Heart Surgery Patients Research Articles

The Influence of Early Mobilization Protocol on Post Open Heart Surgery Patients Length of Stay in Surgical ICU

The Influence of Early Mobilization Protocol on Post Open Heart Surgery Patients Length of Stay in Surgical ICU

Our ultrafiltration experience in open heart surgery patients with chronic renal failure

Our ultrafiltration experience in open heart surgery patients with chronic renal failure

The functional capacity of the patients after open heart surgery following physiotherapy utilizing inspiratory muscle training

Background: Post-operative pulmonary dysfunction is common after open heart surgery. This causes impairment in the routine activities of an individual. Exercise rehabilitation may benefit in open heart surgery patients, improving their exercise capacity. Objective: The objective of the study was to assess and compare functional capacity in open heart surgery patients following conventional physiotherapy (CP), and CP plus inspiratory muscle training (IMT). Materials and Methods: In this prospective randomized control study, participants were taken from cardiac hospital using balance block computer generated randomization method. There were 102 participants, 52 in Group-A and 50 in Group-B. Group-A has been given CP and the Group-B has been given conventional plus IMT exercise by Pressure Threshold IMT instrument. For the functional capacity measurement, 6 minute walk test (MWT) and incentive spirometry (IS) was used at pre-operative, “at discharge” and at “1st follow-up” of patients. Results: Addition of IMT exercises to the conventional physiotherapy did not show statistically significant difference in functional capacity after open heart surgery. Though the component of functional capacity- 6MWT showed an incremental change which was statistically significant within the groups (P < 0.05). Conclusion: No any significant difference was found in functional capacity in CP and conventional plus inspiratory muscle trainer group in “pre-operative,” “at discharge” and “1st follow-up,” in open heart surgery patient.

Psychosocial Factors Associated with Transfer Anxiety among Open Heart Surgery Patients Transferred from the Intensive Care Unit to the General Ward

Introduction: Patient’s transfer from the intensive care unit (ICU) to the general ward indicates their improving health status. However, the transfer produces anxiety when patients enter an unfamiliar environment with different care protocols and circumstances. Objectives: This study aimed to examine the level of ICU transfer anxiety among open heart surgery patients and determine the psychosocial factors associated with ICU transfer anxiety among open heart surgery patients. Methods: Data were collected in a cardiac center in Kathmandu City, Nepal among 95 open heart surgery patients within 24 hours of their transfer from an ICU to a general ward. The study used four self-reported questionnaires, namely the modified Mishel Uncertainty in Illness Scale for Adults, modified Brief COPE Inventory, Nurses’ Support Questionnaire, and State Anxiety Inventory. Results: Fifty-two patients (54.7%) had a high level of transfer anxiety. Spearman’s rank correlation showed that uncertainty in illness, coping, and nurses’ support were significantly related to transfer anxiety (p < 0.001). Conclusion: The results of this study suggest nurses to address uncertainty in illness of the patients, improve their coping abilities, and provide need-based nursing support to them during the transitional phase. Besides, clinicians and governmental agencies should contribute to implication of transitional guidelines, which can reduce transfer anxiety and promote health and recovery of the patients.

Applying Cardiac Rehabilitation Exercise Protocol to Reduce Post-operative Cardio-Pulmonary Complications among Open Heart Surgery Patient's

Background: Cardiac surgery is a complex procedure that is resulting in a higher incidence of com­plications and tends to significantly decrease the potential for recovery. It is essential for the nurse to anticipate the treatment of complications so that appropriate interventions are initiated in order to ensure a positive outcome for patients. Aim of the Study:To evaluate the effect of applying cardiac rehabilitation exercise protocol for open heart surgery patient's to reduce post-operative cardio-pulmonary complications. Research Design: Quasi-experimental research design was utilized in the current study. Subjects: A purposive sample including 60 patients male and female, classified equally into two equal groups; study group (n= 30) and control group (n= 30). Setting: This study carried out in the inpatient cardiac surgery department of Cardio-thoracic Surgery Hospital at New Minia City. Tools of Data Collection: Three tools were utilized in collecting data. Tool I: Patient Assessment Sheet, Tool II: Cardiac Rehabilitation Exercise Checklist. Tool Ш: Cardiopulmonary Complications Assessment Sheet. Results: Current study findings revealed that the study group had a lower incidence of cardiac and respiratory complications (30%, and 3.3%) respectively compared to (46.7% and 26.7%) for the control group and there is a statistical significance differences were detected between the two groups. Conclusion: The current study findings concluded that the cardiac rehabilitation exercise protocol in the form of deep breathing, incentive spirometer, coughing and early ambulation induces significant improvement in reducing the risk of post-operative cardio pulmonary complications. Recommendations: Hospitals should recommend implementing cardiac rehabilitation exercise protocols as a routine hospital policy among all cardiac surgical patients in all age groups

