Study objective: To investigate the effects of
streptokinase and deoxyribonuclease (DNase) on the viscosity of pus to
assess whether the DNase in the old preparation of
streptokinase-streptodornase used intrapleurally to treat empyema was
contributing to easier drainage of pus compared with purified
measurement of pus viscosity.
Patients: Pus from three
patients with surgically drained soft tissue abscesses and from six
patients with empyema thoracis of varying etiology was studied.
Interventions: Pus samples were incubated with saline
solution as control and with streptokinase,
streptokinase-streptodornase, human recombinant DNase, and a mixture of
streptokinase and DNase in concentrations approximating those achieved
in clinical practice.
Results: Purified streptokinase
had little effect on pus viscosity, with a mean reduction of 11.1% in
the surgical specimens and 1.7% in the empyema samples.
Streptokinase-streptodornase reduced viscosity by a mean of 52.8% in
the surgical samples and 94.8% in the empyema samples. Human
recombinant DNase reduced viscosity by a mean of 32.79% in surgical
samples and 93.4% in empyema samples. Adding streptokinase to human
recombinant DNase produced no further reduction in viscosity. Final
viscosities in samples treated with DNase were very similar whatever
the starting viscosity.
significantly reduces pus viscosity, whereas streptokinase has little
or no effect, and in empyema may work simply by breaking down
loculations. Clinical studies should be undertaken to see if these
in vitro changes produce clinical benefits. The simple
viscometer devised for these experiments may also prove useful in other