Respiratory Support Strategies Research Articles

Tidal Volume Delivery and Endotracheal Tube Leak during Cardiopulmonary Resuscitation in Intubated Newborn Piglets with Hypoxic Cardiac Arrest Exposed to Different Modes of Ventilatory Support

Background: There are few data available on the interaction of inflations, chest compressions (CC), and delivery of tidal volumes in newborn infants undergoing resuscitation in the presence of endotracheal tube (ET) leaks. Objectives: To determine the effects of different respiratory support strategies along with CC on changes in tidal volume and ET leaks in hypoxic newborn piglets with cardiac arrest. Methods: Asphyxiated newborn piglets, intubated with weight-adapted uncuffed ET, were randomized into three groups and resuscitated according to ILCOR 2010 guidelines: (1) T-piece resuscitator (TPR) group = peak inspiratory pressure (PIP)/positive end-expiratory pressure (PEEP) 25/5 cm H₂O, rate 30/min, inflations interposed between CC (3:1 ratio); (2) self- inflating bag (SIB) group = PIP 25 cm H₂O without PEEP, rate 30/min, inflations interposed between CC (3:1 ratio), and (3) ventilator group = PIP/PEEP of 25/5 cm H₂O, rate 30/min. CC were applied with a rate of 120/min without synchrony to inflations. Results: We observed a significant increase of leak (average increase 11.4%) when CC was added to respiratory support (p = 0.0001). Expired tidal volume was larger in the SIB group than in the two other modes which both applied PEEP. However, tidal volumes caused by CC only were larger in the two groups with PEEP than in the SIB group (without PEEP). Conclusions: There is interaction between lung inflations and CC affecting leak and delivery of tidal volume, which may be influenced by the mode/device used for respiratory support. Leak is larger in the presence of PEEP. However, CC cause additional tidal volume which is larger in the presence of PEEP.

Research progress of ventilator-induced diaphragmatic dysfunction

Background Mechanical ventilation is one of the most common clinical respiratory support strategies. However, prolonged mechanical ventilation can cause diaphragmatic atrophy and contraction dysfunction, namely ventilaor-induced diaphragmatic dysfunction(VIDD), which is related to weaning failure of critically ill patients. Objective The pathogenesis of VIDD is complex and it is still lack of effective prevention and control strategies in clinical treatment. The current article reviewed the mainly related mechanisms, especially the early starting and regulating mechanisms as well as the prevention and treatment measures of VIDD, looking for potential research breakthrough. Content This article described research backgrounds, pathophysiological alterations, mechanisms and prevention measures of VIDD. Trend The precise mechanisms and effective prevention measures of VIDD still need further researches to clarify. Key words: Mechanical ventilation; Diaphragm; Dysfunction

Bronchopulmonary Dysplasia Within and Beyond the Neonatal Unit.

Bronchopulmonary dysplasia (BPD), also known as chronic lung disease of prematurity or chronic neonatal lung disease, is a major cause of respiratory illness in premature babies. Newborn babies survive at gestational ages of 23 to 26 weeks, earlier than when BPD was first described. New mechanisms of lung injury have therefore emerged and the clinical and pathological characteristics of pulmonary involvement have changed. Improved neonatal intensive care unit modalities have increased survival rates; the overall prevalence of the condition, however, has not changed. Management of evolving BPD aims at minimizing lung injury. Management of established, especially severe BPD, still poses significant clinical challenge as these babies need long-term oxygen therapy (LTOT) for variable length of time. We aim to give an overview of management of established BPD with particular focus on weaning home oxygen therapy at our local center in the United Kingdom. On the basis of most recent evidence, we concluded that an integrated pathway for managing babies on LTOT is very important after discharge from neonatal unit. A structured weaning pathway for premature babies on home oxygen improves outcome. The management of severe BPD and related complications, particularly during the first 2 years of life, remains a continuing challenge for parents and healthcare providers. The most beneficial respiratory support strategy to minimize lung injury and/or promote lung healing remains unclear and requires further investigation.

Advances in the support of respiratory failure: putting all the evidence together.

