Noninvasive ventilation in acute respiratory failure

Cost-effectiveness and clinical outcomes comparison between noninvasive ventilation and high-flow nasal cannula use in patients with multiple rib fractures

BACKGROUND

Patients with multiple rib fractures often require advanced respiratory support to prevent intubation and associated morbidity. Noninvasive ventilation (NIV) and high-flow nasal cannula (HFNC) are commonly used, but direct comparisons of clinical outcomes and cost-effectiveness remain limited. This study aimed to compare NIV versus HFNC using a large, nationwide US database.

METHODS

This retrospective cohort study used the 2020-2021 National Inpatient Sample database to identify adult trauma patients (18-89 years) with two or more rib fractures who received either NIV or HFNC without prior intubation. To focus on isolated thoracic injuries, patients with significant injuries elsewhere (Abbreviated Injury Scale score ≥3) or who died within 24 hours were excluded. Inverse probability of treatment of weighting was used to balance patient characteristics, including demographics, comorbidities, and injury severity. Primary outcomes included mortality, tracheostomy, pulmonary complications, and intubation rates. Hospital length of stay and total costs were also assessed. Cost-effectiveness analyses were conducted with intubation avoidance as the effectiveness measure, and a willingness-to-pay threshold of US $50,000 per effectiveness unit was used.

RESULTS

After adjustment, the NIV group demonstrated significantly better outcomes compared with HFNC, including lower mortality (11.4% vs. 17.0%, p = 0.007) and tracheostomy (1.2% vs. 3.1%, p = 0.006), and fewer pulmonary complications. Although intubation rates were not statistically different (12.0% vs. 15.6%, p = 0.085), the HFNC group had longer length of stay (13 vs. 10 days, p < 0.001) and incurred higher costs (US $42,505 vs. US $32,024, p < 0.001). Cost-effectiveness analysis revealed that NIV dominated HFNC, yielding better outcomes at lower costs.

CONCLUSION

Among patients with multiple rib fractures, NIV yielded superior clinical outcomes, shortened hospital stays, and reduced costs compared with HFNC. These findings suggest that NIV may be a more cost-effective and clinically advantageous choice.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Severe asthma exacerbation: Changes in patient characteristics, management, and outcomes from 1997 to 2016 in 40 ICUs in the greater Paris area

Background

Despite advances in asthma treatments, severe asthma exacerbation (SAE) remains a life-threatening condition in adults, and there is a lack of data derived from adult patients admitted to intensive care units (ICUs) for SAE. The current study investigated changes in adult patient characteristics, management, and outcomes of SAE over a 20-year period in 40 ICUs in the greater Paris area.

Methods

In this retrospective observational study, admissions to 40 ICUs in the greater Paris area for SAE from January 1, 1997, to December 31, 2016 were analyzed. The primary outcome was the proportion of ICU admissions for SAE during 5-year periods. Secondary outcomes were ICU and hospital mortality, and the use of mechanical ventilation and catecholamine. Multivariate analysis was performed to assess factors associated with ICU mortality.

Results

A total of 7049 admissions for SAE were recorded. For each 5-year period, the proportion decreased over time, with SAE accounting for 2.84% of total ICU admissions (n=2841) between 1997 and 2001, 1.76% (n=1717) between 2002 and 2006, 1.05% (n=965) between 2007 and 2011, and 1.05% (n=1526) between 2012 and 2016. The median age was 46 years (interquartile range [IQR]: 32-59 years), 55.41% were female, the median Simplified Acute Physiology Score II was 20 (IQR: 13-28), and 19.76% had mechanical ventilation. The use of mechanical ventilation remained infrequent throughout the 20-year period, whereas the use of catecholamine decreased. ICU and hospital mortality rates decreased. Factors associated with ICU mortality were renal replacement therapy, catecholamine, cardiac arrest, pneumothorax, acute respiratory distress syndrome, sepsis, and invasive mechanical ventilation (IMV). Non-survivors were older, had more severe symptoms, and were more likely to have received IMV.

Conclusion

ICU admission for SAE remains uncommon, and the proportion of cases decreased over time. Despite a slight increase in symptom severity during a 20-year period, ICU and hospital mortality decreased. Patients requiring IMV had a higher mortality rate.

Comparative evaluation of three total full-face masks for delivering Non-Invasive Positive Pressure Ventilation (NPPV): a bench study

Historically, the oro-nasal mask has been the preferred interface to deliver Non-Invasive Positive Pressure Ventilation (NPPV) in critically ill patients. To overcome the problems related to air leaks and discomfort, Total Full-face masks have been designed. No study has comparatively evaluated the performance of the total Full-face masks available.The aim of this bench study was to evaluate the influence of three largely diffuse models of total Full -face masks on patient-ventilator synchrony and performance during pressure support ventilation. NPPV was applied to a mannequin, connected to an active test lung through three largely diffuse Full-face masks: Dimar Full-face mask (DFFM), Performax Full-face mask (RFFM) and Pulmodyne Full-face mask (PFFM).The performance analysis showed that the ΔPtrigger was significantly lower with PFFM (p < 0.05) at 20 breaths/min (RRsim) at both pressure support (iPS) levels applied, while, at RRsim 30, DFFM had the longest ΔPtrigger compared to the other 2 total full face masks (p < 0.05). At all ventilator settings, the PTP200 was significantly shorter with DFFM than with the other two total full-face masks (p < 0.05). In terms of PTP500 ideal index (%), we did not observe significant differences between the interfaces tested.The PFFM demonstrated the best performance and synchrony at low respiratory rates, but when the respiratory rate increased, no difference between all tested total full-face masks was reported.

Oribron: An Origami-Inspired Deformable Rigid Bronchoscope for Radial Support

The structure of a traditional rigid bronchoscope includes proximal, distal, and body, representing an important means to treat hypoxic diseases. However, the body structure is too simple, resulting in the utilization rate of oxygen being usually low. In this work, we reported a deformable rigid bronchoscope (named Oribron) by adding a Waterbomb origami structure to the body. The Waterbomb's backbone is made of films, and the pneumatic actuators are placed inside it to achieve rapid deformation at low pressure. Experiments showed that Waterbomb has a unique deformation mechanism, which can transform from a small-diameter configuration (#1) to a large-diameter configuration (#2), showing excellent radial support capability. When Oribron entered or left the trachea, the Waterbomb remained in #1. When Oribron is working, the Waterbomb transforms from #1 to #2. Since #2 reduces the gap between the bronchoscope and the tracheal wall, it effectively slows down the rate of oxygen loss, thus promoting the absorption of oxygen by the patient. Therefore, we believe that this work will provide a new strategy for the integrated development of origami and medical devices.

High-Flow Nasal Cannula Oxygen Therapy versus Non-Invasive Ventilation for AECOPD Patients After Extubation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

To evaluate the clinical efficacy of high-flow nasal oxygen therapy (HFNC) and non-invasive ventilation (NIV) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) after extubation.

Research Methods

This systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) statements. The primary outcome measures analyzed included: reintubation rate, mortality, complication rate, and ICU length of stay.

Results

Eight studies were included, with a total of 612 subjects, including 297 in the HFNC group and 315 in the NIV group. The effect of HFNC and NIV on the reintubation rate of AECOPD patients after extubation, RR (1.49 [95% CI,0.95 to 2.33], P = 0.082). Subgroup analysis with or without hypercapnia according to the included AECOPD population, with hypercapnia, RR (0.69 [95% CI,0.33 to 1.44], P=0.317), without hypercapnia, RR (2.61 [95% CI,1.41 to 4.83], P=0.002). Mortality, RR (0.92 [95% CI,0.56 to 1.52], P = 0.752). ICU length of stay, MD (-0.44 [95% CI,-1.01 to 0.13], P = 0.132). Complication rate, RR (0.22 [95% CI,0.13 to 0.39], P = 0.000). After subgroup analysis, the reintubation rate of HFNC and NIV has no statistical difference in patients with hypercapnia, but NIV can significantly reduce the reintubation rate in patients without hypercapnia. In the outcome measures of complication rate, HFNC significantly reduced complication rate compared with NIV. In mortality and ICU length of stay, analysis results showed that HFNC and NIV were not statistically different.

Conclusion

According to the available evidence, the application of HFNC can be used as an alternative treatment for NIV after extubation in AECOPD patients with hypercapnia, but in the patients without hypercapnia, HFNC is less effective than NIV.

Principio de proporcionalidad terapéutica en la decisión de intubación orotraqueal y ventilación mecánica invasiva en paciente COVID-19 grave

En medicina cuando se aplica el principio de proporcionalidad terapéutica se valoran los medios empleados y el fin previsible en cada paciente. Y se distingue entre tratamientos proporcionados o desproporcionados, valorando el beneficio y utilidad. Entre ellos su aplicación en el paciente COVID-19 grave que requiere intubación orotraqueal y ventilación mecánica invasiva. En ocasiones nos puede generar el dilema ético de proceder a realizar dicho procedimiento y no encontrar beneficio alguno, sino al contrario generar sufrimiento, dolor y prolongación de su posible agonía. Teniendo el deber ético en estos casos de no abandonar sino acompañar a través de los cuidados paliativos, siempre informando al familiar sobre la decisión que se tome. El analizar este principio de proporcionalidad terapéutica y su aplicación en las unidades de cuidado intensivo requiere de una conciencia moral por parte del grupo que tiene la responsabilidad de la toma de la decisiòn y dirimir el dilema ético que se presente. Recordando que a los pacientes que requieran intubación orotraqueal se les deben ofrecer todas las medidas requeridas en ventilación mecánica invasiva y no invasiva para mejoría de la hipoxemia.

