Prediction of acute lung injury assessed by chest computed tomography, oxygen saturation/fraction of inspired oxygen ratio, and serum lactate dehydrogenase in patients with COVID-19

INTRODUCTION

In treating acute hypoxemic respiratory failure (AHRF) caused by coronavirus disease 2019 (COVID-19), clinicians choose respiratory therapies such as low-flow nasal cannula oxygenation, high-flow nasal cannula oxygenation, or mechanical ventilation after assessment of the patient's condition. Chest computed tomography (CT) imaging contributes significantly to diagnosing COVID-19 pneumonia. However, the costs and potential harm to patients from radiation exposure need to be considered. This study was performed to predict the quantitative extent of COVID-19 acute lung injury using clinical indicators such as an oxygenation index and blood test results.

METHODS

We analyzed data from 192 patients with COVID-19 AHRF. Multiple logistic regression was used to determine correlations between the lung infiltration volume (LIV) and other pathophysiological or biochemical laboratory parameters.

RESULTS

Among 13 clinical parameters, we identified the oxygen saturation/fraction of inspired oxygen ratio (SF ratio) and serum lactate dehydrogenase (LD) concentration as factors associated with the LIV. In the binary classification of an LIV of ≥20 % or not and with the borderline LD = 2.2 × [SF ratio]-182.4, the accuracy, precision, diagnostic odds ratio, and area under the summary receiver operating characteristic curve were 0.828, 0.818, 23.400, and 0.870, respectively.

CONCLUSIONS

These data suggest that acute lung injury due to COVID-19 pneumonia can be estimated using the SF ratio and LD concentration without a CT scan. These findings may provide significant clinical benefit by allowing clinicians to predict acute lung injury levels using simple, minimally invasive assessment of oxygenation capacity and biochemical blood tests.

Case study observational research: inflammatory cytokines in the bronchial epithelial lining fluid of COVID-19 patients with acute hypoxemic respiratory failure

BACKGROUND

In this study, the concentrations of inflammatory cytokines were measured in the bronchial epithelial lining fluid (ELF) and plasma in patients with acute hypoxemic respiratory failure (AHRF) secondary to severe coronavirus disease 2019 (COVID-19).

METHODS

We comprehensively analyzed the concentrations of 25 cytokines in the ELF and plasma of 27 COVID-19 AHRF patients. ELF was collected using the bronchial microsampling method through an endotracheal tube just after patients were intubated for mechanical ventilation.

RESULTS

Compared with those in healthy volunteers, the concentrations of interleukin (IL)-6 (median 27.6 pmol/L), IL-8 (1045.1 pmol/L), IL-17A (0.8 pmol/L), IL-25 (1.5 pmol/L), and IL-31 (42.3 pmol/L) were significantly greater in the ELF of COVID-19 patients than in that of volunteers. The concentrations of MCP-1 and MIP-1β were significantly greater in the plasma of COVID-19 patients than in that of volunteers. The ELF/plasma ratio of IL-8 was the highest among the 25 cytokines, with a median of 737, and the ELF/plasma ratio of IL-6 (median: 218), IL-1β (202), IL-31 (169), MCP-1 (81), MIP-1β (55), and TNF-α (47) were lower.

CONCLUSIONS

The ELF concentrations of IL-6, IL-8, IL-17A, IL-25, and IL-31 were significantly increased in COVID-19 patients. Although high levels of MIP-1 and MIP-1β were also detected in the blood samples collected simultaneously with the ELF samples, the results indicated that lung inflammation was highly compartmentalized. Our study demonstrated that a comprehensive analysis of cytokines in the ELF is a feasible approach for understanding lung inflammation and systemic interactions in patients with severe pneumonia.

Effect of acute normovolemic hemodilution in patients undergoing cardiac surgery with remimazolam anesthesia

PURPOSE

The reduced effects of allogeneic transfusion with acute normovolemic hemodilution (ANH) have been reported. Harvesting a large volume of blood may maximize the effect in patients with low body weight, and the prevention of hypotension is important. Remimazolam is an anesthetic with few circulatory responses. Our aim was to evaluate whether high-volume ANH reduces the need for transfusion in cardiac patients under remimazolam anesthesia.

METHODS

In this retrospective single-center study, we enrolled cardiopulmonary bypass (CPB) patients who received remimazolam anesthesia. Changes in hemodynamic parameters were assessed. The numbers of blood transfusions and chest tube outputs were also evaluated.

