Does noninvasive ventilation reduce the ICU nosocomial infection risk? A prospective clinical survey

SAPS2, APACHE2, SOFA, and Core-10-TISS upon admission as risk indicators for ICU-acquired infections: a retrospective cohort study

PURPOSE

Early identification of high-risk patients is an important component in improving infection prevention. The SAPS2, APACHE2, Core-10-TISS, and SOFA scores are already widely used to estimate mortality, morbidity and nursing workload, but this study evaluated their usefulness in assessing a patient's risk of ICU-acquired infection.

METHODS

We conducted a retrospective cohort study by analyzing all patient admissions to seven ICUs at Charité Berlin, Germany in 2017 and 2018. The four scores were documented by physicians on the day of admission. The infection control staff monitored daily whether the patients experienced lower respiratory tract infections (LRTIs), urinary tract infections (UTIs), or primary blood stream infections (PBSIs). For each combination of scoring system and infection type, an adjusted Fine and Gray model was fitted.

RESULTS

We analyzed 5053 ICU admissions and observed at least one ICU-acquired infection in N = 253 patients (incidence density: 4.73 per 1000 days). 59.0% (N = 2983) of the patients were male, median age was 66 years (IQR 55-77) and median length of stay was 6 days (IQR 4-12). All models showed that patients with a higher score value were at higher risk for ICU-acquired first PBSI, LRTI, or UTI, except for the model of APACHE2 and PBSI. Patients with a SAPS2 score of > 50 points showed an increased risk of infection of sHR = 2.34 for PBSIs (CI 1.06-5.17, p < 0.05), sHR = 2.33 for LRTIs (1.53-2.55, p < 0.001) and sHR = 2.25 for UTIs (1.23-4.13, p < 0.01) when compared to the reference group with 0-30 points.

CONCLUSIONS

The result of this study showed that admission scores of SAPS2, Core-10-TISS, APACHE2, and SOFA might be adequate indicators for assessing a patient's risk of ICU-acquired infection.

Comparison of Local and Systemic Inflammation During Invasive Versus Noninvasive Ventilation in Rats

The impact of noninvasive ventilation (NIV) on local and systemic inflammation is poorly characterized, particularly when compared with invasive mechanical ventilation (IMV). We sought to quantify the local and systemic inflammatory response of these 2 respiratory treatments in rats with lipopolysaccharide (LPS)-induced lung injury (LPS-injured) and healthy rats. Animals were subjected to 4 h of NIV or IMV treatments at noninjurious settings, or 4 h of control treatment in which healthy or LPS-injured animals remained spontaneously breathing under isoflurane anesthesia with no respiratory support. Cytokines were then quantified in the serum and lung tissue by multiplex enzyme-linked immunosorbent assay. Contrary to our hypothesis, there were no significant differences in cytokine levels in serum or lung when comparing the NIV- and IMV-treated groups; this was true in both LPS-injured and healthy rats. However, within the LPS-injured group, pulmonary levels of interleukin (IL)-1α, IL-6, and tumor necrosis factor α were significantly lower in the NIV-treated group than in control but not in the IMV-treated group compared with control. We conclude that NIV, unlike IMV, could attenuate local inflammation.

Protocol-driven early tracheal extubation in patients with flaccid neuromuscular scoliosis and pre-existing lung disease

PURPOSE

To review the results of a postoperative respiratory pathway for patients with muscular dystrophy (MD) and spinal muscular atrophy (SMA) undergoing spinal surgery.

METHODS

With IRB approval, a retrospective review was done on all patients with SMA and MD undergoing spinal surgery on a neuromuscular protocol. Baseline demographics, perioperative results, and long-term outcomes were collected. Per the protocol, patients remained intubated after surgery and were transported to the intensive care unit (ICU) for extubation. We present the results of protocol implementation and compare patients with MD to those with SMA.

RESULTS

Twenty-four patients were treated using the protocol. Average age was 13.1 years. Severe restrictive lung disease was present in 75% of patients. Nocturnal BiPAP was required in 68% of patients. Average number of instrumented levels was 17. All patients were immediately extubated upon entering the ICU. There were three respiratory complications and only was patient was re-intubated. Average ICU stay was 1.8 days and average hospital length of stay was 6.7 days. No differences in postoperative inspiratory or expiratory positive airway pressures were observed between the MD and SMA groups.

CONCLUSION

Through a multidisciplinary neuromuscular protocol, excellent clinical outcomes were achieved in patients with neuromuscular scoliosis and restrictive lung disease, with complication rates and length of stay significantly lower than previously published data.

LEVEL OF EVIDENCE

IV.

Reduced Air Leakage During Non-Invasive Ventilation Using a Simple Anesthetic Mask With 3D-Printed Adaptor in an Anthropometric Based Pediatric Head-Lung Model

Non-invasive ventilation (NIV) is increasingly used in the support of acute respiratory failure in critically ill children admitted to the pediatric intensive care unit (PICU). One of the major challenges in pediatric NIV is finding an optimal fitting mask that limits air leakage, in particular for young children and those with specific facial features. Here, we describe the development of a pediatric head-lung model, based on 3D anthropometric data, to simulate pediatric NIV in a 1-year-old child, which can serve as a tool to investigate the effectiveness of NIV masks. Using this model, the primary aim of this study was to determine the extent of air leakage during NIV with our recently described simple anesthetic mask with a 3D-printed quick-release adaptor, as compared with a commercially available pediatric NIV mask. The simple anesthetic mask provided a better seal resulting in lower air leakage at various positive pressure levels as compared with the commercial mask. These data further support the use of the simple anesthetic mask as a reasonable alternative during pediatric NIV in the acute setting. Moreover, the pediatric head-lung model provides a promising tool to study the applicability and effectiveness of customized pediatric NIV masks in the future.

A scoring system derived from electronic health records to identify patients at high risk for noninvasive ventilation failure

OBJECTIVE

To develop and validate a clinical risk prediction score for noninvasive ventilation (NIV) failure defined as intubation after a trial of NIV in non-surgical patients.

DESIGN

Retrospective cohort study of a multihospital electronic health record database.

PATIENTS

Non-surgical adult patients receiving NIV as the first method of ventilation within two days of hospitalization.

MEASUREMENT

Primary outcome was intubation after a trial of NIV. We used a non-random split of the cohort based on year of admission for model development and validation. We included subjects admitted in years 2010-2014 to develop a risk prediction model and built a parsimonious risk scoring model using multivariable logistic regression. We validated the model in the cohort of subjects hospitalized in 2015 and 2016.

MAIN RESULTS

Of all the 47,749 patients started on NIV, 11.7% were intubated. Compared with NIV success, those who were intubated had worse mortality (25.2% vs. 8.9%). Strongest independent predictors for intubation were organ failure, principal diagnosis group (substance abuse/psychosis, neurological conditions, pneumonia, and sepsis), use of invasive ventilation in the prior year, low body mass index, and tachypnea. The c-statistic was 0.81, 0.80 and 0.81 respectively, in the derivation, validation and full cohorts. We constructed three risk categories of the scoring system built on the full cohort; the median and interquartile range of risk of intubation was: 2.3% [1.9%-2.8%] for low risk group; 9.3% [6.3%-13.5%] for intermediate risk category; and 35.7% [31.0%-45.8%] for high risk category.

CONCLUSIONS

In patients started on NIV, we found that in addition to factors known to be associated with intubation, neurological, substance abuse, or psychiatric diagnoses were highly predictive for intubation. The prognostic score that we have developed may provide quantitative guidance for decision-making in patients who are started on NIV.

High-Flow, Noninvasive Ventilation and Awake (Nonintubation) Proning in Patients With Coronavirus Disease 2019 With Respiratory Failure

The coronavirus disease 2019 pandemic will be remembered for the rapidity with which it spread, the morbidity and mortality associated with it, and the paucity of evidence-based management guidelines. One of the major concerns of hospitals was to limit spread of infection to health-care workers. Because the virus is spread mainly by respiratory droplets and aerosolized particles, procedures that may potentially disperse viral particles, the so-called "aerosol-generating procedures" were avoided whenever possible. Included in this category were noninvasive ventilation (NIV), high-flow nasal cannula (HFNC), and awake (nonintubated) proning. Accordingly, at many health-care facilities, patients who had increasing oxygen requirements were emergently intubated and mechanically ventilated to avoid exposure to aerosol-generating procedures. With experience, physicians realized that mortality of invasively ventilated patients was high and it was not easy to extubate many of these patients. This raised the concern that HFNC and NIV were being underutilized to avoid intubation and to facilitate extubation. In this article, we attempt to separate fact from fiction and perception from reality pertaining to the aerosol dispersion with NIV, HFNC, and awake proning. We describe precautions that hospitals and health-care providers must take to mitigate risks with these devices. Finally, we take a practical approach in describing how we use the three techniques, including the common indications, contraindications, and practical aspects of application.

