RU2622607C2 - Method for patient stress level monitoring - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: skin conductivity is registered, measured and analysed. The following is determine based on conductivity indicators in dynamics: stress reaction intensity, stress cumulative effect and the degree of stress tension of the organism during the period of continuous monitoring. The stress reaction intensity is determined by averaging conductivity frequencies fluctuations for an interval of time of not less than 3 minutes but not more than 5 minutes. The stress cumulative effect is determined by multiplying the sum of the stress reaction intensity values that exceed the boundary value by the time during which the stress reaction intensity exceeded the boundary value. The stress intensity degree of the organism is determined by multiplying the ratio of stress cumulative effect and the maximum possible stress cumulative effect of this patient by the ratio of time during which the stress reaction intensity exceeded the boundary value and the period of continuous monitoring. The boundary value of skin conductivity frequency fluctuations, reflecting the stress reaction manifestation, corresponds to 0.11 peak/s. Further, the level of stress is determined based on the stress reaction intensity, stress cumulative effect and the degree of stress intensity of the organism in dynamics.

EFFECT: method allows to monitor the stress level with high accuracy and reliability by determining the most significant indicators of skin conductivity in dynamics.

3 cl, 6 dwg, 3 ex

Description

The invention relates to medicine, namely to methods for diagnosing the condition of patients by indicators of skin conduction, and can be used in intensive care units and intensive care units (ICU) to monitor the level of stress, including pain, in newborns, infants and young children, with which verbal contact is difficult or impossible, and patients of other age groups who are in an unconscious state.

Pain syndrome is considered as one of the factors of stress and the development of the general adaptation syndrome (see the publication by G. Selye, 1960). The International Association for the Study of Pain (IASP) defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage”; “Pain is always an unpleasant sensation that is associated with emotional experiences.”

Currently, in clinical practice, stress assessment, including pain, in nonverbal patients and in patients in an unconscious state, is carried out using visual-analogue scales. The assessment of pain on visual scales is subjective and largely depends on the professional level of the medical staff, and is also unsuitable for hours and continuous monitoring in real time. At the same time, methods that are more reliable in assessing stress cannot be used to determine indicators of hormonal regulation, metabolism and homeostasis, because they are invasive and not available for routine use. Basically, after admission to the ICU, the monitoring of nonverbal patients is carried out by a visual method at intervals of 2, 4 and 24 hours.

It is known that skin conduction (electrodermal diagnostics) is an objective sensitive indicator of the physiological (physical) and psychoemotional state of a person under stress, and the response parameters of skin conduction, also called skin-galvanic reaction (RAG), have been used since the late 90s of the last century to assess psycho-emotional and physiological stress.

In recent years, the legality of the use of skin conductivity indicators in assessing pain stress has been disclosed and confirmed in numerous literature sources, and the most reliable criterion for the intensity of a stress reaction is the frequency of fluctuations (fluctuations) in skin conductivity (peak / sec.) (See Hellerud B.C. publications , Storm H., 2002; Anand KJS, et al., 2007; T. Ledowski et al., 2007; N.I. Melnikova et al., 2011; O.Yu. Terlyakova et al., 2013).

The prior art methods for determining the level of stress, including pain, based on registration, measurement and analysis of skin conductivity (US 8512240, A61B 5/00, publ. 08/20/2013; KR 20130016708, A61B 5/05, publ. 18.02 .2013; US 2015018707, A61B 5/053, publ. 15.01.2015). However, the known methods cannot provide a reliable assessment of the level of pain stress in a patient, since the obtained data are not the result of a comprehensive analysis of the manifestation of stress reactions in a patient.

Closest to the claimed method is a method of monitoring skin conduction for assessing pain intensity, including sampling and saving threshold data, a step-by-step monitoring process, including: continuous or time-discrete measurement of skin conductivity, storing in memory of measurement results, obtaining analysis results of current and previous conductivity measurements; these analysis results consist of fluctuations in the frequency and amplitude of the conduction signal in a time interval containing recently elapsed time points, where the analysis results with respect to frequency are obtained by calculating the maximum values contained in the indicated time interval, comparing the obtained analysis results with threshold data and determining increased pain the patient's response in terms of frequency and amplitude of skin conduction (US 6571124, A61B 5/053, publ. 05.27.2003).

