Science of perception, decision making and fatigue in the maritime industry.

In this paper, we investigate how perception, decision making and fatigue affect safety in the maritime industry. With maritime safety incidents often having disastrous effects on the lives of the seafarers, the natural environment, and the industry as a whole, a better understanding of the science behind the human errors is necessary to increase safety at sea. We conducted interviews and real time observations of seafarers, and we combine our findings with a review of relevant academic literature with the aim of using scientific knowledge to address a real-world problem. We conclude that the seafarers consistently work at the limits of their cognitive abilities and that better care for their wellbeing is crucial for safety at sea. It is hoped that this study will be beneficial to the practitioners in the field of the maritime industry as well as psychologists studying the effects of long term, high cognitive loads in the work environment.

Analysis of the third- and fourth-generation cephalosporin use for the treatment of infections caused by Gram-negative bacteria in hospital settings.

OBJECTIVE: The aims of our study were to assess the prevalence and distribution of Gram-negative (G-) bacteria in hospital isolates, their sensitivity to the third- and fourth-generation cephalosporins (c3 and c4), therapeutic use of c3 and c4 in the treatment of G- infections and drug utilisation data. RESEARCH DESIGN AND METHODS: This cross-sectional study collected medical records data from the General Hospital "Gornji Milanovac" (GM) and the University Medical Center "Bezanijska kosa" (BK). The time frame of the study was 12 months. Microbiological and clinical parameters, and c3/c4 drug utilisation were analysed. RESULTS: Escherichia coli were the most predominant pathogen in GM and BK, accounting for 43% and 28% of all G- isolates, respectively (GM), 884 G- isolates obtained from 606 patients; BK, 1766 isolates obtained from 1045 patients). Nearly half of the isolates (55% and 43%) were obtained from urine samples collected from the surgical ward (GM), and the internal medicine wards and intensive care unit (BK). On average, the resistance rate of G- strains against c3 and c4 reached 40% and 70%, respectively (lowest in E. coli, 8%-25%; highest in Acinetobacer baumannii, 67%-100%). Resistance rate of Pseudomonas spp. to cefepime and ceftazidime was low/moderate (0%-30% and 19%-47%). In BK, the adult patients were older than in GM (75 vs 66 years), with longer hospital stay (19 vs 10 days) and bacteria were isolated later during hospitalisation (10 vs 2 days). C3 and c4 were more often used in empirical therapy (83% vs 64%) in BK. Ceftazidime and cefepime were used more often in BK than in GM (2.036 vs 69 DDD/y and 586 vs. 126 DDD/y, respectively). CONCLUSION: The use of c3 and c4 in the treatment of G- infections in both hospitals should be re-evaluated in accordance with current guidelines and local resistance.

Nosocomial coagulase-negative staphylococci in Belgrade: between Scylla and Charybdis.

INTRODUCTION: Coagulase-negative staphylococci (CoNS) are increasingly resistant nosocomial pathogens. We aimed to analyze the prevalence of CoNS isolates in clinical settings, the evolution of antimicrobial resistance of CoNS, and antibiotic consumption in a hospital. METHODOLOGY: This retrospective cohort study was carried out at a tertiary healthcare facility over 17 months. Identification of isolated cultures and antibiotic susceptibility testing were performed using the Vitek2 system. Of 1,217 isolates, 209 were obtained from 193 patients who had symptoms of nosocomial infections. Data were analyzed by descriptive statistics. Antibiotic consumption in the hospital is expressed in defined daily doses/100 patient days. RESULTS: Sixty-one percent of patients were admitted to the internal medicine ward, while others were admitted to the surgical ward. Forty-four percent of Gram-positive isolates were from wound swabs, and 26% were from blood. The predominant Gram-positive bacteria were CoNS. Antibiotic resistance of CoNS was highest against beta-lactam antibiotics, macrolides, and tetracyclines. Tigecycline, linezolid, and vancomycin produced the highest activities against CoNS in in vitro conditions, and consumption of linezolid and tigecycline increased in the same period. CONCLUSION: There are just a few remaining therapeutic options for the treatment of CoNS according to our results; vancomycin, linezolid, and tigecycline might be considered as first-choice antibiotics, but such a hypothesis should be supported with a pharmacoeconomic analysis. Unfortunately, novel antimicrobial agents are still unavailable and/or too expensive in developing countries. However, inappropriate use of those antibiotics may lead to the rapid development of resistant strains in the near future.

Factors affecting the development of adverse drug reactions to ß-blockers in hospitalized cardiac patient population.

