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Biomedical subjects

U Börner

Publications and source records attributed to U Börner.

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

[Endocrine stress response in halothane, enflurane and isoflurane anesthesia in surgical interventions].

The endocrine stress response under inhalation anesthesia with halothane, enflurane, and isoflurane was investigated in 30 patients during and after orthopedic surgery (Table 2). Plasma levels of adrenaline and noradrenaline (by HPLC/ECD), ADH, ACTH, and cortisol (by RIA), glucose, lactate, and free glycerol were determined before induction of anesthesia, 10 min after intubation, 10 min before the end of the operation, and 5 and 30 min after extubation. Statistical evaluation was undertaken by analysis of variance with repeated measures on one factor. P values of less than 0.05 were considered significant. There were no significant differences in the concentrations of plasma catecholamines (Table 4, Figs. 1 and 2), ADH, ACTH (Table 5, Figs. 3 and 4), or cortisol before and during surgery between the groups. ADH was lower in the halothane group 5 and 30 min after extubation (P = 0.05), which might be due to the prolonged elimination of halothane after anesthesia. Blood pressure, heart rate (Table 3), and plasma concentrations of glucose, lactate, and free glycerol (Table 6) were comparable in all groups. It is concluded that for clinical practice halothane, enflurane, and isoflurane are comparable in their influence on the surgical stress response.

Adrenocorticotropic Hormone↗
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

[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

Thoracic peridural block in experimental endotoxin shock.

The influence of thoracic peridural block (PDB) on the metabolic and hemodynamic changes in endotoxin shock were investigated in rabbits. During the first 6 h of endotoxin shock, sensomotoric and sympathetic blockade distal to spinal segment T4 was achieved by intermittent administration of bupivacaine into a thoracic peridural catheter. The increase of plasma glucose, lactate, and free glycerol 2 h after endotoxin (50 micrograms/kg) administration was prevented by PDB. Animals with PDB had an accelerated clearance of glucose as indicated by a shorter plasma half-life of intravenously injected glucose (0.33 g/kg) 1 h after endotoxin administration. Hemodynamic parameters were measured during the first 210 min after endotoxin application. Compared with controls, PDB reduced mean arterial pressure and total peripheral resistance. PDB did not affect the initial increase of right ventricular pressure or the progressive decrease in O2 consumption and cardiac output after the endotoxin injection. The mortality at 24 h was not significantly reduced by the PDB (controls, n = 22: 68%; PDB, n = 21: 57%). The results demonstrate that thoracic PDB effectively blocks the sympathetic response in endotoxin shock. Hence, PDB causes peripheral vasodilatation, and, moreover, the metabolic data are consistent with an inhibition of the reactive glycogenolytic and lipolytic responses in shock. Although PDB altered the metabolic disturbances caused by endotoxin shock, mortality was not significantly affected.

Animals↗
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↗
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↗
PubMed1986

[Spasticity treatment with spinal morphine or midazolam. In vitro experiments, animal studies and clinical studies on compatibility and effectiveness].

Recent pharmacological investigations have support the hypothesis that spinal modulation of nociception as well as motor coordination is related to the activity of spinal interneurons and that certain spinal transmitters are involved in the control of both regulatory systems. Opioids and benzodiazepines, i.e. endorphin- or GABA-induced mechanisms, may be of importance for spinal treatment of spasticity in the near future. In order to clinically evaluate the interactions of these spinal processes we performed in vitro-experiments, animal studies and clinical investigations on the compatibility and antispastic efficacy of spinally administered opiates and benzodiazepines. Preclinical studies on tissue- and CSF-tolerance of different benzodiazepines (pH, tonometry, turbidimetry, histological findings in animals) are in favour of midazolam, a water-soluble compound, which is active against pharmacologically induced spasms in animals (strychnine application in cats with chronical catheterization of the subarachnoid space) after lumbar intrathecal injection. Using an appropriate dosage of intrathecal midazolam selective blockade of spasticity of the hind legs may be demonstrated with integrated EMG. Clinical investigations (neurological assessment using rating scores for spasticity) in 16 patients, including a double-blind comparison of epidural morphine or midazolam, indicate that both drugs are effective against spinal spasticity of different origin. Efficacy of spinally applied agents depends on the severity of spasms and on the duration and extent of systemic pretreatment.

Animals↗
PubMed1986

[Intra- and postoperative interactions between the 2 opioids fentanyl and buprenorphine].

