Dosage control for drug delivery system

• US 20060009734A1
• Filed: 07/07/2004
• Published: 01/12/2006
• Est. Priority Date: 07/07/2004
• Status: Abandoned Application

• Current Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Martin, James F.
• Application Number:
  US10/886,255
• Publication Number:
  US 20060009734A1
• Time in Patent Office: Days
• US Class Current: 604/66
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• 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 20/17 delivered via infusion or injection

Abstract

A method for delivering intravenous drugs to a patient comprising programming a drug delivery system, including a controller and an infusion pump, with a maintenance rate or a loading dose for a drug and causing the drug delivery system to (a) calculate a loading dose based on the maintenance rate or a maintenance rate based on the loading dose, (b) administer the loading dose of the drug to the patient to rapidly achieve a desired level of effect, and (c) administer the drug at a first maintenance rate to maintain the level of effect.

Claims

1. A method for delivering intravenous drugs to a patient comprising:

programming a drug delivery system including a controller and an infusion pump with a maintenance rate or a loading dose for a drug;

causing the drug delivery system to;

(a) calculate a loading dose based on the maintenance rate or a maintenance rate based on the loading dose;

(b) administer the loading dose of the drug to the patient to rapidly achieve a desired level of effect; and

(c) administer the drug at a first maintenance rate to maintain the level of effect.

2. The method of claim 1 wherein the step of calculating a loading dose based on the maintenance rate or a maintenance rate based on the loading dose is based on a formula that correlates the maintenance rate and the loading dose recommended by the drug supplier.

3. The method of claim 2 wherein the formula is based upon a linear interpolation of the maximum loading dose and the maximum maintenance rate recommend by the drug supplier.

4. The method of claim 3 wherein the drug is propofol and the formula is:

LD=0.5*W*(MR/75)

where, LD=Loading Dose (mg), MR=Maintenance Rate (μ

g/kg/min), W=Weight (kg) of the patient.

5. The method of claim 1 wherein the step of administering the loading dose is performed using an infusion pump at an infusion rate approximately equal to the maximum infusion rate of the pump.

6. The method of claim 1 wherein the step of administering the loading dose is conducted by administering the loading dose over a predetermined period.

7. The method of claim 1 wherein the drug delivery systems tracks the cumulative loading dose administered to the patient, wherein the cumulative loading dose is calculated based on the formula:

LD_—

cum_x=LD_—

cum<sub>x−

1</sub>+amount of LD currently delivered in sample x

8. The method of claim 1 wherein the method includes the additional steps of:

programming the drug delivery system with a second maintenance rate whereupon the system;

(a) calculates an incremental loading dose for the drug based on the second maintenance rate

(b) administers the incremental loading dose to the patient to rapidly achieve the new desired level of effect; and

(c) administers the drug at the second maintenance rate to maintain the new level of effect.

9. The method of claim 8 wherein the incremental loading dose is calculated for the second maintenance rate and the cumulative loading dose based on a formula that correlates the maintenance rate and the loading dose recommended by the drug supplier

10. The method of claim 9 wherein the drug is propofol and the incremental loading dose is calculated from the second maintenance rate and the cumulative loading dose based on the formula:

Incremental LD=0.5*W*(MR_new/75)−

LD_—

cum

11. The method of claim 9 wherein the second maintenance rate is increased from the first maintenance rate.

12. The method of claim 11 wherein the drug is administered to the patient using an infusion pump and the incremental loading dose is administered at a rate approximately equal to the maximum infusion rate of the pump.

13. The method of claim 11 wherein the step of administering the incremental loading dose is conducted by administering the incremental loading dose over a predetermined period.

14. The method of claim 9 wherein the second maintenance rate is less than the first maintenance rate.

15. The method of claim 14 wherein the incremental loading dose is a negative loading dose.

16. The method of claim 15 wherein the negative loading dose is administered by setting a infusion rate to zero for a period of time.

17. The method of claim 16 wherein the zero period of time is calculated based on the incremental loading dose.

18. The method of claim 17 wherein the zero time period is calculated using the formula:

Zero_time=60*1000*LD/(MR*W)

19. The method of claim 1 wherein the method further includes the step of administering a transient bolus of the drug to temporarily increase in the patient'"'"'s level of effect.

