The accuracy of the bedside swallowing evaluation for detecting aspiration in survivors of acute respiratory failure.

BACKGROUND: Dysphagia with subsequent aspiration occurs in up to 60% of acute respiratory failure (ARF) survivors. Accurate bedside tests for aspiration can reduce aspiration-related complications while minimizing delay of oral nutrition. In a cohort of ARF survivors, we determined the accuracy of the bedside swallowing evaluation (BSE) and its components for detecting aspiration. METHODS: Patients who were extubated after at least 24hours of mechanical ventilation were eligible for enrollment. Within 3 days of extubation, patients underwent comprehensive BSE including 3-oz water swallowing test (3-WST), followed by a criterion standard test for aspiration, flexible endoscopic evaluation of swallowing (FEES). RESULTS: Forty-five patients were included in the analysis. Median patient age was 55years (interquartile range, 47-65). Median duration of mechanical ventilation was 3.3days (interquartile range 1.8-6.0). Fourteen patients (31%) aspirated on FEES. Physical examination findings on BSE and abnormal swallowing during trials of different consistencies were variably associated with aspiration. Compared with FEES, the 3-WST yielded a sensitivity of 77% (95% confidence interval [CI], 50%-92%), specificity of 65% (95% CI, 47%-79%), and an area under the receiver operating characteristic curve (AUC) of 0.71; a speech language pathologist's recommendation for altered diet yielded a sensitivity of 86% (95% CI, 60%-96%), a specificity of 52% (95% CI, 35%-68%), and an AUCof 0.69; an speech language pathologist's recommendation for nil per os (nothing by mouth) yielded a sensitivity of 50% (95% CI, 27%-73%), a specificity of 94% (95% CI, 79%-98%), and an AUCof 0.72. CONCLUSIONS: The BSE and its components, including the 3-WST, demonstrated variable accuracy for aspiration in survivors of ARF. Investigation to determine the optimal noninvasive test for aspiration in ARF survivors is warranted. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov identifier: NCT02363686, Aspiration in Acute Respiratory Failure Survivors.

Swallowing dysfunction after critical illness.

Critical care practitioners must frequently make decisions about their patients' ability to swallow food, liquids, and pills. These decisions can be particularly difficult given the incompletely defined epidemiology, diagnostic criteria, and prognostic features of swallowing disorders in critically ill patients. Furthermore, the consequences of improper decisions-namely, aspiration, malnutrition, hunger, and thirst-can be devastating to patients and their families. This review outlines the problem of swallowing dysfunction in critically ill patients and then addresses the most clinically relevant questions that critical care practitioners face today. First, we review the epidemiology of swallowing dysfunction in critically ill patients. Next, we describe the different diagnostic tests for swallowing dysfunction and describe a general approach to the initial assessment for swallowing disorders. Finally, we explore the existing treatments for swallowing dysfunction. Given the burden of swallowing dysfunction in patients recovering from critical illness, enabling critical care practitioners to manage these disorders, while stimulating new investigation into their pathophysiology, diagnosis, and management, will enhance our care of critically ill patients.

Screening for critical illness polyneuromyopathy with single nerve conduction studies.

PURPOSE: The ability to diagnose patients with critical illness polyneuromyopathy (CIPNM) is hampered by impaired patient sensorium, technical limitations, and the time-intensive nature of performing electrophysiological testing. Therefore, we sought to determine whether single nerve conduction studies (NCS) could accurately screen for CIPNM. METHODS: Critically ill patients at increased risk for developing CIPNM were identified. Bilateral NCS of six nerves, and concentric needle electromyography were performed within 24 h of meeting inclusion criteria, and subsequently on a weekly basis until CIPNM was diagnosed or the patient was discharged from the intensive care unit (ICU). RESULTS: A total of 75 patients were enrolled into the study. Patients who developed CIPNM had a higher hospital mortality (50 vs. 13%, p = 0.002), and fewer ICU-free days (0 vs. 11, p = 0.04). There were no differences between the right and left amplitudes (p = 0.59, 0.91, and 0.21) for nerves that could be simultaneously tested bilaterally (sural, peroneal, and tibial). The amplitudes for each of the six individual nerves were significantly diminished in patients with CIPNM when compared to patients without CIPNM. The nerves with the best diagnostic accuracy were the peroneal nerve [AUC = 0.8856; sensitivity = 94% (95% CI = 88-100%); specificity = 74% (95% CI = 63-85%)], and the sural nerve [AUC = 0.8611; sensitivity = 94% (95 % CI = 88-100%); specificity = 70% (95 % CI = 59-81%)]. The combined diagnostic accuracy for the amplitudes of the peroneal and sural nerves increased significantly [AUC = 0.9336; sensitivity = 100% (95% CI = 100-100%) and specificity = 81% (95% CI = 71-91%)]. CONCLUSIONS: Unilateral peroneal and sural NCS can accurately screen for CIPNM in ICU patients and detect a limited number of patients that would need concentric needle electromyography to confirm a diagnosis of CIPNM. These results identify a more streamlined method to diagnose CIPNM that may facilitate routine diagnostic testing and monitoring of weakness in critically ill patients.

