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M Georgieff

Publications and source records attributed to M Georgieff.

At least 19 recordsLinked to original sources
PubMed1997

[Liver urea and glucose production in patients with alcohol-induced cirrhosis].

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.

Adult↗
PubMed1997

Assessment of perioperative glycerol metabolism by stable isotope tracer technique.

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.

Adult↗
PubMed1997

[Xenon].

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Anesthesia, Closed-Circuit↗
PubMed1997

[Effectiveness of anesthetic gas scavengers fulfilling EN 740 requirements with reference to equipment leakage and fresh gas flow].

PURPOSE: During inhalation anaesthesia, contaminations of the working environment be anaesthetic volatiles and nitrous oxide occur. The amount of leaking gases is influenced by leakages of the anaesthetic ventilator, by fresh-gas flows and by the effectivity of the scavenging system. Since 1st January 1996 new ventilators have to be equipped with scavenging devices according to the European standard EN 740. We measured the effectivity of this system with anaesthetic ventilators of a type that is now superseded (mean leakage rate 100 ml/min) and recent devices (mean leakage rate 5 ml/min) using high and low fresh-gas flows. MATERIAL AND METHODS: The anaesthetic ventilators were placed in a non-air-conditioned area. A test lung was ventilated with gas flows of 1 l/min, 3 l/min and 6 l/min (concentrations of nitrous oxide 70%, Enflurane 1%). The ventilation time in each case was 1 h. The minute volume was set to 8 l/min. At 2-minute intervals the concentrations of nitrous oxide and enflurane were measured by a multigas monitor Brüel & Kjaer 1302. The experiments were carried out with an old scavenging device according to DIN 13260 and a new device according to EN 740. RESULTS: Using the scavenging device according to DIN 13260, the concentrations of the pollutant gases were significantly dependent on the fresh-gas flows. No differences were found when using old or new anaesthetic ventilators. Medians of nitrous oxide (n2o) and Enflurane (e): 6 l/min: (n2o) 204 ppm (e) 4.3 ppm 3 l/min: (n2o) 115 ppm (e) 2.1 ppm 1 l/min: (n2o) 61 ppm (e) 0.97 ppm. Scavenging devices according to EN 740 significantly reduced the amount of emitted pollutants. No dependency on fresh-gas flows could be detected. 6 l/min: (n2o) 11.25 ppm (e) 0.05 ppm 3 l/min: (n2o) 10.12 ppm (e) 0.0 ppm 1 l/min: (n2o) 9.5 ppm (e) 0.0 ppm. CONCLUSIONS: The formerly reported dependence of the room air concentrations of anaesthetic volatiles and nitrous oxide from the fresh gas flow are caused by the spillage of pollutants through scavenging devices according to DIN 13260. The use of systems according to EN 740 is not only useful in new devices but must also be recommended for superseded models of anaesthetic ventilators.

Air Pollutants, Occupational↗
PubMed1997

Effects on haemodynamics and catecholamine release of xenon anaesthesia compared with total i.v. anaesthesia in the pig.

In order to investigate haemodynamic response and catecholamine release during anaesthesia with xenon, we conducted a study on 28 pigs which were allocated randomly to one of four groups: total i.v. anaesthesia with pentobarbitone and buprenorphine, and xenon anaesthesia with inspiratory concentrations of 30%, 50% or 70%, respectively, supplemented with pentobarbitone. Haemodynamic variables were measured using arterial and Swan Ganz catheters. Depth of anaesthesia was monitored using spectral edge frequency analysis. Plasma concentrations of dopamine, noradrenaline and adrenaline were measured by high pressure liquid chromatography. All haemodynamic variables and plasma concentrations of dopamine and noradrenaline remained within normal limits. Adrenaline concentrations were reduced significantly in all groups. Xenon anaesthesia was associated with a high degree of cardiovascular stability. Significant reduction in adrenaline concentrations at inspiratory xenon concentrations of 30% and 50% can be explained by analgesic effects of xenon below its MAC value.