Consequences and Solutions for the Impact of Communication Impairment on Noninvasive Ventilation Therapy for Acute Respiratory Failure: A Focused Review

Objectives:

With over 2 million cases of acute respiratory failure in the United States per year, noninvasive ventilation has become a leading treatment modality, often supplanting invasive mechanical ventilation as the initial treatment of choice. Most acute respiratory failure patients use a full face (oronasal) mask with noninvasive ventilation, which is known to impair communication, but its popularity and benefit has led many providers to accept the communication impairment. Medical staff periodically remove masks to communicate with patients, but patients are often limited to short utterances and risk lung derecruitment upon removal of positive pressure. These problems can lead to noninvasive ventilation failure, which is often linked to worse outcomes than first initiating invasive mechanical ventilation and can lead to increased hospitalization costs.

Data Sources:

We searched MEDLINE and Google Scholar for “speech,” “communication,” “impairment,” “failure,” “complications,” “NIPPV,” “NIV,” and “noninvasive ventilation.”

Study Selection:

We included articles with patients in acute respiratory failure. We excluded articles for patients using noninvasive ventilation therapy for obstructive sleep apnea.

Data Synthesis:

Communication impairment has been associated with increasing noninvasive ventilation anxiety (odds ratio, 1.25). Of patients using noninvasive ventilation, 48% require early discontinuation, 22% refuse noninvasive ventilation, and 9% are ultimately intubated. Improvements to communication have been shown to reduce fear and anxiety in invasive mechanical ventilation patients. Analogous communication problems exist with effective solutions in other fields, such as fighter pilot masks, that can be easily implemented to enhance noninvasive ventilation patient care, increase adherence to noninvasive ventilation treatment, and improve patient outcomes.

Conclusions:

Communication impairment is an underappreciated cause of noninvasive ventilation complications and failure and requires further characterization. Analogous solutions—such as throat microphones and mask-based microphones—that can be easily implemented show potential as cost-effective methods to reduce noninvasive ventilation failure.

High flow nasal cannula oxygen versus noninvasive ventilation in adult acute respiratory failure: a systematic review of randomized-controlled trials

We reviewed the use of noninvasive ventilation (NIV) versus high flow nasal cannula (HFNC) oxygen in adult acute respiratory failure (ARF). We searched major databases and included randomized trials comparing at least NIV with HFNC or NIV+HFNC with NIV in ARF. Primary outcomes included intubation/re-intubation rates. Secondary outcomes were ICU mortality and morbidities. Five trials were included; three compared HFNC with NIV, one compared HFNC, NIV and oxygen whereas one compared HFNC+NIV with NIV. Patients had hypoxaemic ARF (PaO2/FiO2≤300 mmHg). Heterogeneity prevented result pooling. Three and two studies had superiority and noninferiority design, respectively. Patients were postcardiothoracic surgery, mixed medical/surgical patients and those with pneumonia. Two trials were conducted after extubation, two before intubation and one during intubation. Three trials reported intubation/re-intubation rates as the primary outcomes. The other two trials reported the lowest peripheral capillary oxygen saturation readings during bronchoscopy or intubation. In the former three trials, the odds ratio for intubation/re-intubation rates between HFNC versus the NIV group ranged from 0.80 (95% confidence interval: 0.54-1.19) to 1.65 (95% confidence interval: 0.96-2.84). In the latter two trials, only one reported a difference in the lowest peripheral capillary oxygen saturation between NIV+HFNC versus the NIV group during intubation [100% (interquartile range: 95-100) vs. 96% (interquartile range: 92-99); P=0.029]. The secondary outcomes included differences in ICU mortality and patient tolerability, favouring HFNC. Results were conflicting, but highlighted future research directions. These include patients with hypercapneic ARF, more severe hypoxaemia (PaO2/FiO2≤200 mmHg), a superiority design, an oxygen arm and patient-centred outcomes.

Cost-Minimization Analysis of Non-Invasive and Invasive Mechanical Ventilation for De Novo Acute Hypoxemic Respiratory Failure in an Eastern European Setting

Introduction: In the light of constant pressure for minimizing healthcare costs we made a cost-minimization analysis comparing invasive mechanical ventilation (IMV) and non-invasive ventilation (NIV) as treatment for hypoxemic acute respiratory failure (ARF).

Aim: The primary objective was to estimate the direct medical costs generated by a patient on IMV and NIV. A secondary objective was to identify which aspect of the treatment was most expensive.

Material and Methods: This is a single center retrospective study including 36 patients on mechanical ventilation due to hypoxemic ARF, separated in two groups – NIV (n = 18) and IMV (n = 18). We calculated all direct medical costs in Euro and compared them statistically.

Results: On admission the PaO2/FiO2 and SAPS II score were comparable in both groups. We observed a significant difference in the costs per patient for drug treatment (NIV: 616.07; IQR: 236.68, IMV:1456.18; IQR:1741.95, p = 0.005), consumables (NIV: 16.47; IQR: 21.44, IMV: 98.79; IQR: 81.52, p < 0.001) and diagnostic tests (NIV: 351; IQR: 183.88, IMV: 765.69; IQR: 851.43, p < 0.001). We also computed the costs per patient per day and there was a significant difference in the costs in all above listed categories. In both groups the highest costs were for drug treatment – around 61%.

Conclusions: In the setting of hypoxemic ARF NIV reduces significantly the direct medical costs of treatment in comparison to IMV. The decreased costs in NIV are not associated with severity of disease according to the respiratory quotient and SAPS II score.

Clinical characteristics and outcomes associated with nasal intermittent mandatory ventilation in acute pediatric respiratory failure

AIM

To characterize the clinical course and outcomes of nasal intermittent mandatory ventilation (NIMV) use in acute pediatric respiratory failure.

METHODS

We identified all patients treated with NIMV in the pediatric intensive care unit (PICU) or inpatient general pediatrics between January 2013 and December 2015 at two academic centers. Patients who utilized NIMV with other modes of noninvasive ventilation during the same admission were included. Data included demographics, vital signs on admission and prior to initiation of NIMV, pediatric risk of mortality III (PRISM-III) scores, complications, respiratory support characteristics, PICU and hospital length of stays, duration of respiratory support, and complications. Patients who did not require escalation to mechanical ventilation were defined as NIMV responders; those who required escalation to mechanical ventilation (MV) were defined as NIMV non-responders. NIMV responders were compared to NIMV non-responders.

RESULTS

Forty-two patients met study criteria. Six (14%) failed treatment and required MV. The majority of the patients (74%) had a primary diagnosis of bronchiolitis. The median age of these 42 patients was 4 mo (range 0.5-28.1 mo, IQR 7, P = 0.69). No significant difference was measured in other baseline demographics and vitals on initiation of NIMV; these included age, temperature, respiratory rate, O2 saturation, heart rate, systolic blood pressure, diastolic blood pressure, and PRISM-III scores. The duration of NIMV was shorter in the NIMV non-responder vs NIMV responder group (6.5 h vs 65 h, P < 0.0005). Otherwise, NIMV failure was not associated with significant differences in PICU length of stay (LOS), hospital LOS, or total duration of respiratory support. No patients had aspiration pneumonia, pneumothorax, or skin breakdown.

CONCLUSION

Most of our patients responded to NIMV. NIMV failure is not associated with differences in hospital LOS, PICU LOS, or duration of respiratory support.

What Is the Impact of Mildly Altered Consciousness on Acute Hypoxemic Respiratory Failure with Non-invasive Ventilation?

