Safety Vent Research Articles

AIR PRESSURE IN BLOOD TRANSFUSIONS

To the Editor:— I am writing to protest the editorial inThe Journal, July 2, page 1032, entitled Use of Air Pressure to Speed up Blood Transfusion. Since the editorial is unsigned, I do not know its source, but I would hazard the guess that the writer has never been faced with the problem of the rapid administration of large amounts of bank blood. He comments that he was unaware of the fact that the transfusion of blood under air pressure is still in common use. I am sure there is no institution where radical surgery is performed that does not use blood under air-positive pressure. Also, the author does not seem to understand that there is usually a safety vent trap bottle of saline solution interposed between the blood which is being subjected to the air pressure and the direct line to the patient. The recommendation from such an

A Nasal Aspirator for Home Use

A nasal aspirator is now available based upon the Venturi principle of water pressure suction. By means of simple adaptors this apparatus may be easily attached to kitchen water faucets in more than than 90% of homes. It has a long plastic hose and plastic, bulb-type nasal tip designed to fit securely in the ostia of the nose. The nasal tip has a safety vent on time side so that pressure can be controlled easily by the finger.[See figure in source pdf.] This aspirator is inexpensive.

Further simplifying intestinal intubation: An in vivo and in vitro study

One of the most important complications incidental to the use of the single lumen intestinal decompression tube is the permeation of intestinal gases into the lumen of the balloon of such tubes. Various methods have been proposed to prevent this complication. None of the methods heretofore proposed provided a simple but absolutely effective prevention. The use of a stylet inserted through the most distal hole and then the application of a tight tie over the tube at this point followed with the removal of the stylet provided a good safety valve vent. However, a certain nicety in judgment as to exactly how tight this tie should be tied resulted in two types of error, namely, if tied too loosely, the mercury would escape; if tied too tightly, no safety vent would be formed. As a result of m vitro and in viro experiments a further simplification of an already simplified tube was made possible. In this newer tube the end of a simple tube was completely sealed off. The balloon is then applied to the end of the tube. This creates a simplified radiopaque tube without any metal parts and tipped by a simple neoprene rubber balloon. (Cantor tube, Fig. 6.) The required amount of mercury is then injected into the balloon through a 21 gauge needle after which all the air is aspirated. Thus in one procedure the mercury is injected, a hole is made in the balloon to act as a safety vent and the air remaining within the balloon is aspirated. Because the end of the tube is sealed, no mercury can leak out with proper handling. The perforation of the wall of the balloon by the 21 gauge needle has been shown in vitro and in vivo to prevent overdistention of such balloons by any gas. A smaller caliber needle than a 21 gauge would not make a perforation large enough, whereas a larger caliber needle than a 21 gauge would make a hole so large that mercury would leak out. The 21 gauge needle was found experimentally to be the ideal size for this purpose since the hole it makes is large enough to permit a rapid loss of gas within the balloon and yet the vent is small enough to prevent mercury from leaking if the perforation is not stretched during the insertion of the balloon into the nose.