[The effect of HES, dextran and gelatin on kidney function].
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to M Georgieff.
Explore the source record for details and available documents.
OBJECTIVE: Although an increasing number of studies concerning postoperative nausea and vomiting (PONV) have been performed, we do not know, what anaesthesiologists think about this problem and how they handle it in their daily routine. METHODS: A survey was performed involving anesthesiologists at 30 institutions of different size. 474 out of 1000 questionnaires were returned. RESULTS: When asked what kind of general anaesthesia they prefere in a woman at a very high risk to suffer PONV, the following answers were obtained: anaesthesia induction with propofol (78%), thiopentone (17%), etomidate (5%). Maintenance of anaesthesia with an inhalation anesthetic (44%) or with propofol (44%). The remaining 14% would use a combination of these techniques (6%) or neuroleptanaesthesia with droperidol (5%) or midazolam (1%). Only 10% of the respondants would omit nitrous oxide. There is no consensus about the optimal amount of intraoperative opioids. Fentanyl, alfentanil, and sufentanil are rated to contribute equally to the occurence of PONV, whereas opioids used for postoperative analgesia are thought to have substantial differences: piritramid is rated to be much less emetogenic than tramadol and morphine. 70% advocate routine antiemetic prophylaxis for high-risk patients (most often mentioned risk factors were: female sex: 85%, obesity: 81%, high doses of intraoperative opioids: 72%) and 23% administrate antiemetics even for all patients. Ondansetron and droperidol are suggested to be superior to metoclopramide, triflupromazine, dimenhydrinate, and transdermal scopolamine. However, metoclopramide is the drug of first choice for more than 50% of the respondants followed by droperidol, whereas only 29% use ondansetron as a first line drug. An unexpected high number of anaesthesiologists (13%) have experience with non-pharmacological methods for prophylaxis and treatment of PONV. Acupuncture/acupressure (10%) was most often mentioned. CONCLUSION: A great majority (93%) stated, that PONV is a relevant problem, that still remains unsolved. This proofs the need for further controlled studies.
A methylchloroformate derivative was used for the simultaneous determination of plasma enrichments of 1-13C-phenylalanine, 1-13C-tyrosine, 15N-phenylalanine and 15N-tyrosine by gas chromatography/mass spectrometry. All four tracer enrichments could be measured in a single GC run. A specific ion fragment was obtained for each tracer. This approach allowed an easy determination of the "tracer to tracee ratios". Each ion fragment could be measured with an appropriate single-to-noise ratio and precision in samples obtained from 100 microliters plasma. The derivatization consists of a fast one-step reaction. Therefore it is well suited for studies involving a large number of samples, such as non-steady state bolus studies.
We studied 30 male patients in the early postoperative period to assess the efficacy, safety and feasibility of a patient-demand, target-controlled infusion (TCI) of remifentanil. All patients received the same TCI-based propofol-remifentanil anaesthetic for elective orthopaedic surgery. At the end of surgery, infusion of remifentanil was reduced progressively until patients were breathing spontaneously. After extubation and transfer to the post-anaesthesia care unit, patients were given control of a hand-set and were able to increase the target remifentanil blood concentration by increments of 0.2 ng ml-1. If there were no demands, the TCI controller automatically reduced the target concentration. Pain scores, sedation level, ventilatory frequency, oxygen saturation and nausea were assessed. Mean time to onset of satisfactory analgesia (VAS < or = 3, out of 10) was 18.9 (95% confidence interval (Cl) 15.8-21.9) min at a mean target remifentanil concentration of 2.02 (Cl 1.87-2.16) ng ml-1. There were no episodes of hypoxaemia and the lowest ventilatory frequency was 9 bpm. Nausea occurred in 26.6% of patients and 10% vomited. The majority of patients were only slightly sedated. These results imply an effective tool without respiratory side effects in the early postoperative period after anaesthesia using remifentanil as the analgesic component.
