Noninvasive mechanical ventilation

Predictors for prescription of noninvasive ventilation in the postoperative period of cardiac surgery: a systematic review

INTRODUCTION

The postoperative (PO) period after cardiac surgery is associated with the occurrence of respiratory complications. Noninvasive positive pressure ventilation (NIPPV) is largely used as a ventilatory support strategy after the interruption of invasive mechanical ventilation. However, the variables associated with NIPPV prescription are unclear.

OBJECTIVE

To describe the literature on predictors of NIPPV prescription in patients during the PO period of cardiac surgery.

MATERIALS AND METHODS

This systematic review was registered on the International Prospective Register of Systematic Reviews (PROSPERO) platform in December 2021 (CRD42021291973). Bibliographic searches were performed in February 2022 using the PubMed, Lilacs, Embase and PEDro databases, with no year or language restrictions. The Predictors for the prescription of NIPPV were considered among patients who achieved curative NIPPV.

RESULTS

A total of 349 articles were identified, of which four were deemed eligible and were included in this review. Three studies were retrospective studies, and one was a prospective safety pilot study. The total sample size in each study ranged from 109 to 1657 subjects, with a total of 3456 participants, of whom 283 realized NIPPV. Curative NIPPV was the only form of NIPPV in 75% of the studies, which presented this form of prescription in 5-9% of the total sample size, with men around 65 years old being the majority of the participants receiving curative NIPPV. The main indication for curative NIPPV was acute respiratory failure. Only one study realized prophylactic NIPPV (28% of 32 participants). The main predictors for the prescription of curative NIPPV in the PO period of cardiac surgery observed in this study were elevated body mass index (BMI), hypercapnia, PO lung injury, cardiogenic oedema and pneumonia.

CONCLUSIONS

BMI and lung alterations related to gas exchange disturbances are major predictors for NIPPV prescription in patients during the PO period of cardiac surgery. The identification of these predictors can benefit clinical decision-making regarding the prescription of NIPPV and help conserve human and material resources, thereby preventing the indiscriminate use of NIPPV.

Non-invasive ventilation restores the gut microbiota in rats with acute heart failure

Heart failure (HF) is an increasingly prevalent disease in humans; it induces multiple symptoms and damages health. The animal gut microbiota has critical roles in host health, which might be related to HF symptoms. Currently, several options are used to treat HF, including non-invasive ventilation (NIV). However, studies on gut microbiota responses to acute HF and associated treatments effects on gut communities in patients are scarce. Here, short-term (1 week after treatments) and long-term (3 months after treatment) variations in gut microbiota variations in rats with acute HF treated were examined NIV through high-throughput sequencing of the bacterial 16S rRNA gene. Through comparison of gut microbiota alpha diversity, it was observed lower gut microbiota richness and diversity in animals with acute HF than in normal animals. Additionally, beta-diversity analysis revealed significant alterations in the gut microbiota composition induced by acute HF, as reflected by increased Firmicutes/Bacteroidetes (F/B) ratios and Proteobacteria enrichment. When network analysis results were combined with the null model, decreased stability and elevated deterministic gut microbiota assemblies were observed in animals with acute HF. Importantly, in both short- and long-term periods, NIV was found to restore gut microbiota dysbiosis to normal states in acute HF rats. Finally, it was shown that considerable gut microbiota variations existed in rats with acute HF, that underlying microbiota mechanisms regulated these changes, and confirmed that NIV is suitable for HF treatment. In future studies, these findings should be validated with different model systems or clinical samples.

How to use noninvasive positive airway pressure device data reports to guide clinical care

There has been a significant increase in the past few decades in the number of children receiving noninvasive positive airway pressure (PAP) therapy at home. At present, PAP therapy can be successfully used in children of all ages, for a variety of indications. Data acquired from PAP devices is clinically useful, providing objective information regarding adherence, leak, and efficacy of PAP therapy. However, guidelines outlining a standardized approach to interpretation of PAP device data in pediatrics is currently lacking. Given the rapidly expanding use of PAP therapy in pediatric practice, we aim to provide an overview of the interpretation of data reports, otherwise called "data downloads," from PAP devices and illustrate how they can be used to guide clinical care.

