Examination of patterns in intubation by an emergency airway team at a large academic center: higher frequency during daytime hours

BACKGROUND

Emergency airway management represents an event with high acuity but unpredictable frequency and therefore presents a challenge for adequate staffing. Given circadian and seasonal variations, we hypothesized that the majority of emergency airway events happen after normal working hours and during the winter months.

METHODS

A retrospective analysis of 1,482 intubations by an emergency airway team over a 3-y period was performed. The data were obtained from hospitalized patients who required emergency airway management in a large academic medical center. A database of emergency airway consultations was analyzed for intubation time and date information, as well as geographic location within the hospital.

RESULTS

A greater percentage of emergency intubations occurred during day shift hours (7 am to 7 pm) compared with night shift hours, 57% and 43%, respectively (P < .01). The monthly frequency of intubations was not uniformly distributed across the year (P < .01). The greatest percentage of intubations was performed in February (10.9%), with the lowest being recorded in August (4.7%).

CONCLUSIONS

Emergency airway service utilization is highest during daytime hours, with seasonal variations composed of higher consults in the winter and lower consults in the summer.

Science and evidence: separating fact from fiction

Evidence-based medicine (EBM) is the integration of individual clinical expertise with the best available research evidence from systematic research and the patient's values and expectations. A hierarchy of evidence can be used to assess the strength upon which clinical decisions are made. The efficient approach to finding the best evidence is to identify systematic reviews or evidence-based clinical practice guidelines. Respiratory therapies that evidence supports include noninvasive ventilation for appropriately selected patients, lung-protective ventilation, and ventilator discontinuation protocols. Evidence does not support use of weaning parameters, albuterol for ARDS, and high frequency oscillatory ventilation for adults. Therapy with equivocal evidence includes airway clearance, selection of an aerosol delivery device, and PEEP for ARDS. Although all tenets of EBM are not universally accepted, the principles of EBM nonetheless provide a valuable approach to respiratory care practice.

A 5-year observational study of lung-protective ventilation in the operating room: a single-center experience

PURPOSE

We assessed the evolution of lung-protective ventilation strategies during anesthesia and identified factors associated with the selection of a nonprotective ventilation strategy.

METHODS

This retrospective observational study covered a 5-year period from March 2006 to March 2011. It included 45575 adult patients who underwent intubation de novo in the operating room. We considered a tidal volume (VT) greater than 10 mL/kg of ideal body weight (IBW) and/or positive end-expiratory pressure (PEEP) less than 5 cm H2O as not lung protective. We evaluated the use of nonprotective ventilation strategies over time in men and women, by American Society of Anesthesiologists classification, and for elective vs emergent surgery.

RESULTS

Over the duration of the study, there was a significant reduction in the percentage of patients receiving a VT greater than 10 mL/kg IBW (28.5%-16.3%, P < .001), zero PEEP (27.5%-18.2%, P < .001), and VT greater than 10 mL/kg IBW with PEEP less than 5 cm H2O (13.4%-8.0%, P < .001). The odds of receiving nonprotective ventilation were greater for women than for men, in the first year compared with the last year, and for elective compared with emergent surgery.

CONCLUSION

Although use of nonprotective ventilation decreased over time, an important percentage of patients continue to receive nonprotective ventilation.

Respiratory care year in review 2010: part 2. Invasive mechanical ventilation, noninvasive ventilation, pediatric mechanical ventilation, aerosol therapy

The purpose of this paper is to review the recent literature related to invasive mechanical ventilation, NIV, pediatric mechanical ventilation, and aerosol therapy. Topics covered related to invasive mechanical ventilation topics include the role of PEEP in providing lung protection during mechanical ventilation, unconventional modes for severe hypoxemia, and strategies to improve patient-ventilator interactions. Topics covered related to NIV include real-life NIV use, NIV and extubation failure, and NIV and pandemics. For pediatric mechanical ventilation, the topics addressed are NIV, invasive respiratory support, and inhaled nitric oxide. Topics covered related to aerosol therapy include short-acting β-adrenergic agents, long-acting β-adrenergic agents, long-acting antimuscarinic agents, inhaled corticosteroid therapy, phosphodiesterase type 4 (PDE4) inhibitors, long-acting β-adrenergic plus inhaled corticosteroid, long-acting antimuscarinic plus inhaled corticosteroid, nebulized hypertonic saline, inhaled mannitol, and inhaled antibiotic therapy. These topics were chosen and reviewed in a manner that is most likely to have interest to the readers of Respiratory Care.

