Clinical Effectiveness of Incentive Spirometry for the Prevention of Postoperative Pulmonary Complications

Incentive spirometry (IS) is commonly prescribed to reduce pulmonary complications, despite limited evidence to support its benefits and a lack of consensus on optimal protocols for its use. Although numerous studies and meta-analyses have examined the effects of IS on patient outcomes, there is no clear evidence establishing its benefit to prevent postoperative pulmonary complications. Clinical practice guidelines advise against the routine use of IS in postoperative care. Until evidence of benefit from well-designed clinical trials becomes available, the routine use of IS in postoperative care is not supported by high levels of evidence.

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.

Respiratory Compromise as a New Paradigm for the Care of Vulnerable Hospitalized Patients

Acute respiratory compromise describes a deterioration in respiratory function with a high likelihood of rapid progression to respiratory failure and death. Identifying patients at risk for respiratory compromise coupled with monitoring of patients who have developed respiratory compromise might allow earlier interventions to prevent or mitigate further decompensation. The National Association for the Medical Direction of Respiratory Care (NAMDRC) organized a workshop meeting with representation from many national societies to address the unmet needs of respiratory compromise from a clinical practice perspective. Respiratory compromise may arise de novo or may complicate preexisting lung disease. The group identified distinct subsets of respiratory compromise that present similar opportunities for early detection and useful intervention to prevent respiratory failure. The subtypes were characterized by the pathophysiological mechanisms they had in common: impaired control of breathing, impaired airway protection, parenchymal lung disease, increased airway resistance, hydrostatic pulmonary edema, and right-ventricular failure. Classification of acutely ill respiratory patients into one or more of these categories may help in selecting the screening and monitoring strategies that are most appropriate for the patient's particular pathophysiology. Standardized screening and monitoring practices for patients with similar mechanisms of deterioration may enhance the ability to predict respiratory failure early and prevent its occurrence.

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.

Inhaled Carbon Monoxide: From Toxin to Therapy

Carbon monoxide (CO) is usually recognized as a toxic gas that can be used to assess lung function in the pulmonary function laboratory. The toxicity of CO relates to its high affinity for hemoglobin and other heme molecules, producing carboxyhemoglobin (HbCO). Despite that blood HbCO levels are commonly measured in patients with CO poisoning, the clinical presentation often does not correlate with the HbCO level, and clinical improvement in the patient's condition does not correlate with HbCO clearance. In patients with CO poisoning, administration of 100% O₂ is standard practice. If available, hyperbaric O₂ can be used, although this is controversial. Measurement of exhaled CO might be useful to estimate HbCO, such as in smoking cessation programs, but assessment of HbCO using pulse oximetry can be misleading. Endogenous CO is generated as the result of heme oxygenase activity. It is becoming increasingly recognized that the results of heme oxygenase activity, specifically CO production, might have important physiologic functions. These include effects on vascular function, inflammation, apoptosis, cell proliferation, and signaling pathways. Given the abundance of basic science supporting a therapeutic role for CO, clinical trials are exploring this potential.

Update in Management of Severe Hypoxemic Respiratory Failure

Mortality related to severe-moderate and severe ARDS remains high. We searched the literature to update this topic. We defined severe hypoxemic respiratory failure as Pao₂/Fio₂ < 150 mm Hg (ie, severe-moderate and severe ARDS). For these patients, we support setting the ventilator to a tidal volume of 4 to 8 mL/kg predicted body weight (PBW), with plateau pressure (Pplat) ≤ 30 cm H₂O, and initial positive end-expiratory pressure (PEEP) of 10 to 12 cm H₂O. To promote alveolar recruitment, we propose increasing PEEP in increments of 2 to 3 cm provided that Pplat remains ≤ 30 cm H₂O and driving pressure does not increase. A fluid-restricted strategy is recommended, and nonrespiratory causes of hypoxemia should be considered. For patients who remain hypoxemic after PEEP optimization, neuromuscular blockade and prone positioning should be considered. Profound refractory hypoxemia (Pao₂/Fio₂ < 80 mm Hg) after PEEP titration is an indication to consider extracorporeal life support. This may necessitate early transfer to a center with expertise in these techniques. Inhaled vasodilators and nontraditional ventilator modes may improve oxygenation, but evidence for improved outcomes is weak.

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.

Aerosol Therapy During Noninvasive Ventilation or High-Flow Nasal Cannula

Noninvasive ventilation (NIV) and high-flow nasal cannula (HFNC) are increasingly used for patients with acute respiratory failure. Some patients receiving these therapies might also benefit from inhaled drug delivery. Thus, it is attractive to combine aerosol therapy with NIV or HFNC. The purpose of this paper is to review the available evidence related to the use of inhaled aerosols with NIV or HFNC. Available evidence supports the delivery of aerosols during NIV. Inhaled bronchodilator response might be improved with the use of NIV in acute asthma, but the evidence is not sufficiently mature to recommend this as standard therapy. Evidence does support aerosol delivery without discontinuation of NIV. Clinical studies on aerosol delivery during HFNC are needed, and based on the available in vitro evidence, it is not possible to make a recommendation for or against aerosol delivery during HFNC.

