Acute respiratory distress syndrome from chlorine inhalation during a swimming pool accident: a case report and review of the literature

Chlorine inhalation can result in significant morbidity and mortality. The most common clinical ramification is mucosal irritation. Rarely, depending upon the degree of exposure, patients can develop acute respiratory distress syndrome. Management is usually supportive with an unproven role for inhaled or systemic corticosteroids. A case of a young woman who developed respiratory failure secondary to acute respiratory distress syndrome from accidental exposure to chlorine fumes at a community swimming pool is described. The patient suffered a prolonged hospitalization with the need for mechanical ventilation. Despite limited data to support the decision, the patient was started on treatment with corticosteroids. She recovered completely from her illness and was discharged home without supplemental oxygen. A concise discussion of chlorine inhalation injury and a literature review on the utility of inhaled and/or systemic corticosteroids for this clinical entity is presented.     

The optimal cut-off for predicting large oesophageal varices using transient elastography is disease specific

The diagnosis of cirrhosis requires screening for oesophageal varices by upper gastrointestinal endoscopy. In many countries, serological tests and elastography are replacing liver biopsy for diagnosing cirrhosis. The aims of this study were to see whether there was an optimal cut-off of liver stiffness that could predict the presence of large (>F2) oesophageal varices and whether this was disease specific. A total of two hundred and twenty-two patients with all cause cirrhosis (Child class A) were screened, and 211 had successful elastography and are included in the analysis. Of the patients studied, one hundred and thirty-two patients had no or small F1 varices and 79 had large varices. Liver stiffness of 19.8 kPa had a negative predictive value of 91% and a positive predictive value of 55% with an area under the curve (AUC) on receiver operating characteristics (ROC) of 0.73 in differentiating between small and large varices. Seven patients with large varices would have been incorrectly classified. In the 157 patients with hepatitis C as the aetiology of cirrhosis, the negative predictive value was 98% and only one patient was misclassified. Liver stiffness was superior in diagnostic accuracy to platelet count in all patients. A liver stiffness of >19.8 kPa could be utilized as a cut-off for endoscopy and beta blocker utilization, particularly in patients with hepatitis C.     

Effects of heavy drinking, binge drinking, and family history of alcoholism on regional brain metabolites

BACKGROUND: The main goals are to investigate the effects of chronic active heavy drinking on N-acetylaspartate (NAA) and other metabolites throughout the brain and to determine whether they are affected by family history (FH) of alcoholism and long-term drinking pattern. METHODS: Forty-six chronic heavy drinkers (HD) and 52 light drinkers (LD) were recruited from the community and compared on measures of regional brain structure using magnetic resonance imaging and measures of common brain metabolites in gray matter (GM) and white matter (WM) of the major lobes, subcortical nuclei, brainstem, and cerebellum using short-echo time magnetic resonance spectroscopic imaging. Regional atrophy-corrected levels of NAA, myoinositol (mI), creatine, and choline-containing metabolites were compared as a function of group, FH of alcoholism, and bingeing. RESULTS: Frontal WM NAA was lower in FH-negative HD than FH-positive HD and tended to be lower in women than men. Creatine-containing metabolites in parietal GM were higher in HD than LD. FH-negative compared with FH-positive HD also had more mI in the brainstem and tended to have lower NAA and more mI in frontal GM. Although parietal GM NAA was not significantly lower in HD than LD, it was lower in non-binge drinkers than bingers. Frontal WM NAA was lower in HD than LD, with the difference driven by a small number of women, FH-negative HD, and older age. Lower frontal WM NAA in HD was associated with lower executive and working memory functions and with lower P3b amplitudes at frontal electrodes. CONCLUSIONS: Community-dwelling HD who are not in alcoholism treatment have brain metabolite changes that are associated with lower brain function and are likely of behavioral significance. Age, FH, and binge drinking modulate brain metabolite abnormalities. Metabolite changes in active HD are less pronounced and present with a different spatial and metabolite pattern than reported in abstinent alcoholics.     