Considerable progress has been made recently in the understanding of how best to accomplish safe and effective ventilation of patients with acute lung injury. Mechanical and nonmechanical factors contribute to causation of ventilator-associated lung injury. Intervention timing helps determine the therapeutic efficacy and outcome, and the stage and severity of the disease process may determine the patient's vulnerability as well as an intervention's value. Reducing oxygen consumption and ventilatory demands are key to a successful strategy for respiratory support of acute respiratory distress syndrome. Results from major clinical trials can be understood against the background of the complex physiology of ventilator-induced lung injury.

Impact of new methods of respiratory support on postoperative restrictive syndrome and gas exchange after ventral hernias plasty

The concept of respiratory support in anesthesiology underwent significant changes for last decade. The aim of these changes was the decrease of frequency of postoperative pulmonary dysfunction development. In the research was considered an impact of the new strategies of respiratory support on the state of external respiration and pulmonary gas exchange in early postoperative period at large and giant ventral hernias plasty.Methods. 77 patients underwent the prospective clinical examination after nonstrain methods of ventral hernias plasty. Patients receive the standard respiratory support in postoperative period, lung recruitment maneuver (RM) 40/10 and positive end-expiratory pressure (РЕЕР) 7–10 sm. water column, postoperative constant positive airway pressure (СРАР). There were studied the next parameters: oxygen saturation of arterial blood (SpO2), partial oxygen pressure in arterialized capillary blood (PaO2), gradient of carbon dioxide end-expiratory partial pressure in arterialized capillary blood (Р(а-et)CO2)), respiratory volume (RV), forced vital capacity (FVC)of lungs. The Kruskal-Wollis method with Mann-Whitney criterion assessment was used at intergroup analysis. Statistical analysis - STATISTICA AS for Windows (version 5.5).Results. Statistical analysis demonstrated statistically significant (р<0,05) increase of oxygenation parameters (SpO2 , PaO2), spirogram parameters (RV, FVC), gradient decrease Р(а-et)CO2 in СРАР, RМ+СРАР groups in first 48 hours of postoperative period after large and giant ventral hernias plasty.Conclusions. Postoperative СРАР and its combination with intraoperative RМ improve the state of oxygenation, decrease the restrictive syndrome in the first 48 hours after large and giant hernias plasty

Severe infections in neutropenic patients.

Severe infections in neutropenic patients can rapidly progress to septic shock and multiorgan failure with a high associated mortality. In this article we discuss current practice, emerging trends and controversies, including the prophylactic and empiric use of antimicrobial therapy, and advances in cellular and immunotherapy. Neutropenia is no longer a consistent factor predicting poor outcome in haematological patients admitted to the ICU. Severe infections in neutropenic patients are often polymicrobial, and pathogen resistance remains a challenge. Invasive fungal infection is still predictive of poor outcome. There has been a rapid expansion in the diagnostics and treatment modalities available for patients with invasive fungal infection. Use of growth factors, polyvalent immunoglobulin, and cellular therapy appear to be of value in certain groups of patients. There is a move away from the use of noninvasive ventilation and the use of high-flow nasal oxygen therapy is one of a number of novel respiratory support strategies that is yet to be evaluated in this patient population. Translation of current advances in antimicrobial, cellular and immunotherapy, and diagnostics to aid clinical management by the bedside is important in reducing morbidity and mortality for neutropenic patients with severe infection.

Effect of Different Respiratory Modes on Return of Spontaneous Circulation in a Newborn Piglet Model of Hypoxic Cardiac Arrest

