Setting of noninvasive pressure support in young patients with cystic fibrosis

ERS Statement on pediatric long term noninvasive respiratory support

Long term noninvasive respiratory support, comprising continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV), in children is expanding worldwide, with increasing complexities of children being considered for this type of ventilator support and expanding indications such as palliative care. There have been improvements in equipment and interfaces. Despite growing experience, there are still gaps in a significant number of areas: there is a lack of validated criteria for CPAP/NIV initiation, optimal follow-up and monitoring; weaning and long term benefits have not been evaluated. Therapeutic education of the caregivers and the patient is of paramount importance, as well as continuous support and assistance, in order to achieve optimal adherence. The preservation or improvement of the quality of life of the patient and caregivers should be a concern for all children treated with long term CPAP/NIV. As NIV is a highly specialised treatment, patients are usually managed by an experienced pediatric multidisciplinary team. This Statement written by experts in the field of pediatric long term CPAP/NIV aims to emphasize on the most recent scientific input and should open up to new perspectives and research areas.

Sleep in children and young adults with cystic fibrosis

Large gains have been made in the management of respiratory diseases associated with cystic fibrosis (CF). Initial studies evaluating sleep issues in CF focused on respiratory problems of nocturnal hypoxia, alveolar hypoventilation and risk of airway obstruction from nasal polyps with treatment evaluations including long term oxygen therapy or noninvasive ventilation in case of nocturnal hypercapnia. More recent studies include patients whose lung function is better preserved, and have permitted more focus on sleep patterns and sleep quality. This literature identified that reduced sleep duration and poor sleep quality are common and may be explained by chronic pain and cough, frequent stools, gastro-oesophageal reflux, nasal obstruction or sinusitis, and drugs such as corticosteroids or beta-agonists. In the teenage years, poor sleep hygiene, sleep debt and poor sleep quality are associated with depression, poor academic performance, less physical activity, and a decrease in quality of life. Restless leg syndrome also seems to be common in adult patients with CF. These sleep problems seem more important in patients with a low lung function but may also be observed in patients with preserved lung function. The consequences of poor sleep may potentially exaggerate the multi-organ morbidity of CF, such as pain, inflammation, susceptibility to infection, and glucose intolerance, but these aspects are largely under-evaluated. Sleep should be evaluated on a routine basis in CF and prospective studies assessing the benefits of interventions aiming at improving sleep duration and sleep quality urgently needed.

Non-invasive ventilation is associated with long-term improvements in lung function and gas exchange in cystic fibrosis adults with hypercapnic respiratory failure

BACKGROUND

Non-invasive ventilation (NIV) is an established treatment option for cystic fibrosis (CF) patients with type 2 respiratory failure but the benefits of this therapy remain unclear. This study examined the long-term outcomes and response to NIV in a large adult CF cohort.

METHODS

All patients attending a UK adult CF Centre receiving NIV as treatment for hypercapnic respiratory failure over a nine-year period were studied prospectively. Detailed clinical data was recorded and longitudinal data measurements were examined for the three years pre and post NIV initiation to assess effect of this intervention.

RESULTS

94 patients, mean age 29.9 (SD 9.7) years, percent predicted FEV₁ 21.5 (7.3), received NIV. All patients commenced NIV in a hospital setting. 21 remain alive, 24 received double lung transplant, 49 died without lung transplantation. NIV use was associated with a stabilisation and improvement in both FEV₁ and FVC from NIV set up to three years post follow-up, in addition to an increase in body mass index and attenuation of PCO₂ (all p<0.001). No single parameter was found to predict long-term NIV response but baseline PCO₂ (p=0.005), CRP (p=0.004) and age (p=0.009) were identified as independent predictors of mortality.

CONCLUSIONS

NIV use in CF adults is associated with improvements in lung function and attenuation of hypercapnia which is maintained for up to three years post NIV initiation. Outcomes for CF patients with severe pulmonary disease commenced on NIV have significantly improved with fifty percent of patients expected to survive for approximately five years.

Evolution of Pediatric Home Mechanical Ventilation Program in Serbia-What Has Changed in the Last Decade

Home mechanical ventilation (HMV) is a method of treatment in children with sleep-disordered breathing (SDB) and alveolar hypoventilation regardless of primary disease. The goal of the study was to describe the changes in the HMV program in Serbia during the last two decades. Cross-sectional retrospective study included data from the national HMV database from 2001 until 2019. HMV was initiated in clinically stable patients after the failure to wean from mechanical ventilation succeeded acute respiratory deterioration or electively after the confirmation of SDB and alveolar hypoventilation by sleep study or continuous transcutaneous capnometry and oximetry. The study included 105 patients (50 ventilated noninvasively and 55 ventilated invasively via tracheostomy). The median age at the time of HMV initiation was 6.2 years (range: 0.3-18 years). Invasive ventilation had been initiated significantly earlier than noninvasive ventilation (NIV) (p < 0.01), without difference in duration of ventilatory support (p = 0.95). Patients on NIV were significantly older (p < 0.01) than those ventilated invasively (13 and 1.5 years, respectively). Average waiting time on equipment had been shortened significantly-from 6.3 months until 2010 to 1 month at the end of the study (p < 0.01). Only 6.6% of patients had obstructive sleep apnea syndrome (OSAS) requiring HMV. During the study period, 24% patients died, mostly due to uncontrolled infection or progression of underlying disease. Availability and shortened waiting time for the equipment accompanied by advanced overall health care led to substantial improvements in the national HMV program. However, future improvements should be directed to systematic evaluation of SDB in patients with OSAS, early diagnosis of nocturnal hypoventilation, and subsequent timely initiation of chronic ventilation.