Treatment of exacerbations of chronic obstructive pulmonary disease

AIM

To assess the quality of medical care provided in large Russian hospitals to patients with COPD exacerbation.

MATERIALS AND METHODS

The study included patients with acute exacerbations of COPD hospitalized into three large clinical hospitals in Moscow. The diagnosis of "COPD exacerbation" was established in accordance with current clinical recommendations. We collected the data about patients' demography, clinical signs and symptoms, blood gas analysis, chest radiography, drug therapy, oxygen therapy and respiratory support. The follow-up period was 90 days. The obtained data were compared with the data of patients from the multicenter study "European COPD Audit".

RESULTS

The leading clinical symptoms in COPD exacerbation were dyspnea (95.4%) and sputum production (60.7%). The majority of patients with COPD received short-acting β2-agonists (77.4%), systemic steroids (85.1%), antibiotics (79.0%) and theophyllines (48.1%). Noninvasive ventilation was performed in 8.6% of patients, oxygen therapy - in 23,8% of patients, pulmonary rehabilitation - in only 6,2% of patients. Chest radiography was performed in 97.9% of patients, pulmonary function tests - in 79.8%, blood gases analysis - in 19.3% of patients. The mean duration of hospitalization was 18.2±3.9 days, repeated hospitalization within 90 days occurs in 36.2% of patients. In-hospital mortality was 3.3%.

CONCLUSION

Based on the results of the study practical recommendations for improving the quality of medical care in acute exacerbations of COPD are proposed.

A pilot study of improvised CPAP (iCPAP) via face mask for the treatment of adult respiratory distress in low-resource settings

BACKGROUND

Continuous positive airway pressure (CPAP) is a mode of non-invasive ventilation used to treat a variety of respiratory conditions in the emergency department and intensive care unit. In low-resource settings where ventilators are not available, the ability to improvise a CPAP system from locally available equipment would provide a previously unavailable means of respiratory support for patients in respiratory distress. This manuscript details the design of such a system and its performance in healthy volunteers.

METHODS

An improvised CPAP system was assembled from standard emergency department equipment and tested in 10 healthy volunteers (6 male, 4 female; ages 29-33). The system utilizes a water seal and high-flow air to create airway pressure; it was set to provide a pressure of 5 cmH2O for the purposes of this pilot study. Subjects used the system in a monitored setting for 30 min. Airway pressure, heart rate, oxygen saturation, and end-tidal CO2 were monitored. Comfort with the device was assessed via questionnaire.

RESULTS

The system maintained positive airway pressure for the full trial period in all subjects, with a mean expiratory pressure (EP) of 5.1 cmH2O (SD 0.7) and mean inspiratory pressure (IP) of 3.2 cmH2O (SD 0.8). There was a small decrease in average EP (5.28 vs 4.88 cmH2O, p = 0.03) and a trend toward decreasing IP (3.26 vs 3.07 cmH2O, p = 0.22) during the trial. No significant change in heart rate, O2 saturation, respiratory rate, or end-tidal CO2 was observed. The system was well tolerated, ranked an average of 4.0 on a 1-5 scale for comfort (with 5 = very comfortable).

CONCLUSIONS

This improvised CPAP system maintained positive airway pressure for 30 min in healthy volunteers. Use did not cause tachycardia, hypoxia, or hypoventilation and was well tolerated. This system may be a useful adjunctive treatment for respiratory distress in low-resource settings. Further research should test this system in settings where other positive pressure modalities are not available.

