Whole blood resuscitation restores intestinal perfusion and influences gut microbiome diversity.

OBJECTIVE: Gut dysbiosis, an imbalance in the gut microbiome, occurs after trauma, which may be ameliorated with transfusion. We hypothesized that gut hypoperfusion following trauma causes dysbiosis and that whole blood (WB) resuscitation mitigates these effects. METHODS: Anesthetized rats underwent sham (S; laparotomy only, n = 6); multiple injuries (T; laparotomy, liver and skeletal muscle crush injuries, and femur fracture, n = 5); multiple injuries and 40% hemorrhage (H; n = 7); and multiple injuries, hemorrhage, and WB resuscitation (R; n = 7), which was given as 20% estimated blood volume from donor rats 1 hour posttrauma. Baseline cecal mesenteric tissue oxygen (O2) concentration was measured following laparotomy and at 1 hour and 2 hours posttrauma. Fecal samples were collected preinjury and at euthanasia (2 hours). 16S rRNA sequencing was performed on purified DNA, and diversity and phylogeny were analyzed with QIIME (Knight Lab, La Jolla, CA; Caporaso Lab, Flagstaff, AZ) using the Greengenes 16S rRNA database (operational taxonomic units; 97% similarity). α and ß diversities were estimated using observed species metrics. Permutational analysis of variance was performed for overall significance. RESULTS: In H rats, an average decline of 36% ± 3.6% was seen in the mesenteric O2 concentration at 1 hour without improvement by 2 hours postinjury, which was reversed following resuscitation at 2 hours postinjury (4.1% ± 3.1% difference from baseline). There was no change in tissue O2 concentration in the S or T rats. ß Diversity differed among groups for all measured indices except Bray-Curtis, with the spatial median of the S and R rats more similar compared with S and H rats (p < 0.05). While there was no difference in α diversity found among the groups, indices were significantly correlated with mesenteric O2 concentration. Members of the family Enterobacteriaceae were significantly enriched in only 2 hours. CONCLUSION: Mesenteric perfusion after trauma and hemorrhage is restored with WB resuscitation, which influences ß diversity of the gut microbiome. Whole blood resuscitation may also mitigate the effects of hemorrhage on intestinal dysbiosis, thereby influencing outcomes.

Microcystic Adnexal Carcinoma: A Rare, Commonly Misdiagnosed Malignancy.

Microcystic adnexal carcinoma (MAC) is a rare, malignant cutaneous neoplasm that often presents as an inconspicuous, benign appearing lesion. Patients most commonly are asymptomatic and present for improved cosmesis, however perineural invasion may result in local numbness, paresthesia or pruritus. Although distant metastasis is rare, MAC has an increased propensity for local invasion, often resulting in significant morbidity as late presentation and misdiagnosis are common. A high index of suspicion is imperative, and deep tissue biopsy with defining histologic characteristics is required for diagnosis. Mohs micrographic surgery is currently the standard of care, providing the highest possibility for long-term cure. We present a case report of a 43-year-old male Air Force U-2 pilot with a benign presentation and initial clinical misdiagnoses of MAC, who underwent Mohs micrographic surgery followed by cervicofacial flap reconstruction of a 5.5 × 3.5 cm defect. We also identify increased radiation exposure of U-2 pilots as a potential risk factor for the early development of MAC, emphasizing the importance of exploring patient risk factors while having a high index of suspicion to aid in early diagnosis.