High-flow nasal oxygen versus noninvasive ventilation in adult patients with cystic fibrosis: a randomized crossover physiological study

Background

Noninvasive ventilation (NIV) is the first-line treatment of adult patients with exacerbations of cystic fibrosis (CF). High-flow nasal oxygen therapy (HFNT) might benefit patients with hypoxemia and can reduce physiological dead space. We hypothesized that HFNT and NIV would similarly reduce work of breathing and improving breathing pattern in CF patients. Our objective was to compare the effects of HFNT versus NIV in terms of work of breathing, assessed noninvasively by the thickening fraction of the diaphragm (TFdi, measured with ultrasound), breathing pattern, transcutaneous CO₂ (PtcCO₂), hemodynamics, dyspnea and comfort.

Methods

Adult CF patients who had been stabilized after requiring ventilatory support for a few days were enrolled and ventilated with HFNT and NIV for 30 min in crossover random order.

Results

Fifteen patients were enrolled. Compared to baseline, HFNT, but not NIV, reduced respiratory rate (by 3 breaths/min, p = 0.01) and minute ventilation (by 2 L/min, p = 0.01). Patients also took slightly larger tidal volumes with HFNT compared to NIV (p = 0.02). TFdi per breath was similar under the two techniques and did not change from baseline. MAP increased from baseline with NIV and compared to HFNT (p ≤ 0.01). Comfort was poorer with the application of both HFNT and NIV than baseline. No differences were found for heart rate, SpO₂, PtcCO₂ or dyspnea.

Conclusions

In adult CF patients stabilized after indication for ventilatory support, HFNT and NIV have similar effects on diaphragmatic work per breath, but high-flow therapy confers additional physiological benefits by decreasing respiratory rate and minute ventilation.

Clinical trial registration

Ethics Committee of St. Michael’s Hospital (REB #14-338) and clinicaltrial.gov (NCT02262871).

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0432-4) contains supplementary material, which is available to authorized users.

Esogastric pressure measurement to assist noninvasive ventilation indication and settings in infants with hypercapnic respiratory failure: A pilot study

OBJECTIVE

Noninvasive ventilation (NIV) in usually set on clinical parameters. The aim of the study was to assess the value of esophageal (P_ES ) and gastric pressure (P_GAS ) measurements for the indication and optimal settings of NIV in infants with hypercapnic respiratory failure in whom the efficacy of NIV was uncertain on clinical noninvasive parameters.

DESIGN

A retrospective study.

PATIENT-SUBJECT SELECTION

P_ES and P_GAS measurements were performed in seven infants <2 years old admitted in the Pediatric Intensive Care Unit for an acute or acute-on-chronic hypercapnic respiratory failure.

METHODOLOGY

P_ES swing and esophageal pressure time product (PTP_ES ) during spontaneous breathing, NIV set on clinical parameters (NIVclin) and on P_ES (NIVphys) were compared. According to the P_ES measurements, NIV was continued if NIV was associated with an at least 20% reduction of the P_ES swing and PTP_ES and not initiated or withdrawn in the other case.

RESULTS

In all seven patients, the P_ES and P_GAS measurements were informative and led to the decision to initiate NIV in one patient or continue NIV with different settings in three patients. In the three other patients, NIV was not initiated in one patient and withdrawn in the two last patients because of a lack of improvement in P_ES swing and PTP_ES .

CONCLUSIONS

P_ES and P_GAS measurements may be useful for the indication and optimal setting of NIV in a selected group of infants with hypercapnic respiratory failure.

Recent Advances in Pediatric Ventilatory Assistance

In this review on respiratory assistance, we aim to discuss the following recent advances: the optimization and customization of mechanical ventilation, the use of high-frequency oscillatory ventilation, and the role of noninvasive ventilation. The prevention of ventilator-induced lung injury and diaphragmatic dysfunction is now a key aspect in the management of mechanical ventilation, since these complications may lead to higher mortality and prolonged length of stay in intensive care units. Different physiological measurements, such as esophageal pressure, electrical activity of the diaphragm, and volumetric capnography, may be useful objective tools to help guide ventilator assistance. Companies that design medical devices including ventilators and respiratory monitoring platforms play a key role in knowledge application. The creation of a ventilation consortium that includes companies, clinicians, researchers, and stakeholders could be a solution to promote much-needed device development and knowledge implementation.

