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Biomedical subjects

G F Karliczek

Publications and source records attributed to G F Karliczek.

At least 37 records · Page 2Linked to original sources
PubMed1987

Carola, a computer system for automatic documentation in anesthesia.

A computer system has been designed for documentation and data acquisition during open heart surgery. This computer system (called 'Carola') processes all patient data during cardiac surgery. More than 50 analogue or digital signals are scanned. These are derived from a monitoring rack, a Siemens Servo 900B ventilator with its accessory devices and a heart lung machine. All these values are plotted as well as offline data, such as medications, fluids, laboratory results and user comments, on an A3 format anesthetic record using an eight pen flat bed plotter. Simultaneously all data is written onto a cassette tape. These tapes are then transferred to a database for storage and statistical processing. The sampling frequency is every 10 seconds, averages being calculated over one minute periods. The chart is updated once a minute normally or every 15 minutes for slowly changing signals e.g. temperatures. Hardware and software of the computer have modular design. The hardware consists of two Motorola 6809 based microprocessor systems. The software is entirely written in Pascal. The user interface is implemented on a menu driven basis. A terminal with a keyboard is used for the communication with the users, namely anesthetic nurses and anesthesiologists. The system was readily accepted by the users. The menu structure proved to be easy to learn and allowed fast entries, even when the users were not previously accustomed to the use of a keyboard. The clear and detailed presentation of the data on the plotted chart helped to detect trends early and facilitated therapeutic decisions. From december 1983 the first prototype was used on a routine basis, followed by a second unit in June 1984 and a third in December 1985. Up to now more than 12.500 anesthetic hours have been recorded. Since then almost 100% of all anesthetics performed in our cardiothoracic unit have been documented by the computers, including all short procedures without invasive monitoring and all emergencies.

Anesthesiology↗
PubMed1986

Clinical comparison between four modern membrane oxygenators: Bentley CM 40/50, COBE CML, Sci Med 3500-2A and Travenol LPM 50.

The devices with flat polypropylene membranes can be primed simpler and faster, than devices with the capillary membranes or with silicone rubber membranes. These two devices also offer more protection against venous air admixture and leaking of bubbles across the membrane. From hematologic standpoint there was no clear advantage of one particular device over another.

Carbon Dioxide↗
PubMed1985

Reduced platelet activation and improved hemostasis after controlled cardiotomy suction during clinical membrane oxygenator perfusions.

Platelet damage and postoperative blood loss are less severe after cardiopulmonary bypass performed with a membrane oxygenator than with a bubble oxygenator. However, this advantage of the membrane oxygenator can be partly negated by the platelet damage caused by cardiotomy suction, which implies the aspiration of air along with suction of blood. In order to reduce platelet damage by cardiotomy suction, we developed an automatic controlled cardiotomy suction system by which the aspiration of air was prevented. We evaluated platelet damage in a group of 28 patients (uncontrolled suction, n = 13; controlled suction, n = 15), and we studied the relationship between increasing volumes of cardiotomy suction and postoperative blood loss in a second group of 80 patients (uncontrolled suction, n = 47; controlled suction, n = 33). All patients underwent a coronary artery bypass operation with a membrane oxygenator. We measured significantly lower beta thromboglobulin concentrations during perfusions of approximately 2 hours and we observed a tendency toward shorter postoperative bleeding times if controlled cardiotomy suction was used. There were no significant differences between uncontrolled and controlled cardiotomy suction in platelet number and adenosine diphosphate-induced platelet aggregation. However, blood loss 18 hours postoperatively was significantly less in the controlled than in the uncontrolled suction group when the total volume of cardiotomy suction exceeded 65 L., which corresponded to perfusion times of over 3 hours. In conclusion, prevention of the aspiration of air along with suction of blood significantly reduced platelet activation and postoperative blood loss, particularly when large volumes of blood were aspirated.

Coronary Artery Bypass↗
PubMed1984

Hematological effects of a new hollow fiber membrane oxygenator: a clinical study.

UNLABELLED: The hemocompatibility of a new hollow fiber membrane oxygenator, BOS- CM40 , was evaluated during and after cardiopulmonary bypass for coronary artery bypass graft operations in 10 patients. Blood cells were well preserved by this oxygenator. In particular, platelet numbers at the end of bypass were significantly higher than at the start of bypass and platelet function remained completely intact during bypass. After protamine hydrochloride administration, platelet function decreased slightly but platelet numbers remained unaltered. After release of the aortic cross-clamp the beta-thromboglobulin concentration sharply increased, which shows the damaging effect of cardiotomy suction. Nevertheless, platelet numbers and function did not decrease significantly during this period. Apparently, platelet number and function can remain unaffected by this damaging procedure, provided they are normal before the start of suction. The average postoperative blood loss was 551 ml, which appears to be less than the blood loss in a previous study in which a membrane oxygenator of the envelope type was used. (J. Thorac . Cardiovasc . Surg . 83 (1983) 108-116). IN CONCLUSION: The BOS- CM40 hollow fiber membrane oxygenator proved to be highly hemocompatible .

