Critical Care Setting Research Articles

Use of Rounding Checklists to Improve Communication and Collaboration in the Adult Intensive Care Unit: An Integrative Review.

Intensive care units are complex settings that require effective communication and collaboration among professionals in many disciplines. Rounding checklists are frequently used during interprofessional rounds and have been shown to positively affect patient outcomes. To identify and summarize the evidence related to the following practice question: In an adult intensive care unit, does the use of a rounding checklist during interprofessional rounds affect the perceived level of staff collaboration or communication? An integrative review was performed to address the practice question. No parameters were set for publication year or specific study design. Studies were included if they were set in adult intensive care units, involved the use of a structured rounding checklist, and had measured outcomes that included staff collaboration, communication, or both. Seven studies with various designs were included in the review. Of the 7 studies, 6 showed that use of rounding checklists improved staff collaboration, communication, or both. These results have a variety of practice implications, including the potential for better patient outcomes and staff retention. Given the complexity of the critical care setting, optimizing teamwork is essential. The evidence from this review indicates that the use of a relatively simple rounding checklist tool during interprofessional rounds can improve perceived collaboration and communication in adult intensive care units.

The Predictors of Perceived Barriers and Facilitators of Applying Sepsis Six Guidelines Among Critical Care Nurses.

Sepsis is a life-threatening condition that demands quick and cautious interventions from nurses, as they are the frontline caregivers, so they are essential in recognizing early signs of sepsis, initiating prompt healthcare interventions, and providing comprehensive care to improve patient outcomes. This study aimed to examine the predictors of perceived barriers and facilitators of applying evidence-based sepsis guidelines among critical care nurses. This cross-sectional descriptive study was conducted on a convenience sample of 180 nurses working in critical care settings (ICU, critical careunit, ED, burning unit, dialysis unit) at a university hospital. A valid and reliable questionnaire was used to examine the predictors of perceived barriers and facilitators of applying evidence-based sepsis guidelines among critical care nurses. This study revealed that the main barriers faced by critical care nurses are lack of sepsis recognition during observational rounds and delay in sepsis diagnosis by medical staff. For the most common facilitators of applying Sepsis Six guidelines, the participating nurses reported the presence of a written tool/protocol for sepsis identification and management. The study emphasized the importance of the presence of evidence-based protocols for sepsis assessment and management and nurses' compliance with guidelines. Ongoing education training for nurses and providing step-by-step written checklists are a cornerstone to improving nurses' knowledge and the practical skills of early identification and management of sepsis.

A Comprehensive Review of Prone Ventilation in the Intensive Care Unit: Challenges and Solutions.

This comprehensive review explores the intricate landscape of prone ventilation in the intensive care unit (ICU), spanning physiological rationale, challenges in implementation, psychosocial impacts, technological innovations, economic considerations, barriers to adoption, and implications for clinical practice. The physiological benefits of prone positioning, including improved oxygenation and lung compliance, are discussed alongside the challenges of patient selection and technical complexities. The psychosocial impact on patients and caregivers, as well as the economic implications for healthcare systems, adds a crucial dimension to the analysis. The review also delves into innovative technologies, such as advanced monitoring and automation, shaping the landscape of prone ventilation. Moreover, it addresses the barriers to widespread adoption and outlines strategies to overcome resistance, emphasizing the need for a comprehensive and collaborative approach. The implications for clinical practice underscore the importance of evidence-based guidelines, ongoing education, and a holistic patient-centered care approach. The conclusion highlights the call to action for further research to refine protocols and technology, ultimately optimizing the application of prone ventilation in critical care settings.

Optimal Treatment Strategies for Critical Patients with Deep Reinforcement Learning

Personalized clinical decision support systems are increasingly being adopted due to the emergence of data-driven technologies, with this approach now gaining recognition in critical care. The task of incorporating diverse patient conditions and treatment procedures into critical care decision-making can be challenging due to the heterogeneous nature of medical data. Advances in Artificial Intelligence (AI), particularly Reinforcement Learning (RL) techniques, enables the development of personalized treatment strategies for severe illnesses by using a learning agent to recommend optimal policies. In this study, we propose a Deep Reinforcement Learning (DRL) model with a tailored reward function and an LSTM-GRU-derived state representation to formulate optimal treatment policies for vasopressor administration in stabilizing patient physiological states in critical care settings. Using an ICU dataset and the Medical Information Mart for Intensive Care (MIMIC-III) dataset, we focus on patients with Acute Respiratory Distress Syndrome (ARDS) that has led to Sepsis, to derive optimal policies that can prioritize patient recovery over patient survival. Both the DDQN ( RepDRL-DDQN ) and Dueling DDQN ( RepDRL-DDDQN ) versions of the DRL model surpass the baseline performance, with the proposed model’s learning agent achieving an optimal learning process across our performance measuring schemes. The robust state representation served as the foundation for enhancing the model’s performance, ultimately providing an optimal treatment policy focused on rapid patient recovery.