UNLABELLED: The context-sensitive half-time, the time required for a 50% decrease in drug concentration, has been proposed to predict the speed of recovery after infusions of i.v. anesthetics. We studied 40 patients to compare the clinical recovery characteristics of alfentanil and sufentanil. Patients were randomly allocated to receive either sufentanil/propofol (Group 1) or alfentanil/propofol (Group 2) total i.v. anesthesia by target-controlled infusions (TCI), assuming an equipotency ratio of 500:1. After discontinuation, times to tracheal extubation and to discharge from the postanesthesia care unit were measured, as were drug concentrations up to 24 h. The TCI bias was -17.1% for sufentanil and -16.9% for alfentanil. We found no difference in mean extubation times between the groups (48.7 min in Group 1 versus 46.4 min in Group 2), whereas discharge criteria were fulfilled significantly (P = 0.039) earlier after alfentanil (99.5 min) compared with sufentanil (131.3 min). The relative decrement values to tracheal extubation were 62.1% for sufentanil and 48.0% for alfentanil, compared with 75.7% and 65.0% for discharge, respectively. Based on a difference in propofol requirements, we suggest an actual sufentanil to alfentanil equipotency ratio of 1:300. We conclude that the decay in pharmacodynamic effect is not only the result of pharmacokinetics. IMPLICATIONS: Computer simulations may help to anticipate the clinical behavior of anesthetic drugs. In a clinical setting, we tested whether the recovery characteristics after i.v. anesthesia could be explained by a pharmaco-kinetic value, which describes the decline of drug concentrations in the body. This was not fully achieved.
UNLABELLED: None of the natural and synthetic colloids currently available is free from the risk of side effects. This study was performed to contribute to the epidemiology of adverse reactions of the widely used 200/0.5 hydroxyethyl starch 6% solution (HES). Study end points were anaphylactoid reactions during preanesthesia infusion and perioperative course, and pruritus 5 days postoperatively (clinical examination and inquiry) and 8 wk after application (mailed patient questionnaire). We consecutively randomized 750 patients undergoing minor elective surgery into two parallel groups treated with HES (from two different manufacturers) and one control group treated with lactated Ringer's solution. The study population was well matched among the groups and consisted of patients of both sexes, aged 18-95 yr, ASA physical status I-III. No drug-related anaphylactoid reactions were detected during either of the observation intervals. There was no episode of pruritus after the fifth postoperative day. Incidence of pruritus after 8 wk was quite frequent but not significantly different (chi2 test, P = 0.77): 9.1% and 12.0% in the two HES groups and 11.5% in the lactated Ringer's solution control group. Except for pruritus, we conclude that HES was associated with no more complications than lactated Ringer's solution. IMPLICATIONS: Anaphylactoid reactions and pruritus (itching) after the administration of a 6% hydroxyethyl starch (200/0.5) versus lactated Ringer's solution were assessed in a prospective, randomized, controlled study. There were no differences, although there was a more than 10% incidence of pruritus in both groups.
BACKGROUND: The incidence of perioperative bradyarrhythmias in patients with bifascicular or left bundle branch block (LBBB) and the influence of an additional first-degree atrioventricular (A-V) block has not been evaluated with 24-h Holter electrocardiographic monitoring. Therefore the authors assessed the rate of block progression and bradyarrhythmia in these patients. METHODS: Patients (n = 106) with asymptomatic bifascicular block or LBBB with or without an additional first-degree A-V block scheduled for surgery under general or regional anesthesia were enrolled prospectively. Three patients were excluded. Of the 103 remaining, 56 had a normal P-R interval and 47 had a prolonged one. Holter monitoring (CM2, CM5) was applied to each patient just before induction of anesthesia and was performed for 24 h. The primary endpoint of the study was the occurrence of block progression. As secondary endpoints, bradycardias < 40 beats/min with hemodynamic compromise (systolic blood pressure < 90 mmHg) or asystoles > 5 s were defined. RESULTS: Block progression to second-degree A-V block and consecutive cardiac arrest occurred in one case of LBBB without a prolonged P-R interval Severe bradyarrhythmias with hypotension developed in another eight patients: asystoles > 5 s occurred in two cases and six patients had bradycardias < 40/min. Pharmacotherapy was successful in these eight patients. There was no significant difference for severe bradyarrhythmias associated with hemodynamic compromise between patients with and without P-R prolongation (P = 1.00). CONCLUSIONS: In patients with chronic bifascicular block or LBBB, perioperative progression to complete heart block is rare. However, the rate of bradyarrhythmias with hemodynamic compromise proved to be relevant. Because an additional first-degree A-V block did not increase the incidence of severe bradyarrhythmias and pharmacotherapy by itself was successful in nearly all cases, routine prophylactic insertion of a temporary pacemaker in such patients should be questioned.
