oximeter before and after operation. DISE was performed before adenoidectomy in DISE group. If obstruction of oropharynx caused by tonsils was found, tonsillectomy was performed at the same time with adenoidectomy. The children who did not undergo DISE before operation were enrolled in the control group. Differences in the degrees and patterns of upper airway obstruction in the DISE group under wakefulness and drug induction were analyzed. Result:The study included 126 children in DISE group, and 200 children in control group. In the DISE group, 56 cases（44.4%） had grade 2 tonsils, and 70 cases（55.6%） had grade 1 tonsils. The patterns of obstruction at velum, tongue base and epiglottis were significantly different in DISE compared with awake endoscopy（P<0.05）; the patterns of obstruction at adenoid and oropharynx were the same in both techniques. There were significant differences in endoscopy scores between the lateral wall of oropharynx and the tongue base（P<0.05）. DISE revealed 57 （45.2%） cases had grade 2 obstruction in the oropharyngeal level. Among them, 44 cases （34.9%） had tonsils at 2 degrees and 13 cases （10.3%） had tonsils at 1 degrees.. There was an improvement in respiratory disturbance index（RDI） and oxygen saturation nadir in the DISE and control groups 1 year after surgery（P<0.05）, and the RDI improvement was better in the DISE group compared with controls（P=0.04）. Conclusion:DISE is an effective method to evaluate the sites and severity of upper airway obstruction in children with OSAS, which was conductive to make the upper airway personalized surgical plan for patients.

Intranasal Leptin Prevents Opioid Induced Respiratory Depression in Obesity

IntroductionNorth America is currently facing obesity and opioid epidemics. Respiratory depression is the main cause of morbidity and mortality from opioids. Obese individuals with Obstructive Sleep Apnea have a higher risk of opioid induced respiratory depression (OIRD). Leptin acts as respiratory stimulant augmenting control of breathing and improving upper airway patency. We have previously shown that obesity‐induced leptin resistance can be circumvented by intranasal administration of leptin. In this study, we aimed to examine if intranasal administration of leptin prevents OIRD.MethodsMale diet‐induced obese C57BL/6J mice (n=8) were instrumented with headmount containing EEG and EMG leads under 1–2% isoflurane anesthesia. After recovery period polysomnograms were performed in a crossover manner with 1 week interval between studies. Mice received intranasal (IN) leptin or vehicle (BSA) at 0.4 mg/kg and 30 minutes later received a bolus of intraperitoneal (IP) morphine at 10 mg/kg followed by implantation of a subcutaneous osmotic pump delivering morphine at 2 mg/kg/h for the duration of the study (11am–5pm). The control group received IN vehicle, IP saline and a sham osmotic pump filled with saline. Minute ventilation (VE) was recorded through sleep/wake states and upper airway obstruction was defined by the presence of inspiratory flow limitation (IFL). Apneas were scored when flow was absent for two or more respiratory cycles. Excitatory post‐synaptic currents (EPSCs) were recorded in‐vitro from hypoglossal motor neurons (HGNs) and changes in EPSC amplitude and frequency were examined following application of the μ opioid receptor agonist (DAMGO) and leptin.ResultsMorphine induced severe inspiratory flow limitation and apneas during NREM sleep. Morphine increased IFL breath frequency (from 12% to 57% of all breaths, p&lt;0.001) and apneas (from 13.5±3.5/h to 91.5±20.0/h, p&lt;0.01) and decreased maximal inspiratory flow (VImax) during IFL breaths (from 3.4±0.4 to 2.3±0.4 mL/s, p&lt;0.05) and VE (from 1.1±0.1 to 0.7±0.2 mL/min/g, p&lt;0.05). Leptin attenuated effects of morphine. IN Leptin decreased IFL breath frequency (from 57% to 45%, p&lt;0.005) and reduced the number of apneas (from 91.5±20.0/h to 34.3±7.0/h, p&lt;0.01). Leptin reduced the severity of upper airway obstruction increasing VImax (from 2.3±0.4 to 2.8±0.4, p&lt;0.05) and minute ventilation (from 0.7±0.2 to 1.0±0.2, p&lt;0.05) during IFL breathing. Furthermore, in vitro studies showed that administration of DAMGO reduced EPSC frequency (but not EPSC amplitude) in HGNs that was reversed by application of leptin.ConclusionMorphine caused respiratory suppression and upper airway obstruction during sleep in DIO mice and decreased EPSC frequency in HGNs. Leptin relieved morphine‐induced hypoventilation and Obstructive Sleep Apnea and reversed the opioid induced depression of excitatory synaptic neurotransmission to HGNs. We conclude that intranasal leptin may prevent OIRD in obesity.Support or Funding InformationR01HL 128970, R01HL 138932, FAPESP 2018/08758‐3

