Recombinant human deoxyribonuclease improves atelectasis in mechanically ventilated children with cardiac disease

Chest physiotherapy for mechanically ventilated children: a survey of current UK practice

OBJECTIVES

Chest physiotherapy is a treatment option for mechanically ventilated children. However, there is a lack of consensus regarding its value and informal discussions suggest variation in practice. This study describes chest physiotherapy practices for mechanically ventilated children in the UK and explores clinical decision making related to its delivery.

DESIGN

Cross-sectional study, using an anonymous, electronic survey.

PARTICIPANTS

Qualified physiotherapists working in UK NHS paediatric intensive care units (PICUs).

RESULTS

The response rate was 61% (72/118), this included physiotherapists from 26/27 (96%) PICUs. All participants reported using manual hyperinflations and position changes 'always' or 'often'. Variation in practice was evident for some techniques, including Metaneb® and percussion. DNase (99%, 71/72) and hypertonic saline (90%, 65/72) were the most frequently used mucoactives: 91% (59/65) of physiotherapists reported only nebulising hypertonic saline and 69% (49/71) use both nebulised and instilled DNase. Use and delivery of N-acetylcysteine was inconsistent (nebulised only 55%, 26/47; instilled only 15%, 7/47; both 30%, 14/47). Chest physiotherapy was most commonly delivered with a nurse (67%, 48/72). Clinical decision making processes were comparable between physiotherapists and encompassed three main elements: individual patient assessment, involvement of the multidisciplinary team, and risk versus benefit analysis.

CONCLUSIONS

A range of chest physiotherapy treatments and adjuncts were used with ventilated children. Variation was apparent and may be due to individual preferences of those training staff or local policies. Pragmatic, interventional studies are required to determine best practice. Further exploration is necessary to understand the variation in practice and intricacies of decision making.

Use of recombinant human deoxyribonuclease in pediatric intensive care unit - a single-center experience

OBJECTIVE

Dornase alfa (rhDNase) reduces the viscosity of purulent sputum in the lungs. The use in patients with cystic fibrosis (CF) is proven. However, the evidence of its applicability to other conditions is limited. This study aims to present the authors' experience with the use of rhDNase in non-CF patients admitted to the Pediatric Intensive Care Unit (PICU). At the study center, rhDNase was used during flexible bronchoscopies in 24 cases, of which 20 (83%) had atelectasis and seven (29%) were admitted to PICU. Four patients (57%) were on invasive mechanical ventilation (MV).

CASE DESCRIPTION

Two cases of daily rhDNase administration at PICU are presented: patient A was an 8-year-old boy admitted with septic shock and acute respiratory distress syndrome (ARDS). The patient required mechanical ventilation with aggressive settings and experienced several clinical complications. On D50, he started rhDNase treatment with an improvement in FiO2, PaCO2 and PaO2/FiO2 ratio according to radiologic findings. He was extubated on D23 of treatment.Patient B was a 17-month-old girl admitted with a convulsive status epilepticus who experienced respiratory complications (infectious and barotrauma) with ARDS, requiring aggressive ventilation. She initiated rhDNase treatment on D60. During the treatment an improvement in FiO2, PaO2/FiO2 ratio and a tendency of PaCO2 decrease were found. She had radiological improvement. No complications were described.

COMMENTS

RhDNase may be a helpful and safe tool to use in PICU prolonged intubated patients with ventilator-induced lung injury. Further studies are needed to assess and propose valid indications.

A Novel Maneuver to Treat Refractory Atelectasis in Mechanically Ventilated Children

We developed a novel airway clearance and lung recruitment maneuver for children with refractory unilateral atelectasis undergoing invasive mechanical ventilation. In this retrospective, single-center, proof of concept study, we describe the steps involved in this novel maneuver and evaluate its effectiveness in 15 patients through objective quantitation of changes in respiratory system compliance and in the degree of atelectasis assessed by a validated Modified Radiology Atelectasis Score. Compared with the premaneuver baseline, the median atelectasis score improved significantly following the maneuver (9 [7.5–10] vs. 1 [0–3.3], respectively, p < 0.01). Likewise, dynamic compliance was significantly higher following the maneuver (0.3 [0.32–0.44] vs. 0.61 [0.53–0.69] mL/kg/cm H2O, respectively, p < 0.01). No patients required a bronchoscopy. This simple and effective maneuver resulted in a significant improvement in the degree of atelectasis and dynamic compliance in this cohort of mechanically ventilated children with refractory unilateral atelectasis.

