Treatment of acute respiratory failure by helmet-delivered non-invasive pressure support ventilation in children with acute leukemia: a pilot study

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

Home mechanical ventilation in children with chronic respiratory failure: a narrative review

Advances in perinatal and pediatric intensive care and recent advances in mechanical ventilation during the last two decades have resulted in an exponential increase in the number of children undergoing home mechanical ventilation (HMV) treatment. Although its efficacy in chronic respiratory failure is well established, HMV in children is more complex than that in adults, and there are more considerations. This review outlines clinical considerations for HMV in children. The goal of HMV in children is not only to correct alveolar hypoventilation but also to maximize development as much as possible. The modes of ventilation and ventilator settings, including ventilation masks, tubing, circuits, humidification, and ventilator parameters, should be tailored to the patient's individual characteristics. To ensure effective HMV, education for the parent and caregiver is important. HMV continues to change the scope of treatment for chronic respiratory failure in children in that it decreases respiratory morbidity and prolongs life spans. Further studies on this topic with larger scale and systemic approach are required to ensure the better outcomes in this population.

Helmet Ventilation for Pediatric Patients During the COVID-19 Pandemic: A Narrative Review

The air dispersion of exhaled droplets from patients is currently considered a major route of coronavirus disease 2019 (COVID-19) transmission, the use of non-invasive ventilation (NIV) should be more cautiously employed during the COVID-19 pandemic. Recently, helmet ventilation has been identified as the optimal treatment for acute hypoxia respiratory failure caused by COVID-19 due to its ability to deliver NIV respiratory support with high tolerability, low air leakage, and improved seal integrity. In the present review, we provide an evidence-based overview of the use of helmet ventilation in children with respiratory failure.

Management strategy for hematological malignancy patients with acute respiratory failure

Acute respiratory failure (ARF) is still the major cause of intensive care unit (ICU) admission for hematological malignancy (HM) patients although the advance in hematology and supportive care has greatly improved the prognosis. Clinicians have to make decisions whether the HM patients with ARF should be sent to ICU and which ventilation support should be administered. Based on the reported investigations related to management of HM patients with ARF, we propose a selection procedure to manage this population and recommend hematological ICU as the optimal setting to recuse these patients, where hematologists and intensivists can collaborate closely and improve the outcomes. Moreover, noninvasive ventilation (NIV) still has its own place for selected HM patients with ARF who have mild hypoxemia and reversible causes. It is also crucial to monitor the efficacy of NIV closely and switch to invasive mechanical ventilation at appropriate timing when NIV shows no apparent improvement. Otherwise, early IMV should be initiated to HM with ARF who have moderate and severe hypoxemia, adult respiratory distress syndrome, multiple organ dysfunction, and unstable hemodynamic. More studies are needed to elucidate the predictors of ICU mortality and ventilatory mode for HM patients with ARF.

The use of head helmets to deliver noninvasive ventilatory support: a comprehensive review of technical aspects and clinical findings

A helmet, comprising a transparent hood and a soft collar, surrounding the patient's head can be used to deliver noninvasive ventilatory support, both as continuous positive airway pressure and noninvasive positive pressure ventilation (NPPV), the latter providing active support for inspiration. In this review, we summarize the technical aspects relevant to this device, particularly how to prevent CO2 rebreathing and improve patient-ventilator synchrony during NPPV. Clinical studies describe the application of helmets in cardiogenic pulmonary oedema, pneumonia, COVID-19, postextubation and immune suppression. A section is dedicated to paediatric use. In summary, helmet therapy can be used safely and effectively to provide NIV during hypoxemic respiratory failure, improving oxygenation and possibly leading to better patient-centred outcomes than other interfaces.

Interfaces for noninvasive ventilation in the acute setting in children

The use of noninvasive ventilation (NIV) is very specific in the acute setting as compared to its use in a chronic setting. In the Pediatric Intensive care Unit (PICU), NIV may be required around the clock and initiation has to be fast and easy. Despite the increasing use of non-invasive ventilation (NIV) and the larger choice of interfaces, data comparing the use of different interfaces for pediatric patients are scarce and recommendations for the most appropriate choice of interface are lacking. However, this choice in acute settings is crucial and a major contributor of the success of NIV. The aim of the present review was to describe the different types of interfaces available for children in the acute setting, their advantages and limitations, to highlight how to choose the optimal interface, and how to monitor the tolerance of the interface.

Noninvasive support and ventilation for pediatric acute respiratory distress syndrome: proceedings from the Pediatric Acute Lung Injury Consensus Conference

OBJECTIVE

Despite the widespread use of noninvasive ventilation in children and in children with acute lung injury and pediatric acute respiratory distress syndrome, there are few scientific data on the utility of this therapy. In this review, we examine the literature regarding noninvasive positive pressure ventilation and use the Research ANd Development/University of California, Los Angeles appropriateness methodology to provide strong or weak recommendations for the use of noninvasive positive pressure ventilation in children with pediatric acute respiratory distress syndrome.

