Comparison of mannitol and hypertonic saline solution for the treatment of suspected brain herniation during prehospital management of traumatic brain injury patients.

BACKGROUND AND IMPORTANCE: Occurrence of mydriasis during the prehospital management of traumatic brain injury (TBI) may suggest severe intracranial hypertension (ICH) subsequent to brain herniation. The initiation of hyperosmolar therapy to reduce ICH and brain herniation is recommended. Whether mannitol or hypertonic saline solution (HSS) should be preferred is unknown. OBJECTIVES: The objective of this study is to assess whether HSS, compared with mannitol, is associated with improved survival in adult trauma patients with TBI and mydriasis. DESIGN/SETTING AND PARTICIPANTS: A retrospective observational cohort study using the French Traumabase national registry to compare the ICU mortality of patients receiving either HSS or mannitol. Patients aged 16 years or older with moderate to severe TBI who presented with mydriasis during prehospital management were included. OUTCOME MEASURES AND ANALYSIS: We performed propensity score matching on a priori selected variables [i.e. age, sex and initial Coma Glasgow Scale (GCS)] with a ratio of 1 : 3 to ensure comparability between the two groups. The primary outcome was ICU mortality. The secondary outcomes were regression of pupillary abnormality during prehospital management, pulsatility index and diastolic velocity on transcranial Doppler within 24 h after TBI, early ICU mortality (within 48 h), ICU and hospital length of stay. RESULTS: Of 31 579 patients recorded in the registry between 2011 and 2021, 1417 presented with prehospital mydriasis and were included: 1172 (82.7%) received mannitol and 245 (17.3%) received HSS. After propensity score matching, 720 in the mannitol group matched 240 patients in the HSS group. Median age was 41 years [interquartile ranges (IQR) 26-60], 1058 were men (73%) and median GCS was 4 (IQR 3-6). No significant difference was observed in terms of characteristics and prehospital management between the two groups. ICU mortality was lower in the HSS group (45%) than in the mannitol group (54%) after matching [odds ratio (OR) 0.68 (0.5-0.9), P  = 0.014]. No differences were identified between the groups in terms of secondary outcomes. CONCLUSION: In this propensity-matched observational study, the prehospital osmotherapy with HSS in TBI patients with prehospital mydriasis was associated with a lower ICU mortality compared to osmotherapy with mannitol.

Assessment of a Quantra-Guided Hemostatic Algorithm in High-Bleeding-Risk Cardiac Surgery.

OBJECTIVES: To assess whether a Quantra-guided hemostatic algorithm would reduce transfusion requirement and major bleeding compared with laboratory-guided testing in patients facing high-bleeding-risk cardiac surgery. DESIGN: Single-center before-and-after study. SETTING: University hospital. PARTICIPANTS: Patients facing high-bleeding-risk cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Hemostatic algorithm was based on standard laboratory testing during the control period, then on the Quantra during the Quantra period. The primary endpoint was the number of red blood cell (RBC) units transfused on day 1 after surgery. MEASUREMENTS AND MAIN RESULTS: After propensity-score matching, 66 patients were included in the Quantra group and 117 in the control group. The Quantra group received fewer RBC units on day 1 than the control group (2 [0-5] v 4 [2-6], p = 0.016, respectively). Intraoperatively, the Quantra group received fewer RBC (2 [0-3] v 3 [1-5], p = 0.005), less fresh frozen plasma (0 [0-3] v 3[2-5], p < 0.0001), and fewer platelet units (7.5 [0-10] v 8.2 [6.3-11.7], p = 0.014). The intraoperative rates of RBC, plasma, and platelet transfusion were reduced (64% v 78%, p = 0.05; 41% v 85%, p < 0.001; 55% v 82%, p = 0.001, respectively). The RBC and plasma transfusions were reduced on days 1, 2, and 7. The incidence of major bleeding on day 1 also was reduced (36% v 56%, p = 0.014). In multivariate analysis, implementation of the Quantra-guided hemostatic algorithm was associated independently with reductions in major bleeding. CONCLUSION: Implementation of a Quantra-based hemostatic algorithm was associated with a decrease in transfusion requirement and major bleeding after high-bleeding-risk cardiac surgery. Randomized trials are needed to confirm these results.

Machine learning-based prediction of emergency neurosurgery within 24 h after moderate to severe traumatic brain injury.

