Evaluation of using distal part of endotracheal tube samples for SARS-COV-2 diagnosis by RT-PCR

Objective: The reverse transcription-polymerase chain reaction (RT-PCR) analyses method is the most important diagnostic method in the diagnosis of SARS-CoV-2 virus infection. In this research, we aimed to investigate the positivity of SARS-CoV-2 by RT-PCR from distal part of the endotracheal tube (DPET) samples, which have not been investigated in any study yet. Materials and Methods: A total of 48 patients with a diagnosis of COVID-19 hospitalized in the intensive care unit receiving mechanical ventilation and whose conditions resulted in death or extubation were included in the study. The distal 6 cm part of the orotracheal intubation tube was removed from the patient (including the cuff). DPET samples were mixed with viral transport medium and vortexed; then, it was centrifuged at 4500g for 4 minutes. RNA isolation was performed by taking 400 µl from the supernatant and then SARS-CoV-2 RT-PCR was studied. Results: In 15 patients (31.25 %) the swab samples were PCR positive, 42 patients (87.5 %) had positive computed tomography finding and 48 patients (100 %) had positive clinical findings. Among the patients whose oropharynx (OP)/nasopharynx (NP) combined swab sample was positive for RT-PCR, the rate of RT-PCR positivity detected in DPET samples was 26.7%. While OP/NP combined swab sample was negative, DPET RT-PCR positivity rate was found to be 9.09%. Conclusions: Patients with positive DPET RT-PCR are detected when the swab is negative. These findings suggest that DPET can be used as a good lower respiratory sample without the risk of particle spread and transmission to healthcare personnel.

The New Useful High-Resolution Computed Tomography Finding for Diagnosing Fibrotic Hypersensitivity Pneumonitis: “Hexagonal Pattern”: A Single-Center Retrospective Study

Background Centrilobular nodules, ground-glass opacity (GGO), mosaic attenuation, air trapping, and three-density pattern were reported as high-resolution computed tomography (HRCT) findings characteristic of fibrotic hypersensitivity pneumonitis (HP). However, it is often difficult to differentiate fibrotic HP from idiopathic pulmonary fibrosis (IPF). In fibrotic HP, the HRCT sometimes shows tortoiseshell-like interlobular septal thickening that extends from the subpleural lesion to the inner layers. This finding is called “hexagonal pattern,” and this study is focused on the possibility that such finding is useful for differentiating fibrotic HP from IPF. Methods This study included patients with multidisciplinary discussion (MDD) diagnosis of fibrotic HP or IPF undergoing surgical lung biopsy between January 2015 and December 2017 in Kanagawa Cardiovascular and Respiratory Center. Two radiologists have evaluated the HRCT findings without clinical and pathological information. Results A total of 23 patients were diagnosed with fibrotic HP by MDD and 48 with IPF. Extensive GGO, centrilobular nodules, and hexagonal pattern were more frequent findings in fibrotic HP than in IPF. No significant difference was observed between the two groups in the presence or absence of mosaic attenuation, air trapping, or three-density pattern. In the multivariate logistic regression, the presence of extensive GGO and hexagonal pattern was associated with increased odds ratio of fibrotic HP. The sensitivity and specificity of the diagnosis of fibrotic HP in the presence of the hexagonal pattern were 69.6% and 87.5%, respectively. Conclusion Hexagonal pattern is a useful finding for differentiating fibrotic HP from IPF.

Parastomal Gallbladder Herniation as an Incidental Preoperative Computed Tomography Finding

A 65-year-old woman with a long surgical history was referred to our hospital’s Colorectal Unit for ileostomy management. The patient retained an ileostomy for almost a decade after a series of complicated operations she had undergone, which had several side effects such as electrolyte imbalances, high output, weight loss, and a parastomal hernia. Our hospital’s colorectal surgeon proposed to replace the ileostomy with a permanent sigmoidostomy and asked for an imaging evaluation of the parastomal hernia content before the surgery. A computed tomography of the abdomen was performed using our Computed Tomography Department’s 64-detector row CT scanner after oral administration of contrast media, without intravenous contrast media injection due to allergy. Concerning the parastomal ileostomal hernia, besides small bowel loops with intraluminal gastrografin, inside the parastomal hernial sac, there also was an almost rounded cystic lesion. Absence of the gallbladder at its typical position and no record of cholecystectomy raised suspicion for gallbladder projection inside the sac. Our suspicion was confirmed during the surgery. Nonexisting acute cholecystitis allowed easy reduction of the gallbladder along with the small bowel loops inside the peritoneal cavity, without proceeding to cholecystectomy at the same time. Finally, ileostomy was annulated and an end colostomy was established. Four days after the surgery, the patient was discharged from the hospital and was happy to live an almost normal life thereafter.