波浪床对压力性溃疡患者MMP-2，9含量的影响及其疗效观察

目的：观察波浪床对压力性溃疡（PU）患者伤口渗液及组织中基质金属蛋白酶-2，9（MMP-2，9）表达的影响，同时探讨MMP-2，9在PU不同时期的表达及其与PU愈合间的关系。方法：将24例PU患者分为治疗组（8例）及对照组（16例），其中治疗组患者于波浪床上进行翻身治疗，而对照组患者则在普通标准床上进行翻身治疗。采用Push Tool工具评定2组患者PU愈合情况，选用明胶酶谱法及RT-PCR法检测PU伤口渗液中MMP-2，9蛋白含量及组织中MMP-2mRNA表达水平。结果：2组患者Push Tool评分结果随治疗进展呈逐渐下渐趋势，治疗组第21天时Push Tool评分较对照组显著降低，进一步分析后发现，患者PU伤口渗液中MMP-2，9比活性与Push Tool评分呈高度正相关性；2组患者MMP-2，9均呈下降趋势，治疗组患者MMP-2，9水平在第7及21天时均较对照组显著降低，差异具有统计学意义（P〈0．05）。结论;MMP-2，9可作为评定PU愈合状况的生化标记物之一，同时本研究结果也进一步证实了波浪床综合疗法对PU患者具有显著疗效。     

封闭式负压引流技术在人压力性溃疡创面治疗中的临床应用

目的:探讨封闭式负压引流技术治疗人压力性溃疡的疗效。方法:将30例Ⅲ-Ⅳ期压力性溃疡患者随机分成实验组和对照组各15例,对照组创面应用常规敷料换药治疗。采用压力性溃疡PUSH Tool 3.0评分分别于治疗前,治疗后7 d、14 d评估创面愈合情况,并观察创缘全层皮肤组织愈合过程中的镜下HE染色表现。结果:随着治疗时间延长,实验组创面渗液减少,创缘新生上皮及肉芽组织逐渐增多,治疗第14 d,实验组创面Push Tool评分明显低于对照组(7.40±0.27 VS 12.53±0.22,P0.01)。结论:封闭式负压引流疗法较普通换药更能够减少创面渗液,有利于肉芽组织生长,促进创面愈合。     

生肌液复合封闭负压引流对创面肉芽组织增殖的作用

背景：传统生肌中药促进创面愈合疗效独特，封闭负压引流技术是新兴的创面治疗方法。目的：从组织学角度观察生肌液和封闭负压引流技术相结合对实验动物创面愈合的影响。设计、时间及地点：随机对照动物实验，于2006—05／10在河南省正骨研究院生物工程实验室完成。材料：100只SD大鼠随机分为模型组、麻油纱布组、生肌液纱布组、封闭负压引流组、生肌液复合封闭负压引流组，每组20只。生肌液和麻油煎剂均由本院制剂室规范制备。方法：在每只大鼠背部制作2个皮肤切除伤创面模型。模型组等待创面自然愈合，麻油纱布组以两层麻油纱布敷于创面上，生肌液纱布组以两层生肌液纱布敷于创面上；封闭负压引流组给予创面封闭负压引流治疗。生肌液外用结合封闭负压引流组：给予创面封闭负压引流治疗，负压吸引间歇期从注药管注入生肌液。每组20只动物随机分4批各10个创面，第1，2，3个批次分别用于3，6，9天取材观察创面的愈合率和创面组织形态学变化。第4个批次观察创面愈合时间。主要观察指标：①创面的愈合率。②创面愈合时间。③创面组织形态学变化。结果：①各组创面第3天愈合率比较差异无显著性意义（P〉0．05）。3d后封闭负压引流组及复合组愈合速度明显加快。第9天愈合率由高到低依次为复合组、封闭负压引流组、生肌液纱布组、麻油纱布组和模型组，组间比较差异有显著性意义（P〈0．05）。各组愈合时间由快到慢排序同上。②第3天封闭负压引流组毛细血管数略高于复合组（P〉0．05）；第6天复合组毛细血管数高于封闭负压引流组（P〈0．05）：第3天各组成纤维细胞数均维持在较低水平，组间比较差异无显著性意义（P〉0．05）第6天复合组成纤维细胞数高于封闭负压引流组（P〈0．05）。结论：生肌液复合封闭负压引流技术可以更好地促进创面愈合。封闭负压引流技术在创面愈合的早期能明显促进组织细胞增殖；生肌液在中后期可以延续组织细胞的增殖趋势。     

