Alveolar Hypoventilation Research Articles

Average volume-assured pressure support versus fixed pressure support in chronic hypercapnic respiratory failure: a systematic review and meta-analysis

Rationale: Chronic hypercapnic respiratory failure occurs due to alveolar hypoventilation resulting in carbon dioxide retention. This is commonly managed with noninvasive ventilation (NIV) with modalities including fixed pressure support and average volume-assured pressure support (AVAPS). However, there is limited information comparing outcomes with these two modes of ventilator support in the management of chronic hypercapnic respiratory failure. Objective: This review and meta-analysis analyze the outcomes with fixed pressure NIV versus average volume-assured pressure support NIV in managing chronic obstructive pulmonary disease (COPD) with chronic hypercapnic respiratory failure, focusing on patients’ perception of symptom burden and gas exchange based on arterial blood gases. Search methods: PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science databases were searched; the latest search date was December 1, 2023. Inclusion criteria: randomized control trials and crossover studies in English in adults over the age of 19 with the diagnosis of COPD and chronic hypercapnic respiratory failure. Exclusion criteria: patients less than 19 years old, patients with acute exacerbations, and patients with central respiratory failure or neuromuscular disease. Outcomes included blood gas analysis after use of NIV measured in mmHg and patient perception of mental health, symptom burden, and comfort. Results for each outcome were analyzed in RevMan using an inverse variance statistical method with a fixed effect analysis. The final analysis included 7 studies with 252 participants. Results: The patients were 64 ± 9 years old. Baseline pulmonary function testing showed a forced expiratory volume in the first second (FEV1) of 34.6 ± 14.2 % predicted, consistent with severe COPD per GOLD criteria, and a baseline PaCO2 of 55.2 ± 9.2 mmHg. Primary outcomes for ventilation showed no statistical difference between AVAPS and fixed pressure support groups in PaCO2 (Odds Ratio [OR] -1.51; 95% Confidence Interval [CI]: -3.18, 0.16; p=0.08). Patient perceived outcomes were evaluated using several questionnaires, including St. George Respiratory Questionnaire (SGRQ), Short Form 36 Health Survey Questionnaire (SF-36), and Visual Analogue Scale (VAS). Comparable results were not available for all studies, but no statistically significant differences were found when comparing study results. Conclusions: There was little or no clinically significant difference between fixed pressure support and AVAPS in gas exchange. There are inadequate data to draw conclusions about the effect of fixed pressure support compared to AVAPS on patient perceived outcomes, such as comfort and symptom burden. No studies evaluated mortality benefit, cost effectiveness, or hospitalizations. Key words: COPD, chronic hypercapnic respiratory failure, non-invasive ventilation, average volume-assured pressure support ventilation

High-Flow Nasal Oxygen in Patients with Acute Hypercapnic Respiratory Failure: A Narrative Review of the Physiological Rationale and Clinical Evidence.

Acute hypercapnic respiratory failure is a life-threatening condition caused by alveolar hypoventilation. It is mostly caused by an acute exacerbation of chronic obstructive pulmonary disease or conditions yielding muscle dysfunction. Noninvasive ventilation through a facemask is the cornerstone first-line strategy to support hypercapnic patients with acidemia, and current guidelines strongly recommend this intervention to improve survival and long-term clinical outcomes. Because of its benefits related to carbon dioxide washout from the upper airways and the enhanced comfort, high-flow nasal oxygen has been proposed as a respiratory support strategy in patients with hypercapnic respiratory failure, both as an alternative to and in combination with noninvasive ventilation. When compared to noninvasive ventilation as a first-line intervention, high-flow nasal oxygen shows a higher rate of failure. Hence, if not contraindicated, the use of noninvasive ventilation should be preferred. After the resolution of acidemia with noninvasive ventilation, high-flow nasal oxygen showed promising physiological effects compared to conventional oxygen. During weaning from mechanical ventilation in patients with or at risk of developing hypercapnia, high-flow nasal oxygen showed encouraging results, especially when applied alternating with sessions of noninvasive ventilation. Optimal settings of high-flow nasal oxygen in hypercapnic patients include the use of a smaller-size cannula, flows ranging between 30 and 40 L/min, and FiO2 adjusted to obtain SpO2 between 88% and 92%. Specific interfaces, such as asymmetric cannulas, may further enhance the benefits of a high flow in terms of carbon dioxide clearance. In this narrative review, we provide an updated overview of the physiological rationale and clinical evidence concerning the use of high-flow nasal oxygen in patients with acute hypercapnic respiratory failure.

