Analgetikakombinationen zur postoperativen Schmerztherapie

BACKGROUND

The supplementation of an opioid by a non-opioid analgesic is a widely accepted technique for the treatment of postoperative pain. However, it is still unclear whether a combination of different non-opioids has an advantage in terms of an improved analgesia and/or a reduction of the opioid-related adverse effects.

METHODOLOGY

A systematic analysis of the literature was performed searching for randomized, controlled trials studying the effects of a combination of two non-opioid analgesics in order to reduce postoperative opioid requirements and/or postoperative pain. Significant reduction of the postoperative opioid requirement and/or postoperative pain were defined as main rating criteria. To facilitate comparisons between the trials, the relative (proportional) reduction of postoperative opioid administration and the relative reduction of postoperative pain were calculated on defined pain scales.

RESULTS

A total of 25 trials were identified, mainly studies comparing non-steroidal anti-inflammatory drugs (NSAIDs) with paracetamol. Only 3 trials found a statistically improved analgesic efficacy and 15 studies did not show any relevant improvement or the combination group was only significantly superior to one of the groups receiving monotherapy. A further seven studies could not be evaluated due to methodological issues. There was no evidence for a significant reduction of opioid-induced adverse effects.

CONCLUSION

A combination of non-opioid analgesics, in particular NSAIDs with paracetamol, cannot be recommended at present due to the lack of data showing improved effectiveness.

Effect of a balanced anaesthetic technique using desflurane and remifentanil on surgical conditions during microscopic and endoscopic sinus surgery

OBJECTIVES

Controlled hypotension is used to improve surgical conditions during microscopic and endoscopic sinus surgery. Several drug combinations are suitable to provide deep and predictable level of anaesthesia combined with an exact control of intraoperative blood pressure. However, only little is known about the relative importance of the level of hypnosis on the one hand and analgesia on the other hand.

STUDY DESIGN

Prospective, randomized, patient and observer-blinded study.

METHODS

All 100 consecutive patients received a balanced anaesthesia technique using desflurane and remifentanil. Anaesthesia was desflurane-accentuated with remifentanil-supplementation (DARS-group: 1 MAC desflurane; remifentanil: 0.2 microg x kg(-1) x min(-1)) or remifentanil-accentuated with desflurane-supplementation (RADS-group: desflurane: 0.5 MAC; remifentanil: 0.4 microg x kg(-1) x min(-1)). Administration of anaesthetics performed to maintain a sufficient level of anaesthesia and to keep mean arterial pressure between 60 and 70 mmHg (8-9.3 hPa). The attending ENT-surgeons were unaware of the type of anaesthesia and rated general surgical conditions and the dryness of the operating site on a visual analogue scale (0-10 cm) and on a verbal rating scale immediately after surgery.

RESULTS

Blood pressure and heart rate was not different between the two groups. Dryness of the operating site was rated significantly better (p < 0.0001) in the DARS-group (median; 25th/75th-percentile: 2.0; 1.5-3.5 vs. RADS-group: 2.6; 2.0-4.0) but the overall rating of the surgical conditions did not differ between the groups (DARS-group: 2.0; 1.0-2.4 vs. RADS-group: 2.2; 1.5-3.2). Immediate postoperative recovery times were increased in the RADS-group, but there was no difference with respect to fit-for-discharge criteria one hour after surgery.

CONCLUSION

Balanced anaesthesia using high dose of desflurane offers small but statistically significant advantages with respect to dryness of the operating site compared to an opioid-accentuated anaesthesia technique. However, since the opioid-accentuated anaesthetic group had a faster immediate recovery both techniques are equally effective for microscopic and endoscopic sinus surgery.

Fine root biomass, necromass and chemistry during seven years of elevated aluminium concentrations in the soil solution of a middle-aged Picea abies stand

Toxic effects of aluminium (Al) on Picea abies (L.) Karst. (Norway spruce) trees are well documented in laboratory-scale experiments, but field-based evidence is scarce. This paper presents results on fine root growth and chemistry from a field manipulation experiment in a P. abies stand that was 45 years old when the experiment started in 1996. Different amounts of dissolved aluminium were added as AlCl3 by means of periodic irrigation during the growing season in the period 1997-2002. Potentially toxic concentrations of Al in the soil solution were obtained. Fine roots were studied from direct cores (1996) and sequential root ingrowth cores (1999, 2001, 2002) in the mineral soil (0-40 cm). We tested two hypotheses: (1) elevated concentration of Al in the root zone leads to significant changes in root biomass, partitioning into fine, coarse, living or dead fractions, and distribution with depth; (2) elevated Al concentration leads to a noticeable uptake of Al and reduced uptake of Ca and Mg; this results in Ca and Mg depletion in roots. Hypothesis 1 was only marginally supported, as just a few significant treatment effects on biomass were found. Hypothesis 2 was supported in part; Al addition led to increased root concentrations of Al in 1999 and 2002 and reduced Mg/Al in 1999. Comparison of roots from subsequent root samplings showed a decrease in Al and S over time. The results illustrated that 7 years of elevated Al(tot) concentrations in the soil solution up to 200 microM are not likely to affect root growth. We also discuss possible improvements of the experimental approach.

