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Biomedical subjects

J Kubícek

Publications and source records attributed to J Kubícek.

At least 19 recordsLinked to original sources

Changes in metabolism and blood flow in peripheral tissue (skeletal muscle) during cardiac surgery with cardiopulmonary bypass: the biochemical microdialysis study.

The aim of this study was to monitor the metabolism and blood flow in the interstitium of the skeletal muscle during cardiac surgery with cardiopulmonary bypass (CPB) and in the early postoperative period by means of microdialysis and to compare metabolic changes during CPB at normothermia (NT) and hypothermia (HT). Surgical revascularization using CPB was performed in 50 patients, 25 patients (group HT) were operated using hypothermic CPB, 25 (group NT) using normothermic CPB. Interstitial microdialysis was performed by two CMA 60 probes (CMA Microdialysis AB, Solna, Sweden) inserted into the patient's deltoid muscle. Constituents analysed in the obtained dialysates, collected at intervals, were glucose, urea, glycerol and lactate. Tissue blood flow was monitored by dynamic microdialysis with gentamicin as a marker. In both groups, NT versus HT, similar dynamics of concentrations were found. Low initial concentrations were followed by gradual increases during CPB and in the following phase of the operation. Concentrations were higher in the NT group. Immediately after the operation, the decrease in values continued, with a gradual increase in the succeeding postoperative period in both groups. Similar dynamic changes in the lactate concentration were found in both groups. The gentamicin concentrations were lower in the NT group (versus the HT group). The results showed dynamic changes in the interstitial concentrations of glucose, urea, glycerol and lactate, which depend on the phase of the surgery in the CPB and early postoperative phase in the both groups of patients. Higher tissue perfusion of the skeletal muscle was noted in those patients operated on in normothermia. The dynamics of the concentration changes of these substances in the interstitium of the skeletal muscle has been proven to be caused by both the metabolic activity of the tissue and by the blood flow through the interstitium of the muscle.

Aged↗

[Interstitial microdialysis study of changes in metabolism and blood flow in skeletal muscles during cardiac surgery with normothermic and hypothermic extracorporeal circulation].

AIM: Hypoperfusion of peripheral tissues and splanchnic organs during cardiac surgery in extracorporeal circulation may lead to the origin of serious complications. The aim of the study was to monitor metabolism and blood pressure in interstital peripheral tissue, skeletal muscle, during the operation on the patient with extracorporeal circulation (ECC) in an early post-operation period by means of microdialysis. METHODS: The interstitial microdialysis is a minimally invasive method for the biochemical monitoring of metabolic changes and blood pressure in extracellular space of tissue. The substances in interstitium pass across a semipermeable membrane of the inserted microdialysis probe and may be analyzed. Microdialysis in this study was performed by means of two microdialysis probes CMA (CMA Microdialysis AB, Sweden) inserted into the deltoid muscle of the surgically treated patient. The probes were perfused by the Ringer solution at the rate of 0.3 ml/hour. The dialysates were sampled in the following intervals: beginning of the operation, beginning of ECC, end of ECC, end of the operation, two hours during the post-operation period. Standard biochemical methods were to evaluate, in the dialysates, glucose, urea, glycerol and lactate. The blood flow in the interstitium was monitored by means of dynamic microdialysis of gentamycine as a marker. Microdialysis was performed in 40 patients with ischemic heart disease, operated on in the extracorporeal circulation. In 20 patients the ECC was performed in normothermia (NT), while in the other 20 patients it was made in hypothermia (HT). RESULTS: In both groups, NT versus HT, a similar dynamism of interstitial concentration of the observed substances in relation to the operation phase and in early post-operation period. Low initial concentrations were gradually increasing during the extracorporeal circulation and increased further after the end of extracorporeal circulation and also in the subsequent phase of the operation. The concentration values of the analytes under observation were higher in the groups operated on under normothermia, apparently due to normal cellular activity during normothermia (versus values in hypothermia). Immediately after the operation the observed values decreased in the both groups and subsequently gradually increased in the post-operation period in the both groups. The trend of dynamic changes of the observed analytes, selected as compounds indicating metabolic activity of skeletal muscles during hypothermia documents a lower metabolic activity of the cells during hypothermia and its marked increase (against NT) in the phase of subsequent normalization of the tissue temperature. Analysis of the concentrations of lactate, as a compounds mapping anaerobic metabolism of skeletal muscle, revealed similar dynamic changes in the both groups (NT vs. HT). There were no significant differences, related to the phase of the operation or the phase of immediate post-operation course when the both groups were compared. The analysis of gentamycine concentrations as a flow marker revealed lower gentamycine concentrations in dialysate during the operation, ECC and the early post-operation course in the group operated on in normotheramia (vs. HT), indicating a higher tissue flow in skeletal muscle against the group of patients operated on under hypothermia. CONCLUSION: The results of the microdialysis study demonstrated dynamic changes in interstitial concentrations of the observed compounds (glucose, urea, glycerol and lactate) related to the phase of operation on the heart in extracorporeal circulation and in early post-operation period. A higher perfusion of skeletal muscle was documented in patients operated on under normothermia. It became obvious that the dynamism in the changes of the compounds observed in the interstitium of skeletal muscle was determined by metabolic activity of the tissue as well as by blood flow in the muscle interstitium.