DATA SOURCES

Electronic searches were made in PubMed, EMBASE, Web of Science, Cochrane Library, and Scopus with the following specific keywords: noninvasive ventilation, noninvasive positive pressure ventilation, continuous positive airway pressure, and high-flow nasal cannula.

STUDY SELECTION

Studies were eligible for inclusion if they included 10 or more children between 1 month and 18 years old. Randomized and nonrandomized controlled trials, controlled before-and-after studies, concurrent cohort studies, interrupted time series studies, historically controlled studies, cohort studies, cross-sectional studies, and uncontrolled longitudinal studies were included for data synthesis.

DATA SYNTHESIS

The literature provides a solid physiological rationale for the use of noninvasive positive pressure ventilation in children with pediatric acute respiratory distress syndrome. The addition of noninvasive positive pressure ventilation can improve gas exchange and potentially prevent intubation and mechanical ventilation in some children with mild pediatric acute respiratory distress syndrome. Noninvasive positive pressure ventilation is not indicated in severe pediatric acute respiratory distress syndrome. Noninvasive positive pressure ventilation should be performed only in acute care setting with experienced team, and patient-ventilator synchrony is crucial for success. An oronasal interface provides superior support, but close monitoring of children is required due to the risk of progressive respiratory failure and the potential need for intubation. The use of high-flow nasal cannula is a promising treatment for respiratory disease; however, at this time, the efficacy of high-flow nasal cannula compared with noninvasive positive pressure ventilation is unknown.

CONCLUSION

Noninvasive positive pressure ventilation can be beneficial in children with pediatric acute respiratory distress syndrome, particularly in those with milder disease. However, further research is needed into the use of noninvasive positive pressure ventilation in children.

Continuous positive airway pressure with helmet versus mask in infants with bronchiolitis: an RCT

BACKGROUND

Noninvasive continuous positive airway pressure (CPAP) is usually applied with a nasal or facial mask to treat mild acute respiratory failure (ARF) in infants. A pediatric helmet has now been introduced in clinical practice to deliver CPAP. This study compared treatment failure rates during CPAP delivered by helmet or facial mask in infants with respiratory syncytial virus-induced ARF.

METHODS

In this multicenter randomized controlled trial, 30 infants with respiratory syncytial virus-induced ARF were randomized to receive CPAP by helmet (n = 17) or facial mask (n = 13). The primary endpoint was treatment failure rate (defined as due to intolerance or need for intubation). Secondary outcomes were CPAP application time, number of patients requiring sedation, and complications with each interface.

RESULTS

Compared with the facial mask, CPAP by helmet had a lower treatment failure rate due to intolerance (3/17 [17%] vs 7/13 [54%], P = .009), and fewer infants required sedation (6/17 [35%] vs 13/13 [100%], P = .023); the intubation rates were similar. In successfully treated patients, CPAP resulted in better gas exchange and breathing pattern with both interfaces. No major complications due to the interfaces occurred, but CPAP by mask had higher rates of cutaneous sores and leaks.

CONCLUSIONS

These findings confirm that CPAP delivered by helmet is better tolerated than CPAP delivered by facial mask and requires less sedation. In addition, it is safe to use and free from adverse events, even in a prolonged clinical setting.

Efficacy and predictors of success of noninvasive ventilation for prevention of extubation failure in critically ill children with heart disease