Aluminum dynamics in forest soil waters in Norway

We report on weekly aluminum (Al) concentration measurements in soil water from forested catchments monitored throughout Norway since 1986. Originating in acidification research, and thus accompanied by many other chemical variables, they constitute a comprehensive data set suited for analysis of short- as well as long-term variations in a geographic perspective. The Al time series at 21 sites are characterized by high temporal variability, seasonal behavior, and episodic events with peak values in the range 200-800 micromol/l, mostly caused by sea salts blown inland in storms, with a subsequent release of Al after cation exchange. Despite a clear south-north gradient in possible acidification over Norway, we found no indication of such south-north trends in Al chemistry, neither in mean values, maximum values, nor time trends. We identified two main drivers for variation in Al concentrations. The first one was sea salts, where Al was released to the soil solution after cation exchange. The second driver was high production of DOC, where Al was driven into the soil solution by complexation with DOC. There appears to be little risk for aluminum toxicity to trees in Norwegian forests. Except during occasional episodes, aluminum concentrations generally lay far below the supposed threshold values for toxic effects on Norway spruce, Scots pine and birch. Much dissolved aluminum was non-labile, and thus relatively non-toxic. Although the Ca2+/labile Al ratio was often below 1.0, considerable doubt exists as to the applicability of this variable in the field.

Formation of SWCnts in arc plasma: effect of graphitization of Fe-doped anode and optical emission studies

Fe-doped (ca. 1 at%) homogeneous graphite electrodes (with different graphite microcrystallites, degree of graphitization and, thereby, electrical conductivities) were used to produce single-walled carbon nanotubes (SWCNTs) in Ar/Kr/Xe-H2 arc plasma under pressure equal to 26 kPa. The use of electrode with the smaller primary particle size (about 5 nm) comparing to the well-graphitized electrode (25 nm) drastically increased the yield of SWCNTs in Ar-H2 arc plasma, while plasma parameters (temperature, C2 content, and namely carbon vapor pressure) remained on similar levels. However, the use of electrodes with larger grain size (25 nm) can lead to SWCNTs growth when they are arc ablated under the presence of Kr (or Xe)-H2 gas mixture. Thus, the mechanism of CNT formation seems to be more complex that the one involving only simple carbon species (e.g., C2).

Effect of mycophenolate mofetil on kidney graft function and body weight in patients with chronic allograft nephropathy

BACKGROUND

Chronic allograft nephropathy (CAN) is the most common cause of late graft loss. A beneficial effect of mycophenolate mofetil (MMF) on CAN was observed, although, due to the loss of body weight (BW) under MMF, serum creatinine (sCr) and reciprocal sCr may be unsuitable markers of graft function.

METHODS

In 17 kidney transplant patients with CAN, azathioprine (Aza) was replaced by MMF. The remaining therapy was not changed; specifically, the cyclosporine (CsA) dose was not decreased. The mean values and regression coefficients of reciprocal sCr, CCr, urinary creatinine excretion (uCr x V), proteinuria, BW, blood pressure (BP), serum cholesterol (sChol), and serum triglycerides (sTG) versus time were analyzed 12 months before and after institution of MMF by a paired-comparison t test.

RESULTS

The mean regression coefficient of reciprocal sCr differed significantly before and after conversion to MMF (mean -0.01 +/- 0.01 vs +0.012 +/- 0.029 mg/dL per month), suggesting improved graft function. However, the mean values of BW (74 +/- 15 vs 71 +/- 15 kg, P <.001) and uCr x V (1152 +/- 321 vs 1065 +/- 266 mg per 24 hours, P=.0897) decreased, making the increase in CCr less significant (mean -1.16 +/- 2.69 vs 0.40 +/- 1.79 mL/min per month, P <.05). BP, sChol, sTG, and proteinuria before and after conversion did not differ significantly. Among patients with long-term stable graft function at 36.5 +/- 16.9 months after conversion to MMF there was an almost significant improvement in renal protein excretion.

CONCLUSIONS

MMF improved graft function, although this effect was overestimated using reciprocal sCr. Other risk factors, such as BP, sChol, and sTG, showed no significant differences, suggesting that MMF accounted for the improvement in CAN. The course of proteinuria under MMF seems to be of prognostic significance.