Aged↗

[Surgical myocardial revascularization in a female patient with bilateral occlusion of the common carotid arteries].

Concurrent stenosis of the coronary and carotid circulation is one of the most serious disease. The authors describe the case of a 74-year old female patient with ischaemic heart disease with concurrent bilateral occlusion of the common carotid arteries. Surgical revascularization of the myocardium was made using extracorporeal circulation under general normothermia with protection of the heart muscle from ischaemia by the method of warm blood cardioplegia. In the discussion the authors analyze contemporary possibilities of surgical treatment of ischaemic disease (MIDCAB, OPCAB, operations with extracorporeal circulation) and emphasize the advantages and risks of different procedures.

Aged↗

Changes of the serum antibiotic levels during open heart surgery (ceftazidim, ciprofloxacin, clindamycin).

BACKGROUND: Wound, mediastinal and intracardiac infections are still very serious complications of open-heart surgery. The incidence of it is still in the range of 0.4%-5%. The aims of our study were to assess the adequacy of regimen using ceftazidim (CTZ), ciprofloxacin (CPF) and clindamycin (CLIN) as prophylactic antibiotics and to verify whether cardiopulmonary bypass (CPB) can modify the time of antibiotic serum concentrations. That is why the serum levels of them were measured during open heart procedures. METHODS: The prospective study comprised 75 consequent coronary patients randomized in to three groups receiving 1 g of CTZ or 400 mg of CPF or 900 mg of CLIN i.v. with anesthesia induction. Routine coronary surgery with left internal mammary artery harvesting, moderate body hypothermic (30 degrees C) CPB with crystaloid cardioplegia was performed. Serum antibiotic levels were determined before application, with skin incision, prior CPB induction, after cardioplegia infusion, every 20 minutes of CPB, prior end of CPB, in time of chest closure. Conventional cylinder-plate microbiological assay was used for antibiotic level measurement. RESULTS: All serum antibiotic concentrations showed a sharp decrease immediately after starting CPB and lasted until CPB ended. After initiating of CPB after cardioplegia administration serum concentrations of CTZ (105 min after initial dose) decreased by, on average 55%, CPF (97 min) by 42% and CLIN (116 min) by 78%. CONCLUSION: CPB can modify the time course of antibiotic serum concentrations. The serum levels of CTZ at the end of the longest procedures were found to be below the MICs for some of the suspected pathogens. We recommend to use higher antibiotic doses for prophylaxis and to administer the second dose with protamin sulphate to obtain maximum concentration in newly formed blood clots.

Anti-Bacterial Agents↗

[Kinetics of ceftazidime in prophylactic administration during cardiopulmonary bypass].

Serum ceftazidime levels were followed in 21 patients in which routine coronary bypass surgery with cardiopulmonary bypass was performed. Each patient received one gram of ceftazidime intravenously with anesthesia induction. Antibiotic concentrations were estimated using the microbiologic assay diffusion plate method. The average operation time was 220 +/- 41 minutes (range 130-310). The start of cardiopulmonary bypass was 86 +/- 21 minutes and the full flow time was 104 +/- 21 minutes after starting of ceftazidime application. It can be stated that the decline of ceftazidime serum levels after starting of cardiopulmonary bypass was faster in comparison with standard serum curves of this antibiotic. The concentrations of ceftazidime at the end of some operations were under the supposed minimal inhibitory concentrations for some microorganisms possibly implicated. No infection was recorded.

Cardiopulmonary Bypass↗

[The post-perfusion syndrome after operations performed with extracorporeal circulation].