The study aimed primarily to evaluate the efficacy of noninvasive ventilation (NIV) and to identify possible predictors for success of NIV therapy in preventing extubation failure in critically ill children with heart disease. The secondary objectives of this study were to assess the efficacy of prophylactic NIV therapy initiated immediately after tracheal extubation and to determine the characteristics, outcomes, and complications associated with NIV therapy in pediatric cardiac patients. A retrospective review examined the medical records of all children between the ages 1 day and 18 years who sustained acute respiratory failure (ARF) that required NIV in the cardiovascular intensive care unit (CVICU) at Lucile Packard Children's Hospital between January 2008 and June 2010. Patients were assigned to a prophylactic group if NIV was started directly after extubation and to a nonprophylactic group if NIV was started after signs and symptoms of ARF developed. Patients were designated as responders if they received NIV and did not require reintubation during their CVICU stay and nonresponders if they failed NIV and reintubation was performed. The data collected included demographic data, preexisting conditions, pre-event characteristics, event characteristics, and outcome data. The outcome data evaluated included success or failure of NIV, duration of NIV, CVICU length of stay (LOS), hospital LOS, and hospital mortality. The two complications of NIV assessed in the study included nasal bridge or forehead skin necrosis and pneumothorax. The 221 eligible events during the study period involved 172 responders (77.8 %) and 49 nonresponders (22.2 %). A total of 201 events experienced by the study cohort received continuous positive airway pressure (CPAP), with 156 responders (78 %), whereas 20 events received bilevel positive airway pressure (BiPAP), with 16 responders (80 %). In the study, 58 events (26.3 %) were assigned to the prophylactic group and 163 events (73.7 %) to the nonprophylactic group. Compared with the nonprophylactic group, the prophylactic group experienced significantly shorter CVICU LOS (median, 49 vs 88 days; p = 0.03) and hospital LOS (median, 60 vs 103 days; p = 0.05). The CVICU LOS and hospital LOS did not differ significantly between the responders (p = 0.56) and nonresponders (p = 0.88). Significant variables identifying a responder included a lower risk-adjusted classification for congenital heart surgery (RACHS-1) score (1-3), a good left ventricular ejection fraction, a normal respiratory rate (RR), normal or appropriate oxygen saturation, prophylactic or therapeutic glucocorticoid therapy within 24 h of NIV initiation, presence of atelectasis, fewer than two organ system dysfunctions, fewer days of intubation before extubation, no clinical or microbiologic evidence of sepsis, and no history of reactive airway disease. As a well-tolerated therapy, NIV can be safely and successfully applied in critically ill children with cardiac disease to prevent extubation failure. The independent predictors of NIV success include lower RACHS-1 classification, presence of atelectasis, steroid therapy received within 24 h after NIV, and normal heart rate and oxygen saturations demonstrated within 24 h after initiation of NIV.

U.S. attitudes and perceived practice for noninvasive ventilation in pediatric acute respiratory failure

OBJECTIVE

Few pediatric studies exist regarding the use of noninvasive positive-pressure ventilation for acute respiratory failure; however, those that do suggest a role. This study seeks to describe attitudes and perceived practices of pediatric intensivists regarding the use of noninvasive positive-pressure ventilation in children with acute respiratory failure.

DESIGN

Electronic survey.

SETTING

Medical institutions.

PARTICIPANTS

Of the 932 physicians approached, 353 (38%) responded to the survey. Respondents included U.S. physicians practicing pediatric critical care (90%), pediatric anesthesia critical care (4%), pediatric pulmonary critical care (4%), and other disciplines (2%).

INTERVENTIONS

Survey.

MEASUREMENTS AND MAIN RESULTS

The survey contained questions regarding 1) practitioner demographics, 2) patient characteristics, and 3) clinical cases designed to assess noninvasive positive-pressure ventilation use in certain patient scenarios. Noninvasive positive-pressure ventilation was used by 99% of the respondents, with 60% using noninvasive positive-pressure ventilation as initial support >10% of the time. Respondents reported use of noninvasive positive-pressure ventilation for acute respiratory failure in lower airway disease (70%), asthma (51%), acute lung injury/acute respiratory distress syndrome (43%), and upper airway obstruction (31%). In clinical scenarios, respondents reported that the factors associated with nonuse of noninvasive positive-pressure ventilation as initial support were disease process (31%), oxygenation (19%), ventilation severity (15%), expectation that the patient was likely to worsen (12%), and age or inability to cooperate (11%).

CONCLUSIONS

Noninvasive positive-pressure ventilation is widely used and most frequently utilized in patients with acute lower airway disease. Factors such as severe defects in oxygenation and ventilation, disease progression, and patient tolerability decreased the likelihood of use. These findings may help direct further studies of noninvasive positive-pressure ventilation in children with acute respiratory failure.

The number of failing organs predicts non-invasive ventilation failure in children with ALI/ARDS

PURPOSE

Non-invasive positive pressure ventilation (NIV) is being increasingly used in paediatric critical care, although its use in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is still debated. No definite data are available for the prediction of NIV outcome in such selected populations. We aimed to identify which factors might affect NIV failure in paediatric ALI/ARDS patients.

METHODS

A retrospective cohort study using comprehensive predictivity analysis was performed. All children admitted to our paediatric intensive care unit over a 4-year period for ALI/ARDS were reviewed. Basic, clinical, physiological parameters and their change after 1 h of NIV were considered and subjected to univariate analysis. Candidate prognostic variables were then subjected to multicollinearity scrutiny and logistic regression. Finally, variables significant in the logistic regression were subjected to predictivity analysis.

RESULTS

The number of organ failures at admission (NOF) is a strong predictor of NIV failure (odds ratio 5.26; p = 0.004). Having only one organ failure provides a probability of NIV success of 85.7% (sensitivity 87%; specificity 49%). One NIV failure will be predicted and avoided for every four cases in which the presence of other organ failures is incorporated into the clinical decision.

