The effect of different stages of neuromuscular block on the bispectral index and the bispectral index-XP under remifentanil/propofol anesthesia

Facial electromyographic activity and neuromuscular block could influence bispectral index (BIS) depth of anesthesia monitoring. In this study we examined, in 30 patients undergoing general surgical procedures, the effect of different stages of neuromuscular block on BIS monitoring and compared the conventional A-2000 BIS trade mark (BIS(3.4)) with the new BIS-XP trade mark (BIS(XP)). At deep surgical anesthesia BIS(3.4) of approximately 40, under a propofol 3.61 microg/mL target-controlled infusion and a 0.15-0.3 microg. kg(-1). min(-1) remifentanil infusion, mivacurium 0.15 mg/kg was administered. The onset of neuromuscular block triggered a brief transient odd divergence in response that manifested as a BIS(3.4) increase from 43 +/- 4 to 49 +/- 7 (P = 0.007) and a BIS(XP) decline from 41 +/- 3 to 35 +/- 3 (P = 0.003) at 1 +/- 0.2 min. Then, 2.5 +/- 1 min after mivacurium administration, both monitors returned to baseline values of 43 +/- 5 and 40 +/- 4, respectively. After that, BIS(3.4) and BIS(XP) did not significantly change during complete neuromuscular block or during various levels of neuromuscular recovery. At all phases, BIS(XP) was significantly lower than BIS(3.4). Our study indicated that the BIS(3.4)/BIS(XP) bias and the wide limits of agreement do not allow values given by the two monitors to be used interchangeably.     

The value of a noninvasive diagnostic approach to mediastinal masses

BACKGROUND: Mediastinal tumors show a wide variability, and therefore, a standardized diagnostic and therapeutic workup is instrumental. We subdivided mediastinal tumors into nonlymphatic mediastinal tumors (NLMTs), most of which require surgical resection without need of preoperative histology, and mediastinal lymphadenopathy (MLA), requiring surgical biopsy for exact histologic classification. We investigated the accuracy of noninvasive diagnostic studies distinguishing between the two groups of MLA and NLMT. METHODS: A retrospective analysis was performed on patients who had previously undergone surgery on mediastinal tumors. Their data were statistically analyzed (chi2 test, logistic regression analysis), and the values of medical history, physical examination, laboratory tests, and computerized tomography scan discriminating between MLA and NLMT were assessed. RESULTS: Out of 299 patients included in the study, 242 (80.9%) had MLA and 57 (19.1%) had NLMT. Sensitivity and specificity of noninvasive investigations for differentiation of MLA and NLMT were 98.2% and 86.0%, respectively. Whereas the prevalence of thoracic symptoms such as shortness of breath, cough, or chest pain was similar in both groups (MLA, 165 [69.3%]; NLMT, 41 [69.5%]; p = 0.98), systemic symptoms, including fever, night sweats, or weight loss (MLA, 110 [49.8%]; NLMT, 17 [29.3%]; p < 0.01), and signs of inflammation, such as c-reactive protein, erythrocyte sedimentation rate, and leukocytosis (MLA, 202 [85.6%]; NLMT, 34 [57.6%]; p < 0.001), were significantly more common in MLA. CONCLUSIONS: Noninvasive diagnostic procedures, including medical history, physical examination, laboratory tests, and computerized tomographic scan, are highly sensitive in detecting MLAs that should undergo surgical biopsy. Our data suggest confirming all suspected NLMTs by fine needle aspiration (FNA) biopsy before surgery.     

Opioids. Old myths,new myths and the future

Ohne Zusammenfassung Prof.Dr. Michael Zenz Universit?tsklinik für Anaesthesiologie, Intensiv- und Schmerztherapie der BG-Kliniken Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44789 Bochum, E-Mail: michael.zenz@ruhr-uni-bochum.de     

Prevention of heterocyclic amine-induced DNA damage in colon and liver of rats by different lactobacillus strains

The aim of the present study was to investigate the impact of four different lactobacillus (LB) strains, namely Lactobacillus bulgaricus 291, Streptococcus thermophilus F4, S.thermophilus V3 and Bifidobacterium longum BB536, which are used for the production of yogurt, on the DNA-damaging effects of heterocyclic aromatic amines (HCAs). Male F344 rats were treated orally with HCA mixtures containing 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-amino-3,4,8-trimethyl-3H-imidazo[4,5-f]quinoxaline, 2-amino-9H-pyrido[2,3-b]indole and 2-amino-3-methyl-3H- imidazo[4,5-f]quinoline, which were representative of the HCA contents found in fried beef ('beef mix') and chicken ('chicken mix'). Suspensions of LB were given by gavage to the animals simultaneously with and at different time periods before administration of the HCAs. Subsequently, the extent of DNA migration was measured in colon and liver cells in single cell gel electrophoresis (SCGE) assays. All four strains caused complete inhibition of DNA damage induced with beef mix after administration of 1 x 1010 LB cells/animal, whereas with chicken mix only marginal (non-significant) effects were seen. The inhibition of beef-induced DNA damage was dose dependent and was still significant when 1 x 107 cells/animal were administered. Kinetics studies showed that the protective effects were still significant when LB was given 12 h before the beef mix. A comparison of the present results with chemical analytical data from in vitro experiments suggests that the strong reduction in DNA migration seen in the animals can be only partly explained by direct binding effects. The results of the present study show that LB are highly protective against the genotoxic effects of HCAs under conditions which are relevant for humans and provide a possible explanation for the reduced colon cancer rates observed in some studies in individuals with either high LB counts in their feces or with a high consumption of LB-containing foods.     

