伊澤 祥光

BACKGROUND: Traumatic diaphragmatic injury (TDI) is well-known worldwide as rare and life-threatening. However, because no nationwide cohort study of penetrating and blunt TDI has been conducted in Japan and other countries where penetrating trauma is relatively uncommon, the clinical characteristics of all TDI are unknown. We aimed to describe the characteristics of TDI patients, compare penetrating TDI with blunt TDI, and identify mortality risk factors in Japan. METHODS: We retrospectively identified TDI patients between 2004 and 2019 using data from the Japan Trauma Data Bank. We extracted data on patient demographics, type of trauma, cause of trauma, physiological parameters, region of concomitant injury, associated injury, and management. We compared penetrating and blunt TDI for each variable. The primary outcome was mortality. Multivariable logistic regression was performed to identify mortality risk factors. RESULTS: Of the 338,744 patients, 1,147 (0.3%) had TDI, of which 771 were eligible for analysis (excluding 308 in cardiac arrest on arrival). Penetrating TDI represented 29.8% and blunt TDI 70.2%, and comparing penetrating and blunt TDI, the most common cause was self-inflicted (48.7%) vs. accident (85.6%), males were 68.7% vs. 66.0% of the patients (P = 0.50), and the mortality rate was 8.3% vs. 26.4% (P < 0.001). Multivariable analysis found that age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.04), Injury Severity Score (OR 1.03, 95%CI 1.006-1.06), Revised Trauma Score (OR 0.55, 95%CI 0.45-0.67), severe concomitant abdominal injury (OR 2.45, 95%CI 1.32-4.56), severe concomitant upper extremity injury (OR 3.38, 95%CI 1.24-9.17) were independent predictors of mortality, and computed tomography (CT) (OR 0.32, 95%CI 0.15-0.69) and diaphragm repair (OR 0.44, 95%CI 0.25-0.78) were protective factors. CONCLUSIONS: In Japan, we found that penetrating TDI was mainly caused by self-injury and the male-female ratio was the same as for blunt TDI, although blunt TDI was much more frequent. TDI was considered highly lethal, with over 25% of patients in cardiac arrest on arrival. Our unique independent predictors were CT, severe concomitant abdominal injury, and severe concomitant upper extremity injury. These findings may help in the management of TDI in countries with less common penetrating trauma.

PURPOSE: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is beneficial for uncontrollable torso bleeding; however, prolonged REBOA causes ischemia-reperfusion injury. The purpose of this study is to examine the hypothesis that continuous renal replacement therapy (CRRT) with a cytokine-adsorbing hemofilter would improve mortality due to hemorrhagic shock with REBOA-reperfusion injury by controlling metabolic acidosis, hyperkalemia, and hypercytokinemia. METHODS: Hemorrhagic shock with 40% blood loss was induced by phlebotomy in eight female swine. CRRT was performed on four swine after 90 min of REBOA, and the remaining four swine (control group) underwent the same procedures except for CRRT. We evaluated the survival time and trends of pH, HCO3-, potassium, lactate, circulatory inflammatory cytokines, and histopathology of the intestine for 180 min after REBOA deflation. RESULTS: Two swine in the CRRT group and one in the control group survived; no significant difference were observed in survival rates between the groups (p = 0.45). Furthermore, no significant differences in the transition of biomarkers and histopathological grades were observed between the groups. The CRRT group showed a tendency of increasing pH and HCO3-, decreasing lactate, lower elevation of potassium and cytokine levels (interleukin 6, CRRT: 1008.5 [770.4-1246.6], control; 1636.7 [1636.7-1636.7] pg/mL at t = 270), and lower intestine histopathological grade (jejunum, CRRT; 1.5 [1.3-1.8], control; 4.0 [4.0-4.0], ileum, CRRT; 1.5 [1.3-1.8], control; 4.0 [4.0-4.0] at t = 270) than the control group. CONCLUSIONS: CRRT may mitigate acute-REBOA-related ischemia-reperfusion injury by controlling biomarkers. Further research is required to evaluate the impact on long-term mortality.