Plasma elimination of cholyl‐lysyl‐fluorescein (CLF): a pilot study in patients with liver cirrhosis

Abstract: Background: Cholyl‐lysyl‐fluorescein (CLF) is a fluorescein‐labelled bile acid whose biological behaviour closely resembles that of naturally occurring cholyl glycine. Aim: The aim of this study was to analyze the CLF plasma elimination in patients with liver cirrhosis. Methods: A dose of CLF at 0.02 mg/kg b.w. was administered i.v. in 26 patients with liver cirrhosis and 9 healthy volunteers. Blood samples were collected before injection and then at 10 min intervals over 60 min. Plasma fluorescence was measured by a luminescence spectrometer and residual fluorescence over the time of the study was compared in each group. Routine liver function tests (rLFTs) were performed before each injection. Results: Plasma elimination of CLF was significantly impaired in patients with cirrhosis compared to healthy subjects with p values <0.0001 at each analyzed time point. CLF test showed 100% sensitivity for liver cirrhosis when residual fluorescence was measured 30, 40, 50 and 60 min after injection. Routine LFTs showed 85% sensitivity for bilirubin, 84% for total bile acids, 69% for aspartate aminotransferase 62% for albumin and 50% for alkaline phosphatase. CLF elimination measured 60 min after injection correlated with Child‐Pugh score (r=0.3945; p<0.05) and albumin (r_s=0.6451; p<0.001). No adverse reaction or side effects of CLF were observed. Conclusions: CLF test clearly distinguished between the two analyzed groups and was more sensitive than routine liver function tests. The test appears safe, simple to perform and analyze and after validation in larger cohorts of patients may have the potential to become a useful dynamic test of liver function.     

Plasma elimination of cholyl-lysyl-fluorescein (CLF): a pilot study in patients with liver cirrhosis

BACKGROUND: Cholyl-lysyl-fluorescein (CLF) is a fluorescein-labelled bile acid whose biological behaviour closely resembles that of naturally occurring cholyl glycine. AIM: The aim of this study was to analyze the CLF plasma elimination in patients with liver cirrhosis. METHODS: A dose of CLF at 0.02 mg/kg b.w. was administered i.v. in 26 patients with liver cirrhosis and 9 healthy volunteers. Blood samples were collected before injection and then at 10 min intervals over 60 min. Plasma fluorescence was measured by a luminescence spectrometer and residual fluorescence over the time of the study was compared in each group. Routine liver function tests (rLFTs) were performed before each injection. RESULTS: Plasma elimination of CLF was significantly impaired in patients with cirrhosis compared to healthy subjects with p values <0.0001 at each analyzed time point. CLF test showed 100% sensitivity for liver cirrhosis when residual fluorescence was measured 30, 40, 50 and 60 min after injection. Routine LFTs showed 85% sensitivity for bilirubin, 84% for total bile acids, 69% for aspartate aminotransferase 62% for albumin and 50% for alkaline phosphatase. CLF elimination measured 60 min after injection correlated with Child-Pugh score (r=0.3945; p<0.05) and albumin (rs=0.6451; p<0.001). No adverse reaction or side effects of CLF were observed. CONCLUSIONS: CLF test clearly distinguished between the two analyzed groups and was more sensitive than routine liver function tests. The test appears safe, simple to perform and analyze and after validation in larger cohorts of patients may have the potential to become a useful dynamic test of liver function.     

Evaluation of tuberculosis diagnostics in children: 1. Proposed clinical case definitions for classification of intrathoracic tuberculosis disease. Consensus from an expert panel

There is a critical need for improved diagnosis of tuberculosis in children, particularly in young children with intrathoracic disease as this represents the most common type of tuberculosis in children and the greatest diagnostic challenge. There is also a need for standardized clinical case definitions for the evaluation of diagnostics in prospective clinical research studies that include children in whom tuberculosis is suspected but not confirmed by culture of Mycobacterium tuberculosis. A panel representing a wide range of expertise and child tuberculosis research experience aimed to develop standardized clinical research case definitions for intrathoracic tuberculosis in children to enable harmonized evaluation of new tuberculosis diagnostic technologies in pediatric populations. Draft definitions and statements were proposed and circulated widely for feedback. An expert panel then considered each of the proposed definitions and statements relating to clinical definitions. Formal group consensus rules were established and consensus was reached for each statement. The definitions presented in this article are intended for use in clinical research to evaluate diagnostic assays and not for individual patient diagnosis or treatment decisions. A complementary article addresses methodological issues to consider for research of diagnostics in children with suspected tuberculosis.     

