Toxic megacolon associated Clostridium difficile colitis

Evaluation of nutrition therapy in critically ill patients with Clostridioides difficile infection

BACKGROUND & AIMS

Nutrition therapy in the intensive care unit (ICU) is a fundamental aspect of care, but there is minimal guidance for patients with Clostridioides difficile infection (CDI) despite the potentially severe consequences of this infection on the gastrointestinal tract. The aim of this study was to assess nutrition therapy in critically ill patients with CDI compared to those without CDI for differences in nutrition delivery, need for nutrition support, and safety of nutrition therapy.

METHODS

This was a single-center, retrospective cohort study of patients admitted to the ICU from January 1, 2013, through December 31, 2022. This study compared nutrition therapy in critically ill patients who had CDI compared to a cohort who had diagnoses of other infections. Outcomes included doses of nutrition prescribed, need for nutrition support, and measures of enteral feeding tolerance.

RESULTS

A total of 66 patients were included in this study, 33 in each group. The CDI group received higher median maximum calories (24.3 kcal/kg/day) compared to the control group (21.7 kcal/kg/day) [MD 3.5, 95 % CI 0.05-7.49, p = 0.04] and higher median maximum protein doses (1.1 g/kg/day) to (0.9 g/kg/day) [MD 0.2, 95 % CI 0.04-0.38, p = 0.02]. In the CDI group, significantly more patients required nutrition support (75.8 % and 48.5 %, respectively) [OR 3.32, 95 % CI 1.16-9.84, p = 0.02], but there was no difference in the number of patients who received parenteral nutrition. Measures of enteral feeding safety and tolerance were similar between both groups.

CONCLUSION

Nutrition therapy for critically ill patients did not appear to be negatively impacted by CDI, and provision of diet or enteral nutrition therapy appeared similarly safe and tolerated compared to those without CDI.

Comprehensive review of Clostridium difficile infection: Epidemiology, diagnosis, prevention, and treatment

In recent years, nosocomial infections caused by Clostridium difficile (C. difficile) have risen, becoming a leading cause of hospital-acquired diarrhea. The global prevalence of C. difficile infection (CDI) varies across regions and populations. The diagnosis relies primarily on laboratory testing, including toxin, glutamate dehydrogenase, and nucleic acid amplification tests. Treatment strategies for CDI include antimicrobial therapy (e.g., metronidazole, vancomycin, and fidamycin), fecal transplantation, and immunotherapy (e.g., belotozumab), depending on the patient's specificity and severity. This paper reviews recent research on CDI's epidemiological characteristics, risk factors, diagnosis, treatment, and prevention, aiming to support hospitals and public health initiatives in implementing effective detection, prevention, and treatment strategies.

Fidaxomicin's Role in Overcoming Vancomycin Failure in Clostridium difficile Infections: A Case Series and Literature Review

Clostridium difficile infection (CDI), characterized by diarrheal illness with serious complications, is a common pathology in clinical practice. We present a series of five patients with CDI who underwent treatment with fidaxomicin following the failure of oral vancomycin. To our knowledge, no evidence in the literature suggests that fidaxomicin is more effective than vancomycin in treating acute infection. This paper emphasizes the importance of utilizing a large study to determine the relative effectiveness of vancomycin versus fidaxomicin in treating CDI. We also provide a literature review on CDI and management evolution.

From Hemorrhage to Diarrhea: The Comprehensive Clinical Journey of a Patient With Pseudomembranous Colitis

Pseudomembranous colitis (PC) is an inflammation of the colon primarily caused by the bacterium Clostridium difficile (C. difficile), often following antibiotic use. This case report describes the intricate clinical course of a 48-year-old male farmer with a history of chronic alcoholism, tobacco use, and seizure disorder, who presented with acute onset of left-sided weakness. CT brain revealed an intra-axial hemorrhage in the right gangliocapsular region with significant edema and midline shift. The patient's condition necessitated mechanical ventilation due to a low Glasgow Coma Scale (GCS) score. Complications ensued with the onset of ventilator-associated pneumonia (VAP) on day six, attributed to multi-drug resistant Acinetobacter baumannii, which was managed with meropenem and polymyxin. Following successful weaning from the ventilator, he experienced severe watery diarrhea, high-grade fever, and diffuse abdominal pain on day 13. Subsequent stool tests confirmed PC caused by C. difficile, characterized by diffuse colonic wall-thickening with a water target sign on contrast-enhanced CT (CECT) abdomen. Initial treatment with oral vancomycin and metronidazole was followed by symptomatic treatment. Two weeks later, the patient had a relapse of PC, presenting with multiple episodes of loose stools, which was managed with oral metronidazole alone. Colonoscopy and biopsy confirmed the relapse, showing inflamed colonic mucosa with pseudomembranes. This case highlights the importance of strict infection control, prudent antibiotic use, and close monitoring for these patients. It also suggests the potential role of fecal microbiota transplantation (FMT) for recurrent cases. The patient's recovery demonstrates the effectiveness of meticulous medical management and adherence to infection control protocols in achieving optimal outcomes.

Surgical Emergencies in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) patients are at risk for undergoing emergency surgery for fulminant disease, toxic megacolon, bowel perforation, intestinal obstruction, or uncontrolled gastrointestinal hemorrhage. Unfortunately, medical advancements have failed to significantly decrease rates of emergency surgery for IBD. It is therefore important for all acute care and colorectal surgeons to understand the unique considerations owed to this often-challenging patient population.

Clinical outcomes of clostridioides difficile infection in the very elderly

BACKGROUND

Clostridioides difficile infection (CDI) causes considerable morbidity, mortality, and economic cost. Advanced age, prolonged stay in healthcare facility, and exposure to antibiotics are leading risk factors for CDI. Data on CDI clinical outcomes in the very elderly patients are limited.

METHODS

A retrospective cohort study of patients hospitalized between 2016 and 2018 with CDI. We evaluated demographic clinical and laboratory parameters. Major clinical outcomes were evaluated including duration of hospital stay, admission to intensive care unit (ICU), in-hospital mortality, 30 days post-discharge mortality, and readmission/mortality composite outcome. We compared patients aged up to 80 years (elderly) to those of 80 years old or more (very elderly).

RESULTS

Of 196 patients included in the study, 112 (57%) were very elderly with a mean age of 86 versus 67 years in the elderly group. The duration of hospital stays, and intensive care unit admission frequency were significantly reduced in the very elderly (13 vs. 22 days p = 0.003 and 1.8% vs. 10.7% p = 0.01, respectively). No significant difference was found in the frequencies of in-hospital and in 30 days post-discharge mortality.

CONCLUSIONS

In our cohort, the duration of hospital stay seemed to be shorter in the very elderly with no increase of in-hospital and post-discharge mortality. Although admitted less frequently to ICU, the in-hospital survival of the very elderly was not adversely affected compared to the elderly, suggesting that very advanced age per se should not be a major factor to consider in determining the prognosis of a patient with CDI.

Retrospective Analysis of Clostridioides difficile Infection Rates and Outcomes in Hospitalized Patients during the COVID-19 Pandemic: A Unicenter Study in Reus, Spain

Background:Clostridioides difficile infections (CDI) vary in severity from mild diarrhea to life-threatening conditions like pseudomembranous colitis or toxic megacolon, often leading to sepsis and death. The COVID-19 pandemic prompted changes in healthcare practices, potentially affecting CDI incidence, though reported data are inconclusive. We studied factors influencing CDI incidence and outcomes at a university hospital throughout the COVID-19 pandemic years. Methods: We conducted a retrospective study on all adult hospitalized CDI cases from 1 January 2020 to 31 December 2022 in Hospital Universitari de Sant Joan in Reus. We collected demographic information, comorbid conditions, and concurrent infections. Results: While overall CDI and COVID-19 rates decreased in 2022, a notable increase in CDI infections was observed among oncological patients and those undergoing some aggressive treatments, such as colonoscopies or gastroscopies. The prevalence of comorbidities remained unmodified, and there were declines in prior gastrointestinal surgeries and proton pump inhibitor prescriptions. Factors associated with patient fatality or prolonged hospitalization included older age, cancer, chronic kidney disease, higher Charlson and McCabe indices, elevated C-reactive protein, and low albumin concentrations. Conclusions: Our study shows the evolving landscape of CDI during the COVID-19 pandemic and emphasizes the impact of delayed diagnoses and treatments exacerbated by telemedicine adoption. Identified risk factors for CDI-related mortality or prolonged hospital stays underscore the importance of targeted interventions in high-risk populations.

CSPG4-dependent cytotoxicity for C. difficile TcdB is influenced by extracellular calcium and chondroitin sulfate

TcdB is an intracellular bacterial toxin indispensable to Clostridioides difficile infections. The ability to use chondroitin sulfate proteoglycan 4 (CSPG4) as a primary cell surface receptor is evolutionarily conserved by the two major variants of TcdB. As CSPG4 does not typically undergo receptor-mediated endocytosis, we sought to identify environmental factors that stabilize interactions between TcdB and CSPG4 to promote cell binding and entry into the cytosol. Using a series of TcdB receptor-binding mutants and cell lines with various receptor expression profiles, we discovered that extracellular Ca2+ promotes receptor-specific interactions with TcdB. Specifically, TcdB exhibits preferential binding to CSPG4 in the presence of Ca2+, with the absence of Ca2+ resulting in CSPG4-independent cell surface interactions. Furthermore, Ca2+ did not enhance TcdB binding to chondroitin sulfate (CS), the sole glycosaminoglycan of CSPG4. Instead, CS was found to impact the rate of cell entry by TcdB. Collectively, results from this study indicate that Ca2+ enhances cell binding by TcdB and CS interactions contribute to subsequent steps in cell entry.

