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Biomedical subjects

R Dudziak

Publications and source records attributed to R Dudziak.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Automated, continuous ST segment analysis in the ECG as a monitor of myocardial ischemia during aortocoronary bypass surgery].

UNLABELLED: Patients with coronary artery disease (CAD) who are subjected to cardiac and major noncardiac surgical procedures have a high incidence of perioperative myocardial ischemia. Earlier studies in patients undergoing coronary artery bypass graft surgery (CABG) indicated the frequency of postoperative myocardial infarction to be directly proportional to the incidence and severity of pre-bypass myocardial ischemia. METHODS: We investigated the incidence of pre-bypass ischemia in 50 patients undergoing elective CABG using an automated ST segment monitoring system (Marquette 7010). Analyzing leads I, II, and V5, this device measures ST segment deviations 60 ms after the J-point. Occurrence of myocardial ischemia was defined as follows: new ST segment deviations larger than 1 mm = 0.1 mV that lasted for more than at least 10 consecutive heartbeats. RESULTS: In 19 out of 50 patients (38%) we found 96 episodes of myocardial ischemia in the pre-bypass period; 47% of all ischemic episodes were associated with significant hemodynamic changes, e.g., tachycardia, hypertension, or hypotension. The incidence of ischemia was different between population sub-groups: patients with a previous infarction had a lower incidence of ischemia (35%) than patients without infarction (44%). Patients with preoperative left ventricular end diastolic pressure (LVEDP) less than 15 mm Hg had a lower incidence of ischemia (29%) than patients with LVEDP greater than 15 mm Hg (50%). Patients treated preoperatively with beta-blockers showed a significantly lower incidence of ischemia (9%) when compared to untreated patients (46%, p less than 0.05). No difference was found between patients with or without unstable angina pectoris or between patients of NYHA classes II, III, or IV. Postoperative myocardial infarction occurred in 2 patients, both with evidence of pre-bypass myocardial ischemia. CONCLUSION: Our study confirms that automated ST segment analysis is able to detect myocardial ischemia similarly to that documented in previous studies using conventional ECG lead analysis.

Aged↗
PubMed1990

[Life-threatening lactic acidosis during total parenteral nutrition. Successful therapy with thiamine].

Two patients, 37 and 44 years old, respectively, developed severe metabolic acidosis after abdominal surgery which was followed by three weeks of total parenteral nutrition. Septicaemia, peritonitis or hypoxia were excluded as possible causes. Both patients had very high serum lactate concentrations (24.3 and 22.8 mmol/l, respectively). Conventional treatment with buffer agents was unsuccessful. Because vitamin B1 deficiency was suspected, two doses of 400 mg thiamine were administered. In both patients the extreme lactic acidosis disappeared immediately after the injections. Both patients were later discharged without any symptoms.

Acidosis, Lactic↗
PubMed1989

Antagonisation of fentanyl-induced respiratory depression by nalbuphine.

The opioid antagonistic efficacy of nalbuphine (20 mg i.v.) was determined in 11 healthy volunteers, who had received 10 micrograms/kg fentanyl ten minutes before. The mean respiratory minute volume decreased to 31.5% of baseline level after fentanyl and increased to 116.8% 2 min. after the administration of nalbuphine. PaCO2, PaO2 and pH values showed the typical clinical signs of respiratory depression and reached pre-fentanyl levels following nalbuphine. No significant hemodynamic changes were caused by the antagonisation. These results suggest that nalbuphine effectively and safely reverses the respiratory depressant effects of commonly used doses of fentanyl without causing hemodynamic side effects.

Adult↗
PubMed1987

[Behavior of the histamine level in induction of anesthesia with propofol and methohexital].

In a study of the effect of intravenous anesthetics on plasma histamine levels, propofol and methohexital were administered to patients. Histamine determination was performed using an improved fluometric method specific for imidazole derivatives. As a primary step, the plasma histamine concentration was determined in 60 healthy, fasting probands and used as a comparative value. The mean value obtained from 60 examinations was 0.38 +/- 0.12 ng/ml, the median value was 0.37 ng/ml (Table 1). The next step consisted in determination of plasma histamine values in 20 patients 1 h following premedication with fentanyl. In this group, the mean value was 0.33 +/- 0.11 ng/ml, the median value 0.316 ng/ml (Table 2). In another 20 patients the plasma histamine concentration was determined 1 h following intramuscular injection of 1.4 microgram fentanyl +0.07 mg/kg droperidol (Thalamonal). In this group, the mean value was 0.373 +/- 0.11 ng/ml and the median value was 0.736 ng/ml. Subsequently, the effect of 2.5 mg/kg propofol (Disoprivan) or 1 mg/kg methohexital (Brevimytal) on plasma histamine levels was examined in a randomized, prospective study in 22 patients of ASA class I and II (Table 3, Fig. 2). Two minutes prior to injection of the test substances and 2, 4, 8, and 13 min following injection, plasma histamine levels, blood pressure, and heart rate were examined. In both groups, no changes in plasma histamine levels were observed during the period of examination. Comparison of the individual time columns within a group as well as intergroup comparisons revealed no statistically significant differences in either the t test or the Wilcoxon-Mann-Whitney U test.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Use of a computer program for statistical calculation of various research data in anesthesia].

A software package for statistical data analysis will be discussed. The program "Test" help also in the computer entry and storage of data. This database package is available for small Personal Computer with a capacity of 512 kB, working with a Disk Operating System (DOS). "Test" is a very simple and very fast working statistical package. The most important advantages of this system are: (1) Simple to work and to learn, (2) Simple data collection and processing, (3) Very fast data analysis and calculation, (4) Checking of test assumptions, (5) Detailed demonstrations of results both with a matrix printer and computer display.

