ELECTRICAL IMPEDANCE TOMOGRAPHY OF THE LUNGS IN THE PRACTICE OF THE ANESTHESIOLOGIST.

THE AIM: To assess validity of EITL for mechanical ventilation optimization during GA. MATERIALS: 26 cardiac surgery patients participated in non-randomized comparative study. Everyone was ventilated with protective regimen: Vt - 6-8 ml/kg, breath rate - by normal EtCO2, i/e - 1.1,5. PEEP setting in group A (n = 15) was based on EITL data, in group B (n = 11, controls) - on the discretion of the anesthesiologist. We compared PEEP peak airway pressure (PAP), dynamic compliance, SpO2 and postoperative pulmonary complications. Bronchoscopy (FTBS) was performed after the onset of mechanical ventilation in 15 patients. RESULTS: Mask ventilation contributed redistribution of ventilation to ventral regions in 88,4% ofpatients. Ventilation by the end of surgery was remained un-changed more often in gr A than in gr B (86,6% vs. 36,6%, p = 0,026). PAP was higher in gr B by the end of surgery (19?1,4 vs. 17,3±2,2 cm H20; p = 0,03). Compliance by the end of surgery was not reduced below baseline's more frequently in gr A (73,3% in gr A vs. 27,2% in gr B, p = 0,053). After FTBS, ventilation after of mechanical ventilation renewal was comparable with baseline ' in 80%, deteriorated in 13,3% and improved in 6,6% ofpatients. CONCLUSIONS: 1) EITL is a convenient toolfor ventilation dynamic evaluation during anesthesia; 2) EITL advances the mask ventilation, allows to set up appropriate PEEP during anesthesia and to evaluate safety of the disconnection during FTBS; 3) EITL contributes to professional education of anesthesiologists.

[DIAGNOSTIC AND THERAPEUTIC BRONCHOSCOPY IN PATIENTS UNDERGOING CARDIAC SURGERY IN INTRA- AND POSTOPERATIVE PERIODS].

The article presents research conducted to evaluate the use of diagnostic and therapeutic fiberoptic bronchoscopy in the treatment of ventilator-associated pneumonia (VAP) and tracheobronchitis in patients in cardiac ICU. The paper presents the results of the study and comparison of invasive techniques for sampling from the respiratory tract for bacteriological analysis. We studied the bacterial profile of ICU, original content of the respiratory tract of cardiac patients in the intraoperative period and possible ways for prevention of VAP and tracheobronchitis in the postoperative period using bronchoscopy. In addition data on the effect of bronchoscopy on the respiratory and cardiovascular systems in cardiac surgical patients undergoing mechanical ventilation presented.

[Mesenteric circulation evaluation during myocardial revascularization with different temperature modes of extracorporeal circulation].

The Mesenteric blood circulation during myocardium revasculization was investigated 40 patients were divided in 2 groups: 1st group - normothermia CPB, 2nd group hypothermia CPB. It was found that reduced mesenteric perfusion occurred in both groups, but it was more pronounced in hypothermia CPB group and was caused by a significant deterioration of the microcirculation.

[Tissue oxygenation monitoring during cardiac surgery].