BACKGROUND: Rapid referral of traumatic brain injury (TBI) patients requiring emergency neurosurgery to a specialized trauma center can significantly reduce morbidity and mortality. Currently, no model has been reported to predict the need for acute neurosurgery in severe to moderate TBI patients. This study aims to evaluate the performance of Machine Learning-based models to establish to predict the need for neurosurgery procedure within 24 h after moderate to severe TBI. METHODS: Retrospective multicenter cohort study using data from a national trauma registry (Traumabase®) from November 2011 to December 2020. Inclusion criteria correspond to patients over 18 years old with moderate or severe TBI (Glasgow coma score ≤ 12) during prehospital assessment. Patients who died within the first 24 h after hospital admission and secondary transfers were excluded. The population was divided into a train set (80% of patients) and a test set (20% of patients). Several approaches were used to define the best prognostic model (linear nearest neighbor or ensemble model). The Shapley Value was used to identify the most relevant pre-hospital variables for prediction. RESULTS: 2159 patients were included in the study. 914 patients (42%) required neurosurgical intervention within 24 h. The population was predominantly male (77%), young (median age 35 years [IQR 24-52]) with severe head injury (median GCS 6 [3-9]). Based on the evaluation of the predictive model on the test set, the logistic regression model had an AUC of 0.76. The best predictive model was obtained with the CatBoost technique (AUC 0.81). According to the Shapley values method, the most predictive variables in the CatBoost were a low initial Glasgow coma score, the regression of pupillary abnormality after osmotherapy, a high blood pressure and a low heart rate. CONCLUSION: Machine learning-based models could predict the need for emergency neurosurgery within 24 h after moderate and severe head injury. Potential clinical benefits of such models as a decision-making tool deserve further assessment. The performance in real-life setting and the impact on clinical decision-making of the model requires workflow integration and prospective assessment.

Prevalence and time-course of diaphragmatic dysfunction following lung resection: A repeated ultrasonic assessment.

PURPOSE: Ultrasound (US) allows non-invasive repeated assessments of diaphragmatic excursion (DE) and thickening fraction (DTF) at the bedside, reflecting diaphragmatic dysfunction (DD). We aimed at determining the prevalence and time-course of DD following elective thoracic surgery and the association with postoperative complications. MATERIAL AND METHODS: Prospective, single-centre, observational study with consecutive patients undergoing thoracic surgery. DE/DTF were measured by two observers blinded to each other at 3 different time-points: prior to surgery, immediately after extubation and on postoperative day 3. The changes in DE/DTF of both hemi-diaphragms over time were compared according to the side (operated/non-operated) using a two-way-ANOVA. The association with postoperative complications was assessed using logistic regression. RESULTS: Fifty patients, 60% males, aged 60 ± 15 years were included. Surgical procedures included lobectomy (n = 30), wedge-resection (n = 17) or pneumonectomy (n = 3). On the operated side, we observed a decrease in DE/DTF at D0 (-0.71 ± 0.12 mm, P < 0.05; -44 ± 30%, P < 0.05) and D3 (-0.82 ± 0.19 mm, P < 0.05; -39 ± 19%, P < 0.05) with respect to preoperative and non-operated side values over the study period. Persistent DD on the operated side was associated with an increased risk of lung infection (OR: 9.0, 95% CI [1.92-65.93], P = 0.001), ICU-admission (OR: 3.9, 95% CI [1.10-15.53], P = 0.04) according to univariate analysis and a prolonged length in hospital (OR: 1.3, 95% CI [1.1-1.7], P = 0.016) according to multivariate analysis. CONCLUSIONS: Thoracic surgery generates DD mainly observed on the operated side, which persists at least up to postoperative D3 and is associated with an increase in hospital stay.

In vitro study of factors influencing the duration of antimicrobial protection of antimicrobial-impregnated external ventricular drains.

BACKGROUND: In vitro and clinical studies assessing the duration of the protective activity of antimicrobial-impregnated external ventricular drains (AI-EVDs) gave conflicting results. OBJECTIVES: To identify factors associated with decreased antimicrobial activity of AI-EVDs that were not taken into account in previous in vitro models. METHODS: We performed in vitro experiments with Bactiseal™ AI-EVDs, under different conditions. Tested parameters were chosen to mimic conditions in which AI-EVDs are used: perfusion by saline (at different flow rates) or not perfused, dwelling medium (air, saline, saline+protein, lipid) and temperature. Antimicrobial activity was assessed by measurement of inhibitory diameters of a 0.5 cm portion of an AI-EVD (cut every 2 days) placed onto agar plates covered by a standardized Staphylococcus spp. inoculum (three different isolates). MS was used to measure concentrations of rifampicin and clindamycin after 48 h of dwelling. RESULTS: In univariate analysis, most of the tested factors were associated with reduced antimicrobial activity: liquid media (as compared with ambient air), perfusion whatever the rate flow (as compared with no perfusion) and presence of protein in the media. In multivariate analysis, dwelling in media (lipid or saline) was the most constantly associated with a reduction of inhibition diameters (P < 0.01), as compared with ambient air. After 48 h of dwelling, the clindamycin concentration was higher than 100 and 450 mg/L in saline and saline+BSA, respectively. CONCLUSIONS: The medium in which an AI-EVD is dwelling plays a significant role in the duration of AI-EVD activity. These results may explain conflicting results between clinical and in vitro studies.

Clinical decision support for severe trauma patients: Machine learning based definition of a bundle of care for hemorrhagic shock and traumatic brain injury.

