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Biomedical subjects

M Zenz

Publications and source records attributed to M Zenz.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Anesthesia and intensive care management of severely burned children of Jehovah's Witnesses].

A 3.5-year-old girl suffered from a thermal injury affecting 37% of the body surface area. The parents, being Jehovah's witnesses, refused permission for their child to receive blood transfusions. As the haemoglobin level was only 7.5% and a necrectomy was planned, the patient was likely to need blood transfusions. Indications for transfusion were defined as clinical signs of hypoxia and/or cardiovascular instability. A judicial declaration was proposed. Hb decreased during the therapy. To stimulate the erythropoiesis erythropoietin and iron were administered. During the clinical course the anaemia worsened. First, a conservative treatment with polyvidoniodine ointment for tanning was started, to avoid an operation during the acute phase after the injury, as in this case it was thought a blood transfusion would definitely be necessary. On the 19th day after the injury a necrectomy of 10% of the body surface was necessary because of fever and leucocytosis not responding to antibiotics. The most likely cause of the symptoms was an infection of the burned area. Hb was 4.6 g/dl%. General anaesthesia was performed with midazolam, ketamine and vecuronium and mechanical ventilation. No blood transfusion was required during the operation. Vital signs were stable during the preoperative period, during anaesthesia and following the operation. There were no signs of tissue hypoxia. Peripheral oxygen saturation ranged between 98% and 100%, lactate and arterial blood gas samples were normal, and the child was awake and cooperative before and after anaesthesia. The lowest Hb was 3.3 g/dl on the 22th day after injury (3rd postoperative day). In this phase the patient was still playing and riding a tricycle. On the 45th day after injury the child was discharged home with Hb of 10.9 g/dl and reticulocytosis of 33%.

Anemia↗
PubMed1996

[Oral opioids for long-term treatment of chronic non-cancer pain].

The treatment of cancer pain with opioids is well accepted. However, the use of opioids for the treatment of non-cancer pain is still a matter of controversy. The main matters of concern are physical dependence and opioid abuse. Another argument against opioids is the lack of efficacy. Experiences with opioids in non-cancer pain have been published on about 850 patients, the longest therapy lasting almost 14 years. 85% of the patients treated with opioids had beneficial effects. In a number of investigations evaluating the opioid sensibility of pain by PCA and intravenous infusions, 67-80% of the patients with neuropathic pain responded to opioids. The efficacy of opioids in the treatment of non-cancer pain was proven in 3 placebo controlled studies. In 2 studies pain reduction in neuropathic pain was similar to that in nociceptive pain. When opioids are used, the administration has to be performed according to well defined standards. The indication for opioids must be made by a specialist in pain management. The diagnosis must clearly reveal an organic origin of the pain. Before the start of therapy the duration as well as the criteria for discontinuation must be set up. The treatment must be controlled by a specialist team and frequent regular follow up investigations must be performed. These must include proper documentation of the pain level, changes in patients' function and in social activities. The reliable intake of prescribed medication must be assured if necessary by laboratory screening. The treatment of non-cancer pain with opioids may be an alternative for those patients, who didn't gain sufficient reduction of pain by other therapies. Standards for this therapy are an absolute necessity and are to be followed closely.

Analgesics, Opioid↗
PubMed1996

Preoperative alpha2-adrenergic receptor agonists prevent the deterioration of renal function after cardiac surgery: results of a randomized, controlled trial.