IMPORTANCE

Clostridioides difficile is a leading cause of antibiotic-associated gastrointestinal illness, and many disease pathologies are caused by the toxin TcdB. TcdB engages multiple cell surface receptors, with receptor tropisms differing among the variants of the toxin. Chondroitin sulfate proteoglycan 4 (CSPG4) is a critical receptor for multiple forms of TcdB, and insights into TcdB-CSPG4 interactions are applicable to many disease-causing strains of C. difficile. CSPG4 is modified by chondroitin sulfate (CS) and contains laminin-G repeats stabilized by Ca2+, yet the relative contributions of CS and Ca2+ to TcdB cytotoxicity have not been determined. This study demonstrates distinct roles in TcdB cell binding and cell entry for Ca2+ and CS, respectively. These effects are specific to CSPG4 and contribute to the activities of a prominent isoform of TcdB that utilizes this receptor. These findings advance an understanding of factors contributing to TcdB's mechanism of action and contribution to C. difficile disease.

Atypical Clostridium difficile Infection in a Pregnant Patient: A Case Study on Non-Diarrheal Presentation and Syndrome of Inappropriate Antidiuretic Hormone (SIADH) Complication

Clostridium difficile (C. difficile) is a Gram-positive, spore-producing bacterium that often leads to pseudomembranous colitis, typically manifesting as watery diarrhea. The risk factors for C. difficile infection (CDI) include exposure to broad-spectrum antibiotics, immunocompromised states, advanced age, usage of proton pump inhibitors (PPI), and comorbid conditions such as chronic kidney disease (CKD). This report details a case involving a 23-year-old pregnant woman who presented with symptoms of abdominal pain and constipation. She was diagnosed with a urinary tract infection (UTI) and treated with ceftriaxone. During her hospitalization, she was administered opioid pain relievers and underwent an intensive bowel regimen. Despite these measures, her constipation and abdominal discomfort persisted, and magnetic resonance imaging (MRI) of the abdomen revealed significant dilatation of the large bowel. The patient, discovered to have hyponatremia, underwent further evaluation. This revealed elevated urine osmolality and decreased blood plasma osmolality, indicative of a syndrome of inappropriate antidiuretic hormone secretion (SIADH). The patient received treatment with hypertonic saline. Later in her hospital stay, she tested positive for CDI through stool analysis and was treated with oral vancomycin. This case underscores the importance of considering CDI as a differential diagnosis in cases of ileus, abdominal pain, and constipation, especially in patients with notable risk factors for CDI. It highlights that the presence of diarrhea or watery bowel movements is not a necessary symptom for CDI testing.

Defined microbial communities and their soluble products protect mice from Clostridioides difficile infection

Clostridioides difficile is the leading cause of antibiotic-associated infectious diarrhea. The development of C.difficile infection is tied to perturbations of the bacterial community in the gastrointestinal tract, called the gastrointestinal microbiota. Repairing the gastrointestinal microbiota by introducing lab-designed bacterial communities, or defined microbial communities, has recently shown promise as therapeutics against C.difficile infection, however, the mechanisms of action of defined microbial communities remain unclear. Using an antibiotic- C.difficile mouse model, we report the ability of an 18-member community and a refined 4-member community to protect mice from two ribotypes of C.difficile (CD027, CD078; p < 0.05). Furthermore, bacteria-free supernatant delivered orally to mice from the 4-member community proteolyzed C.difficile toxins in vitro and protected mice from C.difficile infection in vivo (p < 0.05). This study demonstrates that bacteria-free supernatant is sufficient to protect mice from C.difficile; and could be further explored as a therapeutic strategy against C.difficile infection.

Clostridioides Difficile: A Concise Review of Best Practices and Updates

Clostridioides difficile infection (CDI) is one of the most common and severe nosocomial infections worldwide. It can also affect healthy individuals in the community. The incidence of CDI has been on the rise globally for the past decade, necessitating a proactive approach to combat its spread; new strategies are being developed to enhance diagnostic accuracy and optimize treatment outcomes. Implementing the 2-step testing has increased diagnostic specificity, reducing the usage of CD-specific antibiotics with no concomitant increase in surgical complication rates. In 2021, the Infectious Diseases Society of America/Society for Healthcare Epidemiology of America (IDSA/SHEA) shifted its preference for initial treatment to fidaxomicin over vancomycin and metronidazole due to its lower recurrence rate. It also prioritized fidaxomicin for the treatment of recurrent CDI. There are new developments on the frontiers of fecal microbiota therapies, with RBX2660 and SER-109 approved recently by the FDA for prevention, with other microbiome-based therapies in various development and clinical trials. This review offers providers an updated and practical guide for CDI management.

Toxic Megacolon: A Sequelae of Clostridioides difficile Infection in a Case of Necrotizing Fasciitis

Necrotizing fasciitis is an illness that ascends quickly and affects the fascia, subcutaneous tissues, and deeper skin layers. To combat this infection, strong antibiotics are used along with prompt debridement. Frequent usage of such drugs is connected to antibiotic-associated diarrhea and colonic illnesses like colitis. High-spectrum antibiotic usage over an extended period of time can alter the gut microbiota, which promotes the growth of commensal bacteria including Staphylococcus aureus and Clostridioides difficile (previously known as Clostridium difficile) resulting in complications such as toxic megacolon. C. difficile infection can result in extreme inflammation and colon dilatation leading to toxic megacolon. In order to effectively treat necrotizing fasciitis, a timely diagnosis and vigorous management are essential; failing of which may have fatal consequences such as sepsis and even mortality. We present a case of a 56-year-old male, suffering from necrotizing fasciitis of the left lower limb which further complicated to toxic megacolon and caused mortality of the patient. Timely presentation and early diagnosis can be helpful in better prognosis, which in the context of this case was delayed; had the patient presented to the hospital earlier, there were chances of preventing mortality.

[Modern concept of differential diagnosis of colitis: from G.F. Lang to the present day. A review]

The aim of the article is to improve the differential diagnosis of specific and nonspecific inflammatory bowel diseases. In Russia, this scientific direction is associated with the name of G.F. Lang, who performed in 1901-1902 the study "On ulcerative inflammation of the large intestine caused by balantidiasis". The etiology of specific colitis is associated with infection with parasites, bacteria and viruses that cause inflammation of the intestinal wall, diarrhea, often with an admixture of mucus, pus and blood. Specific colitis (SC) may be accompanied by fever, abdominal pain, and tenesmus. Bacterial colitis is commonly caused by Salmonella, Shigella, Escherichia coli, Clostridium difficile, Campylobacter jejuni, Yersinia enterocolitica, and Mycobacterium tuberculosis. Viral colitis is caused by rotavirus, adenovirus, cytomegalovirus, and norovirus. Parasitic colitis can be caused by Entamoeba histolytica and balantidia. In gay people, SC can cause sexually transmitted infections: Neisseria gonorrhoeae, Chlamydia trachomatis, and treponema pallidum, affecting the rectum. Stool microscopy, culture, and endoscopy are used to establish the diagnosis. Stool culture helps in the diagnosis of bacterial colitis in 50% of patients, and endoscopic studies reveal only nonspecific pathological changes. Differential diagnosis of SC should be carried out with immune-inflammatory bowel diseases (ulcerative colitis, Crohn's disease, undifferentiated colitis), radiation colitis and other iatrogenic bowel lesions. The principles of diagnosis and therapy of inflammatory bowel diseases associated with various etiological.

Clostridioides difficile infection leading to fulminant colitis with toxic megacolon

Clostridioidesdifficile infection (CDI) is the culprit of millions of nosocomial infections in the United States. Programs that successfully decrease its incidence, therefore, render cost savings for the healthcare system. Toxic megacolon and perforation are two of the most significant complications with increased mortality rates. We report a 23-year-old nursing home resident hospitalized for fever, cough, and green sputum. After 3 days of antibiotic therapy, he developed abdominal distension, diarrhea, and vomiting and underwent a total colectomy. The colon was dilated to a maximum of 11 cm with markedly edematous mucosa and yellow pseudomembranes. Qualitative PCR of the stool detected Clostridioides difficile toxin B gene. While there is no consensus for the required interval between antibiotic treatment and CDI, this presentation 3 days after starting the antibiotic therapy is earlier than most proposed ranges.

Nitro-Group-Containing Thiopeptide Derivatives as Promising Agents to Target Clostridioides difficile

The US Centers for Disease Control and Prevention (CDC) lists Clostridioides difficile as an urgent bacterial threat. Yet, only two drugs, vancomycin and fidaxomicin, are approved by the FDA for the treatment of C. difficile infections as of this writing, while the global pipeline of new drugs is sparse at best. Thus, there is a clear and urgent need for new antibiotics against that organism. Herein, we disclose that AJ-024, a nitroimidazole derivative of a 26-membered thiopeptide, is a promising anti-C. difficile lead compound. Despite their unique mode of action, thiopeptides remain largely unexploited as anti-infective agents. AJ-024 combines potent in vitro activity against various strains of C. difficile with a noteworthy safety profile and desirable pharmacokinetic properties. Its time-kill kinetics against a hypervirulent C. difficile ribotype 027 and in vivo (mouse) efficacy compare favorably to vancomycin, and they define AJ-024 as a valuable platform for the development of new anti-C. difficile antibiotics.