Diagnostic accuracy of computed tomography angiography for the exclusion of coronary artery disease in candidates for transcatheter aortic valve implantation

Coronary CT angiography (CTA) is currently considered a reliable method to exclude obstructive coronary artery disease (CAD) before valvular heart surgery in patients with low pretest probability. However, its role in excluding obstructive CAD before transcatheter aortic valve implantation (TAVI) is less well established. Single-center retrospective study where patients with severe symptomatic aortic stenosis underwent both CTA and invasive coronary angiography (ICA) as part of TAVI planning. CTA exams were conducted on a 64-slice dual source scanner, with a median interval of 45 days to ICA (IQR 25–75 [13–82]). In both tests, obstructive CAD was defined as a ≥50% stenosis in an epicardial vessel ≥2 mm diameter. Per-patient, per-vessel and per-proximal segment analyses were conducted, excluding and including non-evaluable segments. The study included 200 patients (120 women, mean age 83 ± 6 years). The prevalence of obstructive CAD on ICA was 35.5% (n = 71). On a per-patient analysis (assuming non-evaluable segments as stenotic), CTA showed sensitivity of 100% (95% CI, 95–100%), specificity of 42% (95% CI, 33–51%), and positive and negative predictive values of 48% (95% CI, 44–51%) and 100% (95% CI, 92–100%), respectively. CTA was able to exclude obstructive CAD in 54 patients (27%), in whom ICA could have been safely withheld. Despite the high rate of inconclusive tests, pre-procedural CTA is able to safely exclude obstructive CAD in a significant proportion of patients undergoing TAVI, possibly avoiding the need for ICA in roughly one quarter of the cases.

Outcome of adult congenital heart disease patients undergoing cardiac surgery: clinical experience of dr. Sardjito hospital

BackgroundPatients with congenital heart disease require surgery to correct the cardiac defect they had in order to prevent heart failure. Unfortunately, data regarding outcome of adult CHD in Indonesia is still limited. In contrast with developed countries, many congenital heart surgery patients in developing countries are adults. The purpose of this study was to investigate the outcomes of cardiac surgery procedures among adult congenital heart disease patients, and what factors that might influence the outcome of surgery.MethodsA retrospective study was performed on adult congenital heart disease patients undergoing cardiac surgery at Dr. Sardjito Hospital between April 2018 and March 2019. Variables included in the study were demographic characteristics, laboratory test results, comorbidities, premedication, Cardiopulmonary Bypass (CPB) and ischemia duration were included in the analysis. Outcomes were in-hospital mortality, hospital length of stay, and ICU length of stay.ResultsA total of 25 congenital heart disease patients [19 Atrial Septeal Defect (ASD) patients, and 6 Ventricular Septal Defect (VSD) patients] underwent a cardiac surgery procedure at Dr. Sardjito Hospital during the study period. Mean age was 31 ± 14.92 years. The majority of patients had pulmonary hypertension. During the study period, none of the patients died during postoperative care in the hospital, mean hospital length of stay (LOS) was 8.35 ± 3.39 days and ICU LOS was 26.53 ± 11.33 h.ConclusionSurgery in adult patients with congenital heart disease may be successfully performed with low morbidity and mortality.

Outcomes of open heart surgery in patients with end-stage renal disease.

