Biomedical subjects

D Kling

Publications and source records attributed to D Kling.

At least 73 records · Page 4Linked to original sources

PubMed1987

Influence of nimodipine and nifedipine on intrapulmonary shunting--a comparison to other vasoactive drugs.

This study was assigned to investigate the influence of calcium channel blockers (nimodipine and nifedipine) in comparison to other vasoactive drugs (nitroglycerin, dopamine) on pulmonary shunting (Qs/Qt). Fifty anesthetised patients scheduled for aortocoronary bypass operation were randomly allocated to 5 groups receiving one of the following drugs: nimodipine 1.0 microgram X kg-1 X min-1; nifedipine 0.7 microgram X kg-1 X min-1; nitroglycerin (TNG) 0.5 microgram X kg-1 X min-1; dopamine; micrograms X kg-1 X min-1; placebo (0.9% NaCl). Nimodipine as well as nifedipine led to a significant increase in cardiac output (+44%; +39%), pulmonary vascular resistance simultaneously decreased (-25%; -28%). PaO2 increased significantly (+16%; +13%), too, whereas Qs/Qt remained almost unchanged. In contrast, the increase in cardiac output induced by dopamine (+27%) was accompanied by a significant increase in shunting (+34%). TNG application did not alter Qs/Qt, but pulmonary artery pressure (PAP) decreased markedly (-19%).

Blood Pressure↗

PubMed1987

Temporal sequence of morphological alterations in artery walls during experimental atherogenesis--occurrence of leukocytes.

In rabbit carotid arteries arteriosclerotic lesions were induced by repeated local transmural electrical stimulations. The sequence of early morphological alterations in the vessel wall and especially the kinetics of leukocytes were examined by transmission electron microscopy. After a stimulation period of only 1 day monocytes and heterophilic granulocytes adhered to the endothelial surface. In the subendothelium mainly beneath the anode, focal amorphous insudates were present together with mononuclear and granulocytic cells. Thereby, the endothelium was maintained as a continuous lining as shown by surface staining with silver nitrate. However, both pattern and size of the endothelial cells were altered in comparison to the controls. Some of the endothelial cells displayed a heavy cytoplasmic silver salt deposition. After 2 days of the electrical stimulation schedule, the first myocytes occurred in the subendothelial space. The mediamyocytes sending pseudopods through the internal elastic lamina still appeared to be in a contractile phenotype. In the 7-day-old proliferative lesion modulated smooth muscle cells were the predominant cell type; only 10%-20% of the subendothelial cells were identified as macrophages and heterophils. This proportion decreased further, and after a stimulation period of 28 days the granulocytes disappeared completely. At this stage of plaque development, the intimal myocyte population mainly consisted of contractile smooth muscle cells and intermediary states between the contractile and modulated phenotype. The insudation, immigration of white blood cells, and subsequent migration and proliferation of myocytes reinforces the view that the initial phases of arteriosclerotic lesions may represent a special form of an inflammatory response.

Animals↗

PubMed1987

Extravascular lung water and hemofiltration during complicated cardiac surgery.

Hemofiltration (HF) is an established method for treating patients with impaired renal function and excessive fluid retention. In cardiac surgery fluid accumulation during extracorporeal circulation (ECC) may contribute to postoperative organ dysfunction, leading to severe pulmonary insufficiency. In this study our experiences with hemofiltration installed in the cardiopulmonary bypass are demonstrated in patients with preoperative pulmonary edema, impaired renal function, and long-term ECC, proving its efficacy by measurement of extravascular lung water (EVLW) in the early post-bypass period. EVLW-measurement was performed using the thermal-dye technique with indocyanine green and a microprocessed lung water computer. Our data demonstrate that hemofiltration during ECC is a valuable method for controlling fluid balance. It facilitates the intra- and postoperative management of patients with end-stage renal failure or with preoperative pulmonary edema. HF seems to be helpful by decreasing the risk of complications such as fluid overload, which is demonstrated by measurement of EVLW.

Blood↗

PubMed1987

Spectral analysis of the EEG during hypothermic cardiopulmonary bypass.

