A Physician With Thigh Pain

To prevent death, necrotizing soft-tissue infections should be diagnosed quickly and treated with broad-spectrum antibiotics and surgical debridement.

Predicting bacteremia based on nurse-assessed food consumption at the time of blood culture

BACKGROUND

Bacteremia and its complications are important causes of morbidity and mortality in hospitalized patients. However, the yield of blood cultures is relatively low, with many false-positive results from bacterial contamination.

METHODS

We investigated the relationship between patient food consumption and the presence of bacteremia. This was an observational analysis of a cohort of 1179 patients who underwent blood culture analysis between January 2005 and December 2009. Patients with anorexia-inducing conditions, such as gastrointestinal illness and malignant disease treated with chemotherapy, were excluded. Food consumption was rated by nurses as the percentage of food consumed during the meal preceding the blood culture. Groupings were as follows: low consumption (<50%), moderate (>50% to <80%), and high (>80%).

RESULTS

Low consumption was observed in 39.8% of patients, moderate in 17.8%, and high in 41.6%. The average body temperature was 38.1 ± 1.1°C. Bacteremia was present in 18.5%, 3.9%, and 1.4% of patients in the low, moderate, and high food consumption groups, respectively. The negative predictive value was 98.3%, suggesting that bacteremia is very unlikely in the setting of good food intake.

CONCLUSION

Bacteremia is an unlikely occurrence in hospitalized patients who maintain adequate food consumption at the time of blood culture.

Perspective: Uses and misuses of thresholds in diagnostic decision making

The concept of thresholds plays a vital role in decisions involving the initiation, continuation, and completion of diagnostic testing. Much research has focused on the development of explicit thresholds, in the form of practice guidelines and decision analyses. However, these tools are used infrequently; most medical decisions are made at the bedside, using implicit thresholds. Study of these thresholds can lead to a deeper understanding of clinical decision making. The authors examine some factors constituting individual clinicians' implicit thresholds. They propose a model for static thresholds using the concept of situational gravity to explain why some thresholds are high, and some low. Next, they consider the hypothetical effects of incorrect placement of thresholds (miscalibration) and changes to thresholds during diagnosis (manipulation). They demonstrate these concepts using common clinical scenarios. Through analysis of miscalibration of thresholds, the authors demonstrate some common maladaptive clinical behaviors, which are nevertheless internally consistent. They then explain how manipulation of thresholds gives rise to common cognitive heuristics including premature closure and anchoring. They also discuss the case where no threshold has been exceeded despite exhaustive collection of data, which commonly leads to application of the availability or representativeness heuristics. Awareness of implicit thresholds allows for a more effective understanding of the processes of medical decision making and, possibly, to the avoidance of detrimental heuristics and their associated medical errors. Research toward accurately defining these thresholds for individual physicians and toward determining their dynamic properties during the diagnostic process may yield valuable insights.

Selective targeting of a laccase from Stachybotrys chartarum covalently linked to a carotenoid-binding peptide

Atwo-step targeting strategy was used to identify improved laccases for bleaching carotenoid-containing stains on fabric. We first applied a modified phage display technique to identify peptide sequences capable of binding specifically to carotenoid stains and not to fabric. Prior deselection on the support on which the carotenoid was localized, increased stringency during the biopanning target selection process, and analysis of the phage peptides' binding to the target after acid elution and polymerase chain reaction (PCR) postacid elution, were used to isolate phage peptide libraries with increased binding selectivity and affinity. Peptide sequences were selected based on identified consensus motifs. We verified the enhanced carotenoid-binding properties of the peptide YGYLPSR and subsequently cloned and expressed C-terminal variants of laccase from Stachybotrys chartarum containing carotenoid-binding peptides YGYLPSR, IERSAPATAPPP, KASAPAL, CKASAPALC, and SLLNATK. These targeted peptide-laccase fusions demonstrate enhanced catalytic properties on stained fabrics.