BACKGROUND: Deviation from guidelines is frequent in emergency situations, and this may lead to increased mortality. Probably because of time constraints, 55% is the greatest reported guidelines compliance rate in severe trauma patients. This study aimed to identify among all available recommendations a reasonable bundle of items that should be followed to optimize the outcome of hemorrhagic shocks (HSs) and severe traumatic brain injuries (TBIs). METHODS: We first estimated the compliance with French and European guidelines using the data from the French TraumaBase registry. Then, we used a machine learning procedure to reduce the number of recommendations into a minimal set of items to be followed to minimize 7-day mortality. We evaluated the bundles using an external validation cohort. RESULTS: This study included 5,924 trauma patients (1,414 HS and 4,955 TBI) between 2011 and August 2019 and studied compliance to 36 recommendation items. Overall compliance rate to recommendation items was 71.6% and 66.9% for HS and TBI, respectively. In HS, compliance was significantly associated with 7-day decreased mortality in univariate analysis but not in multivariate analysis (risk ratio [RR], 0.91; 95% confidence interval [CI], 0.90-1.17; p = 0.06). In TBI, compliance was significantly associated with decreased mortality in univariate and multivariate analysis (RR, 0.85; 95% CI, 0.75-0.92; p = 0.01). For HS, the bundle included 13 recommendation items. In the validation cohort, when this bundle was applied, patients were found to have a lower 7-day mortality rate (RR, 0.46; 95% CI, 0.27-0.63; p = 0.01). In TBI, the bundle included seven items. In the validation cohort, when this bundle was applied, patients had a lower 7-day mortality rate (RR, 0.55; 95% CI, 0.34-0.71; p = 0.02). DISCUSSION: Using a machine-learning procedure, we were able to identify a subset of recommendations that minimizes 7-day mortality following traumatic HS and TBI. These two bundles remain to be evaluated in a prospective manner. LEVEL OF EVIDENCE: Care Management, level II.

Major bleeding complications in critically ill patients with COVID-19 pneumonia.

As patients with COVID-19 pneumonia admitted to intensive care unit (ICU) have high rates of thrombosis, high doses of thromboprophylaxis have been proposed. The associated bleeding risk remains unknown. We investigated major bleeding complications in ICU COVID-19 patients and we examined their relationship with inflammation and thromboprophylaxis. Retrospective monocentric study of consecutive adult patients admitted in ICU for COVID-19 pneumonia requiring mechanical ventilation. Data collected included demographics, anticoagulation status, coagulation tests and outcomes including major bleeding and thrombotic events. Among 56 ICU COVID-19 patients, 10 (18%) patients had major bleeding and 16 (29%) thrombotic events. Major bleeding occurred later than thrombosis after ICU admission [17(14-23) days versus 9(3-11) days respectively (p = 0.005)]. Fibrinogen concentration always decreased several days [4(3-5) days] before bleeding; D-dimers followed the same trend. All bleeding patients were treated with anticoagulants and anticoagulation was overdosed for 6 (60%) patients on the day of bleeding or the day before. In the whole cohort, overdose was measured in 22 and 78% of patients receiving therapeutic anticoagulation during fibrinogen increase and decrease respectively (p < 0.05). Coagulation disorders had biphasic evolution during COVID-19: first thrombotic events during initial hyperinflammation, then bleeding events once inflammation reduced, as confirmed by fibrinogen and D-dimers decrease. Most bleeding events complicated heparin overdose, promoted by inflammation decrease, suggesting to carefully monitor heparin during COVID-19. Thromboprophylaxis may be adapted to this biphasic evolution, with initial high doses reduced to standard doses once the high thrombotic risk period ends and fibrinogen decreases, to prevent bleeding events.

Durability of antimicrobial activity of antibiotic-impregnated external ventricular drains: a prospective study.

BACKGROUND: Antibiotic-impregnated external ventricular drains (AI-EVDs) have a debated efficacy in clinical studies. OBJECTIVES: Our aim was to assess the durability of antimicrobial activity of AI-EVDs used in clinical settings. METHODS: From April 2017 to January 2018, all consecutive AI-EVDs (Bactiseal™) inserted in adult patients were prospectively included. After removal, each AI-EVD was cultured and assessed for antimicrobial activity on both internal and external sides of AI-EVDs. Catheters were each challenged with a single Staphylococcus strain [MSSA, MRSA or methicillin-resistant Staphylococcus epidermidis (MRSE)]. MS was used to measure residual concentrations of rifampicin and clindamycin. RESULTS: Sixty-five AI-EVDs were included (56 patients). Among these, 21 were challenged with MSSA, 23 with MRSA and 21 with MRSE. Five ventriculostomy-related colonizations (9%) and two ventriculostomy-related infections (4%) occurred. Staphylococcus was the main bacterium responsible for colonization (4/5). AI-EVD inhibition decreased significantly against MRSA and MRSE according to duration of catheterization (for external and internal sides, P < 0.02) and overall volume of CSF drained (P < 0.005 for both sides against MRSE, P < 0.005 for external side against MRSA), but not against MSSA. Clindamycin concentration was not correlated with duration of catheterization or CSF volume drained, but <20% of initial concentration was recovered even after 5 days of AI-EVD dwelling. Conversely, rifampicin concentration showed a rapid and significant decline correlated to duration and CSF volume (P < 0.001 and P = 0.03, respectively). CONCLUSIONS: Antimicrobial activity of AI-EVDs dropped quickly in vivo. Antimicrobial impregnation did not prevent AI-EVD colonization by susceptible strains in 9% of the cases.