RU2623148C2 - Method for estimation of patient state severity and risk of lethal outcome based on phenylmocal acid level in blood - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: phenyl-lactic acid (PLA) concentration in patients' blood is quantitatively determined. Patients' state is determined as stably severe in cases when the PLA level in blood is increased no more than 2 times compared to the average physiological value (risk of death is <25%). A very severe state is determined if the PLA level in blood is increased 2-3 times (risk of death is 25-50%). An extremely severe state - in cases when the PLA level in blood is increased more than 3 times (risk of death is >50%).

EFFECT: use of the method allows to accurately assess the severity of patient's state and the risk of death.

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Description

The technical field where the use is intended

The invention relates to the field of clinical laboratory diagnostics and can be used in clinical practice to assess the severity of the condition and predict the outcome of intensive treatment in anesthesiology-resuscitation and related medical specialties.

Assessing the severity of the condition of patients is an integral part of the diagnostic process in the intensive care units. Based on it, risk groups and the forecast of the course of critical conditions are determined, and the effectiveness and quality of the medical care provided is assessed. Formalization of the severity of the condition of patients is a necessary tool in the planning and conduct of medical research. The most common approach to objectifying the severity of the condition of patients is the development and improvement of multi-parameter scales of severity.

Among clinical scales, the most widely used system of acute physiology and assessment of chronic health (Acute Physiology and Chronic Health Evaluation - APACHE) (Knaus, WA APACHE II: a severity of disease classification system. / WA Knaus, EA Draper, DP Wagner, JE Zimmerman / / Crit. Care Med. - 1985. - Vol. 13. - No. 10. - P. 818-829). Good reproducibility of the results made this system of assessing the severity of the condition one of the most popular and validated in the world. Other multi-parameter methods for assessing the severity of the condition are known (Method for assessing the severity of the condition and prognosis of the outcome of a disease in patients with urgent surgical pathology of the abdominal organs, patent RU 2007122617 A; Method for assessing the severity of the condition of sick children, patent RU 2166761 C; Grebenyuk, VV System assessment of the severity of the condition of patients with abdominal sepsis. / VV Grebenyuk, N.V. Yusan // Pacific Medical Journal, - 2011. - No. 3. - pp. 85-87; Arzumanyan, V.M. and super slow biopotentials in the prognosis of mortality in resuscitation patients: thesis ... Candidate of Medical Sciences: 14.00.37. / Arzumanyan V.M. - Rostov-on-Don, 2007. - 120 p.), however, due to the large number of evaluated parameters, these methods are not widespread. In order to optimize the assessment of the severity of the condition, the search for individual biochemical markers continues, on the basis of which it is possible to develop simpler, one-parameter methods for assessing the severity of the condition and predicting the course of critical conditions.

Thus, the researchers are faced with the task of developing simpler methods for assessing the severity of the condition. The problem is solved by a method of assessing the severity of the condition and the risk of death of patients by the level of phenyl lactic acid in the blood, which consists in the fact that the concentration of phenyl lactic acid (PMA) in the blood of patients is determined and the condition of the patients is determined to be stably severe in cases where the level of PMA in the blood is increased no more than 2 times of the average physiological value (risk of death <25%), extremely severe in cases where the level of PMA in the blood is increased 2-3 times (risk of death 25-50%), and extremely severe - case If FMC blood increased more than 3 times (risk of death> 50%).

The method can be implemented using standard laboratory equipment with the involvement of personnel whose qualifications do not exceed the level of a specialist in the field of chemical, biochemical, enzyme immunoassay. In the present study, the concentration of PMA in the blood was measured by gas chromatography (gas chromatography with flame ionization detection), however, the method according to the invention also includes determining the concentration of PMA in the blood and its components (plasma, serum) by any other method.

The method of gas chromatographic determination was as follows. 800 μl of water for injection, 200 μl of blood serum and 10 μl of methanol (Fluka, USA) with 400 ng of 3,4-dihydroxybenzoic acid (Acros Organics, USA) (3,4-DHA, internal) were placed in a glass tube standard). To denature and precipitate the protein, 0.5 g of solid sodium chloride and concentrated sulfuric acid were added to the test tube to pH 2. Then, organic compounds (3 × 1 ml) were extracted three times with diethyl ether (Khimmed, Russia). To obtain trimethylsilyl (TMS) derivatives, the resulting ether extract was evaporated to dryness at 40 ° C. The dry residue was kept under a lid with 20 μl of N, O-bis (trimethylsilyl) trifluoroacetamide (Fluka, USA) at 80 ° С for 15 min. Then, the resulting mass was brought to room temperature and diluted with 80 μl of n-hexane (Ekos-1, Russia). The analysis of PMA in serum samples was carried out on a Crystal 5000.2 domestic gas chromatograph (Chromatek, Russia) equipped with a flame ionization detector.