Background: There are no clear evidence-based recommendations on the use of different techniques of respiratory support and chest compressions (CC) during neonatal cardiopulmonary resuscitation (CPR). Objectives: To determine the effects of different respiratory support strategies along with CC representing clinical practice on the return of spontaneous circulation (ROSC) in hypoxic newborn piglets with cardiac arrest. We hypothesized that use of a T-piece resuscitator (TPR) providing positive end-expiratory pressure (PEEP) reduces time to ROSC as compared to a self-inflating bag (SIB) without PEEP. Furthermore, we explored the effects of a ventilator providing inflations without synchrony to CC. Methods: Thirty-three newborn piglets were exposed to hypoxia until asystole occurred and randomized into three groups and resuscitated according to ILCOR guidelines: group 1 = TPR [peak inspiratory pressure (PIP)/PEEP of 25/5 cm H₂O, rate 30/min], inflations interposed between CC (3:1 ratio); group 2 = SIB (PIP of 25 cm H₂O without PEEP, rate 30/min), inflations interposed between CC (3:1 ratio), and group 3 = ventilator (PIP/PEEP of 25/5 cm H₂O, rate 30/min), CC were applied with a rate of 120/min without synchrony to inflations. Animals were supported for 120 min after ROSC. Primary outcome was time to ROSC. Results: All animals achieved ROSC. We found no significant difference in time to ROSC between groups [median (IQR); TPR: 150 s (150-210); SIB: 150 s (120-180); ventilator: 180 s (150-345)]. There was no difference in use of epinephrine, in blood gases or hemodynamic parameters during the 120-min observation time after ROSC. Conclusions: We found no significant effect of different respiratory support strategies during CPR on ROSC.

Economic Impact of Changes in Neonatal Intensive Care Unit Ventilation Strategies with the Advent of New Noninvasive Ventilation Techniques: A Review and Proposed Assessment Framework for High Flow Therapy as a Routine Respiratory Support Paradigm.

Background: High flow therapy (HFT) has been demonstrated to be a safe and effective noninvasive respiratory support technique for the treatment of pre-term infants in neonatal intensive care. Objectives: Our objective was to develop a quantitative framework based on available evidence to estimate the economic impact of adoption of a HFT respiratory support strategy compared to current standard of care. Methods: Model parameters were derived from a recent study comparing respiratory modality utilization between five US-based neonatal intensive care units (NICUs) adopting a HFT strategy and a larger pool of NICUs in the Vermont-Oxford Network (VON), and from single center experience. We computed the total cost difference between the respiratory support strategies based on published cost data. Parameter uncertainty was tested in sensitivity analyses. Results: The constructed model projected expected cost savings of $2,317 for the HFT strategy for the base case. Results were sensitive to length of HFT use, length of CMV, cost of HFT, and length of nCPAP support. Conclusions: Adoption of a HFT strategy appears to be associated with meaningful savings in total NICU episode of care costs, primarily because of reductions in the time of conventional mechanical ventilation. Further research is warranted to substantiate these findings.

Different Techniques of Respiratory Support Do Not Significantly Affect Gas Exchange during Cardiopulmonary Resuscitation in a Newborn Piglet Model

Background: There are no evidence-based recommendations on the use of different techniques of respiratory support and chest compressions (CC) during neonatal cardiopulmonary resuscitation (CPR). Objectives: We studied the short-term effects of different ventilatory support strategies along with CC representing clinical practice on gas exchange [arterial oxygen saturation (SaO₂), arterial partial pressure of oxygen (PaO₂) and arterial partial pressure of carbon dioxide (PaCO₂)], hemodynamics and cerebral oxygenation. We hypothesized that in newborn piglets with cardiac arrest, use of a T-piece resuscitator (TPR) providing positive end-expiratory pressure (PEEP) improves gas exchange as measured by SaO₂ during CPR as compared to using a self-inflating bag (SIB) without PEEP. Furthermore, we explored the effects of a mechanical ventilator without synchrony to CC. Methods: Thirty newborn piglets with asystole were randomized into three groups and resuscitated for 20 min [fraction of inspired oxygen (FiO₂) = 0.21 for 10 min and 1.0 thereafter]. Group 1 received ventilation using a TPR [peak inspiratory pressure (PIP)/PEEP of 20/5 cm H₂O, rate 30/min] with inflations interposed between CC (3:1 ratio). Group 2 received ventilation using a SIB (PIP of 20 cm H₂O without PEEP, rate 30/min) with inflations interposed between CC (3:1 ratio). Group 3 received ventilation using a mechanical ventilator (PIP/PEEP of 20/5 cm H₂O, rate 30/min). CC were applied with a rate of 120/min without synchrony to inflations. Results: We found no significant differences in SaO₂ between the three groups. However, there was a trend toward a higher SaO₂ [TPR: 28.0% (22.3-40.0); SIB: 23.7% (13.4-52.3); ventilator: 44.1% (39.2-54.3); median (interquartile range)] and a lower PaCO₂ [TPR: 95.6 mm Hg (82.1-113.6); SIB: 100.8 mm Hg (83.0-108.0); ventilator: 74.1 mm Hg (68.5-83.1); median (interquartile range)] in the mechanical ventilator group. Conclusions: We found no significant effect on gas exchange using different respiratory support strategies during CPR.