Objective A severely altered level of consciousness (ALC) is considered to be a possible contraindication to non-invasive ventilation (NIV). We investigated the association between mild ALC and NIV failure in patients with hypoxemic respiratory failure. Methods A retrospective study was conducted by reviewing the medical charts of patients with de novo hypoxemic respiratory failure who received NIV treatment. The clinical background and the outcomes of patients with and without ALC were compared. Patients Patients who were admitted to our hospital for acute hypoxemic respiratory failure between July 2011 and May 2015 were included in the present study. Results Sixty-six of the 148 patients had ALC. In comparison to the patients without ALC, the patients with ALC were older (median: 72 vs. 78 years, p=0.02), had a higher Acute Physiology and Chronic Health Evaluation II score (18 vs. 19, p=0.02), and received a higher level of inspiratory pressure (8 cmH2O vs. 8, p<0.01). The median Glasgow Coma Scale score of the patients with ALC was 14 (interquartile range, 11-14). There were no significant differences between the groups in the rates of NIV failure (24% vs. 30%, p=0.4) and in-hospital mortality (13% vs. 16%, p=0.3). Conclusion NIV may be successfully applied to treat acute hypoxemic respiratory failure with mild ALC. NIV may be performed, with careful attention to the appropriate timing for intubation.

Non-invasive ventilation use in status asthmaticus: 16 years of experience in a tertiary intensive care

OBJECTIVE

To describe the use of non-invasive ventilation (NIV) in adults presenting with status asthmaticus to Middlemore Hospital Critical Care Complex (CCC, South Auckland, New Zealand) from 2000 to 2015.

METHOD

Retrospective review of all adult asthma admissions to the Hospital CCC between 2000 and 2015. Demographic, physiological, treatment data and blood gas results were recorded.

RESULTS

There were 265 asthma admissions to Middlemore Hospital CCC during the study period. The median age was 34 years; 64% were female. NIV was used in 186 admissions, of which eight went on to require intubation and invasive mechanical ventilation (IMV). Twenty-three other admissions received IMV without a trial of NIV and a further 58 were managed with medical care only. The average pH for all admissions was 7.23 and the IMV group had an average pH of 6.99. Forty-five admissions presented with a Glasgow Coma Scale (GCS) score of ≤10. Twenty-five of these were managed with NIV with only one requiring subsequent intubation. The mean duration of NIV in this group was 5 h (range 1-17 h) with a mean ICU and hospital length of stay of 17 h and 3.5 days, respectively. All patients in this group effectively lowered the pCO₂ over a 2 h period with NIV having an average drop of 5.9 kPa and IMV 3.4 kPa.

CONCLUSION

The use of NIV appears to be safe and effective in patients with severe asthma, including selected patients with an altered level of consciousness. NIV was well tolerated with a low need for subsequent intubation.

Nosocomial bacterial infections and their antimicrobial susceptibility patterns among patients in Ugandan intensive care units: a cross sectional study

Background

The intensive care unit (ICU) admits critically ill patients requiring advanced airway, respiratory, cardiac and renal support. Despite the highly-specialized interventions, the mortality and morbidity is still high due to a number of reasons including nosocomial infections, which are the most likely complications in hospitalized patients with the rates being highest among ICU patients.

Methods

In this cross-sectional study of 111 adult patients admitted to 2 of the ICUs in Uganda, we set out to describe the commonest bacterial infections, their antimicrobial susceptibility patterns and factors associated with development of a nosocomial infection.

Results

Klebsiella pneumoniae (30%), Acinetobacter species (22%) and Staphylococcus aureus (14%) were the most frequently isolated bacteria. The prevalence of multidrug resistant bacterial species was 58%; 50% Escherichia coli and 33.3% Klebsiella pneumoniae were extended spectrum beta lactamase or AmpC beta lactamase producers and 9.1% Acinetobacter species were extensive drug resistant. Imipenem was the antibiotic with the highest susceptibility rates across most bacterial species. Institution of ventilator support (P 0.003) and severe traumatic brain injury (P 0.035) were highly associated with the development of nosocomial infections.

Conclusion

Due to the high prevalence of multi drug resistant (MDR) and extensive drug resistant bacterial species, there is a need for development of strong policies on antibiotic stewardship, antimicrobial surveillance and infection control to help guide empirical antibiotic therapy and prevent the spread of MDR bacteria and antibiotic drug resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2695-5) contains supplementary material, which is available to authorized users.

Non-invasive ventilation for the management of acute hypercapnic respiratory failure due to exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Non-invasive ventilation (NIV) with bi-level positive airway pressure (BiPAP) is commonly used to treat patients admitted to hospital with acute hypercapnic respiratory failure (AHRF) secondary to an acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

OBJECTIVES

To compare the efficacy of NIV applied in conjunction with usual care versus usual care involving no mechanical ventilation alone in adults with AHRF due to AECOPD. The aim of this review is to update the evidence base with the goals of supporting clinical practice and providing recommendations for future evaluation and research.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register of trials (CAGR), which is derived from systematic searches of bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Allied and Complementary Medicine Database (AMED), and PsycINFO, and through handsearching of respiratory journals and meeting abstracts. This update to the original review incorporates the results of database searches up to January 2017.

SELECTION CRITERIA

All randomised controlled trials that compared usual care plus NIV (BiPAP) versus usual care alone in an acute hospital setting for patients with AECOPD due to AHRF were eligible for inclusion. AHRF was defined by a mean admission pH < 7.35 and mean partial pressure of carbon dioxide (PaCO2) > 45 mmHg (6 kPa). Primary review outcomes were mortality during hospital admission and need for endotracheal intubation. Secondary outcomes included hospital length of stay, treatment intolerance, complications, changes in symptoms, and changes in arterial blood gases.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the selection criteria to determine study eligibility, performed data extraction, and determined risk of bias in accordance with Cochrane guidelines. Review authors undertook meta-analysis for data that were both clinically and statistically homogenous, and analysed data as both one overall pooled sample and according to two predefined subgroups related to exacerbation severity (admission pH between 7.35 and 7.30 vs below 7.30) and NIV treatment setting (intensive care unit-based vs ward-based). We reported results for mortality, need for endotracheal intubation, and hospital length of stay in a 'Summary of findings' table and rated their quality in accordance with GRADE criteria.

MAIN RESULTS

We included in the review 17 randomised controlled trials involving 1264 participants. Available data indicate that mean age at recruitment was 66.8 years (range 57.7 to 70.5 years) and that most participants (65%) were male. Most studies (12/17) were at risk of performance bias, and for most (14/17), the risk of detection bias was uncertain. These risks may have affected subjective patient-reported outcome measures (e.g. dyspnoea) and secondary review outcomes, respectively.Use of NIV decreased the risk of mortality by 46% (risk ratio (RR) 0.54, 95% confidence interval (CI) 0.38 to 0.76; N = 12 studies; number needed to treat for an additional beneficial outcome (NNTB) 12, 95% CI 9 to 23) and decreased the risk of needing endotracheal intubation by 65% (RR 0.36, 95% CI 0.28 to 0.46; N = 17 studies; NNTB 5, 95% CI 5 to 6). We graded both outcomes as 'moderate' quality owing to uncertainty regarding risk of bias for several studies. Inspection of the funnel plot related to need for endotracheal intubation raised the possibility of some publication bias pertaining to this outcome. NIV use was also associated with reduced length of hospital stay (mean difference (MD) -3.39 days, 95% CI -5.93 to -0.85; N = 10 studies), reduced incidence of complications (unrelated to NIV) (RR 0.26, 95% CI 0.13 to 0.53; N = 2 studies), and improvement in pH (MD 0.05, 95% CI 0.02 to 0.07; N = 8 studies) and in partial pressure of oxygen (PaO2) (MD 7.47 mmHg, 95% CI 0.78 to 14.16 mmHg; N = 8 studies) at one hour. A trend towards improvement in PaCO2 was observed, but this finding was not statistically significant (MD -4.62 mmHg, 95% CI -11.05 to 1.80 mmHg; N = 8 studies). Post hoc analysis revealed that this lack of benefit was due to the fact that data from two studies at high risk of bias showed baseline imbalance for this outcome (worse in the NIV group than in the usual care group). Sensitivity analysis revealed that exclusion of these two studies resulted in a statistically significant positive effect of NIV on PaCO2. Treatment intolerance was significantly greater in the NIV group than in the usual care group (risk difference (RD) 0.11, 95% CI 0.04 to 0.17; N = 6 studies). Results of analysis showed a non-significant trend towards reduction in dyspnoea with NIV compared with usual care (standardised mean difference (SMD) -0.16, 95% CI -0.34 to 0.02; N = 4 studies). Subgroup analyses revealed no significant between-group differences.