Adult↗
PubMed1984

Left ventricle descending aorta valved conduit to relieve congenital aortic stenosis in children.

A valved conduit was inserted between the apex of the left ventricle and the descending aorta in 2 patients, 4 months and 10 years of age, respectively, who had valvular aortic stenosis. The development of both patients has been excellent since operation. At control catheterization (1 and 2 years postoperatively) no pressure gradient was found between the left ventricle and the aorta. In both patients the aortic valve area showed growth to near normal size on echocardiographic study 3 years postoperatively.

Aorta, Thoracic↗
PubMed1983

The effect of prostaglandin E1 in patients undergoing clinical cardiopulmonary bypass.

The effect of prostaglandin E1 (PGE1) on protection of platelets during cardiopulmonary bypass (CPB) was evaluated in 9 patients, who were compared with an identical control group of 10 patients undergoing coronary artery bypass grafting. To evaluate the hemodynamic side-effects, PGE1 (0.05 micrograms/kg/min) was infused prior to CPB, resulting in a 26% drop in mean systemic arterial pressure. With this dose, no inhibition of the adenosine diphosphate-induced aggregation could be measured in the pulmonary artery sample. During CPB, the same infusion dose resulted in a severe drop in systemic arterial pressure below 50 mm Hg in 7 of the 9 patients. In 5 of these patients, volume load and phenylephrine infusion could not compensate for the pressure drop, and PGE1 had to be reduced to 0.02 micrograms/kg/min. Platelet aggregation was reduced significantly in the PGE1-treated group compared with the control group, but not completely inhibited during CPB. However, in the postbypass period no platelet preservation was seen in the PGE1 group. In both groups, platelet number and function were equally low. No differences were measured in blood loss or blood transfusion requirements. Except for hypotension, no side-effects of the PGE1 treatment were seen. It is concluded that the hypotension caused by minimal doses of PGE1 during CPB precluded using higher doses, which might have had a greater effect on platelet inhibition. These hypotensive side-effects should be reduced or eliminated before PGE1 can be expected to have the same protective effect on platelet damage that has been demonstrated in animal experiments.

Alprostadil↗
PubMed1983

Two membrane oxygenators and a bubbler: a clinical comparison.

We compared the hemocompatibility of the Polystan bubble oxygenator and the Travenol TMO and SciMed spiral-coil membrane oxygenators in 43 patients undergoing aortic valve replacement. In a subgroup of 27 patients, we collected hematological data and correlated platelet behavior with hemostasis. We found no differences in blood loss or blood (product) requirements among the groups. Platelet and erythrocyte damage was less in the membrane oxygenator groups than in the bubble oxygenator group. Differences in adenosine diphosphate-induced platelet aggregation were equivalent. Drops in this function concurred with intensified cardiotomy suction and administration of protamine. Leukocytosis after bypass was most marked in the SciMed group. Duration of bypass correlated with blood loss and blood requirements in the operating theater. Platelet counts shortly after bypass correlated negatively with duration of bypass and blood loss in the intensive care unit. Platelet function correlated with none of the factors just mentioned. We conclude that platelets and erythrocytes are preserved better by the membrane oxygenator than by the bubbler. The TMO system causes more erythrocyte damage than the SciMed oxygenator, probably due to TMO's dual-pump system. Clinical evidence for these improvements was not found, and this will be possible only when the other factors responsible for blood damage can be controlled.

Adult↗
PubMed1982

Experiences with the Fontan operation.

Up to December 1980 we performed 21 Fontan operations: 8 for tricuspid atresia and 13 for a functional monoventricle. Although palliative, the operation is currently a good method of treating tricuspid atresia. In our experience, the use of a sufficiently large atriopulmonary valved conduit assures a more satisfactory immediate postoperative hemodynamic result than the atriobulbar non-valved connection (RA-infund. tunnel). Good results can be obtained by a modified Fontan operation in patients with a monoventricle. However, with this malformation, very careful preoperative selection of patients is necessary with special regard to pulmonary vascular resistance. The connection between the right atrium and pulmonary artery was established by a valved conduit in 15 patients; no valve was incorporated in the other 6 patients. The largest prostheses gave the best immediate postoperative hemodynamic results. Two patients with monoventricle were successfully reoperated for persistent right-left shunt. The 13 patients so far followed up for at least a year show definite improvement as compared with their preoperative condition. Late complications from the valved prostheses have not been observed so far.