UNLABELLED: The aim of this study was to evaluate tissue oxymetry dynamics in patients with different initial tissue oxygenation levels and to analyze the relation of these data with the perioperative period flow peculiarities. PATIENTS AND METHODS: 92 patients undergoing on-pump myocardium revascularization or valve replacement were included in the study. Regional oxygenation in all patients was monitored with FORE-SIGHT Laser Tissue Oximeter. Sensors were located in the right hemisphere projection and on right forearm. Tissue (StO2) and cerebral (SctO2) oxygenation data were analyzed before anaesthesia start, before CBP on 45th -minute of CPB and in the end of the operation. At these stages also was performed standardized time (3 minutes) vessel occlusion test (VOT). RESULTS: None patients had episodes of StO2, decrease below the critical level during the operation, that allows to talk about central haemodynamics stability during the study. 1st group - patients with initial StO2, below 70% (n=19). In this group StO2, remain low throughout the operation. 2nd group- patients with initial StO2, over 70%, but before CPB decreased below 70% (n=49). 3rd group - patients with high StO2, throughout anaesthesia. VOT data confirmed tissue oxygenation disturbances in Ist and 2nd groups. In st group oxygen reserve (OR) was lower than in other groups and at the end of the surgery - lower than initial one. In 2nd group OR decreased significantly before CPB and during CPB didn't differ from 1st group. In 3rd group OR during anaesthesia was higher, than in 1st and 2nd group, but decreased by the end of the surgery. Lactate level after CPB doesn't exceed the upper limit, however, it's level was higher in the 1st and 2nd group than in the 3rd group. Central vein saturation in 3rd group was higher than in the Ist and 2nd group at all stages, except for operation start. Lower StO2, levels in 1st and 2nd group were accompanied with extension of ALV ICU length-of-stay and hospitalization. RESUME: Tissue oxymetry may be useful for regional oxygenation assessment during anesthesia. There is a decrease in tissue oxygenation and oxygen reserve of peripheral tissues during on-pump cardiosurgery The low tissue oxygenation level during preperfusion period may be a predictor for early postoperative complications.

[Surgical treatment of postinfarctial ruptures of interventricular septum].

21 patients were operated on the reason of postinfarctial ruptures of interventricular septum within 1989-2009 years. The mean age was 61.3 ± 7.8 years. The preoperative diagnostic means were echocardiography and magnetic resonance imaging. All patients were in critical condition, demonstrated postinfarctial left ventriculum remodeling and significant decrease of its functional reserves. Myocardial revascularization together with septal reconstruction, mitral valve and ventricular cavity reconstruction were performed. The analysis of the results proves that the active-expectant treatment tactics leads to the significant decrease of perioperative lethality. The optimal volume of surgical treatment is a liquidation of the interventricular defect together with geomentrical reconstruction of the ventricular cavity, wich is indepentant from the stage of infarction.

[Vascular reactions during cardiac surgery].

Treatment results of 96 patients with ischemic heart disease, operated on with the use of artificial blood circulation and polycomponent anesthesia, were analyzed. The modified protocol of infusion therapy and functional tests (passive limb elevation and volume load test) were used to assess the dynamic vascular reaction among patients of the main group (n=54). Patients from the control group (n=42) received only standard infusion therapy. The use of functional test permits more individual calculation of the necessary volume to correct vascular reactions on the initial anesthesia. The simultaneous monitoring of tissue and brain oxygenation permits adequate assessment and correction of short vascular reactions during the cardiac surgery. During short vascular reactions the tissue perfusion in the absence of cardiac insufficiency changes in an inverse proportion to arterial blood pressure.

[Efficiency and controllability of esmolol (breviblock)-induced adrenergic blockade during the heart and aorta surgery].

This article contains analysis of retrospective and prospective studies of use of selective ultrashort Beta-blocker esmolol during intraoperative period in cardiac surgery patients in recent years. The drug is highly effective and controlled the means for prevention and treatment of tachycardia, arising as a result of the sympathoadrenal system activation during anaesthesia induction (laryngoscopy, trachea intubation) and intraoperative period (during heart and aorta manipulations). It should be considered that the use of esmolol has dose-dependent effect. For the treatment of tachycardia against the background of hypertension is recommended dose of 0.6-1.0 mg/kg, with normal blood pressure it is recommended to decrease the esmolol dose up to 0.3-0.6 mg/kg. It is possible to use esmolol-infusion in the dose of 50-200 g/kg/min prolonging adrenergic blockade during heart and aorta surgery.

[The role of magnesium in the implementation of vascular reactions during anesthesia in cardiac surgery patients].

