The right supraclavicular fossa ultrasound view for correct catheter tip positioning in right subclavian vein catheterisation: a prospective observational study.

Central venous catheter misplacement is common (approximately 7%) after right subclavian vein catheterisation. To avoid it, ultrasound-guided tip navigation may be used during the catheterisation procedure to help direct the guidewire towards the lower superior vena cava. We aimed to determine the number of central venous catheter misplacements when using the right supraclavicular fossa ultrasound view to aid guidewire positioning in right infraclavicular subclavian vein catheterisation. We hypothesised that the incidence of catheter misplacements could be reduced to 1% when using this ultrasound technique. One -hundred and three adult patients were prospectively included. After vein puncture and guidewire insertion, we used the right supraclavicular fossa ultrasound view to confirm correct guidewire J-tip position in the lower superior vena cava and corrected the position of misplaced guidewires using real-time ultrasound guidance. Successful catheterisation of the right subclavian vein was achieved in all patients. The guidewire J-tip was initially misplaced in 15 patients, either in the ipsilateral internal jugular vein (n = 8) or in the left brachiocephalic vein (n = 7). In 12 patients it was possible to adjust the guidewire J-tip to a correct position in the lower superior vena cava. All ultrasound-determined final guidewire J-tip positions were consistent with the central venous catheter tip positions on chest X-ray. Three out of 103 catheters were misplaced, corresponding to an incidence (95%CI) of 2.9 (0.6-8.3) %. Although the hypothesis could not be confirmed, this study demonstrated the usefulness of the right supraclavicular fossa ultrasound view for real-time confirmation and correction of the guidewire position in right infraclavicular subclavian vein catheterisation.

Effect of EACA, PAMBA, AMCA and AMBOCA on fibrinolysis induced by streptokinase, urokinase and tissue activator.

A study is presented in which the inhibiting effects of eACA, PAMBA, AMCA and AMBOCA on fibrinolysis induced by three activators have been compared by a clot lysis method. The order of inhibitory potency was AMBOCA greater than AMCA greater than PAMBA greater than EACA. The activity ratios obtained were found to be influenced by the level of inhibition. At low levels of inhibition the differences between the inhibitory activities are usually more pronounced than at high levels. The degree of inhibition is dependent on the fibrinolytic activator used. The order of sensitivity to the inhibitors was, within the analytical conditions used, found to be: tissue activator greater than streptokinase greater than urokinase. The results are discussed in comparison to the different activity ratios reported by others.

Separation of herpes simplex virus virions and nucleocapsids on Percoll gradients.

Herpes simplex virus (HSV) virions and nucleocapsids were separated and purified by centrifugation in density gradient of polyvinylpyrrolidone-coated colloidal silica (Percoll). Virions and nucleocapsids banded at densities of 1.07 and 1.03 g/ml, respectively. The distribution in the gradient of virions and nucleocapsids suggested that particles were discriminated according to difference in size rather than in density. The reduction of cell proteins in preparations of purified virions was 1300--2100 times. The recovery of infective virus was approximately 30%.