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Biomedical subjects

H Suttmann

Publications and source records attributed to H Suttmann.

11 recordsLinked to original sources

[Beta activation following the intravenous administration of benzodiazepines and the specific antagonist flumazenil (Ro 15-1788)].

In a prospective randomized study involving 32 male subjects aged 18 to 38, the effects of flunitrazepam (0.25 to 2 mg/70 kg), lormetazepam (0.5 to 4 mg/70 kg), midazolam (1.5 to 12 mg/70 kg) and diazepam (4 to 32 mg/70 kg) on the beta-activity (13 to 20/s) were investigated. Each subject received four benzodiazepine injections of increasing dosage. The doses were selected so that the lowest had only a slight effect on the test person's condition, while the highest resulted in deep sedation. The increase in beta-activity started off with a latency of 30 to 60 s; it was proportional to the dosage and reached its maximum between the 2. and 3. minutes. The subsequent decrease in beta-activity could be represented by an exponential function. The effect could be cancelled temporarily by administering repeated doses of the specific antagonist, flumazenil (0.1, 0.3 and 0.9 mg/70 kg). The method is suited for describing pharmacodynamic processes, determining equipotential doses of benzodiazepines and detecting the interaction between benzodiazepines and specific antagonists.

Adult

[The effect of propofol-ketamine anesthesia on hemodynamics and analgesia in comparison with propofol-fentanyl].

Propofol (Diprivan), a modern intravenous hypnotic, produces a reduction in both cardiac index (CI) and mean arterial pressure (MAP). Ketamine (Ketanest), a potent analgesic, in contrast, causes an increase in MAP and CI. The aim of the present study was to investigate whether the combination of propofol and ketamine can give better hemodynamic stability during the induction and maintenance of general anesthesia than propofol used with fentanyl, whose cardiodepressant actions may cumulate. METHODS. For induction of general anesthesia 10 patients (ASA I and II) each received 3-5 boluses of propofol (0.5 mg.kg-1 during 35 s until predetermined level of anesthesia was reached (stage D2/E0 according to [20]) followed by a continuous propofol infusion (0.120 mg.kg-1.min). Fentanyl 0.1 mg was administered to each patient in group A for induction of anesthesia and again if evident pain was present. In group B ketamine was given following a pharmacokinetic model based on computer-simulated calculation. After an initial bolus of 38 mg injected within 2 min further doses of 42 mg, 35 mg, 32 mg and 28 mg ketamine were administered over 30 min at a time. Signs of evident pain were treated by means of supplementary doses of 0.5 mg.kg-1. RESULTS. In both groups a moderate drop of MAP was observed after the induction of general anesthesia. Two patients in each group showed a distinct decrease in MAP (-32%). The heart rate dropped slightly (-9%) in group A, but did not change in group B. Following intubation the MAP rose by less in group A (+8%) than in group B (+21%). After the beginning of the operation the group treated with propofol/fentanyl showed major hemodynamic changes; in particular, bradycardia with less than 40 bpm was observed in more patients than in the propofol/ketamine group. Postoperatively, fewer patients in group B required rescue doses of analgesics (1 of 10) than these in group A (7 of 10), though vigilance was better in group B. DISCUSSION. The dose of ketamine administered during the induction of general anesthesia may have been not high enough to neutralize the cardiodepressant effect of propofol. But during the maintenance of anesthesia there was in fact better hemodynamic stability in group B than in group A as a result of the neutralization of opposing actions. Fentanyl even intensified the fall in MAP after propofol. Patients in group B showed better vigilance as well as better pain relief postoperatively. The population of the fentanyl group was obviously more deeply sedated and analgesia was still inadequate. In our study general intravenous anesthesia with propofol and ketamine offered the advantages of better analgesia, a higher state of vigilance and the absence of respiratory depression during the postoperative phase compared with the combination of propofol and fentanyl.

Analgesia

[Etomidate using a new solubilizer. Experimental clinical studies on venous tolerance and bioavailability].

