Comparing the efficacy of nebulizer recombinant human DNase and hypertonic saline as monotherapy and combined treatment in the treatment of persistent atelectasis in mechanically ventilated newborns

Mucus Clearance Strategies in Mechanically Ventilated Patients

The use of airway clearance strategies as supplementary treatment in respiratory disease has been best investigated in patients with cystic fibrosis (CF) and non-cystic fibrosis bronchiectasis (NCFBE), conditions which are traditionally characterized by excessive mucus stasis and mucociliary dysfunction. A variety of airway clearance therapies both pharmacological and non-pharmacological have been shown to ameliorate disease progression in this population and have hence been assimilated into routine respiratory care. This self-propagating cycle of mucus retention and airway damage leading to chronic inflammation and infections can also be applied to patients with respiratory failure requiring mechanical ventilation. Furthermore, excessive trachea-bronchial secretions have been associated with extubation failure presenting an opportunity for intervention. Evidence for the use of adjunctive mucoactive agents and other therapies to facilitate secretion clearance in these patients are not well defined, and this subgroup still remains largely underrepresented in clinical trials. In this review, we discuss the role of mucus clearance techniques with a proven benefit in patients with CF and NCFBE, and their potential role in patients requiring mechanical ventilation while highlighting the need for standardization and adoption of mucus clearance strategies in these patient populations.

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.

Clinical Efficacy and Safety of Mechanical Ventilation Combined with Fiberoptic Bronchoalveolar Lavage in Patients with Severe Pulmonary Infection

Background

The aim of this study was to assess the clinical efficacy and safety of mechanical ventilation combined with fiberoptic bronchoalveolar lavage in patients with severe pulmonary infection.

Material/Methods

We randomly divided 81 patients with severe pulmonary infection into a control group (n=40) and an observation group (n=41). Both groups were treated using mechanical ventilation, and observation group additionally received assistive fiberoptic bronchoalveolar lavage.

Results

The cure rate and effectiveness rate in the observation group were higher than in the control group (P<0.05, χ²=3.2), and the incidence of ventilator-associated pneumonia in the observation group was significantly lower than that in the control group (P<0.05, χ²=9.4). The partial pressure of oxygen (PaO₂) and oxygen saturation (SaO₂) were higher in the observation group than in the control group (P<0.05, t=3.862, t=33.595), whereas the partial pressure of carbon dioxide (PaCO₂) and respiratory rate were lower in the observation group than in the control group (P<0.05, t=3.307, t=5.043). The levels of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8) in the 2 groups were lower after treatment than before treatment (all P<0.05), and the levels in the observation group were lower than those in the control group (all P<0.05). Hospital stay, infection control window appearance time, invasive mechanical ventilation time, and total mechanical ventilation time in the observation group were shorter than those in the control group (P<0.05, t=13.990, t=8.643, t=9.717, t=8.980).

Conclusions

Mechanical ventilation combined with fiberoptic bronchoalveolar lavage can effectively improve the curative effects and the blood gas and inflammation indicators in patients.

Recombinant Human Deoxyribonuclease I

Human deoxyribonuclease I (DNase I) is an endonuclease that catalyzes the hydrolysis of extracellular DNA and is just one of the numerous types of nucleases found in nature. The enzymatic mechanism for a single turnover is reasonably well understood based on biochemical and structural studies that are consistent with divalent metal ion dependent nonspecific nicking of a phosphodiester bond in one of the strands of double stranded DNA. Recombinant human DNase I (rhDNase I, rhDNase, Pulmozyme^®, dornase alfa) has been expressed in mammalian cell culture in Chinese hamster ovary cells and developed clinically where it is aerosolized into the airways for treatment of pulmonary disease in patients with cystic fibrosis (CF). rhDNase I hydrolyzes the DNA in purulent sputum of CF patients and reduces sputum viscoelasticity. Reduction of high molecular weight DNA into smaller fragments by treatment with aerosolized rhDNase I has been proposed as the mechanism to reduce the mucus viscosity and improve mucus clearability from obstructed airways in patients. The improved clearance of the purulent mucus enhances pulmonary function and reduces recurrent exacerbations of respiratory symptoms. rhDNase I was approved for clinical use in 1993 and has been widely used as a safe and effective therapy for CF patients. The use of rhDNase I has also been investigated in other diseases where exogenous DNA has been implicated in the disease pathology.

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 roles of drug therapy given via the endotracheal tube to neonates

Many drugs are given to intubated neonates by the inhalation route. The optimum aerosol delivery system, however, has not been identified and there are many challenges in delivering drugs effectively to the lower airways of intubated neonates. The effectiveness of surfactant in prematurely born infants and nitric oxide has been robustly investigated. Other drugs are being used on very limited evidence.

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.