Anesthetics, Inhalation↗
PubMed1997

Reduced postoperative analgesic demand after inhaled anesthesia in comparison to combined epidural-inhaled anesthesia in patients undergoing abdominal surgery.

We studied the effect of epidural/general combination anesthesia, in comparison to inhaled anesthesia, on postoperative pain and analgesic consumption in patients undergoing upper abdominal surgery. Anesthesia was induced with propofol and maintained with enflurane in 70% N2O as necessary to maintain arterial blood pressure within 20% of baseline. Group I received bupivacaine 0.25% 0.2 mL/kg and sufentanil 1 microgram/kg 65 +/- 3 min before dermal incision and 0.1 mL/kg bupivacaine 0.25% + sufentanil 2 micrograms/mL (BS) every hour thereafter. Group II received 0.2 mL/kg of BS 316 +/- 15 min after dermal incision in the recovery room. Postoperative patient-controlled epidural analgesia (PCEA) with BS was provided. Pain intensities and consumption of PCEA BS were recorded on postoperative days (PODs) 1 to 5. Inspiratory fraction of enflurane was lower (0.5% +/- 0.01% vs 1.6% +/- 0.04%; P < 0.001) in Group I compared with Group II. Cumulative postoperative consumption of PCEA BS was higher in Group I compared with Group II from the evening of POD 2 until the end of the study (301 +/- 19 mL vs 249 +/- 17 mL; P < 0.001), while pain intensities were comparable at all times. The intraoperative effects of combined BS and enflurane/N2O (inspiratory fraction [Fi] approximately 1 minimum alveolar anesthetic concentration [MAC]) did not preempt postoperative pain in contrast to enflurane/N2O anesthesia (Fi approximately 2.8 MAC).

Abdomen↗
PubMed1997

Effects of a dobutamine-induced increase in splanchnic blood flow on hepatic metabolic activity in patients with septic shock.

BACKGROUND: Septic shock leads to increased splanchnic blood flow (Qspl) and oxygen consumption (VO2spl). The increased Qspl, however may not match the splanchnic oxygen demand, resulting in hepatic dysfunction. This concept of ongoing tissue hypoxia that can be relieved by increasing splanchnic oxygen delivery (DO2spl), however, was challenged because most of the elevated VO2spl was attributed to increased hepatic glucose production (HGP) resulting from increased substrate delivery. Therefore the authors tested the hypothesis that a dobutamine-induced increase in Qspl and DO2spl leads to increased VO2spl associated with accelerated HGP in patients with septic shock. METHODS: Twelve patients with hyperdynamic septic shock in whom blood pressure had been stabilized (mean arterial pressure > or = 70 mmHg) with volume resuscitation and norepinephrine received dobutamine to obtain a 20% increase in cardiac index (CI). Qspl, DO2spl, and VO2spl were assessed using the steady-state indocyanine green clearance technique with correction for hepatic dye extraction, and HGP was determined from the plasma appearance rate of stable, non-radio-active-labeled glucose using a primed-constant infusion approach. RESULTS: Although the increase in CI resulted in a similar increase in Qspl (from 0.91 +/- 0.21 to 1.21 +/- 0.34l.min-1.m2; P < 0.001) producing a parallel increase of DO2spl (from 141 +/- 33 to 182 +/- 44 ml.min-1.m2; P < 0.001), there was no effect on VO2spl (73 +/- 16 and 82 +/- 21 ml.min-1.m2, respectively). Hepatic glucose production decreased from 5.1 +/- 1.6 to 3.6 +/- 0.9 mg.kg-1.min-1 (P < 0.001). CONCLUSIONS: In the patients with septic shock in whom blood pressure had been stabilized with volume resuscitation and norepinephrine, no delivery-dependency of VO2spl could be detected. Oxygen consumption was not related to the accelerated HGP either, and thus the concept that HGP dominates VO2spl must be questioned in well-resuscitated patients with septic shock.

