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Biomedical subjects

G Hempelmann

Publications and source records attributed to G Hempelmann.

At least 451 records · Page 25Linked to original sources
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↗
PubMed1987

[Effect of premedication and fentanyl administration on the endocrine stress reaction during halothane anesthesia].

The influence of two different premedication regimens (diazepam versus pethidine/promethazine with fentanyl substitution before induction) on the endocrine stress-response during halothane anaesthesia was investigated in twenty orthopedic surgery patients. After premedication, the levels of plasma catecholamines, ADH, ACTH and cortisol were lower in the pethidine/promethazine-than in the diazepam-group. The levels of adrenaline remained significantly lower during the whole observation period. Thirty minutes after extubation all endocrine parameters except noradrenaline were lower in the pethidine/promethazine-group than in the diazepam-group.

Adolescent↗
PubMed1987

[Opinion of mothers on continuous peridural obstetrical anesthesia].

The general opinion on epidural anesthesia in obstetrics may be adversely affected by recent public controversies about the mother's situation during childbirth in hospital, which nowadays is often considered to be a highly technological, impersonal, or "unnatural" procedure. This assumption led us to conduct an inquiry on maternal assessment of obstetric epidural anesthesia and its relation to the clinical and social history. The study included 113 parturients, who received epidural anesthesia (on-demand epidural injections of bupivacaine 0.25%) for vaginal delivery. Mothers were asked to answer certain questions about this regimen (e.g. analgetic efficacy; difficulties in deciding on this method; recommendations to other parturients; opinion of the role of epidural anesthesia in obstetrics; choice of analgesic regimen for future childbirth) 1 day after delivery and 2 months later. Additional social and historical factors (e.g. education; profession; family status; preceding pregnancy, childbirth or abortion; complications during pregnancy or childbirth; duration of parturition) were used to reveal relevant statistical correlations. Sixty-five percent of the patients considered pain relief by epidural anesthesia as "good" or even "very good" during the first inquiry immediately after childbirth. Women who had undergone prior interruptions of pregnancy were less satisfied, probably because of their rather ambiguous attitude towards motherhood. With regard to the choice of analgesic regimen for future childbirth (50% of the patients had made a definite decision to have epidural anesthesia under this condition), those women were especially reserved who had suffered from complications during pregnancy and disapproved of it in the future.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Epidural↗
PubMed1987

[Effect of the calcium antagonist nimodipine on hemodynamics, gas exchange and endocrine parameters in opiate anesthesia].

During opiate anesthesia (standardized dosage of fentanyl) for operation of cerebral aneurysms after subarachnoid hemorrhage, different hemodynamic, respiratory, metabolic, and endocrine parameters were determined before (1 in Fig. 1-4), after (6), and during consecutive stages of induced hypotension (systolic blood pressure 100 mmHg (2), 90 mmHg (3), 80 mmHg (4, 5) during an interval of 20 min), comparing two groups with different vasodilating drugs. In the first group (nimo/NNP in Figs. 2-4) a constant infusion of nimodipine was applied (1.2 micrograms/kg b.w. X min-1), while sodium nitroprusside (NNP) was added in small amounts as necessary to achieve the respective values of systolic blood pressure. In the second group (NNP in Figs. 2-4) induced hypotension was done with NNP alone (maximal dosage: 8 micrograms/kg X min-1). Each group consisted of 11 patients. Additional nimodipine (in the first group), a calcium antagonist commonly recommended for preventing vasospasm and consequent neurologic deficits after subarachnoid hemorrhage, not only reduced the need for NNP, a vasodilating drug with potential toxicity, by 70%-80% as compared to the second group (Table 1). In addition, the cardiovascular situation was more stable in patients with nimodipine infusion: rapid variations of blood pressure and heart rate as well as tachyphylaxis and rebound, typical for NNP-induced hypotension, were avoided. Nevertheless, comparing the hemodynamic data at fixed stages of hypotension, there were only minor differences between both groups (Fig. 2). Reduction of blood pressure was due to a decrease in vascular resistance and was accompanied by an increase in cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed1987

[The endocrine stress-reaction to orotracheal intubation and topical anesthesia with lidocaine].

The influence of laryngoscopy and intubation with or without topical lidocaine anesthesia on the endocrine stress response was investigated in six groups of 40 orthopedic surgery patients differing in premedication and technique of lidocaine application (one- or two-step method). Controls were included without lidocaine application. Plasma levels of catecholamines (by HPLC) were measured before induction and 1, 5, and 10 min after intubation, ADH-levels (by RIA) before induction and 5 and 10 min after intubation. In addition, mean arterial pressure (MAP, MAP), HR, and the incidence of coughing and cardiac arrhythmias were observed. The statistical evaluation (analysis of variance with repeated measures on one factor) considered P values of less than 0.05 significant. There was no influence of laryngoscopy and intubation on plasma catecholamine levels during the observation period. A continuous decrease in both levels of epinephrine and norepinephrine was significant. ADH levels showed no significant changes. Lidocaine had no influence on these endocrine parameters. MAP and HR increased after intubation in all groups studied. The increase in HR was less pronounced after lidocaine treatment. Coughing (4 patients) and ventricular dysrhythmia (2 patients) were observed only in patients without lidocaine treatment. In conclusion, no influence of different modes of treatment on the endocrine stress response during intubation became obvious. There was no indication that the cardiovascular symptoms during laryngoscopy and intubation are caused by systemic stress. An explanation may be a direct neural impulse via sympathetic efferents to the heart. On the other hand, topical application of lidocaine did prevent coughing and cardiac irritation, and the increase in HR was attenuated.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
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

[Anesthesia procedures and perioperative patient monitoring in chemonucleolysis].

Premedication with H1 and H2 blockers as well as cortisone to reduce or prevent allergic reactions should be an integral part of the overall treatment. The facilities for immediate treatment of anaphylactic reactions including cardiopulmonary resuscitation must be readily available. Our haemodynamic measurements allow us to give a negative answer to the question--so far not investigated in man--whether the use of chymopapain or of its fragments leads to constant cardiocirculatory effective reactions in the early phase. Our experiences collected so far favour catheter peridural anaesthesia as the method of choice in chemonucleolyses.

Anesthesia↗
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↗