BackgroundCardiovascular diseases of chronic dialysis patients are often undertreated because of their higher surgical risk. This study aimed to assess mortality and morbidity after open heart surgery in chronic dialysis patients compared to those with normal renal function and identify risk factors for postoperative outcomes.MethodsWe retrospectively analyzed 2,432 patients who underwent open heart surgery from 2002 to 2017 and collected data from 116 patients (38 patients on dialysis and 78 age-, sex-, and diabetes mellitus status-matched control patients with normal kidney function). We assessed comorbidities, New York Heart Association (NYHA) class, laboratory data, surgical methods, and postoperative outcomes.ResultsThe dialysis group had more comorbidities, higher NYHA classes, and greater need for urgent surgeries compared to the control group. They exhibited significantly higher postoperative mortality (18.4% vs. 2.6%, P = 0.005) and more overall complications (65.8% vs. 25.6%, P < 0.001). Dialysis itself significantly increased relative risk for in-hospital mortality after adjustment. EuroSCORE II was not as useful as in the general population. Multivariate logistic regression analysis demonstrated that total (adjusted odds ratio [AOR], 10.7; P = 0.029) and in-hospital death risk (AOR, 14.7; P = 0.033), the durations of postoperative hospitalization (AOR, 4.6; P = 0.034), CRRT (AOR 36.8; P = 0.004), and ventilator use (AOR, 7.6; P = 0.022) were significantly increased in the dialysis group.ConclusionThe dialysis group exhibited a higher risk for mortality and overcall complications after open heart surgery compared to the patients with normal renal function. Therefore, the benefit of surgical treatment must be balanced against potential risks.

The number and phenotype of myocardial and adipose tissue CD68+ cells is associated with cardiovascular and metabolic disease in heart surgery patients

Background and aimsCD68+ cells are a potent source of inflammatory cytokines in adipose tissue and myocardium. The development of low-grade inflammation in adipose tissue is implicated in the pathogenesis of obesity-associated disorders including type 2 diabetes mellitus (T2DM) and cardiovascular disease. The main aim of the study was to characterize and quantify myocardial and adipose tissue CD68+ cells and adipose tissue crown-like structures (CLS) in patients with obesity, coronary artery disease (CAD) and T2DM. Methods and resultsSamples were obtained from the right atrium, epicardial (EAT) and subcutaneous adipose tissue (SAT) during elective heart surgery (non-obese, n = 34 patients; obese, n = 24 patients). Immunohistochemistry was used to visualize CD68+ cells. M1-polarized macrophages were visualized by immunohistochemical detection of CD11c. The proportion of CD68+ cells was higher in EAT than in SAT (43.4 ± 25.0 versus 32.5 ± 23.1 cells per 1 mm2; p = 0.015). Myocardial CD68+ cells were more abundant in obese patients (45.6 ± 24.5 versus 27.7 ± 14.8 cells per 1 mm2; p = 0.045). In SAT, CD68+ cells were more frequent in CAD patients (37.3 ± 23.0 versus 23.1 ± 20.9 cells per 1 mm2; p = 0.012). Patients having CLS in their SAT had higher average BMI (34.1 ± 6.4 versus 29.0 ± 4.5; p = 0.024). ConclusionsRegional-based increases in the frequency of CD68+ cells and changes of their phenotype in CLS were detected in obese patients and CAD patients. Therapeutic modulation of adipose tissue inflammation may represent a target for treatment of obesity.

Pilot study of viability in the use of cycle ergometer for upper limbs in the immediate postoperative period of cardiac surgery

INTRODUCTION: The use of a cycle ergometer for the upper limbs may contribute to maintain the functional capacity in patients after heart surgery (HS). OBJECTIVES: To investigate the cardiorespiratory responses of HS patients receiving or not vasoactive drugs (VADs) during the realizations of cycle ergometer for upper limbs, verifying the incidence of loss of radial arterial catheter or of steel wire fractures in the sternum. MATERIAL AND METHODS: A pilot study involving 26 patients divided in 2 groups. Group CO: no use of VADs (13 patients, age: 57±12 years, 09 male) and VAD group: (13 patients, age: 61±10 years, 07 male), submitted to HS, which on the first postoperative day (1stPO) performed the cycle ergometer for upper limbs. The parameters evaluated during the exercise were heart rate (HR), oxygen saturation (SpO2), dyspnea, fatigue of upper limbs and mean arterial pressure (MAP). The incidence of losses of the radial artery catheter and of steel wire fractures in the sternum was calculated. Statistical analysis adopted one-way or two-way analysis of variance, with post hoc from Newman Kauls or Scheffé, when necessary. The significance level was 0.05%. RESULTS: HR increased in both groups at the end of the exercise (p=0.00), with no difference between them (p=0.97); SpO2, dyspnea and MAP did not change from rest to the end of exercise (p=0.49; p=0.78 and p=0.25, respectively); The fatigue in the upper limbs increased in both groups (p=0.04), without difference between groups (p=0.79); There was no event of loss of radial artery catheter or steel wire fractures in the sternum. CONCLUSION: The adoption of the cycle ergometer for upper limbs was safe in the 1stPO of HS, even in the individuals using VADs. There was no relationship between the use of the upper limbs cycle ergometer and losses of arterial catheters or steel wire fractures in the sternum.