Se presenta un análisis y reflexión sobre el principio de proporcionalidad terapéutica y su fundamentación ética al igual que una revisión sistemática de la literatura médica relacionada con pacientes con COVID-19 en insuficiencia respiratoria aguda. Y se establecen unas consideraciones científicas y éticas a tener en cuenta en el paciente COVID-19. El principio de proporcionalidad terapéutica ante la decisión de intubación orotraqueal debe fundamentarse en un juicio de proporcionalidad, que garantice que se han hecho y utilizado todos los medios previsibles para evitar la intubación orotraqueal y como único fin útil para beneficiar al paciente será la ventilación mecánica invasiva.

Clinical Practice and Barriers of Ventilatory Support Management in COVID-19 Patients in Saudi Arabia: A Survey of Respiratory Therapists

Objective:

This study was conducted to determine the clinical practice and barriers of ventilatory support management in COVID-19 patients in Saudi Arabia among respiratory therapists.

Methods:

A validated questionnaire comprising three parts was distributed to all critical care respiratory therapists registered with the Saudi Society for Respiratory Care through the official social networks.

Results:

A total of 74 respiratory therapists completed the survey. The mean (±standard deviation) of intensive care unit beds was 67 ± 79. Clinical presentation (54%) and arterial blood gas (38%) were the two main diagnostic tools used to initiate ventilatory support. While protocols for the initiation of invasive mechanical ventilation (IMV; 81%) were widely available, participants had limited availability of protocols for the use of non-invasive ventilation (NIV; 34%) and high-flow nasal cannula (HFNC; 34%). In mild cases of COVID-19, most respondents used HFNC (57%), while IMV was mostly used in moderate (43%) and severe (93%) cases. Regular ventilator check was mostly done every 4 h (57%). BiPAP (47.3%) and full-face masks (45.9%) were the most used mode and interface, respectively, while pressure-regulated volume control (55.4%) and pressure control (27%) were the most used mechanical ventilation modes for COVID-19 patients. In terms of use of proning, 62% used it on IMV, while 26% reported using awake proning. Staff shortage (51.4%), personal protective equipment (PPE) shortage (51.4%), increased workload (45.9%), inadequate training (43.2%) and lack of available protocols and policies (37.8%) were the main barriers.

Conclusion:

Ventilatory support management of COVID-19 in Saudi Arabia was inconsistent with the global practice, lacked uniformity, and there was limited use of standard protocols/treatment guidelines. Shortage of staff and PPE, increased workload and insufficient training were the most prevalent barriers.

The use of non- invasive ventilation in asthma exacerbation - a two year retrospective analysis of outcomes

Background: The use of Non-Invasive Ventilation (NIV) in acute asthma exacerbation remains controversial. Comparative data on patient characteristics that benefit from NIV in asthma exacerbation to those patients that fail NIV remains limited. Our study compares some of these patient characteristics and examines if NIV is safe and effective in carefully selected patients.

Methods: Following institutional review board approval, we extracted from the electronic medical record and conducted a retrospective chart-based review of those patients who received NIV in the emergency room for a diagnosis of asthma exacerbation from January 2017 to December 2018.

Results and Conclusion: The rate of failure of NIV overall was low, at 9.17%, with younger patients more likely to fail NIV (P = 0.03) and need invasive mechanical ventilation. Surprisingly, baseline asthma severity did not impact NIV failure rate, and neither did body mass index, smoking history, and a host of clinical characteristics. Understandably, the length of stay was significantly longer in the group of patients that failed NIV. There were no adverse events, such as an increased rate of barotrauma events in either group. In conclusion, this study contributes to the growing body of evidence that NIV is a safe and effective adjunct to routine care in the management of patients with asthma exacerbation.

Predictors of Successful Weaning from Noninvasive Ventilation in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Single-Center Retrospective Cohort Study

Purpose

Noninvasive ventilation (NIV) is often required for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and it can significantly reduce the need for endotracheal intubation. Currently, there is no standard method for predicting successful weaning from NIV. Therefore, we aimed to evaluate whether a weaning index can predict NIV outcomes of patients with AECOPD.

Methods

This study was conducted at a single academic public hospital in northern Taiwan from February 2019 to January 2021. Patients with AECOPD admitted to the hospital with respiratory failure who were treated with NIV were included in the study. Univariate and multivariate logistic regression analyses were used to identify independent predictors of successful weaning from NIV. Receiver operating characteristic curve methodology was used to assess the predictive capacity.

Results

A total of 85 patients were enrolled, 65.9% of whom were successfully weaned from NIV. The patients had a mean age of 75.8 years and were mostly men (89.4%). The rapid shallow breathing index (RSBI) (P < 0.001), maximum inspiratory pressure (P = 0.014), and maximum expiratory pressure (P = 0.004) of the successful group were significant while preparing to wean. The area under the receiver operating characteristic curve for the RSBI was 0.804, which was considered excellent discrimination.

Conclusion

The RSBI predicted successful weaning from NIV in patients with AECOPD with hypercapnic respiratory failure. This index may be useful for selecting patients with AECOPD that are suitable for NIV weaning.

Determinants of usage and non-adherence to noninvasive ventilation in children and adults with Duchenne muscular dystrophy

STUDY OBJECTIVES

Duchenne muscular dystrophy (DMD) is a neuromuscular disorder that leads to chronic respiratory insufficiency and failure. Use of home noninvasive ventilation (NIV) has been linked to improved outcomes including reduced mortality. Despite the importance of NIV, factors promoting optimal NIV usage and determinants of non-adherence have not been rigorously examined. Moreover, given that respiratory issues in DMD span between childhood and adulthood, examination across a broad age group is needed. The objectives of this study were to (1) evaluate NIV usage across a broad spectrum of DMD patients including both children and adults; and (2) identify biological and socioeconomic determinants of NIV usage and NIV non-adherence.

METHODS

We performed a retrospective review of all DMD patients from Feb 2016 to Feb 2020 who underwent evaluation at associated pediatric and adult neuromuscular disease clinics. NIV use was determined objectively from device downloads. A priori, we defined non-adherence as <4 hours use per night, quantified as the percentage of nights below this threshold across a 30-day period within 6 months of a clinic visit. We also assessed the average hours of NIV usage over this time period. Predictors examined included demographics, social determinants, and pulmonary function.

RESULTS

33 patients with DMD were identified, 29 (87%) of whom were using NIV (13 age < 21 years). Mean age was 22.9±6.6 years (range 13-39 years), BMI was 23.4±10.4 kg/m², and seated forced vital capacity (FVC) was 23%±18% predicted. Mean nightly NIV usage was 7.4±3.8 hours and mean percentage of non-adherent nights was 13%±30%. In univariable analysis, age did not predict use. Those with lower FVC had higher NIV usage hours (p=0.01) and a trend toward less non-adherence (p=0.06). Higher estimated household income demonstrated a trend towards increased usage hours and less non-adherence (both p=0.08). Multivariable analysis found increased usage hours were predicted best by higher income, higher IPAP, and higher bicarbonate. Non-adherence was higher in those with lower income or higher FVC.

CONCLUSIONS

In this cohort of adult and pediatric DMD patients, most individuals were using NIV. While usage hours were higher with lower lung function, substantial variability remains unexplained by examined factors. Non-adherence was observed in some individuals, including those with advanced disease. Further investigations should focus on evaluating patient-oriented outcomes in order to define optimal NIV usage across the spectrum of disease, and determine strategies to counteract issues with non-adherence.

The application of non-invasive and invasive mechanical ventilation in the first episode of acute respiratory failure

Acute respiratory failure (RF) is a life-threatening syndrome. This study investigated the application of two major clinical strategies, non-invasive mechanical ventilation (NIV) and invasive mechanical ventilation (IMV), in the first episode of acute RF. Data from the longitudinal health insurance database, which included 1,000,000 insured citizens, were used. The NIV group consisted of 1201 patients and the IMV group consisted of 16,072 patients. Chi-square test and t test were applied to determine the differences in categorical and continuous variables. Further analysis was performed by using univariate and multivariable logistic regression and Poisson regression. There was a significant increase of 733% in the number of NIV users from 2000 to 2012. NIV use was frequently observed in old-age persons (aOR 3.99, 95% CI 3.06-5.21 for those aged ≥ 80 years), women (aOR 1.33, 95% CI 1.18-1.50), patients admitted to a high-level hospital (aOR 1.95, 95% CI 1.63-2.34 for those admitted to a medical center), and patients with a higher Charlson comorbidity index (CCI, aOR 1.38-1.66 for those CCI ≥ 2). In addition, patients with chronic pulmonary disease, cancer, and congestive heart failure were predominant in NIV users and were significantly associated with NIV use. Overall, the use of NIV has markedly increased over the past few years. Persons of advanced age, women, patients admitted to a high-level hospital, and patients with multiple comorbidities were associated with more frequent NIV use. Chronic pulmonary disease, cancer, and congestive heart failure were most important comorbidities for NIV use.