Acute respiratory failure after drowning: a retrospective multicenter survey

OBJECTIVES

Despite the extensive literature on drowning, clinical data are still lacking on the best medical strategy to use. Acute respiratory failure (ARF) is the main component of drowning pathophysiology. The objectives of this multicenter study were to analyze the clinical course of drowning-related ARF patients and to describe the efficacy of the ventilatory strategies used.

METHODS

Medical records of drowned adult patients admitted in seven ICUs after prehospital emergency medical care during three consecutive summer periods were retrospectively analyzed.

RESULTS

Among the 126 patients (58±21 years) admitted, 38 patients with cardiac arrest at the scene were not analyzed, 26 received mechanical ventilation (MV), and 48 patients received noninvasive ventilation (NIV). Compared with patients placed under MV, the NIV patients presented a better initial neurological (Glasgow Coma Scale of 7±4 vs. 12±3, P<0.05) and hemodynamic status from the prehospital stage (mean arterial pressure of 77±18 vs. 96±18, P<0.001). With comparable ARF-related hypoxemia to MV, the NIV was maintained with success in 92% (44/48). Both MV and NIV were associated with rapid improvement of oxygenation and short ICU length of stay [3 (1-14) and 2 (1-7), respectively].

CONCLUSION

Despite the absence of recommendation for NIV use in case of drowning-related ARF, this technique was often used with safety and efficacy. The decision for NIV use was mainly based on the preserved or improved neurological status.

Non-Invasive Mechanical Ventilation in Critically Ill Trauma Patients: A Systematic Review

There is limited literature on non-invasive mechanical ventilation (NIMV) in patients with polytrauma-related acute respiratory failure (ARF). Despite an increasing worldwide application, there is still scarce evidence of significant NIMV benefits in this specific setting, and no clear recommendations are provided. We performed a systematic review, and a search of clinical databases including MEDLINE and EMBASE was conducted from the beginning of 1990 until today. Although the benefits in reducing the intubation rate, morbidity and mortality are unclear, NIMV may be useful and does not appear to be associated with harm when applied in properly selected patients with moderate ARF at an earlier stage of injury by experienced teams and in appropriate settings under strict monitoring. In the presence of these criteria, NIMV is worth attempting, but only if endotracheal intubation is promptly available because non-responders to NIMV are burdened by an increased mortality when intubation is delayed.

NIV by an interdisciplinary respiratory care team in severe respiratory failure in the emergency department limited to day time hours

Non-invasive ventilatory support is frequently used in patients with severe respiratory failure (SRF), but is often limited to intensive care units (ICU). We hypothesized that an instantaneous short course of NIV (up to 2 h), limited to regular working hours as an additional therapy on the emergency department (ED) would be feasible and could improve patient´s dyspnoea measured by respiratory rate and Borg visual dyspnea scale. NIV was set up by an interdisciplinary respiratory care team. Outside these predefined hours NIV was performed in the ICU. This is an observational cohort study over 1 year in the ED in a non-university hospital. Fifty-one % of medical emergencies arrived during regular working hours (5475 of 10,718 patients). In total, 63 patients were treated with instantaneous NIV. Door to NIV in the ED was 56 (31-97) min, door to ICU outside regular working hours was 84 (57-166) min. Within 1 h of NIV, the respiratory rate decreased from 30/min (25-35) to 19/min (14-24, p < 0.001), the Borg dyspnoea scale improved from 7 (5-8) to 2 (0-3, p < 0.001). In hypercapnic patients, the blood-pH increased from 7.29 (7.24-7.33) to 7.35 (7.29-7.40) and the pCO₂ dropped from 8.82 (8.13-10.15) to 7.45 (6.60-8.75) kPa. In patients with SRF of varying origin, instantaneous NIV in the ED during regular working hours was feasible in a non-university hospital setting, and rapidly and significantly alleviated dyspnoea and reduced respiratory rate. This approach proved to be useful as a bridge to the ICU as well as an efficient palliative dyspnoea treatment.

