Resuscitation from Cardiac Arrest with Tension Gastrothorax Due to Acquired Diaphragmatic Hernia.

Tension gastrothorax is a rare cause of obstructive shock induced by a distended stomach herniating into the thorax through a diaphragmatic defect. We report the process of diagnosis and emergency treatment for tension gastrothorax during cardiopulmonary resuscitation (CPR). A 71-year-old woman with multiple surgical histories had nausea and vomiting for two days. She was transferred to our hospital with circulatory failure and loss of consciousness. She presented pulseless electric activity and received CPR immediately after arrival. The right atrium and right ventricle were collapsed in the echocardiography. A chest X-ray demonstrated a dilated intestine extending from the peritoneal cavity to the mediastinum. The nasogastric tube (NGT) drained 1000 mL of stomach content and alleviated the abdominal distension, and spontaneous circulation returned immediately after the drainage. Thoracoabdominal CT showed the stomach and the transverse colon had escaped from the peritoneal cavity to the mediastinum. We diagnosed the situation as tension gastrothorax due to an acquired diaphragmatic hernia. History of multiple surgery and multiple operative scars was the first step of the diagnostic process, and the chest X-ray during CPR was the key to the diagnosis. Tension gastrothorax can be misdiagnosed as other conditions. A chest X-ray should be preceded in non-trauma settings, unlike the setting of a tension pneumothorax in trauma patients. Gastrointestinal decompression with NGT placement could be attempted quickly to improve the hemodynamic condition.

Mid-term clinical outcomes and complications of primary total knee arthroplasty in hemodialysis patients: a retrospective comparative cohort study.

BACKGROUND: Numerous patients who receive hemodialysis (HD) undergo total knee arthroplasty (TKA) due to advanced knee joint arthritis. However, there are few studies that describe the clinical outcomes and complications of TKA in HD patients. This study investigated the mid-term results of TKA in patients undergoing HD. METHODS: This single-center retrospective study compared clinical and surgical outcomes following TKA in patients who were receiving HD with those who were not. We used propensity scores to match 21 knees of 18 patients who received HD to 706 knees of 569 patients who had not received HD, from a total of 727 knees (587 patients) that underwent primary unilateral TKA. The clinical outcomes were evaluated using the American Knee Society Score-knee (AKSS-knee) and AKSS-function scores. The primary surgical outcome measure was the number of knees with postoperative complications. RESULTS: In both the HD and non-HD groups, postoperative AKSS-knee and function scores significantly improved when compared to preoperative values. Postoperative AKSS-knee and function scores were not significantly different between the groups. The number of knees with postoperative complications was larger in the HD group than the non-HD group within the first postoperative month, 0-12 months, 12-24 months, 0-24 months, and two years after surgery. Additionally, in the HD group, more complications occurred in the first month than any subsequent month in the two years after surgery. CONCLUSIONS: TKA improves AKSS-knee and function scores equivalently for HD patients and non-HD patients. However, HD patients develop more complications after TKA, especially within the first month. Therefore, surgeons who perform TKA for HD patients should obtain informed consent after explaining the possible complications, and HD patients should be carefully observed following TKA.

Clinical course of a critically ill patient with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Although several studies have reported on the clinical and epidemiological characteristics of the patient with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), clinical course of the most severe cases requiring treatment in ICU have been insufficiently reported. A 73-year-old man traveling on a cruise ship with history of hypertension and dyslipidemia developed high fever, dyspnea and cough after 7 days of steroid treatment for sudden sensorineural hearing loss, and tested positive for SARS-CoV-2 in sputa polymerase chain reaction (PCR) examination. His respiratory function deteriorated despite treatments with lopinavir/ritonavir, oseltamivir, azithromycin and meropenem at a regional hospital. He was intubated and transferred to the ICU in the tertiary university hospital on day 10 (ICU day 1). Interferon beta-1b subcutaneous injection was initiated immediately to enhance anti-viral therapy, and favipiravir on ICU day 10 upon availability. Progression of organ dysfunctions necessitated inhalation of nitrogen oxide for respiratory dysfunction, noradrenaline for cardiovascular dysfunction and continuous renal replacement therapy for renal dysfunction. His blood samples PCR also tested positive for SARS-CoV-2, indicating viremia, concomitantly with elevated IL-6 levels. VV-ECMO was initiated after sudden exacerbation of respiratory dysfunction on ICU day 7 to maintain oxygenation. The sustained excessive inflammatory cytokines in the present case might have led to the exacerbation of the disease, requiring vigorous organ support therapies to allow for survival and recovery from the rapid progression of multiple organ dysfunctions and severe respiratory failure.