Obesity Hypoventilation (Pickwickian) Syndrome – ”The Tip of an Iceberg” in Morbidly Obese Patients

ABSTRACT Obesity hypoventilation syndrome (OHS), also known as Pickwickian syndrome, is a combination of obesity (body mass index (BMI) >30 kg/m2), daytime hypercapnia (arterial carbon dioxide tension >45 mm Hg) and sleep-disordered breathing, after exclusion of other disorders that may cause alveolar hypoventilation. Management of OHS requires a multifaceted approach in the form of weight loss, treatment of existing co-illnesses, pulmonary rehabilitation, and Bi-level positive airway pressure (Bi-PAP) therapy. A 58-year-old lady with a BMI of 50 kg/m2 with symptoms of obstructive sleep apnea (OSA) and OHS presented to the hospital with respiratory distress. She gave a history of breathlessness, snoring, and sleep disturbances for the last 7 years. She was managed by a physician with a diagnosis of obstructive airway disease without further evaluation of sleep disturbance. On admission, she was started on non-invasive ventilation during her initial management. After 72 hours of admission, the patient became stable, and overnight polysomnography was performed to confirm the diagnosis of OHS. After confirmation of the diagnosis, she was started on Bi-PAP therapy along with other supportive therapy for 7 days. She was discharged after 10 days of admission with nocturnal Bi-PAP therapy at home and was enrolled in a comprehensive pulmonary rehabilitation program. Patient is on regular follow-up and has been doing well since then.

Autism spectrum disorder in young patients with congenital central hypoventilation syndrome: role of the autonomic nervous system dysfunction

BackgroundCongenital central hypoventilation syndrome (CCHS) is a rare condition characterized by alveolar hypoventilation and autonomic nervous system (ANS) dysfunction requiring long-term ventilation. CCHS could constitute a risk factor of autism spectrum disorder (ASD) due to birth injury related to respiratory failure, which remains to be determined. ANS dysfunction has also been described in ASD and there are indications for altered contribution of ANS-central nervous system interaction in processing of social information; thus, CCHS could be a risk factor for ASD based on pathophysiological background also. Our study aimed to determine the prevalence of ASD among CCHS patients, identify risk factors, and explore the relationship between the ANS, evaluated by heart rate variability indices, and adaptative functioning.ResultsOur retrospective study, based on the analysis of records of a French national center of patients with CCHS under 20 years of age, determined that the prevalence of ASD (diagnosed by a psychiatrist, following the criteria of DSM-4 or DSM-5) was 6/69 patients, 8.7% (95% confidence interval: 3.3–18.0%). In a case (CCHS with ASD, n = 6) – control (CCHS without ASD, n = 12) study with matching on sex, longer neonatal hospitalization stay and glycemic dysfunction were associated with ASD. Adaptative functioning was assessed using Vineland Adaptative behavioral scales (VABS) and heart rate variability indices (including daytime RMSSD as an index of parasympathetic modulation) were obtained from ECG Holter performed the same day. In 19 young subjects with CCHS who had both ECG Holter and VABS, significant positive correlations were observed between RMSSD and three of four sub-domains of the VABS (communication: R = 0.50, p = 0.028; daily living skills: R = 0.60, p = 0.006; socialization: R = 0.52, p = 0.021).ConclusionOur study suggests a high prevalence of ASD in patients with CCHS. Glycemic dysfunction and longer initial hospitalization stays were associated with ASD development. A defect in parasympathetic modulation was associated with worse adaptative functioning.