AUTHORS' CONCLUSIONS

Data from good quality randomised controlled trials show that NIV is beneficial as a first-line intervention in conjunction with usual care for reducing the likelihood of mortality and endotracheal intubation in patients admitted with acute hypercapnic respiratory failure secondary to an acute exacerbation of chronic obstructive pulmonary disease (COPD). The magnitude of benefit for these outcomes appears similar for patients with acidosis of a mild (pH 7.30 to 7.35) versus a more severe nature (pH < 7.30), and when NIV is applied within the intensive care unit (ICU) or ward setting.

Preventing Ventilator-Associated Infections

Mechanical ventilator use is fraught with risk of complications. Ventilator-associated pneumonia (VAP) is a common complication that prolongs stays on the ventilator and increases mortality and costs. The Centers for Disease Control and Prevention recommend the use of the term, ventilator-associated event. Prevention and/or interruption of cycle of inflammation, colonization of respiratory tract, and ventilator-associated tracheobronchitis are key to managing VAP. Modifying risk factors using a ventilator bundle is considered standard of care. The contentious factors and the lack of support for early tracheotomy, parenteral nutrition, and monitoring of gastric residuals are also addressed. Finally, the role of ventilator-associated tracheobronchitis in VAP is discussed.

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.

Management of acute hypercapnic respiratory failure

PURPOSE OF REVIEW

The objective of this article is to review the most recent literature regarding the management of acute hypercapnic respiratory failure (AHRF).

RECENT FINDINGS

In the field of AHRF management, noninvasive ventilation (NIV) has become the standard method of providing primary mechanical ventilator support. Recently, extracorporeal carbon dioxide removal (ECCO2R) devices have been proposed as new therapeutic option.

SUMMARY

NIV is an effective strategy in specific settings and in selected population with AHRF. To date, evidence on ECCO2R is based only on case reports and case-control trials. Although the preliminary results using ECCO2R to decrease the rate of NIV failure and to wean hypercapnic patients from invasive ventilation are remarkable; further randomized studies are needed to assess the effects of this technique on both short-term and long-term clinical outcomes.

Intensive care and invasive ventilation in the elderly patient, implications of chronic lung disease and comorbidities

Aims: Elderly patients have an increasing prevalence of illness that requires consideration of critical care and invasive ventilatory support. Although critical care of even the very elderly can provide value, with increasing age the potential risks of treatment and diminishing returns with respect to quality and quantity of life result in a need for careful evaluation. Variable combinations of impaired organ function, active disease and residual pathology from past disease and injury all affect critical care, with the consequence that the elderly are a very heterogeneous population. Recognizing that critical care is a limited resource, it is important to identify patients who may be at increased risk or least likely to benefit from treatment. Patients with functional impairments, nutritional deficiencies and multiple comorbidities may be at highest risk of poor outcomes. Those with very severe disease, extreme age and requirements for prolonged ventilatory support have high in-hospital mortality. Functional impairments, comorbidities and severity of illness are usually more important considerations than chronologic age. The objective of this review is to identify how common problems of the elderly affect critical care and decisions concerning use of invasive ventilatory support.

Inapparent Outbreaks of Ventilator-Associated Pneumonia An Ecologic Analysis of Prevention and Cohort Studies

Objective:

To compare ventilator-associated pneumonia (VAP) rates and patterns of isolates across studies of antibiotic and non-antibiotic methods for preventing VAP.

Design:

With the use of 42 cohort study groups as the reference standard, the prevalence of VAP was modeled in two linear regressions: one with the control groups and the other with the intervention groups of 96 VAP prevention studies. The proportion of patients admitted with trauma and the VAP diagnostic criteria were used as ecologic correlates. Also, the patterns of pathogenic isolates were available for 117 groups.

Results:

In the first regression model, the VAP rates for the control groups of antibiotic-based prevention studies were at least 18 (CI95, 12 to 24) per 100 patients higher than those in the cohort study groups (P< .001). By contrast, comparisons of cohort study groups with all other control and intervention groups in the first and second regression models yielded differences that were less than 6 per 100 and not significant (P> .05). For control groups with VAP rates greater than 35%, the patterns of VAP isolates, such as the proportion ofStaphylococcus aureus,more closely resembled those in the corresponding intervention groups than in the cohort groups.

Conclusions:

The rates of VAP in the control groups of the antibiotic prevention studies were significantly higher than expected and the patterns of pathogenic isolates were unusual. These observations suggest that inapparent outbreaks of VAP occurred in these studies. The possibility remains that antibiotic-based VAP prevention presents a major cross-infection hazard.

Initial empirical antibacterial therapy of ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) is the most frequently occurring nosocomial infection, accounting for considerable morbidity and mortality. Diagnosis can be difficult, creating important therapeutic challenges for intensivists. Early therapy is important in maximizing outcomes, but inappropriate antibacterial treatment has its own risks. A balance needs to be struck between the necessary therapeutic benefits and the negative effects (selection of resistant pathogens, costs, and adverse effects) of antibacterials. Several studies have indicated, in various groups of critically ill patients including those with VAP, that starting treatment with an ineffective antibacterial can increase hospital and intensive care unit length of stay and mortality. When the responsible microorganisms cannot be defined, it may be better to start treatment with a broad-spectrum antibacterial regimen, taking into account individual patient factors and local bacteriology patterns, including antibacterial resistance. As soon as the nature of the pathogen has been defined, the antibacterial agent(s) should be modified accordingly, with the primary aim to reduce the antibacterial spectrum. The optimal duration of therapy is controversial and probably best tailored to the individual patient depending on clinical response and resolution of the factors used to diagnose VAP in that patient. Consultation with an infectious disease specialist may facilitate these therapeutic decisions. With the high morbidity and mortality associated with VAP, prevention is an important issue. General measures include adequate hand hygiene. Physicians must be aware of the risk factors for VAP and of accepted and effective strategies of prevention.

The optimum timing to wean invasive ventilation for patients with AECOPD or COPD with pulmonary infection

COPD is characterized by a progressive decline in lung function and mental and physical comorbidities. It is a significant burden worldwide due to its growing prevalence, comorbidities, and mortality. Complication by bronchial-pulmonary infection causes 50%-90% of acute exacerbations of COPD (AECOPD), which may lead to the aggregation of COPD symptoms and the development of acute respiratory failure. Non-invasive or invasive ventilation (IV) is usually implemented to treat acute respiratory failure. However, ventilatory support (mainly IV) should be discarded as soon as possible to prevent the onset of time-dependent complications. To withdraw IV, an optimum timing has to be selected based on weaning assessment and spontaneous breathing trial or replacement of IV by non-IV at pulmonary infection control window. The former method is more suitable for patients with AECOPD without significant bronchial-pulmonary infection while the latter method is more suitable for patients with AECOPD with acute significant bronchial-pulmonary infection.

Management of Acute Exacerbation of Asthma and Chronic Obstructive Pulmonary Disease in the Emergency Department

Acute asthma and chronic obstructive pulmonary disease (COPD) exacerbations are the most common respiratory diseases requiring emergent medical evaluation and treatment. Asthma and COPD are chronic, debilitating disease processes that have been differentiated traditionally by the presence or absence of reversible airflow obstruction. Asthma and COPD exacerbations impose an enormous economic burden on the US health care budget. In daily clinical practice, it is difficult to differentiate these 2 obstructive processes based on their symptoms, and on their nearly identical acute treatment strategies; major differences are important when discussing anatomic sites involved, long-term prognosis, and the nature of inflammatory markers.

Noninvasive ventilation in acute respiratory failure from respiratory syncytial virus bronchiolitis

Objectives

The present study focused on respiratory syncytial virus bronchiolitis with respiratory failure. The aim of the study was to determine whether noninvasive ventilation reduces the need for endotracheal intubation or slows the clinical progression of acute respiratory syncytial virus bronchiolitis by reducing the incidence of infectious complications.

Methods

The present study was a retrospective cohort study. Cohort A was comprised of children who were admitted to the pediatric intensive and special care unit from 2003-2005 before starting noninvasive ventilation; cohort B was comprised of children who were admitted to the pediatric intensive and special care unit from 2006-2008 after starting noninvasive ventilation. With the exception of noninvasive ventilation, the therapeutic support was the same for the two groups. All children who were diagnosed with respiratory syncytial virus bronchiolitis and respiratory failure between November 2003 and March 2008 were included in the cohort. Demographic, clinical and blood gas variables were analyzed.

