Analysis of shared cognitive tasks in the application of non-invasive ventilation to patients with COPD exacerbation.

Interprofessional teamwork plays a key role in the uptake of evidence-based interventions, such as noninvasive ventilation (NIV) for patients with exacerbated Chronic Obstructive Pulmonary Disease (COPD). We aimed to identify the shared cognitive tasks in interprofessional teams using NIV for patients with COPD exacerbation. We used a cognitive task analysis approach (CTA) to engage nurses, rapid response team members, respiratory therapists, and physicians involved in the use of NIV to treat patients with COPD exacerbation. Clinicians participated in a semi-structured interview (n = 21) that elicited cognitions needed to treat COPD exacerbation. Three shared cognitive tasks were identified: Complete a thorough assessment, Formulate a care plan, and Continuously monitor patient status. Findings attest to the importance of having access to up-to-date information and expertise necessary to make accurate clinical inferences for patient assessment. Shared understanding of the formulated care plan among all members of the care team was important to its execution. Continuous monitoring was crucial; however, this cognitive task relied on patient assessment skills and ongoing collaboration within the clinical care team. Application of NIV for patients with COPD exacerbation may require enhancing collaboration through nontechnical skills and interprofessional training.

Long-Term Noninvasive Ventilation in Chronic Stable Hypercapnic Chronic Obstructive Pulmonary Disease. An Official American Thoracic Society Clinical Practice Guideline.

Background: Noninvasive ventilation (NIV) is used for patients with chronic obstructive pulmonary disease (COPD) and chronic hypercapnia. However, evidence for clinical efficacy and optimal management of therapy is limited.Target Audience: Patients with COPD, clinicians who care for them, and policy makers.Methods: We summarized evidence addressing five PICO (patients, intervention, comparator, and outcome) questions. The GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach was used to evaluate the certainty in evidence and generate actionable recommendations. Recommendations were formulated by a panel of pulmonary and sleep physicians, respiratory therapists, and methodologists using the Evidence-to-Decision framework.Recommendations:1) We suggest the use of nocturnal NIV in addition to usual care for patients with chronic stable hypercapnic COPD (conditional recommendation, moderate certainty); 2) we suggest that patients with chronic stable hypercapnic COPD undergo screening for obstructive sleep apnea before initiation of long-term NIV (conditional recommendation, very low certainty); 3) we suggest not initiating long-term NIV during an admission for acute-on-chronic hypercapnic respiratory failure, favoring instead reassessment for NIV at 2-4 weeks after resolution (conditional recommendation, low certainty); 4) we suggest not using an in-laboratory overnight polysomnogram to titrate NIV in patients with chronic stable hypercapnic COPD who are initiating NIV (conditional recommendation, very low certainty); and 5) we suggest NIV with targeted normalization of PaCO2 in patients with hypercapnic COPD on long-term NIV (conditional recommendation, low certainty).Conclusions: This expert panel provides evidence-based recommendations addressing the use of NIV in patients with COPD and chronic stable hypercapnic respiratory failure.

A Comparative Analysis of Pulmonary and Critical Care Medicine Guideline Development Methodologies.

RATIONALE: The Institute of Medicine (IOM) standards for guideline development have had unintended negative consequences. A more efficient approach is desirable. OBJECTIVES: To determine whether a modified Delphi process early during guideline development discriminates recommendations that should be informed by a systematic review from those that can be based upon expert consensus. METHODS: The same questions addressed by IOM-compliant pulmonary or critical care guidelines were addressed by expert panels using a modified Delphi process, termed the Convergence of Opinion on Recommendations and Evidence (CORE) process. The resulting recommendations were compared. Concordance of the course of action, strength of recommendation, and quality of evidence, as well as the duration of recommendation development, were measured. MEASUREMENTS AND MAIN RESULTS: When 50% agreement was required to make a recommendation, all questions yielded recommendations, and the recommended courses of action were 89.6% concordant. When 70% agreement was required, 17.9% of questions did not yield recommendations, but for those that did, the recommended courses of action were 98.2% concordant. The time to completion was shorter for the CORE process (median, 19.3 vs. 1,309.0 d; P = 0.0002). CONCLUSIONS: We propose the CORE process as an early step in guideline creation. Questions for which 70% agreement on a recommendation cannot be achieved should go through an IOM-compliant process; however, questions for which 70% agreement on a recommendation can be achieved can be accepted, avoiding a lengthy systematic review.