The off-hour effect among severe trauma patients: a nationwide cohort study in Japan.

PURPOSE: To assess whether there are temporal differences altering the clinical outcomes of severe trauma patients in Japan. METHODS: This was a retrospective cohort study that used recorded data from the Japan Trauma Data Bank. Severe trauma patients who had an injury severity score of greater than 16 were included. The hospital arrival time was categorized into daytime (8 a.m.-7:59 p.m.) and nighttime (8 p.m.-7:59 a.m.). The hospital arrival day of the week was categorized into business days and non-business days. The primary outcome was in-hospital mortality. RESULTS: A total of 65,136 severe trauma patients were analyzed. In-hospital mortality was 15.6% in the daytime and 14.4% in the nighttime, and 15.5%, and 14.6% on business days and non-business days, respectively. Nighttime was associated with decreased in-hospital mortality compared to daytime (odds ratio = 0.817, 95% confidence interval = 0.764-0.874) and a non-business day was not associated with in-hospital mortality. CONCLUSIONS: We did not find a negative off-hour effect on in-hospital mortality among severe trauma patients.

A safe procedure for connecting a continuous renal replacement therapy device into an extracorporeal membrane oxygenation circuit.

Patients receiving extracorporeal membrane oxygenation (ECMO) often require continuous renal replacement therapy (CRRT). The intra-circuit pressure of adult ECMO usually deviates from the physiological range. We investigated the use of CRRT connected to an ECMO circuit with physiological intra-circuit pressures (0-150 mmHg, defined as the "safety range") using an in vitro experiment involving a water-filled ECMO circuit. The intra-circuit pressure pre-pump, post-pump, and post-oxygenator were measured while varying the height of the pump or ECMO flow. The bypass conduit pressure and distance from the post-oxygenator port were measured to find the "safety point", where the bypass pressure remained within the safety range. Both drainage and return limbs of the CRRT machine were connected to the safety point and the inlet and outlet pressures of the hemofilter were recorded while varying the ECMO and CRRT flow. The pre-pump pressure only remained within the safety range for heights >75 cm (ECMO flow = 4 L/min) or ECMO flow <3.5 L min (height = 50 cm). The post-pump and post-oxygenator pressure was generally outside of the safety range. The bypass pressure decreased according to the distance from the post-oxygenator port and the safety point was found at 60 or 75 cm (in a 90-cm length conduit) regardless of ECMO flow. The hemofilter inlet and outlet pressures remained within the safety range for all conditions of ECMO and CRRT flow, findings validated in clinical cases. The bypass conduit within an ECMO circuit can be connected to a CRRT machine safely under physiological pressures in adult patients receiving ECMO.