Carbon arc plasma as a source of nanotubes: emission spectroscopy and formation mechanism

Diagnostics of carbon arc plasma by optical emission spectroscopy during the synthesis of carbon nanotubes is reviewed. Spatial distributions of temperature and C2 radicals in different plasmas are presented. The influence of gas pressure, anode composition, and reaction environment is discussed. Mechanisms of carbon nanotube formation are reviewed, with an emphasis on surface diffusion processes and catalytic effects.

Multiorgan dysfunction syndrome: how water might contribute to its progression

Multiorgan dysfunction syndrome (MODS) is one of the most frequent conditions encountered in intensive-care medicine. MODS is defined as total or partial loss of two or more organs with vital functions. The development of acute renal failure (ARF) in MODS leads to an additional aggravation with considerably higher hospital mortality than in other ICU patients with MODS. Whereas dissolved substances involved in the regulation of regional blood flow, endothelial cell injury, microvascular permeability, oxygenation, and nutrition of cells are at the focus of interest in MODS, hardly any scientific attention is paid to their main solvent water. An impaired renal water excretion and an increased metabolic water volume requiring excretion interfere with diffusive and convective oxygen transport through the different fluid compartments. It will be shown first that the ratio of U(osm)/ P(osm) appears to be a reliable tool to assess overhydration in ARF. Secondly, the limits of urinary output in response to water intake will be considered. Furthermore, the metabolic water formation by an enhanced degradation of endogenous protein and fat will be discussed. Finally, the daily caloric intake is questioned with respect to energy expenditure and metabolic water formation.

Gains of 12q are the most frequent genomic imbalances in adult fibrosarcoma and are correlated with a poor outcome

Comparative genomic hybridization was used to analyze 41 adult fibrosarcomas from 34 patients. Thirty-one patients showed in their tumors DNA sequence copy number changes (mean 11, range 3-25). The minimal common regions for the most frequent gains were narrowed down to 12q21 (18 cases); 12q14-q15 and 14q22 (16 cases each); 4q22, 7q31, and 14q23-q24 (15 cases each); and 4q21, 4q23-q24, 8q22, and 12q22 (14 cases each). Twenty-five high-level amplifications were observed in 12 samples. 12q21 and 18p were affected three times each; and 1p21, 4q31.3, 7p21, 12q14-q15, Xp22.1-p22.2, and Xq22-q23 two times each. Losses were less frequent than gains. Early stages of adult fibrosarcomas were characterized by frequent gains of chromosomes 2, 4q, and 14q, whereas gains of chromosomes 7 and 8q were associated with progression. Gains of 12q were frequent in all of the developmental steps of this soft-tissue sarcoma. By investigation of several tumors of the same patient, a number of corresponding changes were always detected. Adult fibrosarcomas from patients who died during the observation time showed statistically significant more frequent gains of 8q, 12q, 13q, and 15q compared to the fibrosarcomas of patients who are alive. Gains and high-level amplifications of 12q14-q22, which were the most frequent genomic imbalances, partly reflected an MDM2 amplification, indicating the importance of this region in the tumorigenesis of sarcomas. In adult fibrosarcomas, a gain of 12q22 correlated significantly (P = 0.028) with a poor overall survival rate.

[Mycotic aneurysms--A retrospective analysis]

12 patients (10 males and 2 females, average age 53 years) were operated upon in our hospital between 1994 and 1999 for mycotic aneurysms. The aneurysms were located in 7 patients in the aorto-iliac segment, 5 patients were treated for peripheral or visceral aneurysms. Two of these patients suffered from multiple aneurysms. When peripheral arteries were affected, a pulsatile tumour was felt. Most of these tumours developed in a relatively short period of time and sometimes a perivascular inflammation occurred. This was not the case when central arteries were attacked. A septic process or an infection, for example salmonella-enteritis, often preceded shortly the development of a mycotic aneurysm. In the case of an aneurysm of the aorto-iliac section we consider an in situ reconstruction with alloplastic material in combination with a perivascular debridement, lavage and omentum majus plastic as the treatment of choice. In peripheral arteries reconstruction should be performed with autologous vessels. Depending on the local findings, a perivascular debridement should also be performed in these cases. The reconstruction always should be combined with a calculated antibiotic therapy. Two of our patients died perioperatively. During follow up, 8 patients showed patent reconstructions and no signs of infection. The urgency of surgery depends on the level of inflammation and the existence of any secondary complications.

Decreased rate of coronary restenosis after lowering of plasma homocysteine levels

BACKGROUND

We have previously demonstrated an association between elevated total plasma homocysteine levels and restenosis after percutaneous coronary angioplasty. We designed this study to evaluate the effect of lowering plasma homocysteine levels on restenosis after coronary angioplasty.

METHODS

A combination of folic acid (1 mg), vitamin B12 (400 microg), and pyridoxine (10 mg)--referred to as folate treatment--or placebo was administered to 205 patients (mean [+/-SD] age, 61+/-11 years) for six months after successful coronary angioplasty in a prospective, double-blind, randomized trial. The primary end point was restenosis within six months as assessed by quantitative coronary angiography. The secondary end point was a composite of major adverse cardiac events.

