允许性高碳酸血症对急性肺损伤绵羊肺力学及血流动力学的影响

目的　探讨允许性高碳酸血症 (PHC)对急性肺损伤 (ALI)绵羊肺力学及血流动力学的影响。方法　观察不同潮气量 (VT)时 ,18只ALI绵羊肺气体交换、肺力学和血流动力学的改变。结果　当VT 从 16ml/kg降至 4～ 7ml/kg时 ,绵羊均出现PHC ,动脉血氧分压、氧饱和度和混合静脉血氧饱和度显著降低 (P <0 0 5 )。PHC时气道压力显著降低 (P <0 0 5 ) ,气道阻力明显增高 ;体循环和肺循环阻力指数、左心室和右心室做功指数显著增加 ,心率降低 (P <0 0 5 )。与VT16ml/kg相比 ,VT4ml/kg时心排指数 (CI)显著降低。静态肺压力 容积曲线高位转折点对应的压力为 (2 1 8± 3 2 )cmH2 O ,容积为 (10 7± 1 3)ml/kg。结论　在实施PHC时 ,只有当气道平台压 <2 0～ 2 5cmH2 O时才有可能避免肺泡过度膨胀 ,但PHC时CI降低     

应用肺动态压力-容积曲线低位转折点选择最佳呼气末正压的研究

目的探讨根据动态肺压力-容积曲线低位转折点压力(Pinf)选择急性呼吸窘迫综合征(ARDS)患者最佳呼气末正压(PEEP)的可行性.方法以8例早期ARDS患者为研究对象,测定动态肺压力-容积曲线及Pinfd.采用低流速法测定准静态肺压力-容积曲线,并确定静态肺压力-容积曲线低位转折点压力(Pinfs).调整PEEP水平,观察患者血流动力学、肺机械力学和氧代谢的变化.结果当PEEP从Pinfd-6cmH2O水平增加到Pinfd+6cmH2O时,动脉血氧分压、动脉血氧饱和度、气道平均压和气道峰压均显著增加.与Pinfd+6cmH2O比较,Pinfd-4cmH2O时的动态肺顺应性显著增高.Pinfd+6cmH2O时的心脏指数有降低趋势,Pinfd-4cmH2O时的氧输送有升高趋势.当Pinfd为(12.8±3.2)cmH2O,Pinfs为(11.0±3.2)cmH2O,两者具有正相关性(r=0.99,P《0.05).回归方程为Pinfd=1.66+1.01×Pinfs.结论当ARDS患者行机械通气治疗时,Pinfd-4cmH2O或Pinfs-2cmH2O为最佳PEEP,可获得最大氧输送.     

控制性肺膨胀治疗急性呼吸窘迫综合征家兔的最佳压力选择

目的　探讨实施控制性肺膨胀 (SI)治疗急性呼吸窘迫综合征 (ARDS)的最佳复张压力。方法　采用肺泡灌洗法建立重度ARDS家兔模型 ,以 1～ 6倍的平均气道压 (Pm)作为实施SI的压力 ,屏气时间 2 0s。在SI前、SI期间及SI后 2min和 5min监测家兔血流动力学、肺力学、肺气体交换和肺损伤指标。以改善氧合和肺容积最显著、不加重肺损伤、同时对血流动力学影响最小的压力为最佳压力。结果　SI的压力达到 3Pm 以上时 ,家兔动脉血氧分压 (PaO2 )和动脉血氧饱和度明显提高。 5Pm 和6Pm 时SI前后的PaO2 差值 (ΔPaO2 )分别为 (6 5± 40 )mmHg(1mmHg =0 133kPa)和 (5 2± 2 5 )mmHg ,显著高于 1Pm[(- 5± 4)mmHg ,P <0 0 5 ]。 5Pm SI时的动态肺顺应性增加最明显 ,达 (3 0 6± 0 2 4)ml/cmH2 O ,明显高于SI前的水平 [(1 0 9± 0 18)ml/cmH2 O ,P <0 0 5 ]。 5Pm 时SI前后肺容积改变最显著 ,达到 (4 4 0± 3 1)ml/kg,明显高于 1Pm[(8 3± 0 7)ml/kg ,P <0 0 5 ]。未实施SI的ARDS家兔肺损伤评分为 6 10± 0 77,5Pm 时的肺损伤评分显著降低 (4 4 0± 1 6 6 ,P <0 0 1)。 6Pm 时则导致肺泡过度膨胀 ,加重肺损伤。随着SI的压力增加 ,家兔的平均动脉血压显著降低。结论　重度ARDS家兔实施SI的最佳压力是 5Pm(2 5～     