Fewer REBOA complications with smaller devices and partial occlusion: evidence from a multicentre registry in Japan.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) performed by emergency physicians has been gaining acceptance as a less invasive technique than resuscitative thoracotomy. OBJECTIVE: To evaluate access-related complications and duration of occlusions during REBOA. METHODS: Patients with haemorrhagic shock requiring REBOA, from 18 hospitals in Japan, included in the DIRECT-IABO Registry were studied. REBOA-related characteristics were compared between non-survivors and survivors at 24 hours. 24-Hour survivors were categorised into groups with small (≤8 Fr), large (≥9 Fr) or unusual sheaths (oversized or multiple) to assess the relationship between the sheath size and complications. Haemodynamic response, occlusion duration and outcomes were compared between groups with partial and complete REBOA. RESULTS: Between August 2011 and December 2015, 142 adults undergoing REBOA were analysed. REBOA procedures were predominantly (94%) performed by emergency medicine (EM) physicians. The median duration of the small sheath (n=53) was 19 hours compared with 7.5 hours for the larger sheaths (P=0.025). Smaller sheaths were more likely to be removed using external manual compression (96% vs 45%, P<0.001). One case of a common femoral artery thrombus (large group) and two cases of amputation (unusual group) were identified. Partial REBOA was carried out in more cases (n=78) and resulted in a better haemodynamic response than complete REBOA (improvement in haemodynamics, 92% vs 70%, P=0.004; achievement of stability, 78% vs 51%, P=0.007) and allowed longer occlusion duration (median 58 vs 33 min, P=0.041). No statistically significant difference in 24-hour or 30-day survival was found between partial and complete REBOA. CONCLUSION: In Japan, EM physicians undertake the majority of REBOA procedures. Smaller sheaths appear to have fewer complications despite relatively prolonged placement and require external compression on removal. Although REBOA is a rarely performed procedure, partial REBOA, which may extend the occlusion duration without a reduction in survival, is used more commonly in Japan.

Nighttime is associated with decreased survival and resuscitation efforts for out-of-hospital cardiac arrests: a prospective observational study.

BACKGROUND: Whether temporal differences alter the clinical outcomes of patients with out-of-hospital cardiac arrest (OHCA) remains inconclusive. Furthermore, the relationship between time of day and resuscitation efforts is unknown. METHODS: We studied adult OHCA patients in the Survey of Survivors after Out-of-Hospital Cardiac Arrest in the Kanto Region (SOS-KANTO) 2012 study from January 2012 to March 2013 in Japan. The primary variable was 1-month survival. The secondary outcome variables were prehospital and in-hospital resuscitation efforts by bystanders, emergency medical services personnel, and in-hospital healthcare providers. Daytime was defined as 0701 to 1500 h, evening was defined as 1501 to 2300 h, and night was defined as 2301 to 0700 h. RESULTS: During the study period, 13,780 patients were included in the analysis. The patients with night OHCA had significantly lower 1-month survival compared to the patients with daytime OHCA (night vs. daytime, adjusted odds ratio (OR) 1.66; 95 % confidence interval (CI), 1.34-2.07; P < 0.0001). The nighttime OHCA patients had significantly shorter call-response intervals, bystander CPR, in-hospital intubation, and in-hospital blood gas analyses compared to the daytime and evening OHCA patients (call-response interval: OR 0.95 and 95 % CI 0.93-0.96; bystander CPR: OR 0.85 and 95 % CI 0.78-0.93; in-hospital intubation: OR 0.85 and 95 % CI 0.74-0.97; and in-hospital blood gas analysis: OR 0.86 and 95 % CI 0.75-0.98). CONCLUSIONS: There was a significant temporal difference in 1-month survival after OHCA. The nighttime OHCA patients had significantly decreased resuscitation efforts by bystanders and in-hospital healthcare providers compared to those with evening and daytime OHCA.

Novel Non-surgical Strategy of Severe Chest Trauma With Venovenous Extracorporeal Membrane Oxygenation, Angioembolization, and Bronchial Blocker: A Case Report.

Severe chest trauma often requires immediate intervention, typically involving open chest surgery. However, advancements in medical technology offer alternative approaches, such as endovascular therapy and venovenous extracorporeal membrane oxygenation (VV-ECMO). In a recent case, a middle-aged male cyclist was admitted after colliding with a vehicle, presenting in shock with multiple injuries, including cerebral contusion and rib fractures. Despite initial treatments such as chest tubes and blood transfusions, his condition remained unstable, with worsening respiratory failure and hemorrhagic shock. A multidisciplinary team devised a comprehensive treatment plan, utilizing VV-ECMO for oxygenation support, a bronchial blocker to localize the hematoma, and interventional radiology for hemothorax hemostasis. These interventions successfully stabilized the patient without resorting to open chest surgery. Endovascular therapy, alongside bronchial blockers, facilitated adequate hemostasis and hematoma localization, avoiding invasive procedures. VV-ECMO plays a crucial role in maintaining oxygenation during respiratory failure. Strategic anticoagulation with nafamostat mesylate prevented clotting in the ECMO circuit. This case highlights the effectiveness of minimally invasive strategies in managing severe chest trauma, preserving lung function, and improving outcomes. In refractory cases, VV-ECMO acts as a bridge to stabilize respiratory status before definitive treatment, while bronchial blockers localize hematomas, reducing the need for surgery. Interventional radiology offers a less invasive option for achieving hemostasis. Collaboration among medical specialties and innovative technologies is critical to successfully navigating complex chest trauma cases.

