Application of Machine Learning Models to Biomedical and Information System Signals From Critically Ill Adults

BACKGROUND

Machine learning (ML)-derived notifications for impending episodes of hemodynamic instability and respiratory failure events are interesting because they can alert physicians in time to intervene before these complications occur.

RESEARCH QUESTION

Do ML alerts, telemedicine system (TS)-generated alerts, or biomedical monitors (BMs) have superior performance for predicting episodes of intubation or administration of vasopressors?

STUDY DESIGN AND METHODS

An ML algorithm was trained to predict intubation and vasopressor initiation events among critically ill adults. Its performance was compared with BM alarms and TS alerts.

RESULTS

ML notifications were substantially more accurate and precise, with 50-fold lower alarm burden than TS alerts for predicting vasopressor initiation and intubation events. ML notifications of internal validation cohorts demonstrated similar performance for independent academic medical center external validation and COVID-19 cohorts. Characteristics were also measured for a control group of recent patients that validated event detection methods and compared TS alert and BM alarm performance. The TS test characteristics were substantially better, with 10-fold less alarm burden than BM alarms. The accuracy of ML alerts (0.87-0.94) was in the range of other clinically actionable tests; the accuracy of TS (0.28-0.53) and BM (0.019-0.028) alerts were not. Overall test performance (F scores) for ML notifications were more than fivefold higher than for TS alerts, which were higher than those of BM alarms.

INTERPRETATION

ML-derived notifications for clinically actioned hemodynamic instability and respiratory failure events represent an advance because the magnitude of the differences of accuracy, precision, misclassification rate, and pre-event lead time is large enough to allow more proactive care and has markedly lower frequency and interruption of bedside physician work flows.

Sampling of healthcare professionals' perspective on point-of-care technologies from 2019-2021: A survey of benefits, concerns, and development

Point-of-care technology (POCT) plays a vital role in modern healthcare by providing a fast diagnosis, improving patient management, and extending healthcare access to remote and resource-limited areas. The objective of this study was to understand how healthcare professionals in the United States perceived POCTs during 2019-2021 to assess the decision-making process of implementing these newer technologies into everyday practice. A 5-point Likert scale survey was sent to respondents to evaluate their perceptions of benefits, concerns, characteristics, and development of point-of-care technologies. The 2021 survey was distributed November 1st, 2021- February 15th, 2022, with a total of 168 independent survey responses received. Of the respondents, 59% identified as male, 73% were white, and 48% have been in practice for over 20 years. The results showed that most agreed that POCTs improve patient management (94%) and improve clinician confidence in decision making (92%). Healthcare professionals were most concerned with potentially not being reimbursed for the cost of the POCT (37%). When asked to rank the top 3 important characteristics of POCT, respondents chose accuracy, ease of use, and availability. It is important to note this survey was conducted during the COVID-19 pandemic. To achieve an even greater representation of healthcare professionals' point of view on POCTs, further work to obtain responses from a larger, more diverse population of providers is needed.

2021 Patient Preferences for Point of Care Testing Survey: More Acceptance and Less Concern

BACKGROUND

The evolving opinions of our community members provide insights into how end-users perceive the value and identify key point-of-care test (POCT) characteristics.

METHODS

We deployed our validated 45-item English-language survey to uncompensated volunteers and compared the results from 1264 respondents in 2021 with those obtained in 2020.

RESULTS

Average responses for items regarding the benefits of POCTs demonstrated that the 2021 respondents indicated agreement with all 14 potential benefits. Average responses for items regarding concerns were distinctly different from those for benefits. The only concern item that scored in the agree range was "not having insurance coverage for POCTs." Average responses to the other 13 concern items were in the disagree range. For 8 of these items, the magnitude of disagreement was greater in the 2021 survey than was observed for the 2020 survey. Differences in POCT exposure over time and by US regions suggest that higher levels of exposure to POCTs in the East are associated with stronger public support.

CONCLUSIONS

Community members strongly support the development of accurate, convenient, easy-to-use, affordable, equitably available, in-home POCTs that produce immediate results. This empowers patients and home caregivers to diagnose, manage, enhance their adherence to medical treatments, and more efficiently engage their physicians.

COVID-19: a gray swan's impact on the adoption of novel medical technologies

The COVID-19 pandemic offers a unique context and opportunity to investigate changes in healthcare professional perceptions towards the adoption of novel medical technologies, such as point-of-care technologies (POCTs). POCTs are a nascent technology that has experienced rapid growth as a result of COVID-19 due to their ability to increase healthcare accessibility via near-patient delivery, including at-home. We surveyed healthcare professionals before and during COVID-19 to explore whether the pandemic altered their perceptions about the usefulness of POCTs. Our network analysis method provided a structure for understanding this changing phenomenon. We uncovered that POCTs are not only useful for diagnosing COVID-19, but healthcare professionals also perceive them as increasingly important for diagnosing other diseases, such as cardiovascular, endocrine, respiratory, and metabolic diseases. Healthcare professionals also viewed POCTs as facilitating the humanization of epidemiology by improving disease management/monitoring and strengthening the clinician-patient relationship. As the accuracy and integration of these technologies into mainstream healthcare delivery improves, hurdles to their adoption dissipate, thereby encouraging healthcare professionals to rely upon them more frequently to diagnose, manage, and monitor diseases. The technological advances made in POCTs during COVID-19, combined with shifting positive perceptions of their utility by healthcare professionals, may better prepare us for the next pandemic.

Point-of-care testing, your cardiologist, and affairs of the heart

Background

Point-of-care testing (POCT) has applications across medical specialties and holds promise to improve patient care. While cardiovascular medicine has been attractive for POCT applications in recent years, little is known about how cardiovascular health professionals perceive them.

Objective

The objective of our study was to examine differences in perceptions and attitudes towards POCTs between cardiovascular health professionals compared to other healthcare professionals.

Methods

We surveyed healthcare professionals to assess perceptions of POCT usage and their benefits and concerns between October 2019 and March 2020. Questions regarding POCT perceptions were assessed on a 5-point Likert scale.

Results

We received a total of 148 survey responses; of the responders, 52% were male, 59% were physicians, and 50% worked in a hospital setting. We found that cardiology professionals were less likely, compared to other specialties, to view POCTs as improving patient management or reducing errors. These cardiology professionals were not constrained by resources or a lack of investment opportunities to implement these technologies.