CONCLUSIONS

NOF significantly predicts the NIV failure. Children with no organ failures other than ALI/ARDS may safely be treated with NIV.

Noninvasive ventilation for acute respiratory failure in children – a systematic review

ABSTRACT Objective: To assess the role of noninvasive ventilation in the treatment of children with acute respiratory failure. Methods: A systematic review of literature on noninvasive ventilation in MEDLINE, LILACS, EMBASE, and Cochrane databases, besides references in articles. The outcomes evaluated were responses in blood oxygenation and ventilation, and patient survival. Results: A total of 120 studies on noninvasive ventilation were found as of May, 2010. Of these, only 19 were about noninvasive ventilation in children. On the other hand, there are prospective and cohort clinical trials leading to a level II quality of evidence concerning the use of noninvasive ventilation in children. Conclusion: There is scientific evidence for proposing the use of noninvasive ventilation, with a B-II degree of recommendation.

Helmet-delivered heliox-CPAP in severe upper airway obstruction caused by PHACES syndrome

We present the case of a 4-month-old girl with PHACES syndrome and severe upper respiratory airway obstruction secondary to multiple subglottic and tracheal hemangiomas effectively treated with heliox-CPAP delivered by helmet (HH-CPAP).

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.

Continuous positive airway pressure ventilation with helmet in infants under 1 year

OBJECTIVE

To report the feasibility of helmet use in infants between 1 and 12 months old with acute respiratory failure.

DESIGN AND SETTING

Observations were made before and 2 h after helmet CPAP of 6 cm H(2)O. Failure was defined as recourse to intratracheal ventilation. Patient stabilization or improvement was defined as a variation <10% or a decrease >10% in one of the following: respiratory rate, inspired oxygen fraction, or capillary partial pressure of CO(2). Tolerance was assessed by the pain and discomfort score, the systematic search for pressure sores, and the measurement of helmet humidity and noise level.

RESULTS

Twenty-three infants with a median age of 5 (2-8) months were included. Helmet CPAP failed in two (9%) patients. Stability or improvement occurred in 16 (70%) patients. The pain and discomfort score was stable or improved in 22 (96%). Pressure sores were found in three (13%) infants. Humidity was 98% (98-99%) and fell to 40% (39-43%) after the humidifier was stopped. The noise level in the helmet was 81 (77-94) dB-SPL.

CONCLUSIONS

The helmet was a satisfactory interface for CPAP delivery in young infants in more than two-thirds of the cases. Pressure sores can be prevented by placing a cushion in the helmet. Caregivers need to take into account the high humidity and noise levels of this interface.

Noninvasive continuous positive airway pressure in acute respiratory failure: helmet versus facial mask

OBJECTIVE

Noninvasive continuous positive airway pressure (nCPAP) is applied through different interfaces to treat mild acute respiratory failure (ARF) in infants. Recently a new pediatric helmet was introduced in clinical practice to deliver nCPAP. The objective of this study was to compare the feasibility of the delivery of nCPAP by the pediatric helmet with delivery by a conventional facial mask in infants with ARF.

PATIENTS AND METHODS

We conducted a single-center physiologic, randomized, controlled study with a crossover design on 20 consecutive infants with ARF. All patients received nCPAP by helmet and facial mask in random order for 90 minutes. In infants in both trials, nCPAP treatment was preceded by periods of unassisted spontaneous breathing through a Venturi mask. The primary end point was the feasibility of nCPAP administered with the 2 interfaces (helmet and facial mask). Feasibility was evaluated by the number of trial failures defined as the occurrence of 1 of the following: intolerance to the interface; persistent air leak; gas-exchange derangement; or major adverse events. nCPAP application time, number of patients who required sedation, and the type of complications with each interface were also recorded. The secondary end point was gas-exchange improvement.

RESULTS

Feasibility of nCPAP delivery was enhanced by the helmet compared with the mask, as indicated by a lower number of trial failures (P < .001), less patient intolerance (P < .001), longer application time (P < .001), and reduced need for patient sedation (P < .001). For both delivery methods, no major patient complications occurred.

CONCLUSIONS

The results of this current study revealed that the helmet is a feasible alternative to the facial mask for delivery of nCPAP to infants with mild ARF.

Treatment of acute hypoxemic respiratory failure with continuous positive airway pressure delivered by a new pediatric helmet in comparison with a standard full face mask: a prospective pilot study

OBJECTIVES

To evaluate the feasibility and efficacy of continuous positive airway pressure delivered by a new pediatric helmet in comparison with a standard facial mask in infants with acute hypoxemic respiratory failure.

DESIGN

A single-center prospective case-control study.

SETTING

Pediatric intensive care unit in a tertiary children hospital.

