Critical Illness Outcome Study: An Observational Study on Protocols and Mortality in Intensive Care Units

Antepartum Aspirin Administration Reduces Activin A and Cardiac Global Longitudinal Strain in Preeclamptic Women

Background Approximately 60% of women have Stage B heart failure 1 year after a preeclamptic delivery. Emerging evidence suggests that the profibrotic growth factor activin A, which has been shown to induce cardiac fibrosis and hypertrophy, is elevated in preeclampsia and may be inhibited by aspirin therapy. We hypothesized that preeclamptic women receiving aspirin would have lower activin A levels and reduced global longitudinal strain (GLS), a sensitive measure of cardiac dysfunction, than women who do not receive aspirin. To test our hypothesis, we performed a cohort study of women with preeclampsia or superimposed preeclampsia and compared activin A levels and GLS in parturients who did or did not receive aspirin. Methods and Results Ninety-two parturients were enrolled, of whom 25 (27%) received aspirin (81 mg/day) therapy. GLS, plasma activin A, and follistatin, which inactivates activin A, were measured. Women receiving aspirin therapy had lower median (interquartile range) levels of activin A (8.17 [3.70, 10.36] versus 12.77 [8.37, 31.25] ng/mL; P=0.001) and lower activin/follistatin ratio (0.59 [0.31, 0.93] versus 1.01 [0.64, 2.60] P=0.002) than women who did not receive aspirin, which also remained significant after multivariable analysis. Furthermore, GLS was worse in patients who did not receive aspirin (-19.84±2.50 versus -17.77±2.60%; P=0.03) despite no differences in blood pressure between groups. Conclusions Our study suggests that antepartum aspirin therapy reduced serum activin A levels and improved GLS in preeclamptic patients, suggesting that aspirin may mitigate the postpartum cardiac dysfunction seen in women with preeclampsia.

Association between hospital mortality and inspiratory airway pressures in mechanically ventilated patients without acute respiratory distress syndrome: a prospective cohort study

Background

Higher inspiratory airway pressures are associated with worse outcomes in mechanically ventilated patients with the acute respiratory distress syndrome (ARDS). This relationship, however, has not been well investigated in patients without ARDS. We hypothesized that higher driving pressures (ΔP) and plateau pressures (Pplat) are associated with worse patient-centered outcomes in mechanically ventilated patients without ARDS as well as those with ARDS.

Methods

Using data collected during a prospective, observational cohort study of 6179 critically ill participants enrolled in 59 ICUs across the USA, we used multivariable logistic regression to determine whether ΔP and Pplat at enrollment were associated with hospital mortality among 1132 mechanically ventilated participants. We stratified analyses by ARDS status.

Results

Participants without ARDS (n = 822) had lower average severity of illness scores and lower hospital mortality (27.3% vs. 38.7%; p <  0.001) than those with ARDS (n = 310). Average Pplat (20.6 vs. 23.9 cm H₂O; p <  0.001), ΔP (14.3 vs. 16.0 cm H₂O; p <  0.001), and positive end-expiratory pressure (6.3 vs. 7.9 cm H₂O; p <  0.001) were lower in participants without ARDS, whereas average tidal volumes (7.2 vs. 6.8 mL/kg PBW; p <  0.001) were higher. Among those without ARDS, higher ΔP (adjusted OR = 1.36 per 7 cm H₂O, 95% CI 1.14–1.62) and Pplat (adjusted OR = 1.42 per 8 cm H₂O, 95% CI 1.17–1.73) were associated with higher mortality. We found similar relationships with mortality among those participants with ARDS.

Conclusions

Higher ΔP and Pplat are associated with increased mortality for participants without ARDS. ΔP may be a viable target for lung-protective ventilation in all mechanically ventilated patients.

Evaluation of RBC Transfusion Practice in Adult ICUs and the Effect of Restrictive Transfusion Protocols on Routine Care

OBJECTIVE

Research supports the efficacy and safety of restrictive transfusion protocols to reduce avoidable RBC transfusions, but evidence of their effectiveness in practice is limited. This study assessed whether admission to an ICU with an restrictive transfusion protocol reduces the likelihood of transfusion for adult patients.

DESIGN

Observational study using data from the multicenter, cohort Critical Illness Outcomes Study. Patient-level analyses were conducted with RBC transfusion on day of enrollment as the outcome and admission to an ICU with a restrictive transfusion protocol as the exposure of interest. Covariates included demographics, hospital course (e.g., lowest hematocrit, blood loss), severity of illness (e.g., Sequential Organ Failure Assessment score), interventions (e.g., sedation/analgesia), and ICU characteristics (e.g., size). Multivariable logistic regression modeling assessed the independent effects of restrictive transfusion protocols on transfusions.

SETTING

Fifty-nine U.S. ICUs.

