ALFENTANIL PLASMA CONCENTRATION v. EFFECT RELATIONSHIPS IN CARDIAC SURGICAL PATIENTS

Effects of alfentanil, preceded by lorazepam, on suppressionof haemodynamic and somatic responses to noxious stimuli wasstudied in patients undergoing CABG. Plasma concentration ofalfentanil, somatic and haemodynamic responses were measuredat loss of consciousness, tracheal intubation, sternotomy andduring multiple applications of electrocoagulation. Additionalalfentanil was administered i.v. to control unwanted responses.Study 1 (six patients): lorazepam 0.08 mg kg^–1 by mouth1–2 h before operation, alfentanil priming infusion (60µg kg^–1 min^–1 for 10 min) followed by maintenanceinfusion (4.5 µg kg^–1 min^–1). With mean plasmaalfentanil 1178 (SEM 54) ng ml^–1, two patients requiredsupplementary alfentanil to suppress somatic motor responses;one patient required nitroglycerin to control an increase inarterial pressure which was unresponsive to additional alfentanilfollowing sternotomy. Study 2 (13 patients): lorazepam 0.04mg kg^–1 by mouth as premedication; one of three maintenanceinfusion rates of alfentanil: 5.4 (n=4), 6.6 (n=5), or 7.8 (n=4)µg kg^–1 min^–1, each preceded by a proportionalpriming infusion. With plasma alfentanil 2181 (62)ng ml^–1,somatic motor responses requiring additional alfentanil occurredin nine patients; haemodynamic responses in four of seven patientstested could not be controlled by alfentanil. The highest plasmaconcentration of alfentanil to prevent response to a stimulusother than tracheal intubation was different between the twostudies (P<0.05). We conclude that alfentanil alone is insufficientto suppress haemodynamic and somatic motor responses to noxiousstimulation during CABG and that the role of premedication issignificant. *Department of Anesthesia, Bowman-Gray School of Medicine Winston-Salem,NC 27103, U.S.A. 2114 de Mayo Road, Del Mar, Ca. 92014, U.S.A.     

儿童运动障碍治疗展望

目的：儿童运动障碍领域目前仍有许多问题存在争论,其主要原因是因为缺少确切有效的治疗方法或药物,最近的一些研究介绍了治疗方法及其进展.资料来源：应用计算机进入湘雅医学院图书馆（http：www.xysm.net）检索2000-01/2004-12期间与儿童运动障碍治疗相关的文献,检索词为“movement disorders;pediatric;treatment”,并限定文献语言种类为“English”.资料选择：按儿童运动障碍治疗进展对相关文献进行提炼,纳入与儿童运动障碍治疗相关文献,不排除未随机试验以及盲法对照的文献.资料提炼：共收集与儿童运动障碍治疗相关文献196篇,进步查看全文,筛除明显重复或太陈旧及综述类文献,纳入15篇文献进行综述资料综合：传统治疗儿童运动障碍的方法主要有神经活性药物、抗微生物药、生物制品、除去疗法及神经保护剂等.新疗法有抑制细胞凋亡、载体疗法、对流转运、异生物素生物转化等.神经外科治疗新方法包括立体定向脑毁损术、深部脑刺激和神经切断术.基因疗法和染色体工程及干细胞移植也取得了很多进展,同时治疗中存在一些困惑,例如新的或更广泛的运动障碍的表现、无诊断的治疗和难治性运动障碍的选择等.结论：近几年儿童运动障碍治疗有所进展,治疗的主干是口服药物,但在分子生物学和干细胞移植方面的进展为既往不能治疗的患儿提供了期望.     

Therapy Assessment for Sustained Ventricular Tachyarrhythmias: How Many Electropharmacological Tests are Appropriate?

Surgery, implantable devices or catheter ablations offer therapeutic choices for the treatment of malignant ventricular tachyarrhythmias (VT) resistant to antiarrhythmic drugs. The number of electropharmacological (EP) tests that should precede consideration of a nonpharmacological therapy has not been defined. We performed serial EP tests in 94 patients with inducible sustained VT until an effective drug was identified or all available drugs had failed to suppress VT induction. With up to 11 tests in individual patients, suppression of VT inducibility was finally achieved in 66 patients (70%). In 47 of these 66 patients (70%), only one or two tests were necessary to identify an effective regimen. However, in 40%, 28%, 18%, and 9% of the patients still inducible after 2, 3, 4, and 5 drug tests, respectively, an effective agent could be identified during subsequent tests. No critical number of unsuccessful EP tests clearly separated responders and nonresponders to medical therapy. During follow-up (34 +/- 11 months), 14 patients placed on antiarrhythmic drugs predicted to be effective had symptomatic VT recurrence. VT recurrence was unrelated to the type or the number of unsuccessful EP tests preceding identification of the prescribed drug. Extensive EP testing with all available agents might therefore be worthwhile in selected patients. An "appropriate" number of EP studies has to be determined individually for each patient, based on the chance of finding an effective drug during subsequent studies and the risk and benefit of the therapeutic choices.     

Massive accidental overdose of hydroxyurea in a young child with sickle cell anemia

The Pediatric Hydroxyurea Phase III Clinical Trial (BABY HUG) confirmed safety and efficacy of hydroxyurea therapy for infants with sickle cell anemia. Treatment was associated with reduction in rates of pain, acute chest syndrome, hospitalizations, and blood transfusions; improved hematologic values; and, perhaps, preservation of organ function. During the study, a 2-year-old ingested at one time an entire 35-day supply of hydroxyurea (612 mg/kg body weight). Despite a serum level of 7,756 μM 4 hours post-ingestion, the only toxicity was transient mild myelosuppression. With wider usage of hydroxyurea anticipated, conservative management of future overdoses seems reasonable (ClinicalTrials.gov NCT00006400).