Conclusion

This study provides a better understanding of perceptions about POCTs among healthcare specialists. To improve patient outcomes through the adoption and usage of POCTs, greater collaboration is advised among key industry and healthcare stakeholders.

Validation of an Automatic Tagging System for Identifying Respiratory and Hemodynamic Deterioration Events in the Intensive Care Unit

Objectives

Predictive models for critical events in the intensive care unit (ICU) might help providers anticipate patient deterioration. At the heart of predictive model development lies the ability to accurately label significant events, thereby facilitating the use of machine learning and similar strategies. We conducted this study to establish the validity of an automated system for tagging respiratory and hemodynamic deterioration by comparing automatic tags to tagging by expert reviewers.

Methods

This retrospective cohort study included 72,650 unique patient stays collected from Electronic Medical Records of the University of Massachusetts’ eICU. An enriched subgroup of stays was manually tagged by expert reviewers. The tags generated by the reviewers were compared to those generated by an automated system.

Results

The automated system was able to rapidly and efficiently tag the complete database utilizing available clinical data. The overall agreement rate between the automated system and the clinicians for respiratory and hemodynamic deterioration tags was 89.4% and 87.1%, respectively. The automatic system did not add substantial variability beyond that seen among the reviewers.

Conclusions

We demonstrated that a simple rule-based tagging system could provide a rapid and accurate tool for mass tagging of a compound database. These types of tagging systems may replace human reviewers and save considerable resources when trying to create a validated, labeled database used to train artificial intelligence algorithms. The ability to harness the power of artificial intelligence depends on efficient clinical validation of targeted conditions; hence, these systems and the methodology used to validate them are crucial.

Vaping-Associated Respiratory Distress Syndrome: Case Classification and Clinical Guidance

Exposure to vaping is associated with a growing list of respiratory syndromes including an acute progressive form with life-threatening hypoxemic respiratory failure and pathologic changes of lung injury termed vaping-associated respiratory distress syndrome.

DATA SOURCES

Center from Disease Control, Departments of Public Health, MEDLINE (via PubMed), and the Cochrane Library.

STUDY SELECTION DATA EXTRACTION AND DATA SYNTHESIS

Cases, series, and public health reports of cases that met the Centers for Disease Control and Prevention case definition of vaping-associated respiratory disease were extracted by an author with perfect verification by a second. Cases were classified on the basis of toxin exposure, symptoms, oxygen saturation, progression to respiratory failure, and pathologic features, and a clinically actionable system of classification was based on expert opinion.

CONCLUSIONS

The reported spectrum of vaping-associated respiratory diseases allows clinical classification of cases into groups with distinct evaluation, management, and recommendations for prevention and follow-up. Clinical stratification also identifies a small proportion of vaping-exposed patients who are at risk for progression to hypoxemic respiratory failure and an acute respiratory distress syndrome-like illness.

Evolution of the Intensive Care Unit Telemedicine Value Proposition

Advances in clinical information sciences, telecommunication technologies, electronic health records, early warning systems, automated acuity assessment, and clinician communication support systems have allowed current-generation intensive care (ICU) telemedicine systems to address the inefficiencies of the failed advice-upon-request ICU telemedicine model. Value is related to the ability of health care systems to leverage ICU telemedicine resources to provide care. Local financial benefits of ICU telemedicine program implementation depend on changing behavior to better focus on activities that reduce the duration of critical illness and length of stay.

Comparative Effectiveness of Proton Pump Inhibitors vs Histamine Type 2 Receptor Blockers for Preventing Clinically Important Gastrointestinal Bleeding During Intensive Care: A Population-Based Study

BACKGROUND

Proton pump inhibitors (PPIs) and histamine type 2 receptor blockers (H2Bs) are used for stress ulcer prophylaxis. Although the PPIs have greater potency for acid suppression, their relative effectiveness for preventing clinically important GI bleeding (CIGIB) has not been established. The goal of this study was to determine whether prophylactic PPIs were associated with lower risk of CIGIB than H2Bs among critically ill adults.

METHODS

This retrospective cohort study included adults with critical illness from January 1, 2008, to June 30, 2012, who had at least one stress ulcer risk factor and received a PPI or H2B for ≥ 3 days. Cox proportional hazards regression propensity score matching and instrumental variable analyses were used to control for selection bias and confounding by unmeasured factors. The Acute Physiology and Chronic Health Evaluation Score version IV score was used to adjust for differences of acuity. The main outcome and exposure was CIGIB.

RESULTS

Among 70,093 patients at risk, 49,576 (70.7%) received prophylaxis for at least 3 days, and 424 patients (0.6%) met the definition for experiencing CIGIB. The hazard for CIGIB was two times greater for PPI users compared with H2B users (adjusted hazard ratio, 1.82 [95% CI, 1.19-2.78]; hazard ratio, 2.37 [95% CI, 1.61-3.5]). Sensitivity analyses failed to detect any plausible scenario in which PPIs were superior to H2Bs for the prevention of CIGIB.

CONCLUSIONS

H2Bs were robustly and consistently associated with significantly lower CIGIB risk compared with PPIs in this population.

Red Blood Cell Product Transfusion Thresholds and Clinical Outcomes

OBJECTIVE

To determine whether patients transfused red blood cell (RBC) products according to guideline-specified pretransfusion hemoglobin (Hb) concentrations or for other reasons were more likely to survive their intensive care unit (ICU) stay.

DESIGN

An observational study of 375 478 episodes of ICU care, over 5 years, was performed with ICU survival as the primary outcome. Outcomes were analyzed as a function of pretransfusion Hb concentration for groups with distinct transfusion indications while adjusting for potential confounders.

SETTING AND PATIENTS

This study included all adult patients discharged from 1 of 203 adult ICUs from 32 US health-care systems. The patients were from community hospitals, tertiary, and academic medical centers.

INTERVENTION

Transfusion of allogenic packed RBCs or whole blood was prescribed at the discretion of the treating clinicians.