Trends in Noninvasive and Invasive Mechanical Ventilation Among Medicare Beneficiaries at the End of Life

Importance

End-of-life care is costly, and decedents often experience overtreatment or low-quality care. Noninvasive ventilation (NIV) may be a palliative approach to avoid invasive mechanical ventilation (IMV) among select patients who are hospitalized at the end of life.

Objective

To examine the trends in NIV and IMV use among decedents with a hospitalization in the last 30 days of life.

Design, Setting, and Participants

This population-based cohort study used a 20% random sample of Medicare fee-for-service beneficiaries who had an acute care hospitalization in the last 30 days of life and died between January 1, 2000, and December 31, 2017. Sociodemographic, diagnosis, and comorbidity data were obtained from Medicare claims data. Data analysis was performed from September 2019 to July 2020.

Exposures

Use of NIV or IMV.

Main Outcomes and Measures

Validated International Classification of Diseases, Ninth Revision, Clinical Modification or International Statistical Classification of Diseases, Tenth Revision, Clinical Modification procedure codes were reviewed to identify use of NIV, IMV, both NIV and IMV, or none. Four subcohorts of Medicare beneficiaries were identified using primary admitting diagnosis codes (chronic obstructive pulmonary disease [COPD], congested heart failure [CHF], cancer, and dementia). Measures of end-of-life care included in-hospital death (acute care setting), hospice enrollment at death, and hospice enrollment in the last 3 days of life. Random-effects logistic regression examined NIV and IMV use adjusted for sociodemographic characteristics, admitting diagnosis, and comorbidities.

Results

A total of 2 470 435 Medicare beneficiaries (1 353 798 women [54.8%]; mean [SD] age, 82.2 [8.2] years) were hospitalized within 30 days of death. Compared with 2000, the adjusted odds ratio (AOR) for the increase in NIV use was 2.63 (95% CI, 2.46-2.82; % receipt: 0.8% vs 2.0%) for 2005 and 11.84 (95% CI, 11.11-12.61; % receipt: 0.8% vs 7.1%) for 2017. Compared with 2000, the AOR for the increase in IMV use was 1.04 (95% CI, 1.02-1.06; % receipt: 15.0% vs 15.2%) for 2005 and 1.63 (95% CI, 1.59-1.66; % receipt: 15.0% vs 18.2%) for 2017. In subanalyses comparing 2017 with 2000, similar trends found increased NIV among patients with CHF (% receipt: 1.4% vs 14.2%; AOR, 14.14 [95% CI, 11.77-16.98]) and COPD (% receipt: 2.7% vs 14.5%; AOR, 8.22 [95% CI, 6.42-10.52]), with reciprocal stabilization in IMV use among patients with CHF (% receipt: 11.1% vs 7.8%; AOR, 1.07 [95% CI, 0.95-1.19]) and COPD (% receipt: 17.4% vs 13.2%; AOR, 1.03 [95% CI, 0.88-1.21]). The AOR for increased NIV use was 10.82 (95% CI, 8.16-14.34; % receipt: 0.4% vs 3.5%) among decedents with cancer and 9.62 (95% CI, 7.61-12.15; % receipt: 0.6% vs 5.2%) among decedents with dementia. The AOR for increased IMV use was 1.40 (95% CI, 1.26-1.55; % receipt: 6.2% vs 7.6%) among decedents with cancer and 1.28 (95% CI, 1.17-1.41; % receipt: 5.7% vs 6.2%) among decedents with dementia. Among decedents with NIV vs IMV use, lower rates of in-hospital death (50.3% [95% CI, 49.3%-51.3%] vs 76.7% [95% CI, 75.9%-77.5%]) and hospice enrollment in the last 3 days of life (57.7% [95% CI, 56.2%-59.3%] vs 63.0% [95% CI, 60.9%-65.1%]) were observed along with higher rates of hospice enrollment (41.3% [95% CI, 40.4%-42.3%] vs 20.0% [95% CI, 19.2%-20.7%]).

Conclusions and Relevance

This study found that the use of NIV rapidly increased from 2000 through 2017 among Medicare beneficiaries at the end of life, especially among persons with cancer and dementia. The findings suggest that trials to evaluate the outcomes of NIV are warranted to inform discussions about the goals of this therapy between clinicians and patients and their health care proxies.

A Novel Mainstream Capnometer System for Non-invasive Positive Pressure Ventilation

Capnometry is a method to measure carbon dioxide (CO₂) in exhaled gas and it has been used to monitor patient respiratory status. CO₂ monitoring is also used for patients receiving non-invasive positive pressure ventilation (NPPV) therapy during mechanical ventilation. Ventilators actively dilute exhaled gas during non-invasive ventilation. In order to accurately measure end-tidal CO₂, an adequate amount of expired gas needs to be filled in a CO₂ measurement cell before expiratory positive airway pressure (EPAP) gas from the ventilator arrives to the cell. This is the reason why it is difficult to measure CO₂ stably during non-invasive ventilation using the conventional CO₂ measurement method. Therefore, we developed NPPV cap-ONE mask, which accurately measures CO₂ in exhaled gas during non-invasive ventilation. In this study, we evaluated the basic performance of the NPPV cap-ONE mask system. The NPPV cap-ONE mask system could accurately measure CO₂ in exhaled gas comparing to the conventional device in this study.

Risk Factors for and Outcomes Associated With Peri-Intubation Hypoxemia: A Multicenter Prospective Cohort Study

BACKGROUND

Little is known about hypoxemia surrounding endotracheal intubation in the critically ill. Thus, we sought to identify risk factors associated with peri-intubation hypoxemia and its effects' on the critically ill.

METHODS

Data from a multicenter, prospective, cohort study enrolling 1,033 critically ill adults who underwent endotracheal intubation across 16 medical/surgical ICUs in the United States from July 2015-January 2017 were used to identify risk factors associated with peri-intubation hypoxemia and its effects on patient outcomes. We defined hypoxemia as any pulse oximetry ≤ 88% during and up to 30 minutes following endotracheal intubation.

RESULTS

In the full analysis (n = 1,033), 123 (11.9%) patients experienced the primary outcome. Five risk factors independently associated with our outcome were identified on multiple logistic regression: cardiac related reason for endotracheal intubation (OR 1.67, [95% CI 1.04, 2.69]); pre-intubation noninvasive ventilation (OR 1.66, [95% CI 1.09, 2.54]); emergency intubation (OR 1.65, [95% CI 1.06, 2.55]); moderate-severe difficult bag-mask ventilation (OR 2.68, [95% CI 1.72, 4.19]); and crystalloid administration within the preceding 24 hours (OR 1.24, [95% CI 1.07, 1.45]; per liter up to 4 liters). Higher baseline S_pO₂ was found to be protective (OR 0.93, [95% CI 0.91, 0.96]; per percent up to 97%). Consistent results were seen in a separate analysis on only stable patients (n = 921, 93 [10.1%]) (those without baseline hypoxemia ≤ 88%). Peri-intubation hypoxemia was associated with in-hospital mortality (OR 2.40, [95% CI 1.33, 4.31]; stable patients: OR 2.67, [95% CI 1.38, 5.17]) but not ICU length of stay (point estimate 0.9 days, [95% CI -1.0, 2.8 days]; stable patients: point estimate 1.5 days, [95% CI -0.4, 3.4 days]) after adjusting for age, body mass index, illness severity, airway related reason for intubation (i.e., acute respiratory failure), and baseline S_PO₂.

CONCLUSIONS

Patients with pre-existing noninvasive ventilation and volume loading who were intubated emergently in the setting of hemodynamic compromise with bag-mask ventilation described as moderate-severe were at increased risk for peri-intubation hypoxemia. Higher baseline oxygenation was found to be protective against peri-intubation hypoxemia. Peri-intubation hypoxemia was associated with in-hospital mortality but not ICU length of stay.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02508948 and Registered Report Identifier: RR2-10.2196/11101.

Noninvasive Ventilation for Critically Ill Subjects With Acute Respiratory Failure in the Emergency Department

BACKGROUND

We aimed to investigate the association between noninvasive ventilation (NIV) initiated in the emergency department and patient outcomes for those requiring invasive mechanical ventilation so that we could understand the effect of extended NIV use (ie, > 4 h) prior to invasive mechanical ventilation on patient outcomes.

METHODS

We conducted a retrospective single-center cohort study at an academic tertiary care hospital center. All emergency department patients with acute respiratory failure requiring invasive mechanical ventilation and admission to the ICU within 48 h of initial presentation over a 24-month period were included.