The Effect of Delay Following the Clinical Decision to Perform Tracheostomy in the Critical Care Setting.

Tracheostomy in patients who are critically ill is generally performed due to prolonged mechanical ventilation and expected extubation failure. However, tracheostomy criteria and ideal timing are poorly defined, including equivocal data from randomized controlled trials and median intubation to tracheostomy times that range from 7-21 d. However, a consistent finding is that only ∼50% of late tracheostomy groups actually undergo tracheostomy, with non-performance due to recovery or clinical deterioration. Unlike in many jurisdictions, elective surgical procedures in our institution require a court-appointed guardian, which necessitates an approximately 1-week delay between the decision to perform tracheostomy and surgery. This offers a unique opportunity to observe patients with potential tracheostomy during a delay between the decision and the performance. ICU patients who were ventilated were identified for inclusion retrospectively by an application for guardianship relating to tracheostomy, the intention-to-treat point. The main outcomes of tracheostomy, extubation, or death/palliative care after inclusion were noted. Demographics, outcomes, and event timing were compared for the 3 outcome groups. Tracheostomy-related guardianship requests were made for 388 subjects. Of these, 195 (50%) underwent tracheostomy, whereas 127 (33%) were extubated and 66 (17%) either died before tracheostomy (46 [12%]) or were transitioned to palliative care (20 [5%]). The median time (interquartile range) from guardianship request until a defining event was the following: 6.2 (4.0-11) d for tracheostomy, 5.0 (2.9-8.2) d for extubation (P < .001 as compared to tracheostomy group), and 6.5 (2.5-11) d for death/palliative care (P = .55 as compared to tracheostomy). Neurological admissions were more common in the tracheostomy group and less common in the palliative group. Other admission demographics and hospitalization characteristics were similar. Hospital mortality was higher for subjects undergoing tracheostomy (58/195 [30%]) versus extubation (24/127 [19%]) (P = .03). Delay in performing tracheostomy due to legal requirements was associated with a 50% decrease in the need for tracheostomy. This suggests that decision-making with regard to ideal tracheostomy timing could be improved, saving unnecessary procedures.

Hemophagocytic Lymphohistiocytosis: an updated overview and management approach in the critical care setting

Hemophagocytic lymphohistiocytosis (HLH) constitutes a rare and potentially life-threatening immunological syndrome. It manifests in both primary (genetic) and secondary (acquired) forms, exhibiting a diverse range of clinical and laboratory features, thereby posing challenges to accurate diagnosis, particularly within critical care settings. Early identification and intervention are of vital importance for improving patient survival. This article comprehensively explores the existing literature, encompassing the classification, pathophysiology, and clinical presentation of HLH. Special emphasis is placed on identifying prognostic factors, organ failure, and associated complications. Moreover, a detailed narrative of proposed management strategies, including immuno- and myelosuppressive options, is presented. Further research directions are suggested to enhance the understanding and treatment of this complex disorder.

Scope of a short &amp; obese patient for thymoma surgery with the risk of difficulty in weaning from general anaesthesia

Obese patients had more difficulty with tracheal intubation and a higher incidence of post-extubation stridor. Obesity is such a ubiquitous issue in our culture, and it is a significant risk factor for many diseases, thus it is not surprising that many obese patients are treated in ICU. The objective of this article is to explore challenges for short, obese patients (Little’s) in the critical care setting. Obese patients have a strong correlation between lung function and body fat distribution, with greater impairment when fat accumulates in the chest and abdomen. Mediastinal masses, particularly those located in the anterior mediastinum, can cause perioperative morbidity and mortality by causing major airway and vascular compression, which may be exacerbated under general anesthesia.

The impact of preceptorship on the newly qualified nurse and preceptors working in a critical care environment: An integrative literature review.