MEASUREMENTS AND MAIN RESULTS

We found that 15% of adult ICU patients are transfused RBC products, and most transfusions for hemodynamically stable patients are administered above the guideline-specified pretransfusion Hb threshold of 7 g/dL. Hemodynamically stable patients transfused below this threshold were significantly more likely to survive their ICU stay than those not transfused (odds ratio [OR] 0.59, 95% confidence interval [CI], 0.43-0.81; P = .001), and patients transfused at thresholds above 9 g/dL were less likely to survive their ICU stay than those not transfused. Patients of the acute blood loss group who were transfused appeared to benefit or were not harmed by transfusion.

CONCLUSION

Conservative RBC product transfusion practices for groups that are targeted by guidelines are justified by outcomes observed in clinical practice. This study provides evidence for the liberal administration of RBC products to critically ill adults with acute blood loss based on association with lower risk of mortality.

The effect of montelukast on early-life wheezing: A randomized, double-blinded placebo-controlled study

BACKGROUND

Cysteinyl-leukotrienes are increased in the airways of infants with virus-associated wheezing. We aimed to determine the effects of a cysteinyl-leukotriene-1 receptor antagonist on symptoms during an early-life wheezing illness and to investigate the factors that affect the response to this drug.

METHOD

This placebo-controlled double-blinded randomized controlled trial recruited children aged 3-36 months with wheezing illness and randomized to active drug or placebo for 56 days. A symptom score diary (SSD) was kept by the children's caregivers.

RESULTS

One-hundred patients completed the study, and 62 (30 montelukast and 32 placebo) were analyzed. There were no significant differences in the percent of symptom-free days, symptom scores, and the need for rescue salbutamol between the two groups. However, the percent of symptom-free days within the first week was significantly higher for the montelukast than for the placebo group (13.8 ± 4.1% vs. 5.4 ± 3.4%; P = 0.028); wheezing score at 7th day was significantly lower for the montelukast than for the placebo group (0.5 ± 0.1 vs. 1.4 ± 0.2; P = 0.002). In addition, the number of inhaled ß₂ -agonist rescue episodes per day during the first week was significantly lower for the montelukast compared with the placebo group (12.7 ± 1.8 vs. 19.2 ± 1.6; P = 0.013). Conclusions Our results indicate that montelukast may be effective for reducing caregiver-observed wheezing and the need for salbutamol during the first week of treatment for early-life wheezing. The impact for caregivers and the optimal duration of treatment will need to be explored in studies of larger size.

Five-Year Trends of Critical Care Practice and Outcomes

BACKGROUND

Longitudinal analyses of large, detailed adult critical care datasets provide insights into practice trends and generate useful outcome and process benchmarks.

METHODS

Data representing 991,571 consecutive critical care visits to 160 US adult ICUs from 2009 to 2013 from the eICU Research Institute clinical practice database were used to quantitate patient characteristics, APACHE IV-based acuity predictions, treatments, and outcomes. Analyses for changes over time were performed for patient characteristics, entry and discharge locations, primary admission diagnosis, treatments, adherence to consensus ICU best practices, length of stay (LOS), and inpatient mortality.

RESULTS

We detected significant trends for increasing age, BMI, and risk of mortality, higher frequency of admission from an ED and stepdown unit, and more frequent hospital discharge to substance abuse centers and skilled nursing facilities. Significantly more patients were admitted for sepsis, emphysema, coma, congestive heart failure, diabetic ketoacidosis, and fewer were admitted for asthma, unspecified chest pain, coronary artery bypass graft, and stroke care. The frequency of noninvasive mechanical ventilation and adherence to critical care best practices significantly increased, whereas the duration of renal replacement therapies, frequency of transfusions, antimicrobial use, critical care complications, LOS, and inpatient mortality decreased.

CONCLUSIONS

Analyses of patients, practices, and outcomes from a large geographically dispersed sample of adult ICUs revealed trends of increasing age and acuity, higher rates of adherence to best practice, use of noninvasive mechanical ventilation, and decreased use of antimicrobials, transfusions, and duration of renal replacement therapies. Acuity-adjusted LOS and in hospital mortality decreased.

A 10-Year Review of Total Hospital-Onset ICU Bloodstream Infections at an Academic Medical Center

BACKGROUND

The rates of central line-associated bloodstream infections (CLABSIs) in U.S. ICUs have decreased significantly, and a parallel reduction in the rates of total hospital-onset bacteremias in these units should also be expected. We report 10-year trends for total hospital-onset ICU-associated bacteremias at a tertiary-care academic medical center.

METHODS

This was a retrospective analysis of all positive-result blood cultures among patients admitted to seven adult ICUs for fiscal year 2005 (FY2005) through FY2014 according to Centers for Disease Control and Prevention National Healthcare Safety Network definitions. The rate of change for primary and secondary hospital-onset BSIs was determined, as was the distribution of organisms responsible for these BSIs. Data from three medical, two general surgical, one combined neurosurgical/trauma, and one cardiac/cardiac surgery adult ICU were analyzed.

RESULTS

Across all ICUs, the rates of primary BSIs progressively fell from 2.11/1,000 patient days in FY2005 to 0.32/1,000 patient days in FY2014; an 85.0% decrease (P < .0001). Secondary BSIs also progressively decreased from 3.56/1,000 to 0.66/1,000 patient days; an 81.4% decrease (P < .0001). The decrease in BSI rates remained significant after controlling for the number of blood cultures obtained and patient acuity.

CONCLUSIONS

An increased focus on reducing hospital-onset infections at the academic medical center since 2005, including multimodal multidisciplinary efforts to prevent central line-associated BSIs, pneumonia, Clostridium difficile disease, surgical site infections, and urinary tract infections, was associated with progressive and sustained decreases for both primary and secondary hospital-onset BSIs.

ICU Telemedicine Program Financial Outcomes

BACKGROUND

ICU telemedicine improves access to high-quality critical care, has substantial costs, and can change financial outcomes. Detailed information about financial outcomes and their trends over time following ICU telemedicine implementation and after the addition of logistic center function has not been published to our knowledge.

METHODS

Primary data were collected for consecutive adult patients of a single academic medical center. We compared clinical and financial outcomes across three groups that differed regarding telemedicine support: a group without ICU telemedicine support (pre-ICU intervention group), a group with ICU telemedicine support (ICU telemedicine group), and an ICU telemedicine group with added logistic center functions and support for quality-care standardization (logistic center group). The primary outcome was annual direct contribution margin defined as aggregated annual case revenue minus annual case direct costs (including operating costs of ICU telemedicine and its related programs). All monetary values were adjusted to 2015 US dollars using Producer Price Index for Health-Care Facilities.

