Burn patient resuscitation system and method

• US 7,857,803 B1
• Filed: 03/19/2008
• Issued: 12/28/2010
• Est. Priority Date: 03/19/2007
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System), United States Army (U.S. Department Of Defense)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Kramer, George, Salinas, Jose, Drew, Guy A.
• Primary Examiner(s): Sirmons; Kevin C.
• Assistant Examiner(s): CARPENTER, WILLIAM R
• Application Number:
  US12/076,554
• Time in Patent Office: 1,014 Days
• Field of Search: 604/31, 604/66, 604/131, 604/151, 604/503, 604/504
• US Class Current: 604/503
• CPC Class Codes: A61B 5/20 for measuring urological functions restricted to the evaluation of the urinary system A61B5/4375 takes precedence
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61M 2202/0496 Urine
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: G16H 10/60 for patient-specific data, e.g. for electronic patient records
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A method and system for operating a semi-closed loop and/or a closed loop resuscitation of a burn patient in view of patient information and other physiological data gathered as part of the method and/or by the system. The method in at least one embodiment includes receiving patient information, calculating an infusion rate based at least on part on a portion of the received patient information, outputting the infusion rate to an infusion pump, obtaining a urinary output, calculating a new infusion rate using infusion rate model based constants, and outputting the new infusion rate to an infusion pump. In some embodiments, the method includes notifying medical staff when problems arise, displaying information regarding the resuscitation, and setting limits regarding the infusion rates.

Claims

1. A method for controlling the operation of a resuscitation system used to resuscitate a burn patient, the method comprising:

receiving patient data including percentage of total body surface area;

calculating an initial infusion rate based on at least the patient data;

outputting the initial infusion rate to an infusion pump;

obtaining a current urinary output from a sensor monitoring urinary output;

calculating a new infusion rate based on at least the current infusion rate, the current urinary output, an infusion rate constant, and a urinary constant where at least the infusion rate constant is determined based on time post burn, where the new infusion rate is calculated using the following equation

2. The method according to claim 1, further comprising:

repeating obtaining the current urinary output, calculating the new infusion rate, and outputting the infusion rate until receiving a notification to terminate the resuscitation.

3. The method according to claim 2, further comprising filtering the urine output over a period of time longer than the frequency between calculating the new infusion rate.

4. The method according to claim 1, further comprising after calculating a new infusion rate:

displaying the calculated new infusion rate,

receiving acceptance of the new infusion rate or a replacement infusion rate from a user,

when a replacement infusion rate is received, sending the replacement infusion rate to the infusion pump in place of the new infusion rate.

5. The method according to claim 1, further receiving flow rate data from the infusion pump prior to calculating the new infusion rate.

6. The method according to claim 1, wherein the received urinary output is in units of volume, the method further comprising

converting the urinary output from units of volume to units for flow rate prior to calculation of the new infusion rate.

7. The method according to claim 1, further comprising:

analyzing the urinary output for at least one problem;

notifying medical staff when at least one problem exists; and

after notifying, receiving instructions to continue or terminate the method.

8. The method according to claim 7, further comprising continuing with the method when no instruction is received and a predetermined time has elapsed since the notification.

9. The method according to claim 1, further comprising displaying data regarding at least one of infusion rate and urine output.

10. The method according to claim 1, wherein the target urinary output is towards the end of a target urinary output range furthest from the current urinary output.

11. The method according to claim 1, wherein the infusion rate constant decreases in at least three phases as time since burn increases.

12. A method for controlling the operation of a resuscitation system used to resuscitate a burn patient, the method comprising:

receiving patient data including percentage of total body surface area;

calculating an initial infusion rate based on at least the patient data;

outputting the initial infusion rate to an infusion pump;

obtaining a current urinary output from a sensor monitoring urinary output;

calculating a new infusion rate based on at least the current infusion rate, the current urinary output, an infusion rate constant, and a urinary constant where at least the infusion rate constant is determined based on time post burn, the new infusion rate is calculated using the following equation

13. A method for controlling the operation of a resuscitation system used to resuscitate a burn patient, the method comprising:

receiving patient data including percentage of total body surface area;

calculating an initial infusion rate based on at least the patient data;

outputting the initial infusion rate to an infusion pump;

obtaining a current urinary output from a sensor monitoring urinary output;

calculating an urinary output error based on a difference between a target urinary output the current urinary output;

calculating a new infusion rate based on at least the current infusion rate added to the urinary output error multiplied by a ratio of an infusion rate constant and a urinary constant;

outputting the new infusion rate to the infusion pump; and

repeating obtaining the current urinary output, calculating the urinary output error, calculating the new infusion rate, and outputting the infusion rate a plurality of times.

14. The method according to claim 13, further comprising

comparing the new infusion rate to a minimum infusion rate;

and

when the new infusion rate is less than the minimum infusion rate, setting the new infusion rate to the minimum infusion rate prior to outputting the new infusion rate to the infusion pump.

15. The method according to claim 13, wherein the new infusion rate is calculated using the following equation

16. The method according to claim 15, wherein the urinary output error is further multiplied by at least one of a modifier based on the patient'"'"'s weight, a modifier based on the percentage of the total body surface area, and a Gaussian function calculated using the target urinary output.

17. The method according to claim 15, wherein the infusion rate constant varies base on hours post burn.

18. A method for controlling the operation of a resuscitation system used to resuscitate a burn patient, the method comprising:

receiving patient data including percentage of total body surface area and time since the patient was burned;

calculating an initial infusion rate based on at least the patient data;

outputting the initial infusion rate to an infusion pump;

obtaining a current urinary output from a sensor monitoring urinary output;

calculating an urinary output error based on a difference between a target urinary output and the current urinary output;

calculating a new infusion rate based on at least the calculated urinary output error multiplied by a constant calculated in part based on an exponential function with the input of hours post burn for the patient with the result being added to the current infusion rate;

outputting the new infusion rate to the infusion pump; and

repeating obtaining the current urinary output, calculating the urinary output error, calculating the new infusion rate, and outputting the infusion rate a plurality of times.

19. The method according to claim 18, wherein the constant is calculated from a ratio of an infusion rate constant having the exponential function and a urinary constant that is independent of time since burn.