Respiratory care year in review 2010: part 1. asthma, COPD, pulmonary function testing, ventilator-associated pneumonia

The purpose of this paper is to review the recent literature related to asthma, COPD, pulmonary function testing, and ventilator-associated pneumonia. Topics covered related to asthma include genetics and epigenetics; exposures; viruses; diet, obesity and exercise; exhaled nitric oxide; and drug therapy (β agonists, macrolides, tiotropium and monteleukast). Topics covered related to COPD include childhood disadvantage factors and COPD; vitamin D deficiency and COPD; β-blockers and COPD; corticosteroid therapy during COPD exacerbations; oxygen administration during pre-hospital transport of patients with COPD exacerbation; and prognosis of patients admitted to the hospital for COPD exacerbation. Topics related to pulmonary function testing include methods and techniques; predicted values; natural history, pulmonary function in health and disease; and the COPD controversy. Finally, the paper includes the following topics related to ventilator-associated pneumonia: the tube, the intubation route, and the cuff; mechanical ventilation; the bundle; and cost. These topics were chosen and reviewed in a manner that is most likely to have interest to the readers of Respiratory Care.

Patient-ventilator interaction during noninvasive ventilation

There is arguably more evidence to support the use of noninvasive ventilation (NIV) than any other practice related to the care of patients with acute respiratory failure. Despite this strong evidence base, NIV seems to be under-utilized and the failure rate (need for intubation) may be as high as 40%. Some of these failures potentially relate to asynchrony, although the relationship between asynchrony and NIV failure has not been well studied. Good NIV tolerance has been associated with success of NIV, and improved comfort has been associated with better synchrony. In one study a high rate of asynchrony occurred in 43% of patients during NIV. Asynchrony is commonly associated with leaks. Thus, reducing the leak related to the interface and using a ventilator with good leak compensation should reduce the rate of asynchrony. Asynchronies can also be related to the underlying disease process. This paper reviews issues related to asynchrony during NIV and suggests strategies that might be used to correct asynchrony when it occurs.

The value of adding a verbal report to written handoffs on early readmission following prolonged respiratory failure

Patients who survive the acute phase of respiratory failure often are transferred to units with specialized expertise. These patients have a high risk of being readmitted to the acute care hospital. We conducted this study to determine whether supplementing a written report with a verbal telephone report reduces readmission rates within the first 72 h after discharge and decreases hospital costs. The study design was observational with a historical control group that included patients admitted to our respiratory acute care unit between November 2003 and October 2005. In November 2005, we implemented a strategy in which a written report at discharge was supplemented with a telephone report by the physician or nurse practitioner, nurse, and respiratory therapist. The intervention group began in November 2005 and continued through October 2007. The primary end point was readmission to Massachusetts General Hospital within 72 h of discharge. We also determined the cost related to readmission. The study included 362 patients. The OR for readmission if the handoff included a verbal report was 0.42 (95% CI, 0.17-1.04). The total hospital cost was significantly lower in the group where verbal report was used ($111,723 vs $148,574; P = .002). Supplementing a written report with a verbal telephone report was associated with a significant reduction in cost and an average savings of ∼ $184,000 for every 100 patients discharged, representing added value in delivered care.

Evidence-based clinical practice guideline: inhaled nitric oxide for neonates with acute hypoxic respiratory failure

Inhaled nitric oxide (INO) is a colorless, odorless gas that is also a potent pulmonary vasodilator. When given via the inhaled route it is a selective pulmonary vasodilator. INO is approved by the United States Food and Drug Administration (FDA) for the treatment of term and near-term neonates with hypoxemic respiratory failure associated with clinical or echocardiographic evidence of pulmonary arterial hypertension. A systematic review of the literature was conducted with the intention of making recommendations related to the clinical use of INO for its FDA-approved indication. Specifically, we wrote these evidence-based clinical practice guidelines to address the following questions: (1) What is the evidence for labeled use? (2) What are the specific indications for INO for neonates with acute hypoxemic respiratory failure? (3) Does the use of INO impact oxygenation, mortality, or utilization of extracorporeal membrane oxygenation (ECMO)? (4) Does INO affect long-term outcomes? (5) Is INO cost-effective therapy? (6) How is the appropriate dosing regimen and dose response to INO established? (7) How is the dose of INO titrated and weaned? (8) Which INO delivery system should be used? (9) How should INO be implemented with different respiratory support devices? (10) What adverse effects of INO should be monitored, and at what frequency? (11) What physiologic parameters should be monitored during INO? (12) Is scavenging of gases necessary to protect the caregivers? Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scoring system, 22 recommendations are developed for the use of INO in newborns.

