不同肌松药预注对顺式阿曲库铵起效时间的影响

目的研究罗库溴铵、维库溴铵、阿曲库铵及自身预注对顺式阿曲库铵起效时间和插管条件的影响。方法将70例择期手术患者随机分成Ⅰ—Ⅴ组各14例,麻醉诱导用咪达唑仑、丙泊酚和芬太尼。Ⅰ～Ⅳ组分别预注罗库溴铵0．06mg／kg、维库溴铵0．01mg／kg、阿曲库铵0．05mg/kg、顺苯磺酸阿曲库铵0．01mg／kg,Ⅴ组静注顺苯磺酸阿曲库铵0．1mg／kg;3min后Ⅰ-Ⅳ组静注顺苯磺酸阿曲库铵0．09mg／kg。观察插管量后的起效时间和气管插管条件。结果I～Ⅳ组的起效时间分别为（5．6±1．3）、（5．8±1．4）、（5．2±1．2）和（6．3±1．1）min,与Ⅴ组相比明显缩短（P〈0．05）。结论预注罗库溴铵、维库溴铵、阿曲库铵及自身预注都能缩短顺式阿曲库铵的起效时间,改善插管条件。     

七氟烷在小儿支气管异物取出术麻醉中的应用观察

目的观察小儿支气管异物取出术中吸入七氟烷麻醉的效果。方法 60例行支气管镜下异物取出术的患儿,随机分为七氟烷组（S组）和γ-羟丁酸钠组（γ组）。γ组患儿静注γ-羟丁酸钠80 mg/kg麻醉诱导,然后视情况分次给予氯胺酮。S组患儿采用面罩法吸入6.0%七氟烷行快速诱导,置镜后视手术情况予2%～3%七氟烷经支气管镜侧孔吸入。记录并比较两组患者入室时（T1）、诱导后（T2）、置镜后（T3）、术毕时（T4）及术后苏醒时（T5）的脉搏血氧饱和度（SpO2）、心率（HR）、呼吸频率（RR）及置镜条件,术中屏气呛咳、诱导苏醒时间,术后恶心呕吐、躁动发生情况。结果两组患儿均成功施行支气管镜下异物取出术。两组患者手术过程中呼吸循环稳定,T3时S组SpO2为96.7%±1.9%,与γ组的91.8%±2.9%相比,P〈0.05。S组下颌紧张、挑喉困难2例,术中呛咳屏气3例、术后舌后坠1例、苏醒期躁动10例、术后恶心呕吐2例,γ组分别为3、11、4、6、6例。S组术中呛咳屏气、术后舌后坠发生率低于γ组（P均〈0.05）,苏醒期躁动、术后恶心呕吐发生率高于γ组（P均〈0.05）。S组麻醉诱导时间为（1.8±0.3）min,苏醒时间为（10.5±3.2）min,与γ组的（4.1±0.6）min、（44.3±17.0）min相比,P均〈0.01。结论七氟烷吸入用于小儿支气管异物取出术麻醉,诱导及苏醒时间短,麻醉平稳,效果满意。     

预注罗库溴铵、顺式阿曲库铵对顺式阿曲库铵快速诱导气管插管时间的影响

目的观察预注罗库溴铵、顺式阿曲库铵对顺式阿曲库铵快速诱导气管插管时间的影响。方法选取行开腹手术的患者140例,随机分为7组。C0组为对照组,预注生理盐水3 ml。C1、C2、C3组分别预注0.005、0.01、0.015 mg/kg顺式阿曲库铵。R1、R2、R3组分别预注0.03、0.06、0.09 mg/kg罗库溴铵。3min后行常规全麻诱导:C1、R1组用顺式阿曲库铵0.145 mg/kg,C2、R2组用顺式阿曲库铵0.140 mg/kg,C3、R3组用顺式阿曲库铵0.135 mg/kg。术中采用丙泊酚4.0～6.0μg/ml靶控输注、芬太尼0.05～0.1 mg/次间断给药。分别记录各组插管时间。结果与C0组相比,C1、C2、C3、R1、R2、R3组插管时间缩短(P均<0.05)。结论预注顺式阿曲库铵或罗库溴铵可缩短顺式阿曲库铵快速诱导气管插管时间。     