The aim of the present study was to undertake a study on the prevalence of cytochrome P450 2D6 (CYP2D6) poor metabolizer alleles (*3, *4, *5, and *6) on a Montenegrin population and its impact on developing adverse drug reactions (ADRs) of ß-blockers in a hospitalized cardiac patient population. A prospective study was conducted in the Cardiology Center of the Clinical Center of Montenegro and included 138 patients who had received any ß-blocker in their therapy. ADRs were collected using a specially designed questionnaire, based on the symptom list and any signs that could point to eventual ADRs. Data from patients' medical charts, laboratory tests, and other available parameters were observed and combined with the data from the questionnaire. ADRs to ß-blockers were observed in 15 (10.9%) patients. There was a statistically significant difference in the frequency of ADRs in relation to genetically determined enzymatic activity (P<0.001), with ADRs' occurrence significantly correlating with slower CYP2D6 metabolism. Our study showed that the adverse reactions to ß-blockers could be predicted by the length of hospitalization, CYP2D6 poor metabolizer phenotype, and the concomitant use of other CYP2D6-metabolizing drugs. Therefore, in hospitalized patients with polypharmacy CYP2D6 genotyping might be useful in detecting those at risk of ADRs.

Nosocomial Infections Caused by Acinetobacter baumannii: Are We Losing the Battle?

BACKGROUND: The incidence of nosocomial infections caused by multi-drug- and extended-drug resistant strains of Acinetobacter is constantly increasing all over the world, with a high mortality rate. We analyzed the in-hospital data on the sensitivity of Acinetobacter baumannii isolates and correlated them with antibiotic treatment and clinical outcomes of nosocomial infections over a 17-mo period. METHODS: Retrospective analysis was performed at the Clinical Center "Bezanijska kosa," Belgrade, Serbia. Microbiologic data (number and sensitivity of A. baumannii isolates) and clinical data (medical records of 41 randomly selected patients who developed nosocomial infection caused by A. baumannii) were matched. RESULTS: Acinetobacter baumannii, detected in 279 isolates and obtained from 19 patients (12% of all samples), was resistant to almost all antibiotics tested, including carbapenems, with the exception of colistin and tigecycline. It was obtained most often from the respiratory tract samples. Empiric treatment of the nosocomial infections (pneumonia in 75% of cases) involved cephalosporins, metronidazole, and carbapenems (80%, 66%, and 61% of patients, respectively), whereas tigecyclin and colistin were used primarily in targeted therapy (20% and 12% of patients, respectively). The mortality rate of patients treated empirically was significantly higher (p < 0.01), reaching 100% in the elderly. CONCLUSIONS: Nosocomial A. baumannii infections represent a significant clinical problem because of their high incidence, lack of susceptibility to the most commonly used antibiotics, and the often inappropriate treatment, which favors the development of multi-drug-resistant strains.

Sustained increase in platelet aggregation after the cessation of clopidogrel.

This study shows that the abrupt cessation of one-year clopidogrel treatment was not associated with thrombotic events in a prospective, multicentre study that enrolled 200 patients subjected to coronary stent implantation and treated with aspirin + clopidogrel 1 year after the stent placement. The aim of the study was to investigate the causes of a sustained increase of platelet aggregability, considering that the values of platelet aggregation stimulated with ADP + PGE1 (ADPHS values) significantly increased 10-90 days after the cessation of clopidogrel. Values of platelet aggregation induced by thrombin receptor activating peptide (TRAP values) and arachidonic acid (ASPI values) were divided into quartiles on the basis of ADPHS values 10 days after stopping clopidogrel (ADPHS10 ). There was a significant difference between TRAP values divided into quartiles according to ADPHS10 , 10, 45 and 90 days after stopping clopidogrel (P < 0.001, all), and ASPI values across the same quartiles 10 and 45 days after the cessation of clopidogrel (P = 0.028 and 0.003). The results of the study indicate that patients with early pronounced rebound phenomena to clopidogrel termination have a long-term (at least 90 days) increased platelet aggregation to other agonists such as thrombin-related activated protein and arachidonic acid, suggesting the complex mutual relationship of various factors/agonists influencing the function of platelets.

Men with lower HDL cholesterol levels have significant increment of soluble CD40 ligand and high-sensitivity CRP levels following the cessation of long-term clopidogrel therapy.

AIM: The aim of this study was to examine whether the termination of long-term clopidogrel therapy results in a proinflammatory state and whether lipid parameters influence the inflammatory response after stopping the drug. METHODS: A prospective, multicenter study was conducted among 200 patients with implanted coronary stents who received dual antiplatelet therapy for one year, without ischemic or bleeding events. According to the guidelines, clopidogrel was discontinued after one year. In all patients, the high-sensitivity C-reactive protein (hsCRP), soluble CD40 ligand (sCD40L) and lipid [total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C)] levels were measured twice: on the day of cessation of clopidogrel and 45 days after the termination of clopidogrel treatment. RESULTS: In men (n=151), the sCD40L serum levels were significantly higher 45 days after the discontinuation of clopidogrel (p=0.007), while the hsCRP levels were not significantly different (p=0.407). Furthermore, when analyzed across the HDL-C quartiles, the hsCRP and sCD40L values were found to be associated with the levels of HDL-C after the discontinuation of clopidogrel in men. In addition, the men in the first HDL-C quartile exhibited the most pronounced increase in the sCD40L levels (p=0.001) and had significantly higher hsCRP levels (p=0.001) compared to the subjects in the other quartiles. Other lipid parameters did not show any associations with the sCD40L or hsCRP levels. CONCLUSIONS: The discontinuation of clopidogrel is associated with higher increments in the sCD40L level, and a pronounced proinflammatory response is associated with a lower HDL-C concentration.

