Anticipation of the difficult airway: preoperative airway assessment, an educational and quality improvement tool.

BACKGROUND: Assessment of the potentially difficult airway (DA) is a critical aspect of resident education. We investigated the impact of a new assessment form on airway prediction and management by anaesthesia residents. We hypothesized that residents would demonstrate improvement in evaluation of DAs over the study duration. METHODS: After IRB approval, anaesthesia residents were randomized into two groups: control (existing form) and experimental (new form). Data were collected prospectively from August 2008 to May 2010 on all non-obstetric adult patients undergoing non-emergent surgery. RESULTS: Eight thousand three hundred and sixty-four independent preoperative assessments were collected and 8075 were analysed. The experimental group had the higher completion rate than the control group (94.3% vs 84.3%, P=0.001). DA prediction was higher for the control group (71.2%) compared with the experimental group (69.1%; P=0.032). A significant improvement in prediction rates was found over time for the experimental group (likelihood estimate=0.00068, P=0.031). CONCLUSIONS: The use of a comprehensive airway assessment did not improve resident ability to predict a DA in an academic, tertiary-based hospital, anaesthesiology residency training programme.

[Distribution of HBV genotypes in the Czech population--pilot study]. / Distribuce genotypu HBV v ceské populaci--pilotní studie.

A compact structure of the hepatitis B virus genome does not provide much space for development of mutations capable of further replication. In spite of that, 7 genotypes have been described so far. Discovery of the hepatitis B virus (HBV) genome diversity led to a range of further questions. Individual genotypes are subjects of investigation these days as for the pattern of disease transmission, course of disease, and consequences of an infection. The aim of this pilot study was to describe genotype distribution in the infected population of the Czech Republic. Moreover, epidemiological and clinical characteristics were monitored in our sample. We studied a group of 65 patients with positive HBsAg from which 48 samples of patients were genotyped. PCR (polymerase chain reaction) method was used in order to amplify S region of the HBV genome. Direct sequencing of PCR products was used, this is the most accurate method for genotype identification. A relatively uniform genotypic distribution was identified within the study population--only 2 genotypes, A and D, were found. Genotype A was identified in 35 (73%) patients and genotype D in 13 (27%) patients. No statistically significant association between the particular genotype and epidemiological and clinical parameters was proved in this pilot study. This study brings basic information on genotype distribution. A possible proof of correlation with clinical and epidemiological characteristics will require examination of a larger sample of patients.

Genotypic distribution of TT virus (TTV) in a Czech population: evidence for sexual transmission of the virus.

BACKGROUND: TTV is a new DNA virus distinguished by its high degree of strain heterogeneity. The geographic clustering of viral genotypes suggests frequent community transmission. While no specific human disease has yet been linked to it, a transmission mechanism that facilitates strain diversity may eventually select for a strain that will become pathogenic. OBJECTIVE: This study was performed to examine the prevalence, genotypic distribution, and mode of transmission of TTV in detail. STUDY DESIGN: Three groups of study subjects were recruited between October 1998 and January 2000 in Prague, Czech Republic. Group 1 included 152 injection drug users with liver disease; group 2 included 102 persons with liver disease who denied ever using injection drugs; group 3 included 111 prospective blood donors. TTV DNA was detected from blood by a semi-nested PCR assay, and a selected set of PCR products was genotyped by direct sequencing. Factors associated with TTV prevalence in groups 1 and 2 subjects were compared. RESULTS: TTV was detected in 15.8, 13.7, and 13.5% of Groups 1, 2, and 3 subjects, respectively (P>0.05). The most common genotype was 2 (54%), followed by 1 (13%). The prevalence of TTV viremia was nearly three times higher in persons with a present or past history of hepatitis B compared to those without (P<0.05). TTV prevalence increased proportionately with the number of lifetime sex partners in both groups (P<0.05); it was highest (32%) among non-users of injection drugs who had five or more lifetime sex partners. CONCLUSION: TTV prevalence in the Czech population is similar among blood donors, persons with liver disease, as well as in a high-risk population of injection drug users. TTV appears to be sexually transmitted.

Genotypic and epidemiologic characteristics of hepatitis C virus infections among recent injection drug user and nonuser populations.

The recent surge in injection drug use (IDU) in Prague, Czech Republic, provided an opportunity to compare the distribution of hepatitis C virus (HCV) genotypes among recent injection drug users and nonusers. We provide evidence that the most common HCV subtype, 1b, has been circulating in Prague longer than the other subtypes but that IDU practice has magnified its recent prevalence, and that the primary drug of choice among IDU subjects appears to influence the prevalence of a particular HCV subtype.

Bcl-2 inhibits apoptosis induced by mitochondrial uncoupling but does not prevent mitochondrial transmembrane depolarization.