In 39 patients undergoing aorto-coronary-bypass grafting, spectral analysis of the EEG (compressed spectral array: CSA) and calculation of spectral edge frequency (SEF) were performed. The effects of different temperatures and of perfusion pressure (PP) were analyzed. Predictable patterns were observed. During cooling on cardiopulmonary bypass (CPB), linear regression analysis revealed a close correlation between SEF and tympanic membrane (Tty) or nasopharyngeal temperature (Tnp). During rewarming, a nonlinear correlation between SEF and Tty or Tnp was found. Rectal temperature as well as blood temperature in the arterial or venous line of the oxygenator seemed to be less useful. The independence of SEF and PP was demonstrated during the whole procedure. At the onset of CPB, after correction of the aortic clamp for performance of the aortic anastomosis and after removal of the aortic clamp, bilateral EEG slowing of varying duration occurred in 20 patients. Comparison of mean SEF before and after CPB revealed a difference of about 5 Hz. In no patient were major neurological abnormalities observed postoperatively.

Body Temperature↗

PubMed1987

Age and cardiac surgery. Influence on extravascular lung water.

This study was designed in order to evaluate the influence of advanced age on extravascular lung water (EVLW) content. Forty patients undergoing aortocoronary bypass grafting were prospectively divided into two groups according to age below 45 years (group 1; n = 20) and above 65 years (group 2; n = 20). The EVLW was measured using the double indicator dilution technique with indocyanine green as the nondiffusible indicator. Starting from similar baseline values before extracorporeal circulation (ECC), EVLW significantly increased after ECC only in the elderly patients (max + 1.51 ml/kg), whereas lung water content in the other group remained almost unchanged. No significant differences in left ventricular filling pressure (PCP) could be observed. Regression analysis revealed a strong positive correlation between age and increase in EVLW after ECC. Simultaneously, PaO2 was decreased (-114 mm Hg) and intrapulmonary shunt fraction (Qs/Qt) was increased only in this group. Within the next five hours after ECC, lung water returned nearly to baseline values and pulmonary function was normalized. It is concluded that increasing age was associated with a transient increase in EVLW after ECC due to a more pronounced fragility of the pulmonary endothelial membrane or/and to depressed left ventricular performance.

Adult↗

PubMed1987

[Hemodynamic effects of the anti-arrhythmia agent flecainide (Tambocor) in coronary surgery patients].

Flecainide, a new antiarrhythmic drug (group 1 according to the classification after Vaughan Williams), is used in the treatment of atrial and ventricular arrhythmias. Cardiac patients are compromised by arrhythmia during operative procedure. The haemodynamic effects of 1 mg/kg b.w. flecainide compared to a placebo solution were studied randomised in 20 patients undergoing coronary artery surgery (before cannulation of the large vessels). Mean arterial pressure, PAP, PCP, PRA and TPR remained unchanged, whereas heart rate (-12%), cardiac index (-17%) and dp/dtmax (-35%) decreased significantly. Total systemic resistance increased by 14%. The results show that it is possible to use flecainide during coronary artery surgery. In patients with reduced myocardial function it should be injected carefully and a decreased dose is recommended with regard to deterioration of left ventricular contractility.

Arrhythmias, Cardiac↗

PubMed1987

[Comparative hemodynamic study of anesthesia induction with propofol (Diprivan), thiopental, methohexital, etomidate and midazolam in patients with coronary disease].

UNLABELLED: In patients undergoing cardiac surgery, the induction of anesthesia is not without risk because of specific cardiovascular effects of the anesthetic and the preoperative state of the patient. The hemodynamic effects of etomidate, midazolam, thiopental, and methohexital are well known: etomidate is an anesthetic that induces only minor cardiovascular changes; its influence on the endocrine system, however, has reduced its clinical indication. Barbiturates such as thiopental and methohexital produce negative inotropic effects in combination with an increase in heart rate and myocardial oxygen consumption; midazolam reduces pre- and afterload in patients with poor left ventricular function. Propofol, a new short-acting induction agent with good anesthetic properties, is said to diminish arterial pressure as well as myocardial oxygen consumption. METHODS: In a randomized study we investigated the hemodynamic effects of intravenous induction with propofol (2 mg/kg body wt.), thiopental (5 mg/kg), methohexital (1 mg/kg), etomidate (0.3 mg/kg), and midazolam (0.15 mg/kg) in 50 patients undergoing coronary artery bypass grafting. All patients were premedicated with flunitrazepam (0.03 mg/kg up to 2 mg) and morphine hydrochloride (0.2 mg/kg up to 15 mg) 100 min before the investigation. After 0.003 mg/kg fentanyl the patients received the induction agent in the above-mentioned dosage within 40 s followed by 0.1 mg/kg pancuronium bromide. Hemodynamic measurements were performed 1, 3, and 5 min after the end of the injection as well as 1 and 5 min after intubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗

PubMed1987

[Meptazinol, a new analgesic. Hemodynamic and respiratory effects].