BACKGROUND Inferior vena cava (IVC) injury is a potentially fatal injury with a high mortality rate of 34-70%. In cases in which the patient's condition is stable, diagnosis by computed tomography (CT) is the criterion standard. Findings on CT include retroperitoneal hematoma around the IVC, extravasation of contrast medium, and abnormal morphology of the IVC. We report a case of an IVC injury that could not be diagnosed by preoperative CT examination and could not be immediately detected during laparotomy. CASE REPORT A 73-year-old woman had stabbed herself in the neck and abdomen at home using a knife. When she arrived at our hospital, we found a stab wound several centimeters long on her abdomen and a cut approximately 15 cm long on her neck. We activated the massive transfusion protocol because she was in a condition of hemorrhagic shock. After blood transfusion and blood pressure stabilization, contrast-enhanced computed tomography (CT) revealed a small amount of fluid in the abdominal cavity. An otorhinolaryngologist performed successful drainage and hemostasis, and a laparotomy was performed. Gastric injury and mesentery injury of the transverse colon were identified and repaired with sutures. Subsequent search of the retroperitoneum revealed massive bleeding from an injury to the inferior vena cava (IVC). The IVC was repaired. Postoperative progress was good, and she was discharged from the hospital 65 days after her injuries. CONCLUSIONS We experienced a case of penetrating IVC injury, which is a rare trauma. Occult IVC injury may escape detection by preoperative CT examination or during laparotomy.

AIM: Non-occlusive mesenteric ischemia (NOMI) is associated with high mortality rates, but definitive treatments have not yet been established. Although experimental animal models are worthwhile, reproducible models that reflect the pathophysiology of NOMI have not been developed. METHODS: We combined risk factors for NOMI, comprising hemorrhagic shock, systemic vasopressor infusion, and local vasopressor infusion from the superior mesenteric artery (SMA) in swine under maintained anesthesia. Experiment 1 involved full-intensity (40%) phlebotomy and systemic vasopressor (norepinephrine and epinephrine). Experiment 2 involved full-intensity (40%) phlebotomy, systemic norepinephrine, and local vasopressor infusion into the SMA. Experiment 3 involved moderate (27%) phlebotomy, systemic norepinephrine infusion, and local epinephrine infusion. We evaluated serum lactate levels, intestinal serosa color, computed tomography (CT) angiography, and pathological findings. RESULTS: After inducing hemorrhage, systemic vasopressor alone and in combination with local vasopressin or norepinephrine infusion did not induce ischemic color changes in the intestine. The combination of systemic norepinephrine and local epinephrine (0.5 μg/kg/min) after moderate (27% blood loss) hemorrhage induced gross color change, pathological destruction, and elevation of serum lactate. Patent flow in the SMA was confirmed on CT angiography. CONCLUSION: We established a swine NOMI model with systemic norepinephrine infusion and local epinephrine with moderate hemorrhagic shock.

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.

BACKGROUND: In recent years, various home-use health devices have gained popularity. The abdominal roller is one of these. Spinal cord injury without radiological abnormality is known to occur even with relatively minor injuries, but there are few reports of such injuries caused by a roller. CASE PRESENTATION: Two cases of spinal cord injuries caused by a roller are reported. In both cases, injuries occurred during the standing rollout by a patient in an inebriated state, and the patients were rushed to an emergency department. CONCLUSION: Because the use of abdominal rollers may result in extremely serious disabilities, it is necessary to emphasize the appropriate use of such equipment.

Blast injuries caused by an improvised explosive device (IED) are becoming more common in civilian settings. However, physicians may not be familiar with the treatment and management of blast-injured victims. To the best of our knowledge, this is the first case report of a blast injury caused by an IED in Japan. A 64-year-old man was admitted to our hospital's emergency department after sustaining a blast injury. His vital signs were stable, but he had multiple small wounds with embedded foreign bodies that were consistent with injuries sustained by IED victims. The patient was treated for his injuries and was moved to another hospital on day 37. Knowledge about blast injuries caused by IEDs and management strategies for mass casualties are both necessary.