Preceptorship has been found to be effective in supporting Newly Qualified Nurses (NQNs) during their transition into challenging environments, particularly in addressing issues related to confidence and anxiety. Effective preceptorship is an element of best practice and essential to support NQNs' transition into the critical care setting. However, the impact of preceptorship on NQNs and their preceptors in critical care units is yet to be completely understood. To review the impact of preceptorship on NQNs and preceptors working in a critical care environment. An integrative literature review of the literature. The review employed Whittemore and Knafl's (2005) five-stage integrative review approach. Three databases (MEDLINE, CINAHL and PsycINFO) were searched for papers published between January 2010 and May 2022. The PRISMA framework was used to guide the search and screening. Thematic analysis was used to extract, organize and analyse the data. Nine studies were included in this review. Reflective thematic analysis revealed three themes, with four related subthemes. Preceptorship has an impact on the development of the NQNs and preceptors' 'nurturing' relationship. NQNs develop their knowledge, competence and confidence when experiencing supportive preceptorship. Meanwhile, preceptors experience a combination of increased workload and opportunities for learning and professional development as a result of preceptorship. There is evidence of the impact of preceptorship on learning and professional development for both NQNs and preceptors, but this is a complex phenomenon and further research is required to understand this area more fully. In nursing practice, it is well-established that Newly Qualified Nurses (NQNs) often face heightened levels of anxiety and a lack of confidence when embarking on their careers, particularly in the demanding and stressful environment of critical care units. This review holds particular significance in the realm of clinical practice as it delves into the pivotal role of preceptorship in nurturing the professional growth and development of NQNs within the challenging domain of critical care. Effective preceptorship, as an essential component of best practice, plays a pivotal role in aiding NQNs' transition into critical care settings.

Feasibility of Fluid Responsiveness Assessment in Patients at Risk for Increased Intracranial Pressure.

Background: Effective fluid management is important for patients at risk of increased intracranial pressure (ICP). Maintaining constant cerebral perfusion represents a challenge, as both hypovolemia and fluid overload can severely impact patient outcomes. Fluid responsiveness tests, commonly used in critical care settings, are often deemed potentially hazardous for these patients due to the risk of disrupting cerebral perfusion. Methods: This single-center, prospective, clinical observational study enrolled 40 patients at risk for increased ICP, including those with acute brain injury. Informed consent was obtained from each participant or their legal guardians before inclusion. The study focused on the dynamics of ICP and cerebral perfusion pressure (CPP) changes during the Passive Leg Raise Test (PLRT) and the End-Expiratory Occlusion Test (EEOT). Results: The results demonstrated that PLRT and EEOT caused minor and transient increases in ICP, while consistently maintaining stable CPP. EEOT induced significantly lower ICP elevations, making it particularly suitable for use in high-risk situations. Conclusions: PLRT and EEOT can be considered feasible and safe for assessing fluid responsiveness in patients at risk for increased ICP. Notably, EEOT stands out as a preferred method for high-risk patients, offering a dependable strategy for fluid management without compromising cerebral hemodynamics.

Emergency Management of Curling Ulcers: Exploring Strategies for Timely Diagnosis and Intervention in Critical Care Settings

Emergency Management of Curling Ulcers: Exploring Strategies for Timely Diagnosis and Intervention in Critical Care Settings

Emergency Management of Curling Ulcers: Exploring Strategies for Timely Diagnosis and Intervention in Critical Care Settings

Emergency Management of Curling Ulcers: Exploring Strategies for Timely Diagnosis and Intervention in Critical Care Settings

Emergency Management of Curling Ulcers: Exploring Strategies for Timely Diagnosis and Intervention in Critical Care Settings

Emergency Management of Curling Ulcers: Exploring Strategies for Timely Diagnosis and Intervention in Critical Care Settings

Validation of deep learning models for cuffless blood pressure estimation on a large benchmarking dataset