Time-dependent changes of plasma adiponectin concentration in relation to coronary microcirculatory function in patients with acute myocardial infarction treated by primary percutaneous coronary intervention.

BACKGROUND AND PURPOSE: To analyze plasma adiponectin kinetics in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (pPCI) and its association with coronary flow reserve (CFR), an index of coronary microcirculatory function. METHODS: A total of 96 consecutive patients with the first anterior STEMI treated by pPCI without heart failure were included. CFR was assessed on the 7th day after pPCI. Plasma adiponectin was measured on admission before pPCI, and on the 2nd and 7th day after pPCI. RESULTS: Adiponectin concentration was the highest on admission, declined to the lowest level on the 2nd day, and rose on the 7th day remaining below admission values. Impaired coronary microcirculatory function (CFR<2) was observed in 41% of the patients. Adiponectin concentrations significantly positively correlated with CFR, and the strongest correlation was with the 2nd day adiponectin (r=0.489, p<0.001). In multivariate models, adiponectin concentrations were independent predictors of impaired CFR [on admission: odds ratio (OR) 0.175, confidence interval (CI): 0.047-0.654, p=0.010; 2nd day: OR 0.146, 95% CI: 0.044-0.485, p=0.002; 7th day: OR 0.198, CI: 0.064-0.611, p=0.005]. The best power to predict impaired CFR was the 2nd day adiponectin. Delta values of adiponectin (differences between adiponectin concentrations) did not correlate with CFR. CONCLUSIONS: In patients with the first anterior STEMI treated by pPCI plasma adiponectin concentrations before and after pPCI are strongly associated with CFR. Our results support the hypothesis that low adiponectin, especially during the early post-pPCI period, carries the risk for impaired coronary microcirculatory function in STEMI patients.

Coronary flow of the infarct artery assessed by transthoracic Doppler after primary percutaneous coronary intervention predicts final infarct size.

Coronary microcirculatory function after primary percutaneous coronary intervention (pPCI) in patients with acute myocardial infarction is important determinant of infarct size (IS). Our aim was to investigate the utility of coronary flow reserve (CFR) and diastolic deceleration time (DDT) of the infarct artery (IRA) assessed by transthoracic Doppler echocardiography after pPCI for final IS prediction. In 59 patients, on the 2nd day after pPCI for acute anterior myocardial infarction, transthoracic Doppler analysis of IRA blood flow was done including measurements of CFR, baseline DDT and DDT during adenosine infusion (DDT adeno). Killip class, myocardial blush grade, resolution of ST segment elevation, peak creatine kinase-myocardial band and conventional echocardiographic parameters were determined. Single-photon emission computed tomography myocardial perfusion imaging was done 6 weeks later to define final IS (percentage of myocardium with fixed perfusion abnormality). IS significantly correlated with CFR (r = -0.686, p < 0.01), DDT (r = -0.727, p < 0.01), and DDT adeno (r = -0.780, p < 0.01). CFR and DDT adeno in multivariate analysis remained independent IS predictors after adjustment for other covariates and offered incremental prognostic value in models based on conventional clinical, angiographic, electrocardiographic and enzymatic variables. In predicting large infarction (IS > 20 %), the best cut-off for CFR was <1.73 (sensitivity 65 %, specificity 96 %) and for DDT adeno ≤720 ms (sensitivity 81 %, specificity 96 %). CFR and DDT during adenosine are independent and powerful early predictors of final IS offering incremental prognostic information over conventional parameters of myocardial and microvascular damage and tissue reperfusion.

Acute insulin resistance in ST-segment elevation myocardial infarction in non-diabetic patients is associated with incomplete myocardial reperfusion and impaired coronary microcirculatory function.