右美托咪定滴鼻镇静用于先天性心脏病患儿介入封堵手术的研究

目的:探讨先天性心脏病患儿介入封堵手术应用右美托咪定术前滴鼻镇静,再复合静脉麻醉对围术期影响。方法:选取行介入封堵手术的先天性心脏病患儿60例,随机分成滴鼻组(N组)和对照组(B组)。麻醉诱导前30 min N组给予右美托咪定1.5μg/kg滴鼻镇静,B组给予等量0.9%氯化钠液。记录滴鼻即刻、滴鼻后10 min、滴鼻后30 min、手术开始时及手术结束后10 min患儿的MAP、HR;镇静程度评分;手术时间、苏醒时间及丙泊酚的总用量;术后10 min、术后30 min及术后60 min患儿麻醉苏醒期躁动评分;不良反应的发生率。结果:术中N组丙泊酚用量低于B组(P0.05)。两组在各时间点HR,MAP差异无统计学意义(P0.05)。N组患儿与家长分离时镇静评分高于B组(P0.05)。N组在术后10 min,30 min的躁动评分均低于B组(P0.05)。结论:先天性心脏病患儿介入封堵手术应用右美托咪定术前滴鼻镇静,再复合静脉麻醉可减轻患儿术前焦虑,增强麻醉效果,减少术中丙泊酚的用量,同时可减轻小儿术后躁动,使苏醒过程更加平稳。     

无肌松丙泊酚瑞芬太尼全凭静脉麻醉在耳鼻喉手术中的应用

将100例ASA Ⅰ～Ⅱ级择期行耳鼻喉手术患者,随机分为两组,各50例.无肌松组 丙泊酚(2 mg/kg)、瑞芬太尼(1.5 μg/kg)行麻醉诱导,丙泊酚[45～50 ug/(kg·min)]、瑞芬太尼[0.3～0.5 μg/(kg·min)]进行麻醉维持.对照组采用常用麻醉方法, 丙泊酚(2 mg/kg)、瑞芬太尼(1 μg/kg)、维库溴铵(0.1 mg/kg)进行麻醉诱导,丙泊酚[50～75 μg/(kg·min)],瑞芬太尼[0.15～0.2 μg/(kg·min)]进行麻醉维持,术中间断给予维库溴铵(0.04 mg/kg),维持足够肌松.观察麻醉诱导时气管插管条件,术中胸肺顺应性,麻醉停药后各项苏醒指标, 两组麻醉诱导后气管插管条件相同,术中胸肺顺应性相似,麻醉后无肌松组苏醒各项指标显著加快(P＜0.01). 认为无肌松下丙泊酚-瑞芬太尼全凭静脉麻醉用于耳鼻喉手术,可提供良好气管插管条件,麻醉维持平稳,患者无体动反应,麻醉后苏醒快.     

喉罩全麻在婴儿纤支镜气管支架置入术中的应用

目的 评价将喉罩全麻应用于婴儿纤支镜气管支架置入术的临床效果.方法 选择15例气管发育异常性狭窄需行纤支镜气管支架置入术的患儿,采用顺阿曲库铵0.2 mg/kg、瑞芬太尼0.5 μg/kg、丙泊酚2 mg/kg静脉诱导后置入喉罩,外接麻醉机控制呼吸,术中持续泵入瑞芬太尼0.5 μg/（kg·min）、丙泊酚10 mg/（kg·h）维持麻醉.术中持续监测心率（HR）、平均动脉血压（MAP）、经皮血氧饱和度（SpO2）、呼末二氧化碳分压（PET CO2）、麻醉深度监测（BIS）等.结果 患儿均一次成功置入喉罩,术中球囊扩张气道时及放置支架时,SpO2均有不同程度下降;3例SpO2低于90％者暂停手术操作,把纤支镜退出声门外,手控通气后SpO2回升至100％再次进镜顺利完成手术,气管支架置入均1次成功.患儿均在停药30 min内清醒并拔除喉罩,术中、术后无不良反应,恢复良好.结论 喉罩全麻用于婴儿纤支镜气管支架置入术,术中呼吸可控,并发症少;手术操作方便,成功率高,麻醉效果满意.     