Hemolytic anemia

Hemolysis presents as acute or chronic anemia, reticulocytosis, or jaundice. The diagnosis is established by reticulocytosis, increased unconjugated bilirubin and lactate dehydrogenase, decreased haptoglobin, and peripheral blood smear findings. Premature destruction of erythrocytes occurs intravascularly or extravascularly. The etiologies of hemolysis often are categorized as acquired or hereditary. Common acquired causes of hemolytic anemia are autoimmunity, microangiopathy, and infection. Immune-mediated hemolysis, caused by antierythrocyte antibodies, can be secondary to malignancies, autoimmune disorders, drugs, and transfusion reactions. Microangiopathic hemolytic anemia occurs when the red cell membrane is damaged in circulation, leading to intravascular hemolysis and the appearance of schistocytes. Infectious agents such as malaria and babesiosis invade red blood cells. Disorders of red blood cell enzymes, membranes, and hemoglobin cause hereditary hemolytic anemias. Glucose-6-phosphate dehydrogenase deficiency leads to hemolysis in the presence of oxidative stress. Hereditary spherocytosis is characterized by spherocytes, a family history, and a negative direct antiglobulin test. Sickle cell anemia and thalassemia are hemoglobinopathies characterized by chronic hemolysis.

Ethics in Japanese health care: a perspective for clinical nurse specialists

Bioethical issues relevant to nurses in Japan are described in this article. Significant Japanese values and behavior patterns, the impact of religion on ethical concerns, patient and family roles in illness, and relationships with the physician are described. Within this context, Japanese nursing involvement in ethics and selected ethical issues are explored with examples.

An experience in Japanese academic medicine

The Japanese health care system has been highly praised for its universal access, freedom of patient choice, maintenance of a private system, and creative funding. Japanese citizens enjoy general good health, low infant mortality, and long life expectancy. Nevertheless, aspects of Japanese medical education, both graduate and undergraduate, and the structure of academic departments differ from those seen in the United States. A sabbatical spent teaching general internal medicine in Japan provided the experience for this review of the Japanese system. I describe the structure and function of departments of medicine and observations made at daily clinical teaching exercises in hospitals throughout the country.

Aortoenteric fistula and perigraft infection: evaluation with CT

A blinded retrospective study was performed to determine the sensitivity and specificity of computed tomography (CT) in detecting perigraft infection (PGI) and aortoenteric fistula (AEF), rare but devastating complications of aortic reconstructive surgery. Two observers independently reviewed CT scans in 55 cases including AEF (n = 23); PGI (n = 12); and normal, noninfected grafts (n = 20). Each scan was assessed for ectopic gas, focal bowel wall thickening, perigraft fluid, perigraft soft tissue, pseudoaneurysm formation, disruption of the aneurysmal wrap, and increased soft tissue between the graft and surrounding wrap. Comparison of CT findings with operative results revealed that each observer correctly identified as abnormal 33 of 35 cases of PGI either with or without AEF (sensitivity, 94%) and that results were falsely positive in three cases (specificity, 85%). CT findings ranged from large amounts of perigraft soft tissue and ectopic gas to subtle findings of minimal or no abnormalities; thus, strict criteria must be applied to the interpretation of CT scans after aortic surgery. Although CT is not 100% sensitive or specific, the authors conclude that it will continue to be valuable for diagnosing PGI and AEF.

Iatrogenic illness

These discussions are selected from the weekly staff conferences in the Department of Medicine, University of California, San Francisco. Taken from transcriptions, they are prepared by Homer A. Boushey, MD, Professor of Medicine, under the direction of Lloyd H. Smith, Jr, MD, Professor of Medicine and Associate Dean in the School of Medicine. Requests for reprints should be sent to the Department of Medicine, University of California, San Francisco, School of Medicine, San Francisco, CA 94143.

Biochemical and clinical aspects of amyloidosis

These discussions are selected from the weekly staff conferences in the Department of Medicine, University of California, San Francisco. Taken from transcriptions, they are prepared by Drs Homer A. Boushey, Associate Professor of Medicine, and David G. Warnock, Associate Professor of Medicine, under the direction of Dr Lloyd H. Smith, Jr, Professor of Medicine and Associate Dean in the School of Medicine. Requests for reprints should be sent to the Department of Medicine, University of California, San Francisco, School of Medicine, San Francisco, CA 94143.