In a prospective, randomized double-blind study the hemodynamic and respiratory effects of i.v. meptazinol, a new synthetic narcotic agonist-antagonist analgesic given in 2 dosages (2 mg/kg and 4 mg/kg), were compared over 15 min to a control group that received 0.9% saline solution as placebo. In a total of 80 patients scheduled for elective aortocoronary bypass surgery, the study was performed before and during general anesthesia and during extracorporeal circulation (ECC). A dose-dependent increase in mean arterial pressure (MAP) and total systemic resistance (TSR) were the predominant hemodynamic effects of meptazinol before and during anaesthesia (Tables 1 and 2). Within the study period no change in heart rate (HR) or cardiac index (CI) could be observed. Directly measured left ventricular parameters revealed a significant increase in left ventricular pressure (LVEDP, and dp/dtmax (Fig. 1). During ECC meptazinol injection was followed by a dose-dependent increase in perfusion pressure, indicating a direct vasoconstrictive effect; no influence on the capacitance system ("venous pooling") could be observed (Fig. 2). In the spontaneously breathing, premedicated patients (morphine hydrochloride 0.15 mg/kg and flunitrazepam 0.03 mg/kg) paO2 increased and paCO2 decreased, especially after injection of the higher dosage of meptazinol; there was no influence on intrapulmonary right-to-left shunting (Qs/Qt).(ABSTRACT TRUNCATED AT 250 WORDS)

Azepines↗

PubMed1987

Low-dose fentanyl analgesia modified by calcium channel blockers in cardiac surgery.

The hypothesis that calcium channel blockers can potentiate and prolong the anti-nociceptive effects of opioids was tested. Forty-five men scheduled for aorto-coronary bypass operation received fentanyl according to their individual demands (haemodynamics, clinical parameters). The patients were allocated at random into three groups receiving either nimodipine 1.0 microgram kg-1 min-1 (Group 1, n = 15), nifedipine 0.70 microgram kg-1 min-1 (Group 2, n = 15), or no calcium channel blocker (Group 3, n = 15). Cerebral activity was monitored using a computerized spectral analysing system before and during the operation. The total amount of fentanyl required was significantly lower in the nimodipine group than the control group (-71%, P less than 0.001), whereas the nifedipine group did not differ from the control group. Quality of intra-operative anaesthesia was comparable in the three groups with respect to clinical observations (amnesia, sweat, tears, pupils), and the post-operative course was similar in all patients as well. Cerebral activity during the nimodipine-supplemented opioid anaesthesia was higher in the faster frequency bands (13-30 Hz). Power level in the beta range was most pronounced in Group 1, whereas power in the alpha range was similar in the calcium channel-blocker groups. The major conclusion was that nimodipine but not nifedipine administration can reduce fentanyl requirements during surgical procedures without influencing the quality of anaesthesia.

Analgesia↗

PubMed1987

[Haemoseparation in heart surgery].

The Haemonetics Cell-Saver, a device developed for the recovery of autologous blood, was evaluated at our department, the major areas of concern being: quantity of blood salvaged, reduction in blood bank usage and possible monetary saving. In addition, various coagulation analyses were performed at frequent intervals. This study consisted of 292 patients undergoing cardiac surgery, who were randomly divided into two groups: 148 patients (group I) receiving autotransfusion (immediate centrifugation of oxygenator content after termination of cardiopulmonary bypass) were compared to 144 patients without autologous transfusion (group II). In the group of autotransfused patients, a mean of 2.27 units of bank blood were used throughout their entire hospital stay, as compared to 6.12 units of homologous blood in the other group (II) without autotransfusion. There were no significant differences between the two groups in respect of laboratory parameters and clinical course during the perioperative period. The data presented indicate a significant reduction in bank blood usage, thus protecting the patients from various hazards accompanying homologous blood transfusion (hepatitis, AIDS). Since the cost of Haemonetics software is recovered by 1.25 units of bank blood, a cost reduction of about US $135.-was achieved.

