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Biomedical subjects

G V Babalian

Publications and source records attributed to G V Babalian.

36 records · Page 2Linked to original sources

[Anesthesia in surgical treatment of the ascending aorta-arch aneurysms].

The paper analyzes anesthesiological maintenance of infusion therapy, optimal criteria for effective brain protection, complications and mortality in 42 patients during operations on the ascending portion and arch of the aorta under deep hypothermic circulatory arrest. For this purpose, the patients were divided into 2 groups: Group 1 comprised 20 patients operated on before 1998; Group 2 included 22 patients operated on in 1998 to 2001. In both groups, circulatory arrest lasted 44 +/- 7 min. The patients were cooled to a temperature of 13.5 +/- 0.5 degrees C, to 15 +/- 0.6 degrees C in the nasopharynx. The duration of cooling was 58 +/- 5 and 73 +/- 6 min, respectively; that of warming-up was 70 +/- 8 and 83 +/- 6 min. Investigations have indicated that determination of the optimum brain cooling requires a complex assessment of central temperature values, electroencephalographic monitoring (visual estimation of a curve and quantitative characteristics), SjbO2 and cerebral metabolism. The investigations have shown that the procedure for anesthesiological maintenance and cerebral metabolism is safe and effective even in patients with arrested circulation lasting longer than 60 min. The operative mortality does not depend on the use of circulatory arrest under deep hypothermia and on its duration. Hemodynamic instability due to bleeding, as well as myocardial infarction, marked hemodilution during extracorporeal circulation are major factors that cause an increase in the rates of incidence of complications and mortality. The procedure used for anesthesiological maintenance and infusion therapy, decreased blood loss, and a reduction in the incidence of myocardial infarction could significantly reduce operative mortality. The fact that there were no neurological complications even during prolonged (80-min) circulatory arrest has shown that the brain-protective procedure including both general and regional cooling is reliable and to the extent of the indicated criteria. So is pharmacological protection.

Adolescent↗

[Temperature regimen of extracorporeal circulation during aortocoronary bypass surgery].

The purpose of the study is to comparatively evaluate the impact of normo- and hypothermic perfusion on acid-base balance (ABB), gas blood composition, metabolic parameters, and hemostasis. Fifty patients undergone multiple aortocoronary bypass under extracorporeal circulation (EC) were examined. Twenty four patients and 26 (Groups 1 and 2, respectively) had been operated on under normo- and hypothermia. The groups did not differ in age, body weight, the duration of an operation, the number of shunts, the time of EC, and myocardial ischemia. ABB, gas blood composition, the concentrations of hemoglobin, lactate, fibrinogen, prothrombin time, thrombin time, activated partial thromboplastin time, activated coagulation time, blood coagulation time as described by Leigh-White, the count of platelets, and ADP-induced platelet aggregation in the early postperfusion and postoperative periods, following 24 and 48 hours after surgery. There were no significant differences in the values of ABB, gas blood composition, blood lactate levels in patients from both groups. However, metabolic acidosis, elevated blood lactate concentrations were more frequently encountered in Group 2 patients, which suggests that hypothermia prduces a more aggressive effect on systemic homeostasis. Impact of normo- and hypothermia on the coagulative link of homeostasis was not revealed. Nevertheless, hypothermic EC halved the functional activity of platelets, which has a substantial effect on the size of postoperative blood loss.

Acidosis↗

[Oxygen transport in patients with ischemic heart disease operated on under a program to preserve the patient's blood].

The results of the studies performed in 112 patients operated on with preservation of the patient's blood are reviewed. This meant pre- and intraoperative blood taking, surgery under normovolemic hemodilution, blood taking and transfusion upon its neutralization with heparin, collection of the blood flowing from drainages. Acid-base balance, pO2, blood Hb level, the degree of Hb saturation with O2, free plasma Hb, platelet count, the level of 2,3-diphosphoglyceric acid have been determined and parameters of oxyhemoglobin dissociation curve have been calculated. Computer monitoring of O2 transport was performed before and after assisted circulation in 28 patients. During surgery it proved possible to collect and return to the patients 10% of the circulating blood. The blood collected during surgery had no negative effect on the hemostasis. The above technique makes it possible to reduce the amount of donor blood used during surgery and has no negative effect on O2 transport.

Adult↗

[Effect of intravenous hypnotics on autonomic response in patients with ischemic heart disease].

The purpose of the case study was to investigate the effect from the bolus dosing of midazolam and ketamine on the autonomic hemostasis in patients with ischemic heart disease (IHD) with the prevalence of the activity of sympathetic or parasympathetic parts in the autonomic nervous system. The IHD patients (n = 75) were examined, after scheduled preoperative therapy, active orthostatic tests and tests of cardiac rate variability (CRV to determinine a type of autonomic response. After orthostatic-test results were analyzed, patients with sympathicotonic (n = 15) and vagotonic (n = 15) types of vegetative response were selected. After midazolam at 0.08-0.12 mg/kg and ketamine at 0.5-1.3 mg/kg were administered, CRV was analyzed in the operating theater.

Autonomic Nervous System↗

[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.

Adolescent↗

[Anesthesiological provision of surgical correction of dilated cardiomyopathy in patients with chronic heart failure].