高龄老年呼衰患者有创机械通气时血液动力学的影响

目的探讨高龄呼衰患者机械通气使用对血液动力学的影响。方法54例入选对象均使用有创机械通气纠正呼衰,在病情稳定时监测呼吸力学和无创心功能。设定机械通气VT按12ml/kg、10ml/kg、8ml/kg、6ml/kg,PEEP为0、5、8、10cmH2O,及为PEEPi 75%、100%、125%共28种通气状况时,高龄患者机械通气时血液动力学的变化。结果1.高龄患者在VT达≥10ml/kg时,在PEEP设定为0～10cmH2O范围内;或PEEP≥10cmH2O时,VT设定在6～12ml/kg范围内时,均可产生较高的气道峰压和吸气平台压,产生HR和CVP增高,SBP、DBP、CI和CO下降等血流动力学异常。2.同样,PEEP设定为PEEPi125%时,VT分别为每公斤体重6、8、10、12ml时,SBP、DBP、CO和CI逐渐降低,HR、CVP与VT成正相关。当VT设定为12ml/kg,PEEP为PEEPi的125%时,表现为气道峰压和吸气末平台压明显高,肺顺应性低。并出现SBP、DBP、CO和CI明显下降,HR和CVP增高等血液动力学的改变。3.若PEEP和VT同时增大时,气道峰压和吸气末平台压升高更明显,肺顺应性更低;患者的SBP、DBP、CI、CO下降更明显,HR和CVP增高幅度更大。结论通过本临床研究我们发现高龄呼衰患者有创机械通气时潮气量等于或大于10ml/kg时、PEEP等于或大于10cmH2O或为PEEPi 125%时,易出现血液动力学的影响;     

低潮气量低呼气末正压治疗急性肺创伤术后急性呼吸窘迫综合征疗效观察

目的 :探讨急性肺创伤术后并发急性呼吸窘迫综合征 (ARDS)患者的机械通气对策 ;方法 :将6 1例急性肺创伤术后并发ARDS患者随机分为A、B两组 ,A组 31例 ,采用传统机械通气模式 (VT10～ 13.5ml/kg ,PEEP 10～ 18cmH2 O) ;B组 30例 ,采用低潮气量、低呼气末正压 (VT7～ 8ml/kg ,PEEP 5～ 10cmH2 O)、许可性高碳酸血症通气 (动脉血PaCO2 10 .18± 1.14kPa ,pH 7.30±0 .0 5 )对策。通过调节同步间歇指令通气频率使两组患者的分钟通气量保持对等 (9～ 12L/min) ,对两组患者进行疗效比较。结果 :A组病死率和机械通气所致并发症发生率均明显高于B组 (P<0 .0 5或 <0 .0 1)。结论 :低VT、低PEEP机械通气对策可明显降低急性肺创伤术后并发ARDS患者的病死率。     

