Survival of COVID-19 Patients With Respiratory Failure is Related to Temporal Changes in Gas Exchange and Mechanical Ventilation.

Background: Respiratory failure due to coronavirus disease of 2019 (COVID-19) often presents with worsening gas exchange over a period of days. Once patients require mechanical ventilation (MV), the temporal change in gas exchange and its relation to clinical outcome is poorly described. We investigated whether gas exchange over the first 5 days of MV is associated with mortality and ventilator-free days at 28 days in COVID-19. Methods: In a cohort of 294 COVID-19 patients, we used data during the first 5 days of MV to calculate 4 daily respiratory scores: PaO2/FiO2 (P/F), oxygenation index (OI), ventilatory ratio (VR), and Murray lung injury score. The association between these scores at early (days 1-3) and late (days 4-5) time points with mortality was evaluated using logistic regression, adjusted for demographics. Correlation with ventilator-free days was assessed (Spearman rank-order coefficients). Results: Overall mortality was 47.6%. Nonsurvivors were older (P < .0001), more male (P = .029), with more preexisting cardiopulmonary disease compared to survivors. Mean PaO2 and PaCO2 were similar during this timeframe. However, by days 4 to 5 values for all airway pressures and FiO2 had diverged, trending lower in survivors and higher in nonsurvivors. The most substantial between-group difference was the temporal change in OI, improving 15% in survivors and worsening 11% in nonsurvivors (P < .05). The adjusted mortality OR was significant for age (1.819, P = .001), OI at days 4 to 5 (2.26, P = .002), and OI percent change (1.90, P = .02). The number of ventilator-free days correlated significantly with late VR (-0.166, P < .05), early and late OI (-0.216, P < .01; -0.278, P < .01, respectively) and early and late P/F (0.158, P < .05; 0.283, P < .01, respectively). Conclusion: Nonsurvivors of COVID-19 needed increasing intensity of MV to sustain gas exchange over the first 5 days, unlike survivors. Temporal change OI, reflecting both PaO2 and the intensity of MV, is a potential marker of outcome in respiratory failure due to COVID-19.

Deep learning prediction of likelihood of ICU admission and mortality in COVID-19 patients using clinical variables.

BACKGROUND: This study aimed to develop a deep-learning model and a risk-score system using clinical variables to predict intensive care unit (ICU) admission and in-hospital mortality in COVID-19 patients. METHODS: This retrospective study consisted of 5,766 persons-under-investigation for COVID-19 between 7 February 2020 and 4 May 2020. Demographics, chronic comorbidities, vital signs, symptoms and laboratory tests at admission were collected. A deep neural network model and a risk-score system were constructed to predict ICU admission and in-hospital mortality. Prediction performance used the receiver operating characteristic area under the curve (AUC). RESULTS: The top ICU predictors were procalcitonin, lactate dehydrogenase, C-reactive protein, ferritin and oxygen saturation. The top mortality predictors were age, lactate dehydrogenase, procalcitonin, cardiac troponin, C-reactive protein and oxygen saturation. Age and troponin were unique top predictors for mortality but not ICU admission. The deep-learning model predicted ICU admission and mortality with an AUC of 0.780 (95% CI [0.760-0.785]) and 0.844 (95% CI [0.839-0.848]), respectively. The corresponding risk scores yielded an AUC of 0.728 (95% CI [0.726-0.729]) and 0.848 (95% CI [0.847-0.849]), respectively. CONCLUSIONS: Deep learning and the resultant risk score have the potential to provide frontline physicians with quantitative tools to stratify patients more effectively in time-sensitive and resource-constrained circumstances.

Prediction model and risk scores of ICU admission and mortality in COVID-19.

