EP2858692A1

EP2858692A1 - Device and method for monitoring a loss of blood fluid

Info

Publication number: EP2858692A1
Application number: EP13737307.2A
Authority: EP
Inventors: Régis Logier; Didier CARETTE; Jean-Pierre Sozanski
Original assignee: Centre Hospitalier Regional Universitaire de Lille CHRU
Current assignee: Centre Hospitalier Universitaire de Lille CHU
Priority date: 2012-06-12
Filing date: 2013-06-11
Publication date: 2015-04-15
Also published as: FR2991587B1; WO2013186447A1; FR2991587A1

Abstract

The present invention concerns a device for monitoring a loss of blood fluid of a patient and an associated monitoring method, said device comprising a central unit (2), at least one peripheral device (3) with means (4) for weighing and means (5) for storing said fluid, means (11) for transmitting a signal between the peripheral device (3) and the central unit (2) and, according to the invention, means (8) for inserting data relative to the patient and processing means (13) combining the data inserted relative to the patient and the data relative to the volume and flow rate of the losses of blood fluid, making it possible to determine at least one level of risk.

Description

Device. and method of monitoring a loss of blood fluid.

The present invention relates to a device and a method for monitoring the loss of a blood fluid.

The present invention will be particularly intended for monitoring the blood loss of a patient, in particular after a surgical operation.

BACKGROUND OF THE INVENTION After certain surgical operations, it is necessary to install a drain to facilitate the flow of blood. This drainage, performed at the level of the operative wound, in particular makes it possible to prevent the formation of hematomas and to promote the healing of tissues. Postoperative blood loss can have serious consequences, so it is necessary to monitor the volume of loss steadily in order to be able to intervene quickly, in case of excessive loss, either by performing a transfusion or by operating again. the patient.

In order to evaluate the blood loss of a patient, a first device is known consisting of recovering, in a flexible bag, the drained blood losses and regularly monitoring the evolution of the filling of the bag. This device, commonly used, has various disadvantages, on the one hand, it is imprecise as to the volume of loss and, on the other hand, it does not account for the loss rate which is a significant parameter of the evolution of the patient. Finally, it is a source of error because when the bag is at the end of filling and must be changed, the risk of forgetting to add the losses contained in the different pockets is increased.

A second known device is to use a pocket to recover blood loss and to continuously weigh this pocket. The advantage of this second The device is able to accurately measure the losses and also to take into account the changes of pockets, since it is in fact generally possible to add the volumes of the different pockets to the weighing means and to keep this information.

This second known device therefore reduces the risk of poor evaluation of the patient's blood loss. However, in the absence or spacing of visits by the person in charge of the surveillance, usually the nurse, there is a significant risk of discrepancy between the loss of blood and the detection of this loss. A third device is described in the document US 2007/0106177, it consists in an improvement of the second aforementioned device in that it provides, in addition, means for transmitting the weighing information towards a central processing unit . This device thus facilitates the task of the nurse who can in real time and remotely control the volume of loss of a patient. This third device, however, is not entirely satisfactory since the nurse has no information that can be used directly to determine the risk or urgency of a situation.

In fact, a blood loss of a given volume does not have the same consequences from one patient to another; it is easily understood, for example, that an adult according to his weight, his hematocrit or his hemoglobin level can not withstand the same blood loss as another.

Therefore, the third device described in document US 2007/0106177 does not alert the nurse of the real risk incurred by the patient. The nurse must therefore regularly consult on his monitor the losses of the patients for whom it is responsible and in addition determine, according to the volume of loss displayed, the level of risk, for each patient, and therefore the actions to be taken. Here again, the risk of error can not be ruled out, especially as the number and rotation of patients is important.

OBJECT OF THE INVENTION

The present invention aims to overcome the aforementioned drawbacks by providing a monitoring device wherein the information processing means allow differentiated information on the blood loss based on the physiological characteristics of the patient.

A second object of the present invention is to provide a monitoring device for generating in real time information on the level of risk reached by a patient.

A third object of the present invention is to provide a monitoring device for automatically generating an alarm as soon as a level of risk is reached by a patient, so that the controller is notified even without performing an active approach to monitoring.

