Ischemia reperfusion (IR) injury occurs when blood supply, perfusion, and concomitant reoxygenation is restored to an organ or area following an initial poor blood supply after a critical time period. Ischemia reperfusion injury contributes to mortality and morbidity in many pathological conditions in emergency medicine clinical practice, including trauma, ischemic stroke, myocardial infarction, and post‐cardiac arrest syndrome. The process of IR is multifactorial, and its pathogenesis involves several mechanisms. Reactive oxygen species are considered key molecules in reperfusion injury due to their potent oxidizing and reducing effects that directly damage cellular membranes by lipid peroxidation. In general, IR injury to an individual organ causes various pro‐inflammatory mediators to be released, which could then induce inflammation in remote organs, thereby possibly advancing the dysfunction of multiple organs. In this review, we summarize IR injury in emergency medicine. Potential therapies include pharmacological treatment, ischemic preconditioning, and the use of medical gases or vitamin therapy, which could significantly help experts develop strategies to inhibit IR injury.

Cushing’s reflex usually results from intracranial hypertension. Although Cushing’s sign can implicate severe traumatic brain injury (TBI) in injured patients, no major investigations have been made. The purpose of this study was to assess the predictability of life-threatening brain injury requiring immediate neurosurgical intervention (LT-BI) among trauma patients with Cushing’s sign in the prehospital setting. This was a retrospective study using data from the Japan Trauma Data Bank from the period of 2010 to 2014. Patients 16 years old or older with blunt mechanisms of injury who were transported directly from the scene and Glasgow Coma Scale for eye opening of one in the prehospital setting were included. LT-BI was defined as patients requiring burr hole evacuation or craniotomy within 24 h of hospital arrival and patients who were non-survivors due to isolated severe TBI. Prehospital systolic blood pressure (pSBP) and heart rate (pHR) were assessed using area under the receiver operating characteristic curve (AUROC) and multiple logistic regression analysis to predict LT-BI. Of 6332 eligible patients, 1859 (29%) exhibited LT-BI. AUROC of LT-BI using pSBP and pHR was 0.666 (95% confidence interval (CI); 0.652–0.681, P < 0.001), and 0.578 (95% CI; 0.563–0.594, P < 0.001), respectively. AUROC of pSBP was the highest among the 60 ≤ pHR ≤ 99 subgroup, of which AUROC was 0.680 (95% CI; 0.662–0.699, P < 0.001). Multiple logistic regression analysis showed that the higher the pSBP and the lower the pHR, the more likely that the patients had LT-BI. In a group with pSBP ≥ 180 mmHg and pHR ≤ 59 beats/min, the odds ratio and 95% CI of LT-BI after adjusting for age, sex, and severity of injuries to other body regions was 4.77 (2.85–7.97), P < 0.001 was compared with the reference group, which was defined as patients with normal vital signs. Our study has found that the combination of hypertension and bradycardia, which are the components of Cushing's sign without eye opening in the prehospital setting was a weak but a significant predictor of LT-BI, or death due to possible isolated severe TBI. Prehospital Cushing’s sign with disturbed level of consciousness in trauma patients was a weak but significant predictor of the need for immediate neurosurgical intervention.

In Japan, nafamostat mesylate (NM) is frequently used as an anticoagulant during continuous renal replacement therapy (CRRT). The dialyzer membrane AN69ST has been reported to adsorb NM and affect the management of anticoagulant therapy. However, the adsorbed amount has not yet been quantitatively assessed. Therefore, in this study, we evaluated the pre- and post-hemofilter prolongation of the activated clotting time (ACT) in patients with AN69ST and PS membranes. We also measured the adsorption of NM in three types of CRRT membranes using an experimental model. In a study of patients who underwent CRRT using AN69ST or PS membranes in 2015 at the Advanced Emergency and Critical Care Center, Okayama University Hospital, pre- and post-hemofilter ACT measurements were extracted retrospectively, and the difference was calculated. In addition, AN69ST (sepXiris100), PS (HEMOFEEL SHG-1.0), and PMMA membranes (HEMOFEEL CH-1.0N) were used in an in vitro model of a dialysis circuit, and the concentrations of NM were measured in pre- and post-hemofilter membranes and filtrates. The ACT difference was significantly lower in the group using AN69ST membranes (p < 0.01). In the in vitro model (n = 4) with adsorption and filtration, the post-hemofilter and filtrate concentrations of NM in AN69ST membranes were significantly lower than those in the PS and PMMA membranes (p < 0.01). The NM adsorption clearance of the AN69ST membrane was significantly higher than that of the PS and PMMA membranes. The AN69ST membrane had higher NM adsorption than the PS and PMMA membranes. This may have resulted in the lower ACT difference in patients undergoing CRRT using the AN69ST membrane than in patients undergoing CRRT using PS or PMMA membranes.