Guidelines -- safety net

Ohne Zusammenfassung Prof.Dr. Ch.Maier Abteilung Schmerztherapie, Berufsgenossenschaftliche Kliniken Bergmannsheil, Universit?tsklinik, Bürkle-de-la-Camp-Platz 1, 44789 Bochum, E-Mail: christoph.maier@rub.de     

Novel potential uses of thalidomide in the management of pain? A review of the literature

Thalidomide was introduced as a sedative and antiemetic agent to the European market in the late 1950s. However, it soon became clear that a hitherto unheard-of incidence of severe birth defects was due to the maternal use of thalidomide and the drug was withdrawn from the market. Despite its teratogenesis, thalidomide is currently being rediscovered because of its known spectrum of anticachectic, antiemetic, mildly hypnotic, anxiolytic, anti-inflammatory, antiangiogenic, and analgesic properties. The mechanism of action of thalidomide is probably based on its immunomodulatory effect, namely the suppression of production of tumor necrosis factor alpha and the modulation of interleukins. A striking but not well-known finding is the effectiveness of thalidomide as an analgesic or analgesic adjuvant. During the early era of thalidomide use, the drug was shown to enhance the analgesic efficacy of a combined treatment with acetylsalicylic acid, phenacetin, and caffeine (APC) by testing "normal volunteers, using electrical stimulation of teeth." The combination of thalidomide and APC was superior to other combinations (APC alone, APC and codeine) with respect to both the total analgesic effect and the duration of this analgesic effect. In 1965 thalidomide was found to be effective in treating the painful subcutaneous manifestations of the leprosy-associated erythema nodosum leprosum, a condition for which it eventually was approved by the United States Food and Drug Administration in 1998. In an animal model of neuropathic pain (chronic constriction injury), thalidomide was shown to reduce both mechanical allodynia and thermal hyperalgesia.Recent studies documented the analgesic efficacy of thalidomide in treating painful mucocutaneous aphthous ulcers associated with HIV syndrome and Behcet's disease.However, to date there are no recent clinical trials that are specifically designed to explore the analgesic potential of thalidomide.In view of the current basic research and clinical findings,we suggest to investigate the potential benefits of thalidomide in severe pain conditions that respond poorly to common pain management approaches such as neuropathic pain, postherpetic neuralgia, or central pain phenomena.Because its mechanism of action is distinct from that of other drugs such as steroids, thalidomide offers the possibility of a combined treatment with other agents with nonoverlapping toxicities.We conclude that thalidomide, when used properly,may enrich the therapeutic regimen in the management of some pain-related conditions.     

Optimal treatment for the technically resectable squamous cell carcinoma of the supraglottic larynx.

The charts of 431 patients with squamous cell carcinoma of the supraglottic larynx observed at the M. D. Anderson Hospital between January, 1954, and June, 1971, were analyzed. This study is concerned with those patients who had a technically resectable lesion. Emphasis is directed to the analysis of the effectiveness of primary irradiation instead of partial laryngectomy for those lesions which are technically suitable for a partial resection and to define the groups of patients which are best treated by combining surgery and planned postoperative irradiation. One hundred forty-seven patients with T₁ and T₂ lesions, selected exophytic T₃ lesions of the suprahyoid epiglottis and aryepiglottic folds and some selected exophytic T₄ lesions of the suprahyoid epiglottis received irradiation for their laryngeal lesion. A satisfactory control of the laryngeal disease has been obtained with preservation of a normal voice ranging from 88.5 percent for T¹ lesions to 60 percent for T₄ lesions. Comparing the groups of patients who had surgery alone or postoperative irradiation an NED rate of 63 percent was found in the latter group which is clearly superior to the 37 percent found in the surgery only group. There is no difference for the five-year NED rates, because the patients who had surgery and postoperative irradiation had more advanced neck disease which is a cause for distant metastases. The incidence of recurrences above the clavicles is clearly less in the patients having had surgery and postoperative irradiation than in those who had surgery alone. Correlating in the two groups, surgery only and surgery followed by planned irradiation, the surgical staging of the neck metastases with recurrences above the clavicles within 24 months after treatment, it was found that the planned combined treatment has reduced the recurrence rate from 45 percent to 15 percent in the N₂ and N₃ patients. Postoperative irradiation should be given routinely after resection for all T₄ lesions and for any T₃ lesion which extends to the pharyngeal wall(s), vallecula, base of tongue, and pyriform sinus. Postoperative irradiation should also be given for any patient whose nodal classification is greater than N₁. Irradiation should be given within six weeks (preferably three to four weeks) after the surgical procedure. To achieve this goal, the operation need only remove grossly detectable disease.