Results

A total of 162 children were included; 75% of the subjects were less than 3 months old. Group A included 64 children, and group B included 98 children. In group B, 34 of the children required noninvasive ventilation. The distributions of the variables age, preterm birth, congenital heart disease, cerebral palsy and chronic lung disease were similar between the two groups. On admission, the data for blood gas analysis and the number of apneas were not significantly different between the groups. In group B, fewer children required invasive ventilation (group A: 12/64 versus group B: 7/98; p=0.02), and there was a reduction in the number of cases of bacterial pneumonia (group A: 19/64 versus group B: 12/98; p=0.008). There was no record of mortality in either of the groups.

Conclusion

By comparing children with the same disease both before and after noninvasive ventilation was used for ventilation support, we verified a reduction in infectious complications and cases requiring intubation.

Noninvasive positive pressure ventilation for acute respiratory failure following upper abdominal surgery

BACKGROUND

Each year, more than four million abdominal surgeries are performed in the US and over 250,000 in England. Acute respiratory failure, a common complication that can affect 30% to 50% of people after upper abdominal surgery, can lead to significant morbidity and mortality. Noninvasive ventilation has been associated with lower rates of tracheal intubation in adults with acute respiratory failure, thus reducing the incidence of complications and mortality. This review compared the effectiveness and safety of noninvasive positive pressure ventilation (NPPV) versus standard oxygen therapy in the treatment of acute respiratory failure after upper abdominal surgery.

OBJECTIVES

To assess the effectiveness and safety of noninvasive positive pressure ventilation (NPPV), that is, continuous positive airway pressure (CPAP) or bilevel NPPV, in reducing mortality and the rate of tracheal intubation in adults with acute respiratory failure after upper abdominal surgery, compared to standard therapy (oxygen therapy), and to assess changes in arterial blood gas levels, hospital and intensive care unit (ICU) length of stay, gastric insufflation, and anastomotic leakage.

SEARCH METHODS

The date of the last search was 12 May 2015. We searched the following databases: the Cochrane Handbook for Systematic Reviews of Interventions (CENTRAL) (2015, Issue 5), MEDLINE (Ovid SP, 1966 to May 2015), EMBASE (Ovid SP, 1974 to May 2015); the physiotherapy evidence database (PEDro) (1999 to May 2015); the Cumulative Index to Nursing and Allied Health Literature (CINAHL, EBSCOhost, 1982 to May 2015), and LILACS (BIREME, 1986 to May 2015). We reviewed reference lists of included studies and contacted experts. We also searched grey literature sources. We checked databases of ongoing trials such as www.controlled-trials.com/ and www.trialscentral.org/. We did not apply language restrictions.

SELECTION CRITERIA

We selected randomized or quasi-randomized controlled trials involving adults with acute respiratory failure after upper abdominal surgery who were treated with CPAP or bilevel NPPV with, or without, drug therapy as standard medical care, compared to adults treated with oxygen therapy with, or without, standard medical care.

DATA COLLECTION AND ANALYSIS

Two authors independently selected and abstracted data from eligible studies using a standardized form. We evaluated study quality by assessing allocation concealment; random sequence generation; incomplete outcome data; blinding of participants, personnel, and outcome assessors; selective reporting; and adherence to the intention-to-treat (ITT) principle.

MAIN RESULTS

We included two trials involving 269 participants. The participants were mostly men (67%); the mean age was 65 years. The trials were conducted in China and Italy (one was a multicentre trial). Both trials included adults with acute respiratory failure after upper abdominal surgery. We judged both trials at high risk of bias. Compared to oxygen therapy, CPAP or bilevel NPPV may reduce the rate of tracheal intubation (risk ratio (RR) 0.25; 95% confidence interval (CI) 0.08 to 0.83; low quality evidence) with a number needed to treat for an additional beneficial outcome of 11. There was very low quality evidence that the intervention may also reduce ICU length of stay (mean difference (MD) -1.84 days; 95% CI -3.53 to -0.15). We found no differences for mortality (low quality evidence) and hospital length of stay. There was insufficient evidence to be certain that CPAP or NPPV had an effect on anastomotic leakage, pneumonia-related complications, and sepsis or infections. Findings from one trial of 60 participants suggested that bilevel NPPV, compared to oxygen therapy, may improve blood gas levels and blood pH one hour after the intervention (partial pressure of arterial oxygen (PaO2): MD 22.5 mm Hg; 95% CI 17.19 to 27.81; pH: MD 0.06; 95% CI 0.01 to 0.11; partial pressure of arterial carbon dioxide (PCO2) levels (MD -9.8 mm Hg; 95% CI -14.07 to -5.53). The trials included in this systematic review did not present data on the following outcomes that we intended to assess: gastric insufflation, fistulae, pneumothorax, bleeding, skin breakdown, eye irritation, sinus congestion, oronasal drying, and patient-ventilator asynchrony.

AUTHORS' CONCLUSIONS

The findings of this review indicate that CPAP or bilevel NPPV is an effective and safe intervention for the treatment of adults with acute respiratory failure after upper abdominal surgery. However, based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, the quality of the evidence was low or very low. More good quality studies are needed to confirm these findings.

[Noninvasive ventilation for acute respiratory failure in a pulmonary department]

INTRODUCTION

Noninvasive ventilation (NIV) is considered as the first choice treatment for selected patients with acute respiratory failure (ARF), but many hospitals are forced to start NIV on medical wards.

METHODS

The aim of this retrospective study was to assess the outcomes of NIV initiated for ARF on a respiratory ward and to find the criteria predictive of failure. All patients were treated in a four-bed ward specifically dedicated to NIV. Failure of NIV was defined as the need for intubation and transfer to ICU, or death.

RESULTS

Among 105 admissions with ARF, 49 episodes needed NIV. These episodes were divided into 2 groups: PaCO2<45mmHg (10) and PaCO2>45mmHg (39). The overall failure rate of NIV and overall in-hospital mortality rate were 26.5% and 17% respectively. On multivariate analysis, SAPS II and respiratory acidosis with a pH less than 7.30 were significantly associated with failure of NIV.

CONCLUSIONS

NIV is practicable and is effective in the management of mild to moderate ARF on a respiratory ward. However, patients with respiratory acidosis and a pH less than 7.30 are at risk of NIV failure.

Topical antibiotics as a major contextual hazard toward bacteremia within selective digestive decontamination studies: a meta-analysis

BACKGROUND

Among methods for preventing pneumonia and possibly also bacteremia in intensive care unit (ICU) patients, Selective Digestive Decontamination (SDD) appears most effective within randomized concurrent controlled trials (RCCT's) although more recent trials have been cluster randomized. However, of the SDD components, whether protocolized parenteral antibiotic prophylaxis (PPAP) is required, and whether the topical antibiotic actually presents a contextual hazard, remain unresolved. The objective here is to compare the bacteremia rates and patterns of isolates in SDD-RCCT's versus the broader evidence base.

METHODS

Bacteremia incidence proportion data were extracted from component (control and intervention) groups decanted from studies investigating antibiotic (SDD) or non-antibiotic methods of VAP prevention and summarized using random effects meta-analysis of study and group level data. A reference category of groups derived from purely observational studies without any prevention method under study provided a benchmark incidence.

RESULTS

Within SDD RCCTs, the mean bacteremia incidence among concurrent component groups not exposed to PPAP (27 control; 17.1%; 13.1-22.1% and 12 intervention groups; 16.2%; 9.1-27.3%) is double that of the benchmark bacteremia incidence derived from 39 benchmark groups (8.3; 6.8-10.2%) and also 20 control groups from studies of non-antibiotic methods (7.1%; 4.8 - 10.5). There is a selective increase in coagulase negative staphylococci (CNS) but not in Pseudomonas aeruginosa among bacteremia isolates within control groups of SDD-RCCT's versus benchmark groups with data available.

CONCLUSIONS

The topical antibiotic component of SDD presents a major contextual hazard toward bacteremia against which the PPAP component partially mitigates.