This method has found practical application and is implemented in the device "Med-Storm Stress Detector" ("Med-Storm Pain Monitor"). Studies on the clinical application of this method have revealed both positive (see publications Ledowski et al., 2006; Ledowski et al., 2007; Hullett et al., 2009) and negative results (see publications by E.K. Choo et al ., 2010; E.K. Choo, 2013, Savino F et al., 2013; Ledowski T, et al., 2009; Czaplik M, et al., 2012). In this case, the positive results were obtained by the authors in those cases when the frequency of the peaks per second was averaged over 5-15 seconds, and in contrast, the averaging of the peak frequencies over 30-60 seconds led to negative results. The contradictory results of the clinical application of the proposed method for assessing the intensity of pain can be explained by the fact that this method of determining the intensity of pain can be effective only for assessing short-term pain stimuli during painful manipulations, for example, an injection with a scarifier when taking blood samples, as well as the presence of artifacts associated with a possible the influence of movements and temperature on the measurement results. In addition, the method estimates only the intensity of pain stimuli, but does not take into account their duration and the possible cumulative effect, which does not allow one to get an idea of the tension of the body's compensatory systems, i.e. Assess the severity of stress.

It is known that stress, including pain, is the trigger in the development of a complex protective reaction of the vegetative type and is accompanied by stress of various functional systems of the body: respiration, blood circulation, hormonal regulation, metabolism and homeostasis.

Since the end of the 70s of the last century, it is known that in conditions of physical (physiological) stress, at least 3 minutes are required to achieve a Steady State in changes in physiological parameters. Each of the mechanisms of the stress response has a compensatory limit, and if the stressor does not stop, a cumulative effect is observed, tension increases, which can lead to overstrain and distress, and, accordingly, to dysfunctional and pathological conditions.

The intensity of pain, as one of the factors of stress, does not fully reflect the state of tension in the body, because the magnitude of the response of physiological systems is determined not only by the intensity, but also by the duration of the action of stressors and the cumulative effect of the negative effects of repeated stress stimuli. Short-term severe stress causes an urgent short-term response and after the termination of the stressor, physiological parameters quickly return to normal values. In contrast, less intense, but prolonged stress leads to the depletion of the body's defenses. From the standpoint of physiology, the duration of stress is more important than its intensity. The longer the stress factors act, the more likely the state of overvoltage and, accordingly, the more likely the development of distress.

The objective of the claimed invention is the creation of an objective and affordable way to monitor the level of stress in newborns, infants and patients in an unconscious state, devoid of the disadvantages of the above analogues, as well as expanding the arsenal of funds for this purpose.

The technical result of the claimed invention is to increase the diagnostic reliability (objectivity and reliability) of a method for monitoring stress levels, including pain, in newborns, infants and young children, as well as in patients in an unconscious state.

Identification of the level and dynamics of the stress response is necessary for the timely prevention of overstrain of the functional systems of the body and the prevention of the development of distress, the appointment of appropriate therapeutic and preventive measures and the determination of the effectiveness of their use.

The claimed technical result is achieved due to the fact that in the method for monitoring the level of stress in a patient, including recording, measuring and analyzing skin conductivity indicators, the following parameters are determined from the skin conductivity indicators in dynamics: stress reaction intensity, cumulative stress effect and the degree of stress of the body over the period continuous monitoring, and the intensity of the stress reaction is determined by averaging the frequencies of fluctuations in skin conduction over a time interval of e less than 3 minutes but not more than 5 minutes; the cumulative effect of stress is determined by calculating the product of the sum of the values of the intensity of the stress reaction exceeding the boundary value by the time during which the intensity of the stress reaction exceeds the boundary value; the degree of stress intensity of the body is determined by calculating the product of the ratio of the cumulative effect of stress to the maximum possible cumulative effect of stress in a given patient and the ratio of the time during which the intensity of the stress reaction exceeded the boundary value to the period of continuous monitoring; while the boundary value of the frequency of fluctuations in skin conduction, reflecting the manifestation of a stress reaction, corresponds to 0.11 peak / sec; Further, according to the values of the intensity of the stress reaction, the cumulative effect of stress and the degree of stressful tension in the body, the level of stress is determined in dynamics.