罗库溴铵和顺式阿曲库铵用于全麻诱导的起效时间和插管条件探讨

目的 评价两种不同剂量罗库溴铵和顺式阿曲库铵用于全麻诱导气管插管时的起效时间和插管条件.方法 90例择期行全麻手术患者(ASA分级Ⅰ或Ⅱ级)随机分为3组各30例:罗库溴铵0.9 mg/kg组(Ⅰ组),罗库溴铵0.6 mg/kg组(Ⅱ组)和顺式阿曲库铵0.15 mg/kg组(Ⅲ组).Ⅰ、Ⅱ、Ⅲ组均在5 s内分别静推罗库溴铵0.9mg/kg、罗库溴铵0.6 mg/kg和顺式阿曲库铵0.15 mg/kg,记录从推药后(T1)由100％到0的时间(起效时间),当T1为0％时气管插管,评估气管插管条件.结果 Ⅰ组、Ⅱ组和Ⅲ组的起效时间分别为(70±16)、(90 ±21)、(226±47)s,两两比较,P均＜0.0l;三组患者的声门暴露评级差异无统计学意义(P＞0.05),三组的气管插管条件差异无统计学意义(P＞0.05).结论 0.9 mg/kg剂量的罗库溴铵诱导起效时间快于0.6 mg/kg罗库溴铵和0.15 mg/kg的顺式阿曲库铵;当诱导后T1为0％时,三组的声门暴露评级和气管插管条件无明显差异.     

丙泊酚联合顺式阿曲库铵用于小儿纤支镜检查的肌松效果观察

目的观察丙泊酚联合顺式阿曲库铵在喉罩通气全麻下用于小儿纤支镜检查的肌松效果。方法回顾性分析2013-01~2014-12住院行纤支镜检查的68例儿科患者的临床资料,根据麻醉用药的不同分为丙泊酚联合顺式阿曲库铵组(A组)36例和丙泊酚联合氯胺酮组(B组)32例,比较两组的麻醉起效时间、阻滞维持时间、临床作用时间、体内作用时间以及肌松恢复指数。结果 A组麻醉起效时间明显比B组短,而A组的阻滞维持时间、临床作用时间、体内作用时间和肌松恢复指数均比B组高,两组比较差异均有统计学意义(P均0.01)。结论丙泊酚联合顺式阿曲库铵应用于喉罩通气全麻下小儿纤支镜检查能取得比丙泊酚联合氯胺酮更好的肌松效果,值得推广。     

持续泵注与间断静注顺式阿曲库铵的药效学比较

目的比较顺式阿曲库铵持续泵注与间断静注的药效学特点,探讨其最佳给药方式。方法 30例ASAⅠ～Ⅱ级,无神经肌肉疾患,拟在全麻下行择期手术的女性患者,随机分成顺式阿曲库铵持续泵注组(Ⅰ组,15例)和间断静注组(Ⅱ组,15例),采用TOF刺激方式,监测拇内收肌的收缩反应。记录2组患者神经肌肉阻滞的维持时间及肌松恢复过程,并记录顺式阿曲库铵的维持用药量。应用静脉麻醉诱导,七氟烷吸入麻醉维持。全部病例在肌松恢复期均未予以拮抗,使其在安静状态下自然恢复。当TOF恢复至T1/Tc≥75%时,结束肌松监测,呼吸恢复满意后拔管。结果Ⅰ组肌松维持用药量为(0.78±0.15)μg/(kg.min),Ⅱ组为(1.09±0.33)μg/(kg.min),P<0.05。2组患者肌松维持时间差异无统计学意义(P>0.05)。停止泵注后Ⅰ组的恢复指数为(13.13±3.36)min,Ⅱ组为(14.38±4.48)min,P>0.05,但Ⅰ组快于Ⅱ组。结论持续输注顺式阿曲库铵可维持恒定的肌松水平且单位时间内较间断静注节省肌松药用量,Ⅰ组停止泵注后恢复指数较Ⅱ组稍快。     

