Background: The use of resuscitative endovascular balloon occlusion of the aorta (REBOA) for hemorrhagic shock in the torso has become increasingly common as a bridge to definitive hemostasis. Hydrogen molecules, distributed throughout the bloodstream, alleviate ischemic injury but cannot reach ischemic organs during REBOA use. This study investigates whether intra-aortic irrigation with hydrogen-dissolved saline under REBOA use delivers hydrogen to the intestine in a swine hemorrhagic shock model. Methods: We induced volume-regulated hemorrhagic shock in a 40 kg female swine. Following this, hydrogen-dissolved saline irrigation was initiated through an intra-aortic catheter positioned distal to the REBOA balloon. Hydrogen concentration in the portal vein was determined in four models: controlled hemorrhagic shock with full REBOA inflation during the standard occlusion time, uncontrolled hemorrhagic shock with liver injury and full REBOA inflation during the extended occlusion time, uncontrolled hemorrhagic shock with liver injury and partial REBOA inflation during the extended occlusion time, and as the control model, controlled hemorrhagic shock with full REBOA inflation during the standard occlusion time with normal saline irrigation without hydrogen. Results: Hydrogen concentration in the portal vein was found to be 0.224 mg/L (13.998%) in the controlled hemorrhagic shock model with full REBOA inflation, 0.049 mg/L (3.063%) in the uncontrolled hemorrhagic shock model with liver injury and full REBOA inflation, 0.018 mg/L (1.125%) in the uncontrolled hemorrhagic shock model with liver injury and partial REBOA inflation, and 0.002 mg/L (0.015%) in the control model. These results demonstrate the presence of hydrogen in the portal vein under different REBOA applications. Conclusions: Increased hydrogen concentration in the portal vein indicated that hydrogen was delivered to the intestine. These findings suggest an approach for drug administration during REBOA use. However, further investigations are required to establish its application in clinical settings.

Abstract Background The role of lactate level in selecting the timing of definitive surgery for isolated extremity fracture remains unclear. Therefore, we aimed to elucidate the use of preoperative lactate level for predicting early postoperative complications. Methods This was a single-center retrospective observational study of patients with isolated extremity fracture who underwent orthopedic surgery. Patients who underwent lactate level assessment within 24 h prior to surgery were included. The incidence of early postoperative complications was compared between patients with a preoperative lactate level of ≥ 2 and < 2 mmol/L. Moreover, subgroup analyses were performed based on the time from hospital arrival to surgery and fracture type. Results In total, 187 patients were included in the study. The incidence of postoperative complications was significantly higher in patients with a preoperative lactate level of ≥ 2 mmol/L than those with a preoperative lactate level of < 2 mmol/L. This result did not change after adjusting for age and severity. Further, a high preoperative lactate level was associated with a greater incidence of postoperative complications in patients who underwent definitive surgery within 6 h after arrival. Conclusion A preoperative lactate level of ≥ 2 mmol/L was associated with a greater incidence of early postoperative complications in isolated extremity fractures. Nevertheless, this correlation was only observed among patients who underwent definitive fixation within 6 h after hospital arrival.

Introduction: Early appropriate care (EAC) is widely accepted as a safe strategy to perform early definitive fracture fixation, and good clinical outcomes have been reported in selected, multiply injured patients, although the optimal candidate for early definitive fixation (EDF) has not been validated. The aim of this study was to identify simple clinical parameters to help select patients who could undergo EDF. Methods: Patients with extremity injuries who underwent open reduction and internal fixation were retrospectively identified, using data from the Japan Trauma Data Bank (JTDB). Age, vital signs on hospital presentation, and the injury severity score (ISS) were examined by transforming these variables to binary categories. Patients were divided into categories based on these variables, and in-hospital mortality was compared between patients treated with EDF (EDF group) and those treated without EDF (non-EDF group) in each category. Results: Of the 12,735 patients who were eligible for the analyses, 3706 (29.1 %) were managed with EDF. In-hospital mortality was significantly higher in the EDF group than in the non-EDF group among patients with a low Glasgow Coma Scale (GCS) score (<13), low systolic blood pressure (sBP) (<90 mmHg), and ISS >= 15, whereas in-hospital mortality was comparable between the EDF and non-EDF groups among patients with GCS scores >= 13, sBP >= 90 mmHg, and ISS <15. Discussion: In this large nationwide database of trauma patients, EDF was performed without affecting mortality in patients with GCS scores >= 13 and sBP >= 90 mmHg on hospital presentation, as well as ISS <15. These parameters might be useful as screening tools to select the candidates who could be treated with EDF safely.