Respiratory management of acute chest syndrome in children with sickle cell disease.

Acute chest syndrome (ACS) is a leading cause of respiratory distress and hospitalisation in children with sickle cell disease (SCD). The aetiology is multifactorial and includes fat embolism, venous thromboembolism, alveolar hypoventilation and respiratory infections, with the latter being particularly common in children. These triggers contribute to a vicious cycle of erythrocyte sickling, adhesion to the endothelium, haemolysis, vaso-occlusion and ventilation-perfusion mismatch in the lungs, resulting in the clinical manifestations of ACS. The clinical presentation includes fever, chest pain, dyspnoea, cough, wheeze and hypoxia, accompanied by a new pulmonary infiltrate on chest radiography. Respiratory symptoms may overlap with those of acute asthma, which may be difficult to distinguish. Patients with ACS may deteriorate rapidly; thus prevention, early recognition and aggressive, multidisciplinary team management is essential. In this narrative review, we highlight the current evidence regarding the epidemiology, pathophysiology, treatment and preventative strategies for ACS, focusing on the aspects of major interest for the paediatric pulmonologist and multidisciplinary team who manage children with SCD.

Screening Strategies for Sleep-Disordered Breathing in Patients With Spinal Cord Injury in a Tertiary Care Rehabilitation Center.

Sleep-disordered breathing (SDB) is frequent in patients with spinal-cord injury (SCI). However, SDB is frequently underdiagnosed due to limited access to diagnostic testing and knowledge about the condition. Moreover, SDB heterogeneity (sleep apnea, obstructive sleep apnea or central sleep apnea and nocturnal alveolar hypoventilation) implies complex evaluation of both nocturnal respiratory effort and hypercapnia. The aim of this study was to compare different screening strategies for an SDB diagnosis in patients with SCI. This was a retrospective analysis of data from subjects with SCI followed up in a tertiary-care rehabilitation center with a specialized sleep unit. Subjective (questionnaires) and objective data (polysomnography [PSG]), [Formula: see text] extracted from the PSG, morning blood gases, and nocturnal transcutaneous CO2 (PtcCO2 ) were collected and analyzed. A retrospective comparison of different strategies for SDB screening was carried out. Each strategy was compared (alone and in combination) with the standard of care for sleep apnea (PSG) and nocturnal alveolar hypoventilation (PtcCO2 ) diagnosis. The performance of the usual cutoff and visual analysis was studied. Among 190 subjects with SCI who underwent a full night's PSG, data were available for 104 questionnaires and 162 with oximetry. Nocturnal alveolar hypoventilation was screened by PtcCO2 and blood gases in 52 subjects with SCI. Questionnaires (the modified Screening for Obstructive Sleep Apnea in Tetraplegia and the Epworth Sleepiness Scale) had poor performance for identifying sleep apnea and did not identify nocturnal alveolar hypoventilation. [Formula: see text] (oxygen desaturation index score ≥ 13) and visual analysis of [Formula: see text] were good at identifying sleep apnea but insufficient to identify nocturnal alveolar hypoventilation. Diurnal blood gases were poor predictors of nocturnal alveolar hypoventilation. Questionnaires were of limited use in subjects with SCI, but the oxygen desaturation index derived from oximetry performed well for sleep apnea screening. Both diurnal blood gases and oximetry visual analysis were insufficient for nocturnal alveolar hypoventilation screening. PtcCO2 monitoring should be mandatory and ideally combined with PSG given the heterogeneity of SDB phenotypes and associated sleep comorbidities of patients with SCI.

Management of sleep-disordered breathing in patients with syndromic hemifacial macrosomia.