ICU-acquired swallowing disorders.

OBJECTIVES: Patients hospitalized in the ICU can frequently develop swallowing disorders, resulting in an inability to effectively transfer food, liquids, and pills from their mouth to stomach. The complications of these disorders can be devastating, including aspiration, reintubation, pneumonia, and a prolonged hospital length of stay. As a result, critical care practitioners should understand the optimal diagnostic strategies, proposed mechanisms, and downstream complications of these ICU-acquired swallowing disorders. DATA SOURCES: Database searches and a review of the relevant medical literature. DATA SYNTHESIS: A significant portion of the estimated 400,000 patients who annually develop acute respiratory failure, require endotracheal intubation, and survive to be extubated are determined to have dysfunctional swallowing. This group of swallowing disorders has multiple etiologies, including local effects of endotracheal tubes, neuromuscular weakness, and an altered sensorium. The diagnosis of dysfunctional swallowing is usually made by a speech-language pathologist using a bedside swallowing evaluation. Major complications of swallowing disorders in hospitalized patients include aspiration, reintubation, pneumonia, and increased hospitalization. The national yearly cost of swallowing disorders in hospitalized patients is estimated to be over $500 million. Treatment modalities focus on changing the consistency of food, changing mealtime position, and/or placing feeding tubes to prevent aspiration. CONCLUSIONS: Swallowing disorders are costly and clinically important in a large population of ICU patients. The development of effective screening strategies and national diagnostic standards will enable further studies aimed at understanding the precise mechanisms for these disorders. Further research should also concentrate on identifying modifiable risk factors and developing novel treatments aimed at reducing the significant burden of swallowing dysfunction in critical illness survivors.

Post-extubation dysphagia is associated with longer hospitalization in survivors of critical illness with neurologic impairment.

INTRODUCTION: Critically ill patients can develop acute respiratory failure requiring endotracheal intubation. Swallowing dysfunction after liberation from mechanical ventilation, also known as post-extubation dysphagia, is common and deleterious among patients without neurologic disease. However, the risk factors associated with the development of post-extubation dysphagia and its effect on hospital lengthofstay in critically ill patients with neurologic disorders remains relatively unexplored. METHODS: We conducted a retrospective, observational cohort study from 2008 to 2010 of patients with neurologic impairment who required mechanical ventilation and subsequently received a bedside swallow evaluation (BSE) by a speech-language pathologist. RESULTS: A BSE was performed after mechanical ventilation in 25% (630/2,484) of all patients. In the 184 patients with neurologic impairment, post-extubation dysphagia was present in 93% (171/184), and was classified as mild, moderate, or severe in 34% (62/184), 26% (48/184), and 33% (61/184), respectively. In univariate analyses, statistically significant risk factors for moderate/severe dysphagia included longer durations of mechanical ventilation and the presence of a tracheostomy. In multivariate analysis, adjusting for age, tracheostomy, cerebrovascular disease, and severity of illness, mechanical ventilation for >7 days remained independently associated with moderate/severe dysphagia (adjusted odds ratio=4.48 (95%confidence interval=2.14 to 9.81), P<0.01). The presence of moderate/severe dysphagia was also significantly associated with prolonged hospital lengthofstay, discharge status, and surgical placement of feeding tubes. When adjusting for age, severity of illness, and tracheostomy, patients with moderate/severe dysphagia stayed in the hospital 4.32 days longer after their initial BSE than patients with none/mild dysphagia (95% confidence interval=3.04 to 5.60 days, P<0.01). CONCLUSION: In a cohort of critically ill patients with neurologic impairment, longer duration of mechanical ventilation is independently associated with post-extubation dysphagia, and the development of post-extubation dysphagia is independently associated with a longer hospital length of stay after the initial BSE.