Assessment of upper airway obstruction in children with specific learning disorder

Aim: A growing number of findings suggest that there is an important relationship between upper airway obstruction (UAO) and specific learning disorder (SLD). However, existing evidence is limited to very few studies. We, thus, aimed to explore chronic UAO conditions in children with specific learning disabilities.Materials and Methods: This study involved seventy-seven children aged 7 to 10 years with SLD and eighty-six healthy children matching in age and gender. Psychiatric disorders were diagnosed through the Diagnostic and Statistical Manual of Mental Disorders (DMS-5) Criteria. Porteus Maze Test and Kent-EGY test were used to assess the intelligence of the participants. The diagnoses of UAO were made by a physical examination, a detailed otorhinolaryngologic examination, the anamnesis and clinical history, anterior rhinoscopy, and flexible endoscopic nasopharyngoscopy according to the type of UAO.Results: The rates of having at least one pathology causing UAO and secondary sleep difficulties due to UAO were significantly higher in children with SLD compared to controls. The severity of SLD was significantly associated with the severity of UAO and the presence of secondary sleep difficulties, but not the presence of UAO. The verbal and total IQ scores were significantly affected by the presence and severity of UAO, while the presence of secondary sleep difficulties significantly impacted all IQ scores.Conclusion: Parents, teachers, otorhinolaryngologists, child psychiatrists, and pediatricians should be aware that the association between learning disorders and UAO. It also would be advisable to screen children with learning disorders in terms of UAO, and vice versa.

Clinical assessment and related intervention of neonatal upper airway obstruction

Objective:To discuss the diagnosis and evaluation of upper airway obstruction in neonates, classify the possible causes of neonatal upper airway obstruction, establish a standardized diagnosis and treatment procedure to improve the of treatment efficacy. Method:Clinical data of 71 cases with upper airway obstruction history were retrospective analyzed, 38 cases were treated by combined medical and surgical treatment, 17 cases underwent medical treatment, 16 cases abandonment the treatment. The effectiveness of fibrolaryngoscope, CT, neck ultrasound, MRI and other results was evaluated, and to analyze the prognosis of the treatment, the outcomes and risk factors were also analysed, to evaluate risk factors associated with upper airway obstruction. Result:Fifty-five cases were cured or improved. The mortality rate of 16 children who gave up treatment and left hospital automatically was 81.25%（13/16）. The accuracy rate of flexible laryngoscope in detecting the level of upper airway obstruction was 100%, the coincidence rate of B-ultrasound for upper airway cystic occupation was 100%. Etiological order from high to low was congenital space-occupying lesions, congenital upper airway malformation, vocal cord paralysis, Pierre-Robin syndrome. The site of obstruction has a significant influence on the severity of upper airway obstruction（P<0.05）. The cure rate of the non-endotracheal intubation group was higher than that of the endotracheal intubation group（P<0.05）. Conclusion:The obstruction site of upper airway significantly affects the outcome and the severity of the disease. Upper airway space occupying lesions are the primary causes of upper airway obstruction in neonates. Early assessment and timely treatment can improve the cure rate and improve the prognosis. Internal medicine combined with surgical treatment is effective in relieving upper airway obstruction.

