Methemoglobinemia screening and treatment in tank warfare survivors.

INTRODUCTION: Methemoglobinemia, characterized by the conversion of functional hemoglobin to methemoglobin, can significantly impede tissue oxygenation. Prompt diagnosis and treatment of methemoglobinemia are critical to optimizing clinical outcomes. Although the underlying etiology of methemoglobinemia is often attributed to a medication reaction or chemical exposure, its association with battlefield trauma remains underexplored. This case series explores the presence of methemoglobinemia in nine soldiers evacuated from tanks targeted by explosives, shedding new light on screening needs and treatment strategies. CASES DESCRIPTION: Nine combat trauma patients with methemoglobinemia were admitted to Soroka Medical Center over a two-month period. Detailed case descriptions illustrate the diverse presentations and treatment responses. Notably, the administration of methylene blue resulted in rapid methemoglobin reductions and an improvement in oxygenation without any observed side effects. DISCUSSION: This series highlights an unexpected consequence of an explosion within an armored fighting vehicle and the challenges related to standard pulse oximetry interpretation and accuracy in the presence of methemoglobinemia, emphasizing the need for vigilant monitoring and co-oximetry utilization. Additionally, the coexistence of carboxyhemoglobin further warrants attention due to its synergistic and deleterious effects on oxygen delivery. Collaborative efforts with military authorities should aim to explore the underlying mechanisms associated with trauma and methemoglobinemia and optimize battlefield care. CONCLUSION: This case series underscores the significance of methemoglobinemia screening in combat trauma patients, and advocates for systematic co-oximetry utilization and methylene blue availability in combat zones. Early detection and intervention of methemoglobinemia in combat soldiers are often difficult in the context of battlefield injuries but are necessary to mitigate the potentially fatal consequences of this condition.

Establishing a 3-Tesla Magnetic Resonance Imaging Method for Assessing Diffuse Axonal Brain Injury in Rats.

Traumatic brain injury (TBI) significantly contributes to death and disability worldwide. However, treatment options remain limited. Here, we focus on a specific pathology of TBI, diffuse axonal brain injury (DABI), which describes the process of the tearing of nerve fibers in the brain after blunt injury. Most protocols to study DABI do not incorporate a specific model for that type of pathology, limiting their ability to identify mechanisms and comorbidities of DABI. In this study, we developed a magnetic resonance imaging (MRI) protocol for DABI in a rat model using a 3-T clinical scanner. We compared the neuroimaging outcomes with histologic and neurologic assessments. In a sample size of 10 rats in the sham group and 10 rats in the DABI group, we established neurological severity scores before the intervention and at 48 h following DABI induction. After the neurological evaluation after DABI, all rats underwent MRI scans and were subsequently euthanized for histological evaluation. As expected, the neurological assessment showed a high sensitivity for DABI lesions indicated using the ß-APP marker. Surprisingly, however, we found that the MRI method had greater sensitivity in assessing DABI lesions compared to histological methods. Out of the five MRI parameters with pathological changes in the DABI model, we found significant changes compared to sham rats in three parameters, and, as shown using comparative tests with other models, MRI was the most sensitive parameter, being even more sensitive than histology. We anticipate that this DABI protocol will have a significant impact on future TBI and DABI studies, advancing research on treatments specifically targeted towards improving patient quality of life and long-term outcomes.

The use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in Civilian Trauma in an Israeli Level 1 Trauma Center.

BACKGROUND: Massive, non-compressible bleeding is a leading cause of preventable trauma mortality. Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is a minimally invasive procedure in which a balloon catheter is maneuvered into the aorta to temporarily occlude large vessels and enable stabilization of the exsanguinating patient. OBJECTIVES: To present experiences in assimilating REBOA at a single level 1 trauma center in Israel, to evaluate the technical aspects of the procedure, and to describe patient characteristics and outcomes. METHODS: This retrospective cohort study comprised civilians admitted with hemorrhagic shock to our trauma department who were treated with REBOA between November 2017 and July 2021. Descriptive statistics of the patients, characteristics of the injuries and patient outcomes are presented. RESULTS: The study included 22 patients (median age 30.1 years, 21 male). The mean systolic blood pressure (SBP) before REBOA inflation was 59.6 ± 11.4 mmHg, and the mean SBP measured after the procedure was 115.2 ± 26.3 mmHg. In 20 patients (91%), the SBP was normalized (> 90 mmHg) shortly after inflation of the balloon, and they survived the treatment in the trauma department; 15 (75%) survived the first 30 days. CONCLUSIONS: REBOA is an effective method for the initial resuscitation and hemorrhage control of patients with massive, non-compressible bleeding and is relatively easy to assimilate in a hospital. The achievement of immediate normalization of SBP enables medical personnel to correct physiological parameters and obtain accurate imaging before proceeding to the operating theater.