RESULTS

Subject characteristics, ventilator parameters, and clinical course were captured via electronic query, respiratory billing data, and standardized chart abstraction. A total of 431 subjects with acute respiratory failure requiring invasive mechanical ventilation within 48 h of arrival were identified, of whom 115 (26.7%) were exposed to NIV prior to invasive mechanical ventilation, with a median duration of 4 h (interquartile range 1.9-9.3). Based on a multivariable model controlling for covariates, any NIV exposure prior to invasive mechanical ventilation was not associated with an increased odds of persistent organ dysfunction or death. However, in the subset of subjects exposed to NIV, extended NIV use (ie, > 4 h) prior to invasive mechanical ventilation was associated with increased odds of persistent organ dysfunction or death (odds ratio 4.11, 95% CI 1.51-11.19). Extended NIV use was also associated with increased odds of in-hospital mortality (odds ratio 4.02, 95% CI 1.51-10.74).

CONCLUSIONS

Although any exposure to NIV prior to invasive mechanical ventilation did not appear to affect morbidity and mortality, extended NIV use prior to invasive mechanical ventilation was associated with worse patient outcomes, suggesting a need for additional study to better understand the ramifications of duration of NIV use prior to failure on outcomes. Given this early timeframe for intervention, future studies should be collaborations between the emergency department and ICU.

Primary Acute Neuromuscular Respiratory Failure

Neurologists are often called to evaluate patients with both defined and undiagnosed neuromuscular disorders when respiratory failure develops to determine if there is a neuromuscular cause. Being able to confidently diagnose neuromuscular respiratory failure and intervene appropriately is imperative, as early intervention and determination of the cause have survival implications. Outcomes are poor when the cause of neuromuscular weakness and resultant respiratory failure cannot be identified. This review discusses the clinical recognition of primary neuromuscular respiratory failure, its pathophysiology, diagnostic evaluation, and management, focusing on management of respiratory failure in the setting of Guillain-Barré syndrome and myasthenic crisis.

Outcomes of Noninvasive and Invasive Ventilation in Patients Hospitalized with Asthma Exacerbation

RATIONALE

Little is known about the effectiveness of noninvasive ventilation for patients hospitalized with asthma exacerbation.

OBJECTIVES

To assess clinical outcomes of noninvasive (NIV) and invasive mechanical ventilation (IMV) and examine predictors for NIV use in patients hospitalized with asthma.

METHODS

This was a retrospective cohort study at 97 U.S. hospitals using an electronic medical record database. We developed a hierarchical regression model to identify factors associated with the choice of initial ventilation and used the Laboratory Acute Physiological Score to adjust for differences in the severity of illness. We assessed the outcomes of patients treated with initial NIV or IMV in a propensity-matched cohort.

MEASUREMENTS AND MAIN RESULTS

Among 13,930 subjects, 73% were women and 54% were white. The median age was 53 years. Overall, 1,254 patients (9%) required ventilatory support (NIV or IMV). NIV was the initial ventilation method for 556 patients (4.0%) and IMV for 668 (5.0%). Twenty-six patients (4.7% of patients treated with NIV) had to be intubated (NIV failure). The in-hospital mortality was 0.2, 2.3, 14.5, and 15.4%, and the median length of stay was 2.9, 4.1, 6.7, and 10.9 days among those not ventilated, ventilated with NIV, ventilated with IMV, and with NIV failure, respectively. Older patients were more likely to receive NIV (odds ratio, 1.06 per 5 yr; 95% confidence interval [CI], 1.01-1.11), whereas those with higher acuity (Laboratory Acute Physiological Score per 5 units: odds ratio, 0.85; 95% CI, 0.82-0.88) and those with concomitant pneumonia were less likely to receive NIV. In a propensity-matched sample, NIV was associated with a lower inpatient risk of dying (risk ratio, 0.12; 95% CI, 0.03-0.51) and shorter lengths of stay (4.3 d less; 95% CI, 2.9-5.8) than IMV.

CONCLUSIONS

Among patients hospitalized with asthma exacerbation and requiring ventilatory support (NIV or IMV), more than 40% received NIV. Although patients successfully treated with NIV appear to have better outcomes than those treated with IMV, the low rate of NIV failure suggests that NIV was being used selectively in a lower risk group. The increased risk of mortality for patients who fail NIV highlights the need for careful monitoring to avoid possible delay in intubation.

Analysis of ineffective breathing pattern and impaired spontaneous ventilation of adults with oxygen therapy

Objective:

to analyze the manifestation of the defining characteristics of the nursing diagnoses of ineffective breathing pattern and impaired spontaneous ventilation, of the NANDA International and the defining characteristics identified in the literature for the concept of “ventilation” in adult patients hospitalized in an intensive care unit with use of oxygen therapy.

Method:

clinical diagnostic validation study, conducted with 626 patients in intensive care using oxygen therapy, in three different modalities. Multiple correspondence analysis was used to verify the discriminative capacity of the defining characteristics and latent class analysis to determine the diagnostic accuracy of them, based on the severity level defined by the ventilatory mode used.

Results:

in the multiple correspondence analysis, it was demonstrated that the majority of the defining characteristics presented low discriminative capacity and low percentage of explained variance for the two dimensions (diagnoses). Latent class models, separately adjusted for the two diagnoses, presented a worse fit, with sharing of some defining characteristics. Models adjusted by level of severity (ventilation mode) presented better fit and structure of the component defining characteristics.

Conclusion:

clinical evidence obtained in the present study seems to demonstrate that the set of defining characteristics of the two nursing diagnoses studied fit better in a single construct.

Outcomes and predictors of failure of non-invasive ventilation in patients with community acquired pneumonia in the ED

OBJECTIVE

We set out to describe the use and analyze the predictors of non-invasive ventilation failure in patients with community-acquired pneumonia who receive non-invasive ventilation as first line ventilatory therapy in the emergency department.

METHODS

A retrospective cohort study was conducted among consecutive patients with community acquired pneumonia requiring ventilator support presenting to two tertiary care university-affiliated emergency departments. Multivariable logistic regression analysis was used to determine predictors of non-invasive ventilation failure at initiation of non-invasive ventilation and at two hours of non-invasive ventilation use; RESULT: After excluding patients with a do not resuscitate order status, 163 (74.8%) patients with community acquired pneumonia were initially treated with non-invasive ventilation on initial presentation to the emergency department. Non-invasive ventilation failure occurred in 50% of patients and was found to be associated with the absence of chronic obstructive airway disease, APACHE II score, the need for hemodynamic support and the number of CXR quadrants involved. Two-hour physiological parameters associated with non-invasive ventilation failure included higher respiratory rate, lower serum pH and the ongoing need of hemodynamic support.

CONCLUSION

In conclusion, the use of non-invasive ventilation to support patients presenting to the emergency department with respiratory failure and community acquired pneumonia is common and is associated with a significant failure rate. Hemodynamic support is a strong predictor of failure. The selection of the appropriate patient and monitoring of physiological parameters while on NIV is crucial to ensure successful treatment.

What prevents critically ill patients with respiratory failure from using non-invasive positive pressure ventilation: A mixed-methods study

AIM

To identify the factors that prevent patients in respiratory failure from using noninvasive positive pressure ventilation (NPPV). The following were evaluated: (i) the patients who converted from NPPV to endotracheal intubation; and (ii) the patients who abandoned NPPV.

METHODS

Patients were interviewed regarding their experience with NPPV. Next, the factors that prevented the continuation of NPPV were identified and those data were collected retrospectively from medical records. The participants included adult patients in intensive care who were undergoing NPPV. The data from the interviews of nine participants were analyzed by using content analysis. Data that were collected from the medical records of 126 participants contributed to the identification of the characteristics that affected the implementation of NPPV. The factors were entered into a model by using logistic regression and decision-tree analysis.

RESULTS

An interview content analysis revealed eight aspects of the patients' experiences. In the medical record analysis, the specific factors that were associated with the conversion to intubation were the Acute Physiology and Chronic Health Evaluation II scores, breathing becoming easier, arterial oxygen partial pressure to fractional inspired oxygen ratio, and realizing the necessity of NPPV. The factors that were associated with the abandonment of NPPV included sleep loss, delirium, discomfort, and the arterial oxygen partial pressure to fractional inspired oxygen ratio. Realizing the necessity of NPPV was not statistically significant. With regard to the decision-tree analysis, the factors that were selected were similar to those that were selected in the factor analysis.

CONCLUSION

In the initial stage of NPPV, focusing on dyspnea, sleep loss, discomfort, delirium, and the realization of the necessity of NPPV were critical in deciding on continuing this intervention or the early conversion to intubation.

Noninvasive Ventilation in Patients With Hematologic Malignancy

INTRODUCTION

Noninvasive ventilation (NIV) is commonly used as first-line therapy for immunocompromised patients with acute respiratory failure. However, it may not be appropriate for all patients, as failure of NIV and delayed endotracheal intubation (ETI) may increase mortality. We report our center's experience and outcomes for patients with active hematologic malignancy (HM) treated with NIV.

METHODS

We conducted a retrospective study of consecutive patients with HM who were admitted to the intensive care unit (ICU) of Mount Sinai Hospital for acute respiratory failure between January 1, 2010, and May 31, 2015, and were initially treated with NIV. We compared the characteristics of patients who were successfully treated with NIV and avoided intubation and those who failed NIV.