[Non-invasive ventilation in children: Do we need more evidence?]

Respiratory failure is the leading cause of hospital admissions in the pediatric intensive care unit (PICU) and is associated with significant morbidity and mortality. Mechanical ventilation, preferentially delivered by a non-invasive route (NIV), is currently the first-line treatment for respiratory failure since it is associated with a reduction in the intubation rate. This ventilatory support is increasingly used in the PICU, but its wider use contrasts with the paucity of studies in this field. This review aims to describe the main indications of NIV in acute settings: (i) bronchiolitis; (ii) postextubation respiratory failure; (iii) acute respiratory distress syndrome; (iv) pneumonia; (v) status asthmaticus; (vi) acute chest syndrome; (vii) left heart failure; (viii) exacerbation of chronic respiratory failure; (ix) upper airway obstruction and (x) end-of-life care. Most of these data are based on descriptive studies and expert opinions, and few are from randomized trials. While the benefit of NIV is significant in some indications, such as bronchiolitis, it is more questionable in others. Monitoring these patients for the occurrence of NIV failure markers is crucial.

Improvement of the trigger of a ventilator for non-invasive ventilation in children: bench and clinical study

BACKGROUND AND AIMS

Even though numerous ventilators are licensed for a use in children, very few have been specifically developed for this age range. Therefore, home ventilators may not be able to adequately synchronize with the child's respiratory effort, and the inspiratory triggers (ITs) of assist modes are not always appropriate for children. The aim of the study was to test the improvement of the IT of a ventilator on a pediatric bench and in pediatric patients.

METHODS

A classical IT (ITc) and an improved IT [non-invasive ventilation (NIV) + IT] were tested on a bench with six pediatric profiles and in six young patients (mean age 14.1 ± 2.7 years old) requiring long-term NIV.

RESULTS

On the bench, trigger time delays (ΔT) and trigger pressures (ΔP) were reduced with the NIV + IT as compared with the ITc (ΔT: 0.481 ± 0.332 vs 0.079 ± 0.022 s for ITc and NIV + IT, respectively, P = 0.027; ΔP: -1.40 ± 0.70 vs -0.42 ± 0.28 cmH2 O for ITc and NIV + IT, respectively, P = 0.046). The clinical study confirmed the decrease in ΔT (0.267 ± 0.061 vs 0.178 ± 0.074 s for ITc and NIV + IT, respectively, P = 0.024) and ΔP (-0.68 ± 0.26 vs -0.39 ± 0.11 cmH2 O for ITc and NIV + IT, respectively, P = 0.030).

CONCLUSIONS

The sensitivity of the IT of a ventilator can be improved for pediatric use. The improvements observed on the bench study were confirmed in pediatric patients.

Long-term non-invasive ventilation therapies in children: a scoping review protocol

INTRODUCTION

Non-invasive ventilation (NIV) in children has become an increasingly common modality of breathing support where pressure support is delivered through a mask interface or less commonly through other non-invasive interfaces. At this time, NIV is considered a first-line option for ventilatory support of chronic respiratory insufficiency associated with a range of respiratory and sleep disorders. Previous reviews on the effectiveness, complications and adherence to NIV treatment have lacked systematic methods. The purpose of this scoping review is to provide an overview of the evidence for the use of long-term NIV in children.

METHODS AND ANALYSIS

We will use previously established scoping methodology. Ten electronic databases will be searched to identify studies in children using NIV for longer than 3 months outside an intensive care setting. Grey literature search will include conference proceedings, thesis and dissertations, unpublished trials, reports from regulatory agencies and manufacturers. Two reviewers will independently screen titles and abstracts for inclusion, followed by full-text screening of potentially relevant articles to determine final inclusion. Data synthesis will be performed at three levels: (1) an analysis of the number, publication type, publication year, and country of publication of the studies; (2) a summary of the study designs, outcomes measures used; (3) a thematic analysis of included studies by subgroups.

ETHICS AND DISSEMINATION

This study will provide a wide and rigorous overview of the evidence on the use of long-term NIV in children and provide critical information for healthcare professionals and policymakers to better care for this group of children. We will disseminate our findings through conference proceedings and publications, and evaluate the results for further systematic reviews and meta-analyses.

Determinants of respiratory pump function in patients with cystic fibrosis

Respiratory failure constitutes the major cause of morbidity and mortality in patients with Cystic Fibrosis (CF). Respiratory failure could either be due to lung parenchyma damage or to insufficiency of the respiratory pump which consists of the respiratory muscles, the rib cage and the neuromuscular transmission pathways. Airway obstruction, hyperinflation and malnutrition have been historically recognised as the major determinants of respiratory pump dysfunction in CF. Recent research has identified chronic infection, genetic predisposition, dietary and pharmaceutical interventions as possible additional determinants of this impairment. Furthermore, new methodological approaches in assessing respiratory pump function have led to a better understanding of the pathogenesis of respiratory pump failure in CF. Finally, respiratory muscle function could be partially preserved in CF patients with structured interventions such as aerobic exercise, inspiratory muscle training and non-invasive ventilation and CF patients could consequently be relatively protected from respiratory fatigue and respiratory failure.