It is advisable that the time interval for averaging the frequency values of fluctuations of the skin conductivity is 3 minutes.

It is advisable that the period of continuous monitoring is at least 60 minutes.

Improving the objectivity and reliability of determining the level of stress, including pain, in patients staying in ICU, is achieved through the use of new estimated indicators of the level of stress and analysis of their dynamics.

The claimed method for monitoring the level of stress in a patient, including pain, involves measuring and analyzing skin conductivity in real time and is characterized by the fact that the intensity of pain stress (stress reaction), its duration, and the cumulative effect of stress are determined by the indicators of skin conductivity and the degree of stressfulness of the body during the period of continuous monitoring.

Continuously in real time using the device for recording electrodermal activity, the frequency of fluctuations in skin conduction is recorded during the period of continuous monitoring. The continuous monitoring period should preferably be at least 60 minutes (to use the developed rating scales). The obtained values are automatically averaged for every 3 minutes of monitoring (a 3-minute period is accepted as the standard). The fluctuation frequency values averaged over 3 minutes reflect the intensity of pain stress.

Then, the averaged values of the frequencies of fluctuations of the skin conductivity are sampled in excess of the boundary value of the frequency of fluctuations of the skin conductivity. The boundary value of the frequency of fluctuations in skin conduction, which is a manifestation of a stress reaction, lies in the range from 0.08 to 0.11 peaks / s, and preferably is 0.11 peaks / s. Next, determine the number of stress stimuli for the monitoring period by determining the number of values of the frequency of fluctuations of skin conduction, exceeding the boundary value. Determination of the duration of stress for the monitoring period is carried out by calculating the product of the number of stress stimuli by the set (3-minute) time interval.

As an indicator of the cumulative effect of stress, the product of the sum of the values of the intensity of the stress reaction exceeding the boundary value is calculated by the duration of the stress for the period of continuous monitoring.

DIS = (IP ₁ > 0.11 + IP ₂ > 0.11 + IP ₃ > 0.11 + ... IP _n > 0.11) * t * Q,

Where:

DIS is an indicator of the cumulative effect, conv. units;

IP ₁ ... IP _n - stress stimulus intensity in excess of 0.11 peak / s;

t = 3 minutes;

Q - the number of repetitive stress stimuli for the period of continuous monitoring.

For an integral assessment of the degree of stress of an organism, the product of the ratio of the cumulative effect of stress to the maximum possible cumulative effect of stress and the ratio of the duration of stress to the period of continuous monitoring is calculated.

DS = (DISn / DISmax) * (T ₁ / T ₂ ) × 100,

Where:

DS is the degree of stress tension,%;

DISn is an indicator of cumulative effect, conv. units;

DISmax - an indicator of excessive cumulative effect, conv. units;

T ₁ - the duration of stress, min;

T ₂ - the period of continuous monitoring, min.

To develop the rating scales used in the claimed method, a 60-minute interval was taken as a standardized time interval during which continuous monitoring of the patient's condition is carried out. For hours of monitoring the condition of patients in the ICU departments, this unit of measurement is the most optimal. If other standardized time intervals are needed, appropriate rating scales should be developed.

To eliminate artifacts in changes in skin conduction, the patient’s body temperature is monitored. In addition, in the process of observation, video monitoring is additionally carried out, which allows determining the level of stress according to visual scales for assessing stress.

To determine the patient's stress level, scales are used to assess the intensity of stress, its cumulative effect and the degree of stress of the body. According to the developed scales, the stress level is determined in points and verbal characteristics according to the corresponding numerical values of stress intensity, its cumulative effect and the degree of stress of the body.

In FIG. 1 shows a scale for assessing the intensity of stress (stress reactions) in newborns.

