Clostridium difficile infection after cardiac surgery: Prevalence, morbidity, mortality, and resource utilization

ObjectiveDespite increasing efforts to prevent infection, the prevalence of hospital-associated Clostridium difficile infections (CDI) is increasing. Heightened awareness prompted this study of the prevalence and morbidity associated with CDI after cardiac surgery.MethodsA total of 22,952 patients underwent cardiac surgery at Cleveland Clinic from January 2005 to January 2011. CDI was diagnosed by enzyme immunoassay for toxins and, more recently, polymerase chain reaction (PCR) testing. Hospital outcomes and long-term survival were compared with those of the remaining population in propensity-matched groups.ResultsOne hundred forty-five patients (0.63%) tested positive for CDI at a median of 9 days postoperatively, 135 by enzyme immunoassay and 11 by PCR. Its prevalence more than doubled over the study period. Seventy-seven patients (48%) were transfers from outside hospitals. Seventy-three patients (50%) were exposed preoperatively to antibiotics and 79 (56%) to proton-pump inhibitors. Patients with CDI had more baseline comorbidities, more reoperations, and received more blood products than patients who did not have CDI. Presenting symptoms included diarrhea (107; 75%), distended abdomen (48; 34%), and abdominal pain (27; 19%). All were treated with metronidazole or vancomycin. Sixteen patients (11%) died in hospital, including 5 of 10 who developed toxic colitis; 3 of 4 undergoing total colectomy survived. Among matched patients, those with CDI had more septicemia (P < .0001), renal failure (P = .0002), reoperations (P < .0001), prolonged postoperative ventilation (P < .0001), longer hospital stay (P < .0001), and lower 3-year survival, 52% versus 64% (P = .03), than patients who did not have CDI.ConclusionsAlthough rare, the prevalence of CDI is increasing, contributing importantly to morbidity and mortality after cardiac surgery. If toxic colitis develops, mortality is high, but colectomy may be lifesaving

Intraoperative identification of esophageal sentinel lymph nodes with near-infrared fluorescence imaging

ObjectiveIn esophageal cancer, selective removal of involved lymph nodes could improve survival and limit complications from extended lymphadenectomy. Mapping with vital blue dyes or technetium Tc-99m often fails to identify intrathoracic sentinel lymph nodes. Our purpose was to develop an intraoperative method for identifying sentinel lymph nodes of the esophagus with high-sensitivity near-infrared fluorescence imaging.MethodsSix Yorkshire pigs underwent thoracotomy and received submucosal, esophageal injection of quantum dots, a novel near-infrared fluorescent lymph tracer designed for retention in sentinel lymph nodes. Six additional pigs underwent thoracotomy and received submucosal esophageal injection of CW800 conjugated to human serum albumin, another novel lymph tracer designed for uptake into distant lymph nodes. Finally, 6 pigs received submucosal injection of the fluorophore-conjugated albumin with an endoscopic needle through an esophagascope. These lymph tracers fluoresce in the near-infrared, permitting visualization of migration to sentinel lymph nodes with a custom intraoperative imaging system.ResultsInjection of the near-infrared fluorescent lymph tracers into the esophagus revealed communicating lymph nodes within 5 minutes of injection. In all 6 pigs that received quantum dot injection, only a single sentinel lymph node was identified. Among pigs that received fluorophore-conjugated albumin injection, in 5 of 12 a single sentinel lymph node was revealed, but in 7 of 12 two sentinel lymph nodes were identified. There was no dominant pattern in the appearance of the sentinel lymph nodes either cranial or caudal to the injection site.ConclusionNear-infrared fluorescence imaging of sentinel lymph nodes is a novel and reliable intraoperative technique with the power to assist with identification and resection of esophageal sentinel lymph nodes

Microbiomes of Inflammatory Thoracic Aortic Aneurysms Due to Giant Cell Arteritis and Clinically Isolated Aortitis Differ From Those of Non-Inflammatory Aneurysms

Objective: We sought to characterize microbiomes of thoracic aortas from patients with non-infectious aortitis due to giant cell arteritis (GCA) and clinically isolated aortitis (CIA) and to compare them to non-inflammatory aorta aneurysm controls. We also compared microbiomes from concurrently processed and separately reported temporal arteries (TA) and aortas. Methods: From 220 prospectively enrolled patients undergoing surgery for thoracic aorta aneurysm, 49 were selected. Inflammatory and non-inflammatory cases were selected based on ability to match for age (+/-10 years), gender, and race. Biopsies were collected under aseptic conditions and snap-frozen. Taxonomic classification of bacterial sequences was performed to the genus level and relative abundances were calculated. Microbiome differential abundances were analyzed by principal coordinates analysis. Results : Forty-nine patients with thoracic aortic aneurysms (12 CIA, 14 GCA, 23 non-inflammatory aneurysms) were enrolled. Alpha (P = 0.018) and beta (P = 0.024) diversity differed between specimens from aortitis cases and controls. There were no significant differences between CIA and GCA (P > 0.7). The largest differential abundances between non-infectious aortitis and non-inflammatory control samples includedEnterobacteriaceae, Phascolarctobacterium, Acinetobactor, Klebsiella, and Prevotella. Functional metagenomic predictions with PICRUSt revealed enrichment of oxidative phosphorylation and porphyrin metabolism pathways and downregulation of transcription factor pathways in aortitis compared to controls. Microbiomes of aortic samples differed significantly from temporal artery samples from a companion study, in both control and GCA groups (P = 0.0002). Conclusion: Thoracic aorta aneurysms, far from being sterile, contain unique microbiomes that differ from those found in temporal arteries. The aorta microbiomes are most similar between aneurysms that were associated with inflammation, GCA, and CIA, but differed from those associated with non-inflammatory etiologies. These findings are promising in that they indicate that microbes may play a role in the pathogenesis of aortitis-associated aneurysms or non-inflammatory aneurysms by promoting or protecting against inflammation. However, we cannot rule out that these changes are related to alterations in tissue substrate that favor secondary changes in microbial communities

Hippocratic Pharmaology: Investigations into the Theoretical Assumptions and Function of Drug Therapy in the Corpus Hippocraticum

The topic of this thesis is Hippocratic Pharmacology. While I intended to examine drugs and their efficacy in therapeutics, I soon realized the gravity of this undertaking: John Riddle and John Scarborough have been working on this for decades; my year\u27s work would accomplish little. Instead, I found that work needed to be done in investigating the theoretical assumptions which the Corpus authors held about drug use: how did they believe these medicines worked? What were their underlying concepts? The methodological difficulty in answering these questions is evident at once. I decided to pursue this topic in two ways: first, to examine explicit statements by various authors about pharmacology (of which there are few), and second, to look at the prescriptions themselves and work backward to the theory at their foundation. This implied some debatable assumptions, yet was feasible. The following are the results of this form of investigation