Home mechanical ventilation in children is feasible in developing countries

BACKGROUND

The results of many national surveys on pediatric home mechanical ventilation (HMV) in developed countries have been presented elsewhere, but data from developing countries with low national incomes are scarce.

METHODS

Twenty-nine pediatric patients, treated in the Mother and Child Institute of Serbia, who had been receiving long-term ventilatory support at home, were surveyed. The major criterion for initiating HMV was hypercapnia, diagnosed by blood gas analysis, performed in the morning, after awakening. Other criteria were either symptoms of hypoventilation during the night associated with an apnea index of >5, or apnoea-hypopnoea index of >15, or nocturnal hypoxemia, defined as an oxygen saturation rate of <90% for >5% of total sleep time.

RESULTS

The mean age at initiation of HMV was 9.3 years (range 0.5-17.8 years). Patients waited for HMV initiation either in hospital or at home; the mean period was 6.3 months (range 1-18 months). The subjects received HMV for a mean of 25.06 months (range 3-119 months). There was a significant difference in the duration of HMV for different underlying diseases (P= 0.046), and mechanical malfunction was strongly dependent on the duration of HMV (P= 0.011). Eleven patients underwent invasive HMV via a tracheostomy, and 18 others received non-invasive ventilation, via nasal and full-face masks.

CONCLUSION

HMV is feasible in developing countries. Valuable reimbursement policies as well as an organized and functional network are essential for its implementation, as a standard of care in leading national pediatric hospitals.

Longitudinal lung function and structural changes in children with primary ciliary dyskinesia

BACKGROUND AND OBJECTIVES

Functional and structural lung evaluations are part of the follow-up of patients with primary ciliary dyskinesia (PCD). We aimed to evaluate transversal and longitudinal relationships between lung function test (LFT) and chest computed tomography (CT) in children with PCD, in stable clinical condition.

MATERIALS AND METHODS

Data from children followed in the French National Center were retrospectively collected. Inclusion criteria were (i) definitive diagnosis of PCD, (ii) age less than 15 years at the beginning of follow-up, (iii) at least 8 years of follow-up, (iv) at least two couples of concurrent CT and LFT available in a phase of clinical stability of the lung disease without modification of the treatment regimen in the last 4 weeks. Twenty children (median age at entry 4.6 years, median follow-up 15.4 years) were included. Concurrent LFT (blood gas and spirometry) and CT (score) results were recorded.

RESULTS

LFT indices (PaO(2) (n = 210), FVC, FEV(1) , FEF(2575%) (n = 195)) significantly decreased with age, and the mean annual decrease (z-score (% predicted)) was -0.17 (-0.49%), -0.09 (-0.50%), -0.10 (-0.89%), and -0.07 (-1.73%), respectively. First CT (median age 8.7 years) revealed bronchiectasis (70%), mucous plugging (70%), peribronchial thickening (90%), parenchymal abnormalities (65%), and hyperinflation (50%). CT scores (n = 74) significantly increased with age, and was negatively correlated to PaO(2), FVC, FEV(1), and FEF(2575%) longitudinal changes.

CONCLUSION

In stable clinical condition, functional, and structural progressive impairments significantly correlated in children with PCD. Further prospective studies, including large populations of patients with various levels of disease severity, are needed to confirm whether lung function follow-up can be used to adjust CT frequency and help at minimizing the radiation burden in children with a good life expectancy.

Safety, efficacy, and tolerability of early initiation of noninvasive positive pressure ventilation in pediatric patients admitted with status asthmaticus: a pilot study

OBJECTIVES

Although noninvasive positive pressure ventilation is increasingly used for respiratory distress, there is not much data supporting its use in children with status asthmaticus. The objective of this study was to determine safety, tolerability, and efficacy of early initiation of noninvasive positive pressure ventilation in addition to standard of care in the management of children admitted with status asthmaticus.

STUDY DESIGN

A prospective, randomized, controlled, clinical trial.

PATIENTS

Twenty patients (1-18 yrs old) admitted to the pediatric intensive care unit with status asthmaticus.