Adolescent↗
PubMed1982

Is prevention of hypertension after open heart surgery possible by blocking 5HT2-receptors with ketanserin?

Eleven patients undergoing coronary or aortic valve surgery received ketanserin (3 X 10 mg i.v.). When surgery was finished hemodynamic measurements were performed prior to and after cessation of nitrous oxide. The results were compared with those of a control group (n = 30), reported in a previous study. At the end of operation the ketanserin treated patients had significantly lower heart rate (84 +/- 16 vs. 96 +/- 14 min-1; Mean +/- S.D.), lower mean arterial pressure (75 +/- 12 vs. 84 +/- 10 mmHg) and higher skin temperature (31.9 +/- 1.3 vs. 27.7 +/- 2.3 degrees C). However, postoperative hypertension after the withdrawal of nitrous oxide was not prevented: similarly as in the control group blood pressure rose and systemic vascular resistance increased. As the last dose of ketanserin was given 60 minutes before the end of anesthesia it is likely that the effect of ketanserin had already worn off.

Adult↗
PubMed1982

Clinical study of blood trauma during perfusion with membrane and bubble oxygenators.

This clinical study was designed to show differences in hemostasis after perfusion with membrane (MO) or bubble (BO) oxygenators in cardiopulmonary bypass. These differences, however, may be obscured by other damaging factors, such as cardiotomy suction, various perfusion durations, or different types of operations. Therefore, only patients undergoing coronary artery bypass grafting were studied. During such operations, rather equal perfusion durations can be expected and mainly apex vent suction is used. Data on postoperative blood loss and transfusions were collected from two groups: one comprising 49 patients perfused with the Travenol TMO membrane oxygenator (MO group) and the other composed of 25 patients with the Polystan VT 5000 bubble oxygenator (BO group). In 10 patients of each group, blood samples were taken at frequent intervals for blood cell counts, for the determination of platelet function, hematocrit, hemoglobin, and plasma hemoglobin, for several coagulation tests, and for the assessment of kidney and liver function. Significant differences between the two groups were found for postoperative blood loss and transfusions, both higher in the BO group. Platelet function was better maintained in the MO group until the moment of releasing the aortic cross-clamp, after which it decreased concurrently with a doubling of the amount of suction. After protamine administration, an additional drop of platelet function occurred and there was virtually no platelet function left in either groups; however, it recovered 90 minutes after bypass, mainly in the MO group. This study shows that hemostasis is better preserved with MO perfusion. Still further improvements may be achieved by preventing the damage of suction and by a correct protamine dose.

Blood Cell Count↗
PubMed1982

Etomidate-analgesic combinations for the induction of anaesthesia in cardiac patients. Part I: Studies in patients with coronary artery disease.

UNLABELLED: In a total of 150 patients undergoing coronary revascularization procedures etomidate was given for the induction of anaesthesia using 12 different dosages and combinations with piritramide, morphine, fentanyl and nitrous oxide. The aim of this study was to establish a method which would result in the smallest possible changes in arterial blood pressure and heart rate during the whole of the induction period, including the stressful phase of endotracheal intubation. In 68 patients cardiac output and pulmonary artery pressure were also measured. RESULTS: 1. In general, more favourable results were obtained when anaesthetic drugs were administered extremely slowly (e.g. by infusion) and according to a standardized dosetime regime. Conversely, the commonly used method - slow incremental injections according to the estimated requirements of the individual patient - led to much greater variations of arterial pressure, especially when fentanyl was combined with etomidate. 2. Combinations of etomidate and morphine led to unsatisfactory results. Dependent on the dose given, hypertension or hypotension were commonly seen. When piritramide was substituted for morphine much more stable haemodynamic conditions were obtained. 3. Surveying our investigations to find the most suitable dose relationship between the hypnotic, etomidate, and the opioid analgesic, piritramide, only small and negligible differences were found: comparing two procedures for the induction of anaesthesia using either high dose piritramide (3 mg . kg-1 given over 10 min), supplemented by low dose etomidate (0.1 mg . kg-1 given over the first 2 min) or an etomidate infusion (50 gamma . kg-1 . min-1) supplemented by a low dose piritramide (0.3 mg . kg-1 given over 1 min) excellent results were found in both groups. 4. In contrast, studies aimed at achieving equally favourable results using the combination of etomidate-fentanyl suggested that the safe dose-range of fentanyl is very narrow: etomidate-infusion (50 gamma . kg-1 . min-1) together with fentanyl 3 gamma . kg-1 led to unacceptable rises in blood pressure and heart rate after intubation, and the larger dose of 6 gamma . kg-1 fentanyl frequently led to hypotension.

Analgesics↗