Fecal Microbial Transplantation in Critically Ill Patients-Structured Review and Perspectives

The human gut microbiota consists of bacteria, archaea, fungi, and viruses. It is a dynamic ecosystem shaped by several factors that play an essential role in both healthy and diseased states of humans. A disturbance of the gut microbiota, also termed "dysbiosis", is associated with increased host susceptibility to a range of diseases. Because of splanchnic ischemia, exposure to antibiotics, and/or the underlying disease, critically ill patients loose 90% of the commensal organisms in their gut within hours after the insult. This is followed by a rapid overgrowth of potentially pathogenic and pro-inflammatory bacteria that alter metabolic, immune, and even neurocognitive functions and that turn the gut into the driver of systemic inflammation and multiorgan failure. Indeed, restoring healthy microbiota by means of fecal microbiota transplantation (FMT) in the critically ill is an attractive and plausible concept in intensive care. Nonetheless, available data from controlled studies are limited to probiotics and FMT for severe C. difficile infection or severe inflammatory bowel disease. Case series and observational trials have generated hypotheses that FMT might be feasible and safe in immunocompromised patients, refractory sepsis, or severe antibiotic-associated diarrhea in ICU. There is a burning need to test these hypotheses in randomized controlled trials powered for the determination of patient-centered outcomes.

CT features of toxic megacolon: A systematic review

INTRODUCTION

Toxic megacolon is a rare but life-threatening condition. Diagnosis is made when both systemic toxicity and an enlarged colon are present. We undertook a systematic review of the literature to provide a list of toxic megacolon findings on computed tomography (CT) imaging along with the prevalence rate for each finding.

METHODS

PubMed, Embase, and Cochrane library were searched. After eligibility screening and quality assessment, the reported CT findings of toxic megacolon with their respective prevalence rates were extracted from the included studies. Pooled prevalence rates were calculated for each finding using random-effects model and inverse variance method. I2 statistics were used to estimate the heterogeneity. All statistical analyses were performed using R software. P-values less than 0.05 were considered significant.

RESULTS

Database search yielded a total of 122 records. Only 2 of these studies were finally selected following two-step eligibility screening. Most common CT features of toxic megacolon and their pooled prevalence rates [95% CI] were: colonic distension (reported in 100% of patients), abnormal haustration 96% [0.75-0.99], peri-colonic fat stranding 87% [0.29-0.99], nodular pseudo polyps 76% [0.52-0.91], multilayered appearance of colonic wall 58% [0.38-0.76], and ascites 57% [0.21-0.87]. Other reported CT features: colonic wall thickening, pleural effusion, accordion sign, small bowel/gastric distension, and segmental colonic wall thinning.

CONCLUSION

and implication for practice: Colonic distension can be accompanied by 10 other findings in CT images of patients with toxic megacolon. Although these findings are not specific, toxic megacolon should be included in the list of differential diagnoses when these findings are present.

Randomized Controlled Trial of Oral Vancomycin Treatment in Clostridioides difficile-Colonized Patients

Clostridioides difficile infection (CDI) is most commonly diagnosed using nucleic acid amplification tests (NAAT); the low positive predictive value of these assays results in patients colonized with C. difficile unnecessarily receiving CDI treatment antibiotics. The risks and benefits of antibiotic treatment in individuals with such cases are unknown. Fecal samples of NAAT-positive, toxin enzyme immunoassay (EIA)-negative patients were collected before, during, and after randomization to vancomycin (n = 8) or placebo (n = 7). C. difficile and antibiotic-resistant organisms (AROs) were selectively cultured from fecal and environmental samples. Shotgun metagenomics and comparative isolate genomics were used to understand the impact of oral vancomycin on the microbiome and environmental contamination. Overall, 80% of placebo patients and 71% of vancomycin patients were colonized with C. difficile posttreatment. One person randomized to placebo subsequently received treatment for CDI. In the vancomycin-treated group, beta-diversity (P = 0.0059) and macrolide-lincosamide-streptogramin (MLS) resistance genes (P = 0.037) increased after treatment; C. difficile and vancomycin-resistant enterococci (VRE) environmental contamination was found in 53% of patients and 26% of patients, respectively. We found that vancomycin alters the gut microbiota, does not permanently clear C. difficile, and is associated with VRE colonization/environmental contamination. (This study has been registered at ClinicalTrials.gov under registration no. NCT03388268.)IMPORTANCE A gold standard diagnostic for Clostridioides difficile infection (CDI) does not exist. An area of controversy is how to manage patients whose stool tests positive by nucleic acid amplification tests but negative by toxin enzyme immunoassay. Existing data suggest most of these patients do not have CDI, but most are treated with oral vancomycin. Potential benefits to treatment include a decreased risk for adverse outcomes if the patient does have CDI and the potential to decrease C. difficile shedding/transmission. However, oral vancomycin perturbs the intestinal microbiota and promotes antibiotic-resistant organism colonization/transmission. We conducted a double-blinded randomized controlled trial to assess the risk-benefit of oral vancomycin treatment in this population. Oral vancomycin did not result in long-term clearance of C. difficile, perturbed the microbiota, and was associated with colonization/shedding of vancomycin-resistant enterococci. This work underscores the need to better understand this population of patients in the context of C. difficile/ARO-related outcomes and transmission.

Evaluation and management of the surgical abdomen

PURPOSE OF REVIEW

The aim of this study was to describe important features of clinical examination for the surgical abdomen, relevant investigations, and acute management of common surgical problems in the critically ill.

RECENT FINDINGS

Lactate remains a relatively nonspecific marker of gut ischemia. Dual energy computed tomography (DECT) scan can improve diagnosis of bowel ischemia. Further evidence supports intravenous contrast during CT scan in critically ill patients with acute kidney injury. Outcomes for acute mesenteric ischemia have failed to improve over time; however, increasing use of endovascular approaches, including catheter-directed thrombolysis, may decrease need for laparotomy in the appropriate patient. Nonocclusive mesenteric ischemia remains a challenging diagnostic and management dilemma. Acalculous cholecystitis is managed with a percutaneous cholecystostomy and is unlikely to require interval cholecystectomy. Surgeon comfort with intervention based on point-of-care ultrasound for biliary disease is variable. Mortality for toxic megacolon is decreasing.

SUMMARY

Physical examination remains an integral part of the evaluation of the surgical abdomen. Interpreting laboratory investigations in context and appropriate imaging improves diagnostic ability; intravenous contrast should not be withheld for critically ill patients with acute kidney injury. Surgical intervention should not be delayed for the patient in extremis. The intensivist and surgeon should remain in close communication to optimize care.

Utilizing a real-time discussion approach to improve the appropriateness of Clostridioides difficile testing and the potential unintended consequences of this strategy

We report electronic medical record interventions to reduce Clostridioides difficile testing risk 'alert fatigue.' We used a behavioral approach to diagnostic stewardship and observed a decrease in the number of tests ordered of ~4.5 per month (P < .0001). Although the number of inappropriate tests decreased during the study period, delayed testing increased.

Investigating the transient and persistent effects of heat on Clostridium difficile spores

Purpose. Clostridium difficile spores are extremely resilient to high temperatures. Sublethal temperatures are associated with the 'reactivation' of dormant spores, and are utilized to maximize C. difficile spore recovery. Spore eradication is of vital importance to the food industry. The current study seeks to elucidate the transient and persisting effects of heating C. difficile spores at various temperatures.Methods. Spores of five C. difficile strains of different ribotypes (001, 015, 020, 027 and 078) were heated at 50, 60 and 70-80 °C for 60 min in phosphate-buffered saline (PBS) and enumerated at 0, 15, 30, 45 and 60 min. GInaFiT was used to model the kinetics of spore inactivation. In subsequent experiments, spores were transferred to enriched brain heart infusion (BHI) broths after 10 min of 80 °C heat treatment in PBS; samples were enumerated at 90 min and 24 h.Results. The spores of all strains demonstrated log-linear inactivation with tailing when heated for 60 min at 80 °C [(x̄=7.54±0.04 log₁₀ vs 4.72±0.09 log₁₀ colony-forming units (c.f.u.) ml^{- 1}; P<0.001]. At 70 °C, all strains except 078 exhibited substantial decline in recovery over 60 min. Interestingly, 50 °C heat treatment had an inhibitory effect on 078 spore recovery at 0 vs 60 min (7.61±0.06 log₁₀ c.f.u. ml^{- 1} vs 6.13±0.05 log₁₀ c.f.u. ml^{- 1}; P<0.001). Heating at 70/80 °C inhibited the initial germination and outgrowth of both newly produced and aged spores in enriched broths. This inhibition appeared to be transient; after 24 h vegetative counts were higher in heat-treated vs non-heat-treated spores (x̄=7.65±0.04 log₁₀ c.f.u. ml^{- 1} vs 6.79±0.06 log₁₀ c.f.u. ml^{- 1}; P<0.001).Conclusions. The 078 spores were more resistant to the inhibitory effects of higher temperatures. Heat initially inhibits spore germination, but the subsequent outgrowth of vegetative populations accelerates after the initial inhibitory period.