BACKGROUND: Clinical interest in xenon has been rekindled recently by new recycling systems that have decreased its relative cost. The cardiovascular effects of xenon were examined in isoflurane-anesthetized dogs before and after the development of rapid left ventricular (LV) pacing-induced cardiomyopathy. METHODS: Dogs (n = 10) were chronically instrumented to measure aortic and LV pressure, LV subendocardial segment length, and aortic blood flow. Hemodynamics were recorded, and indices of LV systolic and diastolic function and afterload were determined in the conscious state and during 1.5 minimum alveolar concentration isoflurane anesthesia alone and combined with 0.25, 0.42, and 0.55 minimum alveolar concentration xenon in dogs with and without cardiomyopathy. RESULTS: Administration of xenon to healthy dogs anesthetized with isoflurane decreased heart rate and increased the time constant (tau) of isovolumic relaxation but did not alter arterial and LV pressures, preload recruitable stroke work slope, and indices of LV afterload. Chronic rapid LV pacing increased the baseline heart rate and LV end-diastolic pressure, decreased arterial and LV systolic pressures, and produced LV systolic and diastolic dysfunction. Administration of xenon to isoflurane-anesthetized, cardiomyopathic dogs did not alter heart rate, arterial and LV pressures, myocardial contractility, and indices of early LV filling and regional chamber stiffness. More pronounced increases in tau were accompanied by increases in total arterial resistance during administration of xenon to isoflurane-anesthetized cardiomyopathic compared with healthy dogs. CONCLUSIONS: The results indicate that xenon produces minimal cardiovascular actions in the presence of isoflurane in dogs with and without experimental dilated cardiomyopathy.
Explore the source record for details and available documents.
OBJECTIVE: To evaluate the long-term effects of lactic acidosis and to examine a potential neuroprotective role of basic fibroblast growth factor (bFGF) on hippocampal neurons. DESIGN: Long-term observation in a cell-culture study. SETTING: University research laboratory. SUBJECTS: Adult, differentiated, primary rat hippocampal neurons. INTERVENTIONS: Neurons were exposed to medium acidified with 20 mM lactic acid, pH 6.2, for a 10-min period, and maintained untreated or in the presence of bFGF (500 pg/mL, 1 ng/mL, 10 ng/mL, 20 ng/mL) applied after exposure. MEASUREMENTS AND MAIN RESULTS: Viability was analyzed by a dye inclusion/enzyme activity test and morphology by phase contrast and immunofluorescence microscopy. [3H]Arachidonic acid (AA) release was measured by liquid scintillation spectrometry. All cultures appeared to be unchanged during the first days after exposure to lactic acidosis. Neurodegeneration became apparent within 3 days. Seven days after exposure, cell survival decreased to 60% in lactic acidosis-injured, untreated cultures. Morphologic damage appeared as a 50% reduction in axonal and 25% reduction in dendritic arborizations. AA release increased to four-fold enhanced levels relative to control values. bFGF (1, 20, and 10 ng/ mL) enhanced neuronal viability (p < .05), and 10 ng/mL bFGF induced a maximal increase in live cells to 80% of controls. Axonal arborizations increased to 50% and dendritic arborizations to 75% of controls after 10 ng/mL bFGF (p< .05). bFGF in a dose of 20 ng/ mL enhanced axonal branching to 40% and dendrites in number and branching to 50% of controls (p< .05). bFGF (500 pg/mL, and 1 and 10 ng/mL) decreased enhanced AA (p < .05), and 10 ng/mL bFGF maximally reduced increased AA to two-fold enhanced values relative to controls. CONCLUSIONS: In vulnerable neurons, exposure to moderate lactic acidosis induces a process of cell injury with long latency. bFGF applied postinjury reduces the delayed neurodegeneration and may have neuroprotective efficacy in new therapeutic strategies to ischemia-induced cerebral injury.
BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors are well established as long-term antihypertensives and have also been proved useful in hypertensive emergencies. Therefore, we investigated whether intraoperative i.v. enalaprilat may reduce the incidence of perioperative hypertensive reactions in coronary artery bypass grafting (CABG). METHODS: Thirty-eight male patients chronically treated for arterial hypertension and scheduled for CABG randomly and double-blindly received either enalaprilat 30 micrograms.kg-1 or NaCl 0.9% at the time of skin incision. Intraoperatively, increases of mean arterial pressure (MAP) > 85 mmHg or > 80 mmHg during cardiopulmonary bypass (CPB) were treated by an urapidil bolus. The total intraoperative amount of urapidil was documented for both groups. Systemic and pulmonary hemodynamics as well as the plasma levels of epinephrine, norepinephrine, arginine vasopressin and renin were measured intraoperatively and up to 2 h after admission to the intensive care unit. RESULTS: Mean arterial pressure, cardiac index and systemic vascular resistance did not differ between the enalaprilat and the control group. Renin plasma levels significantly increased after infusion of enalaprilat and did not change in the placebo group. Catecholamine and arginine vasopressin plasma levels increased significantly during CPB and remained high in the postoperative period without any intergroup difference. The same amount of urapidil had to be given in the two groups to maintain MAP below the defined limit. CONCLUSION: We conclude that infusing 30 micrograms.kg-1 enalaprilat in patients chronically treated for arterial hypertension does not prevent hypertensive reactions during CABG.
BACKGROUND: We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI2) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. METHODS: In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGF1 alpha (stabile metabolite of PGI2), TXB2 (stabile metabolite of thromboxane A2) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. RESULTS: Following MT, arterial hypotension occurred along with a substantial PGI2 release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF1 alpha (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P = 0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB2 (164 (87) vs. 58 (1) ng/L, P = 0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P = 0.001), AVP (41 +/- (18) vs. 12 (7) ng/L, P = 0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. CONCLUSION: Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI2 release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A2, presumably contributing to hemodynamic stability within 30 min after MT.
Critically ill patients with systemic inflammatory response syndrome (SIRS) and multi-organ failure are at great risk of nosocomial infections due to a reduced immune status. There is growing evidence from in vitro studies and animal models that the reduced immune response might be improved by the so-called immunomodulatory nutrition. Based on these studies there are now some commercially available enteral or parenteral solutions with immunomodulatory substrates, such as n-3 polyunsaturated fatty acids (PUFAs), arginine and nucleotides. Recently, enteral nutrition with this experimental formula reduced the hospital length of stay and the frequency of acquired infections in critically ill patients. The increasing knowledge about the metabolic effects of these nutritions offers therapeutic potential for the future, and might reduce the mortality of critically ill patients from nosocomial infections. However, at present, studies are necessary to find the best time for beginning and duration of the feeding. In addition, the optimal dosage and composition of these pharmacologically active substances has to be investigated.
Breath tests using 13C-labelled substrates require the measurement of 13CO2/12CO2 ratio in breath gas samples. Next to isotope ratio mass spectrometry (IRMS), which is very sensitive but also complex and expensive, alternatively isotope selective nondispersive infrared spectrometry (NDIRS) can be used to determine the 13CO2/12CO2 ratio in expired breath. In this study we compared NDIRS- with IRMS-results to investigate whether the less expensive and very simply to operate NDIRS works as reliable as IRMS. For this purpose we applicated 1- 13C-Phenylalanine to patients with advanced liver cirrhosis and healthy volunteers and took duplicated breath samples for IRMS and NDIRS at selected time points. Our data show a good correlation between these two methods for a small number of samples as required for simple breath tests. Longer series, where repeated measurements are required on the NDIRS instrument lead to a decreasing correlation. This indicates the superiority of IRMS concerning 13CO2-kinetics over longer time periods.
OBJECTIVE: To use stable isotopes for the analysis of hepatic metabolic pathways (urea synthesis, glucose production), comparing them in alcoholic and normal liver, in order to obtain specific and quantitative information on metabolic functions of the liver. PATIENTS AND METHODS: Urea and glucose production as well as alanine metabolism in the liver were studied by means of stable isotopes in 7 males with alcoholic liver cirrhosis (mean age 46 +/- 4 years; height 173 +/- 5 cm; weight 73 +/- 3 kg) and 7 healthy male volunteers as controls (age 26 +/- 3 years; height 180 +/- 5 cm; weight 75 +/- 6 kg). The plasma concentrations of adrenaline, noradrenaline, insulin, glucagon and amino-acids were also measured. RESULTS: Urea synthesis was lower in the cirrhosis patients than in the controls (3.3 +/- 2.2 mumol/kg.min vs 4.8 +/- 0.9 mumol/kg.min, P < 0.05). But there were no differences in glucose production, alanine metabolism and adrenaline concentrations. The concentrations of glutamine, phenylalanine, tyrosine, insulin, glucagon and noradrenaline were significantly raised in the cirrhotic patients, those of valine and leucine significantly lower. CONCLUSIONS: Contrary to hepatic glucose production, which was within normal limits, urea synthesis was reduced by 30% in the cirrhotic patients. The use of stable isotopes provided detailed information on specific metabolic processes in cirrhotic livers.