RESULTS

Annual case volume increased from 4,752 (pre-ICU telemedicine) to 5,735 (ICU telemedicine) and 6,581 (logistic center). The annual direct contribution margin improved from $7,921,584 (pre-ICU telemedicine) to $37,668,512 (ICU telemedicine) to $60,586,397 (logistic center) due to increased case volume, higher case revenue relative to direct costs, and shorter length of stay.

CONCLUSIONS

The ability of properly modified ICU telemedicine programs to increase case volume and access to high-quality critical care with improved annual direct contribution margins suggests that there is a financial argument to encourage the wider adoption of ICU telemedicine.

Systemic Capillary Leak Syndrome, Leukotrienes, and Anaphylaxis

The association of cysteinyl leukotrienes with plasma exudation allowed the authors to form the hypothesis that rates of leukotriene excretion would be increased in the acute phase of systemic capillary leak syndrome (SCLS) and that leukotriene-modifier therapy would reduce the frequency and severity of life-threatening episodes. The authors report the association of SCLS in 3 cases, 1 with seafood-induced anaphylaxis. Rates of urinary leukotriene excretion were greater during the evolution of an episode than after resolution. In a third case, the rate of urinary leukotriene excretion was significantly higher when symptoms were evolving than when they were absent (230 ± 17 vs 110 ± 6 pg/mg, P < 0.001). Treatment with a leukotriene receptor (cys-LT1) antagonist eliminated episodes in 1 patient. Treatment with the 5-lipoxygenase inhibitor zileuton was completely effective in another patient and prevented life-threatening episodes in the patient with SCLS after seafood exposure. The authors' finding that allergen exposure—associated episodes of SCLS were eliminated by allergen avoidance implies that anaphylaxis can present as SCLS. The acute phase of all 3 forms of SCLS (paraprotein associated, anaphylaxis associated, and idiopathic) is associated with increased excretion of cystinyl leukotrienes, and leukotriene-modifier treatment appears to control the disease.

Intensivist Staffing: Evolving Challenges and Solutions

Increases in critical care utilization related to aging of our population, static supplies of critical care specialists, and reduced availability of physicians in training to staff intensive care units (ICUs) have led many institutions to reevaluate their ICU prescribing provider staffing plans. The epidemiology of critical care staffing needs, regulations, requirements, standards, and professional society staffing recommendations are reviewed and the components of a prescribing provider staffing plan are described along with their costs. Factors that impact staffing costs including the availability of intensivist extenders, electronic support, and telemedicine tools that impact the efficiency of care delivery are evaluated in the context of staffing plan evaluation. Financial modeling is used to compare the costs of common prescribing provider staffing plans for typical referral medical center ICUs, community hospital ICUs, and rural health centers that care for the critically ill.

Standardizing communication from acute care providers to primary care providers on critically ill adults

OBJECTIVE

To increase the frequency of communication of patient information between acute and primary care providers. A secondary objective was to determine whether higher rates of communication were associated with lower rates of hospital readmission 30 days after discharge.

METHODS

A validated instrument was used for telephone surveys before and after an intervention designed to increase the frequency of communication among acute care and primary care providers. The communication intervention was implemented in 3 adult intensive care units from 2 campuses of an academic medical center.

RESULTS

The frequency of communication among acute care and primary care providers, the perceived usefulness of the intervention, and its association with 30-day readmission rates were assessed for 202 adult intensive care episodes before and 100 episodes after a communication intervention. The frequency of documented communication increased significantly (5/202 or 2% before to 72/100 or 72% after the intervention; P < .001) and the communication was considered useful by every participating primary care provider. Rates of rehospitalization at 30 days were lower for the intervention group than the preintervention group, but the difference was not statistically significant (41/202 or 23% vs 16/88 or 18% of discharged patients; P = .45; power 0.112 at P = .05).

CONCLUSIONS

The frequency of communication episodes that provide value can be increased through standardized processes. The key aspects of this effective intervention were setting the expectation that communication should occur, documenting when communication has occurred, and reviewing that documentation during multiprofessional rounds.

ICU Telemedicine Solutions

During the last 15 years, critical care services provided via telemedicine have expanded to now be incorporated into the care of 13% of patients in intensive care units (ICUs) in the United States. A response to shortfalls in the availability of critical care-trained providers has evolved into integrated programs of ICU care with contributions to improved outcomes through proactive management, population oversight, and standardization of care processes. The most impactful characteristics of successful ICU telemedicine programs are now better understood with more than a decade of national experience and the accrued benefits to health care systems.

Thrombosis prophylaxis and mortality risk among critically ill adults

BACKGROUND

The optimal approach for managing increased risk of VTE among critically ill adults is unknown.

METHODS

An observational study of 294,896 episodes of critical illness among adults was conducted in 271 geographically dispersed US adult ICUs. The primary outcomes were all-cause ICU and in-hospital mortality after adjustment for acuity and other factors among groups of patients assigned, based on clinical judgment, to prophylactic anticoagulation, mechanical devices, both, or neither. Outcomes of those managed with prophylactic anticoagulation or mechanical devices were compared in a separate paired, propensity-matched cohort.

RESULTS

After adjustment for propensity to receive VTE prophylaxis, APACHE (Acute Physiology and Chronic Health Evaluation) IV scores, and management with mechanical ventilation, the group treated with prophylactic anticoagulation was the only one with significantly lower risk of dying than those not provided VTE prophylaxis (ICU, 0.81 [95% CI, 0.79-0.84]; hospital, 0.84 [95% CI, 0.82-0.86; P < .0001). The mortality risk of those receiving mechanical device prophylaxis was not lower than that of patients without VTE prophylaxis. A study of 87,107 pairs of patients matched for propensity to receive VTE prophylaxis found that those managed with prophylactic anticoagulation therapy had significantly lower risk of death (ICU subhazard ratio, 0.82 [95% CI, 0.78-0.85]; hospital subhazard ratio, 0.82 [95% CI, 0.79-0.85]; P < .001) than those receiving only mechanical device prophylaxis.

