Der Anaesthesist
-
Randomized Controlled Trial Comparative Study Clinical Trial
[RO 48-6791--a short acting benzodiazepine. Pharmacokinetics and pharmacodynamics in young and old subjects in comparison to midazolam].
The objectives of the present study were to compare in a randomized double-blind crossover study design the concentration-effect relationships of Ro 48-6791, a new benzodiazepine agonist, and midazolam, following infusion in young and elderly male volunteers. Therefore, linearly increasing plasma concentrations were generated by computer controlled infusion pumps to achieve a deep hypnotic effect. The endpoint of the infusion was defined by loss of response to loud verbal commands and a median frequency of the recorded EEG power spectrum below 4 Hz. ⋯ The major advantages of Ro 48-6791 compared to midazolam were its shorter duration of action as well as the faster recovery and thus the better controllability. Further investigations would have to confirm these results in a greater number of patients. The applied method of pharmacokinetic-pharmacodynamic modeling not only allowed to quantify the efficacy of Ro 48-6791 but also provided data to augment the safety for further investigations.
-
Randomized Controlled Trial Comparative Study Clinical Trial
[Comparison of sufentanil-propofol-anesthesia with fentanyl-propofol in major abdominal surgery].
Major abdominal surgery often leads to a marked sympathoadrenal stress response with high concentrations of plasma catecholomines, hypertension, and tachycardia. We compared the effects of sufentanil-propofol with fentanyl-propofol anaesthesia in a controlled, randomised, double-blind study of 18 ASA I-II patients aged 23-64 years undergoing major abdominal surgery. Study parameters were haemodynamics (heart rate [HR], arterial [ABP], central venous, and pulmonary arterial pressures, cardiac index [CI]), arterial catecholamine concentrations, and the median frequency of the electroencephalogram (EEG) power spectrum. ⋯ With both regimens, the sympathoadrenal stress response to major abdominal surgery was nearly completely suppressed, resulting in stable haemodynamics during the operations. Sufentanil and fentanyl were equally well suited as analgesic components of total i.v. anaesthesia with propofol.
-
Randomized Controlled Trial Clinical Trial
[Thromboembolism prevention with low dose heparin and spinal anesthesia--a risky combination?].
Spinal or intracranial haematoma is a rare but severe complication of spinal/epidural anaesthesia with an incidence of less than 1:100,000. Coagulation defects, traumatic puncture, and anticoagulant drugs are assumed to be risk factors for the development of this kind of haematoma. Whether the risk of bleeding after spinal/epidural anaesthesia is increased by the administration of low-dose heparin (unfractionated or fractionated) for thromboprophylaxis is currently under discussion. ⋯ We suggest that the development of spinal or intracranial haematoma after spinal/epidural anaesthesia is a multifactorial event. An influence of low-dose heparin prophylaxis as a cofactor cannot wholly be excluded because of the difficulty of studying the problem in a prospective way. The few case reports have to be seen in the context of millions of patients who have received either unfractionated or LMW heparin and lumbar or thoracic regional anaesthesia without any complication. We conclude that low-dose heparin prophylaxis (fractionated or unfractionated) is not a definite contraindication to spinal/epidural anaesthesia. High-risk (ASA III/IV) patients in particular benefit from effective postoperative analgesia achieved by local anaesthetics in combination with effective heparin thromboprophylaxis. Nevertheless, the absolute contraindications for regional anaesthesia must be respected and an individual risk/benefit analysis should be performed for every patient. An adequate time interval between application of heparin and regional anaesthesia or removal of a spinal/epidural catheter, atraumatic puncture technique, and careful neurologic monitoring during the post-operative period can minimise the risk of complications.
-
Randomized Controlled Trial Clinical Trial
[Propofol and etomidate-Lipuro for induction of general anesthesia. Hemodynamics, vascular compatibility, subjective findings and postoperative nausea].
Etomidate has become an important induction agent in high-risk patients because of its cardiovascular stability. Its unwanted side-effects such as pain on injection and thrombophlebitis could be significantly reduced by a new (medium chain triglyceride and soya bean) emulsion formulation. Propofol is solved in a mixture of long chain triglyceride and soya bean emulsion. In this double-blind, randomized study we compared the haemodynamic effects, the patients' sensations, signs of thrombophlebitis and postoperative nausea and vomiting (PONV) following injection of both drugs. ⋯ Etomidate formulated in a medium chain lipid emulsion causes significant less discomfort for the patients than propofol, which is solved in a long chain formulation. Myocloni, however, occur significantly more frequently after etomidate than after propofol.
-
Randomized Controlled Trial Clinical Trial
[The effect of nitroglycerin on cerebrovascular circulation, cerebrovascular CO2-reactivity and blood flow rate in basal cerebral arteries].
The cerebral haemodynamic effects of vasodilators are of clinical interest because a decrease in mean arterial pressure (MAP) might alter global cerebral blood flow (CBF). Luxury perfusion of the brain, contrast, might be unfavourable in patients with reduced intracranial compliance. Despite the widespread use of nitroglycerine (NTG), little is known about the cerebral haemodynamic consequence of NTG infusions in humans. This prospective, controlled study was designed: (1) to investigate the effects of NTG on CBF and cerebrovascular CO2 reactivity and (2) to compare reference measurements of global CBF with transcranial Doppler monitoring (TCD) of middle cerebral artery flow velocity (VMCA). ⋯ This study demonstrates that during fentanyl/midazolam anaesthesia NTG may cause a major increase in CBF as long as CPP does not decrease considerably. Our results further suggest that NTG causes vasodilation of basal cerebral arteries, inducing a discrepancy between relative changes in CBF and VMCA. Consequently, TCD measurements during infusion of NTG should not be directly compared with preceding measurements of MCA flow velocity.