肺复张后呼气末正压通气不同模式对腹腔镜结直肠癌根治术肥胖患者呼吸力学和血流动力学的影响

目的探讨肺复张后呼气末正压通气(PEEP)不同模式对腹腔镜结直肠癌根治术肥胖患者呼吸力学和血流动力学的影响。方法 90例拟行腹腔镜结直肠癌根治术肥胖患者随机分为传统组、PEEP5组和PEEP10组,设置潮气量(VD)8 ml/kg,分别在肺复张后不给予PEEP、PEEP 5 cm H2O和PEEP 10 cm H2O。观察气腹建立前(T0)、气腹建立后10 min(T1)、气腹后头低足高位20 min(T2)和气腹结束(T3)时的气道峰压(Ppeak)、平台压(Pplat)、有效静态总顺应性(Cst)、气道阻力(Raw)、氧合指数(PaO_2/FiO_2)、死腔量(VD/VT)和肺内分流量。结果与传统组比较,PEEP5组和PEEP10组T1时Ppeak、Raw、VD/VT和Qs/Qt增加,Cst和PaO_2/FiO_2下降,T2和T3时VD/VT和Qs/Qt下降,PaO_2/FiO_2增加(P<0.05);与PEEP5组比较,PEEP10组T3时Ppeak、VD/VT和Qs/Qt下降,PaO_2/FiO_2增加(P<0.05)。结论肺复张后给予小VD(8 ml/kg)+PEEP可以改善腹腔镜结直肠癌根治术肥胖患者呼吸力学和血流动力学指标,且PEEP 10 cmH2O效果更优。     

肺保护与肺开放通气策略对急性呼吸窘迫综合征家兔血管外肺水的影响

目的探讨肺保护与肺开放通气策略对急性呼吸窘迫综合征(ARDS)血管外肺水(EVLWI)的影响。方法以肺泡灌洗法复制家兔ARDS模型,分为中等潮气量(VT)零呼气末正压(PEEP)组(MVZP组)、小VT零PEEP组(LVZP组)、小VT最佳PEEP组(LVBP组)和小VT最佳PEEP+控制性肺膨胀(SI)组(LVBP+SI组)。采用单指示剂热稀释法测定EVLWI。观察在不同通气条件下0、1、2和3h EVLWI的变化。结果MVZP组、LVZP组、LVBP组和LVBP+SI组EVLWI在基础时分别为(11.3±2.4)、(10.2±2.4)、(10.3±4.6)和(9.7±2.3)ml/kg,达到ARDS模型(0h)时显著升高[(22.3±5.6)、(20.0±3.8)、(25.7±9.7)和(22.5±6.2)ml/kg,P均<0.05]。在实验观察3h中,MVZP组在2、3h EVLWI[(32.0±12.2)、(36.2±12.4)ml/kg]显著高于0h[(22.3±5.6)ml/kg,P均<0.05]。LVZP组在2、3h EVLWI[(27.8±12.9)、(30.3±13.0)ml/kg]也显著高于0h[(20.0±3.8)ml/kg,P均<0.05];LVBP组1h时EVLWI为(18.5±8.1)ml/kg,与0h[(25.7±9.7)ml/kg]比较差异有统计学意义(P=0.027)。LVBP+SI组在1、2、3h各时点EVLWI分别为(16.8±6.5)、(18.0±7.1)、(15.7±2.7)ml/kg,与0h[(22.5±6.2)ml/kg]比较显著降低(P均<0.05)。与MVZP组比较,1、3h时LVBP组与LVBP+SI组EVLWI显著降低(P均<0.05)。3hLVBP+SI组EVLWI显著低于LVZP组(P<0.05)。结论肺保护与肺开放通气策略可降低EVLWI,增加肺水清除。     