Blood Coagulation Tests↗

PubMed1987

[Nitrous oxide: modification of the hemodynamics in patients with coronary heart disease].

The haemodynamic effects of 70%, 50% and 30% N2O--compared to 100% O2--were studied in 20 patients undergoing coronary artery bypass grafting. The measurements-performed after an equilibration phase of 10 minutes--were made preoperatively but after induction of anaesthesia with 0.3 mg/kg bw etomidate, 0.01 mg/kg bw fentanyl and 0.1 mg/kg bw pancuronium bromide. In relation to N2O concentrations, mean arterial pressure (-4.8%), total systemic resistance (-7.9%) and stroke volume index (-6.4%) decreased moderately, whereas the cardiac index remained unchanged and the heart rate increased (+9.7). Total pulmonary vascular resistance was always within the physiological range, as were the triple index and the rate pressure product. In patients with coronary heart disease cardiovascular functions are compromised in close relation to the degree of the underlying disease. In accordance with other investigators, nitrous oxide should not be used in patients with impaired left ventricular function because of the possibility of deterioration of myocardial function. In such cases, amnesia should be achieved by means of other agents.

Anesthesia↗

PubMed1987

[Hemodynamic action profile of propofol in comparison with midazolam. A study in coronary surgical patients].

Propofol, a rapid and short-acting i.v. anesthetic, was associated with the risk of anaphylactic reactions in its original cremophor-EL formulation. It has been reformulated in a soybean emulsion with satisfactory anesthetic properties. A former study of hemodynamic changes after i.v. induction with propofol, thiopental, methohexital, etomidate, and midazolam in patients with coronary artery disease demonstrated that in comparison to other induction agents propofol depressed systolic and diastolic arterial pressures more severely, compromising coronary perfusion. In the present investigation left ventricular parameters as well as hemodynamic effects during extracorporeal circulation (ECC) were studied in comparison to midazolam during opiate analgesia. Methods. Hemodynamic effects of 2 mg/kg body weight propofol as compared to 0.15 mg/kg midazolam were studied in 34 patients during coronary artery surgery before cannulation of the large vessels (measurement of left ventricular parameters) or during ECC (measurement of arterial perfusion pressure and oxygenator volume). Results (see Table 1, Figs. 1 and 2). Propofol decreased systolic and diastolic pressures (-27%, -22%) more than midazolam (-10%, -9%). Cardiac index and stroke volume index were diminished following both drugs (propofol: -14%, -9%; midazolam: -15%, -11%); total systemic resistance was reduced significantly by propofol (-22%). Dp/dtmax was compromised more markedly by propofol (-24%) than by midazolam (-18%), but there was no significant difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗

PubMed1987

[Modified substitution of intracellular cations].

In order to ascertain the effect of modified supplementation of electrolytes and trace metals on intracellular uptake, 75 patients undergoing mitral valve replacement were randomly divided into three groups: group A (n = 25) received potassium and sodium chloride while group B (n = 25) was treated with potassium aspartate; in group C (n = 25), a balanced solution of electrolytes and trace metals (Inzolen) with aspartate as the anion was given. The treatment in the three groups was administered on the basis of frequently measured plasma levels of potassium and sodium. Anesthesia was similar in all patients; cardiac arrest was performed by crossclamping of the aorta using "Bretschneider's cardioplegia" for sodium withdrawal. After removal of the mitral valve, a sample of papillary muscle was obtained and analyzed by atomic absorption for its content of sodium, potassium, magnesium, zinc, and copper (Na, K, Mg, Zn, Cu). Sodium levels in papillary tissue were below the normal range in all groups and without differences depending upon the kind of treatment. Potassium levels in group A, however, (KCl) were markedly below those in groups B and C (aspartates). A similar effect could be observed with respect to tissue levels of Mg, Zn, and Cu. Supplementation of trace metals (group C) had no additional effect on tissue concentrations: there were no significant differences between group B (K aspartate) and group C (K-, Mg-, Zn-, Cu-, Na aspartate). Our results stress the importance of effective treatment of electrolyte and trace metal deficiencies. The present data suggest that the utilization of intracellular cations can particularly be improved by using solutions with aspartate as the anion.