In FIG. 2 presents a scale for assessing the cumulative effect of stress in newborns.

In FIG. 3 presents a scale for assessing the degree of stress of the body in newborns.

To develop scales for assessing the level of stress and its dynamics in newborns, 3423 measurements of the frequency of fluctuations in skin conductivity averaged over 3 minutes were performed over 179 hours of continuous monitoring in 56 newborns in the postoperative period. The intensity value equal to 0.11 peak / s was taken as the boundary value, and values exceeding this level were included in the sample. The development of rating scales was carried out using the generally accepted method of mathematical statistics on sigmal deviation.

To verify the operability of the claimed method, 14 newborns were monitored during the first two days of the postoperative period. The condition of the children after surgery was assessed as satisfactory, respiratory and cardiovascular disorders were not observed. In order to ensure the absence of artifacts related to the effect on the characteristics of skin conduction, the group of the examined included newborns whose body temperature was in the range of 35.1-36.8 °. Visual assessment of the condition was carried out 2, 4 and 24 hours after the arrival of newborns in the intensive care unit. To test the effectiveness of the application of the developed method for assessing stress, newborns were connected to the device for a period during which visual monitoring of the newborn was not carried out, anesthetic and other benefits were not applied, the alarm was turned off and video monitoring was not carried out. Assessment of the dynamics of the condition of newborn patients by skin conductivity was carried out using software developed for this purpose. The intensity indicators (IP peak / s), the cumulative effect (DIS conv. Units) and the stress index (DS conv. Units) were calculated. The data analysis was carried out retrospectively, pharmacological correction of the condition of newborns according to the indications of the system was not carried out, due to the lack of permission for use in practice at the time of clinical testing (RU Roszdravnadzor).

Example 1

Newborn A., full-term, 28 days old, performed laparoscopic pylorotomy. The patient was monitored for 14 hours (from 20 h 09 min to 10 h 24 min). During the first 7 hours of monitoring (from 20 h 09 min to 02 h 06 min), a short-term (within 3-10 min.) Increase in the frequency of fluctuations in skin conduction was observed. The intensity values (IP) were in the range of 0-0.11 peaks / s, the cumulative effect (DIS) and the voltage index (DS) did not exceed 6.0 conv. units and 0.3%, respectively, reflecting the absence of stress or significant discomfort. Further, during the monitoring process and until the observation was terminated (from 23 h 09 min to 10 h 15 min), a manifestation of stress (pain) was observed in increasing dynamics, which was characterized by an increase in the number of stressful stimuli, their intensity and duration. The stimulus intensity corresponded to the range from 0.15 to 0.48 peak / s, the cumulative effect index consistently increased from 10 to 88 conv. units, the stress indicator from 0.5% increased to 4.2%, with an increase in the number of pain stimuli from 4 to 12 per hour at the time of disconnection of the newborn from the monitor. The observation results revealed in this patient an increase in the cumulative effect of stress at night while maintaining negative dynamics until the observation was completed. In this case, the absolute values of the studied parameters, in accordance with the developed assessment scales, indicated an insignificant stress of the body, taking into account the intensity, duration and cumulative effect of stress. In FIG. 4 shows the dynamics of the studied parameters for the entire monitoring period and the values of the indicators at the time of disconnection of the newborn from the monitor.

