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Biomedical subjects

R F Morawetz

Publications and source records attributed to R F Morawetz.

9 recordsLinked to original sources
PubMed1991

[Impairment of the cognitive faculties and the reaction capability caused by midazolam despite reversal using flumazenil].

Imidazobenzodiazepine (flumazenil) is a specific competitive benzodiazepine antagonist. It antagonizes the sedative-hypnotic, anticonvulsive, anxiolytic and the muscle-relaxant effects of benzodiazepines. Its efficacy is prompt and complete. In several studies rebound phenomena have been observed. It was the aim of this randomized double blind study to investigate the efficacy of flumazenil by psychometric tests. The psychometric parameters we used were cognition and choice reaction time of 12 young and healthy volunteers. Three medication groups (A, B and C) were formed for this investigation. In a cross over design all volunteers had to be treated in each of these three medication groups. Between the groups we set a test-free interval of 7 days for every volunteer. In medication group A (midazolam/flumazenil) we applied 15 mg midazolam. Reversion was performed after 60 min with 0.5 mg flumazenil. In medication group B (placebo/flumazenil) midazolam was replaced by a physiological solution of sodium chloride. In medication group C (placebo/placebo) midazolam and flumazenil were substituted by a physiological solution of sodium chloride. For the investigation of the psychometric parameters (cognition and choice reaction time) we used the so called syndrome kurz test (SKT) and the decision reaction time measuring instrument ("Entscheidungs-Reaktionszeit-Messgerät"; ERM). Psychometric investigations were performed in all groups at intervals of 5, 30, 60, 90, 120, 180 and 240 min. Our results show that cognitive abilities remain impaired up to 60 min after the administration of flumazenil. Decision time and choice reaction time improved 120 min after administration of the antagonist. In our investigation neither rebound phenomena nor agonistic reactions of flumazenil were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Additional subcutaneous administration of flumazenil does not shorten recovery time after midazolam.

We assessed the efficacy of subcutaneous administration of flumazenil (Anexate, Roche), a specific benzodiazepine antagonist, in preventing resedation after initial reversal of midazolam sedation in 30 patients (ASA I-II) undergoing gynaecological surgery. In the post-operative period, the patients received flumazenil i.v. and placebo s.c. (group A), flumazenil i.v. and flumazenil s.c. (group B), or placebo i.v. and placebo s.c. (control group) in a randomized, double-blind procedure. Flumazenil (group A: 0.47 (SD 0.12) mg i.v., group B: 0.48 (0.06) mg i.v.) was significantly more effective than placebo in antagonizing the sedative effects of midazolam, but was accompanied by rebound sedation after 90 min. Additional s.c. administration of flumazenil 0.1 mg (group B) did not eliminate resedation. Undesirable side effects include nausea and vomiting. Local tolerance of the subcutaneous administration of flumazenil was good.

Adult↗
PubMed1990

[Weaning an asthmatic using biphasic positive airway pressure together with continuous sufentanil administration].

A patient presenting with acute severe asthma associated with protracted hypoventilation (paCO2 = 90 mmHg) and impaired consciousness underwent sedation and controlled mechanical ventilation. The peak airway pressure could be reduced by constant-volume mechanical ventilation and analgosedation with midazolam and ketamine. When the gas exchange had stabilized, the first attempt at weaning was made by synchronized intermittent mechanical ventilation (SIMV). After this and two other attempts had failed, the patient was given continuous sufentanil (0.8-1.0 micrograms/kg), as well as additional bolus injections of 2 micrograms/kg and 0.35 micrograms/kg for analgosedation. Controlled mechanical ventilation was replaced by the system of biphasic positive airway pressure (BIPAP). The mechanical ventilatory support was gradually reduced, as was the dose of continuous sufentanil. Extubation was possible at a dose of 0.2 micrograms/kg per h sufentanil and CPAP. From this case, it is not possible to determine whether the BIPAP system or the analgosedation with Sufentanil was the decisive factor in the therapeutic success. It may well have been the combination of both therapeutic measures that--in our opinion--supplemented each other in an ideal way.