A fourth object is to propose a method of implementing the monitoring device allowing a fast and reliable integration of the particular physiological characteristics of the patient.

SUMMARY OF THE INVENTION

For this purpose, the invention relates to a method for monitoring the loss of a body fluid of a patient comprising a central unit, at least one peripheral with weighing means and storage means of said fluid, and signal transmission means between the peripheral and the central unit. According to the invention, the device comprises means for introducing data relating to the patient and processing means combining the data entered relating to the patient and the data relating to losses of body fluid to determine at least one level of risk.

The invention also relates to a method for implementing the monitoring device.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood on reading a detailed exemplary embodiment with reference to the accompanying drawings, provided by way of non-limiting example, among which: FIG. 1 represents, in a schematic view, an exemplary embodiment of FIG. an installation comprising devices according to the invention,

FIG. 2 represents a flowchart of the various steps of the method relating to the invention.

DETAILED DESCRIPTION OF THE INVENTION Referring mainly to FIG. 1, there is shown a monitoring device 1 comprising a central unit 2 and a plurality of peripherals 3. In a simplified embodiment, it is possible to associate a single peripheral device 3 with a single device 3. CPU 2, however in practice to reduce costs, a network in star with several devices 3 connected to a single central unit 2 as shown in Figure 1 attached.

Each device 3 comprises weighing means 4 and storage means 5. The weighing means 4, known in itself, are advantageously made using a cantilever system equipped with a weight sensor 6 on These storage means 5 are preferably constituted by one or more pockets 7.

According to the advantageous embodiment described in the appended figures, the central unit 2 further comprises data input means 8 relating to the patient. Referring more particularly to FIG. 2, it can be seen that these patient data input means 8 comprise a keyboard 9 and a display 10.

Each device 3 further comprises transmission means 11 shared with the central unit 2. These transmission means 11 allow bidirectional transmission and are constituted by a radiofrequency transmission module preferably of "blue tooth" type.

In a degraded version of the device 1, it will however be possible to envisage a wired connection between the peripheral device 3 and the central unit 2.

In the preferred embodiment illustrated in the appended figures, the device 1 also comprises control terminals 12, these terminals 12 are mobile and allow the medical personnel to move around the premises and to connect both to the unit. Central 2 and the various peripherals 3. In the preferred embodiment these terminals 12 are computer tablets.

Advantageously, the terminals 12 comprise also means for inputting the data relating to the patient 8 so that the medical staff is not obliged to enter the data relating to the patient by means of the central unit 2, but can also perform the recording of the data with a patient. terminal 12 for example in the room where the patient is located.

In an alternative embodiment, data input means 8 are also provided at each device 3.

According to the invention, the device 1 further comprises means 13 for processing data from both the weighing means 4 and the patient information inserted via the data input means 8. Advantageously, these processing means 13 are integrated in the central unit 2. These processing means 13 comprise a memory 14, storing the blood loss data and the data relating to the patient. These processing means 13 further comprise a processing unit 15, advantageously constituted by a processor or a microcontroller to perform the calculations of the different thresholds defined below.

The monitoring device 1 also comprises at each device 3 securing means 16 for fixing the electronic module 17 of the device. These securing means 16 will advantageously be made by means of an adjustable clamp 18 whose dimensions are adapted to grip a bed bar. The non-electronic module 19, consisting essentially of the storage means 5, comprises cooperation means 20 with the electronic module 17, so that when the cooperation means are engaged, the module 19 acts on the load cell of the electronic module and the weighing can be performed.

Referring now mainly to Figure 2, there is shown a flow chart showing the various steps of implementation of the control device 1. The operation of the monitoring device 1 is preferably as described below. Firstly, the information relating to the patient is entered, for this purpose a nurse enters the data via the introduction means 8.

