Effects of tube size for drainage on flow rate of different kinds of fluid studied in vitro / 中华急诊医学杂志

ABSTRACT

Objective To determine the appropriate size of the tube for the thoracic drainage in good efficiency by the experimental study in the influence of the tube size on the flow rate of the fluid with different properties.Methods Three groups were divided according to the different components in the fluidgroup A,whole blood with 30％ hematocrit; group B,2.5％ albumin solution; and group C,0.9％ normal saline.The total volume of the fluid was 1000 mL in each group in the experiment.Different sorts of fluids were drained with the chest tubes with different diameters (6F,8F,10F,12F,14F,16F,18F,20F,22F,24F,26F,28F,30F,32F,34F,36F of French F) separately,and the flow rate was calculated.ANOVA was used for the comparison of the differences in flow rate among the groups with given fluid property.Twofactor analysis of variance was used for the analysis of flow rates of fluid with different fluid properties.Curve fitting was performed according to the Poiseuille formula.Results The flow rate was positively correlated with the size of the chest drainage tube.The difference in flow rate among the tubes with difference in size was statistically significant (P ＜ 0.05) but there was no noticeable difference in flow rate between 6F and 8F (P =0.513).The flow rate of the 6F and 8F tubes was higher than that of the control (3.33 mL/min) but there was no significant difference between them (P ＞ 0.05).The flow rate of the tubes in 10F and above was obviously higher than that of control (P ＜ 0.05).The curve was estimated that group A was Q =0.002 9x4,R2 =0.991; group B Q=0.003 2x4,R2 =0.981; group C Q =0.003 4x4,R2 =0.975.When the flow rate was fixed at 3.33 mL/min,the estimated curve in group A was X ≈ 5.82F.Conclusions Our experiment indicated that the chest tube with small diameters (6F-14F) could meet the demand of high efficient drainage in the patients with hemothorax or pleural effusion.