Adriana Ramirez

Respiratory muscle decline in duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) causes progressive respiratory muscle weakness. The aim of the study was to analyze the trend of a large number of respiratory parameters to gain further information on the course of the disease.

Nocturnal hypoxaemia and hypercapnia in children with neuromuscular disorders

The aim of the study was to identify daytime predictors of nocturnal gas exchange anomalies in children with neuromuscular disease (NMD) and normal daytime gas exchange. Lung function tests, respiratory muscle evaluation and nocturnal gas exchange were obtained as part of routine evaluation. We included 52 consecutive children with Duchenne muscular dystrophy (n=20), spinal muscular atrophy (n=10) and other NMD (n=22). 20 patients had nocturnal hypoxaemia, defined as minimal arterial oxygen saturation measured by pulse oximetry (Sp,O2) <90% for ≥2% of night time, and 22 had nocturnal hypercapnia, defined as maximal transcutaneous carbon dioxide tension (Ptc,CO2) >50 mmHg for ≥2% of night time. Forced vital capacity and helium functional residual capacity correlated with minimal nocturnal Sp,O2 (p=0.009 and p=0.01, respectively). Daytime pH correlated negatively with maximal nocturnal Ptc,CO2 (p=0.005) and daytime arterial carbon dioxide tension (Pa,CO2) correlated with the percentage of time with a Ptc,CO2 >50 mmHg (p=0.02). Sniff nasal inspiratory pressure correlated with minimal nocturnal Sp,O2 (p=0.02). Daytime Pa,CO2 was a weak predictor of nocturnal hypercapnia (sensitivity 80%; specificity 57%). Daytime lung function and respiratory muscle parameters correlate poorly with nocturnal hypoxaemia and hypercapnia in children with NMD and normal daytime gas exchange, which necessitates more systematic sleep studies in these children.

Continuous positive airway pressure and noninvasive ventilation adherence in children.

BACKGROUND Adherence to continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV) is crucial for the successful treatment of sleep-disordered breathing. The aim of our study was to analyze the adherence of children to long-term home CPAP/NIV treatment. METHODS We analyzed data from all consecutive patients older than the age of 2years, in whom CPAP/NIV treatment was initiated in a specialized pediatric NIV and in those who were receiving CPAP/NIV treatment at home for at least 1month. Data of the memory cards of the ventilators and nocturnal gas exchange were analyzed during a routine CPAP/NIV overnight control in the hospital. CPAP/NIV adherence during the previous month was analyzed according to patients age, ventilatory mode, type of interface, nocturnal gas exchange, and duration of treatment. RESULTS The data of 62 children (mean age, 10±5years) with obstructive sleep apnea (n=51) treated with CPAP and neuromuscular disease (n=6) or lung diseases (n=5) treated with NIV were analyzed. Mean adherence was 8:17±2:30h:min per night, and the results did not significantly differ between CPAP and NIV adherence. Seventy-two percent of the patients used their device >8h per night. The mean number of nights of CPAP/NIV use during the last month was 26±5 nights per month. Treatment adherence was not correlated to age, the type of underlying disease, the type of interface (nasal, facial mask, or nasal cannula), nocturnal gas exchange, and duration of CPAP/NIV treatment. CONCLUSION Long-term CPAP/NIV adherence at home was extremely high in this group of children followed in a pediatric NIV unit. This finding may explain the lack of effect of the interface, nocturnal gas exchange, and duration of CPAP/NIV treatment.

