Method of blood-gas interface control in surgical gas traps

• US 4,976,685 A
• Filed: 06/15/1988
• Issued: 12/11/1990
• Est. Priority Date: 06/15/1988
• Status: Expired due to Fees

• Current Assignee: Instrumentarium Dental Incorporated (Envista Holdings Corporation)
• Original Assignee: Frank E. Block Jr
• Inventors: Block, Frank E. Jr.
• Primary Examiner(s): Yasko, John D.
• Assistant Examiner(s): GUTOWSKI, ANTHONY
• Application Number:
  US07/207,333
• Time in Patent Office: 909 Days
• Field of Search: 604/5, 604/45, 604/49-53, 604/65, 604/113, 604/114, 604/122-127, 604/181, 604/93, 604/246, 604/248, 604/251-255, 604/140, 604/146, 604/183, 604/207, 604/280 , 604/284, 604/405, 604/415
• US Class Current: 604/522
• CPC Class Codes: A61M 5/1412 Burettes, measuring cylinders for laboratory use B01L3/02
• CPC Class Codes: A61M 5/36 with means for eliminating or preventing injection or infusion of air into body dialysis systems, blood oxygenators A61M1/14; haemofiltration equipment A61M1/34; automatic tube cut-off A61M39/281

Abstract

Blood is stored under refrigeration at a temperature of about 4° C. When it is utilized on a relatively rapid basis within a surgical theater it is transported by tubing through a blood warming apparatus which, while warming the blood, causes an outgasing of entrained air. This air is trapped in an air trap receptacle having a drip chamber within which a gas-blood interface is developed. To assure that the capacity of the trap is not exceeded, an improved technique of gas removal and interface level setting is provided wherein access is achieved essentially through the entrance region of the gas trap receptacle.

Claims

1. In a surgical procedure wherein a supply of blood is provided from refrigerated storage for infusive application to a patient through tubing extending from said supply to a warming device, and from said warming device to a location of administration to said patient, the method for removing gas products resulting from the operation of said warming device, comprising the steps of:

providing a gas trap having a substantially transparent side surface, a normally upwardly disposed entrance surface in fluid flow communication with a first length of said tubing downstream from said warming device and having a lower disposed surface spaced from said entrance surface to define a gas trap drip chamber of given volumetric capacity and in fluid flow communication with a second length of said tubing extending from said lower disposed surface to said location of administration;

flowing said blood from said supply through said warming device, thence through said gas trap to effect an accumulation of gas and blood therein to establish a blood surface-gas interface at given levels above said lower disposed surface but spaced below said entrance surface to provide an observable quantity of collected gas products;

providing a stopcock valve located next to said gas trap entrance surface having an externally accessible outlet port and manually actuable from a closed to an open position for forming a valve fluid passage path providing gas and liquid communication between said gas trap and said outlet port;

accessing said accumulation of gas when said interface level extends below an acceptable said given level by the removable insertion of the hollow stem component of a manually actuable syringe into said externally accessible outlet port; and

manually applying suction with said syringe at said valve fluid passage path to remove a portion of said accumulated gas of quantity sufficient to at least restore said acceptable level.

2. The method of claim 1 including the step of blocking said fluid flow communication at said first length of tubing during said step of manually applying suction at said valve fluid passage path.

3. The method of claim 1 in which said stopcock valve is fixed to and extends outwardly from said entrance surface next to said first length of tubing.

4. In a surgical procedure wherein a supply of liquid is provided from refrigerated storage for infusive application to a patient through tubing extending from said supply to a warming device and thence to a location of administration to said patient, the method for controlling the disposition of gas products resulting from the operation of said warming device, comprising the steps of:

providing a gas trap having an entrance surface with a normally upwardly disposed orientation in fluid flow communication with a first length of said tubing downstream from said warming device and having a lower disposed surface spaced from said entrance region to define a gas trap drip chamber for receiving said liquid and gas products and effecting an accumulation thereof in said chamber forming a gas-liquid interface at given levels above said exit surface, said chamber being substantially transparent and in fluid flow communication with a second length of said tubing extending from said lower disposed surface to said location of administration;

flowing said fluid from said supply through said warming device, thence through said gas trap chamber to effect said accumulation and establish said gas-liquid interface within said chamber at said given levels above said lower disposed surface but spaced below said entrance surface;

providing a stopcock valve located next to said gas trap entrance surface having an externally accessible outlet port and manually actuable from a closed to an open position for forming a valve fluid passage path providing gas and liquid communication between said gas trap and said outlet ports;

accessing said accumulation of gas products by the removable insertion of the hollow stem component of a manually actuable syringe into said externally accessible outlet port when said gas-liquid interface is at an unacceptable level within said chamber with a hypodermic syringe; and

manually applying air pressure selected in a range from negative-to-positive with said syringe at said valve fluid passage path in an amount effective to adjust said gas-liquid interface to an acceptable level while retaining said gas trap entrance surface in said normally upwardly disposed orientation.

5. In a surgical procedure wherein a supply of blood is provided from refrigerated storage for infusive application to a patient through tubing extending from said supply to a warming device, and from said warming device to a location of administration to said patient, the method for removing gas products resulting from the operation of said warming device, comprising the steps of:

providing a gas trap having a substantially transparent side surface, a normally upwardly disposed entrance surface in fluid flow communication with a first length of said tubing downstream from said warming device and having a lower disposed surface spaced from said entrance surface to define a gas trap drip chamber of given volumetric capacity and in fluid flow communication with a second length of said tubing extending from said lower disposed surface to said location of administration;

flowing said blood from said supply through said warming device, thence through said gas trap to effect an accumulation of gas and blood therein to establish a blood surface-gas interface at given levels above said lower disposed surface but spaced below said entrance surface to provide an observable quantity of collected gas products;

providing a stopcock valve located next to said gas trap entrance surface having a first fluid passage path communicating fluid between said warming device and said gas trap through said entrance surface and manually actuable to establish a second path providing gas and liquid communication between said gas trap and an externally accessible outlet port of said valve;

accessing said accumulation of gas by the removable insertion of the hollow stem component of a manually actuable syringe into said accessible outlet when said interface level extends below an acceptable said given level;

manually actuating said stopcock valve; and

manually applying suction to said second path to remove a portion of said accumulated gas of quantity sufficient to at least restore said acceptable level.