When dilated cardiomyopathy (DCM) is surgically corrected, intraoperative intracardiac hemodynamic changes and additional ischemia of the disabling myocardium make special demands for anesthesia, prevention of cardiovascular insufficiency, and maintenance of circulatory oxygen-transporting function (COTF). For the development and evaluation of an anesthetic support protocol for patients with DCM, clinical parameters, hemodynamics and oxygen transport was comprehensively analyzed in 50 DCM patients aged 16-68 years in the intraoperative period of surgical correction of myocardial pathology. All the patients underwent implantation of an extracardiac mesh framework in combination, if required, with correction of mitral insufficiency under extracorporeal circulation (EC), drug-induced cold cardioplegia. Analysis of comprehensive clinical studies made it possible to provide scientific evidence and to successfully use the anesthetic support protocol for correcting operations of chronic heart failure in patients with DCM, the basic principles of the support being an effective preoperative preparation of a patient to attenuate the signs of congestive heart failure; preventive intraaortic balloon contrapulsation before surgery; overall monitoring of hemodynamics and oxygen transport; balanced use of anesthetic agents in the doses that exert no cardiosuppressive effect; preload optimization and postload reduction; the minimum use of catecholamines; prevention of arrhythmias; and a reduction in the duration of myocardial ischemia.

Adolescent↗

[The role of hyperoxidation in changes of lipid peroxidation and tissue metabolism in patients undergoing surgery with artificial circulation].

53 patients with various heart diseases subject to cardiopulmonary bypass surgery have been examined. To assess the state of tissue metabolism indexes of arterial and mixed venous blood oxygen balance, lactate concentration, the activity of energy-dependent lymphocyte enzymes and indexes of free-radical plasma processes have been studied. It has been shown that cardiopulmonary bypass in conditions of marked normobaric hyperoxidation (PaO2 more than 300 mm Hg) is accompanied by tissue metabolism intensification and disturbance. Inability of protective antioxidant mechanisms to react to the intensity of free-radical formation due probably both to surgical stress and cardiopulmonary bypass procedure performed in hypothermia leads to negative hyperoxidation effect on metabolism even in conditions of adequate perfusion. A relatively high dependence of the frequency of myocardial depression on the degree of hyperoxidation suggests that myocardial reperfusion by blood with high PaO2 upon anoxic arrest is advisable in hypothermic cardiopulmonary bypass with attenuated activity of the antioxidant systems protecting cells from oxygen free radicals.

Adult↗

[Initial experience of work on a program of complete preservation of the patient's blood in heart surgery].

A complex program on complete preservation of a patient's blood was adopted during and after cardiac surgery with extracorporeal circulation. The major principles of such a "hemotransfusionless" surgery are 1) to minimize irrevocable blood loss; 2) to fully return a cardioplegic solution into the blood during extracorporeal circulation; 3) to apply autohemotransfusion controlled by hemodilution and hemoconcentration; and 4) to reinfuse drained blood in the nearest postoperative period. One hundred and twelve patients were treated by the program. The average expenditure of donor blood per patient was 543 +/- 343 ml, donor blood was not transfused to 44 (39%) patients during their entire stay in hospital.

Blood Preservation↗

[Use of combined lidocaine and bupivacaine spinal-epidural anesthesia in vascular surgery of lower limbs].

The efficacy of combined spinal epidural anesthesia (CSEA) for femoral to distal artery bypass surgery is assessed. Thirty-eight patients were divided into 3 groups. CSE block was performed at L3-L4 (26G pensil-point spinal needle and 18G catheter). In group I (n = 14) blocking was induced with 20 mg of 1% lidocaine and maintained with 2% lidocaine through an epidural catheter. Group II (n = 15) received spinal plain 20 mg of 0.5% bupivacaine. In group III (n = 9) the initial dose of plain 0.5% bupivacaine was 3 ml (15 mg); 5 min after the first bolus the incremental dose of plain bupivacaine 3 ml (15 mg) was injected and spinal needle was withdrawn. Epidural 0.5% bupivacaine was injected as needed. Sensory blockade was assessed by the pinprick test. Two patients in group I (18.2%) were in need of general anesthesia (GA) (inadequate dissemination of solution in 1 case and catheter kinking in the other). In group II GA had to be performed in 1 case because surgery was longer than planned. In group III anesthesia was effective in all cases. The mean level of sensory block in group I was T11.2 +/- 0.4, in group II T9.4 +/- 0.5, and in group III T8.6 +/- 0.55 (p > 0.05). The mean dose of bupivacaine per segment in groups II and III was 1.47 +/- 0.08 and 2.08 +/- 0.01, respectively (p < 0.05), use of epidural catheter during surgery 40 and 11%, respectively (p < 0.05). Arterial pressure drop was 10.8, 14.1, and 11.6% in groups I, II, and III, respectively. The mean total dose was 735 +/- 89 mg (172 +/- 14 mg/h) in the lidocaine group, in group II 38.5 +/- 6.4 mg (10.25 +/- 1.15 mg/h), and in group III 32.8 +/- 2.8 mg (7.46 +/- 1.67 mg/h) (p < 0.05). No neurological problems or PDPH were observed in any of the patients and no vasoactive drugs were needed. CSEA is fit for anesthesia for peripheral vascular surgery. CSEA with double spinal injection is preferable, for it provides a longer anesthesia and hemodynamic stability.

Adult↗