METHODS AND MAIN RESULTS

Children were randomized to receive either noninvasive positive pressure ventilation plus standard of care (noninvasive positive pressure ventilation group) or standard of care alone (standard group). Improvement in clinical asthma score was significantly greater in noninvasive positive pressure ventilation group compared to standard group at 2 hrs, 4-8 hrs, 12-16 hrs, and 24 hrs after initiation of interventions (p < .01). A significant decrease in respiratory rate at ≥ 24 hrs oxygen requirement after 2 hrs was noted in noninvasive positive pressure ventilation group as compared to standard group (p = .01 and p = .03, respectively). Although statistically not significant, fewer children in the noninvasive positive pressure ventilation group required adjunct therapy compared to standard group (11% vs. 50%; p = .07). There were no major adverse events related to noninvasive positive pressure ventilation. Nine out of ten patients tolerated noninvasive positive pressure ventilation through the duration of the study; noninvasive positive pressure ventilation had to be discontinued in one patient because of persistent cough.

CONCLUSIONS

Early initiation of noninvasive positive pressure ventilation, along with short acting β-agonists and systemic steroids, can be safe, well-tolerated, and effective in the management of children with status asthmaticus.

Noninvasive ventilation in pediatric acute respiratory failure by means of a conventional volumetric ventilator

BACKGROUND

Acute respiratory failure (ARF) is one of the main causes for admission to pediatric intensive care unit (PICU). This study aimed to evaluate the feasibility and outcome of noninvasive ventilation (NIV) by a volumetric ventilator with a specific mode in pediatric acute respiratory failure.

METHODS

A three-year prospective non-controlled study was undertaken in children with ARF who had received NIV delivered by Evita 2 Dura with NIV mode through a nonvented oronasal mask.

RESULTS

Thirty-two episodes of ARF were observed in 26 patients. Pneumonia was observed in most of the children (46.8%). Pediatric logistic organ dysfunction (PELOD) score was 12.4% ± 24% (range 0-84%). Peak inspiratory pressure was 18.5 ± 2.7 cmH₂O, positive end-expiratory pressure 5.7 ± 1.1 cmH₂O, pressure support 10.5 ± 2.7 cmH₂O, and mean pressure 9.2 ± 2 cmH₂O. The clinical score was improved progressively within the first 6 hours. Before the initiation of NIV, respiratory rate was 41.7 ± 16.3, heart rate 131.6 ± 25.8, systolic arterial pressure 108 ± 19.5, diastolic arterial pressure 58.2 ± 13.9, pH 7.33 ± 0.12, pCO₂ 55.1 ± 20.2, SatO₂ 87.8 ± 9.9 and FiO₂ 0.55 ± 0.25. There was a significant improvement in the respiratory rate, heart rate, pH, pCO₂ and SatO₂ at 2-4 hours. This improvement was kept throughout the first 24 hours. The level of FiO₂ was significantly lower at 24 hours. Radiological improvement was observed after 24 hours in 17 out of 26 patients. The duration of NIV was 85.4 ± 62.8 hours. Complications were defined as minor. Only 4 patients required intubation. All patients survived.

CONCLUSIONS

NIV can be successfully applied to infants and children with ARF using this volumetric ventilator with specific NIV mode. It should be considered particularly in children whose underlying condition warrants avoidance of intubation.

Noninvasive positive-pressure ventilation avoids recannulation and facilitates early weaning from tracheotomy in children

OBJECTIVE

To show that noninvasive positive-pressure ventilation by means of a nasal mask may avoid recannulation after decannulation and facilitate early decannulation.

DESIGN

Retrospective cohort study.

SETTING

Ear-nose-and-throat and pulmonary department of a pediatric university hospital.

PATIENTS

The data from 15 patients (age = 2-12 yrs) who needed a tracheotomy for upper airway obstruction (n = 13), congenital diaphragmatic hypoplasia (n = 1), or lung disease (n = 1) were analyzed. Four patients received also nocturnal invasive ventilatory support for associated lung disease (n = 3) or congenital diaphragmatic hypoplasia (n = 1). Decannulation was proposed in all patients because endoscopic evaluation showed sufficient upper airway patency and normal nocturnal gas exchange with a small size closed tracheal tube, but obstructive airway symptoms occurred either immediately or with delay after decannulation without noninvasive positive-pressure ventilation.

INTERVENTIONS

In nine patients, noninvasive positive-pressure ventilation was started after recurrence of obstructive symptoms after a delay of 1 to 48 mos after a successful immediate decannulation. Noninvasive positive-pressure ventilation was anticipated in six patients who failed repeated decannulation trials because of poor clinical tolerance of tracheal tube removal or tube closure during sleep.

MEASUREMENTS AND MAIN RESULTS

After noninvasive positive-pressure ventilation acclimatization, decannulation was performed with success in all patients. Noninvasive positive-pressure ventilation was associated with an improvement in nocturnal gas exchange and marked clinical improvement in their obstructive sleep apnea symptoms. None of the 15 patients needed tracheal recannulation. Noninvasive positive-pressure ventilation could be withdrawn in six patients after 2 yrs to 8.5 yrs. The other nine patients still receive noninvasive positive-pressure ventilation after 1 yr to 6 yrs.

