Nurse-to-Nurse Familiarity and Mortality in the Critically Ill: A Multicenter Observational Study.

Rationale: Nurse-to-nurse familiarity at work should strengthen the components of teamwork and enhance its efficiency. However, its impact on patient outcomes in critical care remains poorly investigated. Objectives: To explore the role of nurse-to-nurse familiarity on inpatient deaths during ICU stay. Methods: This was a retrospective observational study in eight adult academic ICUs between January 1, 2011 and December 31, 2016. Measurements and Main Results: Nurse-to-nurse familiarity was measured across day and night 12-hour daily shifts as the mean number of previous collaborations between each nursing team member during previous shifts within the given ICU (suboptimal if <50). Primary outcome was a shift with at least one inpatient death, excluding death of patients with a decision to forego life-sustaining therapy. A multiple modified Poisson regression was computed to identify the determinants of mortality per shift, taking into account ICU, patient characteristics, patient-to-nurse and patient-to-assistant nurse ratios, nurse experience length, and workload. A total of 43,479 patients were admitted, of whom 3,311 (8%) died. The adjusted model showed a lower risk of a shift with mortality when nurse-to-nurse familiarity increased in the shift (relative risk, 0.90; 95% confidence interval per 10 shifts, 0.82-0.98; P = 0.012). Low nurse-to-nurse familiarity during the shift combined with suboptimal patient-to-nurse and patient-to-assistant nurse ratios (suboptimal if >2.5 and >4, respectively) were associated with increased risk of shift with mortality (relative risk, 1.84; 95% confidence interval, 1.15-2.96; P < 0.001). Conclusions: Shifts with low nurse-to-nurse familiarity were associated with an increased risk of patient deaths.

Influence of the embedded participant on learners' performance during high-fidelity simulation sessions in healthcare.

BACKGROUND: The embedded participant (EP) plays a key role during a full scale/high-fidelity simulation (HFS) session. He/she is expected to guide the learner towards the achievement of the educational objectives of the scenario. However, his/her influence on learners' performance stands undetermined and this effect remains briefly addressed in the literature. This study primarily aims to assess whether the EP could have an influence on the performance of the learner during a HFS scenario. The secondary aim was to establish an inventory of the EP practices in France. METHODS: This retrospective study was conducted in Lyon Claude Bernard University Health Simulation Centre (France). Anaesthesia and critical care residents in postgraduate years 1 to 5 who were scheduled for their HFS sessions during the 2016 to 2021 academic years were included. Two investigators independently evaluated the resident performance regarding both technical and non-technical skills from video recordings. In addition, a nationwide survey was sent out by email through the networks of the Francophone Healthcare Simulation Society (SoFraSimS, Société Francophone de Simulation en Santé) to collect information on EP practices in French-speaking Simulation centres. RESULTS: From a total of 344 HFS videos analysed, a cohort of 19 experienced EPs was identified. The EPs had an influence on the technical and non-technical performances of the learners. The 147 responses to the survey showed that predefined rules of EP good practice existed in only 36% of the simulation centres and 65% of respondents believed that specific EP training would be justified. CONCLUSION: The EP can exert an influence on the performance of the learners during HFS. For acting as an EP, a great variability of practices and a lack of training are reported by professionals working in simulation centres. These results suggest that more attention must be paid to EP training and attitudes during simulation, especially if summative simulations are extensively developed.

Effects of relaxing breathing paired with cardiac biofeedback on performance and relaxation during critical simulated situations: a prospective randomized controlled trial.