Objective: This study aims to evaluate the effectiveness of deep learning techniques in estimating cuffless blood pressure (BP) across a diverse patient population in intensive care units (ICUs). Methods: A comprehensive ICU benchmarking dataset encompassing 2,154 patients with a wide demographic range (18-97 years old) and varied cardiovascular status was employed to validate several deep learning models in predicting continuous BP waveforms. Three methods were developed to enhance the model's generalizability to this heterogeneous dataset. Ten-fold subject-independent cross-validation was performed and the model performance was assessed through mean absolute error (MAE), Pearson’s correlation coefficient (PCC), and compared with significance analysis. Results: The UTransBPNet_Demo_In model, which incorporated demographic and physiological signals as inputs, achieved a PCC of 0.89 and a MAE of 10.38 mmHg in predicting arterial BP waveforms, demonstrating the highest tracking capability among all models. Notably, the performance of UTransBPNet_Demo_In remained robust across variations in demographic and cardiovascular status. Conclusion: The UTransBPNet_Demo_In model demonstrates robust predictive capabilities across a broad spectrum of demographics and cardiovascular conditions. Although the performance still needs further improvement, this study offers a benchmark in the field of cuffless BP monitoring in critical care settings for future studies.

How to follow the guidelines, when the appropriate fluid is missing?

Intravenous maintenance fluid therapy (IV-MFT) is probably the most prescribed drug in paediatric hospital care. Recently paediatric societies have produced evidence-based practice guidelines that recommend the use of balanced isotonic fluid when prescribing IV-MFT in both acute and critical paediatric care. Unfortunately, the applicability of these guidelines could be called into question when a ready-to-use glucose-containing balanced isotonic fluid is not available. The main objective of this study was to describe the availability of glucose-containing balanced isotonic fluids in European and Middle Eastern paediatric acute and critical care settings. This work is an ancillary study of the survey dedicated to IV-MFT practices in the paediatric acute and critical care settings in Europe and Middle East, a cross-sectional electronic 27-item survey, emailed in April-May 2021 to paediatric critical care physicians across 34 European and Middle East countries. The survey was developed by an expert multi-professional panel within the European Society of Peadiatric and Neonatal Intensive Care (ESPNIC). Balanced isotonic fluid with glucose 5% was available for only 32/153 (21%) responders. Balanced isotonic fluid with glucose 5% was consistently available in the UK (90%) but not available in France, Greece, The Netherlands and Turkey. Conclusion: Ready-to-use isotonic balanced IV solutions containing glucose in sufficient amount exist but are inconsistently available throughout Europe. National and European Medication Safety Incentives should guarantee the availability of the most appropriate and safest IV-MFT solution for all children. What is Known: • Intravenous maintenance fluid therapy (IV-MFT) is probably the most prescribed drug in paediatric hospital care. • Balanced isotonic fluid is recommended when prescribing IV-MFT in both acute and critical paediatric care. What is New: • Balanced isotonic fluid with glucose 5% is available for less than 25% of the prescribers in Europe and the Middle East.Availability of balanced isotonic fluid with glucose 5% varies from one country to another but can also be inconsistent within the same country. • Clinicians who have access to a ready-to-use balanced isotonic fluid with glucose 5% are more likely to consider its use than clinicians who do not have access to such an IV solution.

Clinical pharmacist interventions in an intensive care unit reduces ICU mortality at a tertiary hospital in Dubai, United Arab Emirates

BackgroundDrug-related problems (DRPs) are prevalent in critical care settings and can be life-threatening. Involving clinical pharmacists (CP) within the critical care team is recommended to optimize therapy and improve patient survival. ObjectiveTo classify DRPs identified by a CP in the Intensive Care Unit (ICU) and to assess the impact of CP interventions accepted by physicians on the length of ICU stay and in-hospital survival. MethodsThis study was conducted prospectively at the Medical ICU of Rashid Hospital, a tertiary hospital in Dubai, over a 16-month period from September 2021 to December 2022. The study included patients admitted to ICU during the study period. CP interventions were documented, and DRPs were classified using the modified Pharmaceutical Care Network Europe V.9.1. ResultsDuring the study period, 1004 interventions were recommended for 200 patients. The majority of these interventions, 92% (n = 922), received physician acceptance, and 82% (n = 820) were fully implemented by the physician. In total, 1033 drug-related problems (DRPs) were identified, with a median of 3 DRPs per patient. The most common DRPs was drug selection (61%), followed by dose selection (22%). There were 337 DRPs related to antimicrobial agents. Interestingly, we noted that when we adjusted for patients' demographic data and the Glasgow Coma Scale severity score, patients who received >4 implemented interventions exhibited lower cumulative hazard of death within 90 days of their ICU stay in comparison to their counterparts (adjusted Hazard Ratio: 0.10, 95% CI of 0.02–0.41; P = 0.027). ConclusionThe study emphasizes the critical role of CP in the ICU, addressing DRPs, and enhancing overall patient care. Furthermore, it highlights the potential impact of pharmacist interventions in improving patient survival outcomes. This underscores the importance of implementing CP services in ICUs across the UAE.