20. The method of claim 1 wherein the steps of administering are discontinued if adverse physiology is detected

21. The method of claim 1 wherein the step of administering is discontinued if adverse physiology is detected during a maintenance rate infusion.

22. The method of claim 1 wherein the step of administering is discontinued if adverse physiology is detected during a loading dose infusion.

23. The method of claim 1 wherein the method includes reducing the maintenance rate if adverse physiology or an adverse trend in physiology is detected.

24. The method of claim 23 wherein the maintenance rate is reduced if adverse physiology or an adverse trend in physiology is detected during a maintenance rate infusion.

25. The method of claim 23 wherein the maintenance rate is reduced if adverse physiology or an adverse trend in physiology is detected during a loading dose infusion.

26. The method of claim 23 wherein the step of reducing the maintenance rate includes stopping administering the drug and determining the maintenance rate reduction by calculating an apparent maintenance rate at the time the adverse physiology or trend has cleared based on the cumulative loading dose.

27. The method of claim 26 wherein the drug is propofol and the maintenance rate reduction is determined by calculating the apparent maintenance rate at the time the adverse physiology or trend has cleared (physiology returns to normal), based on the formula:

MR_apparent=75*LD_—

cum/(0.5*W)

28. The method of claim 8 wherein the method includes the further step of monitoring the patient'"'"'s level of effect

29. The method of claim 28 wherein the level of effect is the level of sedation

30. The method of claim 29 wherein the patient'"'"'s level of sedation is based on the patient'"'"'s response to an automated response monitoring system (ARM).

31. The method of claim 28 wherein the step of programming of a second maintenance rate is limited based upon the patient'"'"'s level of effect.

32. The method of claim 31 wherein the programming of the second maintenance rate is limited based upon the patient'"'"'s response to ARM.

33. The method of claim 28 wherein the maintenance rate is automatically reduced based on the monitored level of effect.

34. The method of claim 33 wherein the maintenance rate is automatically reduced based on the patient'"'"'s level of sedation.

35. The method of claim 34 wherein the maintenance rate is automatically reduced if the patient is not responsive to ARM for a predetermined time.

36. The method of claim 35 where the maintenance rate is reduced by 5% if the patient is not responsive to ARM for 15 minutes.

37. The method of claim 8 wherein the method includes the step of monitoring the patient'"'"'s level of effect based on a patient tuned system that gives the patient input to the drug delivery.

38. The method of claim 37 wherein the patient tuned system sends a request to the patient to generate a response, wherein the request is a query regarding patient'"'"'s comfort level.

39. The method of claim 38 wherein the patient'"'"'s level of sedation is monitored based on the patient'"'"'s response to the request.

40. The method of claim 39 wherein the patient'"'"'s response to the request is used to increase the maintenance rate.

41. The method of claim 40 wherein the time it takes for the patient to respond to the request is used calculate the amount the maintenance rate will be increased.

42. The method of claim 39 wherein the maintenance rate will be gradually decreased if the patient has not responded to the request for a specified period of time.

43. A method for sedating a patient comprising:

(a) selecting a first maintenance rate or an initial loading dose for a sedation drug;

(b) calculating an initial loading dose based on the maintenance rate or a maintenance rate based on the initial loading dose;

(c) administering the initial loading dose of the sedation drug to the patient to achieve a desired level of sedation;

(d) administering the sedation drug at a first maintenance rate to maintain the level of sedation;

(e) selecting a second maintenance rate to adjust the level of sedation;

(f) calculating an incremental loading dose based on a cumulative loading dose and the second maintenance rate;

(g) calculating the cumulative loading dose administered to the patient based on the formula;

LD_—

cum_x+1=LD_—

cum_x+amount of LD delivered in sample;

(h) administering the incremental loading dose to the patient to achieve a second level of sedation; and

(i) administering the sedation drug at the second maintenance rate to maintain a second level of sedation.

44. The method of claim 43 wherein the step of administering the loading dose is performed using an infusion pump at an infusion rate approximately equal to the maximum infusion rate of the pump.

