Antibiotics in patients with severe burn injury-A modifiable variable in hypernatremia etiology.

INTRODUCTION: Hypernatremia is a common problem among patients with severe burn injuries and seems to be associated with an unfavorable clinical outcome. The current study was designed to evaluate the impact of antibiotics with a high proportion of sodium on this phenomenon. METHODS: All admissions to our burn center from 01/2017 till 06/2023 were retrospectively screened. All patients aged >18 years which suffered from at least 20 % total body surface burned area (TBSA) 2nd degree burn injuries or more than 10 % TBSA when including areas of 3rd degree burn injuries were included. The course of the serum Na-level was analyzed from two days before till two days after the start of the antibiotic treatment. Ampicillin/sulbactam, cefazoline and piperacillin/tazobactam were classified as high-dose sodium antibiotics (HPS), meropenem and vancomycin as low-dose sodium antibiotics (LPS). RESULTS: 120 patients met the inclusion criteria. A significant increase of the serum Na was detectable in the HPS group on day 1 and 2 after initiating the antibiotic treatment (n = 64, day 1: 2,1 (SD 4,18) mmol/l, p < 0,001; day 2: 2,44 (SD 5,26) mmol/l, p < 0,001) while no significant changes were detectable in the LPS group (n = 21, day 1: 0,18 (SD 7,45) mmol/l, p = 0,91; day 2: -0,27 (SD 7,44) mmol/l, p = 0,87). This effect was further aggravated when analyzing only the HPS patients with a TBSA ≥30 % (n = 33; day 1: 2,93 (SD 4,68) mmol/l, p = 0,002; day 2: 3,41 (SD 5,9) mmol/l, p = 0,003). CONCLUSION: The amount of sodium in antibiotics seems to have a relevant impact on the serum Na during the early stages of severe burn injury. Therefore, this aspect should be taken into account when searching for the most appropriate antibiotic treatment for patients with severe burn injury, especially when being at acute risk for a clinical relevant hypernatremia.

Semaphorin 7A coordinates Neutrophil response during pulmonary inflammation and sepsis.

RATIONALE: Pulmonary defense mechanisms are critical for host integrity during pneumonia and sepsis. This defense is fundamentally dependent on the activation of neutrophils during the innate immune response. Recent work has shown that Semaphorin 7A (Sema7A) holds significant impact on platelet function, yet its role on neutrophil function within the lung is not well understood. OBJECTIVE: To identify the role of Sema7A during pulmonary inflammation and sepsis. MEASUREMENTS AND MAIN RESULTS: In ARDS patients we were able to show a correlation between Sema7A and oxygenation levels. During subsequent workup we found that Sema7A binds to the neutrophil PlexinC1 receptor, increasing integrins and L-selectin on neutrophils. Sema7A prompted neutrophil chemotaxis in-vitro and the formation of platelet-neutrophil complexes in-vivo. We also observed altered adhesion and transmigration of neutrophils in Sema7A-/- animals in the lung during pulmonary inflammation. This effect resulted in increased number of neutrophils in the interstitial space of Sema7A-/- animals but reduced numbers of neutrophils in the alveolar space during pulmonary sepsis. This finding was associated with significantly worse outcome of Sema7A-/- animals in a model of pulmonary sepsis. CONCLUSIONS: Sema7A has an immunomodulatory effect in the lung affecting pulmonary sepsis and ARDS. This effect influences the response of neutrophils to external aggression and might influence patient outcome.

Severe Burn Injuries - The Day the Sodium Starts Rising.

BACKGROUND/AIM: The current study was designed to evaluate the etiologies of hypernatremic episodes in patients with severe burn injuries in comparison to critically ill non-burn patients. PATIENTS AND METHODS: The retrospective data acquisition was limited to the first 14 days and to patients with at least 20% total body surface area (TBSA) 2nd degree burn injuries or more than 10% TBSA when including areas of 3rd degree burn injuries. The results were compared to the results of a previously published study that analyzed the risk factors for hypernatremia in 390 non-burn intensive care unit patients. RESULTS: In total, 120 patients with a total of 50 hypernatremic episodes were included. Compared to non-burn injury patients, no significant differences were detectable except for a lower rate of hypokalemia and a higher rate of mechanical ventilation. The main trigger for hypernatremic episodes was the loss of free water, while 24% of the hypernatremic episodes seemed to be at least partly triggered by a surplus sodium influx. Patients with hypernatremic episodes had a significantly higher mortality rate. However, in none of the cases was hypernatremia the decisive cause of death. CONCLUSION: Besides the unique phenomenon of high volume internal and external volume shifts, the overall risk factors and etiologies of hypernatremia in patients with severe burn injury do not seem to significantly differ from other ICU patient collectives. Remarkably, a surplus of sodium influx and therefore a modifiable factor besides the specific burn injury volume resuscitation had an impact on the hypernatremic episodes in 24% of cases.