Patients with syndromic hemifacial microsomia (SHFM) are at risk of obstructive sleep apnea (OSA). The aim of the study was to describe the prevalence of OSA and its management, especially in patients with Goldenhar syndrome (GS). The respiratory polygraphies and clinical management of 15 patients, aged 2 to 23years, evaluated at a national reference center, were analyzed. Four (27%) patients had no OSA, 4 (27%) had mild OSA, and 7 (46%), of whom 5 were ≤ 2years old, had severe OSA. None of the patients had central apneas. Only one patient had alveolar hypoventilation, and another one had nocturnal hypoxemia. Two patients had severe OSA despite prior adenoidectomy or mandibular distraction osteogenesis. Median duration of follow-up was 3.5years (range 0.5-9years). None of the patients without OSA or with mild OSA at baseline respiratory polygraphy developed OSA during the follow up. Among the 7 patients with severe OSA, 3 required continuous positive airway pressure or noninvasive ventilation, and one patient required a tracheostomy. In conclusion, patients with SHFM are at high risk of severe OSA at any age, underlining the importance of systematic sleep studies to diagnose and evaluate the severity of OSA. Individualized treatment should be privileged, based on a careful examination of the entire upper airway, taking in account potential associated risk factors. All patients with SHFM should be managed by a pediatric expert multidisciplinary medical/surgical team until the end of post pubertal growth.

Prevalence, Severity, and Treatment of Obstructive Sleep Apnea in Children with Down Syndrome in Qatar.

Patients with Down syndrome (DS) are at risk for sleep disorder breathing (SDB) due to their abnormal craniofacial anatomy, hypotonia, and propensity for obesity. The prevalence and severity of SDB in this population vary between different cohorts due to the multifactorial nature of these patients and the different diagnostic criteria used. We aim to report the prevalence and severity of SDB in the DS population in Qatar. This study is a retrospective review of all patients with genetically confirmed DS who completed a diagnostic polysomnography (PSG) study at Sidra Medicine in Doha, Qatar, which is the only pediatric sleep center in the country, between September 2019 and July 2022. Clinical and PSG data were collected from the patients' electronic medical records. Central and obstructive events were scored according to the American Academy of Sleep Medicine (AASM) criteria. Obstructive sleep apnea (OSA) diagnosis was made based on apnea-hypopnea index (AHI) and defined as AHI>1.5 events/hour.OSA was considered mild if AHI was ≥ 1.5 but < 5, moderate if AHI was ≥ 5 but < 10, and severe if AHI was ≥ 10 events/hour. Diagnosis with central apnea was considered if the central apnea index was > 5 events/hour. Hypoventilation was considered present if end-tidal/transcutaneous carbon dioxide gas was more than 50 mmHg for more than 25% of total sleep time.Multiple regression analysis was performed to evaluate predictors of high AHI and rapid eye movement (REM)-AHI. A total of 80 patients (49 males and 31 females) were included. Median (range) age was 7.3 years (0.9, 21). The mean (range) BMI z-score was 1.7 (-1.3, 4.3). Sixty-five patients were diagnosed with OSA, with a prevalence rate of 81%. OSA was mild in 25 (38.5%) patients, moderate in 15 (23.1%) patients, and severe in 25 (38.5%) patients. Only one patient was diagnosed with central apnea and five patients (6.9%) with alveolar hypoventilation. Multiple regression analysis showed BMI (P = 0.007) and snoring/apnea symptoms (P=0.023) to be predictive of high AHI. No correlation was found between the same variables and REM-AHI. Treatments used for OSA included anti-inflammatory medications in 37 (46%) patients, tonsillectomy/adenoidectomy in 13 (16.5%) patients, and positive airway pressure support in 10 (15%) patients. Our patient population with DS had a high prevalence of OSA comparable to other reported cohorts. High BMI and symptoms of snoring are predictive of OSA.