Vasopressors and Mean Arterial Pressure in Septic Shock: Do We Bend the Rules for Young Adults?

BACKGROUND: Younger patient age and relatively good prognosis have been described as factors that may increase caregiver motivation in treating patients with septic shock in the intensive care unit (ICU). OBJECTIVES: To examine whether clinical teams tended to achieve unnecessarily higher map arterial pressure (MAP) values in younger patients. METHODS: We conducted a population-based retrospective cohort study of patients presenting with septic shock who were treated with noradrenaline and hospitalized in a general ICU between 2006 and 2018. The patients were classified into four age groups: 18-45 (n=129), 46-60 (n=96), 61-75 (n=157), and older than 75 years (n=173). Adjusted linear mixed models and locally weighted scatterplot smoothing (LOWESS) curves were used to assess associations and potential non-linear relationships, respectively, of age group with MAP and noradrenaline dosage. RESULTS: The cohort included 555 patients. An inverse relation was observed between average MAP value and age. Among patients aged 18-45 years, the average MAP was 4.7 mmHg higher (95% confidence interval 3.4-5.9) than among patients aged > 75 years (P-value <0.001) after adjustment for sex, death in the intensive care unit, and Sequential Organ Failure Assessment scores. CONCLUSIONS: Among patients with septic shock, the titration of noradrenaline by staff led to a higher average MAP for younger patients. Although the MAP target is equal for all age groups, staff may administer noradrenaline treatment according to a higher target of MAP due to attitudes toward patients of different ages, despite any evidence that such practice is beneficial.

Serum Albumin Levels as a Predictor of Mortality in Patients with Sepsis: A Multicenter Study.

BACKGROUND: Low serum albumin is known to be associated with mortality in sepsis, as it reflects effects of nutrition, catabolism, and edema. OBJECTIVES: To examine the association of albumin levels with in-hospital mortality in adults with sepsis, stratified by age groups. METHODS: This nationwide retrospective cohort study comprised patients admitted with sepsis to intensive care units in seven tertiary hospitals during 2003-2011. Only patients with available serum albumin levels at hospital admission and one week after were included. Patients with an intra-abdominal source of sepsis were excluded. The association between sepsis and mortality was analyzed using multivariate logistic regression models. RESULTS: The study included 3967 patients (58.7% male, median age 69 years). Mean serum albumin levels were 3.1 ± 0.7 g/dl at admission and 2.4 ± 0.6 g/dl one week later. In a multivariate logistic regression model, serum albumin one week after admission was inversely associated with in-hospital mortality (odds ratio [OR] 0.64, 95% confidence interval 0.55-0.73 per 1 g/dl). In an age-stratified analysis, the association was stronger with younger age (OR 0.44 for patients aged < 45 years, 0.60 for patients aged 45-65 years, and 0.67 for patients aged > 65 years). Serum albumin on admission was not associated with in-hospital mortality. CONCLUSIONS: The decline in serum albumin one week after admission is a stronger predictor of mortality in younger patients. Older patients might have other reasons for low serum albumin, which reflect chronic co-morbidity rather than acuity of disease.

Glutamate Neurotoxicity and Destruction of the Blood-Brain Barrier: Key Pathways for the Development of Neuropsychiatric Consequences of TBI and Their Potential Treatment Strategies.

Traumatic brain injury (TBI) is associated with significant cognitive and psychiatric conditions. Neuropsychiatric symptoms can persist for years following brain injury, causing major disruptions in patients' lives. In this review, we examine the role of glutamate as an aftereffect of TBI that contributes to the development of neuropsychiatric conditions. We hypothesize that TBI causes long-term blood-brain barrier (BBB) dysfunction lasting many years and even decades. We propose that dysfunction in the BBB is the central factor that modulates increased glutamate after TBI and ultimately leads to neurodegenerative processes and subsequent manifestation of neuropsychiatric conditions. Here, we have identified factors that determine the upper and lower levels of glutamate concentration in the brain after TBI. Furthermore, we consider treatments of disruptions to BBB integrity, including repairing the BBB and controlling excess glutamate, as potential therapeutic modalities for the treatment of acute and chronic neuropsychiatric conditions and symptoms. By specifically focusing on the BBB, we hypothesize that restoring BBB integrity will alleviate neurotoxicity and related neurological sequelae.