UNLABELLED: The purpose of the study is to examine the relationship between the concentration of magnesium in plasma and vascular reactions during cardiac surgery. MATERIALS AND METHODS: The study included 77 patients with coronary artery disease who underwent myocardial revascularization surgery. In the first group (n = 44) during the entire operation infusion solution "potassium and magnesium asparginate" (Berlin-Chemie) was carried out at a rate of 1.5-2 ml/kg/h, in the second group (n = 33) patients were injected magnesium free crystalloid solutions. An analysis of central hemodynamics (PiCCO Plus) and microcirculation (laser Doppler flowmetry LASMA) was carried out. CONCLUSION: Maintenance of normal concentrations of magnesium in blood plasma reduces the incidence of episodes of intraoperative hypertension and improves peripheral microcirculation.

[Diagnostics of volemic disorders in cardiosurgical patients: modern state of the problem].

Volemic disorders are widely encountered in anesthesiology and intensive therapy. Lower cardiac output caused by inadequate preload leads to tissue hypoperfusion, increased frequency of perioperative complications and higher death rates. The objective diagnosis of the volemic status remains a challenge since before as all the indices characterizing the preload, which are currently used in clinical practice, enable the true preload to be estimated only to a certain extent. The paper considers the currently available diagnostic studies for volemic disorders in cardiosurgical patients, their merits, demerits, and possible limitations of their use.

[Anesthetic maintenance during myocardial revascularization in patients over 70 years of age].

The authors performed a comparative retrospective analysis of preoperative and intraoperative periods in 50 patients aged 70-83 years with coronary heart disease (CHD). A control group comprised the similar patients aged 40-59 years. The geriatric patients showed a higher incidence of arterial hypertension, respiratory and central nervous system diseases, cardiac arrhythmias, and anemia as an outcome. In CHD patients aged 70-80 years, balanced general anesthesia based on lower-dose midazolam and fentanyl, on subnarcotic-dose ketamine during the metered use of isoflurane and adequate infusion therapy provided reasonable hemodynamic stability during the induction of anesthesia and the preperfiusion period without administering cardiotonic agents. Intraoperatively, there was a more pronounced reduction in pulmonary oxygenizing function, body temperature and more needs for cardiotonic and diuretic therapy and erythrocyte mass after the basic stage of surgery.

[Unintended cooling, active warming, and microcirculation in cardiosurgical patients].

The study was undertaken to compare various methods to maintain a patient's body temperature and to evaluate their impact on microcirculation during myocardial revascularization under normothermal extracorporeal circulation (NTEC). The study enrolled 50 patients with NYHA Functional Classes III-IV coronary heart disease, who underwent aortocoronary bypass surgery under NTEC. A HICO-AQUATHERM 660 water-warming unit (Hirtz, Germany) was used in Group 1 patients (n=30). A Bair Hugger air-warming unit (Arizant, U.S.A.) with a mattress located under a patient was employed in Group 2 (n=20). Intraoperative microcirculation monitoring was carried out by a laser analyzer (Lazma, Moscow).

[Changes in hemodynamics and volemic status during intraoperative blood exfusion in patients with chronic heart failure].

Forty-five patients with dilated cardiomyopathy, NYHA Functional Classes III-IV chronic heart failure with left ventricular ejection fraction 26.98+/-7%, who had undergone surgical left ventricular remodeling using an extracardiac conduit in combination with mitral or tricuspid valve correction and blood exfusion, were examined. Central hemodynamic monitoring was performed, by using a Swan-Ganz catheter in all the patients at surgery. In 11 patients, transpulmonary thermodilution in combination with pulmonary artery catheterization with a Swan-Ganz catheter (PICCO-Plus + VOLEF, Pulsion, Germany) was used in 11 patients to monitor central hemodynamics. Right atrial blood autoexfusion was carried out at a volume of 6-10 ml/kg prior to extracorporeal circulation. At blood sampling, blood pressure (BP), heart rate (HR), central venous pressure (CVP), and pulmonary pressure were in the normal range. There were no significant changes in HR, BP, and CVP after blood exfusion. A significant lowering was noted in systolic and diastolic pulmonary pressure by 20-25%. Under the influence of blood exfusion, there was a reduction in cardiac pump function, which appeared as decreases in stroke index by 24% (p < 0.05) and cardiac index by 18% (p < 0.05). The parameters reflecting left and right ventricular myocardial contractility (functional state index, global ejection fraction, and dPmax) underwent no negative changes. According to the changes in systolic and diastolic BP and total peripheral vascular resistance index, left ventricular postload did not change either. At the same time, global end-diastolic volume index was reduced by 22% (p < 0.05), right cardiac and right ventricular end-diastolic volumes were decreased by 20% (p < 0.05) and 23% (p < 0.05), respectively; the left ventricular end-diastolic volume index tended to be lower. These data suggested that diminished cardiac pump function was caused by a predominant reduction in global preload, as evidenced by volumetric monitoring. At the same time the changes in CVP, BP, and HR did not reflect the altered volemic status. To prevent destabilization of the circulatory system, blood should be sampled just before extracorporeal circulation after aortic cannulation.