Age-adjusted 5-factor modified frailty index as a valuable tool for patient selection in bilateral simultaneous total knee arthroplasty.

Although bilateral simultaneous total knee arthroplasty (BSTKA) is an effective treatment for bilateral knee osteoarthritis, safety concerns and lack of precise patient selection criteria persist. The purpose of this retrospective study was to determine the complication rate and the role of frailty in patient selection for BSTKA. We analyzed data from 434 patients who underwent BSTKA between February 2012 and January 2021, examining demographic factors and preoperative blood test results. Complications occurred in 77 patients (18%), with anemia requiring transfusion being the most common (26 patients, 5.9%). In the univariate analysis, age ≥ 75 years, age-adjusted Charlson Comorbidity Index ≥ 5, age-adjusted 5-factor modified Frailty Index (aamFI-5) ≥ 3, hemoglobin ≤ 11.0 g/dL, albumin ≤ 3.5 g/dL, estimated glomerular filtration rate < 45 ml/dl/1.73 m2, and D-dimer ≥ 2.0 µg/mL contributed to postoperative complications (p < 0.05). Multivariate analysis identified aamFI-5 ≥ 3 as an independent risk factor (p = 0.002). Our findings underscore the practical utility of aamFI-5 in predicting complications after BSTKA, providing valuable guidance to surgeons in the selection of BSTKA candidates and ultimately improving clinical outcomes.

Median arcuate ligament syndrome presenting as hemorrhagic shock.

The major symptoms of median arcuate ligament syndrome, celiac axis stenosis, or occlusion compressed by the median arcuate ligament include eating-associated abdominal pain and weight loss. Because celiac stenosis increases retrograde collateral blood flow from the superior mesenteric artery to the celiac artery via the pancreaticoduodenal arcade, a pancreaticoduodenal artery aneurysm could occur at a low incidence rate. Rupture of the pancreaticoduodenal artery aneurysm and hemorrhagic shock are rare. In this report, we present 3 cases of patients who had been well with no abdominal symptoms until the day of admission, when they experienced sudden-onset intra-abdominal hemorrhage and shock. These 3 patients were admitted to the emergency department, and contrast-enhanced computed tomography and radiographic selective catheter angiography revealed intra-abdominal hemorrhage, stenosis of the celiac arteries, and dilated pancreaticoduodenal arcade. Case 1 demonstrated severe hemorrhagic shock, whereas case 2 demonstrated moderate shock. We treated ruptured pancreaticoduodenal artery aneurysms with coil embolization. Case 3 demonstrated complete celiac occlusion and moderate hemorrhagic shock, and no aneurysm was detected.

Ultrasound assessment is useful for evaluating balloon volume of resuscitative endovascular balloon occlusion of the aorta.