The efficacy of initial ventilation strategy for adult immunocompromised patients with severe acute hypoxemic respiratory failure: study protocol for a multicentre randomized controlled trial (VENIM)

Background

Acute respiratory failure (ARF) is still one of the most severe complications in immunocompromised patients. Our previous systematic review showed noninvasive mechanical ventilation (NIV) reduced mortality, length of hospitalization and ICU stay in AIDS/hematological malignancy patients with relatively less severe ARF, compared to invasive mechanical ventilation (IMV). However, this systematic review was based on 13 observational studies and the quality of evidence was low to moderate. The efficacy of NIV in more severe ARF and in patients with other causes of immunodeficiency is still unclear. We aim to determine the efficacy of the initial ventilation strategy in managing ARF in immunocompromised patients stratified by different disease severity and causes of immunodeficiency, and explore predictors for failure of NIV.

Methods and analysis

The VENIM is a multicentre randomized controlled trial (RCT) comparing the effects of NIV compared with IMV in adult immunocompromised patients with severe hypoxemic ARF. Patients who meet the indications for both forms of ventilatory support will be included. Primary outcome will be 30-day all-cause mortality. Secondary outcomes will include in-hospital mortality, length of stay in hospital, improvement of oxygenation, nosocomial infections, seven-day organ failure, adverse events of intervention, et al. Subgroups with different disease severity and causes of immunodeficiency will also be analyzed.

Discussion

VENIM is the first randomized controlled trial aiming at assessing the efficacy of initial ventilation strategy in treating moderate and severe acute respiratory failure in immunocompromised patients. The result of this RCT may help doctors with their ventilation decisions.

Trial registration

ClinicalTrials.gov NCT02983851. Registered 2 September 2016.

Management of acute respiratory diseases in the pediatric population: the role of oral corticosteroids

Respiratory diseases account for about 25% of all pediatric consultations, and 10% of these are for asthma. The other main pediatric respiratory diseases, in terms of incidence, are bronchiolitis, acute bronchitis and respiratory infections. Oral corticosteroids, in particular prednisolone, are often used to treat acute respiratory diseases given their anti-inflammatory effects. However, the efficacy of treatment with oral corticosteroids differs among the various types of pediatric respiratory diseases. Notably, also the adverse effects of corticosteroid treatment can differ depending on dosage, duration of treatment and type of corticosteroid administered — a case in point being growth retardation in long-course treatment. A large body of data has accumulated on this topic. In this article, we have reviewed the data and guidelines related to the role of oral corticosteroids in the treatment and management of pediatric bronchiolitis, wheezing, asthma and croup in the attempt to provide guidance for physicians. Also included is a section on the management of acute respiratory failure in children.

Non-invasive positive pressure ventilation for acute asthma in children

BACKGROUND

Asthma is one of the most common reasons for hospital admission among children and constitutes a significant economic burden. Use of non-invasive positive pressure ventilation (NPPV) in the care of children with acute asthma has increased even though evidence supporting the intervention has been considered weak and clinical guidelines do not recommend the intervention. NPPV might be an effective intervention for acute asthma, but no systematic review has been conducted to assess the effects of NPPV as an add-on therapy to usual care in children with acute asthma.

OBJECTIVES

To assess the benefits and harms of NPPV as an add-on therapy to usual care (e.g. bronchodilators and corticosteroids) in children with acute asthma.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register (CAGR). The Register contains trial reports identified through systematic searches of bibliographic databases, including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, AMED and PsycINFO, and by handsearching of respiratory journals and meeting abstracts. We also conducted a search of ClinicalTrials.gov (www.ClinicalTrials.gov) and the WHO trials portal (www.who.int/ictrp/en/). We searched all databases from their inception to February 2016, with no restriction on language of publication.