Adrenergic beta-Agonists↗
PubMed1997

Regulation of beta 2-adrenergic receptors on mononuclear leukocytes in patients with acute ischemic heart disease.

OBJECTIVE: To investigate relationships between acute adrenergic stress, plasma catecholamine concentrations, and beta 2-adrenergic receptors. DESIGN: Prospective, descriptive study. SETTING: Emergency medical service at a university hospital. PATIENTS: Twenty-seven patients with out-of-hospital cardiac arrest (n = 11), myocardial infarction (n = 6), and angina pectoris (n = 10), and 12 control subjects. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Mononuclear leukocyte beta 2-adrenergic receptor density and affinity were measured in patients 15 mins after successful cardiopulmonary resuscitation and after the diagnosis of myocardial infarction or angina pectoris, respectively, and were measured as well in control subjects. Plasma concentrations of catecholamines, glucose, and lactate were simultaneously measured with heart rate and blood pressure. After cardiac arrest, the density of beta 2-adrenergic receptors (1858 +/- 188 sites/cell [p < .01]), plasma epinephrine concentration (31,990 +/- 14,526 pg/mL [174.6 +/- 79.3 nmol/L] [p < .01]), heart rate (100 +/- 6 beats/min [p < .01]), glucose concentration (14.9 +/- 0.8 mmol/L [p < .01]), and lactate concentration (10.9 +/- 0.6 mmol/L [p < .01]) were increased in patients compared with those values in healthy controls. CONCLUSION: Acute maximal stress, such as after cardiac arrest, is associated with an increase in the density of beta 2-adrenergic receptors on mononuclear leukocytes derived from patients after successful cardiopulmonary resuscitation.

Acute Disease↗
PubMed1997

Effects of basic fibroblast growth factor on hippocampal neurons after axonal injury.

OBJECTIVE: Axons of adult central nervous system neurons fail to regenerate after diffuse axonal injury in head trauma. Basic fibroblast growth factor (bFGF) has been reported to enhance neuritic extensions after neuronal injury in immature nerve cells. To investigate the effects of bFGF on adult neurons and axonal reoutgrowth, differentiated nerve cells were axonally transected and bFGF was applied. DESIGN: Cell culture study with primary rat hippocampal neurons. MATERIALS AND METHODS: After axotomy, hippocampal cultures were maintained untreated or in the presence of 0.5, 1, 10, or 20 ng/mL bFGF and evaluated over a 7-day period after injury. MEASUREMENTS AND MAIN RESULTS: Seven days after injury, axotomy decreased cell survival to 65%, increased [3H]arachidonic acid release 1.8-fold from prelabeled cells, and showed negligible effects on neuronal dendrites. bFGF reduced this neurodegeneration at all doses applied. bFGF at 10 ng/mL most efficiently increased live cells to 85% and decreased [3H]arachidonic acid release from prelabeled cells to control values (p < 0.01, vs. damaged cells). Furthermore, 10 ng/mL bFGF induced axonal branching and the longest axonal re-extensions from 60 +/- 8 to 377 +/- 10 microns 7 days after injury (p < 0.01, vs. damaged cells). CONCLUSIONS: bFGF increased cell survival and supported axonal re-elongations in adult hippocampal neurons in vitro when applied after axotomy. bFGF may play a role in new therapeutic concepts for the management of axonal injury after head trauma.

Animals↗
PubMed1997

Perioperative respiratory events in smokers and nonsmokers undergoing general anaesthesia.