Efficacy of preoperative amino acid supplements on postoperative physical function and complications in open heart surgery patients: A study protocol for a randomized controlled trial

BackgroundElderly patients undergoing cardiac surgery often show poor nutritional status, muscle wasting, and sarcopenia, which are reported to affect postoperative functional recovery and incidence of complications. Amino acids are essential in maintaining nutritional status, synthesizing muscle protein, and promoting beneficial energy balance of the heart muscle. β-Hydroxy β-methylbutyric acid (HMB) is a leucine metabolite known to increase muscle protein synthesis and inhibit protein catabolism; it has been used to more effectively support patients with muscle wasting due to wearing diseases. However, the efficacy of amino acid administration comprising HMB in patients undergoing open heart surgery remains unclear. This study aims to examine whether preoperative short-term aggressive amino acid administration helps support postoperative recovery of physical function and prevent complications. MethodsThis is a single-center prospective randomized controlled trial (UMIN000030490). Patients aged ≥65 years who will be hospitalized for medical examination before cardiac surgery will be recruited. The participants will be randomly assigned to the experimental or control group. The experimental group will be administered with an amino acid supplement with HMB 1200mg, l-glutamine 7000mg, and l-arginine 7000mg once or twice per day depending on the degree of renal dysfunction, for 14–28 days preoperatively. The control group will not receive any nutritional intervention. The main outcome will be a change in the 6-min walking test distance pre- and postoperatively as a sign of functional recovery. Secondary outcomes such as the incidence of complications; physical, nutritional, and psychological states; mortality; and length of hospital stay will also be evaluated. ConclusionThis clinical study will determine the effects of preoperative short-term oral amino acid supplementation with HMB, l-glutamine, and l-arginine on postoperative physical function in elderly patients undergoing cardiac surgery.

Kidney Injury Molecule 1 (KIM-1) as an Early Predictor for Acute Kidney Injury in Post-Cardiopulmonary Bypass (CPB) in Open Heart Surgery Patients.

Introduction Postoperative acute kidney injury is associated with a higher mortality, a more complicated hospital course with longer hospital stay. Urinary kidney injury molecule 1 may play an important role as an early predictor of acute kidney injury post-cardiopulmonary in open heart surgery. Methods We evaluated 45 patients who underwent open heart surgery from January 2016 to June 2016. Both urinary kidney injury molecule 1 and serum creatinine were evaluated before operation and 3hs and 24hs after operation. Acute kidney injury was diagnosed according to Kidney Disease: Improving Global Outcomes, 2012 guidelines. Results In this study, 27 patients developed acute kidney injury. The three hour-post-surgery urinary kidney injury molecule 1 was significantly higher in the acute kidney injury group (P<0.015) and, at the same time, we did not find any significant difference in the serum creatinine levels between the two groups. Conclusion Although serum creatinine is still the gold standard for diagnosis of acute kidney injury searching for other new markers is mandatory. Urinary kidney injury molecule 1 can be used as simple noninvasive and specific biomarker for early diagnosis of acute kidney injury.

Numerical Modeling of Blood Flows in Rotary Pumps for Use in Pediatric Heart Surgery in Patients Undergoing the Fontan Procedure

We present results from the first stage of numerical modeling of implanted rotary blood pumps which can be used in pediatric heart surgery in patients undergoing the Fontan procedure. Two three-dimensional models of pumps − the centrifugal and axial types − were constructed. Head pressure-flow characteristics were obtained for each model and the effects of pump geometry on blood flow at an operating point of 2.5 L/min were evaluated. Stagnation zones were identified by quantitative assessment of the volume of fluid with flow rates of 0-0.1 m/s. The distribution of flow lines was used to identify vortex zones. Numerical modeling of fluid flow in pumps was run in Fluent ANSYS 19.0 computational fluid dynamics software.