Healthcare utilization in medical intensive care unit survivors with alcohol withdrawal.

BACKGROUND: Rehospitalization is an important and costly outcome that occurs commonly in several diseases encountered in the medical intensive care unit (ICU). Although alcohol use disorders are present in 40% of ICU survivors and alcohol withdrawal is the most common alcohol-related reason for admission to an ICU, rates and predictors of rehospitalization have not been previously reported in this population. METHODS: We conducted a retrospective cohort study of medical ICU survivors with a primary or secondary discharge diagnosis of alcohol withdrawal using 2 administrative databases. The primary outcome was time to rehospitalization or death. Secondary outcomes included time to first emergency department or urgent care clinic visit in the subset of ICU survivors who were not rehospitalized. Cox proportional hazard models were adjusted for age, gender, race, homelessness, smoking, and payer source. RESULTS: Of 1,178 patients discharged from the medical ICU over the study period, 468 (40%) were readmitted to the hospital and 54 (4%) died within 1 year. Schizophrenia (hazard ratio 2.23, 95% CI 1.57, 3.34, p < 0.001), anxiety disorder (hazard ratio 2.04, 95% CI 1.30, 3.32, p < 0.01), depression (hazard ratio 1.62, 95% CI 1.05, 2.40, p = 0.03), and Deyo comorbidity score ≥3 (hazard ratio 1.43, 95% CI 1.09, 1.89, p = 0.01) were significant predictors of time to death or first rehospitalization. Bipolar disorder was associated with time to first emergency department or urgent care clinic visit (hazard ratio 2.03, 95% CI 1.24, 3.62, p < 0.01) in the 656 patients who were alive and not rehospitalized within 1 year. CONCLUSIONS: The presence of a psychiatric comorbidity is a significant predictor of multiple measures of unplanned healthcare utilization in medical ICU survivors with a primary or secondary discharge diagnosis of alcohol withdrawal. This finding highlights the potential importance of targeting longitudinal multidisciplinary care to patients with a dual diagnosis.

Growth differentiation factor-15 and prognosis in acute respiratory distress syndrome: a retrospective cohort study.

INTRODUCTION: We sought to determine whether higher levels of the novel biomarker growth differentiation factor-15 (GDF-15) are associated with poor outcomes and the presence of pulmonary vascular dysfunction (PVD) in patients with acute respiratory distress syndrome (ARDS). METHODS: We conducted a retrospective cohort study in patients enrolled in the Acute Respiratory Distress Syndrome Network Fluid and Catheter Treatment (FACT) Trial. Patients enrolled in the FACT Trial who received a pulmonary artery catheter (PAC), had plasma available from the same study day and sufficient hemodynamic data to determine the presence of PVD were included. Logistic regression was used to determine the association between GDF-15 level and 60-day mortality. RESULTS: Of the 513 patients enrolled in the FACT Trial assigned to receive a PAC, 400 were included in this analysis. Mortality at 60 days was significantly higher in patients whose GDF-15 levels were in the third (28%) or fourth (49%) quartile when compared to patients with GDF-15 levels in the first quartile (12%) (P <0.001). Adjusting for severity of illness measured by APACHE III score, the odds of death for patients with GDF-15 levels in the fourth quartile when compared to the first quartile was 4.26 (95% CI 2.18, 10.92, P <0.001). When added to APACHE III alone for prediction of 60-day mortality, GDF-15 levels increased the area under the receiver operating characteristic curve from 0.72 to 0.77. At an optimal cutoff of 8,103 pg/mL, the sensitivity and specificity of GDF-15 for predicting 60-day mortality were 62% (95% CI 53%, 71%) and 76% (95% CI 71%, 81%), respectively. Levels of GDF-15 were not useful in identifying the presence of PVD, as defined by hemodynamic measurements obtained by a PAC. CONCLUSIONS: In patients with ARDS, higher levels of GDF-15 are significantly associated with poor outcome but not PVD.

Alcohol screening scores and 90-day outcomes in patients with acute lung injury.