This study aimed to develop risk scores based on clinical characteristics at presentation to predict intensive care unit (ICU) admission and mortality in COVID-19 patients. 641 hospitalized patients with laboratory-confirmed COVID-19 were selected from 4997 persons under investigation. We performed a retrospective review of medical records of demographics, comorbidities and laboratory tests at the initial presentation. Primary outcomes were ICU admission and death. Logistic regression was used to identify independent clinical variables predicting the two outcomes. The model was validated by splitting the data into 70% for training and 30% for testing. Performance accuracy was evaluated using area under the curve (AUC) of the receiver operating characteristic analysis (ROC). Five significant variables predicting ICU admission were lactate dehydrogenase, procalcitonin, pulse oxygen saturation, smoking history, and lymphocyte count. Seven significant variables predicting mortality were heart failure, procalcitonin, lactate dehydrogenase, chronic obstructive pulmonary disease, pulse oxygen saturation, heart rate, and age. The mortality group uniquely contained cardiopulmonary variables. The risk score model yielded good accuracy with an AUC of 0.74 ([95% CI, 0.63-0.85], p = 0.001) for predicting ICU admission and 0.83 ([95% CI, 0.73-0.92], p<0.001) for predicting mortality for the testing dataset. This study identified key independent clinical variables that predicted ICU admission and mortality associated with COVID-19. This risk score system may prove useful for frontline physicians in clinical decision-making under time-sensitive and resource-constrained environment.

Continued In-Hospital Angiotensin-Converting Enzyme Inhibitor and Angiotensin II Receptor Blocker Use in Hypertensive COVID-19 Patients Is Associated With Positive Clinical Outcome.

BACKGROUND: This study investigated continued and discontinued use of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARB) during hospitalization of 614 hypertensive laboratory-confirmed COVID-19 patients. METHODS: Demographics, comorbidities, vital signs, laboratory data, and ACEi/ARB usage were analyzed. To account for confounders, patients were substratified by whether they developed hypotension and acute kidney injury (AKI) during the index hospitalization. RESULTS: Mortality (22% vs 17%, P > .05) and intensive care unit (ICU) admission (26% vs 12%, P > .05) rates were not significantly different between non-ACEi/ARB and ACEi/ARB groups. However, patients who continued ACEi/ARBs in the hospital had a markedly lower ICU admission rate (12% vs 26%; P = .001; odds ratio [OR] = 0.347; 95% confidence interval [CI], .187-.643) and mortality rate (6% vs 28%; P = .001; OR = 0.215; 95% CI, .101-.455) compared to patients who discontinued ACEi/ARB. The odds ratio for mortality remained significantly lower after accounting for development of hypotension or AKI. CONCLUSIONS: These findings suggest that continued ACEi/ARB use in hypertensive COVID-19 patients yields better clinical outcomes.

Outcomes of Introducing a Mobile Interactive Learning Resource in a Large Medical School Course.

Mobile devices are an integral part of modern medical education, as convenient platforms for access to online interactive learning resources; students' use of textbooks has correspondingly declined. We designed an interactive iBook© for pre-clinical students encompassing the content of the pulmonary segment in an organ-based multidisciplinary course. We found, via a survey-based study, that students preferred the iBook to other faculty-supplied materials (PowerPoints and PDFs), mainly due to its interactive images, animations, and study questions. Students' test performance did not change significantly after introducing the iBook. This study suggests that expanded use of interactive learning resources may enhance students' engagement with pre-clinical courses.

Exercise Capacity in Unilateral Diaphragm Paralysis: The Effect of Obesity.