Chromatographic separation was performed on a CP SIL 5CB quartz capillary column with a diameter of 0.32 mm, a length of 30 m, and a stationary phase layer thickness of 0.25 μm. The volume of the analyzed sample is 2 μl. Temperature conditions: evaporator temperature 270 ° C, initial column thermostat temperature 80 ° C, holding time 4 min, then heating to 240 ° C at a speed of 7 degrees / min and then to 270 ° C at a speed of 15 degrees / min, temperature control at 270 ° C until the end of the analysis. The carrier gas is helium, the flow rate through the column is 1.2 ml / min, the flow division is 1:25; total analysis time - 30 minutes The amount of metabolite to be determined was evaluated by comparing its peak area with the peak area of the internal standard. Retention time: PMK - 19.16 min.

SUMMARY OF THE INVENTION

For an objective assessment of the severity of the condition and the risk of death in patients (mainly in the intensive care unit and intensive care unit), a concentration of phenyl lactic acid (PMA) in a blood sample is quantified. In such patients, the concentration of PMA in the blood significantly exceeds the average physiological level in healthy people (0.6 μmol / L when assessed by gas chromatography with flame ionization detection) and correlates with the severity of the condition. The starting material for the analysis is blood. In the present study, the blood was centrifuged to obtain serum and subsequent gas chromatographic analysis of trimethylsilyl derivatives of phenyl lactic acid in it. Also, the concentration of PMA in the blood can be measured by any other available method. The risk of death and severity of the condition were determined on the basis of the logistic regression equation, in which the outcome of treatment of patients was tested as a dependent variable: 0 - the patient survived (n = 34), 1 - the patient died (n = 24)). The condition of patients is determined stably severe in cases where the level of FMC in the blood is increased no more than 2 times from the average physiological value (risk of death <25%), extremely severe - in cases where the level of FMC in the blood exceeds the average physiological level from 2 to 3 times (the risk of death 25-50%), and extremely severe - in cases where the level of PMK in the patient’s blood is increased more than 3 times (risk of death> 50%).

Example 1

Patient T-na, 48 years old, 02/08/14, was admitted to the intensive care unit and intensive care with the main diagnosis "Colorectal tumor complicated by perforation. Local peritonitis "after emergency surgery" Laparotomy. Hemicolectomy. Formation of intestinal stoma. Remediation, drainage of the abdominal cavity ”on prolonged mechanical ventilation. At the time of the examination, the severity score on the APACHE II scale was 4 points. According to gas chromatographic analysis, the level of PMA in the blood serum was 0.63 μmol / L (risk of death <25% - favorable prognosis) (Fig. 1). In accordance with the claims, the patient’s condition upon admission to the intensive care unit is defined as stably severe (the level of PMK in the patient’s blood is increased no more than 2 times from the average physiological value). Against the background of complex treatment, the patient's condition without negative dynamics. On the 3rd day, the patient was transferred from the intensive care unit to the specialized department.

Example 2

Patient Zh.-va., 69 years old, March 8, 2014 was admitted to the intensive care unit and intensive care with the main diagnosis: “A tumor of the colon complicated by perforation and acute bowel obstruction. Local peritonitis. Pneumonia ”after an emergency surgery“ Laparotomy. Hemicolectomy. Formation of intestinal stoma. Remediation, drainage of the abdominal cavity. " At the time of the examination, the APACHE II severity score was 12 points. According to gas chromatographic analysis, the level of PMA in the blood serum was 5.77 μmol / L (risk of death> 50% - poor prognosis) (Fig. 2). In accordance with the claims, the condition of the patient upon admission is determined to be extremely severe (the level of PMK in the patient’s blood is increased more than 3 times in comparison with the average physiological value). Despite the treatment, the patient progressed to multiple organ failure and developed a lethal outcome on day 4.

Thus, the method according to the invention allows to objectively assess the severity of the condition of patients and the prognosis of intensive treatment. According to the statistical calculations, the monoparametric method based on FMC in its predictive accuracy (AUC 0.886) is not inferior to the multiparameter scale APACHE II (AUC 0.897) (ΔAUC 0.011; p> 0.05).

List of abbreviations:

AUC - area under roc curve (area under the ROC curve);

PMA - phenyl lactic acid.

Brief Description of the Drawings

FIG. 1. The level of phenyllactic acid in the blood serum of patient T-na (48 years) according to gas chromatography, μmol / L (Example 1), in comparison with the physiological level of FMC.

FIG. 2. The level of phenyllactic acid in the blood serum of the patient W (69 years) according to gas chromatography, µmol / l (Example 2), in comparison with the physiological level of FMC.

Claims (1)

A method for assessing the severity of a patient’s condition and the risk of fatal outcome by the level of phenyllactic acid in the blood, which consists in the fact that based on the concentration of phenyllactic acid (PMA), the condition of the patients is determined to be stably severe in cases where the level of PMA in the blood is increased no more than 2 times from of average physiological significance (risk of death <25%), extremely severe - in cases where the level of FMC in the blood is increased by 2-3 times (risk of death is 25-50%), and extremely severe - in cases where the level of FMC in blood elevated more than 3 ra for (risk of death> 50%).

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