Small changes in enzyme function can lead to surprisingly large fitness effects during adaptive evolution of antibiotic resistance

In principle, evolutionary outcomes could be largely predicted if all of the relevant physicochemical variants of a particular protein function under selection were known and integrated into an appropriate physiological model. We have tested this principle by generating a family of variants of the tetracycline resistance protein TetX2 and identified the physicochemical properties most correlated with organismal fitness. Surprisingly, small changes in the K_m(MCN), less than twofold, were sufficient to produce highly successful adaptive mutants over clinically relevant drug concentrations. We then built a quantitative model directly relating the in vitro physicochemical properties of the mutant enzymes to the growth rates of bacteria carrying a single chromosomal copy of the tet(X2) variants over a wide range of minocycline (MCN) concentrations. Importantly, this model allows the prediction of enzymatic properties directly from cellular growth rates as well as the physicochemical-fitness landscape of TetX2. Using experimental evolution and deep sequencing to monitor the allelic frequencies of the seven most biochemically efficient TetX2 mutants in 10 independently evolving populations, we showed that the model correctly predicted the success of the two most beneficial variants tet(X2)_T280A and tet(X2)_N371I. The structure of the most efficient variant, TetX2_T280A, in complex with MCN at 2.7 Å resolution suggests an indirect effect on enzyme kinetics. Taken together, these findings support an important role for readily accessible small steps in protein evolution that can, in turn, greatly increase the fitness of an organism during natural selection.     

Residency Training in Emergency Ultrasound: Fulfilling the Mandate

Although bedside ultrasound is listed in the Model of the Clinical Practice of Emergency Medicine as an integral diagnostic procedure, the manner in which the didactic, hands-on, and experiential components of emergency ultrasound are taught is not specifically prescribed by the Residency Review Committee for Emergency Medicine (RRC-EM) or any single sponsoring group. Seven professional organizations [the American Board of Emergency Medicine (ABEM), the American College of Emergency Medicine (ACEP), the Council of Emergency Medicine Residency Directors (CORD), the Emergency Medicine Residents Association (EMRA), the National Association of EMS Physicians (NAEMSP), the RRC-EM, and the Society for Academic Emergency Medicine (SAEM)] developed the Scope of Training Task Force, with the goal of identifying emerging areas of clinical importance to the specialty of emergency medicine, including emergency department (ED) ultrasound. The Task Force then identified a group of recognized authorities to thoughtfully address the issue of ED ultrasound training. This report represents a consensus of these identified experts on how emergency ultrasound training should be incorporated into emergency medicine residency programs.     

Associated conditions in myasthenia gravis: response to thymectomy

To compare the response of thymectomy in patients with associated conditions (PWAC) and without associated conditions (PWOAC). Comparative, retrospective. 198 patients with the established diagnosis of myasthenia gravis who had a thymectomy between 1987 and 2000, and who were folowed up for at least 3 years. We formed two groups, one with associated conditions and the second without associated conditions. The patients were divided into four groups: (i) patients in remission, (ii) patients with improvement, (iii) patients without changes, and (iv) patients whose condition worsened. Associated conditions (AC) were found in 49 patients (26%). The main associated conditions were hyperthyroidism in 16 patients (33%) hypothyroidism in seven (14%), rheumatoid arthritis in five (10%) and hypothyroidism and Sjogren syndrome in three (6%). Concerning the response of thymectomy, 13 patients WAC showed remission (27%), vs. 54 patients WOAC (39%). Twenty patients WAC showed improvement (41%) vs. 46 WOAC (33%). Thirteen patients WAC had no changes (27%) vs. 37 WOAC (26%). Finally, in three patients WAC their condition worsened (6%) vs. three WOAC (2%). The response to thymectomy was high (69%) in both groups. We did not identify significant differences.     

Magnetic Resonance Angiography of a Posterior Cerebral Artery Occlusion

A 45-year-old woman suddenly had severe pain in the right eye and blurred vision. Physical findings were normal except for left homonymous hemianopia. Laboratory test results were normal. However, magnetic resonance images showed evidence of cerebral infarctions in the right posterior cerebral artery distribution. In addition, magnetic resonance angiography was consistent with absent flow of that vessel.