A Case of Myositis in Patient with Atypical Bacterial Pneumonia

Case report - Introduction: Bacterial community-acquired atypical pneumonia is sometimes complicated by myositis or by renal parenchymal disease. They can present with myositis and present with muscle weakness, pain or swelling, and elevated muscle enzymes. We present the case of a patient with lower limb weakness and raised creatinine kinase with atypical pneumonia caused by Legionella pneumophila. Case report - Case description: A 76-year-old Caucasian man, who was previously fit and independent and walked 3 miles every day presented with a 1-week history of progressive leg weakness, and inability to mobilize. He had a fall and was on the floor for 2 hours. He had a background history of hypercholesterolemia and was on atorvastatin for 15 years. On his vital observation, he was found tachypnoeic, tachycardic, and hypoxic. He had a right upper lobe crackle but he didn't have respiratory symptoms. His muscle power in his leg was 3/5 with carpet burns on knees and elbow. Initial investigation showed raised inflammatory marker CRP 412mg/L, AKI stage 1, and CK 43400 IU/L. His CXR showed dense right upper lobe consolidation. Legionella urinary antigen was positive. Myositis myoblot, ANA, ANCA negative. COVID-19 swab negative. Treated with IV antibiotic, supplemental oxygen, and IV fluid. Transferred to ITU due to worsening of hypoxia and kidney function. Interestingly, the CK level had improved significantly within 48 hours along with clinical improvement in his symptoms. There was no role of steroid or immunosuppressant due to his significant clinical improvement. On day 7 he was off oxygen, kidney function improved, had physiotherapy, and transferred to ward and on day 10 he was ambulant and discharged home. Case report - Discussion: To date, very few case reports of myositis in a patient with atypical pneumonia have been reported. The mechanism underlying acute myositis in atypical pneumonia is still unknown. The present analysis points out that the organism underlying atypical bacterial pneumonia may occasionally invade the muscle tissue thereby inducing both myositis and secondary kidney damage. Case report - Key learning points: We should be aware of this rare complication of atypical pneumonia and the resolution of symptoms that occur with the treatment of pneumonia. This would avoid unnecessary investigation and use of steroid.

Optical Monitoring of Breathing Patterns and Tissue Oxygenation: A Potential Application in COVID-19 Screening and Monitoring.

The worldwide outbreak of the novel Coronavirus (COVID-19) has highlighted the need for a screening and monitoring system for infectious respiratory diseases in the acute and chronic phase. The purpose of this study was to examine the feasibility of using a wearable near-infrared spectroscopy (NIRS) sensor to collect respiratory signals and distinguish between normal and simulated pathological breathing. Twenty-one healthy adults participated in an experiment that examined five separate breathing conditions. Respiratory signals were collected with a continuous-wave NIRS sensor (PortaLite, Artinis Medical Systems) affixed over the sternal manubrium. Following a three-minute baseline, participants began five minutes of imposed difficult breathing using a respiratory trainer. After a five minute recovery period, participants began five minutes of imposed rapid and shallow breathing. The study concluded with five additional minutes of regular breathing. NIRS signals were analyzed using a machine learning model to distinguish between normal and simulated pathological breathing. Three features: breathing interval, breathing depth, and O2Hb signal amplitude were extracted from the NIRS data and, when used together, resulted in a weighted average accuracy of 0.87. This study demonstrated that a wearable NIRS sensor can monitor respiratory patterns continuously and non-invasively and we identified three respiratory features that can distinguish between normal and simulated pathological breathing.

Performance Assessment of a Commercial Continuous-Wave Near-Infrared Spectroscopy Tissue Oximeter for Suitability for Use in an International, Multi-Center Clinical Trial.

Despite the wide range of clinical and research applications, the reliability of the absolute oxygenation measurements of continuous wave near-infrared spectroscopy sensors is often questioned, partially due to issues of standardization. In this study, we have compared the performances of 13 units of a continuous wave near-infrared spectroscopy device (PortaMon, Artinis Medical Systems, NL) to test their suitability for being used in the HEMOCOVID-19 clinical trial in 10 medical centers around the world. Detailed phantom and in vivo tests were employed to measure the precision and reproducibility of measurements of local blood oxygen saturation and total hemoglobin concentration under different conditions: for different devices used, different operators, for probe repositioning over the same location, and over time (hours/days/months). We have detected systematic differences between devices when measuring phantoms (inter-device variability, <4%), which were larger than the intra-device variability (<1%). This intrinsic variability is in addition to the variability during in vivo measurements on the forearm muscle resulting from errors in probe positioning and intrinsic physiological noise (<9%), which was also larger than the inter-device differences (<3%) during the same test. Lastly, we have tested the reproducibility of the protocol of the HEMOCOVID-19 clinical trial; that is, forearm muscle oxygenation monitoring during vascular occlusion tests over days. Overall, our conclusion is that these devices can be used in multi-center trials but care must be taken to characterize, follow-up, and statistically account for inter-device variability.