MX2008005053A - Techniques for evaluating urinary stress incontinence - Google Patents

Abstract

Techniques for detecting stress urinary incontinence use a pressure sensing catheter the electrical indications of which are applied to a processing unit for detecting pressure levels generated during involuntary coughs. The involuntary coughs are induced preferentially by using a nebulized composition of L-tartrate in a pharmaceutically acceptable carrier. The area under the curve generated from pressure samples is calculated and used in conjunction with the detection of urine leakage to determine the existence of stress urinary incontinence.

Description

TECHNIQUES FOR EVALUATING URINARY INCONTINENCE Cross Reference with Related Requests This application incorporates as a reference in its entirety and claims the priority of the North American Provisional Application Series No. 60 / 727,740, filed on October 18, 2005, titled Method for Diagnosing Urinary Incontinence Through Involuntary Cough, of the inventors W. Robert Addington, Stuart Miller and Robert Stephens, and claims the priority and incorporates as reference the North American Provisional Application Series No. 60 / 752,351, filed on December 21, 2005, entitled Foley Catheter that Has Inventors Pressure Transducer W. Robert and Mary Briganti. This application is related to the US Patent Application Serial No. 10 / 783,442, filed on February 20, 2004, entitled Apparatus for Evaluating the Reflex of a Patient's Laryngeal Cough and Associated Methods, from the inventors W. Robert Addington, Stuart Miller and Robert Stephens, which is incorporated in its entirety to the present invention as a reference. Field of the Invention The present invention is directed to the field of medical devices and tests, and more particularly, to devices and techniques for evaluating stress urinary incontinence.

Background of the Invention According to the American Academy of Family Physicians, urinary incontinence (Ul) affects approximately two million people in the United States alone. Although urinary incontinence can occur in both men and women, it is more common in women around the age of 50. There may be Ul causes, which include age-related atrophic changes in the genitourinary anatomy in women after menopause, enlargement of the prostate in men, as well as generalized weakening of the pelvic floor muscles, medication side effects, immobility, urinary tract infection and several underlying medical co-morbidities, including diabetes and hypercalcemia. There are four basic types of urinary incontinence; functional, over-flow, impulse and tension. Stress urinary incontinence occurs when there is sudden pressure on the lower abdominal muscles, such as coughing, blowing the nose, laughing or lifting. Stress urinary incontinence is often secondary in part to the weakening of the pelvic floor musculature, and is common after deliveries or abdominal surgeries. It has been estimated that stress urinary incontinence occurs at least once a week in one third of adult women. (1) Additional reports indicate that more than 65% of female patients with incontinence in the United States or 8.3 million women experience stress urinary incontinence. Of these women, approximately 85% or 7 million have incontinence mainly due to hyper-mobility of the bladder outlet, and approximately 15% or 1.3 million have incontinence mainly due to an intrinsic sphincter deficiency. Regardless of the etiology of Ul, for the affected person it can be a source of significant discomfort and social isolation. As a result of this social stigma, many patients are reluctant to address this aspect with their doctor. Most physicians "classify" urinary incontinence by verbal or written questionnaires by the patient only. The additional basic evaluation may include a stress test for voluntary coughing, daily emptying, residual urine volume after emptying and urinalysis. (2) A patient who experiences urinary incontinence should be diagnosed appropriately to identify the specific type of incontinence of which he suffers. The treatments may be different, depending on the type of incontinence. Therefore, an adequate diagnosis becomes very important at least for this reason. Stress urinary incontinence can result mainly in adult women due to the loss of extrinsic support of the pelvic organs and the bladder neck. The tissues of the pelvis and the distal urethra contain estrogen and progesterone receptors. After menopause and the decrease of hormones, the tissues of the urethra can lose elasticity and become somewhat flaccid. Under these conditions, any increase in intra-abdominal pressure causes urine in the bladder to be pushed outward as a resistance that overcomes the urethra, resulting in the affectation of urine. This condition is known as stress urinary incontinence and occurs in the absence of contractions by the detrusor muscle of the bladder. Stress urinary incontinence may respond to treatment with exogenous estrogens, although this is not an effective treatment for all patients, particularly depending on age. Alternative treatments may include pelvic muscle exercises, a-adrenergic agents, such as phenylpropanolamine, which act on a-adrenergic receptors along the urethra and increase urethral tone. The most common cause of urinary incontinence, however, is detrusor hyperreflexia, or detrusor muscle hyperactivity. This type of incontinence is considered to result from the lack of detrusor muscle inhibition due to a decreased detrusor reflex in the brainstem. However, most of the affected adults do not seem to have an underlying neurological defect. In this condition, the treatment may include antispasmodic agents that tend to relax the bladder wall. A typical test used to distinguish these two types of urinary incontinence is one that increases the intra-abdominal pressure so that, in turn, places pressure on the bladder. The Valsalva maneuver is one of those tests. In this technique, the patient generates a muscular contraction of the chest, abdomen and diaphragm in a forced exhalation against a closed glottis. This increases pressure within the thoracic cavity and also in the abdominal cavity. The Valsalva maneuver also refers to the elevation of pressure in the nasopharynx through a forced exhalation with the mouth closed and the nostrils punctured. For example, to clear the patency of Eustachian tubes. Other testing techniques involve having a patient change up and down to shake the bladder, or bend forward to compress the abdomen. Still another method implies that the patient has to generate one or more strong voluntary coughs.