Efficacy of Upper Gastrointestinal Endoscopic Examination to Identify Patients with Obstructive Sleep Apnea Syndrome: A Retrospective Cross-Sectional Study

Background/Aims: Despite the high prevalence of obstructive sleep apnea syndrome (OSAS), most individuals are unaware of its diagnosis. We assessed whether an upper gastrointestinal (GI) endoscopy can accurately predict the incidence of OSAS. Methods: After endoscopic evaluation of laryngo-pharyngeal collapse, a total of 154 subjects with laryngo-pharyngeal collapse and 52 control subjects underwent polysomnography. Based on the modified Fujita Classification, upper airway obstruction was classified into 3 different types: oropharyngeal, supraglottic and combined type, and associations between upper airway obstruction and OSAS were evaluated. Results: Of 154 subjects with laryngo-pharyngeal collapse, 108 (70.1%) were diagnosed as OSAS, while only 4 (7.7%) control subjects were diagnosed as OSAS (p < 0.001). The sensitivity and specificity of endoscopic diagnosis were 96.4 and 51.1%, respectively. Oropharyngeal involvement was frequently found in 90.2% of the subjects (139/154). The severity of upper airway obstruction was significantly correlated with the apnea-hypopnea index score (r = 0.55, p < 0.001). A multivariate logistic regression analysis revealed that a male sex (OR 5.20; 95% CI 2.65–10.2, p < 0.001), body mass index ≥25 kg/m² (OR 4.98; 95% CI 2.23–11.2, p = 0.02) and severe obstruction (OR 7.79; 95% CI 3.34–18.2, p < 0.001) were significant independent predictors of severe OSAS. Conclusion: A conventional upper GI endoscopic examination might be useful as a diagnostic modality for OSAS.

Is Peripheral Oxygen Saturation a Reliable Predictor of Upper Airways Air-Flow Limitation?

BackgroundDyspnea secondary to acute upper airways airflow limitation (UAAFL) represents a clinical emergency that can be difficult to recognize without a suitable history; even when etiology is known, parameters to assess the severity are unclear and often improperly used. ObjectivesThe aim of this study was to assess the role of peripheral oxygen saturation (SpO2) as a predictor of severity of upper airway obstruction. MethodsThe authors propose an experimental model of upper airway obstruction by a progressive increase of UAAFL. Ten healthy volunteers randomly underwent ventilation for 6 min with different degrees of UAAFL. SpO2, heart rate, respiratory rate (RR), tidal volume, accessory respiratory muscle activation, and subjective dyspnea indexes were measured. ResultsIn this model, SpO2 was not reliable as the untimely gravity index of UAAFL. Respiratory rate, visual analogue scale (VAS), and Borg dyspnea scale were statistically correlated with UAAFL (p < 0.0001 for RR and p < 0.05 for VAS and Borg scale). No significant changes were observed on heart rate (p > 0.05) and tidal volume (p > 0.05); a RR ≤ 7 breaths/min; VAS and Borg scale showed statistically significant parameters changes (p < 0.05). ConclusionsRR, VAS, and Borg dyspnea scales are sensitive parameters to detect and stage, easily and quickly, the gravity of an upper airways impairment, and should be used in emergency settings for an early diagnosis of a UAAFL. SpO2 is a poorer predictor of the degree of upper airways flow limitation.

Hypoventilation disproportionate to OSAS severity in children with Prader-Willi syndrome

ObjectiveTo test the hypothesis that children with Prader-Willi syndrome (PWS) and obstructive sleep apnoea syndrome (OSAS) have hypercapnia for higher proportion of total sleep time (TST) than non-syndromic children with...