Respiratory consequences of prematurity: evolution of a diagnosis and development of a comprehensive approach.

Bronchopulmonary dysplasia (BPD) is the most common respiratory consequence of premature birth and contributes to significant short- and long-term morbidity, mortality, and resource utilization. Initially defined as a radiographic, clinical, and histopathologic entity, the chronic lung disease known as BPD has evolved as obstetrical and neonatal care have improved the survival of lower gestational age infants. Now, definitions based on need for supplemental oxygen at 28 days and or 36 weeks provide a useful reference point in the NICU, but are no longer based on histopathologic findings, and are neither designed to predict longer-term respiratory consequences nor to study the evolution of a multifactorial disease. The aims of this review are to critically examine the evolution of the diagnosis of BPD and the challenges inherent to current classifications. We found that the increasing use of respiratory support strategies that administer ambient air without supplemental oxygen confounds oxygen-based definitions of BPD. Furthermore, lack of reproducible, genetic, biochemical, and physiologic biomarkers limits the ability to identify impending BPD for early intervention, quantify disease severity for standardized classification and approaches, and reliably predict the long-term outcomes. More comprehensive, multidisciplinary approaches to overcome these challenges involve longitudinal observation of extremely preterm infants, not only those with BPD, using genetic, environmental, physiologic and clinical data as well as large databases of patient samples. The Prematurity and Respiratory Outcomes Program (PROP) will provide such a framework to address these challenges through high-resolution characterization of both NICU and post-NICU discharge outcomes.

Respiratory support strategy of severe sepsis in children

The definition of severe sepsis has been renewed in 2012 international guidelines for management of severe sepsis and septic shock.This article summarizes briefly respiratory support strategy of severe sepsis which incorporated with new guideline and recent progress in sepsis and mechanical ventilation (MV). Oxygen therapy, indication of mechanical ventilation, the support roles of MV on septic shock, drug selection, MV strategy and hemodynamic monitoring are included in this article. Key words: Sepsis; Respiratory support; Mechanical ventilation; Child

Association between mechanical ventilation and neurodevelopmental disorders in a nationwide cohort of extremely low birth weight infants.

Mechanical ventilation for preterm infants independently contributes to poor neurodevelopmental performance. However, few studies have investigated the association between the duration of mechanical ventilation and the risk for various developmental disorders in extremely low birth weight (ELBW) (<1000g) infants. Using a large nationwide database, we did a 10-year retrospective follow-up study to explore the effect of mechanical ventilation on the incidence of cerebral palsy (CP), autism spectrum disorder (ASD), intellectual disability (ID), and attention-deficit/hyperactivity disorder (ADHD) in ELBW infants born between 1998 and 2001. Seven hundred twenty-eight ELBW infants without diagnoses of brain insults or focal brain lesions in the initial hospital stay were identified and divided into three groups (days on ventilator: ≦2, 3-14, ≧15 days). After adjusting for demographic and medical factors, the infants in the ≧15 days group had higher risks for CP (adjusted hazard ratio: 2.66; 95% confidence interval: 1.50-4.59; p<0.001) and ADHD (adjusted hazard ratio: 1.95; 95% confidence interval: 1.02-3.76; p<0.05), than did infants in the ≦2 days group. The risk for ASD or ID was not significantly different between the three groups. We conclude that mechanical ventilation for ≧15 days increased the risk for CP and ADHD in ELBW infants even without significant neonatal brain damage. Developing a brain-protective respiratory support strategy in response to real-time cerebral hemodynamic and oxygenation changes has the potential to improve neurodevelopmental outcomes in ELBW infants.

