Guangkai Gao

Background: Carbon monoxide (CO) poisoning remains a major cause of accidental injuries and multiple studies have indicated that CO is also associated with significantly severe or long-term toxicity to the central nervous system. Given that CO poisoning causes serious morbidity and mortality, a better understanding of epidemiological features and clinical characteristics of acute CO poisoning in China is crucial. Methods: We collected the clinical data of acute CO poisoning in patients between November 2019 and April 2020 across Shandong province, China and analyzed its characteristics focusing on the weekly amount and the severity of the confirmed cases. Results: A total number of 21,088 acute CO poisoning cases were diagnosed. The overall incidence of acute CO poisoning was approximately 0.021%. On severity rankings, 63% of confirmed cases ( n = 13,378) were mild, 27% (n = 5635) were moderate, and 10% ( n = 2075) were severe. Interestingly, the coastal cities had more confirmed cases than the inland/suburban areas in Shandong. Meanwhile, the number of confirmed cases was negatively correlated with the local mean daily temperature ( P = 0.0167). Conclusions: Mild acute CO poisoning cases accounted for the majority of all confirmed cases during the winter of 2019. In Shandong province, which is located in east China, residents of the coastal cities are more susceptible to CO poisoning than residents of inland cities.

Objectives: (1) To examine whether hyperbaric oxygen (HBO2) will inhibit growth of multidrug-resistant Klebsiella pneumoniae (MDR-K. pneumoniae) and extensively drug-resistant Klebsiella pneumoniae (XDR-K. pneumoniae); (2) To determine whether the effect of tigecycline on XDR-K. pneumoniae will be enhanced by HBO2. Methods: The effects of 1.5 hours of treatment with normoxia (21% O2, 1 atmosphere absolute/ATA) or HBO2 (100% O2, 2 ATA) on bacterial counts of eight isolates of MDR-K. pneumoniae and eight isolates of XDRK. pneumoniae were studied. The effects of five hours of treatment with normoxia (21% O2, 1 ATA), tigecycline (21% O2, 1 ATA), HBO2 (100% O2, 3 ATA) or HBO2 + tigecycline (100% O2, 3 ATA) on proliferation of 10 isolates of XDR-K. pneumoniae were investigated. Results: HBO2 at 100% O2, 2 ATA, 1.5 hours suppressed growth of MDR-K. pneumoniae but had no effect on XDR-K. pneumoniae. HBO2 at 100% O2, 3 ATA, five hours enhanced the effects of tigecycline on XDR-K. pneumoniae. Conclusion: HBO2 in combination with or without tigecycline can be used to eliminate K. pneumoniae in vitro, and such treatment may be beneficial for patients with infections caused by K. pneumoniae.

Images in Clinical Medicine from The New England Journal of Medicine — Decompression Sickness

Mechanical ventilation with positive end-expiratory pressure (PEEP) has been advocated as an essential life support for critical patients. However, its side effect, which is demonstrated by an elevation of intracranial pressure (ICP) under normobaric (NBO2) conditions, is potentially detrimental to patients. Hyperbaric oxygen (HBO2) therapy, on the other hand, is frequently applied for the same group of patients, and its efficacy is shown by maintaining a higher PaO2 and a reduced ICP. Our study investigated the effect of HBO2 and NBO2 on ICP with or without PEEP ventilation on healthy dogs by comparing cerebrospinal fluid pressure (CSFP) and concluded that the elevation of PEEP resulted in a significant increase of ICP (CSFP) under both conditions (p < 0.05). HBO2 leads to a lower ICP increase compared to the NBO2 group. Under the same level of PEEP, the joint use of PEEP and HBO2 is safe and highly practical in clinical medicine.

To investigate the magnetic resonance imaging (MRI) features of spinal cord decompression sickness (DCS) on compressed-air divers, we hereby report seven cases diagnosed with spinal cord DCS. Only two patients out of seven showed positive MRI findings: A detailed case report will be provided on each. In one of the cases, the MRI revealed extensive high signal within the central gray matter of the spinal cord. The other one showed patchy high signal on T2-weighted images as well as diffusion-weighted images (DWI) in the dorsal column white matter of the spinal cord. The findings in our collective suggest that the MRI focused on the spinal cord is not always appropriate for obtaining a quick diagnosis. The discrepancy between MRI findings and clinical evolution leads to the conclusion that MRI focused on the spinal cord does not always correlate with neurological improvement. Decision for hyperbaric oxygen (HBO2) treatment should not be based primarily on MRI findings.