BACKGROUND: Endovascular balloon occlusion of the aorta (EBOA) increases proximal arterial pressure but may also induce life-threatening ischemic complications. Although partial REBOA (P-REBOA) mitigates distal ischemia, it requires invasive monitoring of femoral artery pressure for titration. In this study, we aimed to titrate P-REBOA to prevent high-degree P-REBOA using ultrasound assessment of femoral arterial flow. METHODS: Proximal (carotid) and distal (femoral) arterial pressures were recorded, and perfusion velocity of distal arterial pressures was measured by pulse wave Doppler. Systolic and diastolic peak velocities were measured among all ten pigs. Total REBOA was defined as a cessation of distal pulse pressure, and maximum balloon volume was documented. The balloon volume (BV) was titrated at 20% increments of maximum capacity to adjust the degree of P-REBOA. The distal/proximal arterial pressure gradient and the perfusion velocity of distal arterial pressures were recorded. RESULTS: Proximal blood pressure increased with increasing BV. Distal pressure decreased with increasing BV, and distal pressure sharply decreased by > 80% of BV. Both systolic and diastolic velocities of the distal arterial pressure decreased with increasing BV. Diastolic velocity could not be recorded when the BV of REBOA was > 80%. CONCLUSION: The diastolic peak velocity in the femoral artery disappeared when %BV was > 80%. Evaluation of the femoral artery pressure by pulse wave Doppler may predict the degree of P-REBOA without invasive arterial monitoring.

Uterine rupture successfully treated with a damage-control strategy of hysterectomy and resuscitative endovascular balloon occlusion of the aorta-assisted cardiopulmonary resuscitation.

Background: Uterine rupture is a major cause of postpartum hemorrhage (PPH) that requires surgery. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is also helpful for PPH. However, the effectiveness of REBOA in PPH with cardiac arrest is unknown. Case Presentation: A 40-year-old woman developed hemorrhagic shock due to uterine rupture after an induced delivery. She developed cardiac arrest, but was rescued by cardiopulmonary resuscitation (CPR), REBOA, a hysterectomy, and pelvic gauze packing. The hemodynamics were too unstable to move to the operating room. Then we initiated the CPR assisted with REBOA and decided to activate massive transfusion and perform laparotomy in the emergency room. She was finally discharged home without neurological sequelae. Conclusion: Our damage control strategy, including REBOA-assisted CPR, contributed to saving the life of a patient with a life-threatening PPH.

Fatal case of Capnocytophaga sepsis from a dog bite in a patient with splenic hypoplasia.

Background: Capnocytophaga canimorsus is an oral commensal bacteria in dogs and may cause severe infection following a dog bite. This is a case of fatal C. canimorsus sepsis with acute infectious purpura fulminans (AIPF) in a healthy patient with splenic hypoplasia. Case Presentation: A healthy 49-year-old man was admitted to the intensive care unit (ICU) for septic shock and AIPF 4 days after a dog bite to his mouth. Computed tomography revealed a small spleen measuring 53 cm3 but no other source of infection. Despite intensive care, the patient died of multiple organ failure and progressive shock on the fifth ICU day. Polymerase chain reaction of blood samples identified the C. canimorsus gene on a later day. Conclusion: Capnocytophaga canimorsus from dog bites may cause fatal AIPF. Splenic hypoplasia and bite wounds in well-perfused areas such as the oral cavity are possible risk factors for sepsis. All dog bites should warrant medical attention.

Contact-free assessments of respiratory rate and volume with load cells under the bed legs in ventilated patients: a prospective exploratory observational study.

Development of reliable noncontact unrestrained respiratory monitoring is capable of augmenting the safety of hospitalized patients in the recovery phase. We previously discovered respiratory-related centroid shifts along the long axis of the bed with load cells under the bed legs [bed sensor system (BSS)]. This prospective exploratory observational study examined whether noncontact measurements of respiratory-related tidal centroid shift amplitude (TA-BSS; primary variable) and respiratory rate (RR-BSS; secondary variable) were correlated with tidal volume (TV-PN) and respiratory rate (RR-PN), respectively, measured by pneumotachograph in 14 ICU patients under mechanical ventilation. Among the 10-min average data automatically obtained for a 48-h period, 14 data samples were randomly selected from each patient. Successfully and evenly selected 196 data points for each variable were used for the purpose of this study. A good agreement between TA-BSS and TV-PN (Pearson's r = 0.669) and an excellent agreement between RR-BSS and RR-PN (r = 0.982) were observed. Estimated minute ventilatory volume [3.86 · TA-BSS · RR-BSS (MV-BSS)] was found to be in very good agreement with true minute volume (MV-PN) (r = 0.836). Although Bland-Altman analysis evidenced accuracy of MV-BSS by a small insignificant fixed bias (-0.02 L/min), a significant proportional bias of MV-BSS (r = -0.664) appeared to produce larger precision (1.9 L/min) of MV-BSS. We conclude that contact-free unconstrained respiratory monitoring with load cells under the bed legs may serve as a new clinical monitoring system, when improved.NEW & NOTEWORTHY We previously discovered that four load cells placed under the bed legs capture a centroid shift during respiration in bedridden human subjects. In 14 ICU patients under mechanical ventilation, this study evidenced that contact-free measurements of respiratory rate, tidal volume, and minute ventilation with the load cells correlated well with those measured by pneumotachograph. Possible clinical usefulness of this approach as a new clinical respiratory monitor is indicated.