45. The method of claim 43 wherein the step of administering the loading dose is conducted by administering the loading dose over a predetermined period.

46. The method of claim 43 wherein the second maintenance rate is greater than the first maintenance rate.

47. The method of claim 43 wherein the method includes the step of monitoring the patient'"'"'s level of sedation based on patient'"'"'s response to an automated responsiveness monitoring system (ARM).

48. The method of claim 47 wherein the step of monitoring the level of sedation includes sending a request using the automated responsiveness monitoring system (ARM) to the patient to generate a response, wherein the request is a query regarding the patient'"'"'s comfort level.

49. A drug delivery system that delivers a loading dose and a maintenance rate of a drug to a patient, the system including an infusion pump and a controller, the controller being programmed such that the system performs the steps of:

(a) calculating a loading dose based on the maintenance rate or a maintenance rate based on the loading dose;

(b) administering the loading dose to the patient to achieve a desired level of effect; and

(c) administering the drug at a first maintenance rate to maintain the level of sedation.

50. The drug delivery system of claim 49 wherein the step of calculating a loading dose based on the maintenance rate or a maintenance rate based on the loading dose is based on a formula that correlates the maintenance rate and the loading dose recommended by the drug supplier.

51. The drug delivery system of claim 50 wherein the formula is based upon a linear interpolation of the maximum recommended loading dose and the maximum recommended maintenance rate.

52. The drug delivery system of claim 49 wherein the controller includes a setting to administer the loading dose by operating the infusion pump at an infusion rate approximately equal to the maximum infusion rate of the pump.

53. The drug delivery system of claim 49 wherein the controller includes a setting to administer the loading dose by administering the loading dose over a predetermined period.

54. The drug delivery system of claim 49 wherein the drug delivery system tracks the cumulative loading dose administered to the patient, wherein the cumulative loading dose is calculated based on the formula:

LD_—

cum_x=LD_—

cum<sub>x−

1</sub>+amount of LD currently delivered in sample x

55. The drug delivery system of claim 49 wherein the controller is programmed with a second maintenance rate whereupon the system:

(a) calculates an incremental loading dose for the drug based on the second maintenance rate

(b) administers the incremental loading dose to the patient to rapidly achieve the new desired level of effect; and

(c) administers the drug at the second maintenance rate to maintain the new level of effect.

56. The drug delivery system of claim 51 wherein the controller is programmed to calculate the loading dose based on the formula:

LD=0.5*W*(MR/75)

where, LD=Loading Dose (mg), MR=Maintenance Rate (μ

g/kg/min), W=Weight (kg) of the patient.

57. The drug delivery system of claim 51 wherein the controller is programmed to calculate the incremental loading dose based on the formula:

Incremental LD=0.5*W*(MR_—

new/75)−

LD_—

cum

58. The drug delivery system of claim 55 wherein the controller is programmed to administer the incremental loading dose over a predetermined period.

59. The drug delivery system of claim 49 where the infusion pump delivers the drug at an infusion rate that can be set to zero for a period of time.

60. The drug delivery system of claim 59 wherein the controller is programmed to calculate the zero period of time based on the incremental loading dose.

61. The drug delivery system of claim 60 wherein the zero time period is calculated using the formula:

Zero_—

time=60*1000*LD/(MR*W)

62. The drug delivery system of claim 49 wherein the controller includes a setting to deliver a transient bolus of the drug to temporarily increase in the patient'"'"'s level of effect.

63. The drug delivery system of claim 49 wherein the system includes sensors for sensing the physiology of the patient and the controller is programmed to discontinue the step of administering the drug if adverse physiology or an adverse trend in physiology is detected.

64. The drug delivery system of claim 63 wherein the controller is programmed to calculate a maintenance rate reduction by calculating the apparent maintenance rate at the time the adverse physiology or trend has cleared (physiology returns to normal), based on the formula:

MR_—

apparent=75*LD_—

cum/(0.5*W)

65. The drug delivery system of claim 49 wherein the system further includes an automated response monitoring system (ARM).

66. The drug delivery system of claim 65 wherein the system further includes a patient response input.