Background: Recently, the resuscitative endovascular balloon occlusion of the aorta (REBOA) has become widespread in hemorrhagic shock (HS). It temporarily increases the proximal blood pressure (pBP); but sacrifices the distal blood flow to the visceral organs, causing ischemic injury. We previously reported that hydrogen (H 2 ) gas inhalation mitigated ischemic injury and improved survival in rats with HS; however, during REBOA use, the H 2 gas was not delivered to the ischemic organs as it is distributed via the bloodstream. Therefore, we hypothesized that intra-aortic irrigation of H 2 -containing solution into the downstream of REBOA would mitigate ischemic injury. Methods: Herein, a swine liver injury with volume-regulated HS model was used. The female swine (around 40 kg, n = 16) were divided into two groups; a H 2 -containing solution irrigation (H 2 group) and saline irrigation (C group). After HS induction (20% of estimated total blood volume), the liver injury was initiated (20% of total liver volume). The REBOA was inflated during predefined time (60 min and 90 min) and intra-aortic irrigation to downstream of REBOA was started. The hemodynamic parameters, blood samples, and pathological changes were evaluated. Results: The elevation in lactate, interleukin 6, and syndecan levels were significantly suppressed over time in the H 2 group than in C group (p < 0.05). The pBP tended to decrease during REBOA in the C group; however, it remained higher in H 2 group (p < 0.05). Pathologically, the ischemic changes, such as liver sinusoidal enlargement and intestinal villi flattening and inflammatory infiltration were identified in the C group but not in H 2 group. Conclusion: The REBOA with downstream intra-aortic irrigation using H 2 -containing solution for liver injury with HS stabilizes hemodynamics, suppresses cellular injury, and mitigates organ damages. These results in large animals can be immediately applied to clinical use in humans.