The role of non-invasive ventilation in blunt chest trauma: systematic review and meta-analysis.

Respiratory support is the mainstay for the management of patients with pulmonary contusion following blunt chest trauma. In patients not requiring immediate intubation and ventilation, the optimal respiratory management strategy is not clear. This systematic review and meta-analysis aimed to determine the efficacy of non-invasive ventilation (NIV), as compared to traditional respiratory support strategies (i.e., high-flow facemask oxygen or pre-emptive intubation and ventilation), in adult patients with blunt chest trauma. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing NIV to traditional forms of respiratory support (i.e., facemask oxygen or intubation and ventilation) in an adult trauma population. For each eligible trial, we extracted the outcomes of all-cause mortality, length of intensive care unit (ICU) stay, length of hospital stay, and pneumonia. We identified 643 citations, selected 17 for full-text evaluation, and identified three eligible RCTs. Patients receiving NIV had a non-significant reduction in the risk of death (OR 0.55; 95% CI 0.18-1.70; I (2)=0%), but significant reductions in length of ICU stay (mean difference -2.45days; 95% CI -4.27 to -0.63; I (2)=66%), length of hospital stay (mean difference -4.60days; 95% CI -8.81 to -0.39; I (2)=85%), and risk of pneumonia (OR 0.20; 95% CI 0.09-0.47; I (2)=0%). This meta-analysis suggests that NIV is superior to both high-flow facemask oxygen or pre-emptive intubation and ventilation in patients with blunt chest trauma who have no contraindication to NIV.

Is there a Difference in Surfactant Treatment of Respiratory Distress Syndrome in Premature Neonates? A Review

Exogenous surfactant treatment of premature infants with Respiratory Distress Syndrome (RDS) has been the standard of care for more than two decades. There are now many studies comparing various surfactant preparations. Data are clear that the synthetic surfactants without surfactant proteins are inferior to animal derived surfactant preparations. In the United States, commercially available surfactants are beractant, calfactant, poractant alfa, and lucinactant. Relative efficacy of the various available animal derived surfactants in the United States appear to favor poractant alfa, the surfactant preparation with the highest concentrations of phospholipids and high concentration of surfactant proteins, allowing a higher initial dose of phospholipids in preterm infants less than 32 weeks. A new synthetic surfactant with a surfactant protein analog, lucinactant, has been recently been approved for use in the United States. Synthetic surfactants hold the possibility of surfactant treatments without potential animal-born infectious agents or animal proteins that could induce an immune response in fragile premature infants with multiple medical problems. New surfactant administration strategies are described, complimenting new respiratory support strategies, designed to minimize invasive mechanical ventilation and decrease the frequency of chronic lung disease. Minimally invasive surfactant administration strategies are being developed to accommodate these new respiratory support strategies. The goal of this manuscript is to review the available surfactant preparations and their administration strategies.

Non-Invasive Ventilation and Surfactant Therapy

The lungs of premature infants are more vulnerable than term infants to the effects of invasive positive pressure ventilation. Published literature supporting the use of non-invasive respiratory support with CPAP, bi-level CPAP mode, such as, SiPAP and Nasal Intermittent Positive Pressure Ventilation (NIPPV), and surfactant administration strategies are discussed. This review focuses on non-invasive respiratory support strategies and selective early use of surfactant that may reduce the incidence of bronchopulmonary dysplasia.

Neonatal respiratory support strategies in the intensive care unit: an Italian survey

We carried out a survey of current practices of neonatal respiratory support in neonatal intensive care units (NICUs) in Italy with the aim of comparing the current reality with evidence from the literature. We sent a questionnaire by email to the 103 level III neonatal units in Italy. There was a 61 % (73/120) response rate to the questionnaire. We found that synchronized intermittent positive pressure ventilation is mostly used in infants in the acute phase of respiratory distress syndrome (RDS), while the majority of the units prefer volume-targeted ventilation for those in the weaning phase. Nasal continuous positive airway pressure is the most commonly used non-invasive mode of respiratory support, both in the acute and post-extubation phase of RDS. Surfactant is mainly given as rescue treatment. Infants receive caffeine before extubation and analgesia under mechanical ventilation, while post-natal steroids are given after the first week of life in the majority of the units. In conclusion, respiratory support strategies in Italian NICUs are frequently evidence-based. However, since there are areas where this does not occur, we suggest that focused interventions take place on these areas to help improve clinical practice and increase their adherence to evidence-based medical criteria.