OBJECTIVES: The effects of excess alcohol consumption (alcohol misuse) on outcomes in patients with acute lung injury have been inconsistent, and there are no studies examining this association in the era of low tidal volume ventilation and a fluid conservative strategy. We sought to determine whether validated scores on the Alcohol Use Disorders Identification Test that correspond to past-year abstinence (zone 1), low-risk drinking (zone 2), mild to moderate alcohol misuse (zone 3), and severe alcohol misuse (zone 4) are associated with poor outcomes in patients with acute lung injury. DESIGN: Secondary analysis. SETTING: The Acute Respiratory Distress Syndrome Network, a consortium of 12 university centers (44 hospitals) dedicated to the conduct of multicenter clinical trials in patients with acute lung injury. SUBJECTS: Patients meeting consensus criteria for acute lung injury enrolled in one of three recent Acute Respiratory Distress Syndrome Network clinical trials. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 1,133 patients enrolled in one of three Acute Respiratory Distress Syndrome Network studies, 1,037 patients had an Alcohol Use Disorders Identification Test score available for analysis. Alcohol misuse was common with 70 (7%) of patients having Alcohol Use Disorders Identification Test scores in zone 3 and 129 (12%) patients in zone 4. There was a U-shaped association between validated Alcohol Use Disorders Identification Test zones and death or persistent hospitalization at 90 days (34% in zone 1, 26% in zone 2, 27% in zone 3, 36% in zone 4; p < 0.05 for comparison of zone 1 to zone 2 and zone 4 to zone 2). In a multiple logistic regression model, there was a significantly higher odds of death or persistent hospitalization in patients having Alcohol Use Disorders Identification Test zone 4 compared with those in zone 2 (adjusted odds ratio 1.70; 95% confidence interval 1.00, 2.87; p = 0.048). CONCLUSIONS: Severe but not mild to moderate alcohol misuse is independently associated with an increased risk of death or persistent hospitalization at 90 days in acute lung injury patients.

Diagnosis and treatment of post-extubation dysphagia: results from a national survey.

PURPOSE: This study sought to determine the utilization of speech-language pathologist (SLPs) for the diagnosis and treatment of post-extubation dysphagia in survivors of mechanical ventilation. METHODS: We designed, validated, and mailed a survey to 1,966 inpatient SLPs who routinely evaluate patients for post-extubation dysphagia. RESULTS: Most SLP diagnostic evaluations (60%; 95% CI, 59%-62%) were performed using clinical techniques with uncertain accuracy. Instrumental diagnostic tests (such as fluoroscopy and endoscopy) are more likely to be available at university than community hospitals. After adjusting for hospital size and academic affiliation, instrumental test use varied significantly by geographical region. Treatments for post-extubation dysphagia usually involved dietary adjustment (76%; 95% CI, 73-79%) and postural changes/compensatory maneuvers (86%; 95% CI, 84-88%), rather than on interventions aimed to improve swallowing function (24%; 95% CI, 21-27%). CONCLUSIONS: SLPs frequently evaluate acute respiratory failure survivors. However, diagnostic evaluations rely mainly upon bedside techniques with uncertain accuracy. The use of instrumental tests varies by geographic location and university affiliation. Current diagnostic practices and feeding decisions for critically ill patients should be viewed with caution until further studies determine the accuracy of bedside detection methods.

Medical student views on interactions with pharmaceutical representatives.

OBJECTIVE: In 2006, the Housestaff Association presented the Dean at Oregon Health and Science University (OHSU) with a proposal to effectively end the influence of the pharmaceutical industry on campus. The Dean convened a workgroup to examine the issue, and faculty, residents, and medical students were surveyed on their views and interactions. Authors present here the responses from medical students. METHODS: A web-based, anonymous survey was sent to all OHSU medical students in 2007; 59% completed it. The survey included items measuring attitudes about the pharmaceutical industry and interactions with pharmaceutical representatives (PRs). RESULTS: Only 5% of clinical and 7% of preclinical students agreed that PRs have an important teaching role, and fewer than 1 in 6 believed that PRs provided useful and accurate information on either new or established drugs; 54% of clinical students indicated that PRs should be restricted from making presentations on campus, versus 32% of preclinical students, and only 30% of clinical students agreed that accepting gifts had no impact on their own prescribing, versus 50% of preclinical students. Students who acknowledged the influence of PRs and perceived less educational benefit were less likely to accept gifts such as textbooks; however, 84% of clinical students had attended an on-campus event sponsored by a pharmaceutical company in the previous year. CONCLUSIONS: Only a small proportion of OHSU medical students value interactions with PRs, but many still attend events sponsored by pharmaceutical companies.

Postextubation dysphagia is persistent and associated with poor outcomes in survivors of critical illness.