High-flow oxygen therapy and other inhaled therapies in intensive care units.

In this Series paper, we review the current evidence for the use of high-flow oxygen therapy, inhaled gases, and aerosols in the care of critically ill patients. The available evidence supports the use of high-flow nasal cannulae for selected patients with acute hypoxaemic respiratory failure. Heliox might prevent intubation or improve gas flow in mechanically ventilated patients with severe asthma. Additionally, it might improve the delivery of aerosolised bronchodilators in obstructive lung disease in general. Inhaled nitric oxide might improve outcomes in a subset of patients with postoperative pulmonary hypertension who had cardiac surgery; however, it has not been shown to provide long-term benefit in patients with acute respiratory distress syndrome (ARDS). Inhaled prostacyclins, similar to inhaled nitric oxide, are not recommended for routine use in patients with ARDS, but can be used to improve oxygenation in patients who are not adequately stabilised with traditional therapies. Aerosolised bronchodilators are useful in mechanically ventilated patients with asthma and chronic obstructive pulmonary disease, but are not recommended for those with ARDS. Use of aerosolised antibiotics for ventilator-associated pneumonia and ventilator-associated tracheobronchitis shows promise, but the delivered dose can be highly variable if proper attention is not paid to the delivery method.

Cost and Utility of Microbiological Cultures Early After Intensive Care Unit Admission for Intracerebral Hemorrhage.

BACKGROUND: Fever is common among intensive care unit (ICU) patients. Clinicians may use microbiological cultures to differentiate infectious and aseptic fever. However, their utility depends on the prevalence of infection; and false-positive results might adversely affect patient care. We sought to quantify the cost and utility of microbiological cultures in a cohort of ICU patients with spontaneous intracerebral hemorrhage (ICH). METHODS: We performed a secondary analysis of a cohort with spontaneous ICH requiring mechanical ventilation. We collected baseline data, measures of systemic inflammation, microbiological culture results for the first 48 h, and daily antibiotic usage. Two physicians adjudicated true-positive and false-positive culture results using standard criteria. We calculated the cost per true-positive result and used logistic regression to test the association between false-positive results with subsequent antibiotic exposure. RESULTS: Overall, 697 subjects were included. A total of 233 subjects had 432 blood cultures obtained, with one true-positive (diagnostic yield 0.1 %, $22,200 per true-positive) and 11 false-positives. True-positive urine cultures (5 %) and sputum cultures (13 %) were more common but so were false-positives (6 and 17 %, respectively). In adjusted analysis, false-positive blood and sputum results were associated with increased antibiotic exposure. CONCLUSIONS: The yield of blood cultures early after spontaneous ICH was very low. False-positive results significantly increased the odds of antibiotic exposure. Our results support limiting the use of blood cultures in the first two days after ICU admission for spontaneous ICH.

The Regulation of Proresolving Lipid Mediator Profiles in Baboon Pneumonia by Inhaled Carbon Monoxide.

Strategies for the treatment of bacterial pneumonia beyond traditional antimicrobial therapy have been limited. The recently discovered novel genus of lipid mediators, coined "specialized proresolving mediators" (SPMs), which orchestrate clearance of recruited leukocytes and restore epithelial barrier integrity, have offered new insight into the resolution of inflammation. We performed lipid mediator (LM) metabololipidomic profiling and identification of LMs on peripheral blood leukocytes and plasma from a baboon model of Streptococcus pneumoniae pneumonia. Leukocytes and plasma were isolated from whole blood of S. pneumoniae-infected (n = 5-6 per time point) and control, uninfected baboons (n = 4 per time point) at 0, 24, 48, and 168 hours. In a subset of baboons with pneumonia (n = 3), we administered inhaled carbon monoxide (CO) at 48 hours (200-300 ppm for 60-90 min). Unstimulated leukocytes from control animals produced a proresolving LM signature with elevated resolvins and lipoxins. In contrast, serum-treated, zymosan-stimulated leukocytes and leukocytes from baboons with S. pneumoniae pneumonia produced a proinflammatory LM signature profile with elevated leukotriene B4 and prostaglandins. Plasma from baboons with S. pneumoniae pneumonia also displayed significantly reduced LM-SPM levels, including eicosapentaenoic acid-derived E-series resolvins (RvE) and lipoxins. CO inhalation increased levels of plasma RvE and lipoxins relative to preexposure levels. These results establish the leukocyte and plasma LM profiles biosynthesized during S. pneumoniae pneumonia in baboons and provide evidence for pneumonia-induced dysregulation of these proresolution programs. Moreover, these SPM profiles are partially restored with inhaled low-dose CO and SPM, which may shorten the time to pneumonia resolution.