PATIENTS AND INTERVENTIONS

Twenty consecutive infants treated with continuous positive airway pressure by a helmet matched with a control patient treated with continuous positive airway pressure by facial mask and selected by age, weight, PaO2:Fio2, and PaCO2 on pediatric intensive care unit admission.

MEASUREMENTS AND MAIN RESULTS

Feasibility was defined as the incidence of continuous positive airway pressure protocol failure secondary to 1) failure to administer continuous positive airway pressure because of intolerance to the interface; 2) deterioration in gas exchange soon after continuous positive airway pressure institution; and 3) major clinical adverse events such as pneumothorax or any hemodynamic instability related to the continuous positive airway pressure safety system device's failure. Evaluation of feasibility included also the total application time of respiratory treatment, the number of continuous positive airway pressure discontinuations/first 24 hrs. Interface-related complications included air leaks, cutaneous pressure sores, eye irritation, inhalation, and gastric distension. The 20 patients and control subjects had similar matching characteristics. Continuous positive airway pressure delivered by a helmet compared with a facial mask reduced continuous positive airway pressure trial failure rate (p = .02), increased application time (p = .001) with less discontinuations (p = .001), and was not associated with an increased rate of major adverse events, resulting in decreased air leaks (p = .04) and pressure sores (p = .002). Both continuous positive airway pressure systems resulted in early and sustained improvement in oxygenation.

CONCLUSIONS

The helmet might be considered a viable and safe alternative to a standard facial mask to deliver continuous positive airway pressure in hypoxemic infants in the pediatric intensive care unit setting. In our study, the helmet allowed more prolonged application of continuous positive airway pressure compared with a facial mask, ensuring similar improvement in oxygenation without any adverse events and clinical intolerance.

Helmet-delivered continuous positive airway pressure with heliox in respiratory syncytial virus bronchiolitis

AIM

The objective of this study was to check the feasibility and efficacy of helmet-delivered heliox-continuous positive airway pressure (CPAP) in infants with bronchiolitis.

METHODS

Children <3 months of age diagnosed with respiratory syncytial virus bronchiolitis and recurrent apnoeas or a venous PCO(2) >55 mmHg or a transcutaneous oxygen saturation <92% in room air were eligible for inclusion in the study. CPAP was delivered by a noninvasive ventilator connected to a heliox port. The interface was a helmet.

RESULTS

Eight consecutive infants fulfilled the inclusion criteria. Apnoeas were present in six children before respiratory support was started; they disappeared in five of them. Two infants had to be changed to pressure support noninvasive ventilation, and one of them required intubation. No side effects were recorded.

CONCLUSION

We propose a relatively new device to deliver heliox-CPAP in small infants with bronchiolitis. Although this is just a descriptive study with a short sample, this system seems to be feasible and effective.

Predictive factors of non invasive ventilation failure in critically ill children: a prospective epidemiological study

OBJECTIVE

Identification of predictive factors for non-invasive ventilation (NIV) failure and determination of NIV characteristics.

DESIGN

Prospective observational study.

SETTING

Paediatric Intensive Care Unit in a University Hospital.

PATIENTS AND MEASUREMENTS

A total of 116 episodes were included. Clinical data collected were respiratory rate (RR), heart rate and FiO(2) before NIV began. Same data and expiratory and support pressures were collected at 1, 6, 12, 24 and 48 h. Conditions precipitating acute respiratory failure (ARF) were classified into two groups: type 1 (38 episodes) and type 2 (78 episodes). Ventilation-perfusion impairment was the main respiratory failure mechanism in type 1, and hypoventilation in type 2. Factors predicting NIV failure were determined by multivariate analysis.

RESULTS

Most common admission diagnoses were pneumonia (81.6%) in type 1 and bronchiolitis (39.7%) and asthma (42.3%) in type 2. Complications secondary to NIV were detected in 23 episodes (20.2%). NIV success rate was 84.5% (68.4% in type 1 and 92.3% in type 2). Type 1 patients showed a higher risk of NIV failure compared to type 2 (OR 11.108; CI 95%, 2.578-47.863). A higher PRISM score (OR 1.138; CI 95%, 1.022-1.267), and a lower RR decrease at 1 h and at 6 h (OR 0.926; CI 95%, 0.860-0.997 and OR 0.911; CI 95%, 0.837-0.991, respectively) were also independently associated with NIV failure.

CONCLUSIONS

NIV is a useful respiratory support technique in paediatric patients. Type 1 group classification, higher PRISM score, and lower RR decrease during NIV were independent risk factors for NIV failure.

Physiological effects of noninvasive positive ventilation during acute moderate hypercapnic respiratory insufficiency in children

INTRODUCTION

A prospective physiological study was performed in 12 paediatric patients with acute moderate hypercapnic respiratory insufficiency to assess the ability of noninvasive positive pressure ventilation (NPPV) to unload the respiratory muscles and improve gas exchange.