SELECTION CRITERIA

We included randomised clinical trials (RCTs) assessing NPPV as add-on therapy to usual care versus usual care for children (age < 18 years) hospitalised for an acute asthma attack.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts. We retrieved all relevant full-text study reports, independently screened the full text, identified trials for inclusion and identified and recorded reasons for exclusion of ineligible trials. We resolved disagreements through discussion or, if required, consulted a third review author. We recorded the selection process in sufficient detail to complete a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) flow diagram and 'Characteristics of excluded studies' table. We identified the risk of bias of included studies to reduce the risk of systematic error. We contacted relevant study authors when data were missing.

MAIN RESULTS

We included two RCTs that randomised 20 participants to NPPV and 20 participants to control. We assessed both studies as having high risk of bias; both trials assessed effects of bilateral positive airway pressure (BiPAP). Neither trial used continuous positive airway pressure (CPAP). Controls received standard care. Investigators reported no deaths and no serious adverse events (Grades of Recommendation, Assessment, Development and Evaluation (GRADE): very low quality of evidence due to serious risk of bias and serious imprecision of results). Both trials showed a statistically significant reduction in symptom score. One trial did not report a standard deviation (SD), but by using an estimated SD, we found a statistically significantly reduced asthma symptom score (mean difference (MD) -2.50, 95% confidence interval (CI) -4.70 to -0.30, P = 0.03, 19 participants, GRADE: very low quality of evidence). In the other trial, NPPV was associated with a lower total symptom score (5.6 vs 1.9, 16 participants, very low quality of evidence) before cross-over, but investigators did not report an SD, nor could it be estimated from the first phase of the trial, before the cross-over. These gains could be clinically relevant, as a reduction of three or more points in symptom score is considered a clinically meaningful change. Researchers documented five dropouts (12.5%), four of which were due to intolerance to NPPV, and one to respiratory failure requiring intubation. Owing to insufficient reporting in the latter trial and use of different scoring systems, it was not possible to conduct a meta-analysis nor a Trial Sequential Analysis.

AUTHORS' CONCLUSIONS

Current evidence does not permit confirmation or rejection of the effects of NPPV for acute asthma in children. Large RCTs with low risk of bias are warranted.

Noninvasive versus invasive mechanical ventilation for immunocompromised patients with acute respiratory failure: a systematic review and meta-analysis

Background

To determine the effects of noninvasive mechanical ventilation (NIV) compared with invasive mechanical ventilation (IMV) as the initial mechanical ventilation on clinical outcomes when used for treatment of acute respiratory failure (ARF) in immunocompromised patients.

Methods

We searched PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), the Chinese Biomedical Literature Database (CBM) and other databases. Subgroup analyses by disease severity and causes of immunodeficiency were also conducted.

Results

Thirteen observational studies with a total of 2552 patients were included. Compared to IMV, NIV was shown to significantly reduce in-hospital mortality (OR 0.43, 95 % CI 0.23 to 0.80, P value = 0.007) and 30-day mortality (OR 0.34, 95 % CI 0.20 to 0.61, P value < 0.0001) in overall analysis. Subgroup analysis showed NIV had great advantage over IMV for less severe, AIDS, BMT and hematological malignancies patients in reducing mortality and duration of ICU stay.

Conclusions

The overall evidence we obtained shows NIV does more benefits or at least no harm to ARF patients with certain causes of immunodeficiency or who are less severe.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0289-y) contains supplementary material, which is available to authorized users.