RESULTS

Base-tine characteristics and initial angiographic results after coronary angioplasty were similar in the two study groups. Folate treatment significantly lowered plasma homocysteine levels from 11.1+/-4.3 to 7.2+/-2.4 micromol per liter (P<0.001). At follow-up, the minimal luminal diameter was significantly larger in the group assigned to folate treatment (1.72+/-0.76 vs. 1.45+/-0.88 mm, P=0.02), and the degree of stenosis was less severe (39.9+/-20.3 vs. 48.2+/-28.3 percent, P=0.01). The rate of restenosis was significantly lower in patients assigned to folate treatment (19.6 vs. 37.6 percent, P=0.01), as was the need for revascularization of the target lesion (10.8 vs. 22.3 percent, P=0.047).

CONCLUSIONS

Treatment with a combination of folic acid, vitamin B12, and pyridoxine significantly reduces homocysteine levels and decreases the rate of restenosis and the need for revascularization of the target lesion after coronary angioplasty. This inexpensive treatment, which has minimal side effects, should be considered as adjunctive therapy for patients undergoing coronary angioplasty.

Fluorine-18 fluorodeoxyglucose positron emission tomography in medullary thyroid cancer: results of a multicentre study

The aim of this study was to evaluate the clinical use of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in medullary thyroid cancer (MTC) on the basis of comparison with findings obtained using indium-111 pentetreotide (SMS), pentavalent technetium-99m dimercaptosuccinic acid (DMSA), technetium-99m sestamibi (MIBI), computed tomography (CT) and magnetic resonance imaging (MRI). One hundred FDG-PET examinations in 85 patients (40 males, 45 females) with elevated tumour marker levels and/or pathological findings on other imaging methods were evaluated retrospectively. Eighty-two patients were examined after total thyroidectomy, and the remaining three patients prior to surgery. Overall, 181 lesions could be identified with at least one of the imaging techniques. Fifty-five lesions were confirmed histologically. FDG-PET detected 123 of 181 sites, which is a lesion detection probability of 68%. In the 55 cases with histological confirmation, we found 32 true positive, 3 false positive, 11 true negative and 9 false negative lesions using FDG-PET, resulting in a sensitivity of 78% and a specificity of 79%. Sensitivity and specificity were, respectively, 25% and 92% for SMS, 33% and 78% for DMSA, 25% and 100% for MIBI, 50% and 20% for CT and 82% and 67% for MRI. Compared with morphological techniques and functional imaging methods with single-photon emitters, FDG-PET showed the highest lesion detection probability for MTC tissue, with a high sensitivity and specificity. It is concluded that FDG-PET is a useful method in the staging and follow-up of MTC.

Resting metabolic rate in chronic renal failure

OBJECTIVE

A decrease in resting metabolic rate (RMR) in patients with chronic renal failure was assumed to occur because of the decreasing oxygen consumption of the kidneys, which in healthy subjects, accounts for 7.2% of RMR. Contrary to this assumption, RMR per body weight in end-stage renal disease was increased.

DESIGN AND METHODS

To test the impact of chronic renal failure on the RMR, direct bedside calorimetry was performed on 51 outpatients (age, 53.2 +/- 13.9 y; creatinine clearance, 6.9 to 52 mL/min). Twenty two of 51 patients were examined repeatedly (at the start of the study, after 3 months, and after 6 months) during declining kidney function.

RESULTS

In the total group, RMR per body weight (RMR/BW) was 100.0 +/- 4.96 kJ/kg/day and RMR per body surface area (RMR/BSA) was 4.582 +/- 0.181 kJ/min/1.73m(2). RMR/BW and RMR/BSA correlated significantly with creatinine clearance (n = 51, r = -.763, P <.001; n = 51, r = -.557, P <.001). In the follow-up group, creatinine clearance decreased from 27.5 +/- 9.5 mL/min initially, to 19.4 +/- 6.25 mL/min at 3 months, to 13.0 +/- 3.8 mL/min at 6 months (P <.001), while RMR/BW and RMR/BSA increased from 98.28 +/- 6.3, to 101.64 +/- 5.46, to 105.42 +/- 6.3 kJ/kg BW/d (P <.005), respectively, and 4.41 +/- 0.126, to 4.578 +/- 0.168, to 4.704 +/- 0.168 kJ/min/1.73 m(2) (P <.05), respectively.

CONCLUSION

Taking into account the reduced oxygen consumption of the shrinking kidneys, the normal RMR suggests an increased energy expenditure per body cell mass. The raising RMR in deteriorating excretory kidney function reflects the increasing energy expenditure in progressive chronic renal failure.