Severe hypoxemic respiratory failure: part 1--ventilatory strategies

Approximately 16% of deaths in patients with ARDS results from refractory hypoxemia, which is the inability to achieve adequate arterial oxygenation despite high levels of inspired oxygen or the development of barotrauma. A number of ventilator-focused rescue therapies that can be used when conventional mechanical ventilation does not achieve a specific target level of oxygenation are discussed. A literature search was conducted and narrative review written to summarize the use of high levels of positive end-expiratory pressure, recruitment maneuvers, airway pressure-release ventilation, and high-frequency ventilation. Each therapy reviewed has been reported to improve oxygenation in patients with ARDS. However, none of them have been shown to improve survival when studied in heterogeneous populations of patients with ARDS. Moreover, none of the therapies has been reported to be superior to another for the goal of improving oxygenation. The goal of improving oxygenation must always be balanced against the risk of further lung injury. The optimal time to initiate rescue therapies, if needed, is within 96 h of the onset of ARDS, a time when alveolar recruitment potential is the greatest. A variety of ventilatory approaches are available to improve oxygenation in the setting of refractory hypoxemia and ARDS. Which, if any, of these approaches should be used is often determined by the availability of equipment and clinician bias.

Are inhaled vasodilators useful in acute lung injury and acute respiratory distress syndrome?

In patients with acute respiratory distress syndrome (ARDS), inhaled vasodilator can result in important physiologic benefits (eg, improved hypoxemia, lower pulmonary arterial pressure, and improved right-ventricular function and cardiac output) without systemic hemodynamic effects. Inhaled nitric oxide (INO) and aerosolized prostacyclins are currently the most frequently used inhaled vasodilators. Inhaled prostacyclins are as effective physiologically as INO and cost less. Randomized controlled trials of INO in the treatment of ARDS have shown short-term physiologic benefits, but no benefit in long-term outcomes. No outcome studies have been reported on the use of prostacyclin in patients with ARDS. There is no role for the routine use of inhaled vasodilators in patients with ARDS. Inhaled vasodilator as a rescue therapy for severe refractory hypoxemia in patients with ARDS may be reasonable, but is controversial.

A North American survey of respiratory therapist and physician tracheostomy decannulation practices

BACKGROUND

Tracheostomy is a common surgical procedure performed on critically ill patients. However, little is known about how clinicians make decisions to decannulate patients, and whether similar decisions are made by respiratory therapists (RTs) and physicians.

METHODS

We performed a cross-sectional survey of RTs (n = 52) and physicians (n = 102) at 54 medical centers in North America, to characterize contemporary decannulation practices.

RESULTS

RTs and physicians rated ability to tolerate capping, secretions, cough effectiveness, and level of consciousness as the most important factors in the decannulation decision, with RTs placing greater emphasis on ability to tolerate capping and physicians on level of consciousness. In the clinical scenarios, RTs and physicians recommended decannulation with similar frequency (52% vs 55%, P = .54). Patients were most likely to be recommended for decannulation if they had a strong cough, scant thin secretions, required minimal supplemental oxygen, and were alert and interactive. In addition, RTs were more likely to recommend decannulation for patients who demonstrated an ability to tolerate tracheostomy tube capping for 72 hours and whose etiology of respiratory failure was chronic obstructive pulmonary disease. RTs preferred shorter time frames for defining decannulation failure than did physicians (median response 48 h vs 96 h, P = .02 for test of proportions). Both groups identified 2-5% (median response) as an acceptable rate of decannulation failure (P = .48 for test of proportions).

CONCLUSIONS

Important differences exist in the decannulation practices of North American RTs and physicians. Evidence-based tracheostomy guidelines are needed to facilitate the safe and effective management of patients with tracheostomies.

A survey of the use of noninvasive ventilation in academic emergency departments in the United States

OBJECTIVE

To determine the frequency of, and barriers to, use of noninvasive ventilation (NIV) for adult patients with acute asthma, chronic obstructive pulmonary disease (COPD), and congestive heart failure (CHF) in academic emergency departments (EDs).

METHODS

A survey instrument was developed by the authors, pilot tested, and distributed to one physician (MD) and one respiratory therapist (RT) at the 132 hospitals with emergency medicine residencies.

RESULTS

The response rate was 90%. Ninety-nine percent of RTs and 64% of MDs are very familiar with NIV (P<.001). The reported time needed to initiate NIV was <10 min for 41% of sites (<20 min for 89%). Compared to the time requirement in other clinical areas, 60% of RTs reported that NIV "takes no additional time" in the ED. An RT is always present in 38% the EDs, and equipment for NIV is readily available in 76% of the EDs. The majority reported that NIV use is about right for acute COPD, CHF, and asthma. NIV is used infrequently for asthma (89% reported use in <20% of these patients), while 66% reported use in >20% of COPD patients and 67% reported use in >20% of CHF patients (P<.001, as compared to asthma). The perceived utility of NIV was significantly different between the 3 diagnoses (P<.001); there was more uncertainty about the utility of NIV for asthma. Bilevel ventilators and oronasal masks are most commonly used for NIV. Nearly all of the centers administer bronchodilators in-line with NIV.