Lung function, diagnosis, and treatment of sleep-disordered breathing in children with achondroplasia†‡

Children with achondroplasia are at risk of sleep‐disordered breathing. The aim of the study was to evaluate lung function and sleep‐disordered breathing in children with achondroplasia. An interview, clinical examination, lung function tests with blood gases, and a polygraphic sleep study were obtained as part of routine annual evaluation in consecutive children with achondroplasia. We included 30 children (median age 3.0 years, range: 0.4–17.1) over a period of 21 months. Habitual snoring and witnessed apneas were observed in 77% and 33% of the patients, respectively. Prior to the sleep study, 10/29 (34%) patients had undergone upper airway surgery and 5/29 (17%) craniocervical decompression operation. Arterial blood gases were abnormal in two (7%) patients. Sleep findings were abnormal in 28/30 (93%) patients. Eleven (37%) patients had an apnea index ≥1 event/hr and 26 (87%) had an apnea–hypopnea index ≥5 events/hr. The ≥3% desaturation index was >5/hr in 22 (73%) patients. Sixteen (53%) patients had a minimal pulse oximetry <90% but only two (7%) patients had a maximal transcutaneous carbon dioxide pressure >50 mmHg during sleep. As a consequence, the following therapeutic interventions were performed: upper airway surgery in four patients and noninvasive positive pressure ventilation (NPPV) in five other patients, resulting in an improvement in sleep studies in all nine patients. Systematic sleep studies are recommended in children with achondroplasia because of the high prevalence of sleep‐disordered breathing. Upper airway surgery and NPPV are effective treatments of sleep‐disordered breathing.

Longitudinal course of lung function and respiratory muscle strength in spinal muscular atrophy type 2 and 3

BACKGROUND Spinal muscular atrophy (SMA) is a common genetic disorder that causes severe hypotonia and weakness, and often fatal restrictive lung disease. The aim of the study was to describe the natural history of the respiratory involvement in patients with SMA type 2 and 3 in order to assess the relevance of the clinical classification and identify the parameters associated with the earliest and most rapid decline over time. METHODS Thirty-one patients aged 3-21 years were followed over a 10-year period. Lung function, blood gases, respiratory mechanics and muscle strength with recording of oesogastric pressures were measured during routine follow-up. RESULTS At least two measurements were available in 16 patients (seven type 2 and nine type 3). Among all the volitional and non-volitional, invasive and non-invasive tests, forced vital capacity (FVC) and sniff nasal inspiratory pressure (SNIP) were shown to be the most informative parameters, showing lower values in SMA type 2, with however a similar rate of decline in patients with SMA type 2 and 3. CONCLUSION Our results confirm an earlier decline in lung and respiratory muscle function in patients classified as SMA type 2 as compared with patients classified as type 3. This decline can be assessed by two simple non-invasive tests, FVC and SNIP, with the last maneuver being feasible and reliable in the youngest children, underlying its interest for the monitoring of children with SMA.

Continuous positive airway pressure titration in infants with severe upper airway obstruction or bronchopulmonary dysplasia

AbstractaIntroductionNoninvasive continuous positive airway pressure (CPAP) is recognized as an effective treatment for severe airway obstruction in young children. The aim of the present study was to compare a clinical setting with a physiological setting of noninvasive CPAP in infants with nocturnal alveolar hypoventilation due to severe upper airway obstruction (UAO) or bronchopulmonary dysplasia (BPD).MethodsThe breathing pattern and respiratory muscle output of all consecutive infants due to start CPAP in our noninvasive ventilation unit were retrospectively analysed. CPAP set on clinical noninvasive parameters (clinical CPAP) was compared to CPAP set on the normalization or the maximal reduction of the oesophageal pressure (Poes) and transdiaphragmatic pressure (Pdi) swings (physiological CPAP). Expiratory gastric pressure (Pgas) swing was measured.ResultsThe data of 12 infants (mean age 10 ± 8 mo) with UAO (n = 7) or BPD (n = 5) were gathered. The mean clinical CPAP (8 ± 2 cmH2O) was associated with a significant decrease in Poes and Pdi swings. Indeed, Poes swing decreased from 31 ± 15 cmH2O during spontaneous breathing to 21 ± 10 cmH2O during CPAP (P < 0.05). The mean physiological CPAP level was 2 ± 2 cmH2O higher than the mean clinical CPAP level and was associated with a significantly greater improvement in all indices of respiratory effort (Poes swing 11 ± 5 cm H2O; P < 0.05 compared to clinical CPAP). Expiratory abdominal activity was present during the clinical CPAP and decreased during physiological CPAP.ConclusionsA physiological setting of noninvasive CPAP, based on the recording of Poes and Pgas, is superior to a clinical setting, based on clinical noninvasive parameters. Expiratory abdominal activity was present during spontaneous breathing and decreased in the physiological CPAP setting.