OBJECTIVE: To evaluate the influence of the alpha2-adrenergic receptor agonist clonidine on creatinine clearance as a measure of renal function. DESIGN: Prospective, double-blind, randomized, placebo-controlled clinical trial. SETTING: University hospital. PATIENTS: Patients undergoing coronary artery bypass graft surgery (n = 48) with normal risk. INTERVENTIONS: Administration of clonidine (4 micrograms/kg iv)) or placebo 1 hr before induction of anesthesia. MEASUREMENTS AND MAIN RESULTS: Induction and maintenance of anesthesia (etomidate, midazolam, and fentanyl) and cardiopulmonary bypass technique (nonpulsatile, normothermic, intermittent cold blood cardioplegia) were standardized in all patients. The night before surgery and the first and third night after surgery, creatinine clearance was calculated from a 12-hr urine collection period. Venous blood samples for determination of plasma antidiuretic hormone (ADH) concentrations were taken the evening before surgery, immediately before induction of anesthesia and the evening after surgery (n = 16). Arterial catecholamine plasma concentrations were determined (high-performance liquid chromatography) before induction, 15 mins after induction of anesthesia, immediately after sternotomy, before initiation of cardiopulmonary bypass, as well as 5, 15, and 30 mins after initiation of cardiopulmonary bypass (n = 16). The total amount of anesthetics, infusions, transfusions, diuresis, and blood loss was not different between the groups. Creatinine clearance decreased over the first postoperative night from 98 +/- 18 (preoperatively) to 68 +/- 19 mL/min (p < .05) in placebo-treated patients. Creatinine clearance remained unchanged in clonidine-treated patients (90 +/- 19 [preoperatively] to 92 +/- 17 mL/min). There was a significant difference in creatinine clearance between the groups during the first postoperative night (p < .05; Mann-Whitney U test). In the third postoperative night, mean creatinine clearance of both groups was not different (75 +/- 31 vs. 86 +/- 28 mL/min). ADH concentrations were not different between the groups at any time, while plasma catecholamine concentrations were always significantly lower in clonidine-treated patients. CONCLUSIONS: Preoperative treatment with clonidine (4 microgram/kilogram) prevents the deterioration of renal function after cardiac surgery. This effect might be due to clonidine-induced reduction in the sympathetic nervous system response to coronary artery bypass graft surgery.

Adrenergic alpha-Agonists↗
PubMed1995

Sympathetic skin response in patients with reflex sympathetic dystrophy.

The sympathetic skin response (SSR) originates from synchronized activation of the sweat glands as a response to a volley discharge in efferent sympathetic nerve fibres. The aim of the study was to verify the diagnostic value of SSR in patients with reflex sympathetic dystrophy (RSD). SSR was recorded in 20 normal subjects and in 24 patients with predominantly chronic RSD. In normal subjects inter- and intra-individually different mono-, bi- and triphasic potentials could be recorded without difference of the waveform from side to side. SSR abnormalities were found in 15 patients and correlated with the severity of the disease. In patients with slight dystrophies, SSR was predominantly normal. In intermediate dystrophies, mainly differences of the SSR waveform between sides could be recorded, indicating unilateral sudomotor dysfunction. In severe dystrophies abnormalities of SSR amplitude or latency were found, indicating more serious disturbance of sudomotor activity, possibly due to a lesion of sympathetic fibres. The SSR provides useful information on sudomotor dysfunction in patients with RSD. However, as there is no consensus in the literature for the clinical criteria to diagnose RSD, it is not yet possible to determine the final diagnostic value of SSR for the diagnoses of RSD.

Adult↗
PubMed1995

Severe undertreatment of cancer pain: a 3-year survey of the German situation.

The aim of this survey was to determine the prescribing patterns of German physicians in the treatment of cancer pain. The computerized patient records of 330 practices, which treated a total number of 1,104,435 patients over a 3-year period, were analyzed. "Strong" opioids, widely accepted in the management of severe cancer pain, were prescribed to just 322 of 16,630 cancer patients (1.9%). Only 99 (0.6%) patients received more than three prescriptions during more than 3 weeks of treatment. Additionally, many prescriptions mandated inadequate time intervals for the dosing, and 12% of the prescriptions were given "as required." From these data, it can be concluded that the majority of cancer patients in Germany are not treated for pain at all, and that those patients who receive treatment are treated inadequately. Germany is still a developing country in terms of pain therapy. This situation is symptomatic of many countries and reflects the continuing prejudice against opioids.

Analgesics, Opioid↗
PubMed1995

Dose-response effects of intravenous clonidine on stress response during induction of anesthesia in coronary artery bypass graft patients.