Different data can be introduced depending on the type of calculation performed by the processing unit. In fact conventionally, the maximum theoretical blood loss that a patient can undergo can be calculated according to several formulas, the treatment means 13 may in particular use the Bourke or Gross formula or a simplified formula described below. Thus, according to Bourke's formula, the maximum theoretical blood loss PST is given by the relation:

PST = VST * weight * ln (Hbpréop / Hbmin)

With:

- VST = the total blood volume in ml

- Hbpréop = preoperative hemoglobin concentration

- Hbmin = the minimum tolerated concentration of hemoglobin

According to Gross's formula, the theoretical maximum blood loss PST is given by the relation:

PST = VST * weight * 2 * (Hbpréop -Hbmin) / (Hbpréop + Hbmin)

According to the simplified formula, the maximum blood loss is given by the relation:

PST = 0.7 * weight * (Htepréop - Htemin) / (HTepréop)

With:

Htepeop = preoperative hematocrit

Htemin = the minimum tolerated hematocrit

The theoretical blood volume (VST) is calculated based on the weight, age, sex, and body mass index of the individual. The table shows below. an example of a table whose data is to be multiplied by the weight of the individual to obtain the VST in ml:

The value of Hbmin and Htemin is fixed according to the classification of the patient in coronary type or not. In the case of a patient having symptoms or coronary history, the Hbmin value is preferably equal to 10g / dl and the Htemin is 30g / dl. In the case of a patient identified as non-coronary, the Hbmin value is preferably equal to 8g / dl and the Htemin is 24g / dl.

Of course, the processing means 13 could also, in variants of use other formulas to calculate the maximum theoretical blood loss (PST) or even a specific figure if it has already been calculated for the patient.

The nurse enters all the data relating to the patient necessary for the calculation of the formulas used by the processing means 13. Possibly, other data useful in a medical or administrative context may also be introduced via the means for entering the data.

8.

Advantageously, the data entered will be name, surname, sex, PPI, weight, height, coronary type or not, type of formula required (Bourke, Gross, simplified), HTE preop HBeprope, date of birth, age. Advantageously the data used are those of the blood test of the patient performed just before the operation.

All these data introduced will make it possible to calculate the following data: BMI, critical Hb, critical HTE, preoperative loss, theoretical blood volume (VST) and finally theoretical maximum blood loss (PST). .

The processing means 13 thus calculate a threshold value SI called the first threshold value as a function of the data entered relating to the patient, this value Si corresponding to the maximum theoretical blood loss (PST). This first threshold value Si is subsequently compared with the data relating to the loss of body fluid measured by the weighing means. When this first threshold value SI is reached, an alert is generated and transmitted to the nurse.

In addition to the volume of blood loss, there is also the flow of this loss. Indeed, when the flow rate is too high, the risk of weakening the patient is high even if the volume of loss is not yet problematic. It is also understood that a sudden high loss rate accounts for a disruption in the patient's condition and, for example, haemorrhage, and therefore the patient must be examined in a very short time. For this purpose, a second threshold value S2 corresponding to a maximum loss rate is provided at the level of the monitoring device 1.

By way of example, this second threshold value S 2 will be of the order of 5 ml / kg / h. Beyond this limit, the processing means 13 will generate an alert by means of alarm 21. The flow measurements are preferably performed on a sliding window of one hour, however in embodiments and by example depending on the patient or the type of operation can also provide slippery windows shortened.

In the embodiment of the appended figures, the alert is an audible alert and for this purpose there is provided at the peripherals 3 integrated loudspeakers, not shown in the accompanying figures. Of course, other types of alerts, including bright could also be considered, possibly combined with the sound and arranged means, for example, in the guard room of the infirmary or in the patient's room.

Once the patient data entered by the nurse or other authorized person, the monitoring device 1 operates automatically. More precisely, the processing means 13 calculate the first and second threshold values S1 and S2 of maximum loss. Then transmission means 11 transfer the data measured by the weighing means 4 towards the processing means 13, advantageously in real time or, in an alternative embodiment, according to a control cycle with measurements spaced in time.

The treatment means 13 then compare the loss of body fluid measured by the weighing means 4 with the first threshold value Si.

Then the processing means 13 compare the loss rate measured by the weighing means 4 with the second value corresponding to a maximum loss rate.

When one of the threshold values SI or S2 is exceeded, the alarm means 21 generate an alarm signal. Advantageously, the monitoring device 1 makes it possible to generate at least one second alarm signal when one of the threshold values is exceeded by more than a given percentage K of said value.