PURPOSE: Healthy patients with unilateral diaphragm paralysis (UDP) are often asymptomatic; those with UDP and comorbidities that increase work of breathing are often dyspneic. We report the effect of obesity on exercise capacity in UDP patients. METHODS: All obese and nonobese patients with UDP undergoing cardiopulmonary exercise testing (CPET) during a 32-month period in the exercise laboratory of an academic hospital were compared to a retrospectively identified cohort of obese and nonobese controls without UDP, matched for key features. CPET used a modified Bruce treadmill protocol with breath-to-breath expired gas analysis. O2 uptake, minute ventilation, exercise time, and work rate were recorded at peak exercise. Static pulmonary functions were measured. Kruskal-Wallis, Wilcoxon rank sum, and Fisher's exact tests were used to compare continuous and categorical variables, respectively. Stratified linear regression was used to quantify the effect of UDP and obesity on CPET variables. RESULTS: Twenty-two UDP patients and 46 controls were studied. The BMI of obese and nonobese patients was 33.0±4.2 and 25.8±2.4 kg/m2, respectively. UDP subjects with obesity, compared to controls with neither condition, showed significantly reduced peak O2 uptake normalized to actual body weight (1.57±0.64 versus 2.01±0.88 L/min), shorter exercise time (5.7±2.0 versus 8.5±2.9 minutes), and lower peak ventilation. This was not observed in UDP alone or obesity alone. Peak work rate trended lower in the combined UDP-obesity group. CONCLUSION: Neither UDP nor obesity alone significantly reduced exercise capacity. Superimposed UDP and obesity interact to create a ventilatory limitation to exercise, with reduced peak-VO2, exercise time, and work rate.

Use of student feedback to drive quality improvement (QI) in a preclinical U.S. medical school course.

Medical educators are continually looking for ways to enhance integrated learning and help students see how the material taught in their various courses is inter-related. . At Stony Brook School of Medicine, we embarked on a school-wide new curriculum called the Learning focused, Experiential, Adaptive, Rigorous and Novel (LEARN) curriculum and developed several integrated courses that were not based in specific departments. As part of this process, the pre-clinical (Phase-1) curriculum was shortened to 17 months to accommodate an expanded set of clinical offerings. The new structure called for teachers from different departments to lead and conduct the integrated blocks of pre-clinical courses. In this paper, we describe our discouraging experience with the first iteration of an integrated course in Cardiology, Pulmonology and Renal organ systems (CPR), and its transformation into a highly successful second iteration. This involved a systematic course quality improvement (QI) process within the context of a larger school wide curricular reform. As a result, student overall satisfaction with the course increased from 22% (28 of 127 responders) to 83% (111 of 134 responders); the mean score on a standardized NBME content exam increased by 6.7%. We report the systematic process we used to collect data from students and faculty that helped facilitate quality improvement in a key course in Phase-1 of our LEARN curriculum.

Palliative and end-of-life educational practices in US pulmonary and critical care training programs.

PURPOSE: To describe educational features in palliative and end-of-life care (PEOLC) in pulmonary/critical care fellowships and identify the features associated with perceptions of trainee competence in PEOLC. METHODS: A survey of educational features in 102 training programs and the perceived skill and comfort level of trainees in 6 PEOLC domains: communication, symptom control, ethical/legal, community/institutional resources, specific syndromes, and ventilator withdrawal. We evaluated associations between perceived trainee competence/comfort in PEOLC and training program features, using regression analyses. RESULTS: Fifty-five percent of program directors (PDs) reported faculty with training in PEOLC; 30% had a written PEOLC curriculum. Neither feature was associated with trainee competence/comfort. Program directors and trainees rated bedside PEOLC teaching highly. Only 20% offered PEOLC rotations; most trainees judged these valuable. Most PDs and trainees reported that didactic teaching was insufficient in communication, although sufficient teaching of this was associated with perceived trainee competence in communication. Perceived trainee competence in managing institutional resources was rated poorly. Program directors reporting significant barriers to PEOLC education also judged trainees less competent in PEOLC. Time constraint was the greatest barrier. CONCLUSION: This survey of PEOLC education in US pulmonary/critical care fellowships identified associations between certain program features and perceived trainee skill in PEOLC. These results generate hypotheses for further study.

Impact of critical care medicine training programs' palliative care education and bedside tools on ICU use at the end of life.