However, it is desirable that some patients do not have the ability to carry out these physical actions. For example, a patient may not have the ability to jump, or flex, to generate a strong voluntary cough. In addition, there are some patients who do not need to be diagnosed correctly based on the cough test, possibly because their cough is not strong enough. Therefore, there is a need for alternative or supplementary tests to help diagnose stress urinary incontinence. A more complete description of the methods to evaluate urinary incontinence is found in the February 2006 article by JL Martin and associates, entitled "Systematic review and evaluation of methods to evaluate urinary incontinence (hereinafter referred to as the Systematic review"). ). Prior Art Problems One of the problems associated with the above techniques is that some patients do not have the capacity or do not want to perform the physical actions to the extent necessary. For example, a patient may not have the ability to jump or flex, or to generate a strong voluntary cough. Some patients may have the ability to perform these actions, but may not want to perform them because the involuntary release of urine may be uncomfortable or contrary to what they consider appropriate in society. Brief Description of the Invention Several aspects of the present invention are directed towards devices and techniques for evaluating stress urinary incontinence. Particularly, the present invention is directed towards the evaluation of urinary stress incontinence using a reflexive cough test (RCT), which triggers involuntary cough in the patient. Said involuntary cough overcomes some of the problems of the prior art and produces a more reliable test for stress urinary incontinence. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in more detail with reference to the following drawings. Figure 1 shows a flowchart of a technique for evaluating a patient with respect to stress urinary incontinence according to an aspect of the present invention. Figure 2 shows a flow diagram of a technique to carry out a reflexive cough test (RCT). Figure 3 shows a catheter that can be used to carry out various aspects of the present invention. Figure 4 is an illustration of a portable processing apparatus that can be used to carry out the present invention. Figure 5 is a block diagram of an exemplary processing apparatus that can be used to carry out aspects of the present invention. Figure 6 is a flowchart of software that is used to program a processing apparatus according to an aspect of the present invention. Figure 7A and 7B illustrate test results of voluntary cough comparison techniques and involuntary cough to assess urinary stress incontinence. Detailed Description of the Invention Figure 1 shows a flow diagram of a technique for evaluating a patient with respect to stress urinary incontinence according to an aspect of the present invention. As an initial step, a pressure stop catheter is inserted into the empty bladder of a patient (100). The patient's bladder is slowly filled with sterile water until 200 ml (110) has been delivered. The patient is then asked to cough voluntarily (120) and the results of the voluntary cough are recorded (130) recording the variations in pressure as a function of time recording whether the cough induced or not involuntary expulsion of urine. See number 130. Subsequently, a reflex cough test (140) is performed and the results are recorded in a manner substantially similar to step 130. The details of the cough reflex tests are described as a whole in figure 2 Figure 2, shows a flow chart of a technique to perform a reflex cough test. With the trial fit, instead of asking the patient to cough voluntarily, the patient is given a nebulized composition of L-tartrate in a pharmaceutically vehicle, as described in numbers 100 and 110 of figure 1. acceptable (200). Variations in bladder pressure that occur during the involuntary cough included in step 200 are subsequently recorded and plotted for deployment (210). The patient is checked for any urinary leakage that occurs during involuntary cough (220). Figure 3 shows a catheter that can be used to carry out various aspects of the present invention. The catheter 300 includes a pressure sensor 310 and leads or conductive paths that conduct the electrical output of the pressure sensor 310 to an external circuit 320. The leads or paths hereinafter are referred to as pressure sensor leads 320. The lumen The catheter can be used to fill or drain the patient's bladder, as appropriate. Examples of a catheter that can be used in accordance with the present invention may include a Foley catheter equipped with a pressure sensor. Figure 4 is an illustration of a portable processing apparatus that can be used to carry out the present invention. As shown on the device's display screen, the variation in pressure that occurs as a function of time during voluntary or involuntary coughing is shown. Figure 5 is a block diagram of an exemplary processing apparatus that can be used to carry out aspects of the present invention. Figure 5 is a block diagram illustrating a computation system 500, in which one embodiment of the present invention can be implemented. The computer system 500 includes a bus 502 or other communication mechanism for communicating information, and a processor 504 coupled with the bus 502 for processing information. The computer system 500 also includes a main memory 506, such as a random access memory (RAM), or other dynamic storage device, coupled to the bus 502 to store information and instructions to be executed by the 504 processor. The main memory 506 can also be used to store temporary