PATIENTS

A total of 6,027 adult ICU patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 59 study ICUs, 24 had an restrictive transfusion protocol; 2,510 patients (41.6%) were in an ICU with an restrictive transfusion protocol. The frequency of RBC transfusion among patients with severe (hematocrit, < 21%), moderate (hematocrit, 21-30%), and mild (hematocrit, > 30%) anemia in restrictive transfusion protocol ICUs was 67%, 19%, and 4%, respectively, compared with 60%, 14%, and 2% for those in ICUs without an restrictive transfusion protocol. Only 27% of transfusions were associated with a hematocrit less than 21%. Adjusting for confounding factors, restrictive transfusion protocols independently reduced the odds of transfusion in moderate anemia with an odds ratio of 0.59 (95% CI, 0.36-0.96) while demonstrating no effect in mild (p = 0.93) or severe (p = 0.52) anemia.

CONCLUSIONS

In this sample of ICU patients, transfusions often occurred outside evidence-based guidelines, but admission to an ICU with an restrictive transfusion protocol did reduce the risk of transfusion in moderately anemic patients controlling for patient and ICU factors. This study supports the effectiveness of restrictive transfusion protocols for influencing transfusions in clinical practice.

Protocols and Hospital Mortality in Critically Ill Patients: The United States Critical Illness and Injury Trials Group Critical Illness Outcomes Study

OBJECTIVE

Clinical protocols may decrease unnecessary variation in care and improve compliance with desirable therapies. We evaluated whether highly protocolized ICUs have superior patient outcomes compared with less highly protocolized ICUs.

DESIGN

Observational study in which participating ICUs completed a general assessment and enrolled new patients 1 day each week.

PATIENTS

A total of 6,179 critically ill patients.

SETTING

Fifty-nine ICUs in the United States Critical Illness and Injury Trials Group Critical Illness Outcomes Study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary exposure was the number of ICU protocols; the primary outcome was hospital mortality. A total of 5,809 participants were followed prospectively, and 5,454 patients in 57 ICUs had complete outcome data. The median number of protocols per ICU was 19 (interquartile range, 15-21.5). In single-variable analyses, there were no differences in ICU and hospital mortality, length of stay, use of mechanical ventilation, vasopressors, or continuous sedation among individuals in ICUs with a high versus low number of protocols. The lack of association was confirmed in adjusted multivariable analysis (p = 0.70). Protocol compliance with two ventilator management protocols was moderate and did not differ between ICUs with high versus low numbers of protocols for lung protective ventilation in acute respiratory distress syndrome (47% vs 52%; p = 0.28) and for spontaneous breathing trials (55% vs 51%; p = 0.27).

CONCLUSIONS

Clinical protocols are highly prevalent in U.S. ICUs. The presence of a greater number of protocols was not associated with protocol compliance or patient mortality.

Establishment of a prospective cohort of mechanically ventilated patients in five intensive care units in Lima, Peru: protocol and organisational characteristics of participating centres

INTRODUCTION

Mechanical ventilation is a cornerstone in the management of critically ill patients worldwide; however, less is known about the clinical management of mechanically ventilated patients in low and middle income countries where limitation of resources including equipment, staff and access to medical information may play an important role in defining patient-centred outcomes. We present the design of a prospective, longitudinal study of mechanically ventilated patients in Peru that aims to describe a large cohort of mechanically ventilated patients and identify practices that, if modified, could result in improved patient-centred outcomes and lower costs.

METHODS AND ANALYSIS

Five Peruvian intensive care units (ICUs) and the Medical ICU at the Johns Hopkins Hospital were selected for this study. Eligible patients were those who underwent at least 24 h of invasive mechanical ventilation within the first 48 h of admission into the ICU. Information on ventilator settings, clinical management and treatment were collected daily for up to 28 days or until the patient was discharged from the unit. Vital status was assessed at 90 days post enrolment. A subset of participants who survived until hospital discharge were asked to participate in an ancillary study to assess vital status, and physical and mental health at 6, 12, 24 and 60 months after hospitalisation, Primary outcomes include 90-day mortality, time on mechanical ventilation, hospital and ICU lengths of stay, and prevalence of acute respiratory distress syndrome. In subsequent analyses, we aim to identify interventions and standardised care strategies that can be tailored to resource-limited settings and that result in improved patient-centred outcomes and lower costs.

ETHICS AND DISSEMINATION

We obtained ethics approval from each of the four participating hospitals in Lima, Peru, and at the Johns Hopkins School of Medicine, Baltimore, USA. Results will be disseminated as several separate publications in different international journals.

Navigating the institutional review board approval process in a multicenter observational critical care study

OBJECTIVE

To characterize variation in the institutional review board application process of a multicenter, observational critical care study.

DESIGN, SETTING, AND SUBJECTS

Survey analysis of 36 investigators who applied for participation in the United States Critical Illness and Injury Trials Group: Critical Illness and Outcomes Study, an observational study of 69 adult ICUs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Analysis of investigator-specific characteristics, institutional review board process, application and approval dates, and level of difficulty in obtaining approval. Surveys were analyzed from 36 sites (95%) that applied for institutional review board approval. Level of review ranged from full board, expedited, to exempt. Seventy-five percent of applications were submitted by an experienced investigator while 25% were submitted by a less experienced investigator. Median time to institutional review board approval was 30 days (interquartile range, 14-54) and ranged from 5 days to 5.5 months. Time to approval was 29 days (interquartile range, 17-48) for applications submitted by an experienced investigator compared with 97 days (interquartile range, 25-159) for those submitted by a less experienced investigator (p = 0.08). Subjective level of difficulty was significantly higher for less experienced investigators (4 of 10; interquartile range, 2-8) vs experienced investigators (2 of 10; interquartile range, 1-3) (p = 0.04). Four sites cited institutional review board concern regarding waiver of consent as a major barrier to approval and were required to perform revisions or participate in board meetings regarding this concern.