七氟醚与丙泊酚麻醉对老年全麻患者术后认知功能的影响

目的探讨七氟醚与丙泊酚对老年全麻患者术后认知功能的影响。方法选取择期手术需行全麻手术的患者80例,ASA分级Ⅰ^Ⅱ级,随机分为七氟醚组与丙泊酚组各40例,均以咪达唑仑0.04Ⅱ级,随机分为七氟醚组与丙泊酚组各40例,均以咪达唑仑0.04⁰.06 mg/kg、芬太尼20.06 mg/kg、芬太尼2⁴μg/kg及顺式阿曲库铵0.154μg/kg及顺式阿曲库铵0.15⁰.2 mg/kg进行麻醉诱导,七氟醚组采取1%0.2 mg/kg进行麻醉诱导,七氟醚组采取1%¹.5%七氟醚、丙泊酚组采取1%丙泊酚麻醉维持。观察患者平均动脉压(MAP)、血氧饱和度(SPO2)、心电图(ECG)、呼气末二氧化碳分压(PETCO2)、心率(HR)、尿量等生理指标,以简易智能状态评分(MMSE)评价认知功能,苏醒质量,检测血清S100β蛋白含量。结果 (1)两组患者手术时间、术中MAP、SPO2、PETCO2、HR比较差异无统计学意义(P>0.05)。(2)术前MMSE评分两组之间差异无统计学意义(P>0.05),术后1 h MMSE评分最低,后逐渐升高,术后1、3、6、24 h两组比较差异有统计学意义(P<0.05),治疗前后两组组内比较差异有统计学意义(P<0.05)。(3)七氟醚组自主呼吸时间、呼之唤醒时间、拔管时间明显长于丙泊酚组(P<0.05)。(4)S100β蛋白含量术后明显升高,手术前后组内比较差异显著(P<0.05),治疗后S100β蛋白含量组间比较差异显著(P<0.05)。结论七氟醚及丙泊酚均会引起老年全麻患者术后认知功能下降,丙泊酚相对于七氟醚对认知功能的影响小,术后恢复更快。     

胰岛素瘤的解剖分布特点分析

目的胰岛素瘤是最常见的胰腺神经内分泌肿瘤，因其临床表现多样，导致诊断困难。影像学诊断尤其是超声内镜(EUS)在胰岛素瘤的诊断中起着重要作用，拥有较高的敏感性和特异性。本研究拟通过明确胰岛素瘤的解剖分布特点，以期有助于提高影像学的诊断准确率和降低漏诊率，尤其是在教育和培训实践中对于EUS的学习者更具有指导价值。 方法回顾性分析解放军总医院第一医学中心病案资料数据库1993年1月至2019年11月经外科手术、病理确诊为胰岛素瘤的患者的临床资料，检索方法采取搜索术后病理诊断为"胰岛素瘤"的病例，通过查阅病例的方法，提取出胰岛素瘤的大小和解剖分布等数据，进一步分析其特点。 结果共检索到确诊为胰岛素瘤的患者116例，其中，男45例、女71例，年龄13～76岁，平均年龄(44.4±14.85)岁。胰岛素瘤单发110例(94.8%)、多发6例(5.2%)。位置分布：头颈部46例(39.7%)，单发45例、多发1例；体尾部68例(58.6%)，单发65例、多发3例；全胰腺多发2例(1.7%)。病变大小特点：最大径0.4～3.4 cm，平均大小(1.53±0.58)cm。≤1 cm 29例、>1 cm而≤1.5 cm41例、>1.5 cm而≤2.0 cm28例，≤3 cm 15例，>3 cm 3例。年龄与肿瘤的大小相关，≤44岁患者肿瘤平均大小为(1.36±0.51)cm、>44岁患者肿瘤平均大小为(1.70±0.60)cm，P<0.05。头颈部的肿瘤大于体尾部的肿瘤，头颈部肿瘤平均大小(1.66±0.63)cm，体尾部(1.42±0.52)cm，P<0.05。 结论胰岛素瘤在胰腺体尾部较头颈部更好发；绝大多数单发，但可以全胰腺多发；多数小于1.5 cm，肿瘤的大小与患者年龄和肿瘤的解剖分布相关。     

Pathogenesis of carcinoma of the papilla of Vater

Most adenomas and carcinomas of the small intestine and extrahepatic bile ducts arise in the region of the papilla of Vater. In familial adenomatous polyposis (FAP) it is the main location for carcinomas after proctocolectomy. In many cases symptoms due to stenosis lead to diagnosis at an early tumor stage. In about 80%, curative intended resection is possible. Operability is the most relevant prognostic factor. Most ampullary carcinomas resp. carcinomas of the papilla of Vater develop from adenomatous or flat dysplastic precursor lesions. They can be sited in the ampulloduodenal part of the papilla of Vater, which is lined by intestinal mucosa. They also can develop in deeper parts of the ampulla, which are lined by pancreaticobiliary duct mucosa. Intestinal-type adenocarcinoma and pancreaticobiliary-type adenocarcinoma represent the main histological types of ampullary carcinoma. Furthermore, there exist unusual types and undifferentiated carcinomas. Many carcinomas of intestinal type express the immunohistochemical marker profile of intestinal mucosa (keratin 7?, keratin 20+, MUC2+). Carcinomas of pancreaticobiliary type usually show the immunohistochemical profile of pancreaticobiliary duct mucosa (keratin 7+, keratin 20?, MUC2?). Even poorly differentiated carcinomas, as well as unusual histological types, may conserve the marker profile of the mucosa they developed from. These findings underline the concept of histogenetically different carcinomas of the papilla of Vater which develop either from intestinal- or from pancreaticobiliary-type mucosa of the papilla of Vater. Molecular alterations in ampullary carcinomas are similar to those of colorectal as well as pancreatic carcinomas, although they appear at different frequencies. In future studies, molecular alterations in ampullary carcinomas should be correlated closely with the different histologic tumor types. Consequently, the histologic classification should reflect the histogenesis of ampullary tumors from the two different types of papillary mucosa.     