BACKGROUND: Active participation in high-fidelity simulation remains stressful for residents. Increased stress levels elicited during such simulation impacts performance. We tested whether relaxing breathing, paired or not with cardiac biofeedback, could lead to enhanced performance of residents during simulation. METHODS: This randomized pilot study involved the fifth-year anesthesiology and critical care residents who participated in high-fidelity at Lyon medical simulation center in 2019. Residents were randomized into three parallel interventions: relaxing breathing, relaxing breathing paired with cardiac biofeedback, and control. Each intervention was applied for five minutes immediately after the scenario briefing. The primary endpoint was the overall performance during the simulation rated by two blinded independent investigators. The secondary endpoints included component scores of overall performance and changes in psychological states. RESULTS: Thirty-four residents were included. Compared to the control group, residents in the relaxing breathing (+ 7%, 98.3% CI: 0.3 to 13.7, P = 0.013) and relaxing breathing paired with cardiac biofeedback (+ 8%, 98.3% CI: 0.82 to 14.81, P = 0.009) groups had a higher overall performance score. Following the interventions, compared to the control group, stress level was lower when participants had performed relaxing breathing alone (P = 0.029) or paired with biofeedback (P = 0.035). The internal relaxation level was higher in both the relaxing breathing alone (P = 0.016) and paired with biofeedback groups (P = 0.035). CONCLUSIONS: Performing five minutes of relaxing breathing before the scenario resulted in better overall simulation performance. These preliminary findings suggest that short breathing interventions are effective in improving performance during simulation. TRIAL REGISTRATION: The study protocol was retrospectively registered on clinicaltrials.gov ( NCT04141124 , 28/10/2019).

Effect of motor imagery and actual practice on learning professional medical skills.

BACKGROUND: The peripheral venous catheter is the most frequently used medical device in hospital care to administer intravenous treatment or to take blood samples by introducing a catheter into a vein. The aim of this study was to examine the effect of motor imagery associated with actual training on the learning of peripheral venous catheter insertion into a simulated venous system. METHOD: This was a prospective monocentre study in 3rd year medical students. Forty medical students were assigned to the experimental group (n = 20) performing both real practice and motor imagery of peripheral venous catheter insertion or to the control group (n = 20) trained through real practice only. We also recruited a reference group of 20 professional nurses defining the benchmark for a target performance. RESULTS: The experimental group learned the peripheral venous catheter insertion faster than the control group in the beginning of learning phase (p < 0.001), reaching the expected level after 4 sessions (p = .87) whereas the control group needed 5 sessions to reach the same level (p = .88). Both groups were at the same level at the end of the scheduled training. CONCLUSIONS: Therefore, motor imagery improved professional motor skills learning, and limited the time needed to reach the expected level. Motor imagery may strengthen technical medical skill learning.

Stress Management Training Improves Overall Performance during Critical Simulated Situations: A Prospective Randomized Controlled Trial.

BACKGROUND: High-fidelity simulation improves participant learning through immersive participation in a stressful situation. Stress management training might help participants to improve performance. The hypothesis of this work was that Tactics to Optimize the Potential, a stress management program, could improve resident performance during simulation. METHODS: Residents participating in high-fidelity simulation were randomized into two parallel arms (Tactics to Optimize the Potential or control) and actively participated in one scenario. Only residents from the Tactics to Optimize the Potential group received specific training a few weeks before simulation and a 5-min reactivation just before beginning the scenario. The primary endpoint was the overall performance during simulation measured as a composite score (from 0 to 100) combining a specific clinical score with two nontechnical scores (the Ottawa Global Rating Scale and the Team Emergency Assessment Measure scores) rated for each resident by four blinded independent investigators. Secondary endpoints included stress level, as assessed by the Visual Analogue Scale during simulation. RESULTS: Of the 134 residents randomized, 128 were included in the analysis. The overall performance (mean ± SD) was higher in the Tactics to Optimize the Potential group (59 ± 10) as compared with controls ([54 ± 10], difference, 5 [95% CI, 1 to 9]; P = 0.010; effect size, 0.50 [95% CI, 0.16 to 0.91]). After specific preparation, the median Visual Analogue Scale was 17% lower in the Tactics to Optimize the Potential group (52 [42 to 64]) than in the control group (63 [50 to 73]; difference, -10 [95% CI, -16 to -3]; P = 0.005; effect size, 0.44 [95% CI, 0.26 to 0.59]. CONCLUSIONS: Residents coping with simulated critical situations who have been trained with Tactics to Optimize the Potential showed better overall performance and a decrease in stress level during high-fidelity simulation. The benefits of this stress management training may be explored in actual clinical settings, where a 5-min Tactics to Optimize the Potential reactivation is feasible prior to delivering a specific intervention.