[Target-oriented infusion therapy in patients during myocardial revascularization].

The paper analyzes goal-oriented infusion therapy used during myocardial revascularization on the working heart. Forty-seven patients with coronary heart disease were examined. Group 1 (control) (n = 20) received standard infusion therapy (a combination of colloids and crystalloids (1:1) at a rate of 6-7 ml/kg/h, by being oriented to indices, such as heart rate, blood pressure, central venous pressure, and diuresis rate. In group 2, an anesthetist was oriented to central hemodynamic parameters during infusion therapy. In addition, the patients of this group underwent the 45 degrees passive leg raising test. In this group, a volume load was done at the beginning of an operation until the maximum possible SV resulted from increased preload (global end-diastolic volume index). The goal of infusion therapy throughout the operation was to maintain these values of the latter index. Goal-oriented infusion therapy, the purpose of which was to determine and maintain the individual optimal values of preload, was found to minimize hemodynamic disorders at surgery and to reduce the frequency of use of cardiotonic agents and the duration of artificial ventilation.

[Impact of preoperative levosimendan therapy on the volemic status and vascular tone of patients with chronic heart failure during anesthesia].

The impact of preoperative levosimendan therapy on the volemic status and vascular tone was studied in patients with chronic heart failure (CHF) during anesthesia and the ways of correcting the occurring changes were defined. The study included 21 patients with CHF in the presence of dilated cardiomyopathy, who underwent mitral valve replacement and tricuspid valvoplasty. Group 1 patients (n = 11) were given levosimendan (Simdax) in a dose of 0.05-0.1 mg/kg x min 2 days prior to surgery; Group 2 (n = 10) was control. Central hemodynamics was monitored by the transpulmonary thermodilution technique (PiCCO-Plus, Pulsion Medical System). Intraoperative monitoring of microcirculation was made using a laser microcirculation analyzer. It has been established that the preoperative administration of levosimendan causes an increase in stroke index at critical surgical stages. With the use of levosimendan, peripheral microcirculation improves and nutritional blood flow increases. The preoperative use of levosimendan causes a reduction in the tone of resistance vessels during anesthesia, which can require vasopressor support in the postperfusion period; a levosimendan-induced decrease in preload requires infusion correction of relative hypovolemia.

[Intraoperative evaluation of the microcirculatory system in cardiosurgical patients].

The investigation was undertaken to study the specific features of vessels of the microcirculatory bed in cardiosurgical patients during myocardial revascularization. The study covered 20 patients with NYHA Functional Classes III-IV coronary heart disease. Ten patients from Group 1 were operated on the working heart (aortocoronary bypass surgery (ACBS) without extracorporeal circulation (EC)). In 10 patients from Group 2, myocardial revascularization was performed under normothermal (tcenter = 36 degrees C) EC (ACBS + EC). Microcirculatory blood flow was analyzed by laser Doppler fluometry. Microcirculatory blood flow index, variation coefficient, neurogenic and myogenic microvascular tone indices, and bypass value were estimated. It has been concluded that 1) laser Doppler fluometry evaluates the microcirculatory bed during anesthesia in cardiosurgical patients; 2) a dynamic response of the microcirculatory bed to stresses is retained during general anesthesia; 3) under normothermal EC, there are more pronounced microcirculatory disorders than during myocardial revascularization on the working heart.