Pathophysiology and Current Drug Treatments for Post-Stroke Depression: A Review.

Post-stroke depression (PSD) is a biopsychosocial disorder that affects individuals who have suffered a stroke at any point. PSD has a 20 to 60 percent reported prevalence among stroke survivors. Its effects are usually adverse, can lead to disability, and may increase mortality if not managed or treated early. PSD is linked to several other medical conditions, including anxiety, hyper-locomotor activity, and poor functional recovery. Despite significant awareness of its adverse impacts, understanding the pathogenesis of PSD has proved challenging. The exact pathophysiology of PSD is unknown, yet its complexity has been definitively shown, involving mechanisms such as dysfunction of monoamine, the glutamatergic systems, the gut-brain axis, and neuroinflammation. The current effectiveness of PSD treatment is about 30-40 percent of all cases. In this review, we examined different pathophysiological mechanisms and current pharmacological and non-pharmacological approaches for the treatment of PSD.

Atrial Fibrillation and Mortality in the Oldest Old after Surgery for Hip Fractures.

INTRODUCTION: One-year mortality following hip fractures increases steeply with age, from 2% in the 60- to 69-year-old population up to 28% in the oldest old (older than 90 years). Of the various factors that contribute to hip fractures, atrial fibrillation (AF) is an independent risk factor at any age. OBJECTIVE: The objective of this study was to assess the association of AF with mortality among the oldest old with hip fractures. METHOD: This is a retrospective cohort study of 701 persons above age 90 years who underwent orthopedic repair for a hip fracture during 2000-2018. Of them, 218 (31%) had AF at hospital admission. The primary outcome was survival following surgery. We compared patient characteristics and 30-day, 180-day, 1-year, and 3-year survival between patients with and without AF. RESULTS: The adjusted odds ratio for 30-day postoperative mortality for those with AF versus without AF group was 1.03 (95% confidence interval [CI] 0.63-1.66). Survival estimates were higher among those without AF than with AF at 180 days postoperative: 0.85 (95% CI 0.82-0.89) versus 0.68 (95% CI 0.61-0.74), p < 0.001; at 1 year postoperative: 0.68 (95% CI 0.63-0.72) versus 0.48 (95% CI 0.42-0.55), p < 0.001; and at 3 years postoperative: 0.47 (95% CI 0.42-0.52) versus 0.28 (95% CI 0.27-0.34), p < 0.001. CONCLUSIONS: Among individuals aged >90 years, operated for hip fractures, mortality was similar for those with and without AF at 30 days postoperative. However, the survival curves diverged sharply after 180 days. Our findings suggest that AF is not an immediate surgical risk factor, but rather confers increased long-term risk in this population.

Chronic pain in parturients with an accidental dural puncture: A case-controlled prospective observational study.

BACKGROUND: We set out to examine incidence of chronic headache and back pain in women with PDPH after accidental dural puncture during labor. METHODS: Chronic headache, backache, and disability were assessed 18-24 months postpartum. Women with PDPH treated with epidural blood patch (PDPH-EBP) were identified and matched with women who had a PDPH without epidural blood patch (PDPH-no EBP), with women with uncomplicated epidural analgesia and with women without epidural analgesia. Our primary outcome was incidence of chronic headache and backache. Secondary outcome was the effect of epidural blood patch on chronic pain development. We used Chi-square or Fisher's exact test to calculate odds ratios. RESULTS: There was no statistically significant difference in demographic characteristics between groups. In the no epidural group, no women reported chronic headache and 2/116 (1.7%) reported chronic backache. In the uncomplicated epidural group, no women reported chronic headache and 7/116 (6.0%) reported chronic backache. In the PDPH-no EBP group, 9/56 (16.1%) women reported chronic headache and 10/56 (17.9%) reported chronic backache. In the PDPH-EBP group, 12/59 (20.3%) had chronic headache and 14/59 (23.7%) had chronic backache. No women in the no epidural or uncomplicated epidural group reported disability (chronic pain score of 3 or 4). High disability was reported by 8.9% of women in the PDPH-no EBP group and by 8.4% in the PDPH-EBP group. CONCLUSION: Women with PDPH had a high incidence of chronic headache, back pain, and disability. We did not find a statistically significant difference in chronic pain development between conservatively treated and EBP-treated patients.