The Impact of Enzyme-Replacement Therapy on Upper Airway Obstruction in Children with Mucopolysaccharidoses: Retrospective Cohort Study

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Peak inspiratory flow as predictor for tracheotomy

ObjectivesQuantitative evaluation of upper airway obstruction cannot be commonly performed under acute dyspnea, especially in head and neck cancer (HNC); the decision whether or not to perform airway control surgery may be difficult to reach. Peak inspiratory flow (PIF) has been previously demonstrated to be a useful tool to decide on decannulation after HNC surgery. The aim of the present study was to assess the role of PIF as a standardized non-invasive tool in quantifying severe inspiratory dyspnea requiring emergency tracheostomy. Materials and methodsA single-center prospective observational pilot study analyzed PIF measurements in 22 patients exhibiting acute dyspnea due to upper airway obstruction. Main outcome measuresThe decision whether or not to perform tracheotomy was taken prior to PIF measurement. PIF was measured with a hand-held PIF meter (In-Check method), and laryngeal fiberoscopy was then performed. Obstruction severity was defined by PIF values. ResultsPIF could be measured prior to tracheotomy (imminent in 21 cases, postponed in 1) in all cases. PIF values below 53.1 L/min (i.e., 18.3% of theoretic value) correlated with necessity for emergency tracheotomy. This threshold is concordant with that previously found for the feasibility of decannulation (60L/min). ConclusionsPIF is a non-invasive quantitative parameter assessing severity of upper airway obstruction, that may be helpful in decision-making for tracheostomy. Testing is simple, quick and reproducible.

Utilizing inspiratory airflows during standard polysomnography to assess pharyngeal function in children during sleep.

Obstructive sleep apnea (OSA) is the result of pharyngeal obstruction that occurs predominantly during REM in children. Pathophysiologic mechanisms responsible for upper airway obstruction, however, are poorly understood. Thus, we sought to characterize upper airway obstruction in apneic compared to snoring children during sleep. We hypothesized that apneic compared to snoring children would exhibit an increased prevalence and severity of upper airway obstruction, that would be greater in REM compared to non-REM, and would improve following adenotonsillectomy. Apneic children were assessed with routine polysomnography before and after adenotonsillectomy, and compared to snoring children matched for gender, age, and BMI z-score. In addition to traditional scoring metrics, the following were used to characterize upper airway obstruction: maximal inspiratory airflow (%VI max) and percent of time with inspiratory flow-limited breathing (%IFL). OSA compared to snoring children had similar degrees of upper airway obstruction in non-REM; however, during REM, children with sleep apnea exhibited a higher %IFL (98 ± 2% vs.73 ± 8%, P < 0.01) and lower %VI max (56 ± 6 vs.93 ± 10%, P < 0.01). In children with OSA, CO2 levels were elevated during both wake and sleep. Following adenotonsillectomy, upper airway obstruction improved during REM manifest by decreased %IFL (98 ± 2 to 63 ± 9%, P = 0.04), increased %VI max (56 ± 6 to 95 ± 5%, P = 0.01) and decreased CO2 levels. Differences in the prevalence and severity upper airway obstruction suggest impaired compensatory responses during REM in children with OSA, which improved following adenotonsillectomy.

The effect of leptin replacement on sleep-disordered breathing in the leptin-deficient ob/ob mouse.

Obese leptin-deficient (ob/ob) mice demonstrate defects in upper airway structural and neuromuscular control. We hypothesized that these defects predispose to upper airway obstruction during sleep, and improve with leptin administration. High-fidelity polysomnographic recordings were conducted to characterize sleep and breathing patterns in conscious, unrestrained ob/ob mice (23 wk, 67.2 ± 4.1 g, n = 13). In a parallel-arm crossover study, we compared responses to subcutaneous leptin (1 μg/h) vs. vehicle on respiratory parameters during NREM and REM sleep. Upper airway obstruction was defined by the presence of inspiratory airflow limitation (IFL), as characterized by an early inspiratory plateau in airflow at a maximum level (V̇Imax) with increasing effort. The severity of upper airway obstruction (V̇Imax) was assessed along with minute ventilation (V̇E), tidal volume (VT), respiratory rate (RR), inspiratory duty cycle, and mean inspiratory flow at each time point. IFL occurred more frequently in REM sleep (37.6 ± 0.2% vs. 1.1 ± 0.0% in NREM sleep, P < 0.001), and leptin did not alter its frequency. V̇Imax (3.7 ± 1.1 vs. 2.7 ± 0.8 ml/s, P < 0.001) and V̇E increased (55.4 ± 22.0 vs. 39.8 ± 16.4 ml/min, P < 0.001) with leptin vs. vehicle administration. The increase in V̇E was due to a significant increase in VT (0.20 ± 0.06 vs. 0.16 ± 0.05 ml, P < 0.01) rather than RR. Increases in V̇E were attributable to increases in mean inspiratory flow (2.5 ± 0.8 vs. 1.8 ± 0.6 ml/s, P < 0.001) rather than inspiratory duty cycle. Similar increases in V̇E and its components were observed in non-flow-limited breaths during NREM and REM sleep. These responses suggest that leptin stabilized pharyngeal patency and increased drive to both the upper airway and diaphragm during sleep.