This study was designed to evaluate the dose-response effects of different doses of clonidine on the stress response to laryngoscopy and endotracheal intubation. In a randomized, double-blind study, 48 coronary artery bypass grafting (CABG) patients received 0, 2, 4, or 6 micrograms/kg clonidine as an intravenous (IV) infusion during a 15-min period 30 min prior to induction of anesthesia with etomidate (0.3 mg/kg), fentanyl (5-7 micrograms/kg), and pancuronium (0.1 mg/kg). Sedation was assessed prior to induction of anesthesia. Cardiovascular variables and catecholamine plasma levels were measured at predefined intervals. Additional bolus doses of etomidate and fentanyl for suppression of stress-induced reactions were administered if predefined limits of heart rate and blood pressure were exceeded. Clonidine 4 and 6 micrograms/kg significantly attenuated hemodynamic and adrenergic reactions to stress, reduced pharmacologic interventions, and increased sedation. However, clonidine 6 micrograms/kg was not more effective than 4 micrograms/kg, and clonidine 2 micrograms/kg was equally effective as placebo. We conclude that clonidine 4 micrograms/kg IV is the appropriate dose to attenuate the stress response to laryngoscopy in CABG patients. Side effects limiting the use of IV clonidine were not observed.

Blood Pressure↗
PubMed1995

Transdermal fentanyl: a new step on the therapeutic ladder.

The high efficacy, low molecular weight and high lipid solubility of fentanyl make it a suitable agent for transdermal administration. Effective plasma concentrations are maintained for up to 48-72 hours after application of a transdermal therapeutic system (TTS) fentanyl patch. In a multicentre study, slow-release morphine was replaced by TTS fentanyl according to a special calculation table (10 mg oral morphine corresponding to approximately 0.1 mg TTS fentanyl). Ninety-eight patients were included in the study. Due to protocol infringements, however, the switch from oral morphine to TTS fentanyl could be assessed for only 38 patients. The changeover at a ratio of 100:1 proved to be safe and effective and a good alternative therapy to conventional strong opioids. The majority of the patients wished to continue TTS fentanyl therapy at the end of the study period. Side effects were similar to those associated with other opioids. However, TTS fentanyl was associated with a distinct decrease in constipation and a significant reduction in the use of laxatives. Furthermore, there were some indications that compliance may be increased with TTS fentanyl. Special indications for chronic pain therapy using transdermal opioids include head and neck and gastro-intestinal tract cancer. In these cases, TTS fentanyl may be the final non-invasive form of analgesic therapy which allows the patient to maintain a normal lifestyle. TTS fentanyl thus represents a new alternative for therapy with strong opioids on step III of the World Health Organization analgesic ladder.

Administration, Cutaneous↗
PubMed1994

Rapid-sequence orotracheal intubation with rocuronium: a randomized double-blind comparison with suxamethonium--preliminary communication.

Eighty ASA I-III patients were randomly assigned to four groups. Group I patients received rocuronium 0.6 mg kg-1 immediately prior to thiopentone, while patients in group II received the same dose immediately after the induction agent. In groups III and IV a priming dose of rocuronium 0.04 mg kg-1 was administered prior to induction. Group III patients received rocuronium immediately prior to thiopentone. In group IV, suxamethonium 1.5 mg kg-1 was administered immediately after thiopentone. Intubation conditions were scored by a blinded investigator. An intubation time of > 60 s was defined as a failure. All patients could be intubated within 60 s. Priming with rocuronium did not improve intubation conditions. Total intubation scores > 6 occurred significantly more often in group II (P < 0.01 vs. all other groups). A single bolus dose of rocuronium 0.6 mg kg-1 (2 x ED95) administered immediately prior to thiopentone 6 mg kg-1 offers the same intubation conditions as suxamethonium 1.5 mg kg-1.

Adult↗
PubMed1993

[Does clonidine modify the hypnotic effect of propofol?].