CONCLUSIONS

These findings support a recommendation for prophylactic anticoagulation therapy in preference to mechanical device prophylaxis for critically ill adult patients who do not have a contraindication to anticoagulation.

A multicenter study of ICU telemedicine reengineering of adult critical care

BACKGROUND

Few studies have evaluated both the overall effect of ICU telemedicine programs and the effect of individual components of the intervention on clinical outcomes.

METHODS

The effects of nonrandomized ICU telemedicine interventions on crude and adjusted mortality and length of stay (LOS) were measured. Additionally, individual intervention components related to process and setting of care were evaluated for their association with mortality and LOS.

RESULTS

Overall, 118,990 adult patients (11,558 control subjects, 107,432 intervention group patients) from 56 ICUs in 32 hospitals from 19 US health-care systems were included. After statistical adjustment, hospital (hazard ratio [HR]=0.84; 95% CI, 0.78-0.89; P<.001) and ICU (HR=0.74; 95% CI, 0.68-0.79; P<.001) mortality in the ICU telemedicine intervention group was significantly better than that of control subjects. Moreover, adjusted hospital LOS was reduced, on average, by 0.5 (95% CI, 0.4-0.5), 1.0 (95% CI, 0.7-1.3), and 3.6 (95% CI, 2.3-4.8) days, and adjusted ICU LOS was reduced by 1.1 (95% CI, 0.8-1.4), 2.5 (95% CI, 1.6-3.4), and 4.5 (95% CI, 1.5-7.2) days among those who stayed in the ICU for ≥7, ≥14, and ≥30 days, respectively. Individual components of the interventions that were associated with lower mortality, reduced LOS, or both included (1) intensivist case review within 1 h of admission, (2) timely use of performance data, (3) adherence to ICU best practices, and (4) quicker alert response times.

CONCLUSIONS

ICU telemedicine interventions, specifically interventions that increase early intensivist case involvement, improve adherence to ICU best practices, reduce response times to alarms, and encourage the use of performance data, were associated with lower mortality and LOS.

Prehospital management of evolving critical illness by the primary care provider

BACKGROUND

The factors that limit primary care providers (PCPs) from intervening for adults with evolving, acute, severe illness are less understood than the increasing frequency of management by acute care providers.

METHODS

Rates of prehospital patient management by a PCP and of communication with acute care teams were measured in a multicenter, cross-sectional, descriptive study conducted in all four of the adult medical ICUs of the three hospitals in central Massachusetts that provide tertiary care. Rates were measured for 390 critical care encounters, using a validated instrument to abstract the medical record and conduct telephone interviews.

RESULTS

PCPs implemented prehospital management for eight episodes of acute illness among 300 encounters. Infrequent prehospital management by PCPs was attributed to their lack of awareness of the patient's evolving acute illness. Only 21% of PCPs were aware of the acute illness before their patient was admitted to an ICU, and 33% were not aware that their patient was in an ICU. Rates of PCP involvement were not appreciably different among provider groups or by patient age, sex, insurance status, hospital, ICU, or ICU staffing model.

CONCLUSIONS

We identified lack of PCP awareness of patients' acute illness and high rates of PCP referral to acute care providers as the most frequent barriers to prehospital management of evolving acute illness. These findings suggest that implementing processes that encourage early patient-PCP communication and increase rates of prehospital management of infections and acute exacerbations of chronic diseases could reduce use of acute care services.

Interdisciplinary collaboration: the slogan that must be achieved for models of delivering critical care to be successful

There is wide acceptance of the concept that interdisciplinary collaboration is an essential building block for successful health-care teams. This belief is grounded in our understanding of how teams function to address complex care needs that change with acute illness or injury. This general agreement has been validated in studies that have reported favorable outcomes associated with successfully implementing interdisciplinary models of health-care delivery in non-critical care settings. The very short time frames over which the care needs of critically ill or injured adults change and the team approach taken by nearly all ICUs strongly suggest that interdisciplinary collaboration is also beneficial in this setting. In this commentary, we define interdisciplinary collaboration and share the story of how we successfully redesigned and transformed our system-wide, interdisciplinary collaborative model for delivering critical care in order to share the lessons we learned as the process evolved with those who are about to embark on a similar challenge. We anticipate that those health-care systems that successfully implement interdisciplinary collaboration will be ahead of the curve in providing high-quality care at as low a cost as possible. Such institutions will also potentially be better positioned for improving teaching and providing a better foundation for critical care research in their institutions.

Evaluation of intravenous voriconazole in patients with compromised renal function

Background

Incorporation of the solubilizing excipient, sulfobutylether-β-cyclodextrin (SBECD), in the intravenous (IV) formulation of voriconazole has resulted in the recommendation that this formulation be used with caution in patients with creatinine clearances (Cl_cr) < 50 mL/min. This study evaluated the safety of IV voriconazole compared with two other IV antifungals not containing SBECD in patients with compromised renal function.

Methods

A total of 128 patients aged 11–93 years who had a baseline Cl_cr < 50 mL/min between January 1, 2007 and December 31, 2010 were identified from a database of a university-affiliated inpatient healthcare system; of these, 55 patients received caspofungin, 54 patients received fluconazole, and 19 patients received voriconazole. Changes in serum creatinine (S_cr) and Cl_cr levels while on therapy were compared with baseline values and between groups.

Results

The groups had similar characteristics apart from the larger proportion of females that received fluconazole. Baseline S_cr was higher in those receiving caspofungin, but maximal increases of S_cr and decreases in Cl_cr were greatest for the fluconazole group. Acute kidney injury (AKI), assessed by RIFLE criteria, was more frequent in the fluconazole vs. the caspofungin group (p < 0.01); incidence of AKI in the voriconazole group was not significantly different than found in the other two groups. The infecting organism was a predictor of AKI and formulation with SBECD was not.

Conclusions

Treatment of fungal infections in patients with compromised renal function with an SBECD-containing antifungal agent was not associated with AKI in clinical practice. Since the infecting organism was associated with AKI, decision on which antifungal to use should be determined by susceptibilities to the organism and not the incorporation of SBECD in the IV formulation.