Postperfusion syndrome (PPS) is a dreaded complication of cardiac surgery operation in extracorporeal circulation (ECC). Four factors play a key role in its pathophysiology: 1. contact of blood with the material of ECC, 2. release of activated leucocytes from pulmonary bed after the release of aortic cross-clamp, 3. translocation of endotoxin due to gut ischemia and its consequent reperfusion, 4. activation of coagulation, fibrinolytic, kallikrein-kinin and complement systems. The occurrence of PPS can be limited by reducing the ECC time and/or cross-clamp time, by using membrane oxygenator in the system of ECC, by using polyester or polypropylene in the set of ECC, by using heparin-coated set or leucocyte filter in the system of ECC, by application of pharmacological dosis of corticosteroids prior to the ECC, by early enteral nutrition. In eligible patients it is possible to eliminate the risk of PPS completely by using the operation without ECC. The experience of the authors with above mentioned problems is given and confronted with literature.

Cardiac Surgical Procedures↗

How long can the previously assembled cardiopulmonary bypass circuit stay sterile?

The sterility of previously assembled cardiopulmonary bypass circuits was investigated for 100 extracorporeal circuits. The closed circuits were assembled using aseptic technique and remained in the pump room until time of use. The mean time from point of setup to point of priming for the 100 consecutive circuits was 32 hours, with a range of 19 to 89 hours. Circuits were primed with the calculated volume of priming solution, circulated for 5 minutes and tested for microbial contamination by withdrawing 20 ml of the priming solution and 10 days incubated in Thioglycolate and Sabouraud culture mediums. All were found to be free of microbial contamination. The results of this investigation demonstrate that the sterility of the extracorporeal circuit, pre-assembled in advance of actual priming, can be maintained over an extended interval when standard aseptic technique is used. This allows the utilization of a pre-assembled circuit for emergency cardiopulmonary support.

Cardiopulmonary Bypass↗

[Personal experience with management of extracorporeal circulation in patients with asymptomatic carotid arteriosclerosis].

The authors describe in following paper their own group of patients with asymptomatic but hemodynamically significant carotid disease operated under cardiopulmonary bypass on. Current studies recommend the "alpha-stat" regime as the optimal strategy of CPB conduction to ensure intraoperative cerebral protection. This study was done to verify this idea. 284 consecutive patients admitted for elective coronary surgery underwent a non-invasive Doppler scanning of extracranial carotid arteries. Twenty seven patients (10%) had significant carotid disease. All patients underwent coronary surgery as the first procedure. There was no cerebral complication in this group of patients and neurological status of these patients postoperatively was the same as it was preoperatively. This study shows that CPB in patients with hemodynamically significant carotid disease can be achieved without impairment of central nervous system with "alpha-stat" regime of perfusion.

Adult↗

[Evaluation of statistical tables in surgery using a computer].

The authors describe the possibility to use a computer in surgery for evaluation of classification tables of child injuries and the six-month report on the activity of policlinical and in-patient surgical departments. The solution of the problem was elaborated using system DOS-RV on a SM 4/20 computer.

Child↗

Pyrophosphate scintigraphy and other non-invasive methods in the detection of cardiac involvement in some systemic connective tissue diseases.

Thirteen patients with systemic lupus erythematosus, 8 patients with polymyositis, and 6 patients with spondylitis ankylopoetica (Bechterew's disease) underwent clinical cardiologic examination and scintigraphy of the myocardium (99mTc-pyrophosphate), ECG, echocardiography, polygraphy, and their blood pressure was taken. The aim of the study was to ascertain how such a combination of non-invasive examinations can help in recognizing a cardiac involvement. In systemic lupus erythematosus cases one or more positive findings were revealed in 9 patients (69%), in 4 patients all examinations were negative (31%). Four patients (50%) with polymyositis had positive findings. In patients with spondylitis ankylopoetica positive findings occurred in 2 cases (33%). The study has shown that a combination of non-invasive cardiologic methods increases the probability of detecting cardiac involvement in systemic connective tissue diseases.

Cardiomyopathies↗

Scintigraphic detection of experimental myocardial infarction with 99mTc-heparin in the dog.

Experimental infarctions were produced in 12 dogs by ligation of the Ramus interventricularis anterior of the left coronary artery, and their uptake of 99mTc-heparin was measured 7, 24 and 48 h as well as 7 days thereafter by recording an in vivo chest scintigram 4 h after intravenous injection of the compound. The dogs were subsequently killed, the heart removed and an in vitro scintigram obtained. Finally, the uptake of the compound was measured in tissue samples. The results indicate that 99mTc-heparin is accumulated in lesions which are not older than 24 h. At the other points in time uptake is low but even 24-h old lesions cannot be demonstrated reliably. The results are impaired by the high blood activity on the cardiac chambers and by the background activity of the lungs. In general, 99mTc-heparin has less useful properties than the more frequently employed 99mTc-pyrophosphate so that a change of procedure is not to be recommended.

Animals↗