Pathological Presence of Free Air in the Thorax: Pneumothorax and Pneumomediastinum as a Complication of COVID-19.

INTRODUCTION: The abnormal presence of free air in the thorax, pneumothorax, and pneumomediastinum are complications for critically ill patients suffering from coronavirus disease 2019 (COVID-19). The development of these events may lead to a poor prognosis and make the management of this category of patients more difficult. STUDY DESIGN: We performed an observational retrospective study, including patients with SARS-CoV-2 infection and pneumonia who were hospitalized, to analyze the cases that developed pneumothorax or pneumomediastinum as a complication. RESULTS: A total of 28 cases (1.51%) from 1844 patients with SARS-CoV-2 pneumonia developed pneumothorax or pneumomediastinum during hospitalization. Of them, 21 (75%) needed intensive care unit admission and ventilation, and 10 (35.71) were cured. CONCLUSION: The male gender is more probable to be involved in the development of pneumothorax or pneumomediastinum in patients with SARS-CoV-2 pneumonia. The incidence of these events is low, and conservative treatment could provide a better outcome.

Complications During Hospitalization in Patients With SARS-CoV-2 Pneumonia in a Romanian Pulmonary Center.

Introduction The coronavirus disease (COVID-19) was declared a pandemic by the World Health Organization (WHO) on March 11, 2020. Facing a new and unknown virus, the entire medical community made considerable efforts to find a specific treatment, develop guidelines, and even create a vaccine. Besides all the measures taken, a wide range of complications associated with the disease increased the mortality and morbidity rates, adding more difficulty to the management of the patients. Study design We performed a retrospective study, including the patients with SARS-CoV-2 pneumonia who were admitted to our hospital between March 2020 and August 2021. We analyzed complications that developed during the hospitalization, such as respiratory failure or acute injury to other organs (the heart, pancreas, kidneys, and liver), and whether they were treatment- and hospitalization-related. Results One thousand eight hundred and forty-four cases were evaluated, and we analyzed the complications that developed during the hospitalization. Out of this, 1392 (75.48%) cases developed at least one complication during hospitalization, most frequently respiratory failure (71.14%), hyperglycemia (43.54%), renal injury (42.67%), or cardiovascular events (7.10%). Conclusion SARS-CoV-2 infection in hospitalized patients with pneumonia can cause injuries to any organ, making the management of those patients even more difficult.

Comparative analysis of Staphylococcus aureus and Escherichia coli microcalorimetric growth.

BACKGROUND: Microcalorimetric bacterial growth studies have illustrated that thermograms differ significantly with both culture media and strain. The present contribution examines the possibility of discriminating between certain bacterial strains by microcalorimetry and the qualitative and quantitative contribution of the sample volume to the observed thermograms. Growth patterns of samples of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) were analyzed. Certain features of the thermograms that may serve to distinguish between these bacterial strains were identified. RESULTS: The thermograms of the two bacterial strains with sample volumes ranging from 0.3 to 0.7 ml and same initial bacterial concentration were analyzed. Both strains exhibit a roughly 2-peak shape that differs by peak amplitude and position along the time scale. Seven parameters corresponding to the thermogram key points related to time and heat flow values were proposed and statistically analyzed. The most relevant parameters appear to be the time to reach a heat flow of 0.05 mW (1.67 ± 0.46 h in E. coli vs. 2.99 ± 0.53 h in S. aureus, p < 0.0001), the time to reach the first peak (3.84 ± 0.5 h vs. 5.17 ± 0.49 h, p < 0.0001) and the first peak value (0.19 ± 0.02 mW vs. 0.086 ± 0.012 mW, p < 0.0001). The statistical analysis on 4 parameters of volume-normalized heat flow thermograms showed that the time to reach a volume-normalized heat flow of 0.1 mW/ml (1.75 ± 0.37 h in E. coli vs. 2.87 ± 0.65 h in S. aureus, p < 0.005), the time to reach the first volume-normalized peak (3.78 ± 0.47 h vs. 5.12 ± 0.52 h, p < 0.0001) and the first volume-normalized peak value (0.35 ± 0.05 mW/ml vs. 0.181 ± 0.040 mW/ml, p < 0.0001) seem to be the most relevant. Peakfit® decomposition and analysis of the observed thermograms complements the statistical analysis via quantitative arguments, indicating that: (1) the first peak pertains to a faster, "dissolved oxygen" bacterial growth (where the dissolved oxygen in the initial suspension acts as a limiting factor); (2) the second peak indicates a slower "diffused oxygen" growth that involves transport of oxygen contained in the unfilled part of the microcalorimetric cell; (3) a strictly fermentative growth component may slightly contribute to the observed complex thermal signal. CONCLUSION: The investigated strains of Staphylococcus aureus and Escherichia coli display, under similar experimental conditions, distinct thermal growth patterns. The two strains can be easily differentiated using a selection of the proposed parameters. The presented Peakfit analysis of the complex thermal signal provides the necessary means for establishing the optimal growth conditions of various bacterial strains. These conditions are needed for the standardization of the isothermal microcalorimetry method in view of its further use in qualitative and quantitative estimation of bacterial growth.

[Microcalorimetry -- a new method for bacterial characterisation]. / Microcalorimetria -- metoda noua de caracterizare bacteriana.

The microcalorimetry is a method used for recording of the heat produced by a thermodinamic system in a scale of micronanojouls. One of the domains in which this method is used is the one called bacterial microcalorimetry, which studies the heat generated by the bacterial populations. The process of bacterial growth can be monitored in real time by the recording a graph of the generated power over time. The modern isothermal microcalorimeters allow the detection of a signal variation of only one microwatt. The estimated generated power of a bacteria is approximately 1-4pW thus only a small number of bacteria is necessary for the experiments. Recent studies in the field of bacterial microcalorimetry have demonstrated that, in standard conditions, this method can be reproductible and can be used to detect and characterize bacterial growth (through the study of the microcalorimetric growth curve particular to a bacterial species which is called a microcalorimetric fingerprint) and offers the new information in regards to bacterial metabolism. Also, microcalorimetry can offer information about bacterial interaction with different factors in the medium (for example, antibioticsubstances, in which case an antibiogram is obtained in 4-5 hours). In conclusion, we can say that microcalorimetry is a reproducible method, which offers an interesting perspective on bacterial characterization, with great scientific potential, and there are sufficient arguments to continue studies in this field.

MicroDSC study of Staphylococcus epidermidis growth.

BACKGROUND: A microcalorimetric study was carried out using a Staphylococcus epidermidis population to determine the reproducibility of bacterial growth and the variability of the results within certain experimental parameters (temperature, bacterial concentration, sample thermal history). Reproducibility tests were performed as series of experiments within the same conditions using either freshly prepared populations or samples kept in cold storage. In both cases, the samples were obtained by serial dilution from a concentrated TSB bacterial inoculum incubated overnight. RESULTS: The results show that experiments are fairly reproducible and that specimens can be preserved at low temperatures (1 - 2°C) at least 4 days. The thermal signal variations at different temperatures and initial bacterial concentrations obey a set of rules that we identified. CONCLUSION: Our study adds to the accumulating data and confirms available results of isothermal microcalorimetry applications in microbiology and can be used to standardize this method for either research or clinical setting.