Human Factor Considerations in Using Personal Protective Equipment in the COVID-19 Pandemic Context: Binational Survey Study.

BACKGROUND: Full level 1 personal protective equipment (PPE) is used in various domains and contexts. Prior research has shown influences of such equipment on performance, comfort, and contamination levels. The coronavirus disease (COVID-19) pandemic forced a pervasive requirement of PPE, with little preparation, rushed deployment, inadequate time for training, and massive use by personnel who are inexperienced or not qualified in its effective use. OBJECTIVE: This study aims to examine the key human factors (physical and ergonomic, perceptual and cognitive) that influence the use of level 1 PPE when attending to patients with suspected or confirmed COVID-19. METHODS: The research approach consisted of a short survey disseminated to health care professionals in two countries, Israel and Portugal, with similar demographics and health care systems. The survey included 10 items with a 5-point Likert scale regarding the key human factors involved in level 1 PPE, as identified in prior research. RESULTS: A total of 722 respondents from Israel and 301 respondents from Portugal were included in the analysis. All the respondents reported using level 1 PPE with patients with COVID-19 in the range of several hours daily to several hours weekly. The Cronbach α was .73 for Israel and .75 for Portugal. Responses showed high levels of difficulty, with medians of 4 for items related to discomfort (n=539/688, 78% in Israel; n=328/377, 87% in Portugal), hearing (n=236/370, 64% in Portugal; n=321/642, 50% in Israel), seeing (n=697/763, 89% in Israel; n=317/376, 84% in Portugal), and doffing (n=290/374, 77% in Portugal; n=315/713, 44% in Israel). A factor analysis showed a set of strongly related variables consisting of hearing, understanding speech, and understanding the situation. This suggests that degradation in communication was strongly associated with degradation in situational awareness. A subsequent mediation analysis showed a direct effect of PPE discomfort on situational awareness (P<.001); this was also influenced (mediated) by difficulties in communicating, namely in hearing and understanding speech. CONCLUSIONS: In 2020, the COVID-19 pandemic is paving the way for updating PPE design. The use of already deployed technology affords ample opportunities to improve, adapt, and overcome caveats. The findings here suggest that the use of level 1 PPE with patients with COVID-19 has perceptual and cognitive effects, in addition to physical and ergonomic influences. Efforts should be taken to mitigate the harmful effects of such influences, both regarding the performance of medical actions and the risk of contamination to health care workers. Such efforts involve the design of PPE; the introduction of technologies to enhance vision, hearing, and communicating during the use of PPE; and training staff in using the equipment and in effective communication and teamwork protocols.

Estimations of a degree of steroid induced leukocytosis in patients with acute infections.

BACKGROUND: Glucocorticosteroids (GCS) are known to cause the hematologic effect of leukocytosis and neutrophilia. Leukocytosis is a key parameter in establishing the diagnosis of sepsis and in the estimation of its severity. OBJECTIVE: To quantify the effect of chronic or acute GCS treatment on the level of leukocytosis in patients with acute infectious process. METHODS: We conducted a retrospective cohort study of patients with an acute infection hospitalized in tertiary medical center between the years 2003-2014. Patients were classified into three categories: chronic GCS treatment, acute GCS treatment, no GCS treatment. The primary outcome was the maximal WBC count within the first 24h from admission. RESULTS: We identified 5468 patients with acute infection: 333 of them with chronic GCS treatment, 213 with acute GCS treatment and 4922 with no GCS treatment. The overall maximal leukocytes count was higher in GCS therapy groups: 15.4±8.3×109/L for the acute GCS treatment, 14.9±7.4×109/L for chronic GCS treatment and 12.9±6.4×109/L for the no GCS group (P<0.001). CONCLUSION: In patients with acute infections chronically treated with GCS, an increase in the WBC is at average of 5×109/L. These data must be taken into consideration while using the level of leukocytosis as a parameter in the diagnosis of the infectious process.

Single-Operator Ultrasound-Guided Central Venous Catheter Insertion Verifies Proper Tip Placement.