Congenital Central Hypoventilation Syndrome: neonatal diagnosis and management

To report a neonatal case successfully treated with non-invasive ventilatory support (NVS), avoiding tracheostomy. Full-term newborn, whose mother uses nocturnal NVS due to CCHS. During the transition period, she presented desaturations associated with hypercapnia and respiratory acidosis, without pulmonary involvement. She developed severe hypoventilation during sleep, with no respiratory effort, peripheral oxygen saturation (SpO2) < 80%, plus respiratory acidosis. While awake, she had good respiratory effort and normal SpO2 without assistance. Noninvasive continuous positive airway pressure and oxygen therapy worsened her condition while sleeping. Complete NVS with nasal interface and bi-level airway positive pressure, inspiratory/expiratory pressure 14-16/4 cm H2O, normalized SpO2 during sleep, and arterial blood gases while awake. Sequencing of the PHOX2B gene confirmed the presence of a heterozygous pathogenic variant with the 20/26 genotype. At 2 months of age, she was discharged maintaining NVS with nasal interface and 0 PEEP, achieving adequate neurodevelopment. We highlight the importance of genetic diagnosis of CCHS in neonates with clinical presentation of early alveolar hypoventilation, especially if there is a family history. We are not aware of other reports of neonatal onset in which NVS prevents IMV, in this potentially lethal pathology.

Gas exchange parameters for the prediction of obstructive sleep apnea in infants.

Sleep laboratory polysomnography is the gold standard for obstructive sleep apnea (OSA) diagnosis in infants, but its access remains limited. Oximetry-capnography is another simple and widely used tool that can provide information on the presence of desaturations and alveolar hypoventilation. However, its reliability is debated. This study aimed at examining its use in determining OSA severity in infants. This retrospective study was conducted in a sleep unit in a tertiary hospital in infants < 4 months old with clinical signs of OSA or Pierre Robin sequence who underwent a 1-night polysomnography coupled with oximetry-capnography. Among the 78 infants included (median [interquartile range] age: 61 [45-89] days at polysomnography), 44 presented with Pierre Robin sequence and 34 presented with isolated airway obstruction. The clinical, sleep, and respiratory characteristics were not significantly different between the 2 subgroups. In the entire cohort, 63.5% had severe OSA. The median obstructive apnea-hypopnea index was 14.5 (7.4-5.9) events/h, peripheral oxygen saturation (SpO2) was 97.4% (96.5-98.1%), and transcutaneous carbon dioxide pressure (PtcCO2) was 41.1 mmHg (38.3-44.9). The optimal threshold to predict an obstructive apnea-hypopnea index > 10 events/h was 6 events/h for an oxygen desaturation index ≥ 3% (sensitivity, 95.7%; specificity, 51.9%) and 2 events/h for an oxygen desaturation index ≥ 4% (sensitivity, 95.7%; specificity, 48.1%). Whereas transcutaneous capnography does not appear to be sufficient in predicting severe OSA in infants < 4 months old with Pierre Robin sequence or clinical signs of OSA, oximetry may be a useful alternative for the screening of severe OSA in infants in the absence of polysomnography. Gyapay R, Ioan I, Thieux M, etal. Gas exchange parameters for the prediction of obstructive sleep apnea in infants. J Clin Sleep Med. 2024;20(7):1059-1067.

Unraveling the mystery: a Mendelian randomized exploration of gut microbiota and different types of obesity.