The administration of alpha 2-adrenoceptor agonists before the induction of anaesthesia leads to a significant reduction in the amount of anaesthetic medication required, probably due to an attenuation of haemodynamic stress responses in centrally mediated sympathicolysis. However, it is not yet known whether alpha 2-adrenoceptor agonists influence the hypnotic action of anaesthetics. Therefore, this study was performed to evaluate the influence of the alpha 2-adrenoceptor agonist clonidine on the potency and the duration of the hypnotic action of anaesthetic agents. METHOD. The study was approved by the local ethical committee. To study the effect of clonidine on the potency of propofol we determined the ED50 of propofol with and without clonidine pretreatment. To this end, 100 unpremedicated patients (ASA I or II) were randomly assigned to receive 4 micrograms/kg body weight clonidine or placebo, each of which was dissolved in 100 ml NaCl and infused over a period of 15 min starting 30 min before the induction of anaesthesia. According to the results of a pilot study, patients who had been treated with clonidine received either 0.25, 0.5, 0.75, 1 or 1.25 mg/kg propofol for anaesthesia induction. Patients in the placebo group received 0.5, 1, 1.5, 2 or 2.5 mg/kg propofol. The success of anaesthesia induction was evaluated clinically (eye opening on command, eyelid reflex). On the basis of these data the ED50 of propofol with and without clonidine pretreatment was calculated using the modified probit analysis according to Spearman and Kärber. The effect of clonidine on the duration of anaesthesia was compared in six groups of 10 patients each, who received 1, 1.5 or 2 mg/kg propofol for anaesthesia induction with and without prior clonidine treatment. RESULTS. In the placebo group a dose of 0.5 mg propofol per kg did not produce a hypnotic effect in any patient, while 2.5 mg propofol per kilogram of body weight was effective in all patients. In the clonidine group 0.25 mg propofol per kilogram of body weight had no hypnotic effect, while 1.25 mg propofol per kilogram of body weight was effective in all patients. Increasing the dose of propofol resulted in an increasing number of successful anaesthesia inductions in the placebo as well as in the clonidine group. According to these data, the ED50 of propofol with clonidine was calculated at 0.675 +/- 0.23 mg/kg with clonidine and 1.5 +/- 0.58 mg/kg without clonidine pretreatment. Increasing the dose of propofol did not result in a significant increase in the duration of anaesthesia (1 mg/kg: 260 +/- 114 s; 1.5 mg/kg: 270 +/- 103 s; 2 mg/kg: 295 +/- 152 s). However, premedication with clonidine almost doubled the duration of the hypnotic action of propofol (1 mg/kg: 457 +/- 239 s; 1.5 mg/kg: 501 +/- 249 s; 2 mg/kg: 582 +/- 254 s) (P < 0.01). CONCLUSION. According to these findings the administration of clonidine prior to anaesthesia induction significantly increases the potency and the duration of the hypnotic action of propofol. From our data we conclude that the influence of clonidine on the hypnotic action of anaesthetics is an important factor in the reduction of anaesthetic requirements observed after clonidine pretreatment.

Adrenergic alpha-Agonists↗
PubMed1993

[Fentanyl-TTS for postoperative pain therapy. A new alternative?].

Treatment of postoperative pain is often insufficient. It normally consists of systemic application of an analgesic drug or a regional technique of analgesia. Fentanyl-TTS may be a new approach for postoperative pain therapy. Fentanyl is incorporated into a transdermal system; after application to the skin continuous release of therapeutic doses is achieved for a period of 72 h. Serum peak levels are obtained 8-16 h after application; the serum half-life is about 16-21 h because of the dermal depot. Fentanyl-TTS was administered in several clinical studies for therapy of postoperative pain. The efficacy of this new form of application could be demonstrated. For the first 12 h the patients needed supplementary doses of analgesic drugs in the same range as the placebo groups because of the lag time of fentanyl-TTS. In the following 12 h the need for supplementary analgesics was significantly reduced. After removal of the patch, the need for analgesics was still reduced for 12 h. In 21 of 341 patients respiratory depression occurred under therapy with fentanyl-TTS; no respiratory depression was observed in the placebo groups. Thus, respiratory depression might occur in up to 9% of postoperative patients treated with fentanyl-TTS. Other adverse effects were nausea (62%), vomiting (26%), sedation (22%), urinary retention (11%), headache (5%), and dizziness (8%). Local reactions under the patch were erythema (39%) or pruritus (9%). These phenomena disappeared within a few hours. The pharmacokinetics of fentanyl-TTS have two major drawbacks: during the first 12-15 h the patients need supplementary analgesics, usually opioids.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