Clostridium difficile colitis: CT findings and differential diagnosis

Clostridium difficile infection (CDI) is a severe and potentially deadly infectious colitis whose incidence is dramatically increasing in the last decades, with more virulent strains. CDI should be suspected in case of unexplained diarrhea and abdominal pain in patients with a recent history of antibiotic use and healthcare exposures; diagnosis is based on a combination of clinical and laboratory findings with demonstration of C. difficile toxins by stool test. The advantages of contrast-enhanced computed tomography (CECT) are the noninvasiveness and the ability to evaluate both the colonic wall and the adjacent soft tissues. Considerable overlap exists between the CECT findings of CDI and those of colitis of other origins, such as typhlitis, ischemic colitis, graft-versus-host disease, radiation colitis and inflammatory bowel diseases; however, some features may help distinguish between these conditions. This paper provides a comprehensive overview of the imaging features of Clostridium difficile colitis and its mimics, with a view to assist the radiologist in reaching the correct diagnosis.

Laboratory-developed test for detection of acute Clostridium difficile infections with the capacity for quantitative sample normalization

We describe a laboratory-developed test intended for the detection of acute Clostridium difficile infections (CDI) with the capacity for quantitative sample normalization. The test is based on the detection of the tcdB gene. However, this biomarker is also present among people without symptoms, implying that individuals with diarrhea, not caused by C. difficile may nonetheless test positive. Therefore, clinical diagnosis based on this format of testing can be challenging. In order to improve diagnostic assays capability, tcdB-based quantification methods were suggested as a potential solution, however they did not increase clinical specificity. We report methodology for a dual biomarker monitoring (total bacterial load and tcdB assay), allowing for the calculation of the relative presence of tcdB in the total bacterial population in the tested samples. We believe that this approach is clinically relevant to current assays and can improve CDI testing algorithms.

Evidence of transmission of Clostridium difficile in asymptomatic patients following admission screening in a tertiary care hospital

BACKGROUND

Clostridium difficile (CD) is the leading cause of infectious health-care associated diarrhea. However, little is known regarding CD carriage and transmission amongst asymptomatic colonizers. We evaluated carriage, characterized strains and examined epidemiologic linkages in asymptomatic colonized CD patients.

METHODS

Rectal swabs from asymptomatic patients admitted to the general medicine ward from April 1-June 30 2012 were collected. PCR-confirmed CD colonies were ribotyped and characterized by Modified-Multi Locus Variable Number Tandem Repeat Analysis (MMLVA).

RESULTS

1549-swabs were collected from 474-patients. Overall, 50/474(10.6%) were CD PCR-positive, 24/50 were colonized at admission, while 26/50 were first identified > = 72 hours after admission. Amongst the 50 CD PCR-positive patients, 90% were asymptomatically colonized and 80% of individuals carried toxigenic CD-strains, including ribotype-027 (5/45:11%). MMLVA revealed five-clusters involving 15-patients harboring toxigenic (4/5) and non-toxigenic CD strains (1/5). In two clusters, patients were CD positive on admission while in the other three clusters involving 10 patients, we observed CD transmission from asymptomatically colonized patients to 8 previously CD-negative patients.

CONCLUSIONS

We identified increasing rates of colonization during admission to medical wards. MMLVA typing effectively discriminated between strains and suggests that 20% of patients with CD colonization acquired their strain(s) from asymptomatically colonized individuals in hospital.

Effectiveness of a Two-Step Testing Algorithm for Reliable and Cost-Effective Detection of Clostridium difficile Infection in a Tertiary Care Hospital in Saudi Arabia

The aim of this study was to evaluate the effectiveness of a two-step algorithm for the detection of Clostridium difficile infection. Setting and Design: A two-step testing algorithm was evaluated for testing stool samples from patients suspected of Clostridium difficile infection (CDI). A total of 103 stool specimens were tested using the C. diff Quik Chek Complete enzyme immunoassay (EIA) test and the Xpert C. difficile PCR test. A two-step algorithm was implemented, and data from 3518 patient samples tested during a two-year period after implementation were analyzed to evaluate the effectiveness. The sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of the Quik Chek Complete EIA test were calculated using the Xpert C. difficile PCR test as a reference method. The sensitivity, specificity, PPV, and NPV of the Quik Chek Complete EIA test for C. difficile toxin were 46.7%, 100%, 100%, and 91%, respectively. The two-step algorithm, which combined the Quik Chek Complete EIA with Xpert C. difficile PCR, improved the sensitivity and also provided rapid detection. When algorithm-based testing was performed daily, there was a 66% reduction in turnaround time compared to batch testing using a lengthy ELISA procedure. Postimplementation data analysis showed that almost 89% of the samples could be reported immediately by initial screening with Quik Chek Complete EIA. Only 11% of the samples gave discrepant results and required PCR confirmation. According to our results, the two-step algorithm is an effective tool for the rapid and reliable detection of toxigenic C. difficile from stool samples.

The Differential Diagnosis of Acute Colitis: Clues to a Specific Diagnosis

This review describes a systematic approach to the interpretation of colonic biopsy specimens of patients with acute colitis. Five main histologic patterns are discussed: acute colitis, focal active colitis, pseudomembranous colitis, hemorrhagic colitis, and ischemic colitis. For each pattern, the most common etiologic associations and their differential diagnoses are presented. Strategies based on histologic analysis and clinical considerations to differentiate acute from chronic colitides are discussed.

Investigating the effect of supplementation on Clostridioides (Clostridium) difficile spore recovery in two solid agars

BACKGROUND

A variety of supplemented solid media are used within Clostridium difficile research to optimally recover spores. Our study sought to investigate different media and additives, providing a method of optimised C. difficile spore recovery. Additionally, due to the results observed in the initial experiments, the inhibitory effects of three amino acids (glycine, l-histidine &l-phenylalanine) on C. difficile spore outgrowth were investigated.

METHODS

Spores of five C. difficile strains (PCR ribotypes 001,015,020,027,078) were recovered on two commonly used solid media (BHI & CCEY, or cycloserine-cefoxitin egg yolk) supplemented with various concentrations of germinants (taurocholate, glycine & lysozyme). Agar-incorporation minimum inhibitory concentration (MIC) testing was carried out for glycine and taurocholate on vegetative cells and spores of all five strains. Additionally a BHI broth microassay method was utilised to test the growth of C. difficile in the presence of increasing concentrations (0,1,2,3,4%) of three amino acids (glycine,l-histidine,l-phenyalanine).

RESULTS

CCEY agar alone and BHI supplemented with taurocholate (0.1/1%) provided optimal recovery for C. difficile spores. Glycine was inhibitory to spore recovery at higher concentrations, although these varied between the two media used. In agar-incorporated MIC testing, glycine concentrations higher than 2% (20 g/L) were inhibitory to both C. difficile spore and vegetative cell growth versus the control (mean absorbance = 0.33 ± 0.02 vs 0.12 ± 0.01) (P < 0.001). This indicates a potential mechanism whereby glycine interferes with vegetative cell growth. Further microbroth testing provided evidence of inhibition by two amino acids other than glycine, l-histidine and l-phenylalanine.

CONCLUSIONS

We provide two media for optimal recovery of C. difficile spores (CCEY alone and BHI supplemented with 0.1/1% taurocholate). CCEY is preferred for isolation from faecal samples. For pure cultures, either CCEY or supplemented BHI agar are appropriate. The inhibitory nature of three amino acids (glycine,l-histidine,l-phenylalanine) to C. difficile vegetative cell proliferation is also highlighted.

Current knowledge on the laboratory diagnosis of Clostridium difficile infection

Clostridium difficile (C. difficile) is a spore-forming, toxin-producing, gram-positive anaerobic bacterium that is the principal etiologic agent of antibiotic-associated diarrhea. Infection with C. difficile (CDI) is characterized by diarrhea in clinical syndromes that vary from self-limited to mild or severe. Since its initial recognition as the causative agent of pseudomembranous colitis, C. difficile has spread around the world. CDI is one of the most common healthcare-associated infections and a significant cause of morbidity and mortality among older adult hospitalized patients. Due to extensive antibiotic usage, the number of CDIs has increased. Diagnosis of CDI is often difficult and has a substantial impact on the management of patients with the disease, mainly with regards to antibiotic management. The diagnosis of CDI is primarily based on the clinical signs and symptoms and is only confirmed by laboratory testing. Despite the high burden of CDI and the increasing interest in the disease, episodes of CDI are often misdiagnosed. The reasons for misdiagnosis are the lack of clinical suspicion or the use of inappropriate tests. The proper diagnosis of CDI reduces transmission, prevents inadequate or unnecessary treatments, and assures best antibiotic treatment. We review the options for the laboratory diagnosis of CDI within the settings of the most accepted guidelines for CDI diagnosis, treatment, and prevention of CDI.

Toxic Megacolon - A Three Case Presentation

Introduction

Toxic megacolon is a life-threatening disease and is one of the most serious complications of Clostridium difficile infection (CDI), usually needing prompt surgical intervention. Early diagnosis and adequate medical treatment are mandatory.

Cases presentation

In the last two years, three Caucasian female patients have been diagnosed with toxic megacolon and treated in the Clinical Infectious Diseases Hospital, Constanta. All patients had been hospitalized for nonrelated conditions. The first patient was in chemotherapy for non-Hodgkin’s lymphoma, the second patient had undergone surgery for colon cancer, and the third patient had surgery for disc herniation. In all cases the toxin test (A+B) was positive and ribotype 027 was present. Abdominal CT examination, both native and after intravenous contrast, showed significant colon dilation, with marked thickening of the wall. Resolution of the condition did not occur using the standard treatment of metronidazole and oral vancomycin, therefore the therapy was altered in two cases using intracolonic administration of vancomycin and intravenous tigecycline.