In order to demonstrate pharmacokinetic and pharmacodynamic interactions between fentanyl and buprenorphine, 3 groups of patients (n = 30) were compared, receiving either fentanyl (0.005 mg/kg b.w.) or buprenorphine (0.01 mg/kg b.w.) or both opioids as analgesic during surgery for disc protrusion. For a period of 4 h haemodynamic parameters were monitored and blood samples were taken for determination of the following concentrations: ADH, ACTH, cortisol, glucose, unbound glycerol, fentanyl and buprenorphine. Blood gas analyses were performed up to 2 h postoperatively. Although in all groups haemodynamic parameters were constant, there was an increase in factors related to operative stress (cortisol, glucose, unbound glycerol, postoperative acidosis) after the combination of both opioids, while postoperative ventilatory parameters in this group were not improved by the partial agonist buprenorphine. Plasma levels were not affected by combined application, except for a slight elevation of buprenorphine concentrations during additional use of fentanyl. Buprenorphine, at least in higher dosages, seems to antagonize analgesia induced by fentanyl, although respiratory depression is even more pronounced. It may be assumed, that with partial agonists the relation of agonistic and antagonistic activity may be different, depending on the dosage used and on the respective pharmacologic effect observed during investigation.

Acid-Base Equilibrium↗
PubMed1986

[Airway pressure and transcutaneous O2 and CO2 partial pressure as monitoring measurements for high-frequency jet ventilation?].

Two different methods of measuring airway pressures (n = 7), and the usefulness of transcutaneous pO2 and pCO2 measurement (n = 9) in monitoring High Frequency Jet Ventilation (HFJV), were investigated in critically ill patients. Airway pressures obtained by tip manometer from different points within trachea and mainstem bronchi during HFJV (f = 100/min, inspiratory time 40%, FIO2 0,4, minute volume 25.6 +/- 5.2 l) were nearly identical with pressures obtained from the integrated pressure line of HI-LO-JET endotracheal tubes (R = 0.9638). There was no difference between proximal and peripheral airway pressures. When using a PEEP-valve, rather high values of PEEP may occur due to gas trapping. There was sufficient correlation between transcutaneous and arterial pO2 (R = 0.7573) and poor correlation between transcutaneous and arterial pCO2 (R = 0.4987). paO2 values were 51.1% above, paCO2 values 33.4% below transcutaneous values. Transcutaneous measurement of pO2 and pCO2 is only an additional method in monitoring HFJV which can reveal rough trends but cannot replace blood gas analysis.

Adult↗
PubMed1986

[High frequency jet ventilation in patients with acute respiratory failure. A comparison with conventional artificial respiration].

The major advantage of High Frequency Jet Ventilation (HFJV) in the treatment of patients with ARDS was commonly seen in better oxygenation and lower airway pressures, compared to conventional ventilation. Furthermore, HFJV seemed to be successful even in those patients in whom conventional ventilation had failed. We compared HFJV (f = 100/min, inspiratory time 40% to 50%) to conventional ventilation (f = 10/min, PEEP 5 to 10 cm H2O). For mean airway pressure and FIO2 equal values were chosen in both ventilatory modes. With HFJV paO2 was significantly (P less than 0.01) lower (82.2 +/- 28.2 mmHg compared to 139.2 +/- 23.5 mmHg), intrapulmonary shunting higher (29.2 +/- 19.6% compared to 15.3 +/- 6.4%) than with CV. Ventilatory volume required for normocarbia under HFJV was 25.6 +/- 5.4 l/min approximately equal to 341 +/- 81.8 ml/kg B.W. Pulmonary artery pressure (PAP 25.0 +/- 5.0 mmHg compared to 19.9 +/- 4.7 mmHg), central venous pressure (10.5 +/- 4.2 mmHg compared to 8.8 +/- 3.0 mmHg), pulmonary capillary pressure (13.3 +/- 4.4 mmHg compared to 11.3 +/- 3.7 mmHg), pulmonary vascular resistance (131.4 +/- 55.0 dyn . s . cm-5 compared to 96.7 +/- 33.7 dyn . s . cm-5) and right cardiac work index (1.38 +/- 0.55 kg . m/m2 compared to 1.05 +/- 0.33 kg . m/m2) were significantly increased (P less than 0.01) under HFJV. The other haemodynamic variables showed no difference between the two ventilatory modes. HFJV was inferior to conventional artificial ventilation in all patients and caused severe hypoxia in several patients, leading to pulmonary vasoconstriction and increased work of the right heart.(ABSTRACT TRUNCATED AT 250 WORDS)

Critical Care↗
PubMed1985

[Effect of an introductory dose of etomidate, methohexital and midazolam on adrenal cortex function before and after ACTH-stimulation].

The adrenocortical function after induction of anaesthesia using either etomidate, methohexital or midazolam was examined in 30 patients undergoing open heart surgery (ACVB). Midazolam and methohexital did not suppress the typical stress response assessed from the magnitude of the ACTH, cortisol and aldosterone levels. The ACTH-test was also normal. In contrast, induction of anaesthesia using etomidate led to a progressive fall in cortisol and aldosterone accompanied by an increase in ACTH. The ACTH-test resulted in only a minor increase in adrenocortical hormones. Thus an induction dose of etomidate, in contrast to methohexital and midazolam, markedly alters the normal function of the adrenal cortex. This side-effect of etomidate lasts for at least 4 hours but is no longer detectable after 24 hours.

Adrenal Cortex↗
PubMed1985

[Hemodynamic effects following bolus administration of different vasopressive agents for blood pressure stabilization during peridural anesthesia].