Algorithms↗
PubMed1984

Reversal by nalbuphine of respiratory depression caused by fentanyl.

In 60 ASA class I or II patients given intravenous fentanyl for elective operations in doses large enough to produce postoperative respiratory depression, the intravenous administration of 20 mg nalbuphine resulted in prompt reversal of respiratory depression without loss of analgesia.

Adult↗
PubMed1982

[Advantages and disadvantages of regional anesthesia in comparison with general anesthesia].

The advantages and disadvantages of different anaesthetic techniques are based upon important premises, such as specific effects on the vital functions of the organism, the relationship of these effects to the general condition of the patient, the specific risk of complications due to a particular anaesthetic technique and the decision of the patient. Only with these points in mind can advantages and disadvantages of the different anaesthetic techniques be determined respective to the individual cases. The choice of a suitable anaesthetic technique should depend upon this determination.

Anesthesia, Conduction↗
PubMed1980

The development of haemoglobin preparations for various indications.

The investigational concepts and experimental results of several research groups cooperating on haemoglobin solutions are reviewed over a ten years' period of time. Starting with solutions of stroma-cleared, nearly unaltered human erythrocyte haemoglobin they recognized the disadvantages of a high oxygen affinity, on one hand, and a short intravascular half-life on the other. The former drawback was first compensated by attempts to raise the 2,3-diphospho-glycerate level (Hb-DPG). Later on, better results were achieved by chemical modification of the free haemoglobin with pyrodixal-phospate. This type of pyridoxal-phosphate modified haemoglobin (HbPP) gained particular interest for myocardial perfusion. In order to prolong the intravascular efficiency of preparations to be infused into the central circulation, the pyridoxal-phosphate modified haemoglobin molecules were increased in size by intermolecular cross-linkage (HbHbPP). Possible clinical applications are argued of either type, HbPP and HbHbPP, respectively.

Animals↗
PubMed1979

Sympathoneuronal and sympathoadrenal activation during ketamine anesthesia.

The effects of ketamine anesthesia (3 mg/kg i.v.) on cardiovascular parameters and noradrenaline, adrenaline and dopamine-beta-hydroxylase (DBH) activity in plasma were studied in 12 patients. At 3, 6 and 10 min after induction of anesthesia, a pronounced increase in heart rate (+28%) and in systolic and diastolic blood pressure (+28% and 17% resp.) was observed. Concomitantly noradrenaline and adrenaline concentrations increased significantly from 187 to 415 ng/l and from 97 to 271 ng/l, respectively. DBH-activity in plasma remained almost unchanged. From these results it can be concluded that the well known cardiovascular stimulant effect of ketamine is due to greatly enhanced sympatho-neuronal and sympatho-adrenal activity, presumably brought about by a central mechanism of action of the drug. Furthermore, DBH-activity in plasma appeared not to be a reliable index of sympathetic activity in man.

Adrenal Glands↗
PubMed1979

[The effect of hypothermia and methoxyflurane-anaesthesia on sympatho-neuronal and sympatho-adrenal activity in the course of cardiac surgery (author's transl)].

The concentrations of adrenaline and noradrenaline, and dopamine-beta-hydroxylase in the plasma, and certain haemodynamic parameters, were determined in 14 children undergoing surgical correction of congenital cardiac defects under hypothermia at 30 degrees C and methoxyflurane anaesthesia. During the pre-operative phase of hypothermia at 30 degrees C, the adrenaline levels rose to about 300% of the inital levels, and the noradrenaline levels to about 200%. During the postoperative phase of re-warming at 34 degrees C, a further dysregulative release of catecholamines led to an increase in adrenaline levels to a critical concentration of about 800% of the norm, and in noradrenaline levels of about 400% of the norm. No change was seen in dopamine-beta-hydroxylase activity. Hypothermia thus results in a massive activation of the sympatho-neuronal and sympatho-adrenal systems, which is not prevented by methoxyflurane anaesthesia, and which may endanger the recently operated heart, particularly during the early post-operative period, because of the increased oxygen requirements imposed on the myocardium. In normothermia, on the other hand, methoxyflurane anaesthesia results in only a slight degree of activation of the sympathetic nervous system, which increased only slightly during the post-operative period. Under these conditions, the plasma dopamine-beta-hydroxylase activity remains unchanged. Unlike the changes in plasma catecholamine levels, dopamine-beta-hydroxylase activity cannot be regarded as an index of changes in sympatho-neuronal activity.

Adolescent↗
PubMed1978

[The solutibility of local anaesthetics in cerebrospinal fluid and the dependency of the process on the hydrogene ion concentration (author's transl)].

Reports on in vitro precipitation of local anesthetics suggested the possibility of a damaging effect on nervous tissue with spinal anesthesia. The present assays showed that the solubility of local anesthetics in aqueous media decreases with rising pH-levels. The partial pressure of CO2 determines the pH-level of the cerebrospinal fluid, the level ranging at about 7.35 + 0.011 (95% range: 7.327-7.371). The solubilities calculated for a pH of 7.371 (at 37 degrees C) are as follows: Bupivacaine.HCl 0.83+/-0.10 mh/ml Carticaine.HCl 27 +/-2.8 mg/ml Lidocaine.HCl 24 +/-1.3 mg/ml Mepivacaine.HCl 14.8 +/- 0.2 mg/ml Tetracaine.HCl 1.4 +/- 0.12 mg/ml.

Anesthetics, Local↗