MATERIALS AND METHODS

Breathing pattern, gas exchange, and inspiratory muscle effort were measured during spontaneous breathing and NPPV.

RESULTS

NPPV was associated with a significant improvement in breathing pattern, gas exchange and respiratory muscle output. Tidal volume and minute ventilation increased by 33 and 17%, and oesophageal and diaphragmatic pressure time product decreased by 49 and 56%, respectively. This improvement in alveolar ventilation translated into a reduction in mean partial pressure in carbon dioxide from 48 to 40 mmHg (P = 0.01) and in respiratory rate from 48 to 41 breaths/min (P = 0.01). No difference between a clinical setting and a physiological setting of NPPV was observed. In conclusion, this study shows that NPPV is able to unload the respiratory muscles and improve clinical outcome in young patients admitted to the paediatric intensive care unit for acute moderate hypercapnic respiratory insufficiency.

Noninvasive ventilation in large postoperative flail chest

An 11-year-old male developed a severe respiratory failure due to a iatrogenic flail chest following a surgery for removing a large chest wall area. A rare Ewing sarcoma was histologically diagnosed and intensive chemotherapy was administered. Postoperatively, because of the failure in ventilation weaning, the patient was electively extubated and noninvasive positive pressure ventilation through face-mask was provided. Respiratory support avoided asynchronous paradoxical movements and achieved pneumatic stabilization. Clinical and respiratory improvement allowed a successful weaning from ventilator.

[Interfaces for pediatric noninvasive ventilation (excluding neonate)]

The quality of noninvasive ventilation in pediatrics is interface-dependent. Several types of interfaces are currently available: nasal and oral masks, nasal pillows and helmets. Despite material improvements in material design, shape, size and components, interfaces are still not adapted for most children. The ideal interface must fit the child's characteristics and the disease requirements. For instance, a nasal canula is recommended for infants younger than 3 months of age. If necessary, nasal masks can be used as oronasal masks. Repeated and careful evaluations are indicated to ensure interface adequacy and to detect cutaneous injuries and facial deformities. Training is required for medical and paramedical personnel. Pediatrics studies, comparing interfaces, are needed to build evidence-based recommendations.

Carbon dioxide rebreathing during non-invasive ventilation delivered by helmet: a bench study

OBJECTIVE

To define how to monitor and limit CO(2) rebreathing during helmet ventilation.

DESIGN

Physical model study.

SETTING

Laboratory in a university teaching hospital.

INTERVENTIONS

We applied pressure-control ventilation to a helmet mounted on a physical model. In series 1 we increased CO(2) production (V'CO(2)) from 100 to 550 ml/min and compared mean inhaled CO(2) (iCO(2),mean) with end-inspiratory CO(2) at airway opening (eiCO(2)), end-tidal CO(2) at Y-piece (yCO(2)) and mean CO(2) inside the helmet (hCO(2)). In series 2 we observed, at constant V'CO(2), effects on CO(2) rebreathing of inspiratory pressure, respiratory mechanics, the inflation of cushions inside the helmet and the addition of a flow-by.

MEASUREMENTS AND RESULTS

In series 1, iCO(2),mean linearly related to V'CO(2). The best estimate of CO(2) rebreathing was provided by hCO(2): differences between iCO(2),mean and hCO(2), yCO(2) and eiCO(2) were 0.0+/-0.1, 0.4+/-0.2 and -1.3+/-0.5%. In series 2, hCO(2) inversely related to the total ventilation (MVtotal) delivered to the helmet-patient unit. The increase in inspiratory pressure significantly increased MVtotal and lowered hCO(2). The low lung compliance halved the patient:helmet ventilation ratio but led to minor changes in MVtotal and hCO(2). Cushion inflation, although it decreased the helmet's internal volume by 33%, did not affect rebreathing. A 8-l/min flow-by effectively decreased hCO(2).

CONCLUSIONS

During helmet ventilation, rebreathing can be assessed by measuring hCO(2) or yCO(2), but not eiCO(2). It is directly related to V'CO(2), inversely related to MVtotal and can be lowered by increasing inspiratory pressure or adding a flow-by.

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.

Changes in outcomes (1996-2004) for pediatric oncology and hematopoietic stem cell transplant patients requiring invasive mechanical ventilation

OBJECTIVE

To assess the following hypotheses regarding mechanically ventilated pediatric oncology patients, including those receiving hematopoietic stem cell transplant (HSCT) and those not receiving HSCT: 1) outcomes are more favorable for nontransplant oncology patients than for those requiring HSCT; 2) outcomes have improved for both populations over time; and 3) there are factors available during the time of mechanical ventilation that identify patients with a higher likelihood of dying.

DESIGN

Retrospective review.

SETTING

Free-standing, tertiary care, pediatric hematology oncology hospital.