Vasopressors are often used to counteract hypotension induced by sympathetic blockade during epidural or spinal anaesthesia. This study contains data of invasive haemodynamic investigations following single-shot applications of different vasoconstrictor agents (Akrinor, etilefrine, ephedrin, norfenefrin, amezinium) during a combination of epidural block and controlled ventilation with oxygen and nitrous oxide. In a preceding dose finding study equipotent dosage of the substances used was confirmed. Usually bolus application of these vasopressors causes only a short-lasting circulatory stimulation, which does not cover the whole period of sympathetic blockade (exception: amezinium). Even small doses of drugs acting only upon alpha-receptors, may cause unwanted peripheral vasoconstriction and decrease of the already lowered cardiac output (example: norfenefrine). The rise of blood pressure after betamimetics may be delayed by an initial vascular beta 2 stimulation (example: etilefrine). In other sympathetic stimulants venoconstriction and therefore improvement of cardiac output by increase of preload takes place after an interval of some minutes to cardiac stimulation (example: ephedrin, Akrinor). Though the use of vasopressor agents during central blockade cannot be recommended in general, substances with alpha- as well as beta-stimulation should be preferred, if necessary. When using substances with short duration of action continuous infusion has to be taken into consideration.

2-Hydroxyphenethylamine↗
PubMed1985

[Colloid osmotic pressure and extravascular lung water following extracorporeal circulation].

With regard to Starling's equation, two factors are important for fluid regulation in pulmonary tissue: colloid osmotic pressure (COP) and hydrostatic pressure (PCP). The purpose of the study was to evaluate the relationship between COP, COP-PCP-gradient and extravascular lung water (EVLW) immediately after extracorporeal circulation (ECC). 39 consenting patients undergoing elective aorto-coronary bypass surgery received 1000 ml washed erythrocytes (w.e.; cell saver) +400 ml fresh frozen plasma (FFP) after ECC. Additionally, group I (n = 15) received 300 ml albumin 20%, group II (n = 13) 500 ml plasmaexpander (3% HES 200/0.5) and group III (n = 11) no more volume. At three different times, measurement of EVLW was performed by using double-indicator-dilution technique with indocyanine green and a microprocessed lung water computer: 15 minutes after ECC (before infusion), 45 minutes after ECC (after infusion), five hours after ECC. Application of 20% albumin led to a significant increase in COP (+67%) which was less pronounced in group II (+40%) and group III (+41%). Simultaneously, the most pronounced increase in EVLW could be observed in group I (+25%) as well. Pulmonary gas exchange in group I was more compromised (PaO2 -72 mmHg) than in group II (-38 mmHg) and group III (-50 mmHg). No correlation between EVLW and COP-PCP-gradient could be observed. In spite of a significant elevation of COP by using 20% albumin solution, EVLW increased with subsequent deterioration of pulmonary gas exchange. The presented data demonstrate no advantage of albumin 20%; if volume substitution is necessary after ECC, low concentrated plasmaexpanders (up to 10 ml/kg b.w.) may be preferred for several reasons.

Blood Proteins↗
PubMed1985

[Serum endotoxin level in the course of open peritonitis treatment].

In 27 patients with severe diffuse purulent or fecal peritonitis planned relaparotomies with peritoneal lavage or continuous dorsoventral lavage with open abdomen were performed after surgical treatment of the primary infection. During the course of the lavage treatment serum endotoxin was measured daily. The endotoxin-induced liberation of lysosomal proteases was studied by determining the elastase from polymorphonuclear leucocytes. 16 surviving patients showed decreasing endotoxin levels and decreasing elastase concentrations during the course of abdominal lavages. Planned peritoneal lavage and continuous dorso-ventral lavage seem to have the same potency in eliminating endotoxin from the infected peritoneal cavity. In letal courses endotoxinemia either persisted at high levels or even progressed inspite of lavage treatment.

Adolescent↗
PubMed1985

[Experiences with "etomidate pro infusione" in heart surgery interventions with extracorporeal circulation].

The results of experimental studies with etomidate demonstrating positive hemodynamic effects as well as a decrease in intracranial pressure induced a study using etomidate during cardiac surgery. This randomized study including 506 patients should prove the influence of etomidate on the rate of psychic disturbances after cardiac surgery. Patients treated with etomidate received a loading dose of 1 mg/kg b.w. etomidate within 15 minutes followed by a continuous infusion of 1 mg/kg b.w./h until the end of ECC. Patients without etomidate were the control group. Psychic disturbances were observed in 25% of the control group and in 30% of the etomidate group. In both groups of patients there was a fair number of patients with perioperative cardiopulmonary problems (artificial ventilation longer than 24 hours; catecholamine therapy: epinephrine greater than 5 micrograms/min longer than 3 hours): 8% in the control group and 20% in the etomidate group. These results indicate that etomidate does not beneficially influence the rate of psychic disturbances after open-heart surgery; it may induce, however, cardiopulmonary side effects after cardiac surgery. The results of recent studies indicating drug induced adrenal insufficiency are discussed.

Adolescent↗