Numerous studies have demonstrated the influence of gut microbiota on the development of obesity. In this study, we utilized Mendelian randomization (MR) analysis to investigate the gut microbiota characteristics among different types of obese patients, aiming to elucidate the underlying mechanisms and provide novel insights for obesity treatment. Two-sample multivariable Mendelian randomization (MR) analysis was employed to assess causal relationships between gut microbiota and various obesity subtypes. Gut microbiota data were obtained from the international consortium MiBioGen, and data on obese individuals were sourced from the Finnish National Biobank FinnGen. Eligible single-nucleotide polymorphisms (SNPs) were selected as instrumental variables. Various analytical methods, including inverse variance weighted (IVW), MR-Egger regression, weighted median, MR-RAPS, and Lasso regression, were applied. Sensitivity analyses for quality control included MR-Egger intercept tests, Cochran's Q tests, and leave-one-out analyses and others. Mendelian randomization studies revealed distinct gut microbiota profiles among European populations with different obesity subtypes. Following multivariable MR analysis, we found that Ruminococcaceae UCG010 [Odds Ratio (OR): 0.842, 95% confidence interval (CI): 0.766-0.926, Adjusted P value: 0.028] independently reduced the risk of obesity induced by excessive calorie intake, while Butyricimonas [OR: 4.252, 95% CI: 2.177-8.307, Adjusted P value: 0.002] independently increased the risk of medication-induced obesity. For localized adiposity, Pasteurellaceae [OR: 0.213, 95% CI: 0.115-0.395, Adjusted P value: <0.001] acted as a protective factor. In the case of extreme obesity with alveolar hypoventilation, lactobacillus [OR: 0.724, 95% CI: 0.609-0.860, Adjusted P value: 0.035] reduced the risk of its occurrence. Additionally, six gut microbiota may have potential roles in the onset of different types of obesity. Specifically, the Ruminococcus torques group may increase the risk of its occurrence. Desulfovibrio and Catenabacterium may serve as protective factors in the onset of Drug-induced obesity. Oxalobacteraceae, Actinomycetaceae, and Ruminiclostridium 9, on the other hand, could potentially increase the risk of Drug-induced obesity. No evidence of heterogeneity or horizontal pleiotropy among SNPs was found in the above studies (all P values for Q test and MR-Egger intercept > 0.05). Gut microbiota abundance is causally related to obesity, with distinct gut microbiota profiles observed among different obesity subtypes. Four bacterial species, including Ruminococcaceae UCG010, Butyricimonas, Pasteurellaceae and lactobacillus independently influence the development of various types of obesity. Probiotic and prebiotic supplementation may represent a novel approach in future obesity management.

Recruitment of inspiratory muscles according to the different stages of sleep in amyotrophic lateral sclerosis is a reliable indicator of the evolution of alveolar hypoventilation

Recruitment of inspiratory muscles according to the different stages of sleep in amyotrophic lateral sclerosis is a reliable indicator of the evolution of alveolar hypoventilation

Sleep disordered breathing assessment in patient with slowly progressive neuromuscular disease

BackgroundSleep-disordered breathing (SDB) is common in patients with neuromuscular diseases (NMD). Focusing on hypercapnia may lead to the neglect of other SDB such as obstructive and/or central sleep apnea syndrome (SAS). Our objectives were to assess the risk of inappropriate SDB management according to different screening strategies and to evaluate the prevalence and determinants of isolated and overlapping sleep apnea in patients with slowly progressive NMD. MethodsThis monocentric, cross-sectional, retrospective study analyzed medical records of adult NMD patients referred to a sleep department. Diagnostic strategies, including respiratory polygraphy (RP), nocturnal transcutaneous capnography (tcCO2), and blood gases (BG), were assessed for their performance in diagnosing SDB. Demographics and pulmonary function test results were compared between patients with or without SDB to identify predictors. ResultsAmong the 149 patients who underwent a full diagnostic panel (RP + tcCO2 + BG), 109 were diagnosed with SDB. Of these, 33% had isolated SAS, and central apneas were predominant. Using single diagnostic strategies would lead to inappropriate SDB management in two thirds of patients. A combination of 2 diagnostic tools resulted respectively in 21.1, 22.9 and 42.2 % of inappropriate SDB management for RP + tcCO2, RP + BG and tcCO2 + BG. ConclusionThe significant prevalence of sleep apnea syndrome in patients with slowly progressive NMD highlights the need for increased awareness among clinicians. Improved diagnostics involve a systematic approach addressing both sleep apnea and diurnal and nocturnal alveolar hypoventilation to avoid inappropriate management and limit the consequences of SDB.