CONCLUSIONS

Consistent with available evidence, NIV use is more common in the ED for acute COPD and CHF than for acute asthma. Barriers to greater use of NIV in the ED include physician familiarity, availability of RT and equipment in the ED, and time required for NIV. For acute asthma, uncertainty about therapeutic benefits remains a challenge.

How to initiate a noninvasive ventilation program: bringing the evidence to the bedside

Noninvasive ventilation (NIV) is under-utilized, despite robust evidence supporting its use in appropriately selected patients with acute respiratory failure. Diffusion of NIV into practice requires that clinicians view it as better than invasive ventilation, that it is perceived as compatible with existing approaches to mechanical ventilation, that it is not too difficult to apply, that it is trialable, and that its results are visible. Barriers to NIV use include lack of awareness of the evidence, lack of agreement with the evidence, lack of self-efficacy, unrealistic outcome expectations, and the inertia of previous practice. A flexible, tireless, enthusiastic, and knowledgeable clinical champion is important when initiating an NIV program. Knowledge and training are also important; ideally the training should be one-on-one and hands-on to the extent possible. Adequate personnel and equipment resources are necessary when implementing the program. Guidelines and protocols may be useful as educational resources, to avoid clinical conflict and consolidate authority. When initiating an NIV program it is important to recognize that NIV does not avoid intubation in all cases. Success often improves with experience. The available evidence suggests that NIV is cost-effective. For optimum success the multidisciplinary nature of NIV application must be recognized. The NIV program should be a quality-improvement initiative. Following these principles, a successful program can be initiated in any acute-care setting.

Do newer monitors of exhaled gases, mechanics, and esophageal pressure add value?

The current understanding of lung mechanics and ventilator-induced lung injury suggests that patients who have acute respiratory distress syndrome should be ventilated in such a way as to minimize alveolar over-distension and repeated alveolar collapse. Clinical trials have used such lung protective strategies and shown a reduction in mortality; however, there is data that these "one-size fits all" strategies do not work equally well in all patients. This article reviews other methods that may prove useful in monitoring for potential lung injury: exhaled breath condensate, pressure-volume curves, and esophageal manometry. The authors explore the concepts, benefits, difficulties, and relevant clinical trials of each.

The chest wall in acute lung injury/acute respiratory distress syndrome

PURPOSE OF REVIEW

There has recently been renewed interest in the chest wall during mechanical ventilation, related to lung-protective ventilation strategies, as well as in the role of abdominal pressure in many facets of critical illness. The purpose of this review is to address relevant issues related to the chest wall and mechanical ventilation, particularly in patients with acute lung injury/acute respiratory distress syndrome.

RECENT FINDINGS

In mechanically ventilated patients with acute lung injury, intra-abdominal pressure is an important determinant of chest wall compliance. With elevated intra-abdominal pressure, the compliance of the chest wall and total respiratory system is decreased, with a relatively normal compliance of the lungs. The lung compression effects of increased intra-abdominal pressure may lead to a loss of lung volume with atelectasis. An appropriate level of positive end-expiratory pressure is necessary to counterbalance this collapsing effect on the lungs. Also, the stiff chest wall results in a lower transpulmonary pressure during positive-pressure ventilation.

SUMMARY

As chest wall compliance may have important clinical implications during positive-pressure ventilation, the physiology of this effect should be considered, particularly in patients with acute lung injury and increased abdominal pressure.

Aerosol delivery devices in the treatment of asthma

Nebulizers convert solutions or suspensions into aerosols with a particle size that can be inhaled into the lower respiratory tract. There are pneumatic jet nebulizers, ultrasonic nebulizers, and mesh nebulizers. Newer nebulizer designs are breath-enhanced, breath-actuated, or have aerosol-storage bags to minimize aerosol loss during exhalation. Nebulizers can be used with helium-oxygen mixture and can be used for continuous aerosol delivery. Increased attention has recently been paid to issues related to the use of a facemask with a nebulizer. The pressurized metered-dose inhaler (pMDI) is a very commonly used device for aerosol delivery. There are press-and-breathe and breath-actuated pMDI designs. Issues related to pMDIs that have received increasing attention are the conversion to hydrofluoroalkane propellant and the use of dose counters. Many patients have poor pMDI technique. Valved holding chambers and spacers are used to improve pMDI technique and to decrease aerosol deposition in the upper airway. In recent years increasing attention has been paid to the issues of electrostatic charge and facemasks related to valved holding chambers. Many newer formulations for inhalation have been released in dry-powder inhalers, which are either unit-dose or multi-dose inhalers. Systematic reviews and meta-analyses have suggested that each of these aerosol delivery devices can work equally well in patients who can use them correctly. However, many patients use these devices incorrectly, so proper patient education in their use is critical.