Demonstration of the mechanism of action of biguanides

Summary Palmitic acid oxidation in rat diaphragm homogenate is depressed by biguanide concentrations that are still incapable of inhibiting oxidative phosphorylation. Glucose oxidation is not directly effected by the same biguanide concentrations: however, the inhibitory effect of palmitic acid on glucose oxidation is partly removed by biguanides. Inhibition of fatty acid oxidation, which accounts for most of the metabolic effects caused by these drugs, can be regarded as the fundamental mechanism of action of biguanides. There is some evidence suggesting that these drugs might interact with carnitine, thus preventing long-chain fatty acids from being transported across the mitochondrial membrane to the site of oxidation. Traduzione a cura degli AA.     

Lack of correlation of degree of villous atrophy with severity of clinical presentation of coeliac disease

BACKGROUND AND AIM: Both the clinical presentation and the degree of mucosal damage in coeliac disease vary greatly. In view of conflicting information as to whether the mode of presentation correlates with the degree of villous atrophy, we reviewed a large cohort of patients with coeliac disease. PATIENTS AND METHODS: We correlated mode of presentation (classical, diarrhoea predominant or atypical/silent) with histology of duodenal biopsies and examined their trends over time. RESULTS: The cohort consisted of 499 adults, mean age 44.1 years, 68% females. The majority had silent coeliac disease (56%) and total villous atrophy (65%). There was no correlation of mode of presentation with the degree of villous atrophy (p=0.25). Sixty-eight percent of females and 58% of males had a severe villous atrophy (p=0.052). There was a significant trend over time for a greater proportion of patients presenting as atypical/silent coeliac disease and having partial villous atrophy, though the majority still had total villous atrophy. CONCLUSIONS: Among our patients the degree of villous atrophy in duodenal biopsies did not correlate with the mode of presentation, indicating that factors other than the degree of villous atrophy must account for diarrhoea in coeliac disease.     

血吸虫童虫生长发育及其机制的研究进展

血吸虫童虫是宿主免疫系统攻击的重要靶标,包括皮肤型、肺型和肝门型童虫。宿主分子对童虫生长发育具有重要作用。童虫生长发育机制包括免疫调节、信号转导、性别发育及凋亡等。肌动蛋白、组织蛋白酶、烯醇化酶和葡萄糖基转移酶等分子为血吸虫童虫生长发育的重要分子。本文对血吸虫童虫生长发育及其机制的研究进展做一综述。     

124例耐多药结核分枝杆菌基因突变特征分析

目的对临床分离的耐多药结核分枝杆菌相关基因的突变特征进行分析。方法对124例耐多药结核分枝杆菌以及50株敏感株的耐药相关基因(包括异烟肼inh A、kat G、oxyR-ahp C间隔区以及利福平rpo B)进行序列测定,分析其基因突变情况。结果异烟肼耐药inh A基因突变率为14.5%;kat G基因突变率为70.2%(87/124),主要位于315位;oxyR-ahp C间隔区突变率为15.3%;inh A、kat G两种基因同时突变率75.0%,三种基因同时突变率为89.5%。利福平rpo B基因突变的检出率高达95.2%,突变主要发生在531、526、516位点。结论我省耐多药菌异烟肼耐药相关基因最常见突变为kat G 315、inh A C-T(-15)、axyR-ahp C间隔区(-10)C-T,利福平为rpo B531、526、516。结合MDR-TB耐药相关基因的特征分析,可以建立一种快速、准确、特异的适合于我省的检测结核菌耐多药性的新方法。     