CONCLUSIONS

In selected patients with upper airway obstruction or lung disease, noninvasive positive-pressure ventilation may represent a valuable tool to treat the recurrence of obstructive symptoms after decannulation and may facilitate early weaning from tracheotomy in children who failed repeated decannulation trials.

Long-term gas exchange characteristics as markers of deterioration in patients with cystic fibrosis

Background and Aim

In patients with cystic fibrosis (CF) the architecture of the developing lungs and the ventilation of lung units are progressively affected, influencing intrapulmonary gas mixing and gas exchange. We examined the long-term course of blood gas measurements in relation to characteristics of lung function and the influence of different CFTR genotype upon this process.

Methods

Serial annual measurements of PaO₂ and PaCO₂ assessed in relation to lung function, providing functional residual capacity (FRC_pleth), lung clearance index (LCI), trapped gas (V_TG), airway resistance (sR_eff), and forced expiratory indices (FEV₁, FEF₅₀), were collected in 178 children (88 males; 90 females) with CF, over an age range of 5 to 18 years. Linear mixed model analysis and binary logistic regression analysis were used to define predominant lung function parameters influencing oxygenation and carbon dioxide elimination.

Results

PaO₂ decreased linearly from age 5 to 18 years, and was mainly associated with FRC_pleth, (p < 0.0001), FEV₁ (p < 0.001), FEF₅₀ (p < 0.002), and LCI (p < 0.002), indicating that oxygenation was associated with the degree of pulmonary hyperinflation, ventilation inhomogeneities and impeded airway function. PaCO₂ showed a transitory phase of low PaCO₂ values, mainly during the age range of 5 to 12 years. Both PaO₂ and PaCO₂ presented with different progression slopes within specific CFTR genotypes.

Conclusion

In the long-term evaluation of gas exchange characteristics, an association with different lung function patterns was found and was closely related to specific genotypes. Early examination of blood gases may reveal hypocarbia, presumably reflecting compensatory mechanisms to improve oxygenation.

Non-invasive ventilation in children with upper airway obstruction

OBJECTIVE

The aim of this paper is to highlight our experience with the use of non-invasive positive pressure ventilation (NIPPV) in children, neonates and pre-term infants with upper airway obstruction.

METHODS

This was a retrospective review of our recent experience in using NIPPV for the management of upper airway obstruction in paediatric patients.

RESULTS

NIPPV was successful in preventing tracheostomy in patients with significant laryngo-tracheomalacia as well as being used to optimise the timing of surgery in subglottic stenosis. Furthermore, it proved beneficial in stabilising the airway after aryepiglottoplasty and also had a role in the management of obstructive sleep apnoea.

CONCLUSION

The use of NIPPV in children with upper airway obstruction can be a safe and effective alternative to invasive mechanical ventilation. NIPPV can potentially be beneficial in avoiding prolonged invasive ventilation, avoiding tracheostomy, stabilizing the airway after extubation or decannulation, and management of obstructive sleep apnoea.

Noninvasive ventilation in immunocompromised pediatric patients: eight years of experience in a pediatric oncology intensive care unit

OBJECTIVE

The experience of noninvasive positive pressure ventilation (NPPV) in the pediatric setting is limited. The aim of the present study is to retrospectively evaluate the effectiveness of NPPV in pediatric immunocompromised patient admitted in our PICU (Pediatric Intensive Care Unit) for acute respiratory failure.

DESIGN/SETTING

Retrospective cohort study of children admitted to the PICU of Hospital do Cancer between June 1997 and May 2005 requiring ventilatory support.

RESULTS

A total of 239 admissions were included. The first mechanical ventilation (MV) technique used was NPPV in 120 (50.2%) patients [noninvasive ventilation (NIV) group] and conventional MV in 119 (49.8%) [invasive ventilation (IV) group]; 25.8% of the patients from the NIV group subsequently required intubation. Patients in the IV group were more likely to be in a severe clinical status. Characteristics associated with severe clinical status were median value for therapeutic intervention scoring system score (37.5 points IV vs. 29 points NIV, P<0.0001), presence of >2 organs failure (63.6% IV vs. 36.4% NIV, P<0.0001), cardiac failure (62.5% IV vs. 37.5% NIV, P<0.0001), and septic shock (63.9% IV vs. 36.1% NIV, P<0.0001). Documented severe pulmonary disease was significantly higher (67.6%) in IV group, P=0.02. Baseline values of arterial pCO2, hypoxemia, arterial pH, and respiratory rate did not differ between the groups. Multivariate analysis showed that independent predictive factors for intubation were solid tumors (P=0.012), cardiovascular dysfunction (P<0.0001), and therapeutic intervention scoring system score >or=40 points (P=0.018).

CONCLUSIONS

Our results encourage the use of NPPV as a first-line treatment in children with malignancies who develops acute respiratory failure, except in those with severe hemodynamic status.