Non‐invasive ventilation in critical care

Non-invasive ventilation refers to a number of respiratory support strategies commonly used in critical care settings. This paper describes the principles of non-invasive ventilation, the practicalities of its use and the evidence for its use in a number of common acute conditions.

Italian survey of neonatal respiratory support strategies

Although the management of respiratory distress syndrome (RDS) in preterm infants has been characterized by significant progress in recent years, it is difficult to translate the research results into clinical practice. Previous surveys have demonstrated that in some areas, the current management of RDS does not reflect evidence from randomized trials. Therefore, the Pulmonology Study Group of the Italian Society of Neonatology decided to perform a similar survey in Italy with the aim of identifying possible aspects of respiratory management of preterm infants with RDS that merit improvement, and of suggesting focused interventions for their resolution.

Respiratory support during the influenza A (H1N1) pandemic flu in Sweden

Acute respiratory insufficiency characterised critically ill patients during the influenza A (H1N1) pandemic 2009-2010. Detailed understanding of disease progression and outcome in relation to different respiratory support strategies is important. Data collected between August 2009 and February 2010 for a national intensive care unit influenza registry were combined with cases identified by the Swedish Institute for Infectious Disease Control. Clinical data was available for 95% (126/136) of the critically ill cases of influenza. Median age was 44 years, and major co-morbidities were present in 41%. Respiratory support strategies were studied among the 110 adult patients. Supplementary oxygen was sufficient in 15% (16), non-invasive ventilation (NIV) only was used in 20% (22), while transition from NIV to invasive ventilation (IV) was seen in 41% (45). IV was initiated directly in 24% (26). Patients initially treated with NIV had a higher arterial partial pressure of oxygen/fraction of oxygen in inspired gas ratio compared with those primarily treated with IV. Major baseline characteristics and 28-day mortality were similar, but 90-day mortality was higher in patients initially treated with NIV 17/67 (25%) as compared with patients primarily treated with IV 3/26 (12%), relative risk 1.2 (95% confidence interval 0.3-4.0). Critical illness because of 2009 influenza A (H1N1) in Sweden was dominated by hypoxic respiratory failure. The majority of patients in need of respiratory support were initially treated with NIV. In spite of less severe initial hypoxemia, initiation of ventilatory support with NIV was not associated with improved outcome.

Pulmonary Care and Adjunctive Therapies for Prevention and Amelioration of Bronchopulmonary Dysplasia

Shortly after the introduction of assisted ventilation in the newborn, bronchopulmonary dysplasia (BPD) was first described. Northway and coworkers described a group of preterm infants who developed chronic respiratory failure and characteristic radiographic changes after prolonged mechanical ventilation. The prevention and management of BPD in infants at risk is challenging due to the complex pathogenesis of multiple contributing factors that include prematurity, supplemental oxygen exposure, mechanical ventilation, patent ductus arterious, inflammation, genetic predisposition and postnatal infection. Treatment of existing BPD requires a coordinated approach including optimal nutrition, careful fluid management, evidence-based drug therapy, and gentle respiratory techniques aimed at minimizing lung injury. The best respiratory support strategy remains unclear and requires further investigation but includes avoidance of ventilator-induced lung injury (barotraumas and volutrauma), hyperoxemia, and hypocapnea. Among the available interventions antenatal steroids, caffeine, and surfactant have the best risk-benefit profile. Systemic postnatal corticosteroids should be used only in ventilated infants unable to be weaned from the ventilator. Quality improvement techniques may have a role towards improvement of hospital systems geared toward reduction of BPD.