The mechanism for neurological deficits from carbon monoxide (CO) poisoning is unclear. In a series of 150 patients with CO poisoning, we found marked elevations of blood-borne inflammatory filamentous (F-) actin–coated microparticles (MPs), neutrophil activation, and a 90% reduction in the normal level of plasma gelsolin (pGSN), a protein capable of lysing F-actin–coated MPs. This led to studies in a murine model where the same events occur and cause neuroinflammation with cognitive dysfunction. All events are recapitulated when F-actin MPs are injected intravenously, which establishes a blood-to-brain-to-blood inflammatory cycle that persists for weeks. All changes, including cognitive dysfunction, can be abrogated by an injection of human recombinant pGSN within 2 weeks after CO poisoning. These findings demonstrate that CO-induced neurological injury has an inflammatory etiology. Because of MP-mediated communications between the brain and systemic circulation, CO-induced cognitive deficits may be reversible with a pharmaceutical intervention.

Lee JS, et al. J Korean Med Sci. 2021 Apr;36(18):e118. https://doi.org/10.3346/jkms.2021.36.e118

Introduction. Upper gastrointestinal bleeding (UGIB) is a potentially life-threatening gastrointestinal emergency, and effective management depends on early risk stratification. The GlasgowBlatchford and Rockall scores are commonly used prognostic measures for UGIB, although these scoring systems are relatively difficult to apply in early emergency settings. AIMS65 with five items, albumin, international normalized ratio, mental status, systolic blood pressure, and age (65 years), showed efficacy in predicting long-term hospitalization and mortality. This study aimed to investigate the usefulness of the prothrombin time-international normalized ratio-to-albumin ratio (PTAR) in the emergency room for early UGIB risk stratification. Methods. We retrospectively examined patients who visited a tertiary academic hospitals emergency department (ED) with UGIB as the chief presentation between January 2019 and December 2020. The cutoff values and diagnostic accuracies of the PTAR, GlasgowBlatchford score, AIMS65 score, pre-endoscopy, and complete Rockall score were analyzed, and the performance of the PTAR was compared with that of other risk stratification methods. In total, 519 patients were enrolled: 163 patients were admitted in the intensive care unit (ICU) and 35 died during admission. Multiple logistic regression analyses confirmed the association of the PTAR with ICU admission and mortality. The adjusted odd ratio (aOR) of the PTAR for ICU admission care was 8.376 (2.72225.774), and the aOR of the PTAR for mortality was 27.846 (8.70189.116). Conclusions. The PTAR measured in the ED is an independent factor related to ICU admission and mortality in patients with UGIB. Using ED blood laboratory results, which are reported relatively quickly and are easy to acquire and calculate, the PTAR can be used as a risk stratification marker in the early emergency setting.

Hyperbaric oxygen therapy (HBOT) has been used to provide oxygen to underperfused organs following ischemia or carbon monoxide intoxication. Various beneficial consequences of HBOT have been reported, including wound healing, anti-inflammatory action, and cell survival; however, the molecular mechanisms underlying these effects have not been elucidated yet. We applied a single HBOT program consisting of administration of 2.8 atmospheres absolute (ATA) for 45 min, followed by 2.0 ATA for 55 min, to 10 male volunteers without any metabolic disease. Within 1 week of HBOT, there was no alteration in serum biochemical variables, except for an increase in triglyceride content. As a mitochondrial stress indicator, the serum concentration of growth differentiation factor 15 was reduced by HBOT. The circulating level of γ–glutamyltransferase was also decreased by HBOT, suggesting an attenuation of oxidative stress. HBOT increased adiponectin and reduced leptin levels in the serum, leading to an elevated adiponectin/leptin ratio. This is the first study to investigate the effect of HBOT on serum levels of metabolic stress-related biomarkers. We suggest that HBOT attenuates mitochondrial and oxidative stresses, and relieves metabolic burdens, indicating its potential for use in therapeutic applications to metabolic diseases.

Background Fingertip injuries are the most common type of traumatic injury treated at emergency departments and require prompt and adequate interventions for favorable wound survival outcomes. Hyperbaric oxygen (HBO2) therapy is well known for its many positive effects on wound healing. We hypothesized that treatment with HBO2 would improve the graft survival outcomes of amputated fingertip injuries treated with composite grafts.Methods This retrospective observational study included fingertip amputations that were treated between January 2013 and December 2017. A conventional group and an HBO2 therapy group were statistically compared to evaluate the effect of HBO2 treatment. Graft survival was categorized as either success or failure.Results Among 55 cases (digits), 34 digits were conventionally treated, while 21 digits were treated with HBO2. No statistically significant differences were observed between the groups with regard to general characteristics. Among patients with guillotine-type injuries, the composite graft success rate was statistically significantly higher in the group that received HBO2 therapy than in the conventional group (P=0.0337). Overall, the HBO2 group also demonstrated a statistically significantly shorter healing time than the conventional group (P=0.0075). As such, HBO2 treatment facilitates composite graft survival in cases of fingertip injury.Conclusions HBO2 treatment was associated with an increased composite graft survival rate in guillotine-type fingertip injuries and reduced the time required for grafts to heal.

Background: Hyperbaric oxygen therapy (HBOT) involves inhaling nearly 100% oxygen in a pressurized environment and is commonly used to treat various diseases and injuries. Despite its well-known safety, HBOT is associated with side effects, with frequent middle ear barotrauma (MEB) and oxygen toxicity. Understanding the characteristics and risk factors associated with these side effects is critical for improving patient compliance and treatment outcomes. Methods: This retrospective multicenter study aimed to analyze the characteristics and factors associated with side effects during HBOT using a computer-controlled pressurized monoplace hyperbaric chamber. We conducted a retrospective observational study across the two tertiary hospitals in Korea, involving patients who received HBOT from October 2016 for one hospital and October 2017 for another hospital to June 2020. Data were extracted from electronic medical records and hyperbaric chamber logs, including patient demographics, medical history, HBOT indications, and details of side effects. Statistical analyses, including chi-square and t-tests, were used to compare variables. Results: A total of 247 patients (mean age: 59.35 ± 15.05 years, 63.56% male) were included. The most common indications for HBOT were sudden sensorineural hearing loss (27.94%) and post-graft/flap (24.29%). Hypertension (46.15%) and diabetes mellitus (39.27%) were the most frequent comorbidities. Otalgia was the most prevalent side effect (33.20%), followed by chest discomfort (2.02%) and headache (1.62%). A significant proportion of patients (11.74%) terminated HBOT due to side effects, with most pauses occurring at pressures between 1.2 and 1.4 ATA (26.67%). Side effects, particularly otalgia, significantly impact patient compliance with HBOT. Conclusions: The incidence of side effects varies by pressure level during treatment, suggesting the need for tailored strategies to minimize side effects. This study highlights the importance of patient monitoring and education to improve the safety and efficacy of HBOT in monoplace chambers.