Relaxation before Debriefing during High-fidelity Simulation Improves Memory Retention of Residents at Three Months: A Prospective Randomized Controlled Study.

BACKGROUND: High-fidelity simulation is known to improve participant learning and behavioral performance. Simulation scenarios generate stress that affects memory retention and may impact future performance. The authors hypothesized that more participants would recall three or more critical key messages at three months when a relaxation break was performed before debriefing of critical event scenarios. METHODS: Each resident actively participated in one scenario and observed another. Residents were randomized in two parallel-arms. The intervention was a 5-min standardized relaxation break immediately before debriefing; controls had no break before debriefing. Five scenario-specific messages were read aloud by instructors during debriefings. Residents were asked by telephone three months later to recall the five messages from their two scenarios, and were scored for each scenario by blinded investigators. The primary endpoint was the number of residents participating actively who recalled three or more messages. Secondary endpoints included: number of residents observing who recalled three or more messages, anxiety level, and debriefing quality. RESULTS: In total, 149 residents were randomized and included. There were 52 of 73 (71%) residents participating actively who recalled three or more messages at three months in the intervention group versus 35 of 76 (46%) among controls (difference: 25% [95% CI, 10 to 40%], P = 0.004). No significant difference was found between groups for observers, anxiety or debriefing quality. CONCLUSIONS: There was an additional 25% of active participants who recalled the critical messages at three months when a relaxation break was performed before debriefing of scenarios. Benefits of relaxation to enhance learning should be considered for medical education.

Comparison of cardiac output optimization with an automated closed-loop goal-directed fluid therapy versus non standardized manual fluid administration during elective abdominal surgery: first prospective randomized controlled trial.

An intraoperative automated closed-loop system for goal-directed fluid therapy has been successfully tested in silico, in vivo and in a clinical case-control matching. This trial compared intraoperative cardiac output (CO) in patients managed with this closed-loop system versus usual practice in an academic medical center. The closed-loop system was connected to a CO monitoring system and delivered automated colloid fluid boluses. Moderate to high-risk abdominal surgical patients were randomized either to the closed-loop or the manual group. Intraoperative final CO was the primary endpoint. Secondary endpoints were intraoperative overall mean cardiac index (CI), increase from initial to final CI, intraoperative fluid volume and postoperative outcomes. From January 2014 to November 2015, 46 patients were randomized. There was a lower initial CI (2.06 vs. 2.51 l min-1 m-2, p = 0.042) in the closed-loop compared to the control group. No difference in final CO and in overall mean intraoperative CI was observed between groups. A significant relative increase from initial to final CI values was observed in the closed-loop but not the control group (+ 28.6%, p = 0.006 vs. + 1.2%, p = 0.843). No difference was found for intraoperative fluid management and postoperative outcomes between groups. There was no significant impact on the primary study endpoint, but this was found in a context of unexpected lower initial CI in the closed-loop group.Trial registry number ID-RCB/EudraCT: 2013-A00770-45. ClinicalTrials.gov Identifier NCT01950845, date of registration: 17 September 2013.

Effect of Xenon Anesthesia Compared to Sevoflurane and Total Intravenous Anesthesia for Coronary Artery Bypass Graft Surgery on Postoperative Cardiac Troponin Release: An International, Multicenter, Phase 3, Single-blinded, Randomized Noninferiority Trial.