Aim: Although uncommon, medical emergencies arise in general dental practice. Inadequate data on their severity and frequency makes targeting medical education for general dental practitioners difficult. This also makes planning for unexpected events challenging for practitioners and makes collaborating with emergency physicians burdensome. We aimed to clarify the incidence and characteristics of a dental outpatient department’s medical emergencies.Methods: This single‐center, retrospective, observational study was undertaken with patients who visited the dental outpatient department of Okayama University Hospital during the 8‐year period. The primary outcome of the study was to identify the incidence and characteristics of medical emergencies in the dental outpatient department. Then we examined the timing of medical emergencies, administered medications, and final disposition (home/admission).Results: During the period, 1,146,929 patients were enrolled. Forty‐two patients (0.0037%) were consulted as medical emergencies. More than 60% of the incidents were vasovagal syncope, and dehydration and hypoglycemia were the second most prevalent at 9.5%. The most common types of dental treatments were tooth extraction (45.2%), followed by general dental treatment (28.6%), and other dental surgery such as implant placement (14.3%). Types of medical emergencies occurred equally before, during, and after dental treatment. Antihypertensive agents, sedatives, or glucose were used. For patients with emergencies, 90.5% recovered during the day and returned home, and 9.5% were hospitalized.Conclusion: The incidence of medical emergencies was low in our dental outpatient department. Knowledge of basic management principles, regular education for emergency care, and practicing first aid skills are mandatory for safe patient management.

Identifying dysphagia as a potential complication of sepsis may improve swallowing function and survival while decreasing hospital length of stay. Our goal was to determine the frequency of dysphagia in sepsis survivors on the 7th day after admission, as well as their associated factors and outcomes. This single-centre, retrospective, observational study analysed data from sepsis survivors admitted to Okayama Saiseikai General Hospital from 2018 to 2019. Participants with sepsis were assigned to one of two study groups based on the presence or absence of dysphagia using the criterion of Functional Oral Intake Scale score <5 on the 7th day after admission. We used multivariate logistic regression to determine factors independently associated with dysphagia on the 7th day after admission. Multivariate logistic regression was also used to determine associations between groups and outcomes, including dysphagia on hospital discharge, direct discharge home (discharge of patients directly to their home), and total dependency (Barthel Index score ≤20) on hospital discharge. One hundred one patients met the study inclusion criteria, 55 with dysphagia and 46 without dysphagia. Fasting period (adjusted odds ratio [AOR]: 1.31, 95% confidence interval [CI]: 1.07-1.59) and enteral tube feeding (AOR: 8.56, 95% CI: 1.95-37.5) were independently associated with the presence of dysphagia on the 7th day after admission. Dysphagia on the 7th day after admission was associated with dysphagia on hospital discharge (AOR: 46.0, 95%, CI: 7.90-268.3), a lower chance of direct discharge home (AOR: 0.03, 95% CI: 0.01-0.15), and a higher incidence of total dependency (AOR: 9.30, 95% CI: 2.68-32.2). We found that dysphagia was commonly encountered post sepsis. Fasting period and enteral tube feeding were independently associated with dysphagia on the 7th day after admission. Dysphagia on the 7th day after admission was also associated with dysphagia on hospital discharge, nondirect discharge home, and dependency in activities of daily living at the time of hospital discharge.

Because inhaled carbon monoxide (CO) provides potent anti-inflammatory and antioxidant effects against ischemia reperfusion injury, we hypothesized that treatment of organ donors with inhaled CO would decrease graft injury after heart transplantation. Hearts were heterotopically transplanted into syngeneic Lewis rats after 8 hours of cold preservation in University of Wisconsin solution. Donor rats were exposed to CO at a concentration of 250 parts per million for 24 hours via a gas-exposure chamber. Severity of myocardial injury was determined by total serum creatine phosphokinase and troponin I levels at three hours after reperfusion. In addition, Affymetrix gene array analysis of mRNA transcripts was performed on the heart graft tissue prior to implantation. Recipients of grafts from CO-exposed donors had lower levels of serum troponin I and creatine phosphokinase; less upregulation of mRNA for interleukin-6, intercellular adhesion molecule-1, and tumor necrosis factor-α; and fewer infiltrating cells. Although donor pretreatment with CO altered the expression of 49 genes expressly represented on the array, we could not obtain meaningful data to explain the mechanisms by which CO potentiated the protective effects.Pretreatment with CO gas before organ procurement effectively protected cardiac grafts from ischemia reperfusion-induced injury in a rat heterotopic cardiac transplant model. A clinical report review indicated that CO-poisoned organ donors may be comparable to non-poisoned donors.