Background: While various strategies of fracture fixation for trauma patients have been discussed, optimal candidates remain unclear for early definitive fixation. The aim of this study was to integrate several clinical parameters into a scoring system and determine a cut-off value for safe early definitive surgery for extremity fractures. Methods: We retrospectively identified patients with fracture in an extremity in Japanese Trauma Data Bank from 2004 to 2019. We included adult patients who underwent open reduction and internal fixation for extremity injury before any other surgical intervention and excluded those who arrived with cardiac arrest. Several clinical parameters, such as age, vital signs, abbreviated injury scale (AIS) in the chest, and injury severity score (ISS), were examined with multivariate logistic regression models to predict in-hospital mortality, and then integrated into a scoring system based on each odds ratio. To determine a cut-off value of the scoring system for safe early definitive surgery, in-hospital mortality and/or postoperative complications were compared between patients who underwent definitive fixation within 24 h of injury and patients who did not in subgroups based on the scores. Results: Of 50,631 patients eligible for this study, 16,119 (31.8%) underwent early definitive fixation. A 0 -15 scoring system with parameters including age >70 years, GCS <8, systolic blood pressure <90 mmHg, AIS in the chest & GE;3, ISS & GE;20, and transfusion requirement within 24 h of arrival was developed. At scores & GE;10, early definitive fixation was found to be significantly associated with high inhospital mortality, and at scores <10, in-hospital mortality was comparable between the two groups. Conclusions: We integrated clinical parameters into the scoring system with a scale of 0-15 and determined that a score of 10 is the cut-off score. We determined that patients with a score <10 can safely undergo early definitive fixation. & COPY; 2021 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Background: The use of resuscitative endovascular balloon occlusion of the aorta (REBOA) for hemorrhagic shock (HS) has grown in popularity. However, REBOA has a risk of complications related to blocking the blood flow downstream to the visceral organs. Several drugs have been reported so far to mitigate ischemia, including hydrogen gas (H 2 ); however, they could not reach the downstream of REBOA as they are distributed through the bloodstream. This study aimed to develop a system to deliver drugs to the ischemic organs where REBOA blocks the bloodstream. Methods: Herein, a female 40-kg swine volume-regulated HS model was used. In addition to the REBOA in zone 1, a catheter was inserted for drug delivery retrograde into the right femoral artery. The top tip of the catheter was positioned distal to the REBOA balloon. After HS induction (20% of the total blood volume), drug delivery capability was evaluated in three REBOA use patterns, such as controlled HS in normal time of full inflation , uncontrolled HS with liver injury in extended time of full inflation, and partial inflation. Simultaneously with the REBOA inflation, the intra-aortic irrigation of a drug-containing solution, H 2 -dissolved saline, was initiated. Results: The occlusion by the REBOA was achieved in all cases after shock induction (approximately 40 mmHg). In all patterns, the concentration of H 2 in the portal vein, which represents the concentration of outflow from the intestine and inflow to the liver, increased immediately after the irrigation. A full inflation setting required 30 mL/min of irrigation speed to obtain the minimum effective concentration of H 2 (1%), whereas a partial inflation setting required 2 mL/min. Conclusion: A drug delivery system combined with the REBOA was developed, which enabled the drugs to be administered downstream of REBOA. The newly developed system can potentially overcome the major limitations of REBOA.

Introduction: While various strategies of fracture fixation in trauma victims have been discussed, the effect of damage control orthopedics (DCO) on significant clinical outcome is inconclusive. We examined the mortality of patients managed with DCO, comparing those without DCO, using a nationwide trauma database. Patients and Methods: We retrospectively identified patients with extremity injury, defined as patients with an Abbreviated Injury Scale (AIS) of >= 2 in an upper or lower extremity, in the database that included more than 200 major hospitals from 2004 to 2016. We included those who were age >= 15 years and underwent ORIF. Patients with missing survival data or invalid vital signs at hospital arrival were excluded. Patient data were divided into DCO or non-DCO groups, and propensity scores were developed to estimate the probability of being assigned to the DCO group, using multivariate logistic regression analyses adjusted for known survival predictors, such as age, vital signs at arrival, Abbreviated Injury Scale in extremity, ISS, presence of vascular injury, surgical procedure before fracture treatment, and transfusion requirement. The primary outcome, in-hospital mortality, was compared between the two groups after propensity score matching. Survival analyses were performed, and hazard ratio was adjusted according to age, systolic blood pressure on arrival, and Injury Severity Score. Results: Of the 19,319 patients included in this study, 4407 (22.8%) underwent DCO. After the propensity score matching, 3858 pairs were selected. In-hospital mortality was significantly lower among patients in the DCO than those in the non-DCO groups (40 [1.0%] vs. 66 [1.7%]; odds ratio = 0.60; 95% confidence interval [CI] = 0.41-0.89; P = 0.01). Survival analyses showed that DCO was independently associated with decreased mortality in patients with extremity injury (adjusted hazard ratio = 0.30; 95% CI = 0.20-0.46; P < 0.01). Conclusions: DCO was associated with decreased in-hospital mortality in patients with major fractures. Further clinical study on DCO by selecting patient population should be considered eventually to develop an appropriate strategy for major fractures. (C) 2019 Elsevier Ltd. All rights reserved.