The research agenda in ICU telemedicine: a statement from the Critical Care Societies Collaborative

ICU telemedicine uses audiovisual conferencing technology to provide critical care from a remote location. Research is needed to best define the optimal use of ICU telemedicine, but efforts are hindered by methodological challenges and the lack of an organized delivery approach. We convened an interdisciplinary working group to develop a research agenda in ICU telemedicine, addressing both methodological and knowledge gaps in the field. To best inform clinical decision-making and health policy, future research should be organized around a conceptual framework that enables consistent descriptions of both the study setting and the telemedicine intervention. The framework should include standardized methods for assessing the preimplementation ICU environment and describing the telemedicine program. This framework will facilitate comparisons across studies and improve generalizability by permitting context-specific interpretation. Research based on this framework should consider the multidisciplinary nature of ICU care and describe the specific program goals. Key topic areas to be addressed include the effect of ICU telemedicine on the structure, process, and outcome of critical care delivery. Ideally, future research should attempt to address causation instead of simply associations and elucidate the mechanism of action in order to determine exactly how ICU telemedicine achieves its effects. ICU telemedicine has significant potential to improve critical care delivery, but high-quality research is needed to best inform its use. We propose an agenda to advance the science of ICU telemedicine and generate research with the greatest potential to improve patient care.

Induction of mucin and MUC5AC expression by the protease activity of Aspergillus fumigatus in airway epithelial cells

Allergic bronchopulmonary mycosis, characterized by excessive mucus secretion, airflow limitation, bronchiectasis, and peripheral blood eosinophilia, is predominantly caused by a fungal pathogen, Aspergillus fumigatus. Using DNA microarray analysis of NCI-H292 cells, a human bronchial epithelial cell line, stimulated with fungal extracts from A. fumigatus, Alternaria alternata, or Penicillium notatum, we identified a mucin-related MUC5AC as one of the genes, the expression of which was selectively induced by A. fumigatus. Quantitative RT-PCR, ELISA, and histochemical analyses confirmed an induction of mucin and MUC5AC expression by A. fumigatus extracts or the culture supernatant of live microorganisms in NCI-H292 cells and primary cultures of airway epithelial cells. The expression of MUC5AC induced by A. fumigatus extracts diminished in the presence of neutralizing Abs or of inhibitors of the epidermal growth factor receptor or its ligand, TGF-α. We also found that A. fumigatus extracts activated the TNF-α-converting enzyme (TACE), critical for the cleavage of membrane-bound pro-TGF-α, and its inhibition with low-molecular weight inhibitors or small interfering RNA suppressed the expression of MUC5AC. The protease activity of A. fumigatus extracts was greater than that of other fungal extracts, and treatment with a serine protease inhibitor, but not with a cysteine protease inhibitor, eliminated its ability to activate TACE or induce the expression of MUC5AC mRNA in NCI-H292. In conclusion, the prominent serine protease activity of A. fumigatus, which caused the overproduction of mucus by the bronchial epithelium via the activation of the TACE/TGF-α/epidermal growth factor receptor pathway, may be a pathogenetic mechanism of allergic bronchopulmonary mycosis.

Hospital mortality, length of stay, and preventable complications among critically ill patients before and after tele-ICU reengineering of critical care processes

CONTEXT

The association of an adult tele-intensive care unit (ICU) intervention with hospital mortality, length of stay, best practice adherence, and preventable complications for an academic medical center has not been reported.

OBJECTIVE

To quantify the association of a tele-ICU intervention with hospital mortality, length of stay, and complications that are preventable by adherence to best practices.

DESIGN, SETTING, AND PATIENTS

Prospective stepped-wedge clinical practice study of 6290 adults admitted to any of 7 ICUs (3 medical, 3 surgical, and 1 mixed cardiovascular) on 2 campuses of an 834-bed academic medical center that was performed from April 26, 2005, through September 30, 2007. Electronically supported and monitored processes for best practice adherence, care plan creation, and clinician response times to alarms were evaluated.

MAIN OUTCOME MEASURES

Case-mix and severity-adjusted hospital mortality. Other outcomes included hospital and ICU length of stay, best practice adherence, and complication rates.

RESULTS

The hospital mortality rate was 13.6% (95% confidence interval [CI], 11.9%-15.4%) during the preintervention period compared with 11.8% (95% CI, 10.9%-12.8%) during the tele-ICU intervention period (adjusted odds ratio [OR], 0.40 [95% CI, 0.31-0.52]). The tele-ICU intervention period compared with the preintervention period was associated with higher rates of best clinical practice adherence for the prevention of deep vein thrombosis (99% vs 85%, respectively; OR, 15.4 [95% CI, 11.3-21.1]) and prevention of stress ulcers (96% vs 83%, respectively; OR, 4.57 [95% CI, 3.91-5.77], best practice adherence for cardiovascular protection (99% vs 80%, respectively; OR, 30.7 [95% CI, 19.3-49.2]), prevention of ventilator-associated pneumonia (52% vs 33%, respectively; OR, 2.20 [95% CI, 1.79-2.70]), lower rates of preventable complications (1.6% vs 13%, respectively, for ventilator-associated pneumonia [OR, 0.15; 95% CI, 0.09-0.23] and 0.6% vs 1.0%, respectively, for catheter-related bloodstream infection [OR, 0.50; 95% CI, 0.27-0.93]), and shorter hospital length of stay (9.8 vs 13.3 days, respectively; hazard ratio for discharge, 1.44 [95% CI, 1.33-1.56]). The results for medical, surgical, and cardiovascular ICUs were similar.

CONCLUSION

In a single academic medical center study, implementation of a tele-ICU intervention was associated with reduced adjusted odds of mortality and reduced hospital length of stay, as well as with changes in best practice adherence and lower rates of preventable complications.