Analysis of Risk Factors for Multiantibiotic-Resistant Infections Among Surgical Patients at a Children's Hospital.

Background: To identify the potential risk factors for multiantibiotic-resistant infections and provide sufficient evidence for multiantibiotic resistance prevention and control.Materials and Methods: We conducted a retrospective study of all patients in pediatric orthopedics, pediatric heart surgery, and pediatric general surgery at a level 3, grade A children's hospital from January to December 2016. The clinical laboratory information monitoring system and the medical record system were used to collect patient information regarding age, surgery type, preoperative length of stay, admission season, incision type, preoperative infection, intraoperative blood loss, postoperative use of invasive equipment, duration of catheter drainage, and timepoint of intraoperative prophylactic antibiotics administration. We used logistic univariate and multivariate regression analysis to analyze the potential risk factors for multiantibiotic-resistant infections among pediatric surgical patients. SPSS 21.0 and Excel software packages were used for the statistical analysis.Results: In total, 2,973 patients met the inclusion criteria: 1,247 patients in pediatric orthopedics, 1,089 patients in pediatric heart surgery, and 637 patients in pediatric general surgery. At the end of the study, 113 patients were multiantibiotic-resistant infection cases; the rate of multiantibiotic-resistant infections was 3.80%, and the detection rate was 84.79%. Multivariate analysis indicated that the multiantibiotic-resistant infection cases were influenced by age, department, admission season, incision type, preoperative infection, and duration of catheter drainage.Conclusions: Age, department, admission season, incision type, preoperative infection, and duration of catheter drainage may provide possible evidence for prevention and control strategies of multiantibiotic-resistant infections.

The Model Theory Approach “Care, Core, Cure” for Patients with Cardiovascular Disease

&#x0D; &#x0D; &#x0D; The impact of cardiovascular disease was felt by individuals and global. By individual approach, prevention and supervision are needed to reduce the burden. Nurses have an essential role in giving holistic standards of nursing practice. The purpose of this study is to provide an overview of the case management of patients with cardiovascular disease by using the theoretical approach "care, core, and cure" model theory. The method used is a case study of 30 patients with Cardiovascular Diseases in Harapan Kita Jakarta National Heart Center. Inform consent was obtained, the initial name and code were assigned to all participant. The results are nine acute coronary syndrome patient, four heart failure patient, ten heart surgery patient, and seven arrhythmia patient. The majority of patients were male, an average age more than 41 years old. Most risk factors are caused by hypertension and smoking. In the acute phase, the "care" and "cure" aspects were more prominent than the "core" aspect. In the non-acute phase, patients need rehabilitation and health education, so the more prominent aspects are "care" and "core" than "cure." The aspect "care" provides an overview of risk factors that result in cardiovascular disease. The "core" aspect shows the needed of education and the "cure" aspects indicating the necessity for medical therapy in patients with cardiovascular disease. In the "Care" aspect, independence nursing intervention can be identified and easily evaluated. In the “Core” aspect, the nurse can recognize the patient's needs during the treatment and provided nursing care plans as needed. In the “Cure” aspect, can be increased coordination among health care providers. Nurse need to develop the model of nursing theory approach in providing nursing care for patients with Cardiovascular Diseases, especially patients who have the opportunity to undergo rehabilitation.&#x0D; &#x0D; &#x0D;

Prevalence of Delirium and Risk Factors in Heart Surgery Patients in Intensive Care Unit: A Retrospective study

Prevalence of Delirium and Risk Factors in Heart Surgery Patients in Intensive Care Unit: A Retrospective study

Health-Related Quality of Life for Patients with Cardiovascular Disease after a Coronary Artery Bypass Graft A Systematic Review

CABG can affect health-related quality of life (HRQoL) and it can take a long time to improve. The following question was raised: ‘How long does it take for the HRQoL of patients with a Coronary Artery Bypass Graft (CBAG) to increase?’ The aim was to analyze the recent scientific production of HRQoL in cardiovascular patients with CABG. The PRISMA approach was used and we examined articles from Scopus, EBSCO and ProQuest that were published between 2014 - 2018. We used “health related quality of life”, restricted our search to “coronary artery bypass graft” and used “after” in the title, keywords and abstract connected by the Boolean operator “AND”. SF-36 was used to assess the HRQoL and it increased within six months after CABG. This was influenced by self-control, obesity, age, gender, emotions and personality. Improving the patient’s quality of life is key for the nurses to control so then the heart surgery patients become prosperous and thus reduce their morbidity and mortality. Keywords: health related quality of life; coronary artery bypass graft; cardiovascular disease