BACKGROUND: Ischemic myocardial damage accompanying coronary artery bypass graft surgery remains a clinical challenge. We investigated whether xenon anesthesia could limit myocardial damage in coronary artery bypass graft surgery patients, as has been reported for animal ischemia models. METHODS: In 17 university hospitals in France, Germany, Italy, and The Netherlands, low-risk elective, on-pump coronary artery bypass graft surgery patients were randomized to receive xenon, sevoflurane, or propofol-based total intravenous anesthesia for anesthesia maintenance. The primary outcome was the cardiac troponin I concentration in the blood 24 h postsurgery. The noninferiority margin for the mean difference in cardiac troponin I release between the xenon and sevoflurane groups was less than 0.15 ng/ml. Secondary outcomes were the safety and feasibility of xenon anesthesia. RESULTS: The first patient included at each center received xenon anesthesia for practical reasons. For all other patients, anesthesia maintenance was randomized (intention-to-treat: n = 492; per-protocol/without major protocol deviation: n = 446). Median 24-h postoperative cardiac troponin I concentrations (ng/ml [interquartile range]) were 1.14 [0.76 to 2.10] with xenon, 1.30 [0.78 to 2.67] with sevoflurane, and 1.48 [0.94 to 2.78] with total intravenous anesthesia [per-protocol]). The mean difference in cardiac troponin I release between xenon and sevoflurane was -0.09 ng/ml (95% CI, -0.30 to 0.11; per-protocol: P = 0.02). Postoperative cardiac troponin I release was significantly less with xenon than with total intravenous anesthesia (intention-to-treat: P = 0.05; per-protocol: P = 0.02). Perioperative variables and postoperative outcomes were comparable across all groups, with no safety concerns. CONCLUSIONS: In postoperative cardiac troponin I release, xenon was noninferior to sevoflurane in low-risk, on-pump coronary artery bypass graft surgery patients. Only with xenon was cardiac troponin I release less than with total intravenous anesthesia. Xenon anesthesia appeared safe and feasible.

Stent-Retriever Thrombectomy for Acute Anterior Ischemic Stroke with Tandem Occlusion: A Systematic Review and Meta-Analysis.

OBJECTIVES: To assess the efficacy and safety profile of stent-retriever thrombectomy (SRT) in acute anterior ischemic stroke patients with tandem occlusion. MATERIALS AND METHODS: Using the MEDLINE database, we conducted a systematic review and meta-analysis of all studies that included patients with acute ischemic stroke attributable to tandem occlusion who received treatment with SRT between November 2010 and May 2015. RESULTS: The literature search identified 11 previous studies involving a total of 237 subjects out of whom 193 (81.4 %) were treated with acute stent placement for the extracranial internal carotid artery occlusion. Mean initial NIHSS score was 17, and median time from onset to recanalization was 283.5 min. Mean intravenous thrombolysis rate was 63.8 %. In the meta-analysis, the recanalization rate reached 81 % (95 % CI, 73-89). Meta-analysis of clinical outcomes showed a pooled estimate of 44 % (95 % CI, 33-55; 10 studies) for favourable outcome, 13 % (95 % CI, 8-20; 10 studies) for mortality, and 7 % (95 % CI, 2-13; eight studies) for symptomatic intracranial haemorrhage. CONCLUSION: SRT with emergency carotid stenting is associated with acceptable safety and efficacy in acute anterior stroke patients with tandem occlusion compared to natural history. However, the best modality to treat proximal stenosis is based on an individual case basis. KEY POINTS: • Stent retriever thrombectomy of tandem occlusion is efficient and safe. • Emergent carotid stenting during thrombectomy increase symptomatic intracranial haemorrhage without impact mortality. • Thrombectomy of tandem anterior circulation occlusion may be the first therapeutic option.

Patient Mortality Is Associated With Staff Resources and Workload in the ICU: A Multicenter Observational Study.

OBJECTIVE: Matching healthcare staff resources to patient needs in the ICU is a key factor for quality of care. We aimed to assess the impact of the staffing-to-patient ratio and workload on ICU mortality. DESIGN: We performed a multicenter longitudinal study using routinely collected hospital data. SETTING: Information pertaining to every patient in eight ICUs from four university hospitals from January to December 2013 was analyzed. PATIENTS: A total of 5,718 inpatient stays were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We used a shift-by-shift varying measure of the patient-to-caregiver ratio in combination with workload to establish their relationships with ICU mortality over time, excluding patients with decision to forego life-sustaining therapy. Using a multilevel Poisson regression, we quantified ICU mortality-relative risk, adjusted for patient turnover, severity, and staffing levels. The risk of death was increased by 3.5 (95% CI, 1.3-9.1) when the patient-to-nurse ratio was greater than 2.5, and it was increased by 2.0 (95% CI, 1.3-3.2) when the patient-to-physician ratio exceeded 14. The highest ratios occurred more frequently during the weekend for nurse staffing and during the night for physicians (p < 0.001). High patient turnover (adjusted relative risk, 5.6 [2.0-15.0]) and the volume of life-sustaining procedures performed by staff (adjusted relative risk, 5.9 [4.3-7.9]) were also associated with increased mortality. CONCLUSIONS: This study proposes evidence-based thresholds for patient-to-caregiver ratios, above which patient safety may be endangered in the ICU. Real-time monitoring of staffing levels and workload is feasible for adjusting caregivers' resources to patients' needs.