Continuous positive airway pressure and noninvasive ventilation in prehospital treatment of patients with acute respiratory failure: a systematic review of controlled studies

Continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV) are frequently used inhospital for treating respiratory failure, especially in treatment of acute cardiogenic pulmonary edema and exacerbation of chronic obstructive pulmonary disease. Early initiation of treatment is important for success and introduction already in the prehospital setting may be beneficial. Our goal was to assess the evidence for an effect of prehospital CPAP or NIV as a supplement to standard medical treatment alone on the following outcome measures; mortality, hospital length of stay, intensive care unit length of stay, and intubation rate. We undertook a systematic review based on a search in the three databases: PubMed, EMBASE, and Cochrane. We included 12 studies in our review, but only four of these were of acceptable size and quality to conclude on our endpoints of interest. All four studies examine prehospital CPAP. Of these, only one small, randomized controlled trial shows a reduced mortality rate and a reduced intubation rate with supplemental CPAP. The other three studies have neutral findings, but in two of these a trend toward lower intubation rate is found. The effect of supplemental NIV has only been evaluated in smaller studies with insufficient power to conclude on our endpoints. None of these studies have shown an effect on neither mortality nor intubation rate, but two small, randomized controlled trials show a reduction in intensive care unit length of stay and a trend toward lower intubation rate. The risk of both type two errors and publication bias is evident, and the findings are not consistent enough to make solid conclusion on supplemental prehospital NIV. Large, randomized controlled trials regarding the effect of NIV and CPAP as supplement to standard medical treatment alone, in the prehospital setting, are needed.

Infection control in the intensive care unit

It is critical for health care personnel to recognize and appreciate the detrimental impact of intensive care unit (ICU)-acquired infections. The economic, clinical, and social expenses to patients and hospitals are overwhelming. To limit the incidence of ICU-acquired infections, aggressive infection control measures must be implemented and enforced. Researchers and national committees have developed and continue to develop evidence-based guidelines to control ICU infections. A multifaceted approach, including infection prevention committees, antimicrobial stewardship programs, daily reassessments-intervention bundles, identifying and minimizing risk factors, and continuing staff education programs, is essential. Infection control in the ICU is an evolving area of critical care research.

Noninvasive ventilation in acute severe asthma: current evidence and future perspectives

PURPOSE OF REVIEW

The use of noninvasive positive pressure ventilation (NPPV) is often employed for the management of acute respiratory failure as an alternative to endotracheal intubation and mechanical ventilation. However, evidence to support the application of NPPV use in patients with acute severe asthma is less known.

RECENT FINDINGS

A paucity of evidence is available to support the use of NPPV as part of clinical care in patients with acute severe asthma. A number of small studies in adult and paediatric populations suggest that NPPV may have a beneficial role through improving respiratory rate and reducing the need for more invasive alternatives. Overall NPPV use appeared to be well tolerated with few reports of adverse events.

SUMMARY

Available evidence is limited by a small number of published trials and lack of methodological rigour in existing study design. There is a need for well conducted clinical studies to establish accurate treatment efficacy, safety and cost-effectiveness, in both the adult and paediatric setting.

Infection control in the intensive care unit

Nosocomial infections are common in many hospital departments, but particularly so on the intensive care unit, where they affect some 20 to 30% of patients. While early diagnosis and appropriate treatment are, of course, important, perhaps the greatest challenge is in the application of techniques to limit the development of such infections. This review will briefly discuss some of the background pathophysiology and epidemiology of nosocomial infection, and then focus on general and infection-specific preventative strategies individually and as part of broader infection-control programs with infection surveillance.

Noninvasive Positive-Pressure Ventilation in Patients with Acute Hypoxemic Respiratory Failure and HIV/AIDS

Pulmonary complications, especially acute respiratory failure (ARF), contribute to morbidity and mortality in immunocompromised patients. The etiology, pathophysiology, and reversibility of lung injury and the severity of ARF are key to the therapeutic response and prognosis for these patients.

Noninvasive ventilation as a weaning strategy for mechanical ventilation in adults with respiratory failure: a Cochrane systematic review

BACKGROUND

Noninvasive ventilation has been studied as a means of reducing complications among patients being weaned from invasive mechanical ventilation. We sought to summarize evidence comparing noninvasive and invasive weaning and their effects on mortality.

METHODS

We identified relevant randomized and quasirandomized trials through searches of databases, conference proceedings and grey literature. We included trials comparing extubation and immediate application of noninvasive ventilation with continued invasive weaning in adults on mechanical ventilation. Two reviewers each independently screened citations, assessed trial quality and abstracted data. Our primary outcome was mortality.

RESULTS

We identified 16 trials involving 994 participants, most of whom had chronic obstructive pulmonary disease (COPD). Compared with invasive weaning, noninvasive weaning significantly reduced mortality (risk ratio [RR] 0.53, 95% confidence interval [CI] 0.36 to 0.80), weaning failures (RR 0.63, 95% CI 0.42 to 0.96), ventilator-associated pneumonia (RR 0.25, 95% CI 0.15 to 0.43), length of stay in the intensive care unit (mean difference [MD] -5.59 d, 95% CI -7.90 to -3.28) and in hospital (MD -6.04 d, 95% CI -9.22 to -2.87), and total duration of mechanical ventilation (MD -5.64 d, 95% CI -9.50 to -1.77). Noninvasive weaning had no significant effect on the duration of ventilation related to weaning, but significantly reduced rates of tracheostomy (RR 0.19, 95% CI 0.08 to 0.47) and reintubation (RR 0.65, 95% CI 0.44 to 0.97). Mortality benefits were significantly greater in trials enrolling patients with COPD than in trials enrolling mixed patient populations (RR 0.36 [95% CI 0.24 to 0.56] v. RR 0.81 [95% CI 0.47 to 1.40]).

INTERPRETATION

Noninvasive weaning reduces rates of death and pneumonia without increasing the risk of weaning failure or reintubation. In subgroup analyses, mortality benefits were significantly greater in patients with COPD.

Noninvasive positive-pressure ventilation as a weaning strategy for intubated adults with respiratory failure

BACKGROUND

Noninvasive positive-pressure ventilation (NPPV) provides ventilatory support without the need for an invasive airway. Interest has emerged in using NPPV to facilitate earlier removal of an endotracheal tube and to decrease complications associated with prolonged intubation.

OBJECTIVES

We evaluated studies in which invasively ventilated adults with respiratory failure of any cause (chronic obstructive pulmonary disease (COPD), non-COPD, postoperative, nonoperative) were weaned by means of early extubation followed by immediate application of NPPV or continued IPPV weaning. The primary objective was to determine whether the noninvasive positive-pressure ventilation (NPPV) strategy reduced all-cause mortality compared with invasive positive-pressure ventilation (IPPV) weaning. Secondary objectives were to ascertain differences between strategies in proportions of weaning failure and ventilator-associated pneumonia (VAP), intensive care unit (ICU) and hospital length of stay (LOS), total duration of mechanical ventilation, duration of mechanical support related to weaning, duration of endotracheal mechanical ventilation (ETMV), frequency of adverse events (related to weaning) and overall quality of life. We planned sensitivity and subgroup analyses to assess (1) the influence on mortality and VAP of excluding quasi-randomized trials, and (2) effects on mortality and weaning failure associated with different causes of respiratory failure (COPD vs. mixed populations).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 5, 2013), MEDLINE (January 1966 to May 2013), EMBASE (January 1980 to May 2013), proceedings from four conferences, trial registration websites and personal files; we contacted authors to identify trials comparing NPPV versus conventional IPPV weaning.

SELECTION CRITERIA

Randomized and quasi-randomized trials comparing early extubation with immediate application of NPPV versus IPPV weaning in intubated adults with respiratory failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and abstracted data according to prespecified criteria. Sensitivity and subgroup analyses assessed (1) the impact of excluding quasi-randomized trials, and (2) the effects on selected outcomes noted with different causes of respiratory failure.