Effects of inhaled CO administration on acute lung injury in baboons with pneumococcal pneumonia.

Inhaled carbon monoxide (CO) gas has therapeutic potential for patients with acute respiratory distress syndrome if a safe, evidence-based dosing strategy and a ventilator-compatible CO delivery system can be developed. In this study, we used a clinically relevant baboon model of Streptococcus pneumoniae pneumonia to 1) test a novel, ventilator-compatible CO delivery system; 2) establish a safe and effective CO dosing regimen; and 3) investigate the local and systemic effects of CO therapy on inflammation and acute lung injury (ALI). Animals were inoculated with S. pneumoniae (10(8)-10(9) CFU) (n = 14) or saline vehicle (n = 5); in a subset with pneumonia (n = 5), we administered low-dose, inhaled CO gas (100-300 ppm × 60-90 min) at 0, 6, 24, and/or 48 h postinoculation and serially measured blood carboxyhemoglobin (COHb) levels. We found that CO inhalation at 200 ppm for 60 min is well tolerated and achieves a COHb of 6-8% with ambient CO levels ≤ 1 ppm. The COHb level measured at 20 min predicted the 60-min COHb level by the Coburn-Forster-Kane equation with high accuracy. Animals given inhaled CO + antibiotics displayed significantly less ALI at 8 days postinoculation compared with antibiotics alone. Inhaled CO was associated with activation of mitochondrial biogenesis in the lung and with augmentation of renal antioxidative programs. These data support the feasibility of safely delivering inhaled CO gas during mechanical ventilation and provide preliminary evidence that CO may accelerate the resolution of ALI in a clinically relevant nonhuman primate pneumonia model.

Ventilatory strategies in severe acute respiratory failure.

Lung-protective ventilator strategies are considered standard practice in the care of patients with the acute respiratory distress syndrome (ARDS). To minimize ventilator-induced lung injury, attention is directed at avoidance of alveolar overdistention and cyclical opening and closing. The lowest possible plateau pressure and tidal volume (V(T)) should be selected. A reasonable target V(T) in all mechanically ventilated patients is 6 mL/kg. A topic of much controversy is the optimal setting of positive end-expiratory pressure (PEEP). Results of a meta-analysis using individual patient data from three randomized controlled trials suggest that higher PEEP should be used for moderate and severe ARDS, whereas lower PEEP may be more appropriate in patients with mild ARDS. PEEP should be set to maximize alveolar recruitment while avoiding overdistention. Volume and pressure limitation during mechanical ventilation can be described in terms of stress and strain. Fraction of inspired oxygen (Fio(2)) and PEEP are typically titrated to maintain arterial oxygen saturation (Spo(2)) of 88 to 95% (Pao(2) 55-80 mm Hg). There is currently no clear proven benefit for advanced modes.

Statistics for the Non-Statistician: How to Read the Respiratory Care Literature.

Statistical analysis is an important part of the research process. Researchers are advised to include a statistician from the moment that the study is being planned. The statistical plan informs the research process, including sample size requirements and the most robust data collection. Once the data are collected, descriptive and inferential statistical analyses are performed. The results of this analysis determine whether the findings are significant, which leads to an interpretation of the findings. The importance of the statistical plan and analysis for the researcher is self-evident. However, it is also important for the reader of published papers to have some knowledge of statistical analysis. This allows critical review of all aspects of the published manuscript. The intent of this paper is to review some basic statistical concepts and thus allow the reader to become a better consumer of the literature.