Cyclosporine protects the heart during aortic valve surgery.

BACKGROUND: Part of the myocardial damage occurring during cardiac surgery is a consequence of reperfusion injury. Cyclosporine, a potent inhibitor of the opening of the mitochondrial permeability transition pore, attenuates reperfusion injury in patients with acute ST-segment elevation myocardial infarction. This study investigated whether the administration of cyclosporine just before the aortic cross-unclamping would reduce myocardial injury in patients undergoing aortic valve surgery. METHODS: This study was a monocentric, prospective, randomized, single-blinded, controlled trial. Sixty-one patients, scheduled for elective aortic valve surgery, were randomly assigned (computer-generated randomization sequence) to receive either an intravenous bolus of cyclosporine (2.5 mg/kg, cyclosporine group, n = 30) or normal saline (control group, n = 31) 10 min before aortic cross-unclamping. The primary endpoint was the 72-h area under the curve for cardiac troponin I. RESULTS: Both groups were similar with respect to baseline characteristics and aortic cross-clamping duration. A significant 35% reduction of area under the curve for cardiac troponin I was observed in the cyclosporine group compared with the control group (242 ± 225 vs. 155 ± 71 arbitrary units, mean ± SD; mean difference, -86.2 ± 42.5; 95% CI, -172.3 to -0.1; P = 0.03). Cyclosporine beneficial effect remained significant after adjustment for aortic cross-clamping duration in each group (mean difference, -88 ± 34, 95% CI, -157 to -19; P = 0.01). None of the treated patients had significant side effects (odds ratio, 0.64; 95% CI, 0.16 to 2.55; P = 0.52). CONCLUSIONS: Cyclosporine administration at the time of reperfusion protects against reperfusion injury in patients undergoing aortic valve surgery. The clinical benefit of this protection requires confirmation in a larger clinical trial.

Tissue hemoglobin monitoring is unable to follow variations of arterial hemoglobin during transitions from pulsatile to constant flow in cardiac surgery.

OBJECTIVE: To test whether the variations of tissue hemoglobin concentration (∆THb) measured by the FORE-SIGHT(TM) cerebral oximeter can accurately detect changes in arterial hemoglobin concentration (∆AHb) before, during, and after cardiopulmonary bypass. DESIGN: A prospective clinical study. SETTING: Cardiac surgery operating room. PARTICIPANTS: Thirty patients scheduled for cardiac surgery. INTERVENTIONS: Tissue hemoglobin concentration (THb) was recorded continuously via 2 sensors applied on the forehead and connected to the cerebral oximeter. Arterial hemoglobin concentration (AHb) was measured in a hematology analyzer laboratory. Hemodynamic and respiratory parameters as well as epidemiologic data also were noted. Data were collected at 3 perioperative times: After induction of anesthesia, 10 minutes after cardioplegia, and at the end of the surgery. MEASUREMENTS AND MAIN RESULTS: Ninety pairs of data were collected. The coefficient of linear regression between ∆THb and ∆AHb was 0.4 (p<0.001). After exclusion of Hb variations<5%, the trending ability of THb to predict ∆AHb was 87%. However, the Bland and Altman plot graph for THb and AHb showed major limits of agreement (2.4 times the standard deviation). Central venous pressure and carbon dioxide tension were linked independently and positively with THb (p = 0.03). CONCLUSIONS: Continuous monitoring of THb cannot accurately track variations of AHb during the transition from pulsatile to continuous flow and vice versa in cardiac surgery. Local hemodynamic factors such as PaCO2 and vasodilation significantly impact THb. In this setting, THb monitoring should not be used to guide eventual blood transfusion management.

Association of Personality Traits With the Efficacy of Stress Management Interventions for Medical Students Taking Objective Structured Clinical Examinations.