OBJECTIVES: To evaluate whether a single-operator ultrasound-guided, right-sided, central venous catheter insertion verifies proper placement and shortens time to catheter utilization. DESIGN: Prospective observational study with historical controls. SETTING: Adult ICUs. PATIENTS: Sixty-four consecutive patients undergoing ultrasound-assisted right-sided central venous catheterization compared with 92 serial historic controls who had unassisted central catheter insertion at the same sites. INTERVENTIONS: Subcostal transthoracic echocardiography during catheter insertion. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the correct placement of the catheter tip determined by postprocedural chest radiography. The subclavian site was used in 41 patients (64%) (inserted without ultrasound guidance) in the ultrasound-assisted group and 62 (67%) in the control group, whereas the jugular vein was used in the remaining patients. The tip was accurately positioned in 59 of 68 patients (86.7%) in the ultrasound-assisted group compared with 51 of 94 (54.8%) in the control group (p < 0.001). The median time from end of the procedure to catheter utilization after chest radiography approval was 2.4 hours. CONCLUSIONS: A single-operator ultrasound-guided central venous catheter insertion is effective in verifying proper tip placement and shortens time to catheter utilization.

Multidrug Resistance Acinetobacter Bacteremia Secondary to Ventilator-Associated Pneumonia: Risk Factors and Outcome.

PURPOSE: Acinetobacter baumannii is a multidrug resistant (MDR), gram-negative bacterium commonly implicated in ventilator-associated pneumonia (VAP) in critically ill patients. Patients in the intensive care unit (ICU) with VAP often subsequently develop A baumannii bacteremia, which may significantly worsen outcomes. MATERIALS AND METHODS: In this study, we retrospectively reviewed the clinical and laboratory records of 129 ICU patients spanning 6 years with MDR A baumannii VAP; 46 (35%) of these patients had concomitant MDR A baumannii bacteremia. RESULTS: The ICU mortality rate was higher in patients with VAP having A baumannii bacteremia compared to nonbacteremic patients (32.4% vs 9.6% respectively, P < .005). Age >65 years, an Acute Physiology and Chronic Health Evaluation II (APACHE-II) score higher than 20, a Sequential Organ Failure Assessment (SOFA) score higher than 7 on the day of bacteremia, and the presence of comorbid disease (chronic obstructive pulmonary disease [COPD] and chronic renal failure) were found to be independent risk factors for in-hospital mortality in this population. Multidrug resistant A baumannii was not an independent risk factor for mortality. CONCLUSION: Although the presence of comorbid diseases (COPD and chronic renal failure) and severity of disease (APACHE > 20 and SOFA >7) were found to be independent risk factors for ICU mortality, MDR A baumannii bacteremia was not an independent risk factor for mortality in our critically ill population.

Validation of a Cross-Infection Control Program in an Understaffed Intensive Care Unit.

BACKGROUND: The authors describe a multifaceted cross-infection control program that was implemented to contain an epidemic of multidrug-resistant microorganisms (MRO) (carbapenem resistant Pseudomonas aeruginosa and Acinetobacter baumannii; extended spectrum ß-lactamase producing Klebsiella pneumoniae, Escherichia coli, Enterobacter Cloacae, and Proteus mirabilis; and methicillin-resistant Staphylococcus aureus and Candida species). OBJECTIVES: To assess the effect of a control program on the incidence of cross-infection with MRO. METHODS: Clinical criteria triaged patients into a high-risk wing (HRW) or a low-risk wing (LRW). Strict infection control measures were enforced; violations led to group discussions (not recorded). Frequent cultures were obtained, and use of antibiotics was limited. Each quarter, the incidence of MRO isolation was reported to all staff members. RESULTS: Over a 6 year period, 1028 of 3113 patients were placed in the HRW. The incidence of MRO isolation within 48 hours of admission was 8.7% (HRW) vs. 1.91% (LRW) (P < 0.001). Acquired MRO infection density was 30.4 (HRW) vs. 15.6 (LRW) (P < 0.009). After the second year, the incidence of group discussions dropped from once or twice a month to once or twice a year. CONCLUSIONS: These measures contained epidemics. Clinical criteria successfully triaged HRW from LRW patients and reduced cross-infection between the medical center wings. The quarterly reports of culture data were associated with improved staff compliance. MRO epidemic control with limited resources is feasible.

Positive fluid balance as a major predictor of clinical outcome of patients with sepsis/septic shock after ICU discharge.