RESULTS

Seventy-nine patients (mean age 56 ± 14 years, mean Acute Physiology and Chronic Health Evaluation II score 27 ± 5) with HM were treated with NIV for acute respiratory failure. The etiology of respiratory failure was multifactorial in 31 (39%) patients, with features of pneumonia in 61 (77%) patients, severe sepsis or septic shock in 33 (42%) patients, and pulmonary edema in 24 (30%) patients. The majority of patients were admitted with acute leukemia (n = 60, 76%), 8 (10%) with lymphoma, and 11 (14%) with chronic leukemia, multiple myeloma, or myelodysplastic syndrome. Of the 79 patients treated with NIV, 44 (56%) failed NIV and required ETI, 7 (9%) had a do-not-intubate (DNI) order and died, and 28 (35%) avoided ETI. Compared with patients who avoided ETI, those who failed NIV or had a DNI order and died were more likely to have acute leukemia (84% vs 61%; P = .02) and at baseline had higher Paco2 (39 vs 30; P = .038), higher fraction of inspired oxygen (Fio2) requirements (0.6 vs 0.4; P = .002), and more vasopressor use (31% vs 11%; P = .059). The ICU mortality was 42%; 3-month mortality was 57% overall and was significantly lower in the NIV success patients compared with the NIV failure group (21% vs 74%; P < .001).

CONCLUSION

Two-thirds of patients with HM and respiratory failure failed NIV and required ETI, and had high subsequent mortality. Patients who failed NIV had higher Paco2, higher Fio2, and a trend toward more vasopressor use.

Noninvasive ventilation for neuromuscular respiratory failure: when to use and when to avoid

PURPOSE OF REVIEW

Neuromuscular respiratory failure can occur from a variety of diseases, both acute and chronic with acute exacerbation. There is often a misunderstanding about how the nature of the neuromuscular disease should affect the decision on how to ventilate the patient. This review provides an update on the value and relative contraindications for the use of noninvasive ventilation in patients with various causes of primary neuromuscular respiratory failure.

RECENT FINDINGS

Myasthenic crisis represents the paradigmatic example of the neuromuscular condition that can be best treated with noninvasive ventilation. Timely use of noninvasive ventilation can substantially reduce the duration of ventilatory assistance in these patients. Noninvasive ventilation can also be very helpful after extubation in patients recovering from an acute cause of neuromuscular respiratory failure who have persistent weakness. Noninvasive ventilation can improve quality of survival in patients with advanced motor neuron disorder (such as amyotrophic lateral sclerosis) and muscular dystrophies, and can avoid intubation when these patients present to the hospital with acute respiratory failure. Attempting noninvasive ventilation is not only typically unsuccessful in patients with Guillain-Barre syndrome, but can also be dangerous in these cases.

SUMMARY

Noninvasive ventilation can be very effective to treat acute respiratory failure caused by myasthenia gravis and to prevent reintubation in other neuromuscular patients, but should be used cautiously for other indications, particularly Guillain-Barre syndrome.

Management of critical illness with non-invasive ventilation by an Australian HEMS

BACKGROUND

Non-invasive ventilation (NIV) therapy is widely used for the management of acute respiratory failure. The objective of this study was to investigate the current use of NIV during interhospital retrievals in an Australian physician-led aeromedical service.

METHODS

We reviewed patients receiving NIV during interhospital retrieval at the Greater Sydney Area Helicopter Medical Services (GSA-HEMS) over a 14-month period. The main objectives were to describe the number of retrievals using NIV, the need for intubation in NIV patients and the effect of the therapy on mission duration.

RESULTS

Over the study period, 3018 missions were reported; 106 cases (3.51%) involved administration of NIV therapy during the retrieval. The most common indication for NIV was pneumonia (34.0%). 86/106 patients received a successful trial of NIV therapy prior to interhospital transfer. 58 patients were transferred on NIV, while 28 patients had NIV removed during transport. None of these 86 patients required intubation or died, although 17/86 ultimately required intubation within 24 hours at the receiving centre. 20/106 patients required intubation at the referring hospital after a failed trial of NIV therapy. NIV was successfully used in all available transport platforms including rotary wing. Patients receiving NIV were found to have prolonged mission durations compared with other GSA-HEMS patients (222.5 vs 193 min). This increase in mission duration was largely attributable to NIV failure, resulting in a need for Rapid Sequence Intubation at the referring hospital.

CONCLUSIONS

With careful patient selection, the use of interhospital NIV is feasible and appears to be safe in a retrieval system with care provided by a critical care physician.

Hospital Noninvasive Ventilation Case Volume and Outcomes of Acute Exacerbations of Chronic Obstructive Pulmonary Disease

RATIONALE

Higher hospital case volume may produce local expertise ("practice makes perfect"), resulting in better patient outcomes. Associations between hospital noninvasive ventilation (NIV) case volume and outcomes for patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) are unclear.

OBJECTIVES

To determine associations between total hospital NIV case volume for all indications and NIV failure and hospital mortality among patients with acute exacerbations of COPD.

METHODS

Using the 2011 California State Inpatient Database and multivariable hierarchical logistic regression, we calculated hospital-level risk-adjusted rates for NIV failure (progression from NIV to invasive mechanical ventilation) and hospital mortality among patients with acute exacerbations of COPD.

MEASUREMENTS AND MAIN RESULTS

We identified 37,516 hospitalizations for acute exacerbations of COPD in 252 California hospitals in 2011. Total hospital NIV use for all indications ranged from 2 to 565 cases (median, 64; interquartile range, 96). Hospital NIV failure rates for acute exacerbations of COPD ranged from 3.7 to 31.3% (median, 8.5%; interquartile range, 4.2). At the hospital level, higher total hospital NIV case volume was weakly associated with higher hospital NIV failure rates for acute exacerbations of COPD (r = 0.13; P = 0.03). Higher hospital NIV failure rates were weakly associated with higher hospital mortality rates for acute exacerbations of COPD (r = 0.15; P = 0.02), but higher total hospital NIV case volume was not associated with hospital mortality for exacerbations of COPD (r = -0.11; P = 0.08). At the patient level, patients admitted to high-NIV versus low-NIV case-volume hospitals had greater odds of NIV failure (quartile 4 vs. quartile 1 adjusted odds ratio [aOR], 1.95; 95% confidence interval [CI], 1.12-3.40). Compared with initial treatment with invasive mechanical ventilation, NIV failure was associated with higher odds of death (aOR, 1.81; 95% CI, 1.35-2.44). However, admission to high-NIV versus low-NIV case-volume hospitals was not significantly associated with patient in-hospital mortality (quartile 4 vs. quartile 1 aOR, 0.76; 95% CI, 0.57-1.02).

CONCLUSIONS

Despite strong evidence for use of NIV in the management of acute exacerbations of COPD, we observed no significant mortality benefit and higher rates of NIV failure in high-NIV case-volume hospitals. Further investigation of patient selection and hospital factors associated with NIV failure is needed to maximize favorable patient outcomes associated with use of NIV for acute exacerbations of COPD.

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.

A new horizon for the use of non-invasive ventilation in patients with acute respiratory distress syndrome

Non-invasive ventilation (NIV) has assumed an important role in the management of acute respiratory failure (ARF). NIV, compared with standard medical therapy, improves survival and reduces complications in selected patients with ARF. NIV represents the first-line intervention for some forms of ARF, such as chronic obstructive pulmonary disease (COPD) exacerbations and acute cardiogenic pulmonary edema. The use of NIV is also well supported for immunocompromised patients who are at high risk for infectious complications from endotracheal intubation. Selection of appropriate patients is crucial for optimizing NIV success rates. Appropriate ventilator settings, a well-fitting and comfortable interface, and a team skilled and experienced in managing NIV are key components to its success. In a recent issue of the Journal of the American Medical Association, Patel et al. reported the results of their single-center trial of 83 patients with acute respiratory distress syndrome (ARDS) who were randomly assigned to NIV delivered via a helmet or face mask. Patients assigned to the helmet group exhibited a significantly lower intubation rate and were more likely to survive through 90 days. This perspective reviews the findings of this trial in the context of current clinical practice and in light of data from the literature focused on the potential reasons for success of NIV delivered through a helmet compared to face mask. The implications for early management of patients with ARDS are likewise discussed.

Work of breathing using different interfaces in spontaneous positive pressure ventilation: helmet, face-mask, and endotracheal tube

PURPOSE

Noninvasive positive pressure ventilation (NPPV) using a helmet is expected to cause inspiratory trigger delay due to the large collapsible and compliant chamber. We compared the work of breathing (WOB) of NPPV using a helmet or a full face-mask with that of invasive ventilation by tracheal intubation.

METHODS

We used a lung model capable of simulating spontaneous breathing (LUNGOO; Air Water Inc., Japan). LUNGOO was set at compliance (C) = 50 mL/cmH2O and resistance (R) = 5 cmH2O/L/s for normal lung simulation, C = 20 mL/cmH2O and R = 5 cmH2O/L/s for restrictive lung, and C = 50 mL/cmH2O and R = 20 cmH2O/L/s for obstructive lung. Muscle pressure was fixed at 25 cmH2O and respiratory rate at 20 bpm. Pressure support ventilation and continuous positive airway pressure were performed with each interface placed on a dummy head made of reinforced plastic that was connected to LUNGOO. We tested the inspiratory WOB difference between the interfaces with various combinations of ventilator settings (positive end-expiratory pressure 5 cmH2O; pressure support 0, 5, and 10 cmH2O).