BACKGROUND: The prevalence of respiratory diseases in smokers and nonsmokers and the incidence of perioperative respiratory events (PREs) were investigated for patients undergoing general anaesthesia. The aim was to quantify well-known problems and to identify possible new associations between smoking and PREs. METHODS: From July 1992 to December 1994, risk factors, demographic data, and PREs were documented by an automatically readable anaesthetic record (ARAR). PREs were used as defined by the German Society of Anaesthesiology and Intensive Care. RESULTS: Of 26961 subsequent anaesthesias in adults, 7122 (26.4%) were performed in smokers with a prevalence of chronic bronchitis of 23.3% (4.8% in nonsmokers). 1573 PREs occurred in 1397 (5.2%) of all anaesthetics. 459 events concerned intubation problems and problems in technical airway management. 1114 specific respiratory events (SPREs) like re-intubation, laryngospasm, bronchospasm, aspiration, hypoventilation/hypoxaemia and others had a total incidence of 5.5% in smokers and 3.1% in nonsmokers. The relative risk (RR) of SPREs was 1.8 in all smokers, 2.3 in young (16-39 years) smokers, and 6.3 in obese young smokers. The RR of perioperative bronchospasm was 25.7 in young smokers with chronic bronchitis. CONCLUSION: The impact of smoking on perioperative respiratory problems should make anaesthetists take this widespread preoperative condition seriously, particularly in young adults. The presented method of incident reporting (based on a national classification) could contribute to future research in anaesthetic epidemiology.

Adolescent↗
PubMed1997

Shed mediastinal blood in 500 elective cardiac surgery patients: is there enough for retransfusion routinely?

OBJECTIVE: Since an increased use of several blood salvaging measures has contributed to a reduction in perioperative blood loss and the requirement for banked blood in recent years, the aim of this study was to establish current postoperative drainage losses in order to evaluate whether homologous retransfusion may be a useful measure to reduce autologous transfusion in elective cardiac surgery. DESIGN/SETTING: This prospective clinical investigation was performed at a University Intensive Care Unit during the first six hours following cardiac surgery. PATIENTS: 373 men and 127 women undergoing elective cardiac surgery were investigated. MEASURES: The amount of shed blood was measured four and six hours postoperatively. RESULTS: The average blood loss was higher in men than in women both in all operations as a whole (men, four hours: 223+/-73 ml, six hours 270+/-95 ml; women, four hours: 156+/-25 ml, six hours 195+/-22 ml), in valve replacement (men, four hours: 299+/-87 ml, six hours 350+/-101 ml; women, four hours: 187+/-30 ml, six hours: 219+/-31 ml) and in coronary artery bypass grafting (men, four hours: 197+/-69 ml, six hours: 242+/-83 ml; women, four hours: 128+/-15 ml, six hours: 173+/-18 ml). A blood loss of 400 ml was exceeded in 13% of men after valve replacement four and six hours postoperatively. In all other groups, less than 8% of patients had a loss of more than 400 ml both after four and after six hours. CONCLUSIONS: Postoperative drainage losses in elective cardiac surgery patients are small and a measurable advantage from retransfusion seems to be unlikely. We therefore endorse the routine use of shed mediastinal blood retransfusion in these patients.

Blood Loss, Surgical↗
PubMed1996

The effect of basic fibroblast growth factor on glutamate-injured neuroarchitecture and arachidonic acid release in adult hippocampal neurons.

During development in culture, basic fibroblast growth factor (bFGF) protected immature primary hippocampal neurons against glutamate-induced neurotoxicity. We investigated the effects of bFGF on mature, differentiated rat hippocampal neurons cultured for 10-12 days after an 8-min exposure to 500 microM glutamate. Seven days post-injury, hippocampal cells demonstrated severe reductions in cellular viability and axonal and dendritic outgrowth, which were accompanied by a marked increase in [3H]arachidonic acid (ARA) release from prelabelled neurons. bFGF applied post-injury attenuated cell death and cytoarchitectural destruction at all concentrations used (500 pg/ml, 1, 10, 20 ng/ml). However, neurite elongation and branching processes were only significantly protected by 10 ng/ml bFGF. [3H]ARA release decreased in a dose-related fashion within a concentration range of 1-10 ng/ml bFGF. 20 ng/ml bFGF was not superior to 10 ng/ml bFGF. Therefore, bFGF's neurotropic actions appear to be concentration-dependent. Our data suggest that bFGF applied post-injury may have a neuroprotective potential for mature, differentiated, completely polarized hippocampal neurons.