Domiciliary noninvasive positive airway pressure therapy in children

There has been a dramatic increase in the past few decades in the number of children receiving noninvasive positive airway pressure (PAP) therapy at home. Although PAP therapy was first prescribed for children with obstructive sleep apnea, the indications have rapidly widened to include treatment for central hypoventilation syndromes, neuromuscular and chest wall disorders as well as primary respiratory diseases. Given the rapidly expanding use of PAP therapy in children, pediatric pulmonologists need to be familiar with the indications, technical and safety considerations as well as potential complications and challenges that may arise when caring for children using PAP therapy. This review article covers the definition of PAP therapy, modes, interfaces, devices, indications, contraindications, suggested settings, complications as well as the factors influencing the adherence.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Acute Respiratory Failure

Acute respiratory failure accounts for 25–40 % of ICU admissions and carries a mortality rate of 30 % or more. In this chapter, we classify acute respiratory failure in two main types, based on their primary physiologic abnormality:

Disorders of the airways, where increase of airway resistance to gas flow determines pharmacologic treatment and ventilatory strategies. These disorders are mainly asthma and chronic obstructive pulmonary disease.

Disorders of the alveoli, where a decrease of lung compliance mandates the use of higher ventilatory pressures that can recruit but also damage the lung. These disorders include the acute respiratory distress syndrome, pneumonia, acute cardiogenic pulmonary edema, and influenza.

Additional types of acute respiratory failure are described elsewhere in this book: disorders that result from neuromuscular disease in Chap. 10.1007/978-3-319-19668-8_19 and pulmonary disorders of the circulation, including pulmonary thromboembolism, in Chap. 10.1007/978-3-319-19668-8_27. Finally, we provide a section on weaning from mechanical ventilation, which includes the pathophysiology of the ventilatory load imposed by the prolonged acute respiratory failure, the possible ways to support the weakened respiratory system, and the current process of screening and testing for readiness to remove the ventilator.

Home Mechanical Ventilation in Children

The number of children dependent on home mechanical ventilation has been reported to be increasing in many countries around the world. Home mechanical ventilation has been well accepted as a standard treatment of children with chronic respiratory failure. Some children may need mechanical ventilation as a lifelong therapy. To send mechanically ventilated children back home may be more difficult than adults. However, relatively better outcomes have been demonstrated in children. Children could be safely ventilated at home if they are selected and managed properly. Conditions requiring home ventilation include increased respiratory load from airway or lung pathologies, ventilatory muscle weakness and failure of neurologic control of ventilation. Home mechanical ventilation should be considered when the patient develops progressive respiratory failure or intractable failure to wean mechanical ventilation. Polysomnography or overnight pulse oximetry plus capnometry are used to detect nocturnal hypoventilation in early stage of respiratory failure. Ventilator strategy including non-invasive and invasive approach should be individualized for each patient. The author strongly believes that parents and family members are able to take care of their child at home if they are trained and educated effectively. A good team work with dedicated members is the key factor of success.

Noninvasive Mechanical Ventilation in Acute Respiratory Failure Patients: A Respiratory Therapist Perspective

Physiotherapist in Chile and Respiratory Therapist worldwide are the professionals who are experts in respiratory care, in mechanical ventilation (MV), pathophysiology and connection and disconnection criteria. They should be experts in every aspect of the acute respiratory failure and its management, they and are the ones who in medical units are able to resolve doubts about ventilation and the setting of the ventilator. Noninvasive mechanical ventilation should be the first-line of treatment in acute respiratory failure, and the standard of care in severe exacerbations of chronic obstructive pulmonary disease, acute cardiogenic pulmonary edema, and in immunosuppressed patients with high levels of evidence that support the work of physiotherapist. Exist other considerations where most of the time, physicians and other professionals in the critical units do not take into account when checking the patient ventilator synchrony, such as the appropriate patient selection, ventilator selection, mask selection, mode selection, and the selection of a trained team in NIMV. The physiotherapist needs to evaluate bedside; if patients are properly connected to the ventilator and in a synchronously manner. In Chile, since 2004, the physioterapist are included in the guidelines as a professional resource in the ICU organization, with the same skills and obligations as those described in the literature for respiratory therapists.