[Optimization of the volemic status of cardiosurgical patients before initial anesthesia].

Twenty-six patients with coronary heart disease who had undergone aortocoronary bypass surgery were examined. In all the patients, central hemodynamic parameters were monitored by transpulmonary thermodilution. The patients were divided into 2 groups. In Group 1 (n = 14), routine initial anesthesia was made without a preliminary volumetric loading test. In Group 2 (n = 12), a controlled volumetric loading test was carried out before induction; a decision on whether it might be made was taken on the basis of the results of a loading test for passive leg raise. The patients from both groups were hypovolemic at baseline, as suggested by the low values of central venous pressure (CVP) and global end-diastolic volume index (GEDVI). By the initiation of initial anesthesia, in Group 2 the mean blood pressure (BPmean), CVP, stroke index (SI), and GEDVI were significantly higher and total peripheral vascular resistance index (TPVRS) was significantly lower than in Group I (p < 0.05), as achieved via preliminary loading tests. After the maximum hypnotic effect being achieved in Group 1, there were reductions in BPmean, SI, GEDVI, dPmax, and TPVRS (p < 0.05). In Group 1, 50% of the patients were observed to have hypotension episodes requiring the patient to be placed in Trendelenburg's position and to be given colloids as jets, and 3 patients received bolus vasopressors. After achieving the maximum hypnotic effect, BPmean, SI, GEDVI, and dPmax also decreased in Group 2 patients (p < 0.05). However, due to preliminary loading tests, these variables remained to be in the normal ranges and were significantly higher than in Group 1 (p < 0.05). IOPSS objectively reflects the preload status at all stages of initial anesthesia and the leg raising test enables prediction of a cardiovascular response to a volumetric load. When infusion therapy is performed, it is advisable to take into account a relationship between altered preload (GEDVI) and cardiac performance (SI). This volumetric loading testing tactics before induction promotes GEDVI to be maintained in the normal ranges throughout the initial anesthesia and minimizes hemodynamic disorders at this stage.

[Use of a potassium and magnesium asparaginate solution to maintain the balance of potassium and magnesium during cardiosurgical interventions under extracorporeal circulation].

The study included 42 patients with coronary heart disease operated on the coronary arteries. A potassium and magnesium asparaginate (PMA) solution, 450-1000 ml, was injected in 30 patients for 5-7 hours; other crystalloid solutions was used in a control group (n = 12). The concentrations of potassium and magnesium were measured prior to surgery, following initial anesthesia, before and after extracorporeal circulation (EC). The measurements suggested a significant potassium and magnesium intake at surgery under EC. The use of PMA solution showed its advantage in stabilizing the study electrolytes at the main surgical stages. Inclusion of PMA into infusion therapy considerably reduced a need for an additional use of concentrated KCl solution to maintain potassium at the preoperative level. Of particular importance was the use of PMA to maintain magnesium that was held in the upper normal range throughout the operation, as shown by both the median values and an individual analysis. When PLA was not administered, the mean concentration of magnesium was consistent with that in the lower normal electrolyte range and 50% patients developed hypomagnesemia. The comparative analysis of the clinical course after EC in both groups of patients with different levels of magnesium was indicative of the better status of some hemostatic parameters with the level of magnesium being maintained in the upper normal range.

[Clinical and laboratory evaluation of 20% albumin (plasbumin) used in cardiosurgical patients].

A randomized comparative study of the effect of 20% Albumin (Plasbumin) solution and 4% succinylated gelatin (helofusin) solution on homeostasis was conducted in 36 cardiosurgical patients when the solutions were used as components to fill a pump oxygenator (PO). A comparative analysis has indicated that the use of albumin in the primary volume of PO at a concentration of 2-3% provides a higher level of total protein and better maintains colloid osmotic pressure during extracorporeal circulation than that of helofusin. At the end of an operation, the oxygen index was higher in the patients given albumin (Plasbumin). It has been also ascertained that plasbumin is well tolerated, causes no adverse reactions, and produces no dose-dependent effect.