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Biomedical subjects

K van Ackern

Publications and source records attributed to K van Ackern.

86 records · Page 5Linked to original sources
PubMed1975

[Effects of amantadine on heart and circulation].

The effect of amantadine-hydrochloride on heart and circulation is studied in 7 anesthetized, otherwise normal dogs with a mean body weight of 27.2 kg and in 8 heart-lung preparations of dogs. Arterial blood pressure, right atrial pressure, cardiac output and heart rate are measured and continuously monitored. Stroke volume and peripheral resistance are calculated. Left ventricular peak- and enddiastolic pressure, the rate of rise of intraventricular pressure and t-dp/dt are additionally measured in the heart-lung-preparations. Below 3 mg with kg(-1) in anesthetized dogs and 10 mg in the heart-lung preparation, respectively, a positive inotropic effect of amantadine is observed. This effect is caused by a liberation of catecholamines. Higher dosage of amantadine decreases cardiac contractility significantly. Therefore the negative inotropic influence of the drug itself has to be distinguished from the indirect sympathomimetic effect resulting from local release of myocardial catecholamines. Cardiac arrhythmias which occur in several experiments, can mostly be eliminated with propranolol or other drugs like lidocaine or sparteinsulphate.

Amantadine↗
PubMed1975

[Circulatory changes during preoperative isovolaemic haemodilution with a mixed solution of hydroxyethyl starch and 5% human albumine. A clinical study (author's transl)].

The influence of preoperative isovolaemic haemodilution on the circulation was examined in a clinical study. Heart rate, mean arterial pressure, mean pulmonary arterial pressure, cardiac output as well as haemoglobin and haematocrit values were determined. Stroke volume, total peripheral resistance, and the modified tension-time-index were calculated. A mixture of human albumin 5% and hydroxy-ethyl-starch was used as a solution for dilution. During the dilution phase the cardiac output increased compensatorily to the decrease of haemoglobin and the haematocrit values. While the heart rate and the mean arterial pressure remained unchanged the total peripheral resistance was reduced. Considering the described conditions and contraindications, preoperative isovolaemic haemodilution is a suitable method to replace an intraoperative blood loss of up to 2000 ml autologously. Thus a posttransfusion hepatitis can be avoided. In addition, preoperative isovolaemic hemodilution improves the microcirculation and may have a prophylactic effect on the thrombosis in the postoperative phase.

Blood Circulation↗
PubMedDate not supplied

[The rationale of pain therapy in the aged].

Today elderly persons represent the largest group of pain patients. Geriatric patients show different pharmacokinetic and pharmacodynamic features of local and systemic analgetic drugs, but there is no evidence that pain threshold changes with the age. The advanced knowledge of the physiological processing of pain (i.e. the role of prostaglandins) influences the treatment and the use of certain drugs. A successful therapy for elderly patients needs a planned action, starting with an exact analysis of the patient's social background, organic functions and pain status. During the course of therapy the patient needs a continuous guidance and his family should have thorough informations to reach an optimal effect. If there is no indication for electrotherapy or regional blocks, we start with a peripherally acting nonnarcotic analgesic. The next step is a combination between this drug and a psychopharmacon. If necessary we add narcotics of the partial agonist type. In case this is not effective we combine a psychopharmacologic agent with a potent agonist narcotic (like morphine). The next step includes the different kinds of spinal opiate application. With these methods we are able to carry out pain therapy (even in difficult cases) providing a high level of well-being, combined with a high grade of physical mobility and mental alertness.

Analgesics↗