Development of an Anticipatory Triage-Ranking Algorithm Using Dynamic Simulation of the Expected Time Course of Patients With Trauma: Modeling and Simulation Study.

BACKGROUND: In cases of terrorism, disasters, or mass casualty incidents, far-reaching life-and-death decisions about prioritizing patients are currently made using triage algorithms that focus solely on the patient's current health status rather than their prognosis, thus leaving a fatal gap of patients who are under- or overtriaged. OBJECTIVE: The aim of this proof-of-concept study is to demonstrate a novel approach for triage that no longer classifies patients into triage categories but ranks their urgency according to the anticipated survival time without intervention. Using this approach, we aim to improve the prioritization of casualties by respecting individual injury patterns and vital signs, survival likelihoods, and the availability of rescue resources. METHODS: We designed a mathematical model that allows dynamic simulation of the time course of a patient's vital parameters, depending on individual baseline vital signs and injury severity. The 2 variables were integrated using the well-established Revised Trauma Score (RTS) and the New Injury Severity Score (NISS). An artificial patient database of unique patients with trauma (N=82,277) was then generated and used for analysis of the time course modeling and triage classification. Comparative performance analysis of different triage algorithms was performed. In addition, we applied a sophisticated, state-of-the-art clustering method using the Gower distance to visualize patient cohorts at risk for mistriage. RESULTS: The proposed triage algorithm realistically modeled the time course of a patient's life, depending on injury severity and current vital parameters. Different casualties were ranked by their anticipated time course, reflecting their priority for treatment. Regarding the identification of patients at risk for mistriage, the model outperformed the Simple Triage And Rapid Treatment's triage algorithm but also exclusive stratification by the RTS or the NISS. Multidimensional analysis separated patients with similar patterns of injuries and vital parameters into clusters with different triage classifications. In this large-scale analysis, our algorithm confirmed the previously mentioned conclusions during simulation and descriptive analysis and underlined the significance of this novel approach to triage. CONCLUSIONS: The findings of this study suggest the feasibility and relevance of our model, which is unique in terms of its ranking system, prognosis outline, and time course anticipation. The proposed triage-ranking algorithm could offer an innovative triage method with a wide range of applications in prehospital, disaster, and emergency medicine, as well as simulation and research.

Left Atrioventricular Transvalvular Pressure Gradients Derived from Intraoperative and Postoperative Echocardiograms following Atrioventricular Septal Defect Repair.

BACKGROUND: Left atrioventricular valve (LAVV) stenosis following an atrioventricular septal defect (AVSD) repair is a rare but potentially life-threatening complication. While echocardiographic quantification of diastolic transvalvular pressure gradients is paramount in the evaluation of a newly corrected valve function, it is hypothesized that these measured gradients are overestimated immediately following a cardiopulmonary bypass (CPB) due to the altered hemodynamics when compared to postoperative valve assessments using awake transthoracic echocardiography (TTE) upon recovery after surgery. METHODS: Out of the 72 patients screened for inclusion at a tertiary center, 39 patients undergoing an AVSD repair with both intraoperative transesophageal echocardiograms (TEE, performed immediately after a CPB) and an awake TTE (performed prior to hospital discharge) were retrospectively selected. The mean (MPGs) and peak pressure gradients (PPGs) were quantified using a Doppler echocardiography and other measures of interest were recorded (e.g., a non-invasive surrogate of the cardiac output and index (CI), left ventricular ejection fraction, blood pressures and airway pressures). The variables were analyzed using the paired Student's t-tests and Spearman's correlation coefficients. RESULTS: The MPGs were significantly higher in the intraoperative measurements when compared to the awake TTE (3.0 ± 1.2 vs. 2.3 ± 1.1 mmHg; p < 0.01); however, the PPGs did not significantly differ (6.6 ± 2.7 vs. 5.7 ± 2.8 mmHg; p = 0.06). Although the assessed intraoperative heart rates (HRs) were also higher (132 ± 17 vs. 114 ± 21 bpm; p < 0.001), there was no correlation found between the MPG and the HR, or any other parameter of interest, at either time-point. In a further analysis, a moderate to strong correlation was observed in the linear relationship between the CI and the MPG (r = 0.60; p < 0.001). During the in-hospital follow-up period, no patients died or required an intervention due to LAVV stenosis. CONCLUSIONS: The Doppler-based quantification of diastolic transvalvular LAVV mean pressure gradients using intraoperative transesophageal echocardiography seems to be prone to overestimation due to altered hemodynamics immediately after an AVSD repair. Thus, the current hemodynamic state should be taken into consideration during the intraoperative interpretation of these gradients.