INTRODUCTION: Dysphagia is common among survivors of critical illness who required mechanical ventilation during treatment. The risk factors associated with the development of postextubation dysphagia, and the effects of dysphagia on patient outcomes, have been relatively unexplored. METHODS: We conducted a retrospective, observational cohort study from 2008 to 2010 of all patients over 17 years of age admitted to a university hospital ICU who required mechanical ventilation and subsequently received a bedside swallow evaluation (BSE) by a speech pathologist. RESULTS: A BSE was performed after mechanical ventilation in 25% (630 of 2,484) of all patients. After we excluded patients with stroke and/or neuromuscular disease, our study sample size was 446 patients. We found that dysphagia was present in 84% of patients (n = 374) and classified dysphagia as absent, mild, moderate or severe in 16% (n = 72), 44% (n = 195), 23% (n = 103) and 17% (n = 76), respectively. In univariate analyses, we found that statistically significant risk factors for severe dysphagia included long duration of mechanical ventilation and reintubation. In multivariate analysis, after adjusting for age, gender and severity of illness, we found that mechanical ventilation for more than seven days remained independently associated with moderate or severe dysphagia (adjusted odds ratio (AOR) = 2.84 [interquartile range (IQR) = 1.78 to 4.56]; P < 0.01). The presence of severe postextubation dysphagia was significantly associated with poor patient outcomes, including pneumonia, reintubation, in-hospital mortality, hospital length of stay, discharge status and surgical placement of feeding tubes. In multivariate analysis, we found that the presence of moderate or severe dysphagia was independently associated with the composite outcome of pneumonia, reintubation and death (AOR = 3.31 [IQR = 1.89 to 5.90]; P < 0.01). CONCLUSIONS: In a large cohort of critically ill patients, long duration of mechanical ventilation was independently associated with postextubation dysphagia, and the development of postextubation dysphagia was independently associated with poor patient outcomes.

Neuromuscular blockade resistance during therapeutic hypothermia.

OBJECTIVE: To report a case of neuromuscular blockade resistance to multiple agents during therapeutic hypothermia and discuss possible mechanisms of this resistance. CASE SUMMARY: A 64-year-old man with stage IV non-small-cell lung cancer and respiratory distress developed cardiac arrest in the emergency department. The man was quickly resuscitated and treated with therapeutic hypothermia. A chest tube was inserted for pleural drainage of a large right-sided effusion that collapsed the right lung; this was unsuccessful in reinflating the lung. A bronchopleural fistula developed and independent lung ventilation was initiated due to persistent hypoxemia. Neuromuscular blockade was initiated after sedation and analgesia did not control shivering and was continued due to patient-ventilator dyssynchrony and persistent hypoxemia. Despite large doses of 3 different neuromuscular blocking agents and negligible response to train-of-four tests, clinical neuromuscular blockade, represented by ventilator synchrony, was not achieved until the patient was warmed. DISCUSSION: Resistance to neuromuscular blocking agents has been reported in critically ill patients. Our case of neuromuscular blockade resistance occurred in a patient treated with therapeutic hypothermia, which generally requires a dose reduction of neuromuscular blocking agents. Resistance to neuromuscular blockade was quickly reversed upon warming of the patient as patient-ventilator synchrony was achieved at lower neuromuscular blocking agent doses. CONCLUSIONS: Clinicians should be aware of a potential blunted response to neuromuscular blocking agents during therapeutic hypothermia and difficulty with paralysis monitoring since train-of-four response may correlate poorly with clinical neuromuscular blockade during hypothermia. Further research is needed to elucidate the mechanism of this interaction, identify patients at risk, and evaluate alternative strategies to neuromuscular blockade for controlling shivering in patients undergoing therapeutic hypothermia.

Use of subtractive hybridization for comprehensive surveys of prokaryotic genome differences.

Comparative bacterial genomics shows that even different isolates of the same bacterial species can vary significantly in gene content. An effective means to survey differences across whole genomes would be highly advantageous for understanding this variation. Here we show that suppression subtractive hybridization (SSH) provides high, representative coverage of regions that differ between similar genomes. Using Helicobacter pylori strains 26695 and J99 as a model, SSH identified approximately 95% of the unique open reading frames in each strain, showing that the approach is effective. Furthermore, combining data from parallel SSH experiments using different restriction enzymes significantly increased coverage compared to using a single enzyme. These results suggest a powerful approach for assessing genome differences among closely related strains when one member of the group has been completely sequenced.