Fentanyl↗
PubMed1990

[The multidisciplinary outpatient pain clinic in relation to anesthesia. An important task for the anesthesiologist].

Anesthesiologists have always played a leading role in research into pain and its treatment. Their efforts, however, have been focused on acute or postoperative pain problems. It was the American anesthesiologist John J. Bonica who fought for an increased interest in chronic pain. The establishment of the first Multidisciplinary Pain Center at the University of Washington in Seattle, the foundation of the International Association for the Study of Pain (IASP) and Melzack and Wall's now 25 year old gate control theory were the driving forces behind rapid developments in research and treatment in the area of chronic pain. The realization that chronic pain was the most frequent cause of disability in the United States also gave an impetus for new efforts in treatment. The classic anesthesiological topics, such as operative anesthesia emergency medicine and intensive care, have been extended to include acute pain services and chronic pain treatment facilities. This reflects the understanding that anesthesiological knowledge and techniques can be valuable to patients in severe acute pain and those in lingering long-term chronic pain phases. Anesthesiologists are skilled in the use of opioid narcotics and in the administration of strong analgesics. Many severe pain problems can be solved by correct use of the analgesic regimen. Special ways of administering narcotic analgesics, such as epidural infusion or patient-controlled analgesia, have already alleviated the pain problems of many patients. Anesthesiological techniques are also crucial in diagnosis. Sequential differential blockade and simple nerve blocks can be helpful in the diagnosis and classification of the pain problems. Anesthesiological contributions to a chronic pain service are not restricted to medical interventions. Organizational skills are also needed for efficient running of multidisciplinary pain treatment facilities. Clinical practice in surgical anesthesia means that anesthesiologists are experienced in interdisciplinary work and familiar with the advantages and dangers of team work. Despite international acceptance of the multidisciplinary approach to chronic pain, there is still a lack of appropriate facilities in the German-speaking countries, and we consider it important that anesthesiologists commit themselves to increasing general awareness of what is needed.

Ambulatory Care Facilities↗
PubMed1990

[Nalbuphine as compared with pethidine for postoperative pain therapy].

Nalbuphine is a new partly agonistic antagonistic opioid, that may offer some advantages especially in postoperative pain relief. We compared meperidine (1 mg kg-1) in 100 patients and nalbuphine (0.3 mg kg-1) in 70 patients, administering both agents intravenously after gynaecological operations. Standardised halothane anaesthesia without any opioid was used. After arrival in the recovery room, vigilance (sedation), quality and duration of pain relief were measured by different methods at four different times (0, 15, 30, and 60 minutes). Sedation was significantly more pronounced in the nalbuphine group, but no difference could be found in pain relief and duration between both groups. 6 patients of the n-group showed a short lasting wake-up reaction due to receptor antagonism. 36 patients had to be reinjected at the end of the first hour. We consider nalbuphine to be a safe opioid, however, the marked sedation should be taken into account.

Adult↗
PubMed1984

[Characterization of the effect of analgesics on the assessment of experimental pain in man. Pethidine and tramadol in a double-blind comparison].

The effect of the opioid analgesics tramadol and pethidine on experimentally induced pain was investigated in a double blind study with healthy volunteers. Using a constant current shocker, compensating the changes of the skin resistance, a constantly increasing pain stimulus was produced. Detection-, pain-, and tolerance-thresholds were assessed before and three times after intravenous injection of either pethidine (1 mg/kg bodyweight), tramadol (2 mg/kg bodyweight) or placebo (NaCl). While the two analgesics caused an increase of all three thresholds the placebo did not cause any threshold changes. The rise of the detection threshold after application of tramadol and pethidine suggests a sedation effect. However, in relation to the analgesic effect this sedation effect is stronger with tramadol than with pethidine. With the dosage used in this experiment, there is no difference in the analgesic effect of tramadol and pethidine. Compensating for intra- and interindividual changes in skin resistance, the pain stimulation method used in this study provides a good quantification of the effects of analgesics.

Adult↗