RESULTS

In a total of 51 patients, ANH was performed in 27 patients with a mean body mass index of 23.2 (ANH volume: 740 ± 222 mL). No significant differences were observed in mean blood pressure during blood collection. The intraoperative amount of red blood cell (RBC) transfusion was significantly lower in the ANH group than in the control group (431 ± 678 and 1260 ± 572 mL, p < 0.001). The avoidance rates of RBC were 66.7 and 4.2%, respectively. The multivariate analysis result revealed that ANH correlated with RBC, with an odds ratio of 0.067 (95% confidence interval 0.005-0.84, p < 0.05). The postoperative bleeding at 24 h was significantly lower in the ANH group (455 ± 228 and 797 ± 535 mL, p < 0.01).

CONCLUSION

In patients undergoing CPB, ANH reduced intraoperative transfusion amount and postoperative bleeding. Hemodynamic changes during blood collection were minimal under remimazolam anesthesia and high-volume ANH was feasible.

Long Duration of Action of Tranexamic Acid After Cardiac Surgery in a Hemodialysis Patient: A Case Report

A 61-year-old woman with chronic renal dysfunction was scheduled to undergo aortic valve replacement. After a bolus of 1 g tranexamic acid (TXA), the TPA (tissue-plasminogen activator)-test result with the ClotPro system demonstrated extensive inhibition of fibrinolysis. Plasma TXA level decreased from 71 to 25 μg/dL at 6 hours postoperatively; however, no further decrease was observed. Although TXA levels dropped to 6.9 μg/dL after hemodialysis on postoperative day (PoD) 1, fibrinolytic shutdown on the TPA-test remained unchanged until PoD 2. In dialysis patients, low-dose TXA <1 g may be considered for reducing seizure and thromboembolic complications after cardiac surgery.

Choice of respiratory therapy for COVID-19 patients with acute hypoxemic respiratory failure: a retrospective case series study

Background

In the treatment of acute hypoxemic respiratory failure (AHRF) due to coronavirus 2019 (COVID-19), physicians choose respiratory management ranging from low-flow oxygen therapy to more invasive methods, depending on the severity of the patient's symptoms. Recently, the ratio of oxygen saturation (ROX) index has been proposed as a clinical indicator to support the decision for either high-flow nasal cannulation (HFNC) or mechanical ventilation (MV). However, the reported cut-off value of the ROX index ranges widely from 2.7 to 5.9. The objective of this study was to identify indices to achieve empirical physician decisions for MV initiation, providing insights to shorten the delay from HFNC to MV. We retrospectively analyzed the ROX index 6 hours after initiating HFNC and lung infiltration volume (LIV) calculated from chest computed tomography (CT) images in COVID-19 patients with AHRF.

Methods

We retrospectively analyzed the data for 59 COVID-19 patients with AHRF in our facility to determine the cut-off value of the ROX index for respiratory therapeutic decisions and the significance of radiological evaluation of pneumonia severity. The physicians chose either HFNC or MV, and the outcomes were retrospectively analyzed using the ROX index for initiating HFNC. LIV was calculated using chest CT images at admission.

Results

Among the 59 patients who required high-flow oxygen therapy with HFNC at admission, 24 were later transitioned to MV; the remaining 35 patients recovered. Four of the 24 patients in the MV group died, and the ROX index values of these patients were 9.8, 7.3, 5.4, and 3.0, respectively. These index values indicated that the ROX index of half of the patients who died was higher than the reported cut-off values of the ROX index, which range from 2.7-5.99. The cut-off value of the ROX index 6 hours after the start of HFNC, which was used to classify the management of HFNC or MV as a physician's clinical decision, was approximately 6.1. The LIV cut-off value on chest CT between HFNC and MV was 35.5%. Using both the ROX index and LIV, the cut-off classifying HFNC or MV was obtained using the equation, LIV = 4.26 × (ROX index) + 7.89. The area under the receiver operating characteristic curve, as an evaluation metric of the classification, improved to 0.94 with a sensitivity of 0.79 and specificity of 0.91 using both the ROX index and LIV.

Conclusion

Physicians' empirical decisions associated with the choice of respiratory therapy for HFNC oxygen therapy or MV can be supported by the combination of the ROX index and the LIV index calculated from chest CT images.