MAIN RESULTS

We identified 16 trials, predominantly of moderate to good quality, involving 994 participants, most with chronic obstructive pulmonary disease (COPD). Compared with IPPV weaning, NPPV weaning significantly decreased mortality. The benefits for mortality were significantly greater in trials enrolling exclusively participants with COPD (risk ratio (RR) 0.36, 95% confidence interval (CI) 0.24 to 0.56) versus mixed populations (RR 0.81, 95% CI 0.47 to 1.40). NPPV significantly reduced weaning failure (RR 0.63, 95% CI 0.42 to 0.96) and ventilator-associated pneumonia (RR 0.25, 95% CI 0.15 to 0.43); shortened length of stay in an intensive care unit (mean difference (MD) -5.59 days, 95% CI -7.90 to -3.28) and in hospital (MD -6.04 days, 95% CI -9.22 to -2.87); and decreased the total duration of ventilation (MD -5.64 days, 95% CI -9.50 to -1.77) and the duration of endotracheal mechanical ventilation (MD - 7.44 days, 95% CI -10.34 to -4.55) amidst significant heterogeneity. Noninvasive weaning also significantly reduced tracheostomy (RR 0.19, 95% CI 0.08 to 0.47) and reintubation (RR 0.65, 95% CI 0.44 to 0.97) rates. Noninvasive weaning had no effect on the duration of ventilation related to weaning. Exclusion of a single quasi-randomized trial did not alter these results. Subgroup analyses suggest that the benefits for mortality were significantly greater in trials enrolling exclusively participants with COPD versus mixed populations.

AUTHORS' CONCLUSIONS

Summary estimates from 16 trials of moderate to good quality that included predominantly participants with COPD suggest that a weaning strategy that includes NPPV may reduce rates of mortality and ventilator-associated pneumonia without increasing the risk of weaning failure or reintubation.

Neuroanesthesia and Intensive Care A meta-analysis of noninvasive weaning to facilitate liberation from mechanical ventilation

PURPOSE

To summarize the evidence comparing noninvasive positive pressure ventilation (NPPV) and invasive positive pressure ventilation (IPPV) weaning on mortality, ventilator associated pneumonia and the total duration of mechanical ventilation among invasively ventilated adults with respiratory failure.

SOURCE

Meta-analysis of randomized and quasi-randomized studies comparing early extubation with immediate application of NPPV to IPPV weaning. We selected randomized studies that 1) included adults, with respiratory failure, invasively ventilated for at least 24 hr; 2) compared extubation with immediate application of NPPV to weaning using IPPV; and 3) reported at least one clinically important outcome.

PRINCIPAL FINDINGS

We searched MEDLINE (1966 to 2003), EMBASE (1980 to 2003) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003) for randomized controlled trials comparing NPPV and IPPV weaning. Additional data sources included personal files, conference proceedings and author contact. Two reviewers independently assessed trial quality and abstracted data. Five studies enrolling 171 patients demonstrated that compared to IPPV, noninvasive weaning decreased mortality (relative risk, 0.41 [95% confidence interval [CI] 0.22-0.76]), ventilator associated pneumonia (relative risk, 0.28 [95% CI 0.09-0.85]) and the total duration of mechanical ventilation (weighted mean difference, -7.33 days [95% CI -11.45 to -3.22 days]).

CONCLUSIONS

In the absence of a large randomized controlled trial, this meta-analysis demonstrated a consistent positive effect of noninvasive weaning on mortality. Notwithstanding, the use of NPPV to facilitate weaning, in mechanically ventilated patients, with predominantly chronic obstructive pulmonary disease, is associated with promising, but insufficient, evidence of net clinical benefit at present.

Prolonged emergency department length of stay is not associated with worse outcomes in patients with intracerebral hemorrhage

BACKGROUND

Prolonged emergency department length of stay (EDLOS) has been associated with worse patient outcomes, longer inpatient stays, and failure to meet quality measures in several acute medical conditions, but these findings have not been consistently reproduced. We performed this study to explore the hypothesis that longer EDLOS would be associated with worse outcomes in a large cohort of patients presenting with spontaneous intracerebral hemorrhage (ICH).

METHODS

We performed a secondary analysis of a prospective cohort of consecutive patients with spontaneous ICH who presented to a single academic referral center from February 2005 to October 2009. The primary exposure variable was EDLOS, and our primary outcome was neurologic status at hospital discharge, measured with a modified Rankin scale (mRS). Secondary outcomes were ICU length of stay, total hospital length of stay, and total hospital costs.

RESULTS

Our cohort included 616 visits of which 42 were excluded, leaving 574 patient encounters for analysis. Median age was 75 years (IQR 63-82), median EDLOS 5.1 h (IQR 3.7-7.1) and median discharge mRS 4 (IQR 3-6). Thirty percent of the subjects died in-hospital. Multivariable proportional odds logistic regression, controlling for age, initial Glasgow Coma Scale, initial hematoma volume, ED occupancy at registration, and the need for intubation or surgical intervention, demonstrated no association between EDLOS and outcome. Furthermore, multivariable analysis revealed no association of increased EDLOS with ICU or hospital length of stay or hospital costs.

CONCLUSION

We found no effect of EDLOS on neurologic outcome or resource utilization for patients presenting with spontaneous ICH.

Noninvasive ventilation in chest trauma: systematic review and meta-analysis

PURPOSE

Single studies of Noninvasive Ventilation (NIV) in the management of acute respiratory failure in chest trauma patients have produced controversial findings. The aim of this study is to critically review the literature to investigate whether NIV reduces mortality, intubation rate, length of stay and complications in patients with chest trauma, compared to standard therapy.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials, prospective and retrospective observational studies, by searching PubMed, EMBASE and bibliographies of articles retrieved. We screened for relevance studies that enrolled adults with chest trauma who developed mild to severe acute respiratory failure and were treated with NIV. We included studies reporting at least one clinical outcome of interest to perform a meta-analysis.

RESULTS

Ten studies (368 patients) met the inclusion criteria and were included for the meta-analysis. Five studies (219 patients) reported mortality and results were quite homogeneous across studies, with a summary relative risk for patients treated with NIV compared with standard care (oxygen therapy and invasive mechanical ventilation) of 0.26 (95 % confidence interval 0.09-0.71, p = 0.003). There was no advantage in mortality of continuous positive airway pressure over noninvasive pressure support ventilation. NIV significantly increased arterial oxygenation and was associated with a significant reduction in intubation rate, in the incidence of overall complications and infections.

CONCLUSIONS

These results suggest that NIV could be useful in the management of acute respiratory failure due to chest trauma.

Noninvasive mechanical ventilation with average volume assured pressure support (AVAPS) in patients with chronic obstructive pulmonary disease and hypercapnic encephalopathy

BACKGROUND

Non-invasive mechanical ventilation (NIV) in patients with acute respiratory failure has been traditionally determined based on clinical assessment and changes in blood gases, with NIV support pressures manually adjusted by an operator. Bilevel positive airway pressure-spontaneous/timed (BiPAP S/T) with average volume assured pressure support (AVAPS) uses a fixed tidal volume that automatically adjusts to a patient's needs. Our study assessed the use of BiPAP S/T with AVAPS in patients with chronic obstructive pulmonary disease (COPD) and hypercapnic encephalopathy as compared to BiPAP S/T alone, upon immediate arrival in the Emergency-ICU.

METHODS

We carried out a prospective interventional match-controlled study in Guayaquil, Ecuador. A total of 22 patients were analyzed. Eleven with COPD exacerbations and hypercapnic encephalopathy with a Glasgow Coma Scale (GCS) <10 and a pH of 7.25-7.35 were assigned to receive NIV via BiPAP S/T with AVAPS. Eleven patients were selected as paired controls for the initial group by physicians who were unfamiliar with our study, and these patients were administered BiPAP S/T. Arterial blood gases, GCS, vital signs, and ventilatory parameters were then measured and compared between the two groups.

RESULTS

We observed statistically significant differences in favor of the BiPAP S/T + AVAPS group in GCS (P = .00001), pCO(2) (P = .03) and maximum inspiratory positive airway pressure (IPAP) (P = .005), among others. However, no significant differences in terms of length of stay or days on NIV were observed.

CONCLUSIONS

BiPAP S/T with AVAPS facilitates rapid recovery of consciousness when compared to traditional BiPAP S/T in patients with chronic obstructive pulmonary disease and hypercapnic encephalopathy.

TRIAL REGISTRATION

Current Controlled Trials application ref is ISRCTN05135218.

Epidemiology and outcomes of acute respiratory failure in the United States, 2001 to 2009: a national survey

BACKGROUND

The objective of this study was to evaluate trends in hospitalization, cost, and short-term outcomes in acute respiratory failure (ARF) between 2001 and 2009 in the United States.