Adult↗

PubMed1986

Isolation and the fluorometric, high-performance liquid chromatographic determination of tacrine.

Tacrine (THA; 1,2,3,4-tetrahydro-9-aminoacridine) is an anticholinesterase agent which has been used clinically, most recently in the treatment of Alzheimer-type dementias. This paper describes the methodology for the isolation and quantitation of THA at therapeutic levels in serum from human subjects. Using C18 Bond Elut columns and an HPLC/fluorometry system, this assay exhibits a considerable improvement in sensitivity over previous uv methods, and allows routine testing of THA levels in serum samples of reasonable volume from human subjects.

Aminoacridines↗

PubMed1986

The influence of extracorporeal circulation on extravascular lung water in coronary surgery patients.

The influence of extracorporeal circulation (ECC) on extravascular lung water (EVLW) was investigated in a total of 45 consenting patients undergoing coronary artery bypass surgery. The patients were subdivided into 3 groups according to positive fluid balance during ECC: 1. less than 500 ml; 2. 500 to 1500 ml; 3. 1500 to 3000 ml. Lung water measurement was performed intraoperatively using the thermal green-dye double indicator dilution technique, with indocyanine green and a microprocessed lung water computer, before and after ECC. In the group with high positive fluid balance during ECC (group 3) EVLW - increase was more pronounced (5.18 ml/kg----8.18 ml/kg) than in the groups with lower positive fluid input (group 1: 5.35 ml/kg----5.68 ml/kg, group 2: 5.56 ml/kg----6.70 ml/kg). Extravascular lung water increase was accompanied by a deterioration of pulmonary gas exchange demonstrated by the greatest decrease of paO2 in group 3 (490 mmHg----243 mmHg). No significant relationship of lung water changes to various hemodynamic parameters was observed in this study.

Body Water↗

PubMed1986

Closure of longitudinal sternotomy with absorbable sutures.

In a consecutive series of 150 patients who underwent open heart surgery, absorbable suture (PDS-Ethicon) were used for the closure of median sternotomy. One patient developed sternal dehiscence; wound complications or incompatibility with the suture material did not occur. With the technique of "double" PDS sutures, rapid and secure sternal closure can be performed even in cases of friability of the sternum without cutting through the sternal bone.

Cardiac Surgical Procedures↗

PubMed1986

[Volume replacement with a new hydroxyethyl starch preparation (3 percent HES 200/0.5) in heart surgery].

In a randomized study including 55 patients undergoing elective aorto-coronary bypass surgery efficacy of a low concentrated hydroxyethylstarch (3% HES 200/0.5) was tested after extracorporeal circulation (ECC). All patients received 1,000 ml autologous washed erythrocytes (cell saver) and 400 ml fresh frozen plasma (FFP). Thereafter patients were randomized into 4 groups. Hemodynamic parameters, laboratory parameters as well as extravascular lung water (EVLW - double indicator dilution technique) were measured before ECC as well as before and after infusion therapy. With regard to hemodynamic efficiency and the change in laboratory data no relevant differences between group I, II and III could be seen. EVLW-measurement demonstrated the lowest increase in lung water after infusion of HES; simultaneously pulmonary gas exchange was less compromised in comparison to the other infusion groups. 3% HES 200/0.5 solution can be considered as an effective volume substitute with short intravascular retention time, which seems to be of advantage in patients coming off extracorporeal circulation.

Blood Volume↗

PubMed1986

[Isolated modification of the vascular system by vasopressor agents (akrinor, etilefrin, ephedrine, norfenefrine, amezinium) during extracorporeal circulation in man].

The influence of different vasopressors (Akrinor, etilefrine, ephedrine, norfenefrine, ameziniummetilsulfate) on arterial perfusion pressure and oxygenator volume during extracorporeal circulation was compared to a control group. All substances led to an increase in perfusion pressure, thus demonstrating a direct influence on arterial vessels. The rise in arterial pressure after injection of ameziniummetilsulfate persisted during the investigation period, whereas norfenefrine led to a short-lasting, but massive increase. No rise in venous tone was noticed during the investigation period.

2-Hydroxyphenethylamine↗