Pulse Oximetry: 2023 Year in Review.

Pulse oximetry is arguably the most impactful monitor ever introduced into respiratory care practice. Recently there has been increased attention to the problem of occult hypoxemia in which patients are hypoxemic despite an acceptable SpO2 Although occult hypoxemia might be greater in Black patients than white patients, it is not insignificant in whites. In a given population of patients, the bias between SpO2 and arterial oxygen saturation (SaO2 ) might be close to zero. However, the limits of agreement can be wide, meaning that SpO2 might overestimate SaO2 in many individual patients, which can result in occult hypoxemia in some. Manufactures report accuracy of SpO2 derived from normal individuals, which might differ from that in the clinical setting. That SpO2 overestimates SaO2 in an important number of individuals has caused some to recommend higher SpO2 targets to avoid occult hypoxemia. There is also evidence that suggests that SpO2 might not accurately trend SaO2 Additional research is needed to investigate strategies to mitigate the bias between SpO2 and SaO2 Clinicians must be cognizant of the limitations of pulse oximetry when clinically using SpO2 The aim of this paper is to provide an update on pulse oximetry.

AARC Clinical Practice Guideline: Spontaneous Breathing Trials for Liberation From Adult Mechanical Ventilation.

Despite prior publications of clinical practice guidelines related to ventilator liberation, some questions remain unanswered. Many of these questions relate to the details of bedside implementation. We, therefore, formed a guidelines committee of individuals with experience and knowledge of ventilator liberation as well as a medical librarian. Using Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, we make the following recommendations: (1) We suggest that calculation of a rapid shallow breathing index is not needed to determine readiness for a spontaneous breathing trial (SBT) (conditional recommendation; moderate certainty); (2) We suggest that SBTs can be conducted with or without pressure support ventilation (conditional recommendation, moderate certainty); (3) We suggest a standardized approach to assessment and, if appropriate, completion of an SBT before noon each day (conditional recommendation, very low certainty); and (4) We suggest that FIO2 should not be increased during an SBT (conditional recommendation, very low certainty). These recommendations are intended to assist bedside clinicians to liberate adult critically ill patients more rapidly from mechanical ventilation.

Acute respiratory distress syndrome after spontaneous intracerebral hemorrhage*.

OBJECTIVES: Acute respiratory distress syndrome develops commonly in critically ill patients in response to an injurious stimulus. The prevalence and risk factors for development of acute respiratory distress syndrome after spontaneous intracerebral hemorrhage have not been reported. We sought to determine the prevalence of acute respiratory distress syndrome after intracerebral hemorrhage, characterize risk factors for its development, and assess its impact on patient outcomes. DESIGN: Retrospective cohort study at two academic centers. PATIENTS: We included consecutive patients presenting from June 1, 2000, to November 1, 2010, with intracerebral hemorrhage requiring mechanical ventilation. We excluded patients with age less than 18 years, intracerebral hemorrhage secondary to trauma, tumor, ischemic stroke, or structural lesion; if they required intubation only during surgery; if they were admitted for comfort measures; or for a history of immunodeficiency. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data were collected both prospectively as part of an ongoing cohort study and by retrospective chart review. Of 1,665 patients identified by database query, 697 met inclusion criteria. The prevalence of acute respiratory distress syndrome was 27%. In unadjusted analysis, high tidal volume ventilation was associated with an increased risk of acute respiratory distress syndrome (hazard ratio, 1.79 [95% CI, 1.13-2.83]), as were male sex, RBC and plasma transfusion, higher fluid balance, obesity, hypoxemia, acidosis, tobacco use, emergent hematoma evacuation, and vasopressor dependence. In multivariable modeling, high tidal volume ventilation was the strongest risk factor for acute respiratory distress syndrome development (hazard ratio, 1.74 [95% CI, 1.08-2.81]) and for inhospital mortality (hazard ratio, 2.52 [95% CI, 1.46-4.34]). CONCLUSIONS: Development of acute respiratory distress syndrome is common after intubation for intracerebral hemorrhage. Modifiable risk factors, including high tidal volume ventilation, are associated with its development and in-patient mortality.