Conclusions

In these three cases of CDI, the risk factors for severe evolution were: concurrent malignancy, renal failure, obesity, and immune deficiencies. Ribotype 027, a marker for a virulent strain of CD, was found in all three cases complicated by toxic megacolon. The intracolonic administration of vancomycin, and intravenous tigecycline was successful when prior standard therapy had failed, and surgery was avoided.

Clostridium Difficile Infection Complicated By Toxic Megacolon In Immunocompetent Patient

Toxic megacolon can be a form of severe clinical course of the infection with Clostridium difficile (ICD), life-threatening, requiring a particular course of treatment. Infection with Clostridium difficile in the Galati Infectious Disease Hospital presents rising number of cases, namely 172 cases in 2014, 271 cases in 2015 and 301 cases in 2016 with clinical evolutions with different severity degrees, including toxic megacolon and death. Among 744 patients with ICD in our clinic, since 1st January 2014 to 31 December 2016. The frequency of toxic megacolon (TM) was 0,537%, so: 3 toxic megacolon cases with favorable evolution with treatment with vancomycin and metronidazole and just one case whose evolution was aggravated under this therapy and evolved favorably under treatment with tigecycline. The work presents this last case of ICD occurred in a 69 years old, immunocompetent man with unknown concomitant chronic diseases which undergoes surgery for bilateral inguinal hernia and receives antibiotherapy with cephalosporin IIIrd generation during surgery and after 7 days develops medium degree ICD with score Atlas 3 and receives therapy with oral vancomycin. He presents clinical aggravation during this therapy with the occurrence of colon dilatation, ascites and right pleurisy at ultrasound and therapy associated with metronidazole is decided. Clinical aggravation continues in this combined therapy with defining the clinical, colonoscopy and tomography criteria for TM and is decided surgical monitoring and replacing antibiotherapy with tigecycline. Evolution is favorable with tigecycline without surgical intervention.

Point-Counterpoint: What Is the Optimal Approach for Detection of Clostridium difficile Infection?

INTRODUCTIONIn 2010, we published an initial Point-Counterpoint on the laboratory diagnosis of Clostridium difficile infection (CDI). At that time, nucleic acid amplification tests (NAATs) were just becoming commercially available, and the idea of algorithmic approaches to CDI was being explored. Now, there are numerous NAATs in the marketplace, and based on recent proficiency test surveys, they have become the predominant method used for CDI diagnosis in the United States. At the same time, there is a body of literature that suggests that NAATs lack clinical specificity and thus inflate CDI rates. Hospital administrators are taking note of institutional CDI rates because they are publicly reported. They have become an important metric impacting hospital safety ratings and value-based purchasing; hospitals may have millions of dollars of reimbursement at risk. In this Point-Counterpoint using a frequently asked question approach, Ferric Fang of the University of Washington, who has been a consistent advocate for a NAAT-only approach for CDI diagnosis, will discuss the value of a NAAT-only approach, while Christopher Polage of the University of California Davis and Mark Wilcox of Leeds University, Leeds, United Kingdom, each of whom has recently written important articles on the value of toxin detection in the diagnosis, will discuss the impact of toxin detection in CDI diagnosis.

Exam 4 Questions

A 73-year-old male with a history of hypertension and hyperlipidemia is currently in the stroke unit after suffering a right middle cerebral artery infarct. His symptoms started 2 h prior to arrival at the hospital, and tPA was administered. The patient is plegic on the left side and with mild dysarthria, but is otherwise neurologically intact. His labwork is within normal limits. Which of the following describes the optimal deep venous thrombosis (DVT) prophylaxis regimen for this patient?A.

Wait 6 h post tPA, then administer unfractionated heparin (UFH) along with intermittent pneumatic compression (IPC)

B.

Wait 24 h post tPA, then administer UFH along with IPC

C.

Wait 6 h post tPA, then administer low molecular weight heparin (LMWH) along with IPC

D.

Wait 24 h post tPA, then administer LMWH along with IPC

E.

IPC only for the first 72 h, then LMWH or UFH after obtaining follow-up imaging

All of the following causes of acute encephalitis have the matching characteristic radiological features except:A.

Autoimmune limbic encephalitis: T2/FLAIR hyperintensity in the mesial temporal lobes

B.

Cytomegalovirus: T2/FLAIR hyperintensity in the subependymal white matter

C.

JC virus: T2/FLAIR hyperintensity in the parieto-occipital lobes and corpus callosum

D.

Herpes simplex virus type 1: restricted diffusion in frontal/temporal lobes and insular cortex

E.

Varicella zoster: T2/FLAIR hyperintensity in the brainstem

Which of the following categorizations is most accurate regarding acute respiratory distress syndrome (ARDS) in the setting of subarachnoid hemorrhage (SAH)?A.

Non-neurogenic, non-cardiogenic

B.

Neurogenic, non-cardiogenic

C.

Neurogenic, cardiogenic

D.

Non-neurogenic, cardiogenic

E.

None of the above accurately reflect ARDS in SAH

A 52-year-old female is admitted to the ICU with a Hunt-Hess 1, modified Fisher 2 subarachnoid hemorrhage. Her past medical history is significant for hypertension, diabetes mellitus, and chronic renal insufficiency. She undergoes craniotomy for surgical clipping of an anterior cerebral artery aneurysm, and does not experience any additional complications. Two weeks later, she begins complaining of left calf pain, and a lower extremity sonogram demonstrated a proximal deep venous thrombosis (DVT). The patient weighs 60 kg. Her laboratory values are as follows: sodium 142 mEq/L, potassium 3.4 mEq/L, carbon dioxide 18 mEq/L, blood urea nitrogen (BUN) 70 mg/dL, and serum creatinine 2.5 mg/dL. What would be the optimal treatment for this patient’s proximal DVT?A.

Unfractionated heparin infusion for at least 5 days concomitantly with warfarin therapy

B.

Low molecular weight heparin 60 mg twice a day for at least 5 days concomitantly with warfarin therapy

C.

Fondaparinux 7.5 mg daily for 5 days followed by warfarin therapy

D.

Apixaban 10 mg twice daily for 7 days followed by 5 mg twice daily

E.

Rivaroxaban 15 mg twice daily for 21 days followed by 20 mg once daily

All of the following are currently implicated in uremic encephalopathy except:A.

Derangements in cerebral metabolism

B.

Alterations in the blood-brain barrier

C.

Accumulation of circulating toxins

D.

Imbalance of endogenous neurotransmitters

E.

Recurrent lobar hemorrhages

A 70-year-old female is hospitalized with a recent ischemic infarct. As part of stroke core measures, you obtain a hemoglobin A1c of 10.0. What is an approximate estimation of this patient’s average blood glucose level over the last several months?A.

70 mg/dL

B.

100 mg/dL

C.

130 mg/dL

D.

190 mg/dL

E.

240 mg/dL

A 28-year-old female with no known past medical history is in the ICU in status epilepticus, with anti-N-methyl D-aspartate (NMDA) receptor antibodies isolated in the cerebrospinal fluid. Which of the following is most likely to identify the root cause of her illness?A.

Transvaginal ultrasound

B.

Contrast-enhanced CT of the chest

C.

Contrast-enhanced CT of the brain

D.

Virtual colonography

E.

Thorough examination of the skin, particularly in sun-exposed areas

A 17-year-old male with no significant past medical history collapses during a high school football game, and goes into cardiac arrest. He did not have any complaints earlier in the day. The patient is brought to a nearby hospital, where is he resuscitated, intubated, and transferred to the ICU for further management. The patient is currently undergoing therapeutic hypothermia, and a work-up is underway to determine the cause of his sudden collapse. Which of the following is the most likely diagnosis?A.

Rupture of a previously undiagnosed cerebral aneurysm

B.

Hypertrophic cardiomyopathy

C.

Commotio cordis

D.

Severe hyponatremia and cerebral edema

E.

Brugada syndrome

A 31-year-old female at 38 weeks gestation is currently hospitalized for the treatment of preeclampsia. Due to her medical condition, her obstetrician is currently considering induced labor. At which point will this patient no longer be at risk for developing frank seizure activity as a result of her condition?A.

48 h postpartum

B.

1 week after delivery

C.

2 weeks after delivery

D.

4 weeks after delivery

E.

6 weeks after delivery

A 38-year-old male with no prior medical history presents to the emergency department with fever and severe headaches for several days. A CT scan of the brain is unremarkable, and the results of a lumbar puncture are pending. What is the most appropriate empiric antimicrobial regimen at this time?A.

Cefazolin and vancomycin

B.

Ceftriaxone and vancomycin

C.

Ceftriaxone, vancomycin and ampicillin

D.

Piperacillin/tazobactam and vancomycin

E.

Meropenem and vancomycin

The majority of intramedullary spinal cord neoplasms are:A.

Astrocytomas

B.

Meningiomas

C.

Metastatic lesions

D.

Ependymomas

E.

Hemangioblastomas

Which of the following derived parameter formulas is correct?A.

Cardiac index = cardiac output x body surface area

B.

Stroke volume = cardiac output/heart rate

C.

Systemic vascular resistance = 80 × (mean arterial pressure/cardiac output)

D.

Pulmonary vascular resistance = 80 × (mean pulmonary artery pressure/cardiac output)

E.

