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Biomedical subjects

K L Scholler

Publications and source records attributed to K L Scholler.

At least 19 recordsLinked to original sources
PubMed1991

[Pharmacokinetics of articaine in mandibular nerve block].

Up to now, mandibular nerve blocks have been carried out without knowing the exact blood concentrations resulting from the use of the local anesthetics. Due to the high vascularity a rapid increase in serum local anesthetic levels is to be expected. Due to analytical problems, the literature provides controversial statements about the pharmacokinetics of articaine which is generally used for this block. The given half-life periods following intramuscular application range from 39 min [8] to 31 h [6]. For this reason, mandibular nerve blocks with 2 ml 4% articaine with 1:200,000 epinephrine were carried out in 10 awake patients and 10 patients during intubation anesthesia. RESULTS. Blood samples from peripheral veins showed an average maximum concentration of 2.1 +/- 1.3 mg/l after 12.5 +/- 2.5 min. After 8 h the value had fallen below the minimum detection limit of 0.05 mg/l. In the present study, a half-life of approximately 20 min was determined for articaine after conduction anesthesia. This local anesthetic holds an exceptional position because as an amide-type local anesthetic it contains an additional ester group that is hydrolytically metabolized in the blood. The concentration of the resulting metabolite reaches a maximum value of 2.6 +/- 1.6 mg/l after 40 to 50 min. CONCLUSIONS. Compared to other amide-type local anesthetics, whose terminal plasma half-life varies between 1 and 3.6 h [5], the value of 20 min found for articaine is very low. This is in part due to its structure, as the ester group is rapidly metabolized by plasma esterases. Because of its rapid breakdown articaine is very suitable for use in oral surgery. The HPLC method represents an uncomplicated analytical technique for the determination of local anesthetics levels in blood and other body fluids.

Carticaine↗
PubMed1985

[Influence of the volume of peridural morphine bolus injections on morphine concentration in the cisterna magna of the dog].

14 dogs received randomly a bolus injection of either 2 mg morphine in 10 ml isotonic saline solution or 2 mg morphine in 1 ml isotonic saline solution epidurally at T6. An epidural infusion of 0.16 mg morphine/0.06 ml/h was applied immediately following the 1 ml bolus injection of morphine. Cisternal cerebellomedullary CSF samples were taken at varying intervals to determine free morphine immunoreactivity by radioimmunoassay. Within 20 min after the 10 ml bolus injection the peak CSF morphine concentration of 3594 +/- 910 ng/ml was reached. Following this, CSF morphine levels decreased exponentially and after 48 h 8 +/- 3 ng/ml were measured. The peak CSF morphine concentration of 139 +/- 51 ng/ml was, however, reached only after 2 h following the 1 ml bolus injection plus the infusion treatment. Despite the additional infused amount of 7.68 mg over 48 h the CSF morphine concentrations decreased also exponentially and after 48 h 16 +/- 4 ng/ml were measured. One may conclude, therefore, that the risk of respiratory depression is negligible under epidural infusion treatment following an initial "Low-Volume"-bolus injection of 2 mg morphine, a recommendable method for treating post-operative pain. High-volume bolus injections of morphine should generally be abandoned in epidural treatment of pain.

Animals↗
PubMed1984

[Is calcium indicated in resuscitation? Experimental studies in dogs].

This study compares the effect of epinephrine (11 dogs) with that of the combination of epinephrine with calcium (10 dogs) in CPR after anoxial cardiac arrest. In the epinephrine group resuscitation was successful in all 11 dogs within 4 minutes. In the calcium group only 7 out of 10 dogs could be resuscitated: 3 dogs died during CPR in cause of irreversible fibrillation (2 cases) and "stone heart" (1 case). High CPK-activity reflected severe myocardial cell damage. In the survivors of the calcium group cardiac function was significantly impaired: 1. decreased left ventricular pressure (LVP) and contractility (dp/dt max), 2. increased afterload, 3. decreased cardiac output inspite of increased heart rate, 4. as a consequence, reduced perfusion of the vital organs. - These results foster the conclusion that calcium should not be used henceforth in CPR. Epinephrine was and is still the drug of choice in resuscitation after cardiac arrest.

Animals↗
PubMed1983

[Are beta-sympathomimetic substances in resuscitation useful? Experimental studies].