氯硝柳胺悬浮剂的毒性评价

目的评价氯硝柳胺悬浮剂的毒性，为现场大规模应用灭螺提供依据。方法按照中华人民共和国国家标准GB 15670-1995《农药登记毒理学试验方法》和鱼类毒性试验方法进行。结果经口、经皮肤的LDso雌、雄性大鼠均>5 000 mg/kg，经呼吸道的LCso雌、雄性大鼠均>5 000mg/m3，该药经口、经皮肤、经呼吸道毒性均属微毒类药物；兔眼用药后，观察期内无不良反应，对眼无刺激性；皮肤用药后对皮肤无刺激性。与氯硝柳胺原药、氯硝柳胺乙醇胺盐原药和氯硝柳胺乙醇胺盐可湿性粉剂相比，氯硝柳胺悬浮剂对鱼急性毒性最低。结论氯硝柳胺悬浮剂属微毒类药物，对鱼的毒性低于其乙醇胺盐可湿性粉剂，适合于现场应用。     

Assessment of quality of life of parents of children with juvenile chronic arthritis

The aim of the study was to assess the quality of life (QOL) and the psychological status of parents of children with juvenile chronic arthritis (JCA). The QOL, anxiety and depression of the parents of 28 children with JCA were evaluated and compared to those of the parents of 28 healthy children. Mothers of JCA children and mothers of healthy children reported similar QOL. The reported anxiety and depression levels were similar for mothers and fathers in both groups. The parents of children with pauciarticular-type JCA reported lower QOL and higher levels of anxiety and depression than the parents of children with other types, namely polyarticular and systemic JCA. These findings may be explained by the fact that the pauciarticular patients had shorter disease duration and were less frequently seen in the outpatient clinic. The QOL of mothers of children with JCA was found to be slightly impaired in the group of children with pauciarticular JCA. Future larger studies are needed to confirm these results, as the number of subjects in the three groups was rather low. Received: 26 September 2001 / Accepted: 8 February 2002     

Numerical Simulation of the Effect of Rate of Change of Glucose on Measurement Error of Continuous Glucose Monitors

Background

A 5-day in-patient study designed to assess the accuracy of the FreeStyle Navigator® Continuous Glucose Monitoring System revealed that the level of accuracy of the continuous sensor measurements was dependent on the rate of glucose change. When the absolute rate of change was less than 1 mg•dl⁻¹•min⁻¹ (75% of the time), the median absolute relative difference (ARD) was 8.5%, with 85% of all points falling within the A zone of the Clarke error grid. When the absolute rate of change was greater than 2 mg•dl⁻¹•min⁻¹ (8% of the time), the median ARD was 17.5%, with 59% of all points falling within the Clarke A zone.

Method

Numerical simulations were performed to investigate effects of the rate of change of glucose on sensor measurement error. This approach enabled physiologically relevant distributions of glucose values to be reordered to explore the effect of different glucose rate-of-change distributions on apparent sensor accuracy.

Results

The physiological lag between blood and interstitial fluid glucose levels is sufficient to account for the observed difference in sensor accuracy between periods of stable glucose and periods of rapidly changing glucose.

Conclusions

The role of physiological lag on the apparent decrease in sensor accuracy at high glucose rates of change has implications for clinical study design, regulatory review of continuous glucose sensors, and development of performance standards for this new technology. This work demonstrates the difficulty in comparing accuracy measures between different clinical studies and highlights the need for studies to include both relevant glucose distributions and relevant glucose rate-of-change distributions.     

Study of constancy of hydrogen-consuming flora of human colon

The constancy of the hydrogen consuming flora of the human colon was studied in 15 healthy subjects via two measurements obtained 18 to 36 months apart. Hydrogen disappearance rate and the major products of H₂-consuming bacteria, methane and sulfide, were measured during incubation of fecal homogenates with excess hydrogen and sulfate. In 11/15, the hydrogen consumption rate and the predominant hydrogen-consuming pathway (methanogenesis, sulfate reduction, or neither) remained constant. However, major shifts in these pathways were observed in four subjects, with two losing and two gaining the ability to produce methane. Methanogenesis was associated with the highest hydrogen consumption rate. This study demonstrates that clinically unrecognizable, major alterations of the colonic flora occur in healthy subjects. Understanding of the factors responsible for these alterations might allow for therapeutic manipulation of the colonic flora.Supported in part by the Department of Veterans Affairs and NIDDKD RO1 DK 13309-25.