Elevated Extravascular Lung Water Index (ELWI) as a Predictor of Failure of Continuous Positive Airway Pressure Via Helmet (Helmet-CPAP) in Patients With Acute Respiratory Failure After Major Surgery

INTRODUCTION

NIV is increasingly used for prevention and treatment of respiratory complications and failure. Some of them are admitted to the PACU with advanced hemodynamic monitors which allow quantification of Extravascular Lung Water (EVLW) by transpulmonary thermodilution technique (TPTD) and Pulmonary Vascular Permeability (PVP) providing information on lung edema.

AIM

The objective of this study was to ascertain if EVLW Index and PVP Index may predict failure (intubation) or success (non-intubation) in patients developing acute respiratory failure (ARF) in the postoperative period following major abdominal surgery, where the first line of treatment was non-invasive continuous positive airway pressure via a helmet.

METHODS

Hemodynamic variables, EVLWI and PVPI were monitored with a transpulmonary thermodilution hemodynamic monitor device (PiCCO™) before and after the application of CPAP.

RESULTS

Avoidance of intubation was observed in 66% of patients with Helmet-CPAP. In these patients after the first hour of application of CPAP, PaO2/FiO2 ratio significantly increased (303.33±65.2 vs. 141.6±14.6, P<.01). Before starting Helmet-CPAP values of EVLWI and PVPI were significantly lower in non-intubated patients (EVLWI 8.6±1.08 vs. 11.8±0.99ml/kg IBW, P<.01 and PVPI 1.7±0.56 vs. 3.0±0.88, P<.01). An optimal cut-off value for EVLWI was established at 9.5, and at 2.45 for PVPI (sensitivity of 0.7; specificity of 0.9, P<.01).

CONCLUSION

In this type of patient the physiological parameters that predict the failure of Helmet-CPAP with the greatest accuracy were the value of the EVLWI and PVPI before Helmet-CPAP institution and the PaO2/FiO2 ratio and the respiratory rate after one hour of CPAP.

Arterial pulse pressure variation suitability in critical care: A French national survey

OBJECTIVE

Arterial pulse pressure variation (PPV) has been used as an accurate index to predict fluid responsiveness. However, many confounding factors have been recently described. The aims of this study were to assess the conditions of applicability of PPV in intensive care units (ICU).

STUDY DESIGN

A one-day French national survey.

PATIENTS AND METHODS

A form assessing the suitability of PPV was completed by practitioners for each critically-ill patient included on a set day.

RESULTS

Four hundred and sixty-five patients were included in 36 ICUs. A regular sinus rhythm was noted in 408 (88%) patients and the presence of an arterial line in 324 (70%) patients. One hundred and twenty-seven (27%) patients were mechanically ventilated without spontaneous breathing. Only six patients (1.3%) had no confounding factors modifying the threshold value of the PPV.

CONCLUSION

The incidence of ICU patients in whom PPV was suitable and without confounding factors were respectively 18% and 1.3% in this one-day French national survey.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Utilization of mechanical ventilation for asthma exacerbations: analysis of a national database

BACKGROUND

The current frequency of noninvasive (NIV) and invasive mechanical ventilation use in asthma exacerbations (AEs) and the relationship to outcomes are unknown.

METHODS

We used the Healthcare Cost and Utilization Project Nationwide Inpatient Sample to identify patients discharged with a principal diagnosis of AE. For each discharge, we determined whether NIV or invasive mechanical ventilation was initiated during the first 2 hospital days. Using multivariate logistic regression to adjust for potential confounders, we determined whether use of mechanical ventilation and in-hospital mortality changed between 2000 and 2008.

RESULTS

The number of AEs increased by 15.8% from 2000 to 2008. The proportion of admissions for which invasive mechanical ventilation was used during the first 2 days decreased from 1.4% in 2000 to 0.73% in 2008, whereas NIV use increased from 0.34% to 1.9%. The adjusted mortality from AEs requiring NIV or invasive mechanical ventilation was unchanged from 2000 to 2008. The hospital stay was also unchanged.