Prognostic factors for heart valve surgery outcomes in Dr Sardjito General Hospital Yogyakarta, Indonesia

Heart valve disease is a serious health probem due its significant effect on mortality.Surgical intervention plays an importan roleinthe management of moderate to the severe valvular heart disease. The evaluation of the patientoutcomes has been widely accepted as one of the important steps to improve the quality of patient care.Recognition of post operative complications might significantly affect the patient quality of life.Therefore, the identification of prognostic factors and morbidity of heart surgery patients can provide valuable insights on improving the quality of patient care.This study aimedto investigat the prognostic factors for heart valve surgery outcomes in Dr. Sardjito General Hospital, Yogyakarta, Indonesia. This study was conducted using data ofpatient’s medical records who underwent heart valve surgeryincluded morbidities and their prognostic factors.The data were analyzed using Chi-square test and logistic regression with significance level of 0.05. During 2010 to 2014, 82 patients underwent heart valve surgeries at the hospital. The kidney disorders and heart failure were significantly associated with the patient morbidity (p 0.05). Multivariate analysis showed that the heart failure is the most significant factor of morbidity. The risk of New York Heart Association (NYHA) class 3 patients were 7.18 times compared with NYHA class 2 patients. In conclusion, the heart failure is the most significant factor for the morbidityof heart valve surgery followed by the kidney disorders at the Dr. Sardjito General Hospital.

Effects of lavender oil inhalation on sternotomy related pain intensity in open heart surgery patients in Egypt

Background: Sternotomy related pain is the main patients' frequent complaint after open heart surgery. Because of the deleterious effects of opioids, it is important to use an alternative way to effectively reduce pain including aromatherapy with analgesics. Aim of the study: This study aimed to evaluate the effectiveness of inhaled lavender oil on an intensity of sternotomy related pain and vital signs in patients who underwent open heart surgery. Subjects and Methods: Quasi-experimental research design was conducted on a convenient sample of 90 patients recruited from 9-bed open heart surgery intensive care unit affiliated to Al Manial university hospital and then assigned randomly to study and groups. The study group was exposed to lavender inhalation with morphine. While the control group of patients exposed to morphine only. Two questionnaires were utilized in data collection. The first one included baseline characteristics including demographic and medical data and the second one were as a visual analog scale to determine the pain intensity. Results: Significant statistical difference was found between the study and control group as the study group demonstrated lower pain intensity scores than the control group (at 5 minutes and, half an hour after). Recommendations: Utilize lavender oil inhalation in the early days of open heart surgery to decrease the consumption Lavender inhalation of opoids and analgesics.

Prevention of embolism in patients with atrial fibrillation after resection of left atrium appendage during open heart surgery (pilot study)

Aim. To assess the potential of prevention cardiogenic embolism by resection of left atrium appendage (LAA) during open heart surgery in patients with atrial fibrillation (AFib). Materials and methods. Study design - cohort prospective. Study group consisted of 19 patients with AFib whom during open heart surgery for coronary and/or valvular disease additional radical resection of LAA was made. After removal of the appendage two-layer linear suture to left atrium was performed without leaving a stump. Control group consisted of 20 patients with AFib, in whom during open heart surgery LAA remained intact. Long-term results were studied using CROQ telephone questionnaire. Results. There was no hospital mortality in both groups. Long-term results in control group were followed up to 6 years, in study group up to 2 years. Radical resection of LAA in patients with AFib reduced the risk of thromboembolic events in long-term period. In control group there were 4 strokes (2 of them were fatal), but no strokes in study group (p &lt; 0,05). Conclusion. Radical resection of LAA in patients with AFib during open heart surgery for coronary and/or valvular disease prevents cardiogenic arterial embolism. (For citation: Sotnikov AV, Melnikov MV, Marinin VA, et al. Prevention of embolism in patients with atrial fibrillation after resection of left atrium appendage during open heart surgery (pilot study). Herald of North-Western State Medical University named after I.I. Mechnikov. 2018;10(2):52-57. doi: 10.17816/mechnikov201810252-57).