Hypoventilation in patients with Prader-Willi syndrome across the pediatric age.

Few data on alveolar hypoventilation in Prader-Willi syndrome (PWS) are available and the respiratory follow-up of these patients is not standardized. The objectives of this study were to evaluate the prevalence of alveolar hypoventilation in children with PWS and identify potential risk factors. This retrospective study included children with PWS recorded by polysomnography (PSG) with transcutaneous carbon dioxide pressure (PtcCO2) or end-tidal CO2 (ETCO2) measurements, between 2007 and 2021, in a tertiary hospital center. The primary outcome was the presence of alveolar hypoventilation defined as partial pressure of carbon dioxide (pCO2) ≥ 50 mmHg during ≥2% of total sleep time (TST) or more than five consecutive minutes. Among the 57 included children (38 boys, median age 4.8 years, range 0.1-15.6, 60% treated with growth hormone [GH], 37% obese), 19 (33%) had moderate-to-severe obstructive sleep apnea syndrome (defined as obstructive apnea-hypopnea index ≥5/h) and 20 (35%) had hypoventilation. The median (range) pCO2 max was 49 mmHg (38-69). Among the children with hypoventilation, 25% were asymptomatic. Median age and GH treatment were significantly higher in children with hypoventilation compared to those without. There was no significant difference in terms of sex, BMI, obstructive or central apnea-hypopnea index between both groups. The frequency of alveolar hypoventilation in children and adolescents with PWS is of concern and may increase with age and GH treatment. A regular screening by oximetry-capnography appears to be indicated whatever the sex, BMI, and rate of obstructive or central apneas.

Obesity hypoventilation syndrome, literature review.

Obesity is a global health concern that has been increasing over the years, and it is associated with several pathophysiological changes affecting the respiratory system, including alveolar hypoventilation. Obesity hypoventilation syndrome (OHS) is one of the six subtypes of sleep-hypoventilation disorders. It is defined as the presence of obesity, chronic alveolar hypoventilation leading to daytime hypercapnia and hypoxia, and sleep-disordered breathing. The existence of a sleep disorder is one of the characteristics that patients with OHS present. Among them, 90% of patients have obstructive sleep apnea (OSA), and the remaining 10% of patients with OHS have non-obstructive sleep hypoventilation without OSA or with mild OSA. This review aims to provide a comprehensive understanding of the epidemiological and pathophysiological impact of OHS and to highlight its clinical features, prognosis, and severity, as well as the available treatment options.

Acquired Central Alveolar Hypoventilation as a Sequelae of Brainstem Tuberculoma

Acquired Central Alveolar Hypoventilation as a Sequelae of Brainstem Tuberculoma

Pediatric long-term noninvasive respiratory support in children with central nervous system disorders.

The use of long-term noninvasive respiratory support is increasing in children along with an extension of indications, in particular in children with central nervous system (CNS) disorders. The aim of this study was to describe the characteristics of children with CNS disorders treated with long-term noninvasive respiratory support in France. Data were collected from 27 French pediatric university centers through an anonymous questionnaire filled for every child treated with noninvasive ventilatory support ≥3 months on 1st June 2019. The data of 182 patients (55% boys, median age: 10.2 [5.4;14.8] years old [range: 0.3-25]) were collected: 35 (19%) patients had nontumoral spinal cord injury, 22 (12%) CNS tumors, 63 (35%) multiple disabilities, 26 (14%) central alveolar hypoventilation and 36 (20%) other CNS disorders. Seventy five percent of the patients were treated with noninvasive ventilation (NIV) and 25% with continuous positive airway pressure (CPAP). The main investigations performed before CPAP/NIV initiation were nocturnal gas exchange recordings, alone or coupled with poly(somno)graphy (in 29% and 34% of the patients, respectively). CPAP/NIV was started in an acute setting in 10% of the patients. Median adherence was 8 [6;10] hours/night, with 12% of patients using treatment <4 h/day. Nasal mask was the most common interface (70%). Airway clearance techniques were used by 31% of patients. CPAP/NIV may be a therapeutic option in children with CNS disorders. Future studies should assess treatment efficacy and patient reported outcome measures.