The object of this review is to demonstrate the non-nutritional importance of carbohydrates and fat as they represent the classic energy carriers in parenteral nutrition. Concerning the pathophysiological changes of organ metabolism and intermediary metabolism as well as the pharmacological function of this nutritive substrates it is necessary to adjust parenteral nutrition strategy to various clinical pictures. The major goals of parenteral applicated carbohydrates are to avoid hyperglycemia, to return the increased hepatic glucose production during trauma and sepsis back to normal, and to reduce protein catabolism. Realizing this goals the dosage of glucose infusion underlies close metabolic borders depending on the present disease. Because of favourable effects of hepatic glucose and protein metabolism, xylitol, a non-glucose polyol, represents an useful alternative energy source to glucose. The non-energetic nutrition therapy with fat consists of application of the essential fatty acids linoleic and alpha-linolenic acid and considers the immunmodulatory effects of various fatty acids as precursors in the eicosanoid metabolism. As demonstrated at the organ systems of liver and lung this pharmacological effects of any lipid infusion might influence specific organ functions.
In comparison to conventional operating technique endoscopic surgery reveals numerous advantages, particular rapid mobilisation and earlier discharge from observation. For a effective utilization of these advantages, it is desirable to have a efficient postoperative analgesic scheme, which can be continued into the period after discharge from hospital. In a randomised, prospective double-blind study we investigated the analgesic efficacy of dipyrone in 40 patients, scheduled for endoscopic abdominal surgery (mainly endoscopic cholecystectomy). Patients received before induction of anesthesia either dipyrone (1 g/100 ml NaCl i.v.) or placebo (100 ml NaCl i.v.). These infusions were repeated 6 h and 12 h after first application. After surgery all patients were allowed to self-administer buprenorphine intravenously from a PCA-pump (Bolus 30 micrograms, lockout 5 min in the recovery room, 30 min on the ward). Every hour for the first 6 h and after 24 h, cumulated doses of buprenorphine, pain scores (0-10), pulse, blood pressure and side effects were recorded. Dipyrone-treated patients had significantly less pain immediately after surgery and used a significantly lower cumulated dose of buprenorphine (-67%; 90 micrograms vs. 270 micrograms buprenorphine) in the first 24 h after surgery.
The aim of this study was to investigate metabolic changes during and after abdominal hysterectomy with specific regard to glycerol metabolism. Seven otherwise healthy patients with benign uterine myoma were enrolled in this study. Glycerol turnover and hepatic glucose production were measured before and after the operation by using stable-isotope technique ([1,1,2,3,3-2H5]-glycerol, [6,6-2H2]-glucose). Metabolic substrates (glycerol, nonesterified fatty acids, beta-hydroxybutyrate, glucose, lactate) and hormones (insulin, glucagon, cortisol, catecholamines) were determined pre-, intra- and postoperatively. Hysterectomy was associated with an increase of postoperative glycerol turnover from 3.56 +/- 1.28 to 6.46 +/- 2.44 mumol.kg-1.min-1 (P < 0.05). This increment was inversely related to the age of the patients (r = 0.872, P < 0.05). Glycerol concentration tended to increase perioperatively. These changes, however, were not of statistical significance. Hepatic glucose production and glucose plasma levels increased postoperatively from 9.75 +/- 1.61 to 12.79 +/- 1.45 mumol.kg-1.min-1 (P < 0.05) and 4.6 +/- 0.9 to 6.2 +/- 0.9 mmol/L (P < 0.05), respectively. Cortisol and catecholamine levels rose during and after surgery, while insulin and glucagon remained unchanged. The enhanced rate of lipolysis after hysterectomy was not detectable from plasma glycerol levels alone. The results of this study showed that using stable isotope technique allowed a more differentiated look at metabolic pathways than static plasma substrate concentrations, especially under perioperative conditions.