The impact of different co-morbidities on clinical outcomes and resource utilization in critically ill burn and surgical patients: A population-based analysis of social determinants of health

BackgroundThis study aims to establish the significance of social determinants of health and prevalent co-morbidities on multiple indicators for quality of care in patients admitted to the Burn and Surgical Intensive Care Unit (ICU). MethodsWe performed a retrospective analysis of population group data for patients admitted at the Burn and Surgical ICU from January 1, 2016, to November 18, 2019. The primary outcomes were length of hospital stay (LOS), mortality, 30-day readmission, and hospital charges. Pearson's chi-square test for categorical variables and t-test for continuous variables were used to compare population health groups. ResultsWe analyzed a total of 487 burn and 510 surgical patients. When comparing ICU patients, we observed significantly higher mean hospital charges and length of stay (LOS) in BICU v. SICU patients with a history of mental health ($93,259.40 v. $50,503.36, p = 0.013 and 16.28 v. 9.16 days, p = 0.0085), end-stage-renal-disease (ESRD) ($653,871.05 v. $75,746.35, p = 0.0047 and 96.15 v. 17.53 days, p = 0.0104), sepsis ($267,979.60 v. $99,154.41, p = <0.001 and 39.1 v. 18.42 days, p = 0.0043), and venous thromboembolism (VTE) ($757,740.50 v. $117,816.40, p = <0.001 and 93.11 v. 20.21 days, p = 0.002). Also, higher mortality was observed in burn patients with ESRD, ST-Elevation Myocardial Infarction (STEMI), sepsis, VTE, and diabetes mellitus. 30-day-readmissions were greater among burn patients with a history of mental health, drug dependence, heart failure, and diabetes mellitus. ConclusionsOur study provides new insights into the variability of outcomes between burn patients treated in different critical care settings, underlining the influence of comorbidities on these outcomes. By comparing burn patients in the BICU with those in the SICU, we aim to highlight how differences in patient backgrounds, including the quality of care received, contribute to these outcomes. This comparison underscores the need for tailored healthcare strategies that consider the unique challenges faced by each patient group, aiming to mitigate disparities in health outcomes and healthcare spending. Further research to develop relevant and timely interventions that can improve these outcomes.

Adherence to a restrictive red blood cell transfusion strategy in critically ill patients: An observational study.

Randomized controlled trials relatively consistently show that restrictive red blood cell (RBC) transfusion strategies are safe and associated with similar outcomes compared to liberal transfusion strategies in critically ill patients. Based on these data, the general threshold for RBC transfusion was changed to 70 g/L at a 9-bed tertiary level intensive care unit in September 2020. Implementation measures included lectures, webinars and feedback during clinical practice. The aim of this study was to investigate how implementation of a restrictive transfusion strategy influenced RBC usage, haemoglobin trigger levels and adherence to prescribed trigger levels. In this registry-based, observational study, critically ill adult patients without massive bleeding were included and divided into a pre-cohort, with admissions prior to the change of transfusion strategy, and a post-cohort, with admissions following the change of transfusion strategy. These cohorts were compared regarding key RBC transfusion-related variables. In total 5626 admissions were included in the analyses (pre-cohort n = 4373, post-cohort n = 1253). The median volume (interquartile range, IQR) of RBC transfusions per 100 admission days, in the pre-cohort was 6120 (4110-8110) mL versus 3010 (2890-4970) mL in the post-cohort (p < .001). This corresponds to an estimated median saving of 1128 € per 100 admission days after a restrictive RBC transfusion strategy was implemented. In total, 26% of the admissions in the pre-cohort and 19% in the post-cohort (p < .001) received RBC transfusion(s) during days 0-10. Both median (IQR) prescribed trigger levels (determined by intensivist) and actual haemoglobin trigger levels (i.e., levels prior to actual administration of transfusion) were higher in the pre- versus post-cohort (90 [80-100] vs. 80 [72-90] g/L, p < .001 and 89 [82-96] g/L vs. 83 [79-94], p < .001, respectively). Percentage of days without compliance with the prescribed transfusion trigger was higher in the pre-cohort than in the post-cohort (23% vs. 14%, p < .001). Sensitivity analyses, excluding patients with traumatic brain injury, ischemic heart disease and COVID-19 demonstrated similar results. Implementation of a restrictive transfusion trigger in a critical care setting resulted in lasting decreased RBC transfusion use and costs, decreased prescribed and actual haemoglobin trigger levels and improved adherence to prescribed haemoglobin trigger levels.