Pain following intravenous injection as well as thrombophlebitis are substantial side effects of etomidate that have been reported from the first clinical study (1972-1973) onwards. Investigations of our own and by Gran et al. have pointed out that injectable etomidate with intralipid as a solvent removes side effects without impairing the good hypnotic action. The idea of using a lipid emulsion as a solvent was presented a few years later, inducing two further studies. METHOD. Both pharmacodynamic (continuous EEG registration) and pharmacokinetic [determination (HPLC) of plasma levels of the active substance] investigations were carried out on volunteers. At random 16 volunteers received etomidate in propylene glycol or etomidate in lipid emulsion for general anesthesia. A dose of 0.3 mg kg-1 was given over 60 s. In a clinical study 100 patients were divided into two independent groups of 50 each. They received either the commercially available etomidate in 35% propylene glycol (group I) or the new formulation containing 20 mg etomidate in 10 ml of a lipid-emulsion (Lipofundin MCT 20%) (group II). A dose of 0.3 mg kg-1 etomidate was given. RESULTS. There was a higher concentration of etomidate for 8 min after injection in lipid emulsion compared with etomidate in propylene glycol. The plasma concentration of etomidate (200 ng/ml) correlates with C2 corresponding to the light sleep stage after etomidate in propylene glycol, but with D0 according to the deep sleep stage after etomidate in lipid emulsion. At lower plasma concentrations, the hypnotic action of etomidate in propylene glycol is stronger than the effect of the lipid emulsion. This result means that it is possible that a part of the etomidate remains in the lipid particles. In the clinical study the anesthetic induction time was nearly identical in both groups; blood pressure and heart rate were stable. Following etomidate in propylene glycol, 36% of the patients complained of a painful injection. On the first postoperative day, 9 of 47 patients showed signs of phlebitis and three others thrombosis. On the 7th day a venous reaction was evident in 22% of these patients; 2 patients had developed phlebitis, 5 thrombosis and 4 thrombophlebitis. After etomidate in lipid emulsion, there were no signs of local irritation. The same results have been obtained in the study with volunteers. CONCLUSION. Two unpleasant side effects of etomidate, pain on injection and postoperative thrombophlebitis, were abolished by the solvent "lipid emulsion".

Adult

[Visual EEG analysis in controlling intravenous anesthesia using propofol].

Since the discovery of brain waves by Berger, repeated efforts have been made to use the electroencephalogram EEG for monitoring and controlling anesthesia. Owing to its susceptibility to failure and the high expenditure regarding technology and personnel, the technique has not yet been adopted in routine anesthesia, however. In the study now reported an attempt was made to apply the positive experience with the recording and interpretation of EEG in the development of new anesthetic agents in the experimental laboratory, during routine clinical operations. The anesthetic used in the study was Propofol, an induction hypnotic that has only recently been introduced, together with nitrous oxide and repeated doses of fentanyl. Propofol is distinguished by its fast onset of action and short inactivation time; it is therefore suitable for induction and maintenance of anesthesia. The aim of the study was to maintain predetermined stages of sleep during anesthesia with the aid of visual on-line analysis of the EEG and to establish the dose of Propofol required for this purpose. The operations-general and orthopedic surgery-lasted 70-190 min (average duration: 120 min). In accordance with the randomization plan, the maintenance dose of Propofol was controlled in such a way that in ten patients light sleep levels (C0 to D1) and in the other ten deep sleep levels were maintained. The EEG was recorded via five active scalp electrodes (FP2, F4, C4, P4, O2) with reference to a joint electrode (A2). The stages of sleep were classified according to Kugler.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[A new formulation of etomidate in lipid emulsion--bioavailability and venous provocation].