Regional Ventilation and Aerosol Deposition with Helium-Oxygen in Bronchoconstricted Asthmatic Lungs

BACKGROUND

Theoretical models suggest that He-O2 as carrier gas may lead to more homogeneous ventilation and aerosol deposition than air. However, these effects have not been clinically consistent and it is unclear why subjects may or may not respond to the therapy. Here we present 3D-imaging data of aerosol deposition and ventilation distributions from subjects with asthma inhaling He-O2 as carrier gas. The data are compared with those that we previously obtained from a similar group of subjects inhaling air.

METHODS

Subjects with mild-to-moderate asthma were bronchoconstricted with methacholine and imaged with PET-CT while inhaling aerosol carried with He-O2. Mean-normalized-values of lobar specific ventilation sV* and deposition sD* were derived and the factors affecting the distribution of sD* were evaluated along with the effects of breathing frequency (f) and regional expansion (FVOL).

RESULTS

Lobar distributions of sD* and sV* with He-O2 were not statistically different from those previously measured with air. However, with He-O2 there was a larger number of lobes having sV* and sD* closer to unity and, in those subjects with uneven deposition distributions, the correlation of sD* with sV* was on average higher (p < 0.05) in He-O2 (0.84 ± 0.8) compared with air (0.55 ± 0.28). In contrast with air, where the frequency of breathing during nebulization was associated with the degree of sD*-sV* correlation, with He-O2 there was no association. Also, the modulation of f on the correlation between FVOL and sD*/sV* in air, was not observed in He-O2.

CONCLUSION

There were no differences in the inter-lobar heterogeneity of sD* or sV* in this group of mild asthmatic subjects breathing He-O2 compared with patients previously breathing air. Future studies, using these personalized 3D data sets as input to CFD models, are needed to understand if, and for whom, breathing He-O2 during aerosol inhalation may be beneficial.

Recruitment Maneuvers and PEEP Titration

The injurious effects of alveolar overdistention are well accepted, and there is little debate regarding the importance of pressure and volume limitation during mechanical ventilation. The role of recruitment maneuvers is more controversial. Alveolar recruitment is desirable if it can be achieved, but the potential for recruitment is variable among patients with ARDS. A stepwise recruitment maneuver, similar to an incremental PEEP titration, is favored over sustained inflation recruitment maneuvers. Many approaches to PEEP titration have been proposed, and the best method to choose the most appropriate level for an individual patient is unclear. A PEEP level should be selected that balances alveolar recruitment against overdistention. The easiest approach to select PEEP might be according to the severity of the disease: 5-10 cm H2O PEEP in mild ARDS, 10-15 cm H2O PEEP in moderate ARDS, and 15-20 cm H2O PEEP in severe ARDS. Recruitment maneuvers and PEEP should be used within the context of lung protection and not just as a means of improving oxygenation.

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.

Year in Review 2014: Patient Safety

The topic of patient safety has received much attention in recent years. There are a number of areas in which the subject of patient safety impacts respiratory care practice. This paper focuses on articles published in 2014 related to pressure injury, handoffs, protocols and multidisciplinary teams, perioperative obstructive sleep apnea, and readmissions.

Respiratory care year in review 2013: neonatal respiratory care, pulmonary function testing, and pulmonary rehabilitation

Respiratory care practice includes neonatal respiratory care, pulmonary function testing, and pulmonary rehabilitation. The purpose of this paper is to review the recent literature related to these topics in a manner that is most likely to have interest to the readers of Respiratory Care.

Developing a New, National Approach to Surveillance for Ventilator-Associated Events: Executive Summary

This article is an executive summary of a report from the Centers for Disease Control and Prevention Ventilator-Associated Pneumonia Surveillance Definition Working Group, entitled “Developing a new, national approach to surveillance for ventilator-associated events” and published in Critical Care Medicine. The full report provides a comprehensive description of the Working Group process and outcome.

In September 2011, the Centers for Disease Control and Prevention (CDC) convened a Ventilator-Associated Pneumonia (VAP) Surveillance Definition Working Group to organize a formal process for leaders and experts of key stakeholder organizations to discuss the challenges of VAP surveillance definitions and to propose new approaches to VAP surveillance in adult patients (Table 1).

Respiratory care year in review 2012: Asthma and sleep-disordered breathing

Asthma has long been recognized as a common respiratory disease, and the recognition of sleep-disordered breathing is becoming more prevalent. Patients with these disorders are commonly seen by clinicians caring for patients with respiratory disease. There is also much academic interest in asthma and sleep-disordered breathing. The purpose of this paper is to review the recent literature related to asthma and sleep-disordered breathing in a manner that is most likely to have interest to the readers of Respiratory Care.