Recurrence plots for dynamical analysis of non-invasive mechanical ventilation

Quantifiers were introduced to convert recurrence plots into a statistical analysis of dynamical properties. It is shown that the Shannon entropy, if properly computed, increases as the chaotic regime is developed as expected. Recurrence plots and a new estimator for the Shannon entropy are then used to identify asynchronisms in non-invasive mechanical ventilation. It is thus shown that the phase coherence-easily identified using a Shannon entropy-is relevant in the quality of the mechanical ventilation. In particular, some patients with chronic respiratory diseases or healthy subjects can have a high rate of asynchronisms but a regular breathing rhythm.

Clinical review: long-term noninvasive ventilation

Noninvasive positive ventilation has undergone a remarkable evolution over the past decades and is assuming an important role in the management of both acute and chronic respiratory failure. Long-term ventilatory support should be considered a standard of care to treat selected patients following an intensive care unit (ICU) stay. In this setting, appropriate use of noninvasive ventilation can be expected to improve patient outcomes, reduce ICU admission, enhance patient comfort, and increase the efficiency of health care resource utilization. Current literature indicates that noninvasive ventilation improves and stabilizes the clinical course of many patients with chronic ventilatory failure. Noninvasive ventilation also permits long-term mechanical ventilation to be an acceptable option for patients who otherwise would not have been treated if tracheostomy were the only alternative. Nevertheless, these results appear to be better in patients with neuromuscular/-parietal disorders than in chronic obstructive pulmonary disease. This clinical review will address the use of noninvasive ventilation (not including continuous positive airway pressure) mainly in diseases responsible for chronic hypoventilation (that is, restrictive disorders, including neuromuscular disease and lung disease) and incidentally in others such as obstructive sleep apnea or problems of central drive.

Non-invasive positive ventilation in the treatment of sleep-related breathing disorders

This chapter addresses the use of long-term non-invasive positive pressure ventilation (NIPPV) (to the exclusion of continuous positive airway pressure) in the different clinical settings in which it is currently proposed: principally in diseases responsible for hypoventilation characterized by elevated PaCO(2). Nasal masks are predominantly used, followed by nasal pillow and facial masks. Mouthpieces are essentially indicated in case daytime ventilation is needed. Many clinicians currently prefer pressure-preset ventilator in assist mode as the first choice for the majority of the patients with the view of offering better synchronization. Nevertheless, assist-control mode with volume-preset ventilator is also efficient. The settings of the ventilator must insure adequate ventilation assessed by continuous nocturnal records of at least oxygen saturation of haemoglobin-measured by pulse oximetry. The main categories of relevant diseases include different types of neuromuscular disorders, chest-wall deformities and even lung diseases. Depending on the underlying diseases and on individual cases, two schematic situations may be individualized. Either intermittent positive pressure ventilation (IPPV) is continuously mandatory to avoid death in the case of complete or quasi-complete paralysis or is used every day for several hours, typically during sleep, producing enough improvement to allow free time during the daylight in spontaneous breathing while hypoventilation and related symptoms are improved. In case of complete or quasi-complete need of mechanical assistance, a tracheostomy may become an alternative to non-invasive access. In neuromuscular diseases, in kyphosis and in sequela of tuberculosis patients, NIPPV always significantly increases survival. Conversely, no data support a positive effect on survival in chronic obstructive pulmonary disease.

Noninvasive positive pressure ventilation: five years of experience in a pediatric intensive care unit

OBJECTIVES

To evaluate the feasibility and outcome of noninvasive positive pressure ventilation (NPPV) in daily clinical practice.

DESIGN

Observational retrospective cohort study.

SETTING

Pediatric intensive care unit in a university hospital.

PATIENTS

: Patients treated by NPPV, regardless of the indication, during five consecutive years (2000-2004).

MEASUREMENTS AND RESULTS

A total of 114 patients were included, and 83 of the 114 patients (77%) were successfully treated by NPPV without intubation (NPPV success group). The success rate of NPPV was significantly lower (22%) in the patients with acute respiratory distress syndrome (p < .05) than in the other patients. The Pediatric Risk of Mortality II (p = .003) and Pediatric Logistic Organ Dysfunction scores (p = .002) at admission were significantly higher in patients who were unsuccessfully treated with NPPV (NPPV failure group). Baseline values of Pco2, pulse oximetry, and respiratory rate did not differ between the two groups. A significant decrease in Pco2 and respiratory rate within the first 2 hrs of NPPV was observed in the NPPV success group. Multivariate analysis showed that a diagnosis of acute respiratory distress syndrome (odds ratio, 76.8; 95% confidence interval, 4.4-1342; p = .003) and a high Pediatric Logistic Organ Dysfunction score (odds ratio, 1.09; 95% confidence interval, 1.01-1.17; p = .01) were independent predictive factors for NPPV failure. A total of 11 patients (9.6%), all belonging to the NPPV failure group, died during the study.

CONCLUSIONS

This study demonstrates the feasibility and efficacy of NPPV in the daily practice of a pediatric intensive care unit. This ventilatory support could be proposed as a first-line treatment in children with acute respiratory distress, except in those with a diagnosis of acute respiratory distress syndrome.