ROHHAD syndrome spectrum in an adult: a possible new variant.

This case report describes for the first time the evolution of a mature patient with all the diagnostic criteria for ROHHAD syndrome. It shows a rare case of central alveolar hypoventilation with hypothalamic impairment, dysautonomia and rapid weight gain. https://bit.ly/49AN3Vv.

Overview on Pediatric Obesity Hypoventilation Syndrome

The relationship between obesity and the onset of persistent daytime alveolar hypoventilation is known as obesity hypoventilation syndrome. This illness results from a complicated interaction between sleep-disordered breathing, reduced respiratory drive, and obesity-related respiratory impairment, and is associated with considerable morbidity and mortality. Extreme obesity has become far more common in the United States and other nations during the past three decades. The prevalence of OHS will inevitably rise considering the global obesity pandemic. When compared to people with sleep apnea, patients with OHS have a poorer quality of life, incur higher medical costs, and are more likely to develop pulmonary hypertension and die young. Even though this illness is associated with severe morbidity and mortality, it is commonly overlooked, and treatment is typically postponed. Clinicians need to keep a high index of suspicion since this syndrome carries a heavy burden of morbidity and mortality, which is reduced by early diagnosis and treatment. The definition and clinical presentation of OHS, a brief overview of its prevalence, a review of current understanding of pathophysiology, and discussion of recent developments in therapeutics will all be included in this review.

Evaluation of diaphragm functions with diaphragm ultrasound and pulmonary function tests in individuals with Friedreich's ataxia.

It is known that the correlation of pulmonary function tests (PFT) with muscle dysfunction is insufficient. Here, we aimed to evaluate the diaphragm functions in individuals with Friedreich's ataxia (FRDA) and to examine its relationship with respiratory parameters and disease severity. This prospective study, conducted between November and December 2022, at Erciyes University, included 14 individuals with genetically confirmed FRDA and an age- and gender-matched healthy control group of eight individuals. We examined pulmonary functions with spirometric methods and evaluated diaphragm excursion, and diaphragm thickness-expiratory (Tde) and - end of inspiration (Tdi) with ultrasonography during calm breathing. Thickening fraction (TF) calculated. Also, we examined PaCO2 at rest. The neurological status of individuals was assessed using the Scale for the Assessment and Rating of Ataxia (SARA). The mean values of FEV1(lt), FEV1(%), FVC (lt), and FVC (%) were higher in the control group (p; <0.001, 0.013, <0.001, and 0.009, respectively). Also, mean Tdi, Tde, excursion and TF were lower in the FRDA group compared to the control group (p = 0.005, 0.294,0.005, and 0.019, respectively). The mean excursion value was 1.13 ± 0.54cm in the FRDA group and 1.71 ± 0.49cm in the control group. There is a strong, negative, and statistically significant correlation between SARA total score with excursion and TF (r = -0.7432, p = 0.002; r = -0.697, p = 0.008). There is no statistically significant relationship between excursion and BMI, standing-to-supine decrease in FVC, FEV1, and PaCO2. Also, the relationship between maximal inspiratory pressure (PImax) and excursion was moderate. Diaphragm ultrasound may reveal respiratory dysfunction better than PFT. Diaphragm excursion and TF are associated with disease scores in individuals with FDRA. Further studies are needed regarding the detection of alveolar hypoventilation.