Noninvasive ventilation for acute respiratory failure

Noninvasive ventilation (NIV) for acute respiratory failure has gained much academic and clinical interest. Despite this, NIV is underutilized. The evidence strongly supports its use in patients presenting with an exacerbation of COPD and in patients with acute cardiogenic pulmonary edema. As reviewed in this paper, there is now evidence supporting or not supporting the use of NIV in various other presentations of acute respiratory failure. It is important not only to know when to initiate NIV, but also when this therapy is failing. Whether NIV in the setting of acute respiratory failure can be managed appropriately outside the ICU setting is controversial. Although a variety of interfaces are available, the oronasal mask is the best initial interface in terms of leak prevention and patient comfort. Some critical care ventilators have NIV modes that compensate well for leaks, but as a group the ventilators that are designed specifically for NIV have better leak compensation. NIV should be part of the armamentarium of all clinicians caring from patients with acute respiratory failure.

Respiratory Care year in review 2012: invasive mechanical ventilation, noninvasive ventilation, and cystic fibrosis

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 invasive mechanical ventilation, noninvasive ventilation, and cystic fibrosis. These topics were chosen and reviewed in a manner that is most likely to have interest to the readers of Respiratory Care.

Respiratory therapy organizational changes are associated with increased respiratory care utilization

BACKGROUND

The effect of the respiratory therapist (RT)/patient ratio and RT organizational factors on respiratory resource utilization is unknown. We describe the impact of a multi-component intervention that called for an increase in RT/patient ratio (1:14 to 1:10), improved RT orientation, and formation of a core staffing model on best practice, including spontaneous breathing trials (SBTs) and catheter and bronchoscopically directed lower respiratory tract cultures, or bronchoalveolar lavage (BAL), in both ventilated and non-ventilated patients in the ICU.

METHODS

We conducted a single center, quasi-experimental study comparing 651 patients with single and first admissions between April 19, 2005 and April 18, 2006 before the RT services reorganization with 1,073 patients with single and first admissions between September 16, 2007 and September 4, 2008. Baseline characteristics were compared, along with SBTs, BAL use, lower respiratory tract cultures, and chest physiotherapy.

RESULTS

Patients in the 2 groups were similar in terms of age (52.9 ± 15.8 y vs 53.9 ± 16.4 y, P = .23), comorbidity as measured by Charlson score (2.8 ± 2.6 vs 2.8 ± 2.7, P = .56), and acuity of illness as measured by the Case Mix Index (3.2 ± 3.9 vs 3.3 ± 4.1, P = .47). Mechanically ventilated patients had similar prevalences of respiratory diseases (24.2% vs 25.1%, P = .61). There was an increase in SBTs (0.5% vs 73.1%, P < .001), chest physiotherapy (7.4% vs 21.6%, P < .001), BALs (24.0% vs 41.4%, P < .001), and lower respiratory tract cultures (21.5% vs 38.0%, P < .001) in mechanically ventilated patients post-intervention.

CONCLUSIONS

A multi-component intervention, including an increase in RT/patient ratio, improved RT orientation, and establishment of a core staffing model, was associated with increased respiratory resource utilization and evidence-based practice, specifically BALs and SBTs.

Tracheostomy tube change before day 7 is associated with earlier use of speaking valve and earlier oral intake

BACKGROUND

Presence of a tracheostomy tube often decreases the patient's ability to communicate and to tolerate oral intake. The initial tracheostomy tube change is often recommended between day 7 and 14 post insertion. Local guidelines permit tracheostomy tube change 5 days after insertion.

OBJECTIVE

We hypothesized that changing tracheostomy tubes before day 7 is associated with earlier use of a speaking valve as well as earlier oral intake, compared to changing tracheostomy tubes after 7 days.

METHODS

We prospectively enrolled 130 admitted subjects, after tracheostomy placement to a respiratory care unit between July 2008 and May 2010. Subject data were recorded from the electronic medical record. The primary end point was the time from tracheostomy tube placement to tolerating speaking valve. The secondary end point was the time from tracheostomy tube placement to tolerating oral intake. Complications of tracheostomy tube change were recorded.

RESULTS

Thirty-eight subjects had the first tracheostomy tube change before 7 days (early group), and 92 subjects had the first tracheostomy tube change after 7 days (late group). The early group tolerated a speaking valve significantly sooner than the late group (7 d vs 12 d, P = .001). The early group also tolerated oral intake significantly sooner (10 d vs 20 d, P = .04). After change of the tracheostomy tube, the time to tolerating oral feeding was 5.5 days in both groups. There was no significant difference in time to decannulation between the groups. The early group had a shorter respiratory care unit stay (11 d vs 17 d, P = .001) and a shorter hospital stay (P = .05) than the late group. There was no difference in survival. There were no complications associated with tracheostomy tube change.

CONCLUSIONS

Tracheostomy tube change before day 7 is associated with earlier ability to tolerate speaking valve and oral intake. In this series, early tracheostomy tube change was not associated with an increased rate of complications.

Developing a new, national approach to surveillance for ventilator-associated events

This article is an executive summary of a report from the Centers for Disease Control and Prevention Ventilator-Associated Pneumonia Surveillance Definition Working Group, entitled "Developing a New, National Approach to Surveillance for Ventilator-Associatied Events," published in Critical Care Medicine, by Magill SS, Klompas M, Balk R, Burns SM, Deutschman CS, et al. 2013;41(11):2467-2475. The full report provides a comprehensive description of the Working Group's process and outcome.