The Restrictive Red Blood Cell Transfusion Strategy for Critically Injured Patients (RESTRIC) trial: a cluster-randomized, crossover, non-inferiority multicenter trial of restrictive transfusion in trauma.

BACKGROUND: The efficacies of fresh frozen plasma and coagulation factor transfusion have been widely evaluated in trauma-induced coagulopathy management during the acute post-injury phase. However, the efficacy of red blood cell transfusion has not been adequately investigated in patients with severe trauma, and the optimal hemoglobin target level during the acute post-injury and resuscitation phases remains unclear. Therefore, this study aimed to examine whether a restrictive transfusion strategy was clinically non-inferior to a liberal transfusion strategy during the acute post-injury phase. METHODS: This cluster-randomized, crossover, non-inferiority multicenter trial was conducted at 22 tertiary emergency medical institutions in Japan and included adult patients with severe trauma at risk of major bleeding. The institutions were allocated a restrictive or liberal transfusion strategy (target hemoglobin levels: 7-9 or 10-12 g/dL, respectively). The strategies were applied to patients immediately after arrival at the emergency department. The primary outcome was 28-day survival after arrival at the emergency department. Secondary outcomes included transfusion volume, complication rates, and event-free days. The non-inferiority margin was set at 3%. RESULTS: The 28-day survival rates of patients in the restrictive (n = 216) and liberal (n = 195) strategy groups were 92.1% and 91.3%, respectively. The adjusted odds ratio for 28-day survival in the restrictive versus liberal strategy group was 1.02 (95% confidence interval: 0.49-2.13). Significant non-inferiority was not observed. Transfusion volumes and hemoglobin levels were lower in the restrictive strategy group than in the liberal strategy group. No between-group differences were noted in complication rates or event-free days. CONCLUSIONS: Although non-inferiority of the restrictive versus liberal transfusion strategy for 28-day survival was not statistically significant, the mortality and complication rates were similar between the groups. The restrictive transfusion strategy results in a lower transfusion volume. TRIAL REGISTRATION NUMBER: umin.ac.jp/ctr: UMIN000034405, registration date: 8 October 2018.

High versus low positive end-expiratory pressure setting in patients receiving veno-venous extracorporeal membrane oxygenation support for severe acute respiratory distress syndrome: study protocol for the multicentre, randomised ExPress SAVER Trial.