CONCLUSIONS

There was a substantial increase in the use of mechanical ventilation, accompanied by a shift from invasive mechanical ventilation to NIV. Although we could not determine the clinical reasons for this increase, hospital stay and mortality were unchanged. A randomized trial is needed to determine whether NIV can improve outcomes in AEs before widespread adoption makes it impossible to conduct such a trial.

Noninvasive ventilation and the upper airway: should we pay more attention?

In an effort to reduce the complications related to invasive ventilation, the use of noninvasive ventilation (NIV) has increased over the last years in patients with acute respiratory failure. However, failure rates for NIV remain high in specific patient categories. Several studies have identified factors that contribute to NIV failure, including low experience of the medical team and patient–ventilator asynchrony. An important difference between invasive ventilation and NIV is the role of the upper airway. During invasive ventilation the endotracheal tube bypasses the upper airway, but during NIV upper airway patency may play a role in the successful application of NIV. In response to positive pressure, upper airway patency may decrease and therefore impair minute ventilation. This paper aims to discuss the effect of positive pressure ventilation on upper airway patency and its possible clinical implications, and to stimulate research in this field.

Non-invasive positive pressure ventilation in children

Non-invasive positive pressure ventilation is increasingly used in children both in acute and in chronic setting. Clinical data supporting safety, efficacy and limitations in children are growing. Technical problems related to the ventilators performance and interfaces selection have not been fully resolved, especially for younger children. Non-invasive ventilation can be applied at home. Its use at home requires appropriate diagnostic procedures, accurate titration of the ventilators, cooperative and educated families and careful, well-organized follow-up programs.

Evolution of the use of noninvasive mechanical ventilation in chronic obstructive pulmonary disease in a Spanish region, 1997-2010

INTRODUCTION

Noninvasive mechanical ventilation (NIV) appeared in the 1980s as an alternative to invasive mechanical ventilation (IMV) in patients with acute respiratory failure. We evaluated the introduction of NIV and the results in patients with acute exacerbation of chronic obstructive pulmonary disease in the Region of Murcia (Spain).

SUBJECTS AND METHODS

A retrospective observational study based on the minimum basic hospital discharge data of all patients hospitalised for this pathology in all public hospitals in the region between 1997 and 2010. We performed a time trend analysis on hospital attendance, the use of each ventilatory intervention and hospital mortality through joinpoint regression.

RESULTS

We identified 30.027 hospital discharges. Joinpoint analysis: downward trend in attendance (annual percentage change [APC]=-3.4, 95% CI: - 4.8; -2.0, P <.05) and in the group without ventilatory intervention (APC=-4.2%, -5.6; -2.8, P <.05); upward trend in the use of NIV (APC=16.4, 12.0; 20. 9, P <.05), and downward trend that was not statistically significant in IMV (APC=-4.5%, -10.3; 1.7). We observed an upward trend without statistical significance in overall mortality (APC=0.5, -1.3; 2.4) and in the group without intervention (APC=0.1, -1.6; 1.9); downward trend with statistical significance in the NIV group (APC=-7.1, -11.7; -2.2, P <.05) and not statistically significant in the IMV group (APC=-0,8, -6, 1; 4.8). The mean stay did not change substantially.

CONCLUSIONS

The introduction of NIV has reduced the group of patients not receiving assisted ventilation. No improvement in results was found in terms of mortality or length of stay.

Understanding advanced modes of mechanical ventilation

Approaches to mechanical ventilation (MV) are consistently changing and the level of ventilator sophistication provides opportunities to improve pulmonary support for critically ill patients. Advanced MV modes are used in the treatment of patients with complex pulmonary conditions. To achieve optimal patient outcomes MV modes that best meet the needs of patient's evolving pulmonary conditions are necessary. It's essential for nurses to integrate pulmonary MV knowledge in the care of critically ill patients. The purpose of this article is to describe the evidence supporting lung protective modes of MV used in the care of critically ill adults.