Bcl-2 overexpression protects cells from apoptosis induced by many cytotoxic agents. In this study, we investigated the effects of uncoupling mitochondrial electron transport in both HL60 wild-type and Bcl-2-overexpressing cells using the protonophore carbonyl cyanide m-chlorophenylhydrazone. We found that uncoupling mitochondrial electron transport induced apoptosis in wild-type, but not in Bcl-2-overexpressing cells. To investigate the mechanism of action of Bcl-2-mediated inhibition of cyanide m-chlorophenylhydrazone-induced apoptosis, we measured the mitochondrial transmembrane potential (DeltaPsi(m)) after uncoupling mitochondrial electron transport and found that both HL-60 wild-type and Bcl-2-overexpressing cells similarly depolarize following cyanide m-chlorophenylhydrazone exposure. Western blot analysis demonstrated that Bcl-2 overexpression did not completely block cytochrome c release from mitochondria after uncoupling mitochondrial electron transport. Since Bcl-2 may act as an antioxidant, we studied the effect of altering the cellular redox state prior to uncoupling mitochondrial electron transport in Bcl-2-overexpressing cells. Depletion of mitochondrial (but not cytosolic) glutathione induced apoptosis in Bcl-2-overexpressing cells and negated the protective effect of Bcl-2. Furthermore, following glutathione depletion, Bcl-2-overexpressing cells were sensitized to undergo cyanide m-chlorophenylhydrazone-induced apoptosis. These data suggest that the action of Bcl-2 is dependent, in part, on the cellular and mitochondrial redox state.

Inhibition of store-operated calcium entry in human lymphocytes by radiation: protection by glutathione.

The influence of gamma radiation on basal compared to activation-dependent Ca(2+) influx in human lymphocytes was investigated. A new quantitative fluorescence technique termed differential ratiometric fluorescence spectroscopy (DRFS) was employed. DRFS facilitated the real-time detection of changes in fluorescence in experimental and control cell samples simultaneously, enabling the resolution of acute moderate changes ( congruent with10-30%) in Ca(2+) (manganese) influx after exposure to ionizing radiation and other oxidant interventions. Exposure to radiation inhibited thapsigargin-stimulated store-operated Ca(2+) influx but not basal Ca(2+) influx in Jurkat T cells and human peripheral blood lymphocytes. The response of store-operated Ca(2+) influx to gamma radiation was dependent on dose between 5 and 40 Gy and was inhibited by preincubation with the Ca(2+) channel blocker Ni(2+), as determined with Jurkat T cells. Elevation of the intracellular concentration of glutathione significantly reduced the inhibition of Ca(2+) influx by gamma radiation. Similar to radiation, both the superoxide anion-generating xanthine/xanthine oxidase system and hydrogen peroxide inhibited thapsigargin-stimulated Ca(2+) influx in Jurkat T cells, and this inhibition was reversed in the presence of the antioxidant N-acetyl-l-cysteine. In conclusion, (1) ionizing radiation inhibited store-operated Ca(2+) entry in human lymphocytes, (2) the sensitivity of Ca(2+) influx to radiation was strictly dependent on depletion of Ca(2+) stores, and (3) glutathione protected against the inhibition of store-operated Ca(2+) entry by gamma radiation.

Intrathoracic desmoid at previous thoracotomy site.

Desmoid tumor (aggressive fibromatosis) of the chest wall is rare and usually extrathoracic. A large extrapleural intrathoracic desmoid occurred at the site of previous thoracotomy, and recurred five years later.

Multiple constrast injections in epidural venography.

Multiple contrast injections were necessary in 65% of the 140 epidural venograms performed at the Penobscot Bay Medical Center between January and December 1977. Several examples of the value of multiple injections are illustrated. Institutions interested in performing epidural venography or those performing the examination on a limited basis should be aware of the need for multiple injections, allowing time for reviewing the initial series of radiographs, for reloading the film changer and injector, and for repeating fluoroscopy and catheter manipulation.

Popliteal vein thrombosis secondary to popliteal artery aneurysm.

Two patients with popliteal vein thrombosis secondary to popliteal artery aneurysm are described. The association of venous abnormalities in 623 reported cases of popliteal artery aneurysm is reviewed. The high morbidity from popliteal vein thrombosis would seem to justify preoperative leg venography in patients with popliteal artery aneurysm.

Jejunal diverticulitis.

Two patients with jejunal diverticulitis are presented. Each demonstrated a wide spectrum of clinical and radiographic findings over several years. Radiographic abnormalities including incomplete jejunal obstruction, an omental mass displacing jejunal loops, leakage of barium into adjacent mesenteric abscess, and extrinsic serosal changes involving the transverse colon have permitted a correce preoperative diagnosis in each patient.

Outpatient arteriography at a small community hospital.

Most types of arteriographic procedures are performed on an outpatient basis at Knox County General Hospital. Four years of experience indicates no increased incidence of complications between the inpatient and outpatient groups. No patient had to be admitted to the hospital for delayed complications. Observation within the radiology department or short-stay recovery area for up to four hours seems adequate postarteriographic management and safely avoids routine overnight hospital admission.