Use of dornase alfa in the paediatric intensive care unit: current literature and a national cross-sectional survey

Objectives

Airway mucus obstruction is a major challenge in children admitted to the paediatric intensive care unit (PICU). We aimed to evaluate the evidence and contemporary use of the mucolytic medication dornase alfa for non-cystic fibrosis conditions in the PICU.

Methods

(1) We performed a systematic review with searches in PubMed, EMBASE, and the Cochrane Library. Study selection: for quality assessment and data synthesis, we included only randomised controlled trials (RCTs) that compared dornase alfa to standard care or placebo in critically-ill paediatric patients (<18 years of age) in the PICU. However, non-randomised controlled studies and case series are also discussed. Data extraction: data were extracted independently by multiple reviewers using data extraction forms. The primary outcome was duration of mechanical ventilation. Data synthesis: The GRADE approach was used for quality assessment. No meta-analysis could be performed. (2) A national cross-sectional survey among all seven PICUs in the Netherlands was also performed.

Results

The systematic review yielded only one RCT, comparing dornase alfa with normal saline in children after cardiac surgery. In this study, dornase alfa led to a reduction in duration of mechanical ventilation by approximately 1 day (36% reduction). In addition, we found nine retrospective observational and case studies. The survey revealed high current use of dornase alfa in Dutch PICUs: 42% of the respondents reported prescribing dornase alfa at least once every week. Only 4% of the respondents reported having access to a local PICU dornase alfa protocol.

Conclusions

The off-label use of dornase alfa in the PICU is frequent without strong evidence or local protocols, highlighting the need for further research on the effectiveness of this mucolytic agent.

The respiratory system in pediatric chronic heart disease

Cardiovascular disease in the pediatric population closely affects the respiratory system inducing water retention in the lungs and pulmonary edema, airway compression by cardiovascular structures, restrictive pulmonary physiology as a result of hemodynamic changes and surgical repair, susceptibility to respiratory infections, development of pulmonary hypertension, thrombosis, or hemorrhage. Chronic heart failure and congenital heart disease are characterized by various respiratory manifestations and symptoms mimicking lung disease, which are frequently difficult to diagnose and treat. Pulmonary function is multiply affected in pediatric heart disease with mostly restrictive but also obstructive and diffusion abnormalities. Patients with Fontan circulation represent a separate group with slow, passive pulmonary blood flow and distinct pathophysiology with low cardiac output heart failure, restrictive lung pattern, increased thromboembolic complications and rare conditions such as protein losing enteropathy and plastic bronchitis. Distinguishing between cardiovascular and pulmonary symptoms may be challenging in the growing population of pediatric and adult survivors of congenital heart disease and understanding of the relationship of the two systems in heart disease is crucial for the optimal management of these patients.

The use of pulmonary clearance medications in the acutely ill patient

INTRODUCTION

Retention of airway secretions occurs in disease, leading to airway plugging, atelectasis, and worsened respiratory mechanics, making airway clearance an important therapeutic target. Areas covered: Many medications designed to enhance clearance of airway secretions are available. We will review the medications available to enhance airway clearance, their mechanisms of action, and the evidence available for their use in acutely ill patients. Expert commentary: In the cystic fibrosis (CF) population, beneficial effects have been shown in pulmonary function with the use of some of these agents. In the non-CF population, there is limited evidence regarding these medications. While some studies have found benefit, the quality of evidence is low, making it difficult to draw conclusions. While certain patients may derive benefit, the general use of these medications in acutely ill patients without CF cannot be recommended at this time.

The role of mucoactive agents in the mechanically ventilated patient: a review of the literature

INTRODUCTION

The management of airway secretions in the mechanically ventilated patient is a routine task throughout all intensive care units. The current treatment strategies are primarily based on anecdotal experiences rather than statistical evidence. Areas covered: This review article evaluates the data from published trials surrounding mucoactive agents and their use in the critically ill patient population. We completed an extensive search through PUBMED and CINAHL via EBSCO, along with the Cochran library to find all trials using mucoactive agents in the critically ill patient population. Expert commentary: Overall, the role of mucoactive agents in the intensive care unit is a field within pulmonary critical care that is in need of evidence-based recommendations. We feel that there is great opportunity for investigators to evaluate different mucoactive therapies in this patient population and to determine their effect on clinical outcomes.