Animals↗
PubMed1996

The Erlanger Microlightguide Photometer: a new concept for monitoring intracapillary oxygen supply of tissue--first results and a review of the physiological basis.

The local oxygen supply to the skin immediately before and after withdrawal of blood was appraised in 18 healthy test subjects by measuring the intracapillary hemoglobin oxygenation (HbO2). The investigation was carried out with the Erlanger Microlightguide Photometer (EMPHO). EMPHO measurements are based on the registration of tissue remission spectra from which the HbO2 values are calculated using the Kubelka-Munk theory. The results show that global parameters do not reflect the supply of oxygen to the tissue; for example, in hypovolemia, the physiological response to the pathophysiological stimulus is centralization. This is manifested at a very early stage in the skin, before the oxygen supply to other organs (e.g., liver, kidney, gut) is affected. The disturbance of the local cutaneous oxygen supply is reflected in a change in the intracapillary hemoglobin oxygenation of the skin. Hence, one might consider measurements of the local oxygen supply to the skin as an early indicator for centralization.

Hemoglobinometry↗
PubMed1996

The effect of human growth hormone therapy on L-(methyl-2H3)-leucine turnover and urinary pseudouridine concentration in patients with Ullrich-Turner syndrome.

UNLABELLED: The effect of daily human growth hormone (hGH) injections (3 I.U./m2/day) on tissue anabolism was determined in six patients with Ullrich-Turner syndrome (XO) (8.7-19 years of age) using novel techniques such as whole body leucine kinetics during continuous infusion of L-(Methyl-2H3)-leucine and urinary pseudouridine (5-ribosyluracil) excretion on the one hand and traditional methods like serum urea and amino acid concentrations on the other. Pseudouridine is only found in ribonucleic acid (RNA) and is neither reincorporated nor catabolically broken down and is therefore considered an ideal index of whole body RNA turnover. The mean L-(Methyl-2H3)-leucine turnover of the six XO patients before hGH was 1.90 +/- 0.15 mumoles/kg per minute. After 3 months of hGH-treatment it had increased in three patients, whereas it had decreased in the other three. The results obtained with the stable isotope technique were correlated with the urinary pseudouridine concentrations (r = 0.68; P < 0.01). The growth rates were positively correlated with leucine turnover (r = 0.63; P < 0.02) and urinary pseudouridine concentration (r = 0.73; P < 0.006) as well as negatively correlated with the serum urea concentrations r = -0.62; P < 0.03). The decrease in the individual serum urea concentrations were tightly correlated with the hGH induced change in growth rate (r = -0.90; P < 0.01). The individual bone ages were negatively correlated with the hGH induced changes in leucine turnover (r = -0.77; P < 0.003) as well as with the urinary pseudouridine concentrations (r = -0.87; P < 0.0002). The hGH effect on leucine and RNA turnover, showing effectiveness only until a developmental age between 11 and 12 years, leads the discussion of the ideal moment of oestrogen supplementation when girls with Ullrich-Turner syndrome are treated with hGH in early adolescence. CONCLUSION: The protein metabolism of patients with Ullrich-Turner syndrome is influenced by hGH in an age dependent manner. In a clinical setting, pseudouridine, an easily determined derivative of ribonucleic acids, may be able to replace the tedious work with expensive stable isotopes when questions related to tissue anabolism are to be answered.

Adolescent↗
PubMed1996

Aerosolized prostacyclin and inhaled nitric oxide in septic shock--different effects on splanchnic oxygenation?