肺复张联合CRRT对老年脓毒症伴呼吸衰竭患者炎性因子及呼吸力学参数的影响

目的探讨肺复张联合持续肾脏替代治疗(CRRT)对老年脓毒症伴呼吸衰竭患者炎性因子及呼吸力学参数的影响。方法选取脓毒症伴呼吸衰竭老年患者60例,随机分为对照组和试验组。所有患者入院后予常规治疗,对照组30例采用肺复张通气治疗,试验组30例在对照组治疗基础上采用CRRT,均连续治疗3 d后,比较两组临床疗效、炎性因子〔白细胞介素(IL)-6、IL-8、肿瘤坏死因子(TNF)-α、C反应蛋白(CRP)〕、呼吸力学参数〔气道阻力(Raw)、气道平台压(Pplat)、潮气量、呼吸系统静态顺应性(Cst)〕。结果试验组总有效率(93.33%)较对照组(73.33%)明显增高,差异有统计学意义(P<0.05)。治疗3 d后,试验组IL-8(120.03±16.27)ng/L、TNF-α(85.33±15.02)ng/L、IL-6(71.11±14.82)ng/L、CRP(14.16±5.07)mg/L水平均明显低于对照组〔(165.30±26.34)ng/L、(146.38±17.0)ng/L、(106.84±16.03)ng/L、(23.11±6.32)mg/L〕,差异有统计学意义(P<0.05)。治疗3 d后,试验组Raw(15.06±2.03)cmH 2O/(L·s)、Pplat(21.15±5.09)cmH 2O水平均明显低于对照组〔(18.02±2.11)cmH 2O/(L·s)、(24.24±6.02)cmH 2O〕,潮气量(9.28±0.96)ml/kg、Cst(30.26±5.23)ml/cmH 2O水平均明显高于对照组〔(8.20±0.85)ml/kg、(26.89±5.11)ml/cmH 2O〕,差异有统计学意义(P<0.05)。结论肺复张联合CRRT可提升老年脓毒症伴呼吸衰竭患者临床疗效,降低炎性因子水平,改善呼吸力学指标。     

吸痰联合肺复张后不同PEEP水平对ARDS机械通气患者呼吸力学的影响

目的探讨吸痰联合肺复张后调整不同的呼气末正压(PEEP)水平对急性呼吸窘迫综合征(ARDS)机械通气患者呼吸力学的影响。方法选择22例ARDS机械通气患者,吸痰后给予肺复张,在原有PEEP水平(P0)基础上调整。于调整PEEP后10、30、60 min,监测患者各压力水平气道峰压(Ppeak)、平台压(Pplat)、肺实时顺应性(Cd)变化。结果与实验前比较,Cd在不同PEEP水平均显著升高(P均<0.05)。随着PEEP水平的不断增加,Cd也随之升高,与调整后其他PEEP水平相比,P0+4 cmH2O和P0+6 cmH2O测得Cd显著高于其他水平(P<0.05)。30 min Cd监测值显著高于10、60 min(P均<0.05)。与其他四组比较,P0+4 cmH2O和P0+6 cmH2O在30～60 min时段Cd下降趋势较小(P<0.05)。随着PEEP水平不断增加,Ppeak、Pplat也随之升高,但不同PEEP水平对Ppeak、Pplat的影响无统计学差异(P>0.05)。结论 ARDS机械通气患者在吸痰联合肺复张后选择在P0基础上增加4～6 cmH2O,有利于维持患者复张后肺顺应性,延缓肺泡去复张时间。     

呼气末压力为零时的静态压力容积曲线在急性呼吸窘迫综合征患者控制性肺膨胀中的应用

目的　评价呼气末压力为零 (ZEEP)时静态压力 容积 (P V)曲线在预测急性呼吸窘迫综合征 (ARDS)患者对控制性肺膨胀 (SI)反应性的作用。方法　 2 0例ARDS患者进行机械通气并测量ZEEP时的静态P V曲线 ,在使用呼气末正压通气 (PEEP) 2h后进行SI。根据 2 0例患者使用SI后改良氧合指数 (PaO2 /FiO2 )进行分组 ,增加≥ 2 0 %为SI反应组 (A组 ) ,<2 0 %为SI无反应组 (B组 )。结果　(1)A组ZEEP时静态P V曲线参数c - 2d≥ 0cmH2 O(1cmH2 O =0 0 98kPa) ,且c≥ 18cmH2 O ,呈向上凹的形态 ;而B组c - 2d <0cmH2 O或c <18cmH2 O ,呈向上凸的形态或一直线。 (2 )使用SI后 ,A组患者可减少肺内分流 (P =0 0 0 6 ) ,而B组不减少肺内分流 (P =0 339)。相同吸气压下的肺容积增加 ,A、B组间比较差异有显著性 [(2 4 1± 111)ml,(2 9± 4 6 )ml,P =0 0 36 ]。结论ARDS患者在ZEEP时静态P V曲线具有不同的形态 ,使用曲线参数的c - 2d及c值可迅速判断静态P V曲线形态 ,对指导预测ARDS患者中SI治疗具有一定的意义。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.