Respiratory muscle testing: a valuable tool for children with neuromuscular disorders

RATIONALE

Data on respiratory muscle performance in children with neuromuscular disorders are limited.

OBJECTIVES

The aim of this study was to assess respiratory muscle strength by volitional and nonvolitional tests and to compare these tests with forced vital capacity.

METHODS

Inspiratory muscle strength was assessed by measuring transdiaphragmatic and esophageal pressures generated during volitional and nonvolitional maneuvers, whereas expiratory muscle strength was assessed by measuring the gastric pressure generated during a cough maneuver. Lung volumes were assessed by measuring forced vital capacity.

MEASUREMENTS AND MAIN RESULTS

Forty-one patients with Duchenne muscular dystrophy (n = 20), spinal amyotrophy (n = 8), and congenital myopathy (n = 13) were included, aged 2 to 18 yr. All the patients were able to perform the sniff and the cough maneuver. Sniff transdiaphragmatic pressure decreased with age in Duchenne patients, whereas it increased with age in patients with spinal amyotrophy and congenital myopathy. Magnetic stimulation of the phrenic nerves was obtained in all patients. Twenty-five (61%) patients were able to perform forced vital capacity. In the three groups of patients, a positive correlation was observed between volitional, assessed by the sniff maneuver, and nonvolitional respiratory muscle tests, assessed by the magnetic stimulation of the phrenic nerves. Also, forced vital capacity correlated with sniff transdiaphragmatic pressure and cough gastric pressure.

CONCLUSIONS

Volitional respiratory muscle tests correlated with nonvolitional tests and with forced vital capacity. Simple volitional respiratory muscle tests constitute a valuable tool for the assessment of respiratory muscle strength in young patients with neuromuscular disorders.

L’assistance ventilatoire non invasive à domicile chez l’enfant

INTRODUCTION

Non-invasive positive pressure ventilation (NPPV) represents a particularly interesting technique of ventilatory support in paediatrics. Indeed, a significant number of pathologies that may be responsible for chronic respiratory insufficiency in childhood, such as neuromuscular diseases, obstruction of the upper airways, disorders of chest wall and/or the lungs, and disorders of ventilatory control may all lead to alveolar hypoventilation that can be improved by ventilatory support.

BACKGROUND

Few physiological studies have been performed on NPPV in children. The most appropriate modes and settings for each pathology have not been clearly defined, and the criteria for commencing NPPV are based essentially on consensus guidelines for the management of neuromuscular disorders.

VIEWPOINT

All the health care professionals managing these children should combine their efforts to evaluate more precisely the medium and long-term physiological effects of NPPV on the respiratory muscles, the development of the respiratory system, inspiratory activity, the indications for starting treatment and, above all, the benefits in terms of psycho-neurological development and quality of life.

CONCLUSIONS

A better evaluation of the medium and long-term physiological and psychological benefits together with technical improvements in ventilators and associated equipment should allow a rapid expansion in the use of domiciliary NPPV in children.

Noninvasive positive pressure ventilation in infants with upper airway obstruction: comparison of continuous and bilevel positive pressure

OBJECTIVE

This study evaluated the efficacy of noninvasive continuous positive pressure (CPAP) ventilation in infants with severe upper airway obstruction and compared CPAP to bilevel positive airway pressure (BIPAP) ventilation.

DESIGN AND SETTING

Prospective, randomized, controlled study in the pulmonary pediatric department of a university hospital.

PATIENTS

Ten infants (median age 9.5 months, range 3-18) with laryngomalacia (n=5), tracheomalacia (n=3), tracheal hypoplasia (n=1), and Pierre Robin syndrome (n=1).

INTERVENTIONS

Breathing pattern and respiratory effort were measured by esophageal and transdiaphragmatic pressure monitoring during spontaneous breathing, with or without CPAP and BIPAP ventilation.

MEASUREMENTS AND RESULTS

Median respiratory rate decreased from 45 breaths/min (range 24-84) during spontaneous breathing to 29 (range 18-60) during CPAP ventilation. All indices of respiratory effort decreased significantly during CPAP ventilation compared to unassisted spontaneous breathing (median, range): esophageal pressure swing from 28 to 10 cmH(2)O (13-76 to 7-28), esophageal pressure time product from 695 to 143 cmH(2)O/s per minute (264-1417 to 98-469), diaphragmatic pressure time product from 845 to 195 cmH(2)O/s per minute (264-1417 to 159-1183) During BIPAP ventilation a similar decrease in respiratory effort was observed but with patient-ventilator asynchrony in all patients.

CONCLUSIONS

This short-term study shows that noninvasive CPAP and BIPAP ventilation are associated with a significant and comparable decrease in respiratory effort in infants with upper airway obstruction. However, BIPAP ventilation was associated with patient-ventilator asynchrony.