METHODS

Using the Nationwide Inpatient Sample we identified cases of ARF based on International Classification for Diseases, Ninth Revision, Clinical Modification codes. We calculated weighted frequencies of ARF hospitalizations by year and estimated population-adjusted incidence and mortality rates. We used logistic regression to examine hospital mortality rates over time while adjusting for changes in demographic characteristics and comorbidities of patients.

RESULTS

The number of hospitalizations with a diagnosis of ARF rose from 1,007,549 in 2001 to 1,917,910 in 2009, with an associated increase in total hospital costs from $30.1 billion to $54.3 billion. During the same period we observed a decrease in hospital mortality from 27.6% in 2001 to 20.6% in 2009, a slight decline in average length of stay from 7.8 days to 7.1 days, and no significant change in the mean cost per case ($15,900). Rates of mechanical ventilation (noninvasive [NIV] or invasive mechanical ventilation [IMV]) remained stable over the 9-year period, and the use of NIV increased from 4% in 2001 to 10% in 2009.

CONCLUSIONS

Over the period of 2001 to 2009, there was a steady increase in the number of hospitalizations with a discharge diagnosis of ARF, with a decrease in inpatient mortality. There was a significant shift during this time toward the use of NIV, with a decrease in the rates of IMVuse.

Non-invasive positive pressure ventilation for treatment of respiratory failure due to severe acute exacerbations of asthma

BACKGROUND

Asthma is a chronic respiratory condition causing inflammation and changes to the airways. Care of people with asthma includes routine and urgent management across primary and tertiary care; however, due to sub-optimal long-term care and delays in obtaining help during acute exacerbations, the mortality and morbidity related to asthma is still a major health concern. There is reason to believe that non-invasive positive pressure ventilation (NPPV) could be beneficial to patients with severe acute asthma; however, the evidence surrounding the efficacy of NPPV is unclear, despite its common use in clinical practice.

OBJECTIVES

To determine the efficacy of NPPV in adults with severe acute asthma in comparison to usual medical care with respect to mortality, tracheal intubation, changes in blood gases and hospital length of stay.

SEARCH METHODS

We carried out a search in the Cochrane Airways Group Specialised Register of trials (July 2012). Following this, the bibliographies of included studies and review articles were searched for additional studies (July 2012).

SELECTION CRITERIA

We included randomised controlled trials of adults with severe acute asthma as the primary reason for presentation to the emergency department or for admission to hospital. Asthma diagnosis was defined by internationally accepted criteria. Studies were included if the intervention was usual medical care for the management of severe acute asthma plus NPPV applied through a nasal or facemask compared to usual medical care alone. Studies including patients with features of chronic obstructive pulmonary disease (COPD) were excluded unless data were provided separately for patients with asthma in studies recruiting both COPD and asthmatic patients.

DATA COLLECTION AND ANALYSIS

A combination of two review authors independently assessed trial quality and extracted data. Study authors were contacted for additional information where required. All data were analysed using RevMan 5.1. For continuous variables, a mean difference and 95% confidence interval were used and for dichotomous variables, risk ratio with 95% confidence interval were calculated.

MAIN RESULTS

We identified six trials for inclusion. Five studies on 206 participants contributed data, while one study was available in abstract form only and was not fully incorporated into this review. For the primary outcome of endotracheal intubation there were two studies that contributed data: two intubations were needed in 45 participants on NPPV and no intubations in 41 control patients (risk ratio 4.48; 95% CI 0.23 to 89.13). There were no deaths in either of these studies. Length of hospital stay was reported in two studies, though meta-analysis was not possible. Hospitalisation was reported in one small study, in which there were three admissions out of 17 on NPPV and 10 admissions out of 16 in control patients (RR 0.28, 95% CI 0.09, 0.84).

AUTHORS' CONCLUSIONS

This review of studies has highlighted the paucity of data that exist to support the use of NPPV in patients in status asthmaticus. As such this course of treatment remains controversial despite its continued use in current clinical practice. Larger, prospective randomised controlled trials of rigorous methodological design are needed to determine the role of NPPV in patients with asthma.

Patient-ventilator asynchrony during noninvasive ventilation: a bench and clinical study

BACKGROUND

Different kinds of ventilators are available to perform noninvasive ventilation (NIV) in ICUs. Which type allows the best patient-ventilator synchrony is unknown. The objective was to compare patient-ventilator synchrony during NIV between ICU, transport—both with and without the NIV algorithm engaged—and dedicated NIV ventilators.

METHODS

First, a bench model simulating spontaneous breathing efforts was used to assess the respective impact of inspiratory and expiratory leaks on cycling and triggering functions in 19 ventilators. Second, a clinical study evaluated the incidence of patient-ventilator asynchronies in 15 patients during three randomized, consecutive, 20-min periods of NIV using an ICU ventilator with and without its NIV algorithm engaged and a dedicated NIV ventilator. Patient-ventilator asynchrony was assessed using flow, airway pressure, and respiratory muscles surface electromyogram recordings.

RESULTS

On the bench, frequent auto-triggering and delayed cycling occurred in the presence of leaks using ICU and transport ventilators. NIV algorithms unevenly minimized these asynchronies, whereas no asynchrony was observed with the dedicated NIV ventilators in all except one. These results were reproduced during the clinical study: The asynchrony index was significantly lower with a dedicated NIV ventilator than with ICU ventilators without or with their NIV algorithm engaged (0.5% [0.4%-1.2%] vs 3.7% [1.4%-10.3%] and 2.0% [1.5%-6.6%], P < .01), especially because of less auto-triggering.

CONCLUSIONS

Dedicated NIV ventilators allow better patient-ventilator synchrony than ICU and transport ventilators, even with their NIV algorithm. However, the NIV algorithm improves, at least slightly and with a wide variation among ventilators, triggering and/or cycling off synchronization.

Protocol-directed versus physician-directed weaning from noninvasive ventilation: the impact in chronic obstructive pulmonary disease patients

BACKGROUND

Noninvasive ventilation (NIV), a technique widely used in intensive care units (ICUs), eliminates the need for many patients in respiratory failure to undergo intubation. However, few articles have described how to wean patients from NIV. Herein, we put forward a protocol to be performed by respiratory therapists to wean patients from NIV.

METHODS

A prospective, randomized, controlled trial was performed in a respiratory ICU of a teaching hospital. Respiratory therapists screened patients daily. In the protocol-directed weaning group, the weaning attempt was initiated according to the protocol. In the physician-directed weaning group, the weaning attempt was initiated according to physicians' orders.

RESULTS

At randomization, patients in the two groups had similar clinical characteristics. A total of 73 patients were successfully weaned from NIV (37 in the protocol-directed group and 36 in the physician-directed group). The preponderance of them (64%) was chronic obstructive pulmonary disease patients. Compared with physician-directed weaning, protocol-directed weaning reduced the duration of NIV (4.4 ± 2.5 days vs. 2.6 ± 1.5 days, respectively, p < 0.001) and the duration of the ICU stay (8.1 ± 5.5 days vs. 5.8 ± 2.7 days, respectively, p = 0.02). In the protocol-directed group, the successful weaning rate was 57%, 27%, 13%, 0%, and 3% on the 1st, 2nd, 3rd, 4th, and 5th days after randomization, respectively.

CONCLUSIONS

Protocol-directed weaning reduces the duration of NIV and the duration of the ICU stay.

LEVEL OF EVIDENCE

II.

Clinical practice guidelines for hospital-acquired pneumonia and ventilator-associated pneumonia in adults

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are important causes of morbidity and mortality, with mortality rates approaching 62%. HAP and VAP are the second most common cause of nosocomial infection overall, but are the most common cause documented in the intensive care unit setting. In addition, HAP and VAP produce the highest mortality associated with nosocomial infection. As a result, evidence-based guidelines were prepared detailing the epidemiology, microbial etiology, risk factors and clinical manifestations of HAP and VAP. Furthermore, an approach based on the available data, expert opinion and current practice for the provision of care within the Canadian health care system was used to determine risk stratification schemas to enable appropriate diagnosis, antimicrobial management and nonantimicrobial management of HAP and VAP. Finally, prevention and risk-reduction strategies to reduce the risk of acquiring these infections were collated. Future initiatives to enhance more rapid diagnosis and to effect better treatment for resistant pathogens are necessary to reduce morbidity and improve survival.