By way of example, a second alarm signal is provided when the thresholds are exceeded by 5%, this alarm signal being an emergency signal.

In an alternative embodiment, it is also possible to provide various additional alerts when the loss levels are reached, for example a first step when the measured loss corresponds to 80% of the maximum blood loss and a second level to 90% so that the nurse can anticipate a risk for the patient. These warning signals then correspond to prevention signals indicating that special monitoring must be given to the corresponding patient.

It is thus understood that the monitoring device 1, described above, allows a constant monitoring of the state of the patient and the patient. level of risk incurred by the latter, greatly facilitating the task of the medical staff.

The invention also aims at protecting the method of implementation of the monitoring device 1, in which method the following steps are carried out:

a step of introducing data relating to the patient,

a step of measuring the blood losses in volume and in flow,

a step of transmitting the measured values,

a first step of comparing the results of the measurement step with a threshold value SI corresponding to a maximum theoretical blood loss,

a second step of comparing the results of the measuring step with a threshold value S 2 corresponding to a blood loss rate,

a step of generating an alert when one of the threshold values S1 or S2 is exceeded.

Advantageously, the aforementioned steps are restarted in an automatic sequence until triggering of a threshold value.

Of course, other features of the invention, within the reach of ordinary skill in the art could also be envisaged without departing from the scope of the invention as defined in the claims below. By way of example, in another advantageous embodiment, provision is also made for generating an alert when the measured fluid loss corresponds to a percentage of the capacity of the pocket 7, making it possible to indicate to the nurse that pocket 7 must be replaced.

Claims

1. Device for monitoring the loss of blood fluid from a patient comprising a central unit (2), at least one peripheral device (3) comprising weighing means (4) and means for storing (5) said fluid, and signal transmission means (11) between the peripheral (3) and the central unit (2), characterized in that the device comprises patient data input means (8) and processing means (13) combining the introduced patient data with the blood fluid loss volume and flow data to determine at least one level of risk.

2. Monitoring device according to claim 1, wherein the data input means (8) relating to the patient comprise a keyboard (9) and a display (10) arranged at the level of the central unit (2) and / or a control terminal

(12).

3. Monitoring device according to claim 2 wherein the processing means

(13) are arranged at the central unit (2).

4. Monitoring device according to any one of the preceding claims wherein the processing means (13) calculate a first threshold value Si corresponding to the theoretical maximum blood loss (PST) according to the data entered relative to the patient and compares this first threshold value SI to the data relating to the loss of body fluid measured by the means of weighing ().

5. Monitoring device according to claim 4 wherein the processing means (13) comprise a second threshold value S2 corresponding to a loss rate and compares this second threshold value S2 to the loss rate measured by the weighing means.

6. Monitoring device according to. claim 5 comprising alarm means (21) for generating an alarm when the first or second threshold value is exceeded.

7. Monitoring device according to claim 6 wherein the alarm means (21) can generate a first alarm signal when one of the threshold values, SI or S2, is exceeded and then at least a second signal when one of the values threshold is exceeded by more than a given percentage K of said value.

8. Monitoring device according to any one of claims 4 to 7 above wherein the first threshold value SI corresponds to the theoretical maximum blood loss (PST) calculated according to the formula of GROSS or BOURKE

9. Monitoring device according to any one of claims 4 to 7 above wherein the first threshold value SI corresponds to the theoretical maximum blood loss (PST) calculated according to the following formula: PST = 0.7 * weight * (Hteprop - Htemin) / Htep.

10. Method of monitoring loss of blood fluid implementing the device according to any one of the preceding claims wherein the following steps are carried out:

a step of introducing data relating to the patient,

a step of measuring blood losses in volume and in flow,

a step of transmitting the measured values,

a first step of comparing the results of the measuring step with a threshold value SI corresponding to a maximum theoretical blood loss, a second step of comparing the results of the measurement step with a threshold value S 2 corresponding to a flow rate of blood loss,

a step of generating an alert when one of the threshold values SI or S2 is exceeded.

11. The monitoring method according to claim 10 wherein the steps are restarted in an automatic sequence until one of the threshold values SI or S2 is triggered.