BACKGROUND Centipede envenomation is usually mild, but a review of the existing literature revealed a more serious course in a small proportion of patients. In fact, necrotizing soft-tissue infections have been reported following centipede stings in a small number of cases and require early diagnosis and treatment because of a high mortality rate. CASE REPORT A 78-year-old man was stung by a centipede on the left abdomen. Treatment with antimicrobial agents was started due to cellulitis, but extensive erythema developed from the left chest to the left buttock. Six days after being stung, he visited our hospital. Necrotizing soft-tissue infection was diagnosed and treated immediately with antibiotics and debridement on the left side of the abdomen and chest. Group A Streptococcus was detected in the fascia. The wound was left partially open and washed daily, resulting in gradual improvement of the wound condition. On hospitalization day 8, the open wound was able to be closed. Antimicrobial therapy was completed on hospitalization day 16. The patient showed good progress. CONCLUSIONS Centipede stings are not rare in tropical and subtropical regions, and most occurrences of centipede envenomation cause only local symptoms. However, we believe that even wounds caused by centipedes should be monitored, given the possibility of subsequent severe infection, as in the present case. In addition, the causative organisms identified in the present patient with necrotizing soft-tissue infection following a centipede sting were commensal bacteria of the skin. Future research is thus needed to clarify the relationship between these causative organisms and centipedes.

50歳代男性。トラックを運転中, 停車していたトラックに追突して受傷した。精査のComputed tomography (CT) にて両側外傷性気胸・骨盤骨折に加えて左総頸動脈の造影途絶を認めた。左内頸動脈および左外頸動脈は造影されていた。頭蓋内に梗塞所見はないため慎重に経過観察していたが, 来院14時間後に右片麻痺と意識レベルの低下が出現した。magnetic resonance imaging (MRI) で左中大脳動脈領域の脳梗塞を認めた。骨盤骨折の手術後から抗凝固療法を開始した。失語と麻痺は残存したが神経症状は増悪なく経過し, 約2カ月後に転院した。鈍的外傷による総頸動脈閉塞はまれな疾患であるが, 神経症状出現率・死亡率がともに高率である。治療として抗血小板薬の有用性が報告されているが, 多発外傷の患者においては出血増悪によるリスクも加味する必要があり, 治療には今後さらなる検討が必要と考えられた。

BACKGROUND: Unnecessary whole-body computed tomography (CT) may lead to excess radiation exposure. Serum D-dimer levels have been reported to correlate with injury severity. We examined the predictive value of serum D-dimer level for identifying patients with isolated injury that can be diagnosed with selected-region CT rather than whole-body CT. METHODS: This single-center retrospective cohort study included patients with blunt trauma (2014-2017). We included patients whose serum D-dimer levels were measured before they underwent whole-body CT. "Isolated" injury was defined as injury with Abbreviated Injury Scale (AIS) score ≤ 5 to any of five regions of interest or with AIS score ≤ 1 to other regions, as revealed by a CT scan. A receiver operating characteristic curve (ROC) was drawn for D-dimer levels corresponding to isolated injury; the area under the ROC (AUROC) was evaluated. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for several candidate cut-off values for serum D-dimer levels. RESULTS: Isolated injury was detected in 212 patients. AUROC was 0.861 (95% confidence interval [CI]: 0.815-0.907) for isolated injury prediction. Serum D-dimer level ≤ 2.5 μg/mL was an optimal cutoff value for predicting isolated injury with high specificity (100.0%) and positive predictive value (100.0%). Approximately 30% of patients had serum D-dimer levels below this cutoff value. CONCLUSION: D-dimer level ≤ 2.5 μg/mL had high specificity and high positive predictive value in cases of isolated injury, which could be diagnosed with selected-region CT, reducing exposure to radiation associated with whole-body CT.