variables or other intermediate information during execution and instructions to be executed by the processor 504. The computer system 500 also includes a read-only memory (ROM) 508 or other static storage device coupled to the bus 502, for storing static information and instructions for processor 504. Storage apparatus 510, such as a magnetic disk or optical disk, is provided and coupled to bus 502 for storing information and instructions. The computation system 500 can be coupled via bus 502 to display 512, such as a cathode ray tube (CRT), to display information to the user of a computer. An input device 514, including alphanumeric or other keys, is coupled to the bus 502 to communicate information and command selections to the processor 504. Another type of user input device is the cursor control 516, such as a mouse, a ball tracking, or cursor direction keys to communicate address information and command selections for the processor 104 and to control the movement of the cursor on the screen 512. This input device normally has two degrees of freedom on two axes, a first axis ( for example, x) and a second axis (for example, y), which allows the device to specify the positions in a plane. The computation system 500 operates in response to the processor 504 executing one or more sequences of one or more instructions contained in the main memory 506. Said instructions can be read in the main memory 506 from another computer readable medium., such as the storage apparatus 510. Execution of the instruction sequences contained in the main memory 506 causes the processor 504 to perform the process steps described herein. In alternative embodiments, the cable circuit may be used in place of, or in combination with, software instructions to implement the present invention. Therefore, the embodiments of the present invention are not limited to any specific combination of hardware and software circuits. The term "computer readable medium" as used in the present invention, refers to any means that participates in providing instructions to processor 504, for execution. Said means can take many forms, including but not limited to, non-volatile media, volatile media and means of transmission. The non-volatile medium includes, for example, optical or magnetic disks, such as storage apparatus 510. The volatile means includes dynamic memory, such as main memory 506. The transmission means include coaxial cables, copper cables and optical fibers, including cables comprising the bus 502. The transmission means can also take the form of acoustic or light waves, such as those generated during radio and infrared wave data communications. Common forms of readable computer media include, for example, a floppy disk, a floppy disk, a hard disk, a magnetic tape or any other magnetic media, a CD-ROM or any other optical media, punch cards, tape paper, and other physical media with hole patterns, a RAM, a PROM, and an EPROM, a FLASH-EPROM, or any other memory chip or cartridge, a conveyor wave as described below, or any other means of which can be read on a computer. Various forms of the computer readable medium may be involved in carrying out one or more sequences of one or more instructions for the execution of the processor 504. For example, the instructions may be initially carried on a magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions via telephone line using a modem. A local modem of the computer system 500 can receive the data on the telephone line and use an infrared transmitter to convert the data to an infrared signal. An infrared detector can receive the data carried in the infrared signal and the appropriate circuit can put the data in the bus 502. The bus 502 carries the data to the main memory 506, from which the processor 504 retrieves and executes the instructions. The instructions received by the main memory 506 can optionally be stored in the storage device 510, either before or after execution by the processor 504. Figure 6 is a flowchart of a software used to program an apparatus processing according to one aspect of the present invention. The processing apparatus is programmed to produce sample pressure in a repetitive manner of the sensor (600). Upon receipt of a start or start signal, the processor can start to record pressure sensor data (610). The start signal can be generated using either a rapid increase in pressure, detecting that a pressure threshold value is being exceeded, or receiving an activation signal initiated by a user. Said signal was described together with the US Patent Application Serial No. 10 / 783,442, filed on February 20, 2004, entitled Apparatus for Evaluating Reflex of Cough of a Patient's Larynx and Associated Methods, from the inventors W. Robert Addington, Stuart Miller and Robert Stephens, referred to above. After the reception of the start signals, the processing memory stores the samples and displays the trace of the pressure sample values (620). At the end of the cough sequence, the software is programmed to calculate the area under the curve of a trace of the sample values (630). The values of the areas under the curve (AUC) are calculated through the numerical intravesical pressure integration over time either with the Simpson 3/8 rule or Bode's rule (or Boole's). Both the Simpson 3/8 rule and Bode's rule (or Boole's) are numerical integration methods that produce more accurate results for AUC than the trapezoidal method. Simpson's Rule 3/8 l f. { x) dx K. { /? + / a + 3 (/ l + / 4 + ... + / "- 2) + 3 (/ 2 + + - + /« - + 2 (/ 3 + «+ ... + fn-z ).}. fi-1 +3? / < a +?) + 2? t = 2, β, 8 > - = 3¿, e, ~ J Bode's Rule (Boole's) f) dx = i h (7! + 32/2 + 12/3 +32/4 +7/5) - ¿A7 / «(£).