Sleep disordered breathing in patients with Prader–Willi syndrome: A multicenter study

Sleep disordered breathing (SDB) is common in patients with Prader–Willi syndrome (PWS) and systematic screening is recommended, especially before growth hormone treatment. The aim of the study was to describe the baseline SDB and therapeutic interventions in a large cohort of patients.

Evaluation of Ventilators for Mouthpiece Ventilation in Neuromuscular Disease

BACKGROUND: Daytime mouthpiece ventilation is a useful adjunct to nocturnal noninvasive ventilation (NIV) in patients with neuromuscular disease. The aims of the study were to analyze the practice of mouthpiece ventilation and to evaluate the performance of ventilators for mouthpiece ventilation. METHODS: Practice of mouthpiece ventilation was assessed by a questionnaire, and the performance of 6 home ventilators with mouthpiece ventilation was assessed in a bench test using 24 different conditions per ventilator: 3 mouthpieces, a child and an adult patient profile, and 4 ventilatory modes. RESULTS: Questionnaires were obtained from 30 subjects (mean age 33 ± 11 y) using NIV for 12 ± 7 y. Fifteen subjects used NIV for > 20 h/day, and 11 were totally ventilator-dependent. The subject-reported benefits of mouthpiece ventilation were a reduction in dyspnea (73%) and fatigue (93%) and an improvement in speech (43%) and eating (27%). The bench study showed that none of the ventilators, even those with mouthpiece ventilation software, were able to deliver mouthpiece ventilation without alarms and/or autotriggering in each condition. Alarms and/or ineffective triggering or autotriggering were observed in 135 of the 198 conditions. The occurrence of alarms was more common with a large mouthpiece without a filter compared to a small mouthpiece with a filter (P < .001), but it was not related to the patient profile, the ventilatory mode, or the type of ventilator. CONCLUSIONS: Subjects are satisfied with mouthpiece ventilation. Alarms are common with home ventilators, although less common in those with mouthpiece ventilation software. Improvements in home ventilators are needed to facilitate the expansion of mouthpiece ventilation.

Value of gas exchange recording at home in children receiving non-invasive ventilation.

Non‐invasive positive pressure ventilation (NPPV) is preferentially performed at home. The objectives of the study were to evaluate the feasibility of an overnight gas exchange recording at home and to compare recordings performed in the hospital and at home.

Medical Hypnosis as a Tool to Acclimatize Children to Noninvasive Positive Pressure Ventilation: A Pilot Study

BACKGROUND Patient cooperation is crucial for the success of noninvasive positive pressure ventilation (NPPV). This study evaluated the efficacy of medical hypnosis to reduce anticipatory anxiety and acclimatization time in children who are candidates for long-term NPPV. METHODS Medical hypnosis was performed by a trained nurse. The acclimatization time and long-term compliance with NPPV were evaluated. RESULTS Hypnosis was performed in nine children aged 2 to 15 years. Seven children had a high level of anticipatory anxiety because of a tracheotomy since birth (n=2), a history of maxillofacial surgery (n=2), severe dyspnea because of lung disease (n=2), and morbid obesity and depression (n=1), and two children with obstructive sleep apnea failed standard NPPV initiation. The hypnosis techniques were based on distraction in the youngest patient and indirect or direct hypnotic suggestions in the older children to obtain a progressive psychocorporal relaxation. All patients accepted the interface and the NPPV after the first hypnosis session. A median of three sessions was needed for overnight (>6 h) NPPV acceptance. The 6-month compliance with NPPV was excellent, with a median use of 7.5 h per night. CONCLUSION Medical hypnosis is an effective, safe, noninvasive, and inexpensive tool for reducing the anticipatory distress and acclimatization time for NPPV. This therapy is particularly useful in children with traumatic experiences, such as a tracheotomy or facial surgical procedures.