Development and validation of a score for prediction of postoperative respiratory complications.

BACKGROUND: Postoperative respiratory failure is associated with increased morbidity and mortality, as well as high costs of hospital care. METHODS: Using electronic anesthesia records, billing data, and chart review, the authors developed and validated a score predicting reintubation in the hospital after primary extubation in the operating room, leading to unplanned mechanical ventilation within the first 3 postoperative days. Using multivariable logistic regression analysis, independent predictors were determined and a score postulated and validated. RESULTS: In the entire cohort (n = 33,769 surgical cases within 29,924 patients), reintubation occurred in 137 cases (0.41%). Of those, 16%, (n = 22) died subsequently, whereas the mortality in patients who were not reintubated was 0.26% (P < 0.0001). Independent predictors for reintubation were: American Society of Anesthesiologist Score 3 or more, emergency surgery, high-risk surgical service, history of congestive heart failure, and chronic pulmonary disease. A point value of 3, 3, 2, 2, and 1 were assigned to these predictors, respectively, based on their ß coefficient in the predictive model. The score yielded a calculated area under the curve of 0.81, whereas each point increment was associated with a 1.7-fold (odds ratio: 1.72 [95% CI, 1.55-1.91]) increase in the odds for reintubation in the training dataset. Using the validation dataset (n = 16,884), the score had an area under the curve of 0.80 and similar estimated probabilities for reintubation. CONCLUSION: The authors developed and validated a score for the prediction of postoperative respiratory complications, a simple, 11-point score that can be used preoperatively by anesthesiologists to predict severe postoperative respiratory complications.

How to Write an Effective Discussion.

Explaining the meaning of the results to the reader is the purpose of the discussion section of a research paper. There are elements of the discussion section that should be included and pitfalls that should be avoided. Always write the discussion section for the reader. Remember that the focus is to help the reader understand the study and that the focus should be on the study data.

Respiratory Care Management of COPD Exacerbations.

A COPD exacerbation is characterized by an increase in symptoms such as dyspnea, cough, and sputum production that worsens over a period of 2 weeks. Exacerbations are common. Respiratory therapists and physicians in an acute care setting often treat these patients. Targeted O2 therapy improves outcomes and should be titrated to an SpO2 of 88-92%. Arterial blood gases remain the standard approach to assessing gas exchange in patients with COPD exacerbation. The limitations of arterial blood gas surrogates (pulse oximetry, capnography, transcutaneous monitoring, peripheral venous blood gases) should be appreciated so that they can be used wisely. Inhaled short-acting bronchodilators can be provided by nebulizer (jet or mesh), pressurized metered-dose inhaler (pMDI), pMDI with spacer or valved holding chamber, soft mist inhaler, or dry powder inhaler. The available evidence for the use of heliox for COPD exacerbation is weak. Noninvasive ventilation (NIV) is standard therapy for patients who present with COPD exacerbation and is supported by clinical practice guidelines. Robust high-level evidence with patient important outcomes is lacking for the use of high-flow nasal cannula in patients with COPD exacerbation. Management of auto-PEEP is the priority in mechanically ventilated patients with COPD. This is achieved by reducing airway resistance and decreasing minute ventilation. Trigger asynchrony and cycle asynchrony are addressed to improve patient-ventilator interaction. Patients with COPD should be extubated to NIV. Additional high-level evidence is needed before widespread use of extracorporeal CO2 removal. Care coordination can improve the effectiveness of care for patients with COPD exacerbation. Evidence-based practices improve outcomes in patients with COPD exacerbation.

Research and Publication in Respiratory Care.

The evidence that informs respiratory care practice arises from research that generates facts based on the scientific method. A simple definition of research is that it is a method for finding answers to questions. The Common Rule establishes guidelines related to human subjects research, but there are many types of research not subject to the Common Rule. Although conducting research can elevate the stature of investigators, more importantly, it is an essential attribute of a profession to generate research to support clinical practice.

Observational Studies.