All AUC values were calculated using the Bode's rule, except for patient No. 1, which was calculated with Simpson's 3/8 rule. The Bode method (Boole's) was not very adept at handling some data points (3). The process can selectively display the area under the curve calculated for the user either with, or separated from, the display of the trace of the sample values (640). Optionally, the raw data may be produced and calculated to be used outside the processing apparatus (650). This can be done using interface 518. FIGS. 7A and 7B illustrate test results comparing techniques of voluntary coughing and involuntary coughing to assess urinary stress incontinence. The tests that produced the results shown in Figure 7A and 7B are described as indicated below. Objective The objective of this study was: 1. To evaluate the effectiveness of the cough reflex test (RCT) versus voluntary cough, to confirm stress urinary incontinence in female subjects with a history of mild urinary incontinence as determined through Incontinence. Quality of Life Instrument (l-QOL); and 2. Correlate, if indicated, intravesicular pressure measurements with urinary filtration after RCT. Materials and Methods We carried out voluntary and involuntary coughing (RCT) provocation maneuvers during urodynamic tests in 6 women. Four women had a history of mild urinary incontinence and two were normal controls. The order of cough provocation procedures was randomized. Before the urodynamic evaluation, the subjects were asked to empty the bladder (confirmed by ultrasound). Using the sterile technique, calibrated bladder and rectum catheters were placed and a continuous dual channel pressure recording was carried out and the subject's bladder was slowly filled with sterile water until 200 mL was delivered. The Cough Filtration Point Pressure (CLPP) was evaluated with a bladder volume of 200 mL. Filtration was determined by visual inspection of the perineum by the Investigator during the cough, and was marked electronically in the impression. If the subject did not have a leak with a cough maneuver in the semi-recumbent position, the standing position was used. The urodynamic tests were completed filling up the entire capacity to observe detrusor instability. After the instruction, the subjects carried out a voluntary cough with maximum force (VC) and an involuntary cough. The involuntary cough was provoked by stimulating the cough reflex of the larynx and carrying out the RCT with the patient's nose keeping closed. The RCT involves inhaling a 20% concentration of L- (+) - tartaric acid dissolved in normal saline solution (Nephron Pharmaceuticals, Orlando, FL) supplied by a jet nebulizer. An independent reviewer used the continuous pressure record of each subject to determine peak pressures, measure the duration of cough events, count the number of pressure settings, and derive the area numbers under the curve (AUC). Results Peak pressures were similar when comparing voluntary cough with RCT (Figures 7A and 7B). The duration of cough events, AUC, and the number of adjustments all increased with RCT relative to voluntary cough. None of the 2 normal subjects filtered with any of the cough maneuvers. Of the 4 subjects with urinary incontinence due to mild tension (diagnosed by l-QOL), 3 leaked with RCT and 2 leaked with VC. We identified a possible transport effect when evaluating subjects who were randomized to undergo RCT tests before VC. There seems to be a relative increase in AUC, peak pressure, duration and in the adjustment number with the VC tests, when the voluntary cough test was carried out after, instead of before, the RCT (figures 7A and 7B). It is notable that both of the subjects who filtered with voluntary cough were randomized to have the RCT test first. Conclusion RCT provides considerable "tension" in subjects with stress urinary incontinence and seems to be an involuntary maneuver useful to cause leakage in subjects with this condition. No other involuntary maneuver has been studied in evaluating this condition. The data suggest that RCT may be more efficient in causing leakage in subjects with urinary stress incontinence than voluntary cough. The present invention has been described above, in which the description of the preferred embodiments of the present invention is described. Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those commonly understood by one skilled in the art of which the present invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or development of tests of the present invention, suitable methods and materials are described. In addition, the materials, methods and examples provided are illustrative only of nature and are not intended to be limiting. Accordingly, the present invention can be represented in many different forms and should not be construed as limited to the embodiments illustrated herein. Rather, these illustrated embodiments are provided solely for purposes of example so that this description will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Other features and advantages of the present invention will be apparent from the detailed description, and from the appended claims.