PURPOSE: Personality traits are associated with psychophysiological stress, but few studies focus on medical students. This study aimed to better understand the association of personality traits with the efficacy of stress management interventions for medical students. METHOD: A randomized controlled trial was conducted with fourth-year students who took the objective structured clinical examination at Bernard University Lyon 1 in December 2021. Students were randomized in cardiac biofeedback, mindfulness, and control groups. Each intervention was implemented for 6 minutes before the examination. Physiological stress levels were collected during the intervention. Psychological stress levels were rated by students at baseline and after the intervention. Personality traits were assessed via the Big-Five Inventory. Interactions between personality traits and the efficacy of the interventions were analyzed using multivariable linear regression models. RESULTS: Four hundred eighty-one students participated. Higher baseline psychological stress levels were associated with higher neuroticism and agreeableness ( ß = 10.27 [95% confidence interval {CI}, 7.40-13.13; P < .001] and ß = 3.42 [95% CI, 0.98-5.85; P = .006], respectively) and lower openness ( ß = -4.95; 95% CI, -7.40 to -2.49; P < .001). As compared with the control intervention, both stress management interventions led to lower levels of psychological ( P < .001 for both) and physiological stress levels (biofeedback: P < .001 and mindfulness: P = .009). Biofeedback efficacy varied by extraversion score for psychological ( ß = -5.66; 95% CI, -10.83 to -0.50; P = .03) and physiological stress reduction ( ß = -0.002; 95% CI, -0.003 to -0.00004; P = .045). Mindfulness efficacy varied by agreeableness score for psychological stress reduction ( ß = -7.87; 95% CI, -13.05 to -2.68; P = .003). CONCLUSIONS: Students with a high score in extraversion may benefit more from biofeedback interventions, while students with high scores in agreeableness may benefit more from mindfulness interventions.

Candida albicans and non-Candida albicans fungemia in an institutional hospital during a decade.

Since the outcomes of patients with candidemia is poor and Candida spp. with increased resistance to antifungal therapy may be associated with these results, the emergence of these blood infections caused by non-C. albicans Candida spp. was explored prospectively over a two-year period (2009-2010). Candidemia was defined as the recovery of Candida spp. in culture from a patient's blood sample. The in vitro susceptibility of each isolate to amphotericin B, caspofungin, fluconazole and voriconazole was determined. In addition, characteristics of patients and outcomes were investigated in real-time. The Candida distribution was compared to that observed in a similar study 10 years earlier in the same hospital. A total of 182 patients with candidemia were included in the study. While C. albicans was the most frequently isolated species (n = 102), non-C. albicans Candida spp. included; C. glabrata (n = 32), C. parapsilosis (n = 21), C. tropicalis (n = 13), C. krusei (n = 8), C. kefyr (n = 3), C. lusitaniae (n = 2), C. lipolytica (n = 2), C. famata (n = 1), C. guilliermondii (n = 1), C. inconspicua (n = 1), C. dubliniensis (n = 1), C. sake (n = 1) and C. nivariensis (n = 1). In seven patients, C. albicans was associated with another Candida spp. Surprisingly, this prospective study demonstrated that regardless of the department (intensive care unit or hematological department), Candida spp. distribution was no different from that found in the 1998-2001 survey, except for C. krusei. A reduction in the proportion of C. krusei isolates was observed from 2000-2010 (P = 0.028) as a result of its decreased recovery in the hematological department.

Ability of the third-generation FloTrac/Vigileo software to track changes in cardiac output in cardiac surgery patients: a polar plot approach.