A comparison of the ClotPro system with rotational thromboelastometry in cardiac surgery: a prospective observational study

Viscoelastic coagulation tests have been increasingly used for hemostasis management in cardiac surgery. The ClotPro system is a novel viscoelastic device based on principles of rotational thromboelastometry. We aimed to compare ClotPro with ROTEM and plasma coagulation assays in cardiopulmonary bypass (CPB) patients. Blood samples were collected from 25 CPB patients at (1) baseline, (2) start of CPB, (3) end of CPB, and (4) end of surgery. The EX-test, IN-test, HI-test, FIB-test parameters on ClotPro were compared with corresponding ROTEM assay (EXTEM, INTEM, HEPTEM, and FIBTEM). Standard plasma coagulation assays and endogenous thrombin generation (TG) were simultaneously evaluated. Pearson correlation analyses showed moderate correlations between clotting times (CTs) (r = 0.63-0.67; p < 0.001, respectively), and strong correlations with maximal clot firmness (MCF) (r = 0.93-0.98; p < 0.001, respectively) between ClotPro and ROTEM. EX-test and IN-test MCF parameters were interchangeable with acceptable percentage errors (EX-test MCF: 7.3%, IN-test MCF: 8.3%), but FIB-test MCF (27.0%) and CT results were not (EX-test CT: 44.7%, IN-test CT: 31.4%). The correlations of PT/INR or peak TG with EX-test CTs were higher than with EXTEM CTs (PT/INR: r = 0.80 and 0.41, peak TG: 0.43 and 0.18, respectively). FIB-test MCF has strong correlation with plasma fibrinogen and factor XIII level (r = 0.84 and 0.66, respectively). ROC analyses showed that ClotPro was capable of emulating well-established ROTEM thresholds (area under curves: 0.83-1.00). ClotPro demonstrated strong correlations in MCF parameters of ROTEM in CPB patients. It may be reasonable to modify ROTEM-based transfusion algorithm pertaining to MCF parameters to establish cut-off values for ClotPro device.

[Pathological, cytological and immunohistochemical study of normal-sized ovary carcinoma syndrome]

Normal-sized ovary carcinoma syndrome(NOCS) is characterized by diffuse metastatic malignant disease of the abdominal cavity in females, with normal-sized ovaries, and no origin assigned definitively by intraoperative evaluation. To elucidate the characteristics of NOCS arising from ovarian carcinoma, we investigated the immunohistochemical reactivities of keratin, epithelial membrane antigen(EMA), vimentin, and proliferative cell nuclear antigen(PCNA) in 4 cases of ovarian carcinoma with NOCS(NOCS group), including 3 cases of serous surface papillary adenocarcinoma(SSPC) and 1 case of small ovarian primary serous papillary adenocarcinoma(SPC). These cases were compared with 3 cases of ovarian carcinoma without NOCS(non-NOCS group), including 3 cases of SPC. Cytological and histological testing of the NOCS and non-NOCS groups showed the same findings. Similar reactivities for keratin, EMA and vimentin were observed in the NOCS and non-NOCS groups. No significant change of PCNA labeling index between the groups was seen. However, clinical stage of the NOCS group was higher than that of non-NOCS group. It was hypothesized that exposure of cancer cells to peritoneal cavity in ovarian SSPC leads to the spread. In NOCS case arising from small-sized ovarian carcinoma, another factor was thought to be involved, such as genetic alteration, but it is not known.

[Immunohistochemical study of Sertoli-stromal cell tumor; comparison between the tumor arising from the gonad of a testicular feminization syndrome bearing patient and from ovaries of non-bearing patients]

The association of Sertoli-stromal cell tumor with testicular feminization syndrome (TFS) has been elaborated in the past studies. Here, we described immunohistochemical studies on Sertoli cell tumor of the gonad in a TFS patient and compare with 2 other cases of spontaneous ovarian Sertoli-stromal tumor. [Case 1] The case was a 73 year-old Japanese patient (46XY karyotype), who had had primary amenorrhea. High level of testosterone was noted in laboratory investigation (1900 ng/ml). No ambiguous morphology of external genitalia was present, but atrophy of vagina was noted. The patient was diagnosed as TFS. A left gonadal tumor was identified histologically showing well differentiated Sertoli cell tumor. The tumor cells were positive for anti-vimentin antibody but negative for anti-keratin, EMA and p53 antibodies by immunohistochemistry. The right gonad was an immature testis. [Case 2] The case was a 33 year-old female with ovarian Sertoli-Leydig cell tumor. Immunohistochemically, positive reaction for anti-keratin and p53 antibodies were observed. [Case 3] The case was a 17 year-old female with moderately differentiated Sertoli cell tumor of the ovary. The tumor cells were positive for anti-keratin, EMA and p53 antibodies by immunohistochemistry. Difference in immunohistochemical reactions between Sertoli cell tumor in TFS and Sertoli-stromal cell tumors of the ovaries was probably due to variation in the degree of gonadal development.