RESULTS

In the normal lung and restrictive lung models, WOB decreased more with the face-mask than the helmet, especially when accompanied by the level of pressure support. In the obstructive lung model, WOB with the helmet decreased compared with the other two interfaces. In the mixed lung model, there were no significant differences in WOB between the three interfaces.

CONCLUSION

NPPV using a helmet is more effective than the other interfaces for WOB in obstructive lung disease.

Anesthetic management in atrial fibrillation ablation procedure: Adding non-invasive ventilation to deep sedation

Anesthetic management of patients undergoing pulmonary vein isolation for atrial fibrillation has specific requirements. The feasibility of non-invasive ventilation (NIV) added to deep sedation procedure was evaluated.

Seventy-two patients who underwent ablation procedure were retrospectively revised, performed with (57%) or without (43%) application of NIV (Respironic^® latex-free total face mask connected to Garbin ventilator-Linde Inc.) during deep sedation (Midazolam 0.01–0.02 mg/kg, fentanyl 2.5–5 μg/kg and propofol: bolus dose 1–1.5 mg/kg, maintenance 2–4 mg/kg/h).

In the two groups (NIV vs deep sedation), differences were detected in intraprocedural (pH 7.37 ± 0.05 vs 7.32 ± 0.05, p = 0.001; PaO₂ 117.10 ± 27.25 vs 148.17 ± 45.29, p = 0.004; PaCO₂ 43.37 ± 6.91 vs 49.33 ± 7.34, p = 0.002) and in percentage variation with respect to basal values (pH −0.52 ± 0.83 vs −1.44 ± 0.87, p = 0.002; PaCO₂ 7.21 ± 15.55 vs 34.91 ± 25.76, p = 0.001) of arterial blood gas parameters. Two episodes of respiratory complications, treated with application of NIV, were reported in deep sedation procedure. Endotracheal intubation was not necessary in any case. Adverse events related to electrophysiological procedures and recurrence of atrial fibrillation were recorded, respectively, in 36% and 29% of cases.

NIV proved to be feasible in this context and maintained better respiratory homeostasis and better arterial blood gas balance when added to deep sedation.

Management Issues in Intensive Care Units for Infants and Children with Heart Disease

Admission of infants and children with cardiac disease to the neonatal (NICU) and pediatric ICU (PICU) is ever increasing in India (30-50 % of all admissions). The commonest indication for admission to the NICU or PICU is acute deterioration of cardiac disease. This includes: acute heart failure, hypercyanotic spells, arrhythmias, pericardial tamponade and sick cardiac neonates who need urgent intervention. Other increasingly frequent indications for ICU admission include heart failure with concomitant chest infection and impending respiratory failure and, severe cyanotic heart disease with various stroke syndromes. It is thus essential that a pediatrician be comfortable with the ICU management of such children and that low cost ICU modalities be utilized in order to reach out to as many children as feasible. It is heartening that there is renewed interest in inexpensive therapies like noninvasive ventilation and therapeutic hypothermia.

Mortality Prediction in Patients Undergoing Non-Invasive Ventilation in Intermediate Care

Background

Intermediate Care Units (ImCU) have become an alternative scenario to perform Non-Invasive Ventilation (NIV). The limited number of prognostic studies in this population support the need of mortality prediction evaluation in this context.

Objective

The objective of this study is to analyze the performance of Simplified Acute Physiology Score (SAPS) II and 3 in patients undergoing NIV in an ImCU. Additionally, we searched for new variables that could be useful to customize these scores, in order to improve mortality prediction.

Design

Cohort study with prospectively collected data from all patients admitted to a single center ImCU who received NIV. The SAPS II and 3 scores with their respective predicted mortality rates were calculated. Discrimination and calibration were evaluated by calculating the area under the receiver operating characteristic curve (AUC) and with the Hosmer-Lemeshow goodness of fit test for the models, respectively. Binary logistic regression was used to identify new variables to customize the scores for mortality prediction in this setting.

Patients

The study included 241 patients consecutively admitted to an ImCU staffed by hospitalists from April 2006 to December 2013.

Key Results

The observed in-hospital mortality was 32.4% resulting in a Standardized Mortality Ratio (SMR) of 1.35 for SAPS II and 0.68 for SAPS 3. Mortality discrimination based on the AUC was 0.73 for SAPS II and 0.69 for SAPS 3. Customized models including immunosuppression, chronic obstructive pulmonary disease (COPD), acute pulmonary edema (APE), lactic acid, pCO2 and haemoglobin levels showed better discrimination than old scores with similar calibration power.

Conclusions

These results suggest that SAPS II and 3 should be customized with additional patient-risk factors to improve mortality prediction in patients undergoing NIV in intermediate care.

Mechanical ventilation for severe asthma

Acute exacerbations of asthma can lead to respiratory failure requiring ventilatory assistance. Noninvasive ventilation may prevent the need for endotracheal intubation in selected patients. For patients who are intubated and undergo mechanical ventilation, a strategy that prioritizes avoidance of ventilator-related complications over correction of hypercapnia was first proposed 30 years ago and has become the preferred approach. Excessive pulmonary hyperinflation is a major cause of hypotension and barotrauma. An appreciation of the key determinants of hyperinflation is essential to rational ventilator management. Standard therapy for patients with asthma undergoing mechanical ventilation consists of inhaled bronchodilators, corticosteroids, and drugs used to facilitate controlled hypoventilation. Nonconventional interventions such as heliox, general anesthesia, bronchoscopy, and extracorporeal life support have also been advocated for patients with fulminant asthma but are rarely necessary. Immediate mortality for patients who are mechanically ventilated for acute severe asthma is very low and is often associated with out-of-hospital cardiorespiratory arrest before intubation. However, patients who have been intubated for severe asthma are at increased risk for death from subsequent exacerbations and must be managed accordingly in the outpatient setting.

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.

Humidification on Ventilated Patients: Heated Humidifications or Heat and Moisture Exchangers?

The normal physiology of conditioning of inspired gases is altered when the patient requires an artificial airway access and an invasive mechanical ventilation (IMV). The endotracheal tube (ETT) removes the natural mechanisms of filtration, humidification and warming of inspired air. Despite the noninvasive ventilation (NIMV) in the upper airways, humidification of inspired gas may not be optimal mainly due to the high flow that is being created by the leakage compensation, among other aspects. Any moisture and heating deficit is compensated by the large airways of the tracheobronchial tree, these are poorly suited for this task, which alters mucociliary function, quality of secretions, and homeostasis gas exchange system. To avoid the occurrence of these events, external devices that provide humidification, heating and filtration have been developed, with different degrees of evidence that support their use.

Pathophysiological Basis of Acute Respiratory Failure on Non-Invasive Mechanical Ventilation

Noninvasive mechanical ventilation (NIMV) was created for patients who needed noninvasive ventilator support, this procedure decreases the complications associated with the use of endotracheal intubation (ETT). The application of NIMV has acquired major relevance in the last few years in the management of acute respiratory failure (ARF), in patients with hypoxemic and hypercapnic failure. The main advantage of NIMV as compared to invasive mechanical ventilation (IMV) is that it can be used earlier outside intensive care units (ICUs). The evidence strongly supports its use in patients with COPD exacerbation, support in weaning process in chronic obstructive pulmonary disease (COPD) patients, patients with acute cardiogenic pulmonary edema (ACPE), and Immunosuppressed patients. On the other hand, there is poor evidence that supports the use of NIMV in other pathologies such as pneumonia, acute respiratory distress syndrome (ARDS), and during procedures as bronchoscopy, where its use is still controversial because the results of these studies are inconclusive against the decrease in the rate of intubation or mortality.

Evaluation of efficacy of non-invasive ventilation in Non-COPD and non-trauma patients with acute hypoxemic respiratory failure: A systematic review and meta-analysis

Non-invasive ventilation (NIV) has been widely supported in the past two decades as an effective application in avoiding the need for endotracheal intubation (ETI) and reducing associated mortality in acute hypoxemic respiratory failure (AHRF) patients. However, the efficacy of NIV in AHRF patients, non-related to chronic obstructive pulmonary disease (COPD) and trauma is still controversial in the field of medical research. This retrospective study aimed to evaluate the efficacy of NIV as an adjunctive therapy in non-COPD and non-traumatic AHRF patients. Data of 11 randomized control trials (RCTs), which were conducted between 1990 and 2010 to determine the efficacy of NIV in non-COPD and non-traumatic AHRF patients, were reviewed from the PUBMED, MEDLINE, Cochrane Library, and EMBASE databases. Parameters monitored in this study included the ETI rate, fatal complications, mortality rate of patients, and their ICU and hospital duration of stay. Overall results showed a statistically significant decrease in the rate of ETI, mortality, and fatal complications along with reduced ICU and hospital length of stay in non-COPD and non-trauma AHRF patients of various etiologies. This systematic review suggests that non-COPD and non-trauma AHRF patients can potentially benefit from NIV as compared with conventional treatment methods. Observations from various cohort studies, observational studies, and previously published literature advocate on the efficacy of NIV for treating non-COPD and non-traumatic AHRF patients. However, considering the diversity of studied populations, further studies and more specific trials on less heterogeneous AHRF patient groups are needed to focus on this aspect.