OBJECTIVE: To evaluate the ability of the third-generation (3.01) of FloTrac/Vigileo monitor (Edwards Lifesciences, Irvine, CA) to follow variations in cardiac output (∆CO) using the new polar plot approach. DESIGN: Prospective interventional study. SETTING: Single hospital university study. PARTICIPANTS: Twenty-five patients referred for cardiac surgery. INTERVENTIONS: CO was measured simultaneously by 3 to 5 bolus thermodilution (COtd measurements), using a pulmonary artery catheter and by arterial pulse contour analysis, using the FloTrac/Vigileo (COvi). Data were collected at eight time points: before incision, after sternotomy, before and after protamine sulfate infusion, at the start of sternal closure, at the end of surgery, on arrival to intensive care unit, and after a standardized volume expansion with 500 mL of hetastarch 6%. MEASUREMENTS AND MAIN RESULTS: One-hundred thirty-five pairs of CO data were collected; the mean bias of all CO measurements corrected for repeated measures was 0.2 L/min with limits of agreements of -3.3 L/min and +2.9 L/min. The percentage error was 66.5%. The polar plot analysis included 71 significant ∆CO and showed a mean polar angle of -3.4 degrees with 95% polar percentage error equivalent limits of -61 to 55; 69% of analysed data points fell within the 30-degree limits and provided a correct polar concordance rate. CONCLUSIONS: Third-generation FloTrac/Vigileo software still lacks the accuracy to reliably detect changes in cardiac output (∆CO) in cardiac surgery. Improvements to FloTrac/Vigileo CO algorithm and software still are needed in this particular setting.

Use of a Digital Cognitive Aid Improves Memorization of Military Caregivers After High-Fidelity Simulations of Combat Casualty Care.

INTRODUCTION: High-fidelity simulation is widely used in the ongoing education of caregivers. However, the complex high-stakes simulated crisis environment affects memorization. This study investigated whether participants would remember more key training messages 3 months after a simulated complex emergency situation if they had used a digital cognitive aid (CA) during the simulations. MATERIALS AND METHODS: This randomized controlled trial was performed during a combat casualty training course for military physicians and nurses. Each pair of care providers completed two scenarios randomized to be undertaken either with or without a digital CA. At the end of each debriefing, instructors gave five scenario-specific key messages aloud. Three months later, learners were asked to recall the messages from their two scenarios and were scored for each scenario. The primary endpoint was the number of key messages recalled. The secondary endpoints were the influence on the results of the profession and the scenario block and age of the leader. RESULTS: Thirty-six pairs of participants were included. Due to operational constraints, only 34 completed the study. The use of the digital CA was associated with a positive effect on memorization at 3 months (F = 82.2, P < .001), unrelated to the leader's profession, age, or the scenario block. The median of the memorization scores was 2/5 [1-3] with the digital CA and 1/5 [1-1] without it, which represents a difference of one memorized element (95% CI, 1-2; η2 = 0.39). CONCLUSIONS: The digital CA allowed learners to remember twice as many key elements 3 months after simulated training of medical care for military combat casualties. A dedicated digital CA might be an asset for better care in a combat environment and for learning and memorizing critical care procedures following complex emergency situations.

Can changes in arterial pressure be used to detect changes in cardiac output during volume expansion in the perioperative period?

BACKGROUND: Cardiac output (CO) is rarely monitored during surgery, and arterial pressure remains the only hemodynamic parameter for assessing the effects of volume expansion (VE). However, whether VE-induced changes in arterial pressure accurately reflect changes in CO has not been demonstrated. The authors studied the ability of VE-induced changes in arterial pressure and in pulse pressure variation to detect changes in CO induced by VE in the perioperative period. METHODS: The authors studied 402 patients in four centers. Hemodynamic variables were recorded before and after VE. Response to VE was defined as more than 15% increase in CO. The ability of VE-induced changes in arterial pressure to detect changes in CO was assessed using a gray zone approach. RESULTS: VE increased CO of more than 15% in 205 patients (51%). Areas under the receiver operating characteristic curves for VE-induced changes in systolic, diastolic, means, and pulse pressure ranged between 0.64 and 0.70, and sensitivity and specificity ranged between 52 and 79%. For these four arterial pressure-derived parameters, large gray zones were found, and more than 60% of the patients lay within this inconclusive zone. A VE-induced decrease in pulse pressure variation of 3% or more allowed detecting a fluid-induced increase in CO of more than 15% with a sensitivity of 90% and a specificity of 77% and a gray zone between 2.2 and 4.7% decrease in pulse pressure variation including 14% of the patients. CONCLUSION: Only changes in pulse pressure variation accurately detect VE-induced changes in CO and have a potential clinical applicability.