INTRODUCTION: While limiting the tidal volume to 6 mL/kg during veno-venous extracorporeal membrane oxygenation (V-V ECMO) to ameliorate lung injury in patients with acute respiratory distress syndrome (ARDS) is widely accepted, the best setting for positive end-expiratory pressure (PEEP) is still controversial. This study is being conducted to investigate whether a higher PEEP setting (15 cmH2O) during V-V ECMO can decrease the duration of ECMO support needed in patients with severe ARDS, as compared with a lower PEEP setting. METHODS AND ANALYSIS: The study is an investigator-initiated, multicentre, open-label, two-arm, randomised controlled trial conducted with the participation of 20 intensive care units (ICUs) at academic as well as non-academic hospitals in Japan. The subjects of the study are patients with severe ARDS who require V-V ECMO support. Eligible patients will be randomised equally to the high PEEP group or low PEEP group. Recruitment to the study will continue until a total of 210 patients with ARDS requiring V-V ECMO support have been randomised. In the high PEEP group, PEEP will be set at 15 cmH2O from the start of V-V ECMO until the trials for liberation from V-V ECMO (or until day 28 after the allocation), while in the low PEEP group, the PEEP will be set at 5 cmH2O. Other treatments will be the same in the two groups. The primary endpoint of the study is the number of ECMO-free days until day 28, defined as the length of time (in days) from successful libration from V-V ECMO to day 28. The secondary endpoints are mortality on day 28, in-hospital mortality on day 60, ventilator-free days during the first 60 days and length of ICU stay. ETHICS AND DISSEMINATION: Ethics approval for the trial at all the participating hospitals was obtained on 27 September 2022, by central ethics approval (IRB at Hiroshima University Hospital, C2022-0006). The results of this study will be presented at domestic and international medical congresses, and also published in scientific journals. TRIAL REGISTRATION NUMBER: The Japan Registry of Clinical Trials jRCT1062220062. Registered on 28 September 2022. PROTOCOL VERSION: 28 March 2023, version 4.0.

Minimising the biases in the observational study of resuscitative endovascular balloon occlusion of the aorta: a research protocol for a prospective study analysed with propensity score matching with time-varying covariates.

INTRODUCTION: Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been used as a bridge to definitive bleeding control of subdiaphragmatic injury. Since previous observational studies have poorly adjusted for confounding factors, it is necessary to incorporate REBOA-specific and time-varying covariates in the model. We hypothesised that REBOA improves the survival of haemodynamically unstable torso trauma patients after comparing the REBOA group with a matched control group (non-REBOA group). METHODS AND ANALYSIS: The Japanese Association for the Surgery of Trauma-REBOA Study is a prospective, multicentre, matched cohort study organised by the Clinical Trial Committee of the Japanese Association for the Surgery of Trauma. To minimise observational study biases, this study will prospectively register traumatic shock patients who require bleeding control within 60 min upon arrival at the emergency department, with in-hospital mortality as the primary outcome. After the data set is fixed, the missing values for all variables will be imputed using the multiple imputation technique. In the primary analysis, propensity scores for the probability of REBOA decision (regardless of the actual REBOA deployment) will be calculated from the baseline information using a logistic regression generalised linear mixed-effects model, which will be performed for both the REBOA use and non-REBOA use groups. ETHICS AND DISSEMINATION: This study was approved by the ethics committee of each participating hospital. The results will be disseminated to the participating hospitals, submitted to peer-reviewed journals for publication and presented at congresses. TRIAL REGISTRATION NUMBER: UMIN Clinical Trials Registry (UMIN000035458).

Organ perfusion during partial REBOA in haemorrhagic shock: dynamic 4D-CT analyses in swine.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) increases proximal blood pressure while inducing distal ischemia of visceral organs. The evaluation of distal ischemia severity during REBOA is a prerequisite for safe resuscitation of haemorrhagic shock patients with REBOA. We evaluated changes in blood flow and organ perfusion due to the degree of occlusion using dynamic 4D-computed tomography (CT). We compared the results with those of a previous study on euvolemic status. Delayed enhancement of the inferior vena cava (IVC) without retrograde flow was observed in the 4D-volume rendering images in the high-degree occlusion. The time-density curve (TDC) of the liver parenchyma (liver perfusion) and superior mesenteric vein (SMV) demonstrated a decreased peak density and a delayed peak in high-degree occlusion. The change rate of the area under the TDC of the liver and SMV decreased linearly as the degree of occlusion increased (PV, Y = -1.071*X + 106.8, r2 = 0.972, P = 0.0003; liver, Y = -1.050*X + 101.8, r2 = 0.933, P = 0.0017; SMV, Y = -0.985*X + 100.3, r2 = 0.952, P = 0.0009). Dynamic 4D-CT revealed less severe IVC congestion during P-REBOA in haemorrhagic shock than in euvolemia. Analyses of TDC of the liver and SMV revealed a linear change in organ perfusion, regardless of intravascular volume.