In a prospective, randomized study of 16 volunteers, a new galenic formulation of the induction hypnotic etomidate in lipid emulsion was compared with the commercial form in propylene glycol (Hypnomidate). After 0.3 mg/kg etomidate plasma levels (HPLC) and hypnotic effects (visual EEG analysis) of both formulations were almost identical. Onset of action occurred after 41.6 s in the propylene glycol group (group I) and 35.6 s in the lipid emulsion group (group II). The hypnotic effect (greater than or equal to D0) lasted 7 min 20 s in group I and 6 min in group II. Plasma levels in group I decreased from 630 ng/ml after 2 min to 170 after 8 min and 37 after 130 min. With group II the plasma levels decreased from 770 ng/ml after 2 min to 150 after 8 min and 42 after 130 min (Fig. 1). In the propylene glycol experiment, 4 of 8 volunteers reported pain on injection. Within 7 days 4 persons developed phlebitis or thrombophlebitis. One showed signs of an allergic reaction (urticaria). With the new formulation of etomidate in lipid emulsion, neither venous sequelae nor allergic reactions were observed in any of the 8 volunteers (Table 2).

Adult

[Patient-controlled analgesia. A technical toy or a contribution to the treatment of pain?].

PCA (patient-controlled analgesia) was used to treat postoperative pain after general surgery and gynecological operations in a total of 82 patients. In a prospective randomized study, 20 of these patients received pentazocine and 20 were treated with Fentanyl. The bolus quantity for pentazocine was 15 mg in 5 ml NaCl, and that for Fentanyl 0.05 mg in 5 ml NaCl. A maximum of 3 boluses was allowed within 1 h; the refractory period was 5 min. Both drugs were equally suited for the treatment of pain. With pentazocine, an average of 144 micrograms kg-1 min-1 was administered during the first 16 h after the operation; with Fentanyl, the quantity taken was 0.78 microgram kg-1 min-1. The inter- and intraindividual variance in the consumption of analgesics described by other authors was confirmed. The amount of analgesics required ranged between 0.05 and 1.95 mg for Fentanyl and between 15 and 435 mg for pentazocine in a period of 16 h. Three patients did not request an analgesic at all. The average consumption of analgesics constantly decreased in the first few postoperative hours, from 0.28 mg every 4 h after the operation to 0.18 mg every 4 h 16 h later (Fentanyl) and from 55 mg every 4 h after the operation to 31.5 mg every 4 h 16 h later (pentazocine). The majority of patients reported very positive experience with PCA. There were few side effects. Problems arose from the negative attitude of other doctors and the nursing staff, and from some misunderstandings.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[Computer-controlled infusion].

For complex treatment regimens in the field of modern infusion therapy and for the administration of potent drugs (liquid management), a special microcomputer (Infucommand III) has been developed which makes it possible to control commercial infusion pumps via a standardized interface. By this means, infusion pumps can be combined with other medical instruments or further pumps to form an intelligent unit. Due to its small dimensions and few operating elements, the control device is easy to handle. A high safety standard has been achieved in routine operation, from the aspects of both hardware and software. Large memories (ROM and RAM) enable a large number of different user programs to be stored. In initial clinical trials the devices have already stood the test with regard to patient-controlled and EEG-controlled-anesthesia.

Humans

Concomitant increase in plasma atrial natriuretic peptide and cyclic GMP during volume loading.

To investigate the effects of fluid expansion on endogenous atrial natriuretic peptide (ANP) and cyclic 3',5'-guanosine monophosphate (cGMP), four male volunteers were studied before, during and after intravasal volume loading. Volume expansion was performed by intravenous infusion of 2,000 ml isotonic saline solution within 30 min. Mean plasma ANP levels increased 2.5-fold from 31.2 pg/ml to 81.7 pg/ml 40 min after the start of infusion. Plasma cGMP levels paralleled the rise in ANP, showing a mean cGMP increment from 2.7 pmol/ml to a maximum of 8.2 pmol/ml. Both ANP and cGMP levels were back to basal levels 120 min after termination of the infusion. Stimulation of endogenous ANP release by volume loading suggests that ANP is involved in the regulation of fluid homeostasis in man. The parallel rise in plasma cGMP levels supports the idea that cGMP is a mediator for the effects of ANP.

Adult