Human factors affect the quality of cardiopulmonary resuscitation in simulated cardiac arrests

Aim: Cardiopulmonary resuscitation is a team endeavour. There are only limited data on whether team performance during cardiopulmonary resuscitation is influenced by behavioural issues. The aim of the study was to determine whether and how human factors affect the quality of cardiopulmonary resuscitation. Methods: 16 teams, each consisting of three health-care workers, were studied in a patient simulator. A scenario of witnessed cardiac arrest due to ventricular fibrillation was used. Ventricular fibrillation could be converted into sinus rhythm by two countershocks administered during the first 2 min or by two countershocks administered during the first 5 min provided that uninterrupted basic life support was started in under 60 s. Teams were rated to be successful if ventricular fibrillation was converted into sinus rhythm. Behavioural rating included leadership, task distribution, information transfer, and conflicts. Results: Only six out of 16 teams were successful. Compared with successful teams, teams that failed exhibited significantly less leadership behaviour (P=0.033) and explicit task distribution (P=0.035). All teams shared among them sufficient theoretical knowledge to successfully treat the simulated cardiac arrest. Conclusions: In a scenario of simulated witnessed cardiac arrest almost two thirds of teams composed of qualified health-care workers failed to provide basic life support and/or defibrillation within an appropriate time window. Absence of leadership behaviour and absence of explicit task distribution were associated with poor team performance. Failure to translate theoretical knowledge into effective team activity appears to be a major problem.     

Inactivation of human immunodeficiency virus by gamma radiation and its effect on plasma and coagulation factors

The inactivation of HIV by gamma-radiation was studied in frozen and liquid plasma; a reduction of the virus titer of 5 to 6 logs was achieved at doses of 5 to 10 Mrad at -80 degrees C and 2.5 Mrad at 15 degrees C. The effect of irradiation on the biologic activity of a number of coagulation factors in plasma and in lyophilized concentrates of factor VIII (FVIII) and prothrombin complex was examined. A recovery of 85 percent of the biologic activity of therapeutic components present in frozen plasma and in lyophilized coagulation factor concentrates was reached at radiation doses as low as 1.5 and 0.5 Mrad, respectively. As derived from the first-order radiation inactivation curves, the radiosensitive target size of HIV was estimated to be 1 to 3 MDa; the target size of FVIII was estimated to be 130 to 160 kDa. Gamma radiation must be disregarded as a method for the sterilization of plasma and plasma-derived products, because of the low reduction of virus infectivity at radiation doses that still give acceptable recovery of biologic activity of plasma components.     

Resolution of infection status of human immunodeficiency virus (HIV)- seroindeterminate donors and high-risk seronegative individuals with polymerase chain reaction and virus culture: absence of persistent silent HIV type 1 infection in a high-prevalence area

To address concerns over the prevalence of silent (antibody-negative) infections among blood donors and high-risk populations, a combination of proviral amplification by polymerase chain reaction (PCR) and viral isolation by co-culture techniques was employed to resolve the human immunodeficiency virus type 1 (HIV-1) infection status of well-characterized groups of suspect blood donors and others identified in the blood bank setting. No silent infections were found in 65 follow-up samples from 26 persistently HIV-1-seroindeterminate blood donors, 16 persistently seronegative heterosexual partners of infected transfusion recipients, and 6 high-risk seronegative homosexual men identified through donor look-back investigations. In contrast, 21 seropositive controls tested positive. These results suggest a low prevalence of persistently silent infections in at-risk populations, even in high HIV prevalence regions. The PCR assay, with a co-detected internal positive control, and appropriate confirmatory algorithms, was found to be a useful direct assay to rule out infection, especially in concert with confirmatory virus isolation.     

Effect of tecarfarin,a novel vitamin K epoxide reductase inhibitor,on coagulation in beagle dogs

Background and purpose:

Tecarfarin (ATI-5923) is a novel vitamin K epoxide reductase inhibitor that is metabolized by esterase (mainly human carboxylesterase 2) to a single major metabolite, ATI-5900, in rats, dogs and humans. Tecarfarin is not significantly metabolized by CYP450 enzymes. The objective of this study was to test and compare the efficacy of tecarfarin with that of warfarin, when administered either intravenously or once a day orally, to produce stable anticoagulation in beagle dogs.

Experimental approach:

Effects on coagulation were assessed by measuring the activity levels of Factor VII and Factor X and thromboplastin-induced coagulation times, reported as prothrombin time (PT).

Key results:

Continuous intravenous infusions and oral administration of tecarfarin and warfarin caused a dose-dependent decrease in activity of Factor VII and Factor X, and associated increase in PT. Intravenous fresh frozen canine plasma or subcutaneous vitamin K₁ treatment reversed the anticoagulant effects of orally administered tecarfarin. Consistent with the inhibitory effects of amiodarone on CYP2C9, co-administration of amiodarone significantly increased the anticoagulation effect of warfarin and plasma warfarin concentrations. In contrast, amiodarone had no effect on the anticoagulation induced by tecarfarin or tecarfarin plasma concentrations in this model.

Conclusions and implications:

Overall, the data presented herein indicate that tecarfarin, via a vitamin K-dependent mechanism, causes changes in key parameters of haemostasis in beagle dogs that are consistent with effective anticoagulation. Compared to warfarin it has a decreased potential to interact metabolically with drugs that inhibit CYP450 enzymes and, therefore, may offer an improved safety profile for patients.     

Development of the Manchester framework for the evaluation of emergency department pharmacy services

International Journal of Clinical Pharmacy - Many countries, including the United Kingdom, have established Emergency Department (ED) pharmacy services where some ED pharmacists now work as...