A detailed review of critical illness related to pregnancy

Critical illness during pregnancy refers to severe medical conditions that can endanger the health and life of the pregnant woman and the developing fetus. Using critical illness during pregnancy as a topic for a review article can provide valuable insights into the challenges, management strategies, and outcomes associated with high-risk pregnancies. Pregnancy is a unique and complex physiological state that can challenge obstetricians and intensivists. Despite the advances in prenatal care, certain critical pregnancy illnesses are associated with significant feto-maternal morbidity and mortality. Maternal complications arise from abnormalities in physiological changes of pregnancy. This section highlights the common yet severe pregnancy complexities, pathophysiology, clinical manifestations, diagnosis, and management in critical care settings to optimize maternal and fetal outcomes. Some of the frequently encountered critical pregnancy illnesses are preeclampsia, eclampsia, HELLP syndrome, amniotic fluid embolism, peripartum cardiomyopathy, placental abruption, postpartum hemorrhage, and ectopic pregnancy. Each condition is discussed separately, further insinuating the need for timely diagnosis and treatment. This article also reviews the current treatment strategies, including blood pressure management, supportive care, and surgical intervention in obstetric hemorrhage and rupture. Critical care in pregnancy warrants profound vigilance and an adept, intensive, multidisciplinary approach, as prompt recognition and intervention decrease mortality and carry lifelong implications for both the mother and child.

Foot drop in critically ill patients: a narrative review of an elusive complication with intricate implications for recovery and rehabilitation.

Foot drop is a condition characterized by the inability to lift the foot upwards towards the shin bone. This condition may affect a proportion of critically ill patients, impacting on their recovery after the acute phase of the illness. The occurrence of foot drop in critical care patients may result from various underlying causes, including neurological injuries, muscular dysfunction, nerve compression, or vascular compromise. Understanding the etiology and assessing the severity of foot drop in these patients is essential for implementing appropriate management strategies and ensuring better patient outcomes. In this comprehensive review, we explore the complexities of foot drop in critically ill patients. We search for the potential risk factors that contribute to its development during critical illness, the impact it has on patients' functional abilities, and the various diagnostic techniques adopted to evaluate its severity. Additionally, we discuss current treatment approaches, rehabilitation strategies, and preventive measures to mitigate the adverse effects of foot drop in the critical care setting. Furthermore, we explore the roles of critical care physical therapists, neurologists, and other healthcare professionals in the comprehensive care of patients with foot drop syndrome and in such highlighting the importance of a multidisciplinary approach.

Usability Testing of Situation Awareness Clinical Decision Support in the Intensive Care Unit.

Our objective was to evaluate the usability of an automated clinical decision support (CDS) tool previously implemented in the pediatric intensive care unit (PICU) to promote shared situation awareness among the medical team to prevent serious safety events within children's hospitals. We conducted a mixed-methods usability evaluation of a CDS tool in a PICU at a large, urban, quaternary, free-standing children's hospital in the Midwest. Quantitative assessment was done using the system usability scale (SUS), while qualitative assessment involved think-aloud usability testing. The SUS was scored according to survey guidelines. For think-aloud testing, task times were calculated, and means and standard deviations were determined, stratified by role. Qualitative feedback from participants and moderator observations were summarized. Fifty-one PICU staff members, including physicians, advanced practice providers, nurses, and respiratory therapists, completed the SUS, while ten participants underwent think-aloud usability testing. The overall median usability score was 87.5 (interquartile range: 80-95), with over 96% rating the tool's usability as "good" or "excellent." Task completion times ranged from 2 to 92 seconds, with the quickest completion for reviewing high-risk criteria and the slowest for adding to high-risk criteria. Observations and participant responses from think-aloud testing highlighted positive aspects of learnability and clear display of complex information that is easily accessed, as well as opportunities for improvement in tool integration into clinical workflows. The PICU Warning Tool demonstrates good usability in the critical care setting. This study demonstrates the value of postimplementation usability testing in identifying opportunities for continued improvement of CDS tools.