OBJECTIVES: To compare the effects of inhaled nitric oxide and aerosolized prostacyclin (PGI2) on hemodynamics and gas exchange as well as on the indocyanine-green plasma disappearance rate and gastric intramucosal pH in patients with septic shock. DESIGN: Prospective, randomized, interventional clinical study. SETTING: Intensive care unit in a university hospital. PATIENTS: Sixteen patients with pulmonary hypertension and septic shock according to the criteria of the ACCP/SCCM consensus conference all requiring norepinephrine and/or epinephrine to maintain mean arterial blood pressure above 65 mmHg. METHODS AND INTERVENTIONS: Patients were randomly assigned to receive either nitric oxide or aerosolized prostacyclin. Nitric oxide was inhaled using a commercially available delivery system, prostacyclin was administered with a modified ultrasound nebulizer. Both nitric oxide and prostacyclin were incrementally adjusted to obtain a 15% decrease of mean pulmonary artery pressure. Hemodynamics and gas exchange as well as indocyanine-green plasma disappearance rate and gastric intramucosal pH were determined at baseline after 90 min in steady state, after 90 min of nitric oxide inhalation or prostacyclin aerosol administration had elapsed in stable conditions, and after 90 min in stable conditions after nitric oxide or prostacyclin withdrawal. RESULTS: Both inhaled nitric oxide and aerosolized prostacyclin selectively reduced the mean pulmonary artery pressure from 35 +/- 4, 30 +/- 4 mmHg (p < 0.05) and 34 +/- 4 to 30 +/- 3 mmHg (p < 0.05) respectively; after removal of nitric oxide and prostacyclin, the mean pulmonary artery pressure returned to the baseline values. Systemic hemodynamics remained unaltered during the vasodilator treatment. While the mean PaO2 was not significantly influenced, it increased in 4/8 of the NO- and 3/8 of the PGI2-treated patients. Neither of the drugs influenced indocyanine-green plasma disappearance rate, but prostacyclin--unlike nitric oxide--significantly increased gastric intramucosal pH (from 7.26 +/- 0.07 to 7.30 +/- 0.05, p < 0.05) which remained elevated in four of these patients after prostacyclin removal, and decreased the arterial-gastric mucosal pressure of carbon dioxide gap from 19 +/- 6 to 15 +/- 4 mmHg (p < 0.05). CONCLUSIONS: Our data suggest that aerosolized prostacyclin--unlike nitric oxide--has similar beneficial effects on splanchnic perfusion and oxygenation as intravenous prostacyclin without detrimental effects on systemic hemodynamics. The different effects of prostacyclin and nitric oxide might be explained by the longer half-life of prostacyclin associated with a certain spillover into the systemic circulation.

Administration, Inhalation↗
PubMed1996

[Combined "3-in-1"/sciatic nerve block. Block effectiveness, serum level and side effects using 700 mg mepivacaine 1% without and with adrenaline and prilocaine 1%].