A microarray analysis of the effects of moderate hypothermia and rewarming on gene expression by human hepatocytes (HepG2)

The gene expression changes produced by moderate hypothermia are not fully known, but appear to differ in important ways from those produced by heat shock. We examined the gene expression changes produced by moderate hypothermia and tested the hypothesis that rewarming after hypothermia approximates a heat-shock response. Six sets of human HepG2 hepatocytes were subjected to moderate hypothermia (31 degrees C for 16 h), a conventional in vitro heat shock (43 degrees C for 30 min) or control conditions (37 degrees C), then harvested immediately or allowed to recover for 3 h at 37 degrees C. Expression analysis was performed with Affymetrix U133A gene chips, using analysis of variance-based techniques. Moderate hypothermia led to distinct time-dependent expression changes, as did heat shock. Hypothermia initially caused statistically significant, greater than or equal to twofold changes in expression (relative to controls) of 409 sequences (143 increased and 266 decreased), whereas heat shock affected 71 (35 increased and 36 decreased). After 3 h of recovery, 192 sequences (83 increased, 109 decreased) were affected by hypothermia and 231 (146 increased, 85 decreased) by heat shock. Expression of many heat shock proteins was decreased by hypothermia but significantly increased after rewarming. A comparison of sequences affected by thermal stress without regard to the magnitude of change revealed that the overlap between heat and cold stress was greater after 3 h of recovery than immediately following thermal stress. Thus, while some overlap occurs (particularly after rewarming), moderate hypothermia produces extensive, time-dependent gene expression changes in HepG2 cells that differ in important ways from those induced by heat shock.

Evaluation of the Impact of a tele-ICU Pharmacist on the Management of Sedation in Critically III Mechanically Ventilated Patients

Background:

An organized and uniform approach to managing sedation in critically ill patients has been associated with improved outcomes, but the most effective means of optimizing sedative medication use in clinical practice has not been fully determined. Pharmacist interventions directed at improving sedation guideline compliance have been shown to reduce the duration of mechanical ventilation.

Objective:

To determine the impact that pharmacy staffing configurations that include a tele-ICU pharmacist have on compliance with an intensive care unit (ICU) sedation guideline in critically ill mechanically ventilated patients requiring continuous-infusion sedative medications.

Methods:

Compliance with an established ICU sedation guideline, the performance of daily sedative interruptions, and the number of sedative medication–related interventions were evaluated before and after expansion of the ICU pharmacist staffing model to include comprehensive off-hours pharmacist coverage supported with established tele-ICU resources. In both groups, sedation was managed by the primary ICU team. In the intervention group, a pharmacist working in the tele-ICU center performed electronic record audits and made sedative medication recommendations to the primary team.

Results:

The addition of third shift tele-ICU pharmacist support was associated with a significant increase in the percentage of patients who received a daily sedative interruption (45% vs 54%; p < 0.0001). This occurred in the context of significant increases in the total number of ICU pharmacist interventions (36 vs 49.4 per 100 patient days, p < 0.0001), the number of therapeutic interventions (20.4 vs 26.1 per 100 patient days, p < 0.001), and the number of sedative-related interventions (0.9 vs 4.4 per 100 patient days, p < 0.0001).

Conclusions:

Tele-ICU resources can be utilized to increase compliance with an established ICU sedation guideline and extend the benefits that daytime ICU clinical pharmacy services provide. Increased ICU pharmacist availability may have additional benefits not measured in this study.

Glutathione prevents the early asthmatic reaction and airway hyperresponsiveness in guinea pigs

The prevalence of asthma has increased worldwide. The reasons for this rise remain unclear. Oxidative stress plays an important role in the pathogenesis of asthma. Glutathione (GSH) is the major representative of the class of nonprotein thiols and plays a pivotal role in a variety of enzymatic and nonenzymatic reactions that protect tissues against oxidative stress. In antioxidative reactions, GSH is converted into its oxidized form, glutathione disulfide (GSSG) that in its turn is enzymatically reduced into GSH to maintain a physiological redox balance. We used a guinea pig model of asthma to assess whether the early asthmatic reaction is associated with decreased lung levels of glutathione, and whether decreased glutathione is implicated in the increased airway smooth muscle reactivity that is associated with exposure of the lungs to allergen. Lung glutathione levels were decreased immediately after the onset of the early asthmatic reaction in vivo and associated with the release of 8-iso-PGF(2alpha), an indicator for oxidative stress. Glutathione ethylester, a glutathione precursor, blunted the airway obstruction during an early asthmatic reaction in a perfusion model and glutathione depletion rendered the airways hyperreactive. Glutathione ethyl ester in the buffer prevented this hyperreactivity. These results indicate that glutathione can modulate the early asthmatic reaction as well as the airway hyperresponsiveness.

Tele-ICU: experience to date

Tele-intensive care unit (ICU) is a care provided to critically ill patients by off-site clinicians using audio, video, and electronic links to leverage technical, informational, and clinical resources. Providing care includes the ability to detect patient's instability or laboratory abnormalities in real-time, collect additional clinical information from or about the patient, order diagnostic testing, make diagnoses, implement treatment, render other forms of intensive care such as managing life-support devices, and communicate with patients and bedside providers. This review summarizes how tele-ICU services are delivered, the alternative approaches that have been used, and summarizes published reports of its effects on patient-focused outcomes. Tele-ICU is thought to have great promise to support critically ill adults.

Ontogeny of the eotaxins in human lung

The ontogeny of the C-C chemokines eotaxin-1, eotaxin-2, and eotaxin-3 has not been fully elucidated in human lung. We explored a possible role for eotaxin in developing lung by determining the ontogeny of eotaxin-1 (CCL11), eotaxin-2 (CCL24), eotaxin-3 (CCL26), and the eotaxin receptor, CCR3. We tested discarded surgical samples of developing human lung tissue using quantitative RT-PCR (QRT-PCR) and immunostaining for expression of CCL11, CCL24, CCL26, and CCR3. We assessed possible functionality of the eotaxin-CCR3 system by treating lung explant cultures with exogenous CCL11 and analyzing the cultures for evidence of changes in proliferation and activation of ERK1/2, a signaling pathway associated with CCR3. QRT-PCR analyses of 22 developing lung tissue samples with gestational ages 10-23 wk demonstrated that eotaxin-1 mRNA is most abundant in developing lung, whereas mRNAs for eotaxin-2 and eotaxin-3 are minimally detectable. CCL11 mRNA levels correlated with gestational age (P < 0.05), and immunoreactivity was localized predominantly to airway epithelial cells. QRT-PCR analysis detected CCR3 expression in 16 of 19 developing lung samples. Supporting functional capacity in the immature lung, CCL11 treatment of lung explant cultures resulted in significantly increased (P < 0.05) cell proliferation and activation of the ERK signaling pathway, which is downstream from CCR3, suggesting that proliferation was due to activation of CCR3 receptors by CCL11. We conclude that developing lung expresses the eotaxins and functional CCR3 receptor. CCL11 may promote airway epithelial proliferation in the developing lung.

