title: Comparison of flow rates into vented and non-vented urinary drainage bags: possible relevance to infection.
abstract: Tests on vented and non-vented urinary drainage bags were carried out to establish if differences existed in the flow of fluid into them and whether air bubbles and air trapping were affected by venting. At flow rates of 3-12 ml sec-1 there was consistent flow into the vented bag until it was full. There was no air trapping in the bag, and no retrograde flow of air bubbles or fluid up the tube. Flow rates into non-vented bags were strongly affected by air in the drainage tube but, if this cleared, the flow rate was high until the bags were nearly full, at which time air was pushed into the tube. If air remained in the tube the flow rate was reduced. The non-vented bags required a higher pressure in the drainage tube to fill them than the vented bags, and allowed air bubbles to ascend from the bag up the drainage tube.
mesh_terms: D011312:Pressure; D014546:Urinary Catheterization / Q000295:instrumentation*