Claims (11)

1. CLAIMS 1. A method to detect stress urinary incontinence, comprising the steps of: a. inserting a pressure detection catheter into the empty bladder of a patient; b. eliminate the patient's bladder to a predetermined level; c. induce one or more involuntary coughs in the patient; and d. record the pressure levels detected by the pressure detection catheter during involuntary coughing; and e. determine stress urinary incontinence, identifying urine leakage accompanied by peak pressures above a certain level, where: the step of recording the pressure levels detected by the pressure detection catheter comprises the steps of: repeated the pressure levels detected by the pressure detection catheter, and 2. record the pressure levels sampled, and 3. plot the pressure levels sampled, and 4. display the resulting trace to a user, and f. calculate the area under the curve that results from the trace of the pressure levels sampled. The method as described in claim 1, characterized in that it also comprises the step of displaying the value of the area under the curve. 3. The method as described in claim 1, characterized in that it comprises using the Simpson formula to calculate the area under the curve. 4. The method as described in the claim 1, characterized in that it comprises using the Bode formula to calculate the area under the curve. The method as described in claim 1, characterized by the step of inducing one or more involuntary coughs in the patient comprising administering a nebulized composition of L-tartrate in a pharmaceutically acceptable carrier. The method as described in claim 1, characterized in that the step of recording the pressure levels detected by the pressure detection catheter during the involuntary cough is initiated by: a. a rapid increase in pressure; b. a signal initiated by a user; or c. a signal initiated by activation of a nebulizer. 7. The method as described in the claim 1, characterized in that the step of filling the bladder of the patient is followed by the patient having to produce a voluntary cough before or after the step of inducing one or more involuntary coughs. The method as described in claim 1, characterized in that in the step that the patient has to produce voluntary cough, it occurs insofar as it registers in the pressure levels detected by the pressure detection catheter during the cough. voluntary 9. An apparatus for detecting stress urinary incontinence, comprising: a. a pressure detection catheter; and b. a processor for receiving electrical signals from the pressure sensing catheter wherein the processor is configured to repeatedly display electrical signals in which the processor is configured to deploy a sample passage of the electrical signals, and wherein the processor is configured to calculate the area under the curve that results from the trace of the samples of the electrical signals received during the involuntary cough. 10. The apparatus as described in claim 9, characterized in that it comprises using the Simpson formula or the Bode formula to calculate the area under the curve. 11. The apparatus as described in the claim 9, characterized in that the processor is included in a portable device.