Combination blood sampling and intravenous infusion apparatus and method

In combination, apparatus adapted to supply an intravenous solution to a patient, to allow periodic blood sampling and to allow periodic administering of liquid medicine, comprising

• a three-way valve having an intravenous fluid infusion port, a flushing syringe port and an outlet line
• a blood sampling medical fluid injection site means connected to said outlet line of the three-way valve for alternatively sampling a patient's blood or injecting a liquid medicine into said patient
• said site means connection to said outlet line of the three-way valve comprising a rigid connection and said site means being integrally connected to said three-way valve
• said site means comprising an opening having a diaphragm extending thereacross and sealingly attached thereto, said diaphragm being of a height whereby a bottom surface thereof is substantially aligned with an internal diametrical surface to which said opening is connected.

A method for taking a sample of a patient's blood while the patient is being administered an intravenous solution comprising the steps of

• inserting a catheter into a patient, said catheter being connected by flexible tubing to a combination three-way valve having a blood sampling site rigidly connected downstream thereto, said sampling site having a flexible diaphragm with an inner end being substantially in alignment with an inner diameter of an outlet port of the three-way valve, the three-way valve having an inlet port connected to a supply of intravenous fluid and a third port connected to a flushing syringe
• operating the catheter apparatus such that the intravenous fluid is being administered to the patient
• shutting off the flow from the intravenous fluid supply
• operating the flushing syringe drawing into the flushing syringe all the intravenous fluid from the patient to the third port of the three-way valve until such time as the patient's blood is being drawn into the flushing syringe
• inserting a blood sampling into the blood sampling site and drawing a blood sample
• withdrawing the blood sampling syringe from the blood sampling site
• re-operating the flushing syringe in a reverse direction so as to cause the blood and intravenous fluid therein to fill the line between the third port of the three-way valve and the patient, then
• opening the three-way valve to continue administering the intravenous fluid.

A method for injecting a medicinal fluid into a patient when the patient is being administered an intravenous fluid comprising the steps of

• inserting a catheter into a patient, said catheter being connected by a flexible tubing to a combination three-way valve having an injection site rigidly connected downstream thereto, an injection site having a flexible diaphragm with an inner end being substantially in alignment with an inner diameter of an outlet port of the three-way valve, an inlet port of the three-way valve being connected to a supply of intravenous fluid, and a third port of the three-way valve being connected to a flushing syringe filled with a saline fluid
• operating the catheter apparatus such that the intravenous fluid is being administered to the patient
• shutting off the flow from the intravenous fluid supply
• operating the flushing syringe so as to inject some of the saline fluid in the flushing syringe from the third port of the three-way valve into the patient
• inserting a syringe filled with a medicinal fluid into the injection site
• operating the syringe filled with medicinal fluid until the same is injected into the patient and into the line from the patient to the injection site
• removing the injection syringe from the injection site, and
• opening the three-way valve so as to continue administering the intravenous fluid to the patient.