All of the above are correct

A 23-year-old female marathon runner is currently in the ICU after suffering from heat stroke following an outdoor run on a particularly hot summer day. She was initially delirious in the emergency department, but progressed to coma and respiratory failure requiring mechanical ventilation. Her oral temperature is 42.1 °C. Which of the following would be most effective in reducing this patient’s severe hyperthermia?A.

Regularly scheduled alternating acetaminophen and ibuprofen

B.

Spraying room temperature water on the patient, followed by fanning

C.

Ice water immersion

D.

Dantrolene sodium, 2.5 mg/kg

E.

Application of ice packs to the groin and axilla

Hyperinsulinemia-euglycemia (HIE) therapy may be useful for toxicity related to which of the following?A.

Tricyclic antidepressants

B.

Calcium channel blockers

C.

Aspirin

D.

Digoxin

E.

Lithium

A 71-year-old female with a history of alcohol abuse is currently intubated in the ICU following a catastrophic spontaneous left basal ganglia hemorrhage with resultant herniation. You have just declared her brain dead. The patient’s family agrees to make her an organ donor, and the organ donation coordinator requests you initiate levothyroxine therapy. Which of the following benefits would be expected with this treatment?A.

Increase the number of solid organs available for transplant

B.

Eliminate the need for hepatic biopsy prior to liver transplant

C.

Eliminate the need for cardiac catheterization prior to heart transplant

D.

Eliminate the need for bronchoscopy prior to lung transplant

E.

Reduce the need for supplementation of sodium, potassium, calcium, and magnesium

Which of the following is not an element of the Full Outline of Unresponsiveness (FOUR) score?A.

Eye opening

B.

Respiratory function

C.

Brainstem reflexes

D.

Motor response

E.

Verbal response

A 23-year-old female is currently in the ICU with status asthmaticus. She was initially on noninvasive positive pressure ventilation, with an arterial blood gas (ABG) as follows: pH 7.13, pCO₂ 60 mmHg, PaO₂ is 61 mmHg, HCO₃ 24 mmol/L, and oxygen saturation of 90%. She is given continuous inhaled albuterol, intravenous steroids, and magnesium sulfate. She subsequently becomes more lethargic and is intubated, with settings as follows: volume assist-control, rate of 12 breaths/min, tidal volume of 500 cc, PEEP of 5 cm H₂O, and FiO₂ of 50%. Peak airway pressure is 50 cm H₂O and plateau pressure is 15 cm H₂O. A stat portable chest x-ray shows hyperinflation with no pneumothorax. A repeat ABG after 30 min of invasive ventilation shows the following: pH of 7.24, pCO₂ 49 mmHg, PaO₂ 71 mmHg, HCO₃ is 25 mmol/L. Which of the following should be performed next?A.

Increase rate to 16

B.

Increase tidal volume to 600 cc

C.

Initiate bicarbonate infusion

D.

Switch to pressure assist-control

E.

Maintain current settings

Which of the following mechanisms is implicated in super-refractory status epilepticus?A.

Influx of proinflammatory molecules

B.

Upregulation of NMDA receptors

C.

Upregulation of molecular transport molecules

D.

Downregulation of GABA receptors

E.

All of the above

A 85-year-old male with a history nephrolithiasis, mild dementia, and alcohol abuse presented to the emergency department after a fall from standing, and was found to a right holohemispheric subdural hematoma. His clot was evacuated successfully, in spite of his oozing diathesis in the operating room (INR on arrival was 1.4 with a platelet count of 88 × 10³/μL). His serum transaminases are twice the normal value, and he has had refractory chronic hyponatremia. He has had three convulsions during this week of hospitalization, in spite of levetiracetam therapy at 1.5 g twice a day. Over the past 24 h, he has had a marked increase in agitation. He has also just had a 5-s run of non-sustained ventricular tachycardia, and his systolic blood pressure is now 85 mmHg. You are considering discontinuing his levetiracetam and starting a new agent. Which of the following would be the best choice in this scenario?A.

Carbamazepine

B.

Phenytoin

C.

Valproate

D.

Lacosamide

E.

Topiramate

A 65-year-old male with a history of COPD on rescue albuterol and ipratropium is diagnosed with myasthenia gravis, and started on an acetylcholinesterase inhibitor. He returns several days later complaining of increased salivation and worsening bronchial secretions in the absence of fevers, purulent sputum, or increasing dyspnea. These symptoms are not relieved by use of his albuterol. On exam, he has slightly decreased air movement throughout both lung fields without any clear wheezing, no focal rales, and a normal inspiratory to expiratory ratio. Which treatment option is most likely to be beneficial?A.

Increase frequency of short-acting ß₂ agonist use

B.

Add a standing long-acting inhaled ß₂ agonist

C.

Add glycopyrrolate as needed

D.

Add inhaled corticosteroids

E.

Add oral systemic corticosteroids

Regarding states of impaired consciousness, which of the following statements regarding arousal and awareness is correct?A.

Coma: intact arousal, but impaired awareness

B.

Minimally conscious state: impaired arousal and impaired awareness

C.

Persistent vegetative state: intact arousal, but impaired awareness

D.

Locked-in state: intact arousal, but impaired awareness

E.

All of the above are correct

A 62-year-old female is currently in the ICU following craniotomy for clipping of a cerebral aneurysm. Postoperatively, she is noted to have an oxygen saturation of 92% on 50% non-rebreather face mask, and her respiratory rate is 32 breaths/min. She denies chest pain. Her blood pressure is 96/72 mmHg and heart rate is 120 beats/min. Nimodipine has been held according to blood pressure parameters. A portable chest x-ray shows hazy opacities bilaterally, and bedside echocardiogram shows decreased left ventricular systolic function with apical, septal, lateral, anterior, anteroseptal and inferolateral wall akinesis, along with apical ballooning. Which of the following should be performed next?A.

Intubate the patient and begin mechanical ventilation

B.

Call urgent cardiology consult for cardiac catheterization

C.

Start noninvasive positive airway pressure ventilation

D.

Administer broad spectrum antibiotics

E.

Administer albuterol and systemic corticosteroids

Which of the following is the most common etiology of acute spinal cord ischemia and infarction?A.

Atherosclerotic disease

B.

Rupture of an abdominal aortic aneurysm

C.

Degenerative spine disease

D.

Cardioembolic events

E.

Systemic hypotension in the setting of other disease processes

A 62-year-old female with a history of coronary artery disease has just been admitted to the ICU with a left-sided spontaneous basal ganglia hemorrhage. The patient takes 325 mg of aspirin daily at home, and you are considering platelet transfusion. Which of the following has been demonstrated regarding platelet transfusion in this setting?A.

Improved chances of survival to hospital discharge

B.

Decreased hospital length-of-stay

C.

Improved chances of survival at 3 months

D.

Improved modified Rankin scale at 3 months

E.

None of the above

Which of the following therapies has been shown to decrease the incidence of delayed cerebral ischemia (DCI) in the setting of subarachnoid hemorrhage (SAH)?A.

Atorvastatin

B.

Magnesium

C.

Methylprednisolone

D.

Nicardipine

E.

None of the above

A 70-year-old male with a history of diabetes, hypertension, and cigarette smoking (one pack per day for the last 40 years) is currently in the ICU with a COPD exacerbation. This is his third exacerbation this year, and was discharged from the hospital only 3 weeks prior. On your examination, he is alert, his breathing is labored, and he has rales at the right lung base. His vital signs are as follows: blood pressure 90/60 mmHg, heart rate 120 beats per minute, respirations 28 per minute, and temperature 38.3 °C. His oxygen saturation on 50% face mask is 93%, and his most recent PCO₂ is 55 mmHg. Labs are notable for the following: white blood cell count 14.4 × 10⁹/L with 90% neutrophils, blood urea nitrogen (BUN) 30 mg/dL, serum creatinine 1.2 mg/dL, and glucose 240 mg/dL. Ketones are negative. He is currently on noninvasive positive pressure ventilation at 10/5 cm H₂O and 50% FiO₂, and broad spectrum antibiotics have been administered. An hour later, the nurse pages you because his heart rate is now 140 beats per minute and irregular, blood pressure is 85 systolic, oxygen saturation is 85%, and he is minimally responsive. You now hear bilateral rales, most prominently in the right lung base, and scattered wheezes. Which of the following should be performed next?A.

Increase inspiratory pressure to 15 and FiO₂ to 100%

B.

Start a continuous diltiazem infusion and give intravenous furosemide

C.

Start a continuous phenylephrine infusion targeting a mean arterial pressure (MAP) > 65

D.

Give 125 mg of solumedrol and administer albuterol via nebulizer

E.

Intubate the patient and initiate mechanical ventilation

A 57-year-old male with a history of epilepsy is currently in the stroke unit following a large right middle cerebral artery infarction. A nasogastric tube has been inserted, and 24 h continuous enteral feeds have been initiated. The patient is currently on 100 mg of phenytoin every 8 h for seizure prophylaxis. Which of the following measures should be taken to prevent the patient from developing subtherapeutic phenytoin levels?A.

Change to 18 h tube feeds, and only administer phenytoin at night

B.

Change to 18 h tube feeds, and only administer phenytoin twice daily

C.

Switch from standard to hydrolyzed tube feeds

D.

Switch from standard to glycemic control tube feeds

E.

Hold tube feeds for 2 h before and after phenytoin administration

A 37-year-old female presents to the emergency department with approximately 2 weeks of progressively worsening clumsiness and drastic mood swings. Her past medical history is significant only for Crohn’s disease, for which she takes both natalizumab and infliximab. A contrast-enhanced CT scan of her head is performed, revealing hypodense, non-enhancing lesions in the cortical white matter of the frontal and parietal lobes. Despite treatment, the patient expires 1 month later. Which of the following is true regarding the most likely diagnosis?A.