Phlegmonous gastritis and Hemophilus influenzae peritonitis in a patient with alcoholic liver disease

A patient with alcoholic liver disease and ascites had Haemophilus influenzae peritonitis and died in spite of vigorous antibiotic therapy. At autopsy, a phlegmonous gastritis was found as a likely cause of the peritonitis. Phlegmonous gastritis is an uncommon cause of unexplained gastrointestinal symptoms in alcoholics and in the elderly, and it may be pathogenetic in rare patients with bacterial peritonitis of unclear source.

Barrett's ulcer of the esophagus. Previously unrecognized cause of acquired esophagorespiratory fistula

Acquired fistulas between the esophagus and tracheobronchial tree are usually associated with malignancy of the esophagus, lung, or trachea. Less commonly, fistulas result from trauma or inflammation involving these structures. Untreated fistulas of any cause lead to fatal complications of aspiration. Although the prognosis in cases of malignant fistula is poor, the recognition and surgical management of nonmalignant fistulas may result in cure. An acquired esophagobronchial fistula resulting from a Barrett's ulcer of the esophagus, a previously unreported cause, is described, and the differential diagnosis and treatment of nonmalignant esophagorespiratory fistulas are discussed.

Clinical spectrum of pulmonary mucormycosis

Pulmonary mucormycosis is an uncommon, but important, opportunistic fungal pneumonia which is often diagnosed post-mortem. This review emphasizes clinical and pathologic characteristics of pulmonary mucormycosis that differentiate this infection from other fungal pneumonias. The most common clinical presentation of pulmonary mucormycosis is a rapidly progressive pneumonia with diffuse infiltrates on chest radiographic examination of a patient with an underlying hematologic malignancy treated with immunosuppressive drugs. Other immunocompromised hosts at risk for pulmonary mucormycosis include patients with diabetes mellitus who may develop a distinctive endobronchial form of this disease. Early consideration of this diagnosis, along with aggressive diagnostic evaluation, are critical to effective therapy and patient survival. While treatment with amphotericin B is the mainstay of therapy for pulmonary mucormycosis, diabetics with endobronchial disease may benefit from early, aggressive surgical resection of the involved lung tissue.

The predictive value of physical examinations for ascites

To determine the predictive value of physical signs for ascites, we compared the results of physical examination with those of abdominal sonography in 90 men in hospital with liver disease. The positive predictive values of shifting dullness and prominent fluid waves were low (51% and 73%). We divided the patients into two groups: those with prolonged prothrombin times (72% prevalence of ascites by sonogram), and those with normal prothrombin times (15% prevalence). In patients with prolonged prothrombin times, a prominent fluid wave had a very high positive predictive value for ascites (96%). Many patients with prolonged prothrombin times had ascites despite negative physical signs. In contrast, in those with normal prothrombin times, both shifting dullness and prominent fluid waves were usually falsely positive. Patients with normal prothrombin times and no shifting dullness rarely (2%) had ascites. The predictive value of physical signs for ascites depends on the prevalence of ascites in groups of patients that are examined. The prothrombin time is a useful index for identifying inpatients with a high or low prevalence of ascites and the predictive value of physical signs is enhanced by interpreting them in combination with a patient's prothrombin time.

Dermatomyositis associated with chronic myelogenous leukemia

Dermatomyositis and polymyositis have been well established in association with malignant neoplastic disease. Most commonly, this association has been noted in patients with solid tumors rather than in patients with neoplasms of hematopoietic origin. We describe here a patient with chronic myelogenous leukemia who developed typical dermatomyositis, which responded to therapy with corticosteroids. This concurrence has been reported in only one previous patient to our knowledge. The nature and implications of the association of dermatomyositis and neoplasia are discussed.

Aortoesophageal fistula after perigraft abscess with characteristic CT findings

Aortoesophageal fistula is a rare cause of massive gastrointestinal hemorrhage, and may occur as a sequela to prosthetic replacement of the thoracic aorta. Esophageal compression necrosis with leakage of microorganisms into the proximal suture line is probably central to pathogenesis. Like the more common aortoduodenal fistula, diagnosis by traditional radiographic and endoscopic methods is difficult. We report here such a fistula, in which computed tomographic soft tissue abnormalities were characteristic of perigraft abscess; fistulization occurred subsequently. CT holds potential for being a sensitive study to show localized perivascular infection, an important precursor to aortoenteric fistula, and as such should be positive early in the development of a fistula.