Surgical versus nonsurgical interventions to relieve upper airway obstruction in children with Pierre Robin sequence.

Newborns with Pierre Robin sequence (PRS) often experience chronic intermittent hypoxemia/hypoventilation associated with airway obstruction. The heterogeneity of the severity of upper airway obstruction makes management a challenge; the optimal intervention in individual cases is not clear. To investigate the prevalence of surgical/nonsurgical interventions for PRS at two children's hospitals. Patient characteristics and outcomes were examined. The present retrospective chart review identified 139 patients with PRS born between 2000 and 2010. Demographic information, mode of airway management, associated anomalies and syndromes, polysomnography results, length of intensive care unit and hospital stay, complications and deaths were extracted. Interventions included prone positioning (alone [61%]), tongue-lip adhesion (45%), nasopharyngeal intubation (28%), continuous positive airway pressure (20%), tracheostomy (19%) and mandibular distraction osteogenesis (5%). Tracheostomies were more prevalent in syndromic patients (P=0.03). Patients who underwent tracheostomy had a lower birth weight (P=0.03) compared with newborns with other interventions. Patients who underwent surgical interventions had longer intensive care unit stays (P<0.001). No intervention was associated with a statistically significant likelihood of requiring a subsequent intervention. Thirty percent of patients underwent polysomnography, with a higher proportion of these using continuous positive airway pressure (n=15) (P<0.01). In the present descriptive study, patients with syndromic PRS or low birth weight underwent early intervention, which included a tracheostomy. Objective measures of airway obstruction were underutilized. Decision making regarding evaluation and management of upper airway obstruction in this population remains clinician and resource dependent. Reporting data obtained from a large cohort of PRS patients is important to compare experiences and motivate future studies investigating this complex condition.

Characterization of Upper Airway Obstruction by Fiber-Optic Nasolaryngoscopy and MRI in Preoperative OSAHS Patients

Objective: To investigate changes in the upper airway and its surrounding soft tissue and to characterize the extent and severity of upper airway obstruction in 136 obstructive sleep apnea/hypopnea syndrome (OSAHS) patients who were awake. Methods: OSAHS patients and healthy controls were evaluated by fiber-optic nasolaryngoscopy and MRI. The cross-sectional area and pharyngeal wall thickness of the retropalatal, retroglossal and epiglottic region were determined. Results: Ninety-five percent of the mild OSAHS subjects had single-plane obstruction (vs. severe OSAHS, p < 0.05), 5.0% of the mild OSAHS subjects had two-plane obstruction (p < 0.05) and none of them had three-plane obstruction (p < 0.05). The cross-sectional area of the retropalatal, retroglossal and epiglottic region progressively declined as the severity of OSAHS increased (severe OSAHS vs. controls, p < 0.05). The lateral pharyngeal wall was significantly thicker in OSAHS subjects than in healthy controls (p < 0.05). The cross-sectional area of the soft palate in moderate and severe OSAHS subjects was markedly larger than that of the healthy controls (p < 0.05) and positively correlated with the apnea/hypopnea index (p < 0.05). Conclusion: Moderate and severe OSAHS patients exhibit multi-plane obstruction of the upper airway, particularly in the retropalatal and retroglossal region. The severity of OSAHS negatively correlates with the thickness, length and cross-sectional area size of the soft palate.