The diagnosis may be confirmed via CSF analysis

B.

The pathologic process spares oligodendrocytes

C.

It is a prion-based disease

D.

The condition is universally fatal despite treatment

E.

All of the above

A 58-year-old female presents to the emergency department with dry cough, fever and rapidly progressive dyspnea over 1 week. She has a history of rheumatoid arthritis (RA) and is maintained on weekly methotrexate and daily prednisone (which was increased to 30 mg starting 1 month ago for an acute flare). She takes no other medications. Her vital signs are as follows: blood pressure 100/70 mmHg, heart rate 110 beats/min, respiratory rate 20 breaths/min, and temperature 38.0 °C. In the ED she develops progressive hypoxemia with oxygen saturation 92% on 100% nonrebreather, and is increasingly diaphoretic. She is emergently intubated, and a chest x-ray post intubation shows extensive bilateral lung opacities. Which of the following should be administered at this time?A.

Ceftriaxone and azithromycin

B.

Vancomycin and piperacillin-tazobactam

C.

Vancomycin, cefepime, and fluconzole

D.

Ceftriaxone, levofloxacin, and trimethoprim-sulfamethoxazole

E.

Tigecycline only

A 45-year-old woman undergoes uncomplicated transsphenoidal resection of a pituitary macroadenoma. She appears well hydrated and is not complaining of excessive thirst. Post-operatively, she is noted to have increased urine output. Serum sodium is 137 mEq/L, and serum osmolarity is 275 mOsm/kg. What is the most likely cause of her polyuria?A.

Syndrome of inappropriate antidiuretic hormone

B.

Diabetes insipidus

C.

Cerebral salt wasting

D.

Fluid mobilization

E.

All of the above are equally likely

A 36-year-old female with a recent lumbar puncture to rule out subarachnoid hemorrhage is now complaining of a severe headache unlike anything she has experienced previously. She reports her headache is worse when standing, and better upon lying flat. She is otherwise neurologically intact. All of the following medications may be beneficial in this scenario except:A.

Acetaminophen

B.

Ibuprofen

C.

Caffeine

D.

Aminophylline

E.

Methylprednisolone

Which of the following is the most common overall cause of acute myocardial infarction?A.

Coronary dissection

B.

Plaque rupture

C.

Imbalance between oxygen demand and supply across a fixed obstruction

D.

Coronary vasospasm

E.

Ischemia related to hypotension and decreased perfusion

A 78-year-old male is in the ICU recovering from sepsis and pneumonia. He was just recently extubated after 2 days of mechanical ventilation and sedation with a fentanyl infusion. Over the ensuing days, he develops worsening abdominal distention, poor bowel sounds, and no stool output. CT scan reveals significant colonic distention, but no mass or obstruction. Records demonstrate a normal routine colonoscopy performed 6 weeks ago. You have appropriately hydrated the patient, corrected any electrolyte abnormalities, placed a rectal tube, withheld all opiates, and given intravenous erythromycin, but to no avail. Abdominal x-rays continue to demonstrate marked cecal dilatation greater than 12 cm in diameter. What is the next best appropriate therapy for this patient?A.

Neostigmine

B.

Naloxone

C.

Metoclopromide

D.

Surgical consultation for hemicolectomy

E.

Endoscopic percutaneous cecostomy tube placement

Which of the following is the most common cerebral vascular malformation in the general population?A.

AV malformation

B.

Dural AV fistula

C.

Developmental venous anomaly

D.

Cavernous malformation

E.

Vein of Galen malformation

A 49-year-old female with a history of acute lymphoblastic leukemia and recent subcutaneous cerebrospinal fluid (CSF) reservoir placement presents to the emergency department with fever, chills, and increased confusion for the past 3 days. Her CSF reservoir was last accessed 1 week ago. A thorough work-up reveals no other obvious infectious source, and there is concern for CSF reservoir-associated meningitis. Which of the following is the most likely causative organism?A.

Coagulase-negative staphylococci

B.

Propionobacterium acnes

C.

Methicillin-resistant Staphylococcus aureus

D.

Klebsiella pneumoniae

E.

Neisseria meningitidis

A 47-year-old woman presents to the emergency department with headache, nausea, and vomiting. Non-contrast head CT is performed, revealing subarachnoid blood in the right Sylvian fissure, and conventional angiography reveals the presents of a large right-sided MCA aneurysm. The patient undergoes successful surgical clipping of her aneurysm, and is being observed in the ICU. On admission, the patient’s serum sodium was 142 mEq/L and the hematocrit was 37%; by the seventh post-operative day, the serum sodium is 127 mEq/L and the hematocrit is 44%. Bedside ultrasonography demonstrates an IVC diameter of approximately 0.9 cm. Which of the following interventions would be least reasonable at this time?A.

Fludrocortisone, 0.2 mg twice a day

B.

2% hypertonic saline, infused peripherally

C.

3% hypertonic saline, infused centrally

D.

Sodium chloride oral tablets

E.

1500 mL daily fluid restriction

Which of the following is true regarding central (non-infectious) fever?A.

Less common in subarachnoid hemorrhage

B.

More common versus infectious fever

C.

Earlier onset versus infectious fever

D.

Easier to confirm versus infectious fever

E.

All of the above

Flaccid paralysis is most commonly associated with which of the following forms of encephalitis?A.

West Nile

B.

Varicella zoster

C.

Rabies

D.

Herpes simplex

E.

Epstein-Barr

Which of the following would not be considered appropriate therapy for heparin-induced thrombocytopenia (HIT)?A.

Discontinuation of heparin products alone

B.

Danaparoid

C.

Fondaparinux

D.

Argatroban

E.

All of the above are acceptable treatment options

A 45-year-old male with severe blunt traumatic brain injury (TBI) from a motor vehicle collision suffered a ventricular fibrillation cardiac arrest at the time of injury with return of spontaneous circulation (ROSC) in the field after endotracheal intubation and one dose of epinephrine. On arrival to the emergency department, no regional wall motion abnormalities were noted on surface echocardiography and no ST segment changes were seen on the presenting EKG. Head CT revealed cerebral contusions but no extra-axial mass lesions. The patient is now in the ICU and found to be comatose without sedation. Mild therapeutic hypothermia to 33° is being considered in the management of this post-arrest patient. Which of the following statements is true?A.

Mild therapeutic hypothermia is contraindicated due to the risk of induced epilepsy

B.

Mild therapeutic hypothermia is contraindicated with any intracranial pathology on CT imaging

C.

Mild therapeutic hypothermia does not induce a clinically significant coagulopathy

D.

Patients who have sustained ROSC after an arrest associated with TBI do not benefit from therapeutic hypothermia

E.

Endovascular cooling is superior to surface cooling in young patients with ROSC

A 35-year-old male is in the intensive care unit following resection of a large right-sided meningioma. He is currently intubated and sedated on a continuous fentanyl infusion. The nurse calls you to the bedside due to concerns over “unusual ventilator waveforms”. Upon arrival, you note the following (see Image 1). What is the best way to describe this phenomenon?A.

Reverse triggering

B.

Double triggering

C.

Breath stacking

D.

Missed triggering

E.

None of the above; normal ventilator waveforms are present

A Comparison of Current Guidelines of Five International Societies on Clostridium difficile Infection Management

Clostridium difficile infection (CDI) is increasingly recognized as an emerging healthcare problem of elevated importance. Prevention and treatment strategies are constantly evolving along with the apperance of new scientific evidence and novel treatment methods, which is well-reflected in the differences among consecutive international guidelines. In this article, we summarize and compare current guidelines of five international medical societies on CDI management, and discuss some of the controversial and currently unresolved aspects which should be addressed by future research.

Development of Photodynamic Antimicrobial Chemotherapy (PACT) for Clostridium difficile

BACKGROUND

Clostridium difficile is the leading cause of antibiotic-associated diarrhoea and pseudo membranous colitis in the developed world. The aim of this study was to explore whether Photodynamic Antimicrobial Chemotherapy (PACT) could be used as a novel approach to treating C. difficile infections.

METHODS

PACT utilises the ability of light-activated photosensitisers (PS) to produce reactive oxygen species (ROS) such as free radical species and singlet oxygen, which are lethal to cells. We screened thirteen PS against C. difficile planktonic cells, biofilm and germinating spores in vitro, and cytotoxicity of effective compounds was tested on the colorectal adenocarcinoma cell-line HT-29.

RESULTS

Three PS were able to kill 99.9% of bacteria in both aerobic and anaerobic conditions, both in the planktonic state and in a biofilm, after exposure to red laser light (0.2 J/cm2) without harming model colon cells. The applicability of PACT to eradicate C. difficile germinative spores indirectly was also shown, by first inducing germination with the bile salt taurocholate, followed by PACT.

CONCLUSION

This innovative and simple approach offers the prospect of a new antimicrobial therapy using light to treat C. difficile infection of the colon.

Clostridium Difficile Infection from a Surgical Perspective

BACKGROUND

The incidence and the severity of Clostridium difficile infection (CDI) have increased significantly over the last decade, especially in high-risk populations such as patients with inflammatory bowel disease (IBD). Surgeons must be able to both identify and minimize the risk of CDI in their own surgical patients and determine which CDI patients will benefit from surgery.

