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.     

Procalcitonin's role in the sepsis cascade. Is procalcitonin a sepsis marker or mediator?

PCT is a 116-amino acid polypeptide glycoprotein that is ubiquitously expressed from various extrathyroid neuroendocrine tissues during bacterial infection. PCT was shown to closely correlate with the severity of sepsis. PCT synthesis is probably induced by tumor necrosis factor-alpha (TNFalpha) or interleukin-6 (IL-6), the primary cytokines in the inflammatory cascade, as they always peak before PCT. In healthy and septic animals, PCT injection did not initiate or enhance the production of TNFalpha, while TNFalpha injection induced a 25-fold massive and sustained PCT increase. This indicates that PCT release is not a 'proximal' but rather an 'intermediary' event in the sepsis cascade that requires a 'primed' inflammatory background to exert its effect. PCT, a prohormone that follows a cytokine-like expression pathway, was coined a 'hormokine' to signify its cytokine-like host-response. In our center, over a period of 2 years, we investigated subsets of postoperative ICU patients with sepsis. The area under the Receiver Operating Characteristic curve for PCT's prediction of survival outcome demonstrated a very high discriminative power of 0.90 from day 6, with a cut-off value of 3.2 ng mL(-1) PCT concentration. Interestingly, in our study, PCT declined a few days before a lethal outcome. This ominous sign clearly demonstrates that patients with poor prognosis would manifest, at a certain stage, a decrease in their ability to mount an effective response to sepsis.     

Influence of acute normovolaemic haemodilution on the dose-response relationship and time course of action of cisatracurium besylate

BACKGROUND: Acute normovolaemic haemodilution (ANH) is an efficacious bloodconservation strategy aiming at avoiding allogeneic blood transfusion.ANH was shown to increase the potency of vecuronium, atracurium,and rocuronium. The aim of our study was to investigate whethercisatracurium potency is altered with ANH. METHODS: Using the Relaxometer mechanomyograph, we compared cisatracuriumdose–response relationship and time course of action in60 patients randomly allocated to the ANH or control groups.Patients in each group were randomly allocated to receive oneof three cisatracurium doses (30, 40, 50 µg kg^–1)followed by a second supplemental dose to reach a total of 100 µg kg^–1. RESULTS: ANH did not result in a significant shift in cisatracurium logdose–probit dose–response curve. There was no significantdifference in mean (95% confidence intervals) ED₅₀, ED₉₀, andED₉₅ (effective doses required for 50, 90, and 95% first twitchdepression) between the ANH group [29.5 (27–32), 50.4(47.4–53.4), 58.7 (55.3–62) µg kg^–1]and the control group [28.2 (25.3–31), 47.6 (44.9–50.3),55.3 (52.5–58.1) µg kg^–1], whereasthere was no difference in mean (SD) Dur₂₅ and Dur_0.8 (timeuntil 25% first twitch and 0.8 train-of-four ratio recoveries)between the ANH group [40.8 (5.9), 64.7 (8.4) min] and the controlgroup [42.2 (7.6), 66.5 (10.7) min]. CONCLUSIONS: Our results demonstrated that unlike other previously reportedneuromuscular blocking drugs, ANH did not alter cisatracuriumpotency. Thus, cisatracurium would be the neuromuscular blockingdrug of choice in patients who undergo surgery with ANH, asno dose adjustments are required.     

Histological changes following high-dose methotrexate and cisplatinum administration and the influence of dosage scheduling

Histological changes were studied in experimental animals following the intraperitoneal administration of high-dose cisplatin with or without high-dose methotrexate and citrovorum factor. There were pronounced renal toxicities with high-dose (10 mg/kg) cisplatin, particularly involving distal tubules with glomerular congestion. However, lower toxicities were noted with reduced dosage of cisplatin (5 mg/kg) and especially if given once as a single bolus injection instead of a 5-day regimen. Renal and hepatic toxicities were marked with concomitant methotrexate administration leading to hemorrhagic diathesis and shorter survival. However, toxicities were relatively reduced when cisplatin was given as a single bolus injection instead of a 5-day divided course. Such information may prove helpful in future planning of combination chemotherapy in patients with malignancies using these two agents.     

不同地域患者罗库溴铵药效学的比较多中心研究

目的比较中国、奥地利和美国3个不同地域的当地患者罗库溴铵作用的量效关系和时效关系。方法选择中国大连、美国英格伍德、奥地利格拉茨3个医学中心择期手术患者各18例,异丙酚、芬太尼静脉麻醉诱导后,累积剂量法进行药效学观察,首剂静脉注射罗库溴铵50μg/kg,起效后重复首剂静脉给药6次,再静脉注射罗库溴铵300μg,采用肌机械运动监测仪记录肌肉收缩强度,对数剂量．概率单位绘制剂量-反应曲线。比较3个地域患者罗库溴铵的ED50、ED90和ED95以及Dur25和Dur0．8。结果大连和格拉茨患者罗库溴铵的ED50、ED90和ED95均高于英格伍德患者,格拉茨患者的ED50、ED90和ED95高于大连患者（P＜0．05）;大连和格拉茨患者的Dur25和Dur0．8均短于英格伍德患者（P＜0．05）,格拉茨患者的Dur25短于大连患者（P＜0．05）,但两者Dur0．8的差异无统计学意义（P＞0．05）。结论3个地域患者罗库溴铵作用的量效关系和时效关系有明显的差别,临床用量需要考虑地域因素的影响。     

The neuromuscular transmission module versus the relaxometer mechanomyograph for neuromuscular block monitoring

The neuromuscular transmission module (M-NMT) is an integrated piezoelectric motion sensor module incorporated in the AS/3(TM) anesthesia monitor. We compared the neuromuscular block of 0.6 mg/kg rocuronium (twice the 95% effective dose) monitored by the M-NMT with that monitored by the Relaxometer mechanomyograph (MMG). The two monitors were alternately allocated to the left or right hands of 20 patients. T(1)%, the first twitch of the train-of-four (TOF), and the TOF ratio (T(4)/T(1)) were used for evaluating the neuromuscular block. There was no significant difference in the mean (min) plus minus SD onset time or time to 0.8 TOF ratio recovery measured by the M-NMT (1.5 plus/minus 0.3, 49.4 plus/minus 8.1) compared with MMG (1.8 plus/minus 0.6, 50.9 plus/minus 9.9), respectively. However, the time (min) to 25% T(1) recovery was significantly longer when monitored by the M-NMT (25.6 plus/minus 8) than by the MMG (20.2 plus/minus 6.3). During recovery from neuromuscular block, the difference between the TOF ratios measured by the two monitors showed a bias of -0.031, and the limits of agreement (bias plus/minus 1.96 SD) were -0.281 and +0.22. The M-NMT monitor could determine the time to tracheal intubation as well as full recovery from neuromuscular block, but it lagged behind the MMG in determining the time to rocuronium repeat dose administration. IMPLICATIONS:Compared with the Relaxometer mechanomyograph, the neuromuscular transmission module could equally indicate time to tracheal intubation and full recovery from 0.6 mg/kg rocuronium neuromuscular block. Its small quick-fit sensor has the advantage, in an often crowded and busy operating room, of being incorporated in the AS/3(TM) anesthesia workstation.