PATIENTS

All patients requiring invasive mechanical ventilation with a diagnosis of cancer or following HSCT from January 1996 to December 2004.

INTERVENTIONS

Bivariate and multivariate analysis. Dates of admission were grouped into time periods for analysis: 1996-1998, 1999-2001, and 2002-2004.

MEASUREMENTS AND MAIN RESULTS

There were 401 courses of mechanical ventilation (329 patients) analyzed. Forty-five percent of HSCT admissions (92 of 206) vs. 75% of non-HSCT oncology admissions (146 of 195) were extubated and discharged from the pediatric intensive care unit (p < .0001). Twenty-five percent of HSCT vs. 60% of non-HSCT admissions survived 6 months (p < .0001). Among admissions with an abnormal chest radiograph and a PaO2/FiO2 ratio <200, pediatric intensive care unit survival increased for each successive time period, with 45% of HSCT and 83% of non-HSCT admissions surviving during 2002-2004. In multivariate analysis of all study patients, Pediatric Risk of Mortality scores on the day of intubation, allogeneic HSCT, cardiovascular failure, hepatic failure, neurologic failure, a previous course of mechanical ventilation within 6 months, and the time period intubated were associated with mortality. With the exception of time period, these same variables were associated with mortality in multivariate analysis of only HSCT patients.

CONCLUSIONS

HSCT patients who require mechanical ventilation have worse outcomes than non-HSCT oncology patients. Outcomes for both groups have improved over time. Allogeneic transplant, higher Pediatric Risk of Mortality scores, need for repeated mechanical ventilation, and concomitant organ system dysfunction are risk factors for death.

Continuous positive airway pressure with modified helmet for treatment of hypoxemic acute respiratory failure in infants and a preschool population: a feasibility study

OBJECTIVE

To analyze the feasibility of using continuous positive airway pressure (CPAP) delivered via a modified helmet to treat children with hypoxemic acute respiratory failure.

DESIGN

A single-center, prospective, clinical study.

SETTING

Pediatric intensive care unit in a university hospital.

PATIENTS

Fifteen consecutive children (from 1 month to 5 yrs of age) with hypoxemic acute respiratory failure (defined as Pao2/Fio2 <300).

INTERVENTIONS

CPAP was delivered via a modified helmet (CaStar, Starmed, Italy) of reduced size, fastened by a device we call a "baby-body." The feasibility of CPAP with the helmet was the primary end point. The improvement of gas exchange was the secondary one.

MEASUREMENTS AND MAIN RESULTS

Ten of 15 children had multiple organ failure. Nine of 15 children were </=1 yr old. The helmet was well tolerated by all the children. Additional sedation was provided to four patients. No children developed significant complications (skin lesion, gastric distension, conjunctivitis, epistaxis, or loss of invasive devices) or lethal, helmet-related events. Oxygenation improved above baseline after 2 hrs of CPAP with the helmet; no significant variation of hemodynamic variables was detected.

CONCLUSIONS

The helmet is a suitable device for delivery of CPAP to infants and preschool children with hypoxemic acute respiratory failure. It was well tolerated and improved oxygenation.

Physiologic evaluation of different levels of assistance during noninvasive ventilation delivered through a helmet

OBJECTIVE

To evaluate the effects of various levels of pressure support (PS) during noninvasive ventilation delivered through a helmet on breathing pattern, inspiratory effort, CO2 rebreathing, and comfort.

DESIGN

Physiologic study.

SETTING

University-affiliated hospital.

PATIENTS AND PARTICIPANTS

Eight healthy volunteers.

INTERVENTIONS

Volunteers received ventilation through a helmet with four different PS/positive end-expiratory pressure combinations (5/5 cm H2O, 10/5 cm H2O, 15/5 cm H2O, and 10/10 cm H2O) applied in random order.

MEASUREMENTS AND RESULTS

The ventilatory respiratory rate, esophageal respiratory rate (RRpes), airway pressure, esophageal pressure tracings, esophageal swing, and pressure-time product (PTP) [PTP per breath, PTP per minute, and PTP per liter] were evaluated. We also measured the partial pressure of inspired CO2 (Pi(CO2)) at the airway opening, mean partial pressure of expired CO2 (Pe(CO2)), CO2 production (V(CO2)), minute ventilation (V(E)) delivered to the helmet (V(E)h), and the true inspired V(E). By subtracting V(E) from V(E)h, we obtained the Ve washing the helmet (V(E)wh). A visual analog scale (from 0 to 10) was used to evaluate comfort. Compared to spontaneous breathing, different levels of PS progressively increased tidal volume (V(T)) and decreased RRpes, reducing inspiratory effort. The increased levels of assistance did not produce significant changes in Pi(CO2), end-tidal CO2, and V(CO2). Pe(CO2) had a slight decrease when increasing the level of PS from 5 to 10 cm H2O (p < 0.05). Despite the presence of constant values of Ve, the increase of PS produced an increase in V(E)wh, without significant differences comparing 10 cm H2O and 15 cm H2O of PS. The subjects had a slight but not significant increase in discomfort by augmenting the level of assistance. At the highest level of PS (15 cm H2O), the discomfort was significantly higher (p < 0.001) than at the other levels of assistance.