CONCLUSIONS

In a multicenter, observational critical care study, significant variation was observed between sites in all aspects of the institutional review board evaluation and approval process. The level of difficulty was significantly higher for less experienced investigators with a trend toward longer time to institutional review board approval. Variation in institutional review board interpretation of waiver of informed consent regulations was cited as a major barrier to approval.

Structure, process, and annual ICU mortality across 69 centers: United States Critical Illness and Injury Trials Group Critical Illness Outcomes Study

OBJECTIVE

Hospital-level variations in structure and process may affect clinical outcomes in ICUs. We sought to characterize the organizational structure, processes of care, use of protocols, and standardized outcomes in a large sample of U.S. ICUs.

DESIGN

We surveyed 69 ICUs about organization, size, volume, staffing, processes of care, use of protocols, and annual ICU mortality.

SETTING

ICUs participating in the United States Critical Illness and Injury Trials Group Critical Illness Outcomes Study.

SUBJECTS

Sixty-nine intensivists completed the survey.

MEASUREMENTS AND MAIN RESULTS

We characterized structure and process variables across ICUs, investigated relationships between these variables and annual ICU mortality, and adjusted for illness severity using Acute Physiology and Chronic Health Evaluation II. Ninety-four ICU directors were invited to participate in the study and 69 ICUs (73%) were enrolled, of which 25 (36%) were medical, 24 (35%) were surgical, and 20 (29%) were of mixed type, and 64 (93%) were located in teaching hospitals with a median number of five trainees per ICU. Average annual ICU mortality was 10.8%, average Acute Physiology and Chronic Health Evaluation II score was 19.3, 58% were closed units, and 41% had a 24-hour in-house intensivist. In multivariable linear regression adjusted for Acute Physiology and Chronic Health Evaluation II and multiple ICU structure and process factors, annual ICU mortality was lower in surgical ICUs than in medical ICUs (5.6% lower [95% CI, 2.4-8.8%]) or mixed ICUs (4.5% lower [95% CI, 0.4-8.7%]). We also found a lower annual ICU mortality among ICUs that had a daily plan of care review (5.8% lower [95% CI, 1.6-10.0%]) and a lower bed-to-nurse ratio (1.8% lower when the ratio decreased from 2:1 to 1.5:1 [95% CI, 0.25-3.4%]). In contrast, 24-hour intensivist coverage (p = 0.89) and closed ICU status (p = 0.16) were not associated with a lower annual ICU mortality.

CONCLUSIONS

In a sample of 69 ICUs, a daily plan of care review and a lower bed-to-nurse ratio were both associated with a lower annual ICU mortality. In contrast to 24-hour intensivist staffing, improvement in team communication is a low-cost, process-targeted intervention strategy that may improve clinical outcomes in ICU patients.

United States Critical Illness and Injury Trials Group

The United States Critical Illness and Injury Trials (USCIIT) Group is an inclusive, grassroots "network of networks" with the dual missions of fostering investigator-initiated hypothesis testing and developing recommendations for strategic plans at a national level. The USCIIT Group's transformational approach enlists multidisciplinary investigative teams across institutions, critical illness and injury professional organizations, federal agencies that fund clinical and translational research, and industry partners. The USCIIT Group is endorsed by all major critical illness and injury professional organizations spanning the specialties of anesthesiology, emergency medicine, internal medicine, neurology, nursing, pediatrics, pharmacy and nutrition, surgery and trauma, and respiratory and physical therapy. Recent successes provide the opportunity to significantly increase the dialogue necessary to advance clinical and translational research on behalf of our community. More than 200 investigators are now involved across > 30 academic and community hospitals. Collectively, USCIIT Group investigators have enrolled > 10,000 patients from academic and community hospitals in studies during the last 3 years. To keep our readership "ahead of the curve," this article provides a vision for critical illness and injury research based on (1) programmatic organization of large-scale, multicentered collaborative studies and (2) annual strategic planning at a national scale across disciplines and stakeholders.

Protocols in the management of critical illness

Care of the critically ill patient is becoming increasingly complex. Protocols, which standardize care of patients with similar diseases, represent a potential solution to managing multiple simultaneous problems in critically ill patients. In this article, we examine the advantages and disadvantages to care protocolization, and posit that careful and thoughtful implementation of protocols is likely to benefit patients. We also discuss the potential for unintended consequences, and even harm, with protocolization in critically ill patients using the Critical Illness Outcomes Study as a model to examine the effects of protocolization in large populations of intensive care patients.