Mucolytics for intubated asthmatic children: a national survey of United kingdom paediatric intensive care consultants

Aim. The extent to which mucolytics are utilised in mechanically ventilated asthmatic children is unknown. We sought to establish current practice in the United Kingdom (UK) including choice of mucolytic, dose, and frequency of utilisation. Methods. A national electronic survey was distributed to UK consultants during April and May 2014. We were able to identify 168 PICU consultants at 25 institutions to whom we were able to electronically distribute a survey, representing an estimated 81% of UK NHS PICU consultants. Results. Replies were received from 87 consultants at 21 institutions (response rate = 52%). Recombinant human DNase (rhDNase) does get administered by 63% of clinicians, with 54% and 19% that administer hypertonic saline or N-acetylcysteine, respectively. Of those that do administer rhDNase the majority (48%) dilute it with 0.9% saline and blindly administer it, whereas 35% administer rhDNase under bronchoscopic guidance and 17% judge the necessity for bronchoscopy according to clinical severity. 25 respondents described 7 different methods to calculate rhDNase dose. A majority (87%) of respondents expressed an interest to consider enrolling patients into an RCT that evaluates rhDNase. Conclusion. Significant variation exists regarding the necessity for mucolytics, choice of agent, optimal route, and dose in intubated asthmatic children.

Dornase Alfa for Non–Cystic Fibrosis Pediatric Pulmonary Atelectasis

Objective: To review the literature evaluating the efficacy of dornase alfa for non–cystic fibrosis pediatric patients with pulmonary atelectasis. Data Sources: Articles were retrieved after a search of MEDLINE/PubMed (1946 to April 2014), and International Pharmaceutical Abstracts (1970-April 2014) was performed using the terms dornase alfa, recombinant human deoxyribonuclease, pulmonary, persistent, and atelectasis. Other relevant articles referenced from the MEDLINE search were also utilized. Study Selection and Data Extraction: Data sources were limited to English language clinical trials and case studies including only children; 8 clinical trials and 12 case reports met the criteria. Data Synthesis: Dornase alfa is used as an off-label treatment option for pulmonary atelectasis because limited treatment modalities exist after conventional therapy has failed. We evaluated 8 clinical trials and 12 case reports involving this pediatric population with varying primary diagnoses. The majority of patients experienced improvement in atelectasis, suggesting benefit after receiving treatment with dornase alfa. However, the outcomes were possibly confounded by those receiving combination therapies, varying primary diagnoses, and varying end points evaluated. Dornase alfa was overall well tolerated, with only a few patients experiencing worsening atelectasis posttreatment. Conclusions: Dornase alfa may be considered as a therapeutic option in non–cystic fibrosis pediatric patients with pulmonary atelectasis, who require treatment intervention when conventional therapy is unsuccessful.

DNA and inflammatory mediators in bronchoalveolar lavage fluid from children with acute inhalational injuries

The aim of this study was to assess the feasibility of using serial bronchoalveolar lavage fluids (BALFs) to characterize the course of cell damage and inflammation in the airways of pediatric patients with acute burn or inhalation injury. This was a prospective, longitudinal, descriptive pilot study conducted at the Burn and Pediatric Intensive Care Units in a tertiary care medical center. Six consecutively intubated and mechanically ventilated pediatric patients with acute inhalational injuries were studied. Serial BALF specimens from clinically indicated bronchoscopies were used to measure DNA and cytokine levels. BALF DNA levels for the six pediatric burn subjects were the highest within the first 72 hours after burn injury and declined thereafter. At the early stages after injury, BALF DNA levels (median [min, max] 3789 [1170, 11,917] ng/ml) were similar to those in adult burn patients and pediatric cystic fibrosis or bronchiectasis patients and was higher than those in pediatric recurrent pneumonia patients. BALF DNA levels in children and adults with inhalation injury correlated significantly with BALF interleukin-6, interleukin-8, and transforming growth factor-β1 levels. The patient with the most severe early visible airway mucosal damage and soot pattern at bronchoscopy, as well as the most extensive burns, also had the highest average early BALF DNA level (11,917 ng/ml) and the longest ventilator course and hospital stay. Procedures were well tolerated. In children with acute burn and inhalational injury, airway cellular damage and inflammation (reflected in high BALF DNA levels) appear to peak during the first 72 hours after burn or inhalation injury followed by a slow decline. Serial analysis of factors in airway secretions is feasible and has the potential to reveal important pathophyisiologic pathways and therapeutic targets for the treatment of acute inhalational injuries.