INTRODUCTION: Sepsis and septic shock continue to be syndromes that carry a high mortality rate worldwide. Early aggressive fluid and vasopressor support have resulted in significant improvement in patient outcomes. The prognostic clinical significance of a positive fluid balance in septic intensive care unit (ICU) patients remains undetermined. METHODS: We collected data from 297 septic patients hospitalized in our general and medical ICUs at Soroka Medical Center between January 2005 and June 2011 and divided the 4 study groups into the following 4 fluid balances: group 1, patients with fluid balance at discharge from ICU (FBD) less than 10 L; group 2, patients with an FBD of 10 to 20 L; group 3, patients with an FBD of 20 to 30 L; and group 4, patients with FBD in excess of 30 L. RESULTS: The ICU and in-hospital mortality rate was also significantly higher in groups 2 to 4 as compared with group 1 (P < .001 for both ICU and in-hospital mortality). The positive cumulative FBD was found to be an independent predictor of ICU mortality (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02-1.06; P < .001; Table 3) and in-hospital mortality (OR, 1.06; 95% CI, 1.03-1.08; P < .001; Table 5) and also to constitute a risk factor for new organ system dysfunction at hospital discharge (OR, 1.01; 95% CI, 1.01-1.013; P < .001; Table 6) in critically ill patients with severe sepsis/septic shock. CONCLUSIONS: Although it is a monocentric retrospective study, we suggest that positive cumulative fluid balance is one of the major factors that can predict the clinical outcome of critically ill patients during their ICU stay and after their discharge from the ICU.

Comparison of the effectiveness of high flow nasal oxygen cannula vs. standard non-rebreather oxygen face mask in post-extubation intensive care unit patients.

BACKGROUND: Optimal oxygen supply is the cornerstone of the management of critically ill patients after extubation, especially in patients at high risk for extubation failure. In recent years, high flow oxygen system devices have offered an appropriate alternative to standard oxygen therapy devices such as conventional face masks and nasal prongs. OBJECTIVES: To assess the clinical effects of high flow nasal cannula (HFNC) compared with standard oxygen face masks in Intensive Care Unit (ICU) patients after extubation. METHODS: We retrospectively analyzed 67 consecutive ventilated critical care patients in the ICU over a period of 1 year. The patients were allocated to two treatment groups: HFNC (34 patients, group 1) and non-rebreathing oxygen face mask (NRB) (33 patients, group 2). Vital respiratory and hemodynamic parameters were assessed prior to extubation and 6 hours after extubation. The primary clinical outcomes measured were improvement in oxygenation, ventilation-free days, re-intubation, ICU length of stay, and mortality. RESULTS: The two groups demonstrated similar hemodynamic patterns before and after extubation. The respiratory rate was slightly elevated in both groups after extubation with no differences observed between groups. There were no statistically significant clinical differences in PaCO2. However, the use of HFNC resulted in improved PaO2/FiO2 post-extubation (P < 0.05). There were more ventilator-free days in the HFNC group (P< 0.05) and fewer patients required reintubation (1 vs. 6). There were no differences in ICU length of stay or mortality. CONCLUSION: This study demonstrated better oxygenation for patients treated with HFNC compared with NRB after extubation. HFNC may be more effective than standard oxygen supply devices for oxygenation in the post-extubation period.

The Impact of Information Relevancy and Interactivity on Intensivists' Trust in a Machine Learning-Based Bacteremia Prediction System: Simulation Study.

Background: The exponential growth in computing power and the increasing digitization of information have substantially advanced the machine learning (ML) research field. However, ML algorithms are often considered "black boxes," and this fosters distrust. In medical domains, in which mistakes can result in fatal outcomes, practitioners may be especially reluctant to trust ML algorithms. Objective: The aim of this study is to explore the effect of user-interface design features on intensivists' trust in an ML-based clinical decision support system. Methods: A total of 47 physicians from critical care specialties were presented with 3 patient cases of bacteremia in the setting of an ML-based simulation system. Three conditions of the simulation were tested according to combinations of information relevancy and interactivity. Participants' trust in the system was assessed by their agreement with the system's prediction and a postexperiment questionnaire. Linear regression models were applied to measure the effects. Results: Participants' agreement with the system's prediction did not differ according to the experimental conditions. However, in the postexperiment questionnaire, higher information relevancy ratings and interactivity ratings were associated with higher perceived trust in the system (P<.001 for both). The explicit visual presentation of the features of the ML algorithm on the user interface resulted in lower trust among the participants (P=.05). Conclusions: Information relevancy and interactivity features should be considered in the design of the user interface of ML-based clinical decision support systems to enhance intensivists' trust. This study sheds light on the connection between information relevancy, interactivity, and trust in human-ML interaction, specifically in the intensive care unit environment.