BACKGROUND: Insulin resistance (IR) assessed by the Homeostatic Model Assessment (HOMA) index in the acute phase of myocardial infarction in non-diabetic patients was recently established as an independent predictor of intrahospital mortality. In this study we postulated that acute IR is a dynamic phenomenon associated with the development of myocardial and microvascular injury and larger final infarct size in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (pPCI). METHODS: In 104 consecutive patients with the first anterior STEMI without diabetes, the HOMA index was determined on the 2nd and 7th day after pPCI. Worst-lead residual ST-segment elevation (ST-E) on postprocedural ECG, coronary flow reserve (CFR) determined by transthoracic Doppler echocardiography on the 2nd day after pPCI and fixed perfusion defect on single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) determined six weeks after pPCI were analyzed according to HOMA indices. RESULTS: IR was present in 55 % and 58 % of patients on day 2 and day 7, respectively. Incomplete post-procedural ST-E resolution was more frequent in patients with IR compared to patients without IR, both on day 2 (p = 0.001) and day 7 (p < 0.001). The HOMA index on day 7 correlated with SPECT-MPI perfusion defect (r = 0.331), whereas both HOMA indices correlated well with CFR (r = -0.331 to -0.386) (p < 0.01 for all). In multivariable backward logistic regression analysis adjusted for significant univariate predictors and potential confounding variables, IR on day 2 was an independent predictor of residual ST-E ≥ 2 mm (OR 11.70, 95% CI 2.46-55.51, p = 0.002) and CFR < 2 (OR = 5.98, 95% CI 1.88-19.03, p = 0.002), whereas IR on day 7 was an independent predictor of SPECT-MPI perfusion defect > 20% (OR 11.37, 95% CI 1.34-96.21, p = 0.026). CONCLUSION: IR assessed by the HOMA index during the acute phase of the first anterior STEMI in patients without diabetes treated by pPCI is independently associated with poorer myocardial reperfusion, impaired coronary microcirculatory function and potentially with larger final infarct size.

Abrupt cessation of one-year clopidogrel treatment is not associated with thrombotic events.

We aimed to examine the rate of thrombotic events after discontinuation of one year clopidogrel therapy in patients with implanted coronary stent, and to determine platelet aggregability by multiple electrode analyzer after cessation of clopidogrel. This prospective, multicenter study enrolled 200 patients subjected to coronary stent implantation and treated with aspirin + clopidogrel one year after the stent placement. Platelet aggregation was measured using 3 agonists [adenosine diphosphate with PGE(1) (ADPHS), arachidonic-acid (ASPI), and thrombin receptor activating peptide (TRAP)] on the day of cessation of clopidogrel and at 10, 45, and 90 days after clopidogrel was stopped. Two thrombotic events were registered during the 6-months follow up (one ischemic stroke and one myocardial infarction; incidence of 1%). The mean values of ADP + PGE(1)- and ASPI-induced aggregation 10 - 90 days after the cessation of clopidogrel were significantly higher than values obtained before the termination of the drug (P < 0.001, all). Cessation of clopidogrel did not influence the TRAP-induced aggregation, which reached the plateau in all measurements. In conclusion, the incidence of thrombotic events after the cessation of one-year clopidogrel treatment might be lower than expected in patients with implanted coronary stent.

PCI and clopidogrel: antiplatelet responsiveness and patient characteristics.

OBJECTIVE: This study on responsiveness to clopidogrel and aspirin evaluates its interaction with: (i) patient characteristics; (ii) procedure characteristics; (iii) antiplatelet dose. METHODS AND RESULTS: After elective PCI, 60 patients receiving aspirin 100 mg daily, and clopidogrel 75 mg daily were monitored with the PFA 100 test and VASP assay. Non-responsiveness to aspirin and clopidogrel was found in 23 (38%) and 18 (30%) of 60 patients, respectively. Seven (12%) patients were dual nonresponders. Non-responders to both aspirin and clopidogrel were more often smokers. Non-responders to clopidogrel, in addition had elevated inflammatory markers (P < 0.05). Dual non-responders had (i) a higher platelet count, LDL, and CRP; (ii) a lower HDL (P < 0.05). Clopidogrel non-responders were receiving 150 mg clopidogrel, with a positive response in 72%. Eighty % of non-responders to 150 mg clopidogrel were also non-responders to aspirin. CONCLUSION: Baseline patient characteristics and clopidogrel dose modify the antiplatelet response. Also, patients resistant to both aspirin and clopidogrel do no benefit from an increased clopidogrel dose.

Thienopyridine resistance among patients undergoing intracoronary stent implantation and treated with dual antiplatelet therapy: assessment of some modifying factors.

In this open, prospective study we assessed the prevalence of antiplatelet resistance among patients subjected to intracoronary stent implantation. In patients treated with aspirin + thienopyridine (N = 32), platelet reactivity index (PRI) significantly decreased after 2 and 7 days of dual antiplatelet treatment in comparison with the same patients on aspirin monotherapy (P<0.001, both). After 7 days of aspirin + thienopyridine treatment, insufficient antiplatelet response was observed in 28% (9/32) of the patients. High interindividual variability in response to aspirin + thienopyridine treatment emphasizes the significance of thienopyridine resistance, while the influence of statins on such a treatment should be reassessed.