UNLABELLED: A high dose of local anaesthetic is necessary for the combined "3-in-1"/sciatic nerve block. Prilocaine is recommended for its low toxicity. However, in some patients prilocaine results in pronounced methaemoglobin formation due to toludine. Little has been known hitherto about the use of high-dose mepivacaine for the combined 3-1/sciatic nerve block. This study was undertaken to compare the use of 700 mg mepivacaine 1% and of 700 mg prilocaine 1%. METHODS: The study was approved by the ethics committee of our hospital. Once their informed consent had been obtained in writing 3 x 20 patients (ASA 1-2) undergoing planned surgery on the foot or ankle joint were enrolled in the study. The patients were randomized to the following three groups on a double-blind basis: group 1,700 mg mepivacaine without epinephrine; group 2,700 mg mepivacaine with 0.2 mg epinephrine (1:350,000); group 3,700 mg prilocaine 1%. Arterial blood samples for determination of local anaesthetic serum levels were collected over a 120-min period. We determined methaemoglobin and oxygen saturation before and 120 min after the blockade and continued these measurements for 6 h in group 3. At 15-min intervals, all patients were questioned about early signs of toxicity. The perioperative monitoring including blood pressure, ECG and pulse oximetry. Data were analysed using ANOVA and Student's t-test, P < 0.05 considered statistically significant. RESULTS: The blocking efficacy did not differ among the groups (groups 1, 2, 3:90%, 95%, 90%). The maximum mepivacaine serum level in group 1 was 3.91 micrograms/ml +/- 0.95 and 2.94 micrograms/ml +/- 0.58 in group 2 (Fig. 2). Over the entire observation period the addition of epinephrine resulted in a significant reduction of the serum level (between 60.3% at t = 15 min and 19.7% at t = 120 min). In the prilocaine group the maximum serum level was 2.07 micrograms/ml +/- 0.56, significantly less than in either mepivacaine group. No patient showed signs or symptoms of local anaesthetic toxicity. In the prilocaine group there was wide variation in methaemoglobin formation among the patient, with a median of 10.1% (Fig. 3, Table 3). Three patients showed a maximum methaemoglobinemia between 16% and 17%. Five patients were still cyanotic after 6 h when they were transferred to the ward. The fractional SaO2 values amounted to 88% (median) with a minimum of 80.3%. CONCLUSION: Both mepivacaine 1% and prilocaine 1% are appropriate local anaesthetics for the combined 3-in-1/sciatic nerve block at a dose of 700 mg. There was no difference in the blocking efficacy. No patient showed clinical signs or symptoms of a local anaesthetic toxicity. Following prilocaine we are sometimes faced with high methaemoglobinemia, which may necessitate prolonged monitoring.

Adult↗
PubMed1996

[The effect of a heat and moisture exchanger (HME) on bronchial mucus transport in a closed inhalation anesthesia system].

UNLABELLED: The administration of dry anaesthetic gases for ventilation leads to morphological changes of the tracheobronchial epithelium that may cause postoperative pulmonary complications. Therefore, additional humidification with a heat and moisture exchanger (HME) is suggested for ventilation during anaesthesia, particularly when using semi-open breathing systems. Recommendations concerning the use of a HME in the semi-closed system are controversial. There are no data in the literature as to whether a HME improves mucociliary transport under these conditions. We therefore studied bronchial mucus transport velocity (BTV) with and without the use of a HME in the semi-closed circle system in humans. PATIENTS AND METHODS: The study was approved by the ethics committee of our hospital. In a prospective, randomised trial a total of 22 patients undergoing major abdominal surgery were investigated. In all patients anaesthesia was induced and maintained with midazolam, fentanyl, and vecuronium. After intubation, a HME (BACT/VIRAL HME, Pharma Systems AB, Sweden) was inserted between the endotracheal tube and ventilation tubing in 11 patients; the other 11 were ventilated without a HME and served as controls. Ventilation was assisted with a fresh flow of 3 in a semi-closed system (Dräger Sulla 808 V with an 8 ISO circle system and Ventilog 2 ventilator, Drägerwek AG, Germany) and a 2:1 mixture of nitrous oxide and oxygen. The fresh gas passed through the soda lime canister. At the end of the operation BTV was measured with a small volume of albumin microspheres labeled with technetium Tc99m, which was deposited on the dorsal surface at the lower ends of the right and left main bronchi via a catheter placed in the inner channel of a fibre-optic bronchoscope. RESULTS: The two groups were comparable with regard to age, sex, preoperative lung function, duration of mechanical ventilation, and dose of anaesthetics. There were no statistically significant differences in the BTVs. DISCUSSION: BTV does not improve with the use of a HME in the semi-closed circle system with a fresh gas flow of 31. With modern anaesthesia machines lower fresh gas flows should be administered, whereby the humidity and temperature of the inspired gases are further increased.

Adult↗