CONCLUSION

In volunteers, the helmet is efficient in ventilation, allowing a Vt increase and RRpes reduction. A significant discomfort was present only at the highest level of assistance; however, it did not affect patient/ventilator interaction.

Effectiveness of mask and helmet interfaces to deliver noninvasive ventilation in a human model of resistive breathing

The helmet, a transparent latex-free polyvinyl chloride cylinder linked by a metallic ring to a soft collar that seals the helmet around the neck, has been recently proposed as an effective alternative to conventional face mask to deliver pressure support ventilation (PSV) during noninvasive ventilation in patients with acute respiratory failure. We tested the hypothesis that mechanical characteristics of the helmet (large internal volume and high compliance) might impair patient-ventilator interactions compared with standard face mask. Breathing pattern, CO2 clearance, indexes of inspiratory muscle effort and patient-ventilator asynchrony, and dyspnea were measured at different levels of PSV delivered by face mask and helmet in six healthy volunteers before (load-off) and after (load-on) application of a linear resistor. During load-off, no differences in breathing pattern and inspiratory muscle effort were found. During load-on, the use of helmet to deliver pressure support increased inspiratory muscle effort and patient-ventilator asynchrony, worsened CO2 clearance, and increased dyspnea compared with standard face mask. Autocycled breaths accounted for 12 and 25% of the total minute ventilation and for 10 and 23% of the total inspiratory muscle effort during mask and helmet PSV, respectively. We conclude that PSV delivered by helmet interface is less effective in unloading inspiratory muscles compared with PSV delivered by standard face mask. Other ventilatory assist modes should be tested to exploit to the most the potential benefits offered by the helmet.

Noninvasive ventilation options in pediatric myasthenia gravis

A 10-month-old female infant with congenital myasthenic syndrome suffering from acute respiratory failure was supported using face mask positive pressure ventilation until definitive diagnosis and specific treatment was achieved. A 12-year-old girl suffering from seronegative myasthenia gravis was treated by helmet-delivered noninvasive ventilation during recurrent myasthenic episodes. Noninvasive support was really beneficial in the myasthenic crisis with respiratory muscle weakness, whereas a shift to tracheal intubation was necessary when pulmonary infection and multiple atelectasis occurred. The new helmet interface for noninvasive positive pressure ventilation can represent a valuable means of respiratory support in the early phase of respiratory failure in older children.

Pediatric acute lung injury: prospective evaluation of risk factors associated with mortality

RATIONALE

The 1994 American European Consensus Committee definitions of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) have not been applied systematically in the pediatric population.

OBJECTIVES

The purpose of this study was to evaluate prospectively the epidemiology and clinical risk factors associated with death and prolonged mechanical ventilation in all pediatric patients admitted to two large, pediatric intensive care units with ALI/ARDS using Consensus criteria.

METHODS

All pediatric patients meeting Consensus Committee definitions for ALI were prospectively identified and included in a relational database.

MEASUREMENTS AND MAIN RESULTS

There were 328 admissions for ALI/ARDS with a mortality of 22%. Multivariate logistic regression analyses revealed (1) the initial severity of oxygenation defect, as measured by the Pa(O2)/FI(O2) ratio; (2) the presence of nonpulmonary and non-central nervous system (CNS) organ dysfunction; and (3) the presence of CNS dysfunction were independently associated with mortality and prolonged mechanical ventilation. A substantial fraction of patients (28%) did not require mechanical ventilation at the onset of ALI; 46% of these patients eventually required intubation for worsening ALI.

CONCLUSIONS

Mortality in pediatric ALI/ARDS is high and several risk factors have major prognostic value. In contrast to ALI/ARDS in adults, the initial severity of arterial hypoxemia in children correlates well with mortality. A significant fraction of patients with pediatric ALI/ARDS can be identified before endotracheal intubation is required. These patients provide a valuable group in whom new therapies can be tested.

Cytotoxic chemotherapy administered to two patients with partially refractory leukaemia while receiving intensive care treatment

Administration of cytotoxic chemotherapy to a mechanically ventilated patient is a major undertaking. Induction of remission of leukaemia under such circumstances is an extremely rare event. We report two patients with partially refractory acute myeloid leukaemia who achieved remission of their leukaemia after receiving chemotherapy in the intensive care unit. Both patients were subsequently cured by allogeneic bone marrow transplant.