Studies can be observational or experimental. With an observational study, the investigator does not determine the assignment of subjects, and there might not be a control group. If there is a control group, assignment of the independent variable (exposure or intervention) is not under the control of the investigator. Observational studies can be rigorously conducted, but the lack of random assignment of the exposure/intervention introduces confounding and bias. Thus, the quality of evidence resulting from observational studies is lower than that of experimental randomized controlled trials (RCTs). An observational study might be performed if an RCT is unethical, impractical, or outside the control of the investigator. There are many types of prospective and retrospective observational study designs. However, an observational study design should be avoided if an experimental study is possible. Sophisticated statistical approaches can be used, but this does not elevate an observational study to the level of an RCT. Regardless of quality, an observational study cannot establish causality.

The role of noninvasive ventilation in the ventilator discontinuation process.

In recent years, there has been increasing interest in the use of noninvasive ventilation (NIV) in the post-extubation period to shorten the length of invasive ventilation, to prevent extubation failure, and to rescue a failed extubation. The purpose of this review is to summarize the evidence related to the use of NIV in these settings. NIV can be used to allow earlier extubation in selected patients who do not successfully complete a spontaneous breathing trial (SBT). Its use in this setting should be restricted to patients who are intubated during an exacerbation of COPD or patients with neuromuscular disease. This category of patients should be good candidates for NIV and should be extubated directly to NIV. In patients who successfully complete an SBT, but are at risk for extubation failure, NIV can be used to prevent extubation failure. These patients should also be good candidates for NIV and should be extubated directly to NIV. NIV should be used cautiously in patients who successfully complete an SBT, but develop respiratory failure within 48 hours post-extubation. In this setting, NIV is indicated only in patients with hypercapnic respiratory failure. Reintubation should not be delayed if NIV is not immediately successful in reversing the post-extubation respiratory failure. Evidence does not support routine use of NIV post-extubation.

The growing role of noninvasive ventilation in patients requiring prolonged mechanical ventilation.

For many patients with chronic respiratory failure requiring ventilator support, noninvasive ventilation (NIV) is preferable to invasive support by tracheostomy. Currently available evidence does not support the use of nocturnal NIV in unselected patients with stable COPD. Several European studies have reported benefit for high intensity NIV, in which setting of inspiratory pressure and respiratory rate are selected to achieve normocapnia. There have also been studies reporting benefit for the use of NIV as an adjunct to exercise training. NIV may be useful as an adjunct to airway clearance techniques in patients with cystic fibrosis. Accumulating evidence supports the use of NIV in patients with obesity hypoventilation syndrome. There is considerable observational evidence supporting the use of NIV in patients with chronic respiratory failure related to neuromuscular disease, and one randomized controlled trial reported that the use of NIV was life-prolonging in patients with amyotrophic lateral sclerosis. A variety of interfaces can be used to provide NIV in patients with stable chronic respiratory failure. The mouthpiece is an interface that is unique in this patient population, and has been used with success in patients with neuromuscular disease. Bi-level pressure ventilators are commonly used for NIV, although there are now a new generation of intermediate ventilators that are portable, have a long battery life, and can be used for NIV and invasive applications. Pressure support ventilation, pressure controlled ventilation, and volume controlled ventilation have been used successfully for chronic applications of NIV. New modes have recently become available, but their benefits await evidence to support their widespread use. The success of NIV in a given patient population depends on selection of an appropriate patient, selection of an appropriate interface, selection of an appropriate ventilator and ventilator settings, the skills of the clinician, the motivation of the patient, and the support of the family.

Respiratory care year in review 2011: long-term oxygen therapy, pulmonary rehabilitation, airway management, acute lung injury, education, and management.

For the busy clinician, educator, or manager, it is becoming an increasing challenge to filter the literature to what is relevant to one's practice and then update one's practice based on the current evidence. The purpose of this paper is to review the recent literature related to long-term oxygen therapy, pulmonary rehabilitation, airway management, acute lung injury and acute respiratory distress syndrome, respiratory care education, and respiratory care management. These topics were chosen and reviewed in a manner that is most likely to have interest to the readers of Respiratory Care.