Outcomes associated with invasive and noninvasive ventilation among patients hospitalized with exacerbations of chronic obstructive pulmonary disease

IMPORTANCE

Small clinical trials have shown that noninvasive ventilation (NIV) is efficacious in reducing the need for intubation and improving short-term survival among patients with severe exacerbations of chronic obstructive pulmonary disease (COPD). Little is known, however, about the effectiveness of NIV in routine clinical practice.

OBJECTIVE

To compare the outcomes of patients with COPD treated with NIV to those treated with invasive mechanical ventilation (IMV).

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective cohort study of 25 628 patients hospitalized for exacerbation of COPD who received mechanical ventilation on the first or second hospital day at 420 US hospitals participating in the Premier Inpatient Database.

EXPOSURES

Initial ventilation strategy.

MAIN OUTCOMES AND MEASURES

In-hospital mortality, hospital-acquired pneumonia, hospital length of stay and cost, and 30-day readmission.

RESULTS

In the study population, a total of 17 978 (70%) were initially treated with NIV on hospital day 1 or 2. When compared with those initially treated with IMV, NIV-treated patients were older, had less comorbidity, and were less likely to have concomitant pneumonia present on admission. In a propensity-adjusted analysis, NIV was associated with lower risk of mortality than IMV (odds ratio [OR] 0.54; [95% CI, 0.48-0.61]). Treatment with NIV was associated with lower risk of hospital-acquired pneumonia (OR, 0.53 [95% CI, 0.44-0.64]), lower costs (ratio, 0.68 [95% CI, 0.67-0.69]), and a shorter length of stay (ratio, 0.81 [95% CI, 0.79-0.82]), but no difference in 30-day all-cause readmission (OR, 1.04 [95% CI, 0.94-1.15]) or COPD-specific readmission (OR, 1.05 [95% CI, 0.91-1.22]). Propensity matching attenuated these associations. The benefits of NIV were similar in a sample restricted to patients younger than 85 years and were attenuated among patients with higher levels of comorbidity and concomitant pneumonia. Using the hospital as an instrumental variable, the strength of association between NIV and mortality was modestly attenuated (OR, 0.66 [95% CI, 0.47-0.91]). In sensitivity analyses, the benefit of NIV was robust in the face of a strong hypothetical unmeasured confounder.

CONCLUSIONS AND RELEVANCE

In a large retrospective cohort study, patients with COPD treated with NIV at the time of hospitalization had lower inpatient mortality, shorter length of stay, and lower costs compared with those treated with IMV.

Efficacy and safety of early dexmedetomidine during noninvasive ventilation for patients with acute respiratory failure: a randomized, double-blind, placebo-controlled pilot study

BACKGROUND

Successful application of noninvasive ventilation (NIV) for acute respiratory failure (ARF) requires patient cooperation and comfort. The efficacy and safety of early IV dexmedetomidine when added to protocolized, as-needed IV midazolam and fentanyl remain unclear.

METHODS

Adults with ARF and within 8 h of starting NIV were randomized to receive IV dexmedetomidine (0.2 μg/kg/h titrated every 30 min to 0.7 μg/kg/h to maintain a Sedation-Agitation Scale [SAS] score of 3 to 4) or placebo in a double-blind fashion up to 72 h, until NIV was stopped for ≥ 2 h, or until intubation. Patients with agitation (SAS ≥ 5) or pain (visual analog scale ≥ 5 of 10 cm) 15 min after each dexmedetomidine and placebo increase could receive IV midazolam 0.5 to 1.0 mg or IV fentanyl 25 to 50 μg, respectively, at a minimum interval of every 3 h.

RESULTS

The dexmedetomidine (n = 16) and placebo (n = 17) groups were similar at baseline. Use of early dexmedetomidine did not improve NIV tolerance (score, 1 of 4; OR, 1.44; 95% CI, 0.44-4.70; P = .54) nor, vs. placebo, led to a greater median (interquartile range) percent time either tolerating NIV (99% [61%-100%] vs. 67% [40%-100%], P = .56) or remaining at the desired sedation level (SAS score = 3 or 4, 100% [86%-100%] vs. 100% [100%-100%], P = .28], or fewer intubations (P = .79). Although use of dexmedetomidine was associated with a greater duration of NIV vs placebo (37 [16-72] vs. 12 [4-22] h, P = .03), the total ventilation duration (NIV + invasive) was similar (3.3 [2-4] days vs. 3.8 [2-5] days, P = .52). More patients receiving dexmedetomidine had one or more episodes of deep sedation vs placebo (SAS ≤ 2, 25% vs. 0%, P = .04). Use of midazolam (P = .40) and episodes of either severe bradycardia (heart rate ≤ 50 beats/min, P = .18) or hypotension (systolic BP ≤ 90 mm Hg, P = .64) were similar.

CONCLUSIONS

Initiating dexmedetomidine soon after NIV initiation in patients with ARF neither improves NIV tolerance nor helps to maintain sedation at a desired goal. Randomized, multicenter trials targeting patients with initial intolerance are needed to further elucidate the role for dexmedetomidine in this population.

Use and outcomes of noninvasive positive pressure ventilation in acute care hospitals in Massachusetts

BACKGROUND

This study determined actual utilization rates and outcomes of noninvasive positive pressure ventilation (NIV) at selected hospitals that had participated in a prior survey on NIV use.

METHODS

This observational cohort study, based at eight acute care hospitals in Massachusetts, focused on all adult patients requiring ventilatory support for acute respiratory failure during predetermined time intervals.

RESULTS

Of 548 ventilator starts, 337 (61.5%) were for invasive mechanical ventilation and 211 (38.5%) were for NIV, with an overall NIV success rate of 73.9% (ie, avoidance of intubation or death while on NIV or within 48 h of discontinuation). Causal diagnoses for respiratory failure were classified as (I) acute-on-chronic lung disease (23.5%), (II) acute de novo respiratory failure (17.9%), (III) neurologic disorders (19%), (IV) cardiogenic pulmonary edema (16.8%), (V) cardiopulmonary arrest (12.2%), and (VI) others (10.6%). NIV use and success rates for each of the causal diagnoses were, respectively, (I) 76.7% and 75.8%, (II) 37.8% and 62.2%, (III) 1.9% and 100%, (IV) 68.5% and 79.4%, (V) none, and (VI) 17.2% and 60%. Hospital mortality rate was higher in patients with invasive mechanical ventilation than in patients with NIV (30.3% vs 16.6%, P &lt; .001).

CONCLUSIONS

NIV occupies an important role in the management of acute respiratory failure in acute care hospitals in selected US hospitals and is being used for a large majority of patients with acute-on-chronic respiratory failure and acute cardiogenic pulmonary edema. NIV use appears to have increased substantially in selected US hospitals over the past decade.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00458926; URL: www.clinicaltrials.gov.

Moderate-dose glucocorticoids as salvage therapy for severe pneumonia in renal transplant recipients: a single-center feasibility study

This study aimed to assess the effectiveness and safety of moderate-dose glucocorticoids (GCs) with mechanical ventilation as salvage therapy for renal transplant recipients with severe pneumonia, which was non-responsive to conventional treatment. A retrospective study was conducted involving renal transplant recipients diagnosed with severe pneumonia and did not respond to conventional treatment. All immunosuppressants were then completely withdrawn, and the patients were initially administered with methylprednisolone at doses of 2.0-2.5 mg/kg/day once every 12 h. This dosage was continued until oxygenation improved, and the treatment was gradually tapered (by 20 mg every 2-3 days) to the previous maintenance dosage. Ten patients were recruited from year 2008 to 2012. Two patients who underwent emergency endotracheal intubation were intubated on days 3 and 8, respectively, another one died from recurrent pneumothorax. The mean PaO2/FiO2 of the nine survivors was significantly increased by the increasing treatment duration; whereas the lung injury scores (LIS) and the sequential organ failure assessment (SOFA) score were both significantly decreased. The use of moderate-dose GCs may play a role as salvage therapy for renal transplant recipients with severe pneumonia. However, further study with larger trials to is needed.

[Prehospital non-invasive ventilation in Germany: results of a nationwide survey of ground-based emergency medical services]

BACKGROUND AND OBJECTIVES

Non-invasive ventilation (NIV) is an evidence-based treatment of acute respiratory failure and can be helpful to reduce morbidity and mortality. In Germany national S3 guidelines for inhospital use of NIV based on a large number of clinical trials were published in 2008; however, only limited data for prehospital non-invasive ventilation (pNIV) and hence no recommendations for prehospital use exist so far.

AIM

In order to create a database for pNIV in Germany a nationwide survey was conducted to explore the status quo for the years 2005-2008 and to survey expected future developments including disposability, acceptance and frequency of pNIV.