BACKGROUND: Intensive care unit (ICU) use at the end of life is rising. Little research has focused on associations among critical care fellows' training, institutional support, and bedside tools with ICU use at the end of life. OBJECTIVE: We evaluated whether hospital and critical care medicine program interventions were associated with ICU use in the last 6 months of life for patients with chronic illness. METHODS: Our observational, retrospective study explored associations between results from a survey of critical care program directors and hospital-level Medicare data on ICU use in the last 6 months of life. Program directors evaluated quality of palliative care education in their critical care fellowships and reported on the number of bedside tools and the presence or absence of an inpatient palliative care consultation service. RESULTS: For the 89 hospitals and 71 affiliated training programs analyzed, there were statistically significant relationships between 2 of the explanatory variables-the quality of palliative care education and the number of bedside tools-in ICU use. Each level of increased educational quality (1-5 Likert scale) was associated with a 0.57-day decrease in ICU days, whereas, for each additional, evidence-based bedside tool, there was a 0.31-day decrease. The presence of an inpatient palliative care program was not a significant predictor of ICU use. CONCLUSIONS: We found that the quality of palliative care training in critical care medicine programs and the use of bedside tools were independently associated with reduced ICU use at the end of life.

Sedation during mechanical ventilation: a trial of benzodiazepine and opiate in combination.

OBJECTIVE: To compare the efficacy of continuous intravenous sedation with midazolam alone vs. midazolam plus fentanyl ("co-sedation") during mechanical ventilation. DESIGN: A randomized, prospective, controlled trial. SETTING: A ten-bed medical intensive care unit at a university hospital. PATIENTS: Thirty patients with respiratory failure who were expected to require >48 hrs of mechanical ventilation and who were receiving a sedative regimen that did not include opiate pain control. INTERVENTIONS: An intravenous infusion of either midazolam alone or co-sedation was administered by a nurse-implemented protocol to achieve a target Ramsay Sedation Score set by the patient's physician. Study duration was 3 days, with a brief daily "wake-up." MEASUREMENTS AND MAIN RESULTS: We recorded the number of hours/day that patients were "off-target" with their Ramsay Sedation Scores, the number of dose titrations per day, the incidence of patient-ventilator asynchrony, and the time required to achieve adequate sedation as measures of sedative efficacy. We also recorded sedative cost in U.S. dollars and adverse events including hypotension, hypoventilation, ileus, and coma. Compared with the midazolam-only group, the co-sedation group had fewer hours per day with an "off-target" Ramsay Score (4.2 +/- 2.4 and 9.1 +/- 4.9, respectively, p < .002). Fewer episodes per day of patient-ventilator asynchrony were noted in the co-sedation group compared with midazolam-only (0.4 +/- 0.1 and 1.0 +/- 0.2, respectively, p < .05). Co-sedation also showed nonsignificant trends toward a shorter time to achieve sedation, a need for fewer dose titrations per day, and a lower total sedative drug cost. There was a trend toward more episodes of ileus with co-sedation compared with midazolam-only (2 vs. 0). CONCLUSIONS: In mechanically ventilated patients, co-sedation with midazolam and fentanyl by constant infusion provides more reliable sedation and is easier to titrate than midazolam alone, without significant difference in the rate of adverse events.

Impact of rapid on-site cytologic evaluation during transbronchial needle aspiration.

STUDY OBJECTIVE: To determine the extent to which rapid on-site cytologic evaluation (ROSE) of transbronchial needle aspiration (TBNA) samples can safely and cost-effectively reduce the need for additional biopsy during bronchoscopy. SETTING: University Hospital in Long Island, NY. PATIENT AND METHODS: Forty-four bronchoscopies with TBNA, most of which utilized ROSE, were evaluated prospectively. The number and types of biopsies performed during each procedure were compared to a preprocedural algorithm to determine the impact of knowing ROSE results during the procedure. Bronchoscopies performed with and without ROSE were compared, as were bronchoscopies with diagnostic and nondiagnostic ROSE results. A cost analysis was performed comparing the Medicare reimbursement for ROSE to the savings of deferring multiple biopsies. RESULTS: Thirty-two bronchoscopies were performed with ROSE; 12 were performed without ROSE. Fewer biopsies were performed during bronchoscopies utilizing ROSE. Diagnostic yield, TBNA sensitivity and accuracy, and procedural time were similar between these two groups. CONCLUSIONS: ROSE during TBNA allows for deferring additional biopsy without loss in diagnostic yield, likely lowers procedural risk, and is cost-effective.