Example 2

Newborn V., full-term, age 14 days, performed laparoscopic pylorotomy. The patient was monitored from 12 hours 57 minutes to 10 hours 45 minutes the next day, i.e. within 21 hours 51 minutes. The first 7 hours of observation, i.e. until 19 hours 51 min, significant changes in the parameters of skin conductivity were not observed and their values for intensity (IP) were in the range of 0-0.06 peak / s, the cumulative effect (DIS) and stress indicator (DS) indicated the absence of any stress or discomfort. From 19 hours 54 minutes to 20 hours 54 minutes, a manifestation of a stress reaction was observed, which was characterized by consistent pain stimuli for 30 minutes. IP values ranged from 0.15 to 0.33 peak / s with a subsequent decrease by the end of the current hour to 0.01-0.07 peak / s, which was accompanied by a slight cumulative effect of DIS - 53 conv. units, and the strain rate DS - 8%, which indicated a slight tension, probably associated with discomfort or mild pain. From 22 hours 18 minutes to 23 hours 51 minutes, a second wave of stress response was observed, which was characterized by an increase in the number of pain stimuli up to 16, IP values from 0.18 to 0.42 peak / s, and the cumulative effect indicator DIS - 142 conv. units and the DS stress indicator was 37%, which reflected the cumulative effect of pain stress increasing to a high level and the body tension was above average. In the future, the condition of the newborn tended to normalize, but after 03 hours 06 minutes a third wave of pain-stress reaction was observed, which persisted until 04 hours 42 minutes. 14 pain stimuli were noted with IP values in the range of 0.12-0.35 peak / s, DIS - 136 srvc. units and DS - 31%, which was characterized above the average level of the cumulative effect of stress and the average voltage of the compensatory systems of the body. The next 6 hours of monitoring revealed a normalization of the patient's condition, and no negative changes from the studied parameters were observed. Immediately before disconnecting the newborn from the monitor, another manifestation of the pain stress reaction began, i.e. IP rose to 0.43 peak / s, DIS to 254 srvc. units, DS - 82%, the observation was interrupted due to the need for a medical procedure. In FIG. Figure 5 shows the dynamics of the studied parameters for the entire observation period and the absolute values at the time the newborn was disconnected from the monitor.

Example 3

Newborn C, full-term, 28 days old, plastic hernia ring due to inguinal-scrotal hernia. Monitoring of the patient's condition began at 13 hours 57 minutes and until 21 hours 15 minutes. All studied parameters were within the values indicating the absence of pain or discomfort. However, from 21 hours 15 minutes of the ball revealed a slight stress reaction, which until 21 hours 54 minutes was characterized by IP values in the range 0.13-0.32 peak / s, DIS - 42 srvc. units, DS - 5.4%. Further observation showed a gradual increase in pain stress to a level above the average, as indicated by IP values in the range of 0.21-0.39 peak / s, an increase in DIS to 152 conv. units and DS - 36.7%, the number of pain stimuli increased during the development of a stress response from 8 to 15 per hour. Over the next 4 hours of monitoring, a gradual decrease in pain stress was observed and further, from 03 hours 57 minutes, pain stimuli were not observed. In FIG. Figure 6 shows the dynamics of the studied parameters for the entire observation period and the absolute values at the time the newborn was disconnected from the monitor.

Thus, the developed method is a reliable way to monitor the level of pain stress in patients with impossible or difficult verbal contact.

Claims (8)

1. A method for monitoring the level of stress in a patient, including recording, measuring and analyzing indicators of skin conductivity, characterized in that the parameters of skin conductivity in the dynamics determine: the intensity of the stress reaction, the cumulative effect of stress and the degree of stress of the body over a period of continuous monitoring, moreover, the intensity of the stress reaction is determined by averaging the frequency of fluctuations of the skin conductivity over a time interval of at least 3 minutes, but not more than 5 minutes; the cumulative effect of stress is determined by calculating the product of the sum of the values of the intensity of the stress reaction exceeding the boundary value by the time during which the intensity of the stress reaction exceeds the boundary value; the degree of stress intensity of the body is determined by calculating the product of the ratio of the cumulative effect of stress to the maximum possible cumulative effect of stress in a given patient and the ratio of the time during which the intensity of the stress reaction exceeded the boundary value to the period of continuous monitoring; while the boundary value of the frequency of fluctuations in skin conduction, reflecting the manifestation of a stress reaction, corresponds to 0.11 peak / s; Further, according to the values of the intensity of the stress reaction, the cumulative effect of stress and the degree of stressful tension in the body, the level of stress is determined in dynamics. 2. The method according to p. 1, characterized in that the time interval for averaging the frequency values of fluctuations of the skin conductivity is 3 minutes. 3. The method according to any one of paragraphs. 1-2, characterized in that the period of continuous monitoring is at least 60 minutes.

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