PURPOSE

We sought to define the risk factors, compare the treatment options, define the surgical indications, and identify factors that affect surgical outcomes for CDI based on the currently available literature.

RESULTS

Antibiotic use, exposure to the C. difficile bacteria, IBD, and higher levels of co-morbidity are all risk factors for CDI. The majority of CDI can be treated with antibiotics. Severe or fulminant colitis, however, has a high potential for poor outcome, but experience and some data suggest a lower mortality rate with colectomy rather than with continued medical treatment. Open total abdominal colectomy with end ileostomy is typically the preferred surgical strategy. It is often difficult to determine which patients will fail medical management as some may not manifest clinical signs of severe infection. Surrogate parameters of failure of medical therapy include respiratory and/or renal insufficiency, age greater than 60 years, peripheral vascular disease, congestive heart failure, and coagulopathy, all of which have been associated with worse surgical outcomes. Evidence suggests that in appropriately selected patients, colectomy performed before the development of shock requiring vasopressors, respiratory failure, renal failure, multi-organ dysfunction, and mental status changes may reduce mortality of the most severe forms of colitis. For less severe or recurrent presentations, creation of a loop ileostomy with intra-operative colonic lavage, fecal microbiota transfer, and C. difficile vaccinations are being discussed but have only been studied in small case-controlled series.

CONCLUSIONS

Prevention, containment, and non-surgical treatment are the cornerstone of management for CDI. However, the most severe forms with toxic colitis benefit from involvement of a surgical team. Swift open total abdominal colectomy with end ileostomy in patients with severe or fulminant C. difficile colitis has the best chance to reduce mortality if it is not delayed until shock, end organ damage, vasopressor requirement, mental status changes develop. Less aggressive approaches may be appropriate for milder and refractory forms but require further study before their applicability can be determined.

Clostridium Difficile Infection from a Surgical Perspective

BACKGROUND

The incidence and the severity of Clostridium difficile infection (CDI) have increased significantly over the last decade, especially in high-risk populations such as patients with inflammatory bowel disease (IBD). Surgeons must be able to both identify and minimize the risk of CDI in their own surgical patients and determine which CDI patients will benefit from surgery.

PURPOSE

We sought to define the risk factors, compare the treatment options, define the surgical indications, and identify factors that affect surgical outcomes for CDI based on the currently available literature.

RESULTS

Antibiotic use, exposure to the C. difficile bacteria, IBD, and higher levels of co-morbidity are all risk factors for CDI. The majority of CDI can be treated with antibiotics. Severe or fulminant colitis, however, has a high potential for poor outcome, but experience and some data suggest a lower mortality rate with colectomy rather than with continued medical treatment. Open total abdominal colectomy with end ileostomy is typically the preferred surgical strategy. It is often difficult to determine which patients will fail medical management as some may not manifest clinical signs of severe infection. Surrogate parameters of failure of medical therapy include respiratory and/or renal insufficiency, age greater than 60 years, peripheral vascular disease, congestive heart failure, and coagulopathy, all of which have been associated with worse surgical outcomes. Evidence suggests that in appropriately selected patients, colectomy performed before the development of shock requiring vasopressors, respiratory failure, renal failure, multi-organ dysfunction, and mental status changes may reduce mortality of the most severe forms of colitis. For less severe or recurrent presentations, creation of a loop ileostomy with intra-operative colonic lavage, fecal microbiota transfer, and C. difficile vaccinations are being discussed but have only been studied in small case-controlled series.

CONCLUSIONS

Prevention, containment, and non-surgical treatment are the cornerstone of management for CDI. However, the most severe forms with toxic colitis benefit from involvement of a surgical team. Swift open total abdominal colectomy with end ileostomy in patients with severe or fulminant C. difficile colitis has the best chance to reduce mortality if it is not delayed until shock, end organ damage, vasopressor requirement, mental status changes develop. Less aggressive approaches may be appropriate for milder and refractory forms but require further study before their applicability can be determined.

Clostridium difficile infection in children: a comprehensive review

OBJECTIVE

To provide a comprehensive review of the literature relating to Clostridium difficile (C. difficile) infection (CDI) in the pediatric population.

METHODS

Two investigators conducted independent searches of PubMed, Web of Science, and Scopus until March 31st, 2013. All databases were searched using the terms 'Clostridium difficile infection', 'Clostridium difficile associated diarrhea' 'antibiotic associated diarrhea', 'C. difficile', in combination with 'pediatric' and 'paediatric'. Articles which discussed pediatric CDI were reviewed and relevant cross references also read and evaluated for inclusion. Selection bias could be a possible limitation of this approach.

FINDINGS

There is strong evidence for an increased incidence of pediatric CDI. Increasingly, the infection is being acquired from the community, often without a preceding history of antibiotic use. The severity of the disease has remained unchanged. Several medical conditions may be associated with the development of pediatric CDI. Infection prevention and control with antimicrobial stewardship are of paramount importance. It is important to consider the age of the child while testing for CDI. Traditional therapy with metronidazole or vancomycin remains the mainstay of treatment. Newer antibiotics such as fidaxomicin appear promising especially for the treatment of recurrent infection. Conservative surgical options may be a life-saving measure in severe or fulminant cases.

CONCLUSIONS

Pediatric providers should be cognizant of the increased incidence of CDI in children. Early and judicious testing coupled with the timely institution of therapy will help to secure better outcomes for this disease.

A unique strain of community-acquired Clostridium difficile in severe complicated infection and death of a young adult

Background

Clostridium difficile is the major cause of nosocomial antibiotic-associated diarrhoea with the potential risk of progressing to severe clinical outcomes including death. It is not unusual for Clostridium difficile infection to progress to complications of toxic megacolon, bowel perforation and even Gram-negative sepsis following pathological changes in the intestinal mucosa. These complications are however less commonly seen in community-acquired Clostridium difficile infection than in hospital-acquired Clostridium difficile infection. To the best of our knowledge, this was the first case of community-acquired Clostridium difficile infection of its type seen in Jamaica.

Case presentation

We report a case of a 22-year-old female university student who was admitted to the University Hospital of the West Indies, Jamaica with a presumptive diagnosis of pseudomembranous colitis PMC. She presented with a 5-day history of diarrhoea following clindamycin treatment for coverage of a tooth extraction due to a dental abscess. Her clinical condition deteriorated and progressed from diarrhoea to toxic megacolon, bowel perforation and Gram-negative sepsis. Clostridium difficile NAP12/ribotype 087 was isolated from her stool while blood cultures grew Klebsiella pneumoniae. Despite initial treatment intervention with empiric therapy of metronidazole and antibiotic clearance of Klebsiella pneumoniae from the blood, the patient died within 10 days of hospital admission.

Conclusions

We believe that clindamycin used for coverage of a dental abscess was an independent risk factor that initiated the disruption of the bowel micro-flora, resulting in overgrowth of Clostridium difficile NAP12/ribotype 087. This uncommon strain, which is the same ribotype (087) as ATCC 43255, was apparently responsible for the increased severity of the infection and death following toxic megacolon, bowel perforation and pseudomembranous colitis involving the entire large bowel. K. pneumoniae sepsis, resolved by antibiotic therapy was secondary to Clostridium difficile infection. The case registers community-acquired Clostridium difficile infection as producing serious complications similar to hospital-acquired Clostridium difficile infection and should be treated with the requisite importance.

Clinical approach to severe Clostridium difficile infection: update for the hospital practitioner

The rising incidence of Clostridium difficile (C. difficile) infection or CDI is now a problem of pandemic proportions. The NAP1 hypervirulent strain of C. difficile is responsible for a majority of recent epidemics and the widespread use of fluoroquinolone antibiotics may have facilitated the selective proliferation of this strain. The NAP1 strain also is more likely to cause severe and fulminant colitis characterized by marked leukocytosis, renal failure, hemodynamic instability, and toxic megacolon. No single test suffices to diagnose severe CDI, instead; the clinician must rely on a combination of clinical acumen, laboratory testing, and radiologic and endoscopic modalities. Although oral vancomycin and metronidazole are considered standard therapies in the medical management of CDI, recently it has been demonstrated that vancomycin is the more effective antibiotic in cases of severe disease. Moreover, early surgical consultation is necessary in patients who do not respond to medical therapy or who demonstrate rising white blood cell counts or hemodynamic instability indicative of fulminant colitis. Subtotal colectomy with end ileostomy is the procedure of choice for fulminant colitis. When applied to select patients in a judicious and timely fashion, surgery can be a life-saving intervention. In addition to these therapeutic approaches, several investigational treatments including novel antibiotics, fecal bacteriotherapy and immunotherapy have shown promise in the care of patients with severe CDI.

Clostridium difficile Infection and Proton Pump Inhibitor Use in Hospitalized Pediatric Cystic Fibrosis Patients

Children with cystic fibrosis (CF) often take proton pump inhibitors (PPIs), which helps improve efficacy of fat absorption with pancreatic enzyme replacement therapy. However, PPI use is known to be associated with Clostridium difficile-(C. diff-) associated diarrhea (CDAD). We retrospectively evaluated the incidence of C. diff infection from all pediatric hospital admissions over a 5-year period at a single tertiary children's hospital. We found significantly more C. diff-positive stool tests in hospitalized patients with CF compared to patients with no diagnosis of CF. However, use of a PPI was not associated with an increased risk of CDAD in hospitalized CF patients. In summary, C. diff infection is more common in hospitalized pediatric CF patients although PPI use may not be a risk factor for CDAD development in this patient population.