Orciprenaline and epinephrine have been compared in cardiopulmonary resuscitation (CPR) in the dog. In a third group no substance was given. When orciprenaline was repeated without success, epinephrine was given. After administration of epinephrine left ventricular pressure and central aortic pressure were significantly higher. CPR was also more successful in epinephrine-treated dogs, a fact which can be attributed directly to these higher pressures. However, the attempt at resuscitation with orciprenaline, and, in the event of failure, with epinephrine, yielded significantly poorer results than treatment with epinephrine alone. Epinephrine substantially increased coronary perfusion pressure and coronary blood flow was adequate. When orciprenaline was administered, however, diastolic blood pressure decreased and no coronary blood flow could be measured. Serum CPK activity was increased. Ventricular fibrillation occurred just as often with epinephrine as with orciprenaline. In the epinephrine group defibrillation led directly to adequate circulation, whereas in the orciprenaline group subsequent electromechanical dissociation was observed. It is concluded that beta-receptor stimulators have no place in CPR. Epinephrine is the drug of choice in resuscitation after cardiac arrest.

Animals↗
PubMed1983

[Axillary plexus anesthesia in noncooperative patients].

In 36 non-cooperative patients we performed block of the axillary brachial plexus by using a well recognized catheter technique. A flexible, disposable intravenous cannula was placed into the axillary neurovascular sheath and used for injection of local anaesthetic solution without adverse sequelae. Analgesia for acute and elective surgical procedures was obtained rapidly and independent of any patient's assistance in all cases. Catheter axillary block seems to be a valuable anaesthetic technique in the difficult and risky management of non-cooperative patients.

Adolescent↗
PubMed1983

[Orciprenaline (Alupent) in resuscitation for circulatory arrest? Experimental comparison between orciprenaline and adrenaline in dogs].

This study compares CPR with orciprenaline (8 dogs), with epinephrine (11 dogs) and without any drug (8 dogs) in cardiac arrest caused by anoxia. Resuscitation was successful in all animals of the epinephrine group and in 2 of the orciprenaline group. Spontaneous circulation could not be restored in any of the control animals. There was no difference in the occurrence of ventricular fibrillation between the drug groups. No fibrillation occurred in the controls. On the other hand, the incidence of successful defibrillation was significantly higher with epinephrine. The superiority of epinephrine was due to its having effected a significantly higher diastolic pressure during cardiac massage. The diastolic pressure decreased after orciprenaline injection to such an extent that coronary underperfusion resulted with consequent rise of serum CPK. We conclude that the use of orciprenaline is contraindicated in cardiac arrest.

Animals↗
PubMed1980

[The metabolism of halothane under the influence of thiopental, methohexital, etomidate, enflurane and disulfiram under clinical conditions (author's transl)].

The biotransformation of halothane is supposed to be the cause of the rare "halothane-hepatitis". Therefore an inhibition of the metabolism of Halothane is of some interest. We used bromide as a metabolite of Halothane and investigated the bromide level of the serum of patients after halothane anaesthesia by means of x-ray fluorescence spectrometry. The induction of anaesthesia with Thiopental, Methohexital and Etomidate had no influence on the bromide level. Likewise the influence of Enflurane on the metabolism of Halothane was not significant. An effective inhibitor in man is Disulfiram. The authors assume, that further information about the toxicity of Halothane metabolites can be gained through further studies of drugs like Disulfiram.

Adolescent↗
PubMed1977

The use of serum cholinesterase in succinylcholine apnoea.

Fifteen patients demonstrating unexpected prolonged apnoea lasting several hours after succinylcholine have been treated by a new preparation of human serum cholinesterase. Adequate spontaneous respiration was re-established in an average period of ten minutes after the injection. In 12 patients biochemical genetic examinations confirmed the presence of an atypical serum cholinesterase. In three patients none of the usual variants were found. It is therefore supposed that other unknown variants of serum cholinesterase exist which cannot hydrolyze succinylcholine. The use of serum cholinesterase in succinylcholine apnoea provided considerable relief to both patient and anaesthetist.

Adolescent↗
PubMed1975

[The influence of ethrane on the electro- and pentylenetetrazol-convulsions in mice (author's transl)].

The influence of Ethrane upon electro shock and pentylenetetrazol-induced convulsions was studied in mice. Similar to other inhalation anaesthetics and to barbiturates Ethrane exerts a powerful anticonvulsive activity. There is a dose response relationship between the rate of electro shock (20 mA/0.2 sec) induced convulsions and inspiratory Ethrane concentration, convulsions being completely prevented by 1.5 vol.-percent of Ethrane. The LD(50) of pentylentetrazol increases five fold under a 2 vol.-percent Ethrane anaesthesia.

Anesthesia, Inhalation↗