Multiple chemokine receptors, including CCR6 and CXCR3, regulate antigen-induced T cell homing to the human asthmatic airway

Human allergic asthma is a chronic inflammatory disease of the airways thought to be driven by allergen-specific Th2 cells, which are recruited into the lung in response to inhaled allergen. To identify chemoattractant receptors that control this homing pattern, we used endobronchial segmental allergen challenge in human atopic asthmatics to define the pattern of chemoattractant receptor expression on recruited T cells as well as the numbers of recruited CD1d-restricted NKT cells and levels of chemokines in the bronchoalveolar (BAL) fluid. CD1d-restricted NKT cells comprised only a small minority of BAL T cells before or after Ag challenge. BAL T cells were enriched in their expression of specific chemoattractant receptors compared with peripheral blood T cells prechallenge, including CCR5, CCR6, CXCR3, CXCR4, and BLT1. Surprisingly, following segmental allergen challenge, no chemoattractant receptor was specifically increased. However, CCR6 and CXCR3, which were expressed on virtually all CD4(+) BAL T cells prechallenge, were markedly decreased on all recruited BAL T cells following Ag challenge, suggesting that these receptors were internalized following encounter with ligand in the airway. Our data therefore suggests a role for CCR6 and CXCR3, in conjunction with other chemoattractant receptors, in the recruitment of inflammatory T cells into the BAL during the allergic asthmatic response.

Error Rates Among Clinical Pharmacists in Calculating the APACHE II Score

BACKGROUND

The Food and Drug Administration recently advocated the use of acuity scoring to determine those patients whose mortality benefits outweigh risks of adverse effects from drotrecogin alfa (activated). Many institutions have adopted an Acute Physiology and Chronic Health Evaluation (APACHE) II cutoff score of 25 (i.e., if > or = 25, administer the agent) as a component in determining eligibility for treatment with this agent. Concern is increasing that errors in the acquisition of APACHE scores can lead to prescribing errors with drotrecogin alfa (activated).

OBJECTIVE

To determine the ability of clinical pharmacists in ascertaining APACHE II scores.

METHODS

Fifteen clinical pharmacists calculated APACHE II scores for the clinical scenarios of three patients. End points were the pharmacists' APACHE II score calculation, decision to start drotrecogin alfa (activated) treatment, and evaluation of individual components of the APACHE II scores.

RESULTS

Of the 15 pharmacists, correct APACHE II scores were derived by nine (60%) pharmacists for patient no. 1 (APACHE score 44), by two (13%) pharmacists for patient no. 2 (APACHE score 22), and by two (13%) pharmacists for patient no. 3 (APACHE score 19). Scoring errors occurred in 32 of the 45 (71%) derivations. The pharmacists were significantly more likely to correctly prescribe drotrecogin alfa for the two patients with true APACHE scores of 19 and 44 than for the patient whose score was 22, which was closer to the prescribing cutoff score of 25 (both p<0.001, patient no. 1 vs no. 2, and patient no. 2 vs no. 3, Fisher exact test) All individual components of the score were correctly evaluated at least 80% of the time, except for mean arterial pressure, respiratory rate, and Glasgow Coma Scale score.

CONCLUSION

Caution must be used in applying results of APACHE II scores estimated by only one trained individual when deciding to administer or withhold drotrecogin alfa (activated).

Exertional heat illness and human gene expression

Microarray analysis of gene expression at the level of RNA has generated new insights into the relationship between cellular responses to acute heat shock in vitro, exercise, and exertional heat illness. Here we discuss the systemic physiology of exertional hyperthermia and exertional heat illness, and compare the results of several recent microarray studies performed in vitro on human cells subjected to heat shock and in vivo on samples obtained from subjects performing exercise or suffering from exertional heat injury. From these comparisons, a concept of overlapping component responses emerges. Namely, some of the gene expression changes observed in peripheral blood mononuclear cells during exertional heat injury can be accounted for by normal cellular responses to heat, exercise, or both; others appear to be specific to the disease state itself. If confirmed in future studies, these component responses might provide a better understanding of adaptive and pathological responses to exercise and exercise-induced hyperthermia, help find new ways of identifying individuals at risk for exertional heat illness, and perhaps even help find rational molecular targets for therapeutic intervention.

The PTGDR gene is not associated with asthma in 3 ethnically diverse populations

BACKGROUND

The prostanoid DP receptor (PTGDR) gene on chromosome 14q22.1 has been identified as an asthma susceptibility gene. A haplotype with decreased transcription factor binding and transcription efficiency was associated with decreased asthma susceptibility in African American and white subjects. The significance of PTGDR gene variants in asthma has yet to be determined in Latinos, the largest US minority population, nor has the association been replicated in other populations.

OBJECTIVE

To determine the role of PTGDR gene variants in asthma susceptibility and asthma-related traits among the Mexican, Puerto Rican, and African American populations.

METHODS

We determined whether single nucleotide polymorphisms (SNPs) and haplotypes in PTGDR were associated with asthma and asthma-related traits by family-based and cross-sectional cohort analyses in 336 Puerto Rican and 273 Mexican asthmatic trios and by case-control analysis among African American subjects with asthma and healthy controls (n = 352).

RESULTS

We identified 13 SNPs in the PTGDR gene, and 6 were further analyzed. There was no significant association between PTGDR variants and asthma by family-based or case-control analyses. SNPs -441C and -197C and haplotype TTT showed marginal association with asthma-related traits in Mexican subjects. SNP -441 genotype TT (P = .05) and haplotype TTT (P = .02) were associated with increased IgE levels in African Americans.

CONCLUSION

We conclude that the PTGDR gene is not a significant risk factor for asthma among Puerto Ricans, Mexicans, or African Americans.

CLINICAL IMPLICATIONS

Asthma candidate genes provide insights to pathophysiology and potentially new therapeutic targets, although the PTGDR gene was not found to be a significant risk factor for asthma in 3 populations.