MATERIAL AND METHODS

A questionnaire on the use of pNIV was developed and distributed to 270 heads of medical emergency services in Germany.

RESULTS

Of the 270 questionnaires distributed 142 could be evaluated (52 %). The pNIV was rated as a reasonable treatment option in 91 % of the respondents but was available in only 54 out of the 142 responding emergency medical services (38 %). Continuous positive airway pressure (98 %) and biphasic positive airway pressure (22 %) were the predominantly used ventilation modes. Indications for pNIV use were acute cardiogenic pulmonary edema (96 %), acute exacerbation of chronic obstructive pulmonary disease (89 %), asthma (32 %) and pneumonia (28 %). Adverse events were reported for panic (20 ±  17%) and non-threatening heart rhythm disorders (8 ± 5%), the rate of secondary intubation was low (reduction from 20 % to 10 %) and comparable to data from inhospital treatment.

CONCLUSION

Prehospital NIV in Germany was used by only one third of all respondents by the end of 2008. Based on the clinical data a growing application for pNIV is expected. Controlled prehospital studies are needed to enunciate evidence-based recommendations for pNIV.

Chronic obstructive pulmonary disease: clinical review and update on consensus guidelines

In the last 2 decades, chronic obstructive pulmonary disease (COPD) has been increasingly recognized as a major public health problem. Since the introduction of the Global Initiative for Chronic Obstructive Lung Disease in 1998, growing interest in the pathogenesis and management of patients with COPD has led to notable improvements in patient care and quality of life. Despite greater awareness of this common preventable disease and major therapeutic advances during this period, the global impact of COPD remains strikingly large. We provide an evidence-based clinical review on COPD, with a focus on internists as the target audience.

Use of dexmedetomidine to facilitate non-invasive ventilation

Patients with chronic obstructive pulmonary disease and congestive heart failure exacerbations, as well as pneumonia benefit from the use of non-invasive ventilation (NIV), due to increased patient comfort and a reduced incidence of ventilator-associated pneumonia. However, some patients do not tolerate NIV due to anxiety or agitation, and traditionally physicians have withheld sedation from these patients due to concerns of loss of airway protection and respiratory depression. We report our recent experience with a 91-year-old female who received NIV for acute respiratory distress secondary to pneumonia. The duration of NIV was a total time period of 86 h, using the bilevel positive airway pressure mode via a full face mask. The patient was initially agitated with the NIV, but with the addition of the dexmedetomidine, she tolerated it well. The dexmedetomidine was administered without a loading dose, as a continuous infusion ranging from 0.2 to 0.5 mcg/kg/hr, titrated to a Ramsey score of three. This case illustrates the safe use of dexmedetomidine to facilitate NIV, and improve compliance, which may reduce ICU length of stay.

Acute and chronic respiratory failure

Respiratory failure (RF) can be attributed to a plethora of neuromuscular diseases (NMDs) and manifests clinically in a multitude of overt or more subtle ways. The basic principles of pathophysiology, diagnosis and treatment of neurologic diseases and of RF apply concomitantly to this subset of patients. Various entities should be approached according to the latest evidence-based recommendations. Treatment follows the natural disease progression, from minimal respiratory assistance to mechanical ventilation (MV). A comprehensive treatment plan has to be formulated that takes into consideration the patient's wishes.

[Ten-year evolution of mechanical ventilation in acute respiratory failure in the hematogical patient admitted to the intensive care unit]

OBJECTIVE

A comparison was made between invasive mechanical ventilation (IMV) and noninvasive positive pressure ventilation (NPPV) in haematological patients with acute respiratory failure.

DESIGN

A retrospective observational study was made from 2001 to December 2011.

SETTING

A clinical-surgical intensive care unit (ICU) in a tertiary hospital.

PATIENTS

Patients with hematological malignancies suffering acute respiratory failure (ARF) and requiring mechanical ventilation in the form of either IMV or NPPV.

VARIABLES OF INTEREST

Analysis of infection and organ failure rates, duration of mechanical ventilation and ICU and hospital stays, as well as ICU, hospital and mortality after 90 days. The same variables were analyzed in the comparison between NPPV success and failure.

RESULTS

Forty-one patients were included, of which 35 required IMV and 6 NPPV. ICU mortality was higher in the IMV group (100% vs 37% in NPPV, P=.006). The intubation rate in NPPV was 40%. Compared with successful NPPV, failure in the NPPV group involved more complications, a longer duration of mechanical ventilation and ICU stay, and greater ICU and hospital mortality. Multivariate analysis of mortality in the NPPV group identified NPPV failure (OR 13 [95%CI 1.33-77.96], P=.008) and progression to acute respiratory distress syndrome (OR 10 [95%CI 1.95-89.22], P=.03) as prognostic factors.

CONCLUSION

The use of NPPV reduced mortality compared with IMV. NPPV failure was associated with more complications.

Clinical review: Helmet and non-invasive mechanical ventilation in critically ill patients

Non-invasive mechanical ventilation (NIV) has proved to be an excellent technique in selected critically ill patients with different forms of acute respiratory failure. However, NIV can fail on account of the severity of the disease and technical problems, particularly at the interface. The helmet could be an alternative interface compared to face mask to improve NIV success. We performed a clinical review to investigate the main physiological and clinical studies assessing the efficacy and related issues of NIV delivered with a helmet. A computerized search strategy of MEDLINE/PubMed (January 2000 to May 2012) and EMBASE (January 2000 to May 2012) was conducted limiting the search to retrospective, prospective, nonrandomized and randomized trials. We analyzed 152 studies from which 33 were selected, 12 physiological and 21 clinical (879 patients). The physiological studies showed that NIV with helmet could predispose to CO₂ rebreathing and increase the patients' ventilator asynchrony. The main indications for NIV were acute cardiogenic pulmonary edema, hypoxemic acute respiratory failure (community-acquired pneumonia, postoperative and immunocompromised patients) and hypercapnic acute respiratory failure. In 9 of the 21 studies the helmet was compared to a face mask during either continous positive airway pressure or pressure support ventilation. In eight studies oxygenation was similar in the two groups, while the intubation rate was similar in four and lower in three studies for the helmet group compared to face mask group. The outcome was similar in six studies. The tolerance was better with the helmet in six of the studies. Although these data are limited, NIV delivered by helmet could be a safe alternative to the face mask in patients with acute respiratory failure.

Complications of non-invasive ventilation techniques: a comprehensive qualitative review of randomized trials

Non-invasive ventilation (NIV) has become a common treatment for acute and chronic respiratory failure. In comparison with conventional invasive mechanical ventilation, NIV has the advantages of reducing patient discomfort, procedural complications, and mortality. However, NIV is associated with frequent uncomfortable or even life-threatening adverse effects, and patients should be thoroughly screened beforehand to reduce potential severe complications. We performed a detailed review of the relevant medical literature for NIV complications. All major NIV complications are potentially life-threatening and can occur in any patient, but are strongly correlated with the degree of pulmonary and cardiovascular involvement. Minor complications can be related to specific structural features of NIV interfaces or to variable airflow patterns. This extensive review of the literature shows that careful selection of patients and interfaces, proper setting of ventilator modalities, and close monitoring of patients from the start can greatly reduce NIV complications.

Neurally adjusted ventilatory assist vs pressure support ventilation for noninvasive ventilation during acute respiratory failure: a crossover physiologic study

BACKGROUND

Patient-ventilator asynchrony is common during noninvasive ventilation (NIV) with pressure support ventilation (PSV). We examined the effect of neurally adjusted ventilatory assist (NAVA) delivered through a facemask on synchronization in patients with acute respiratory failure (ARF).

METHODS

This was a prospective, physiologic, crossover study of 13 patients with ARF (median Pa(O(2))/F(IO(2)), 196 [interquartile range (IQR), 142-225]) given two 30-min trials of NIV with PSV and NAVA in random order. Diaphragm electrical activity (EAdi), neural inspiratory time (T(In)), trigger delay (Td), asynchrony index (AI), arterial blood gas levels, and patient discomfort were recorded.

RESULTS

There were significantly fewer asynchrony events during NAVA than during PSV (10 [IQR, 5-14] events vs 17 [IQR, 8-24] events, P = .017), and the occurrence of severe asynchrony (AI > 10%) was also less under NAVA (P = .027). Ineffective efforts and delayed cycling were significantly less with NAVA (P < .05 for both). NAVA was also associated with reduced Td (0 [IQR, 0-30] milliseconds vs 90 [IQR, 30-130] milliseconds, P < .001) and inspiratory time in excess (10 [IQR, 0-28] milliseconds vs 125 [IQR, 20-312] milliseconds, P < .001), but T(In) was similar under PSV and NAVA. The EAdi signal to its maximal value was higher during NAVA than during PSV ( P = .017). There were no significant differences in arterial blood gases or patient discomfort under PSV and NAVA.

CONCLUSION

In view of specific experimental conditions, our comparison of PSV and NAVA indicated that NAVA significantly reduced severe patient-ventilator asynchrony and resulted in similar improvements in gas exchange during NIV for ARF.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01426178; URL: www.clinicaltrials.gov.