Patient warming methods

• US 5,279,598 A
• Filed: 05/12/1992
• Issued: 01/18/1994
• Est. Priority Date: 07/24/1991
• Status: Expired due to Fees

• Current Assignee: Charles M. Sheaff
• Original Assignee: Charles M. Sheaff
• Inventors: Sheaff, Charles M.
• Primary Examiner(s): Isabella, David
• Assistant Examiner(s): ZUTTARELLI, ANTHONY
• Application Number:
  US07/881,757
• Time in Patent Office: 616 Days
• Field of Search: 604/4-6, 604/291, 604/317, 604/318, 604/52, 604/53, 604/82, 604/83, 604/93, 604/96, 604/100, 604/102, 604/113, 604/264, 604/266, 422/44, 422/46, 128/692, 128/399
• US Class Current: 604/290
• CPC Class Codes: A61M 2205/3626 by controlled mixing of fluids at different temperatures
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 25/00 Catheters; Hollow probes dilators A61M29/00; peritoneal catheters A61M1/285; tracheal tubes A61M16/04; for drainage A61M27/00; for uterus, vagina or rectum A61M31/00 ; for measuring or testing A61B; materials for catheters A61L29/00
• CPC Class Codes: A61M 5/44 having means for cooling or heating the devices or media

Abstract

A patient warming method and apparatus including a catheter which mixes relatively hot intravenous fluids with the patient'"'"'s blood without excessive tissue damage, by monitoring the temperature of the mixed blood and the core temperature of the patient. The fluids are heated to about 50°-100° C. The catheter is surrounded by a relatively large diameter introducer sheath, and is spaced from the sheath by a cooling jacket. Unheated fluid is passed through the cooling jacket to thermally isolate the heated infusate from the patient, to prevent entry site and endothelial burning. An external computer control system monitors and controls both the body core temperature of the patient and the temperature and flow rate of the infusate.

Claims

1. A method for warming a patient with heated fluids at a controlled temperature and flow rate, the patient having blood which circulates within endothelial lined vessels, the patient'"'"'s blood having a core temperature inside the patient and a vessel temperature inside a selected endothelial lined vessel, comprising the steps of:

injecting heated fluids having a predetermined temperature of about 50°

-100°

Celsius into the selected vessel of the patient through an opening in the patient at a predetermined flow rate;

mixing the heated fluids with the blood, causing an increase in the vessel temperature, without excessive endothelial damage,

thermally isolating the opening from the heated fluids; and

controlling the temperature and the flow rate of the fluids into the patient so that the core temperature of the patient does not exceed predetermined levels, and so that the temperature increase caused by mixed heated fluids and blood does not injure the patient.