封闭负压引流技术对创周组织水肿及血管通透性的影响

目的 创面封闭负压引流技术促进创面愈合的机制尚未清楚，探讨封闭负压引流对创周组织水肿及血管通透性的影响。方法 以兔耳背全层皮肤缺损的急性创面为模型，右耳用创面多孔闭合敷料，并给予负压引流，为治疗组；左耳创面不作封闭负压引流，其余处理同治疗组，为对照组。在治疗后第2，4，6，8天分别利用于湿法检测对照组和治疗组创周组织的含水量，同时用伊文氏蓝渗出法检测创周组织的血管通透性。结果 封闭负压引流组创周组织含水量在2，4，6，8d均低于对照组(P&;lt;0．05)；伊文氏蓝含量在第2天两组差异无显著性意义(P&;gt;0．05)，但在4，6，8d明显低于对照组(P&;lt;0．01)。结论 封闭负压引流治疗可以有效的减轻创周水肿、降低血管通透性。     

封闭负压引流装置在Ⅳ度褥疮患者中的应用及护理

目的观察封闭负压引流装置治疗Ⅳ度褥疮的临床效果。方法20例Ⅳ度褥疮患者创面按外科常规清创后。将封闭负压引流装置覆盖褥疮创面持续负压吸引。结果18例痊愈,创面愈合率为90．0％;2例好转但未完全愈合,另采取他法换药;20例感染创面致病菌全部转阴,感染控制率为lOO％。结论封闭负压引流技术治疗Ⅳ度溃疡期褥疮,具有治疗时间短、褥疮愈合快、操作方法简单、可接受性强等优点。     

负压封闭引流治疗严重软组织损伤的疗效观察与护理

目的 探讨负压封闭引流治疗严重软组织损伤的疗效及护理。方法 100例严重软组织损伤患者随机分成负压封闭引流组50例和常规换药组50例。结果 负压封闭引流组中有8例患者获得Ⅱ期缝合愈合,而常规换药组中无1例患者获得Ⅱ期愈合,负压封闭引流组的愈合率明显高于常规换药组(P<0.01),负压封闭引流组患者创面平均清洁时间比常规换药组明显快(P<0.01)。结论 负压封闭引流治疗严重软组织损伤创面愈合明显优于常规换药,加强负压封闭引流的管理和创面护理才能保证有效的引流和缩短疗程。     

负压封闭引流技术治疗骨筋膜室综合征

目的探讨负压封闭引流技术在骨筋膜室综合征治疗中的临床应用。方法 2008年12月~2011年8月使用负压封闭引流装置覆盖骨筋膜室综合征切开减张术后创面。结果术后5~10 d移除引流敷料,见切口内肉芽组织新鲜,无明显感染。11例减张伤口予直接缝合,14例伤口行植皮术。随访时间3~18个月,创面愈合良好,无功能障碍,外形满意。结论负压封闭引流可有效处理骨筋膜室综合征减张术后伤口。     

改良负压封闭引流联合祛腐生肌中药灌洗治疗Ⅳ期及以上压疮的效果观察

目的探讨自行改良的负压封闭引流联合祛腐生肌中药灌洗治疗Ⅳ期及以上压疮的效果。方法将90例Ⅳ期及以上压疮患者随机分为对照组和观察1组、观察2组各30例。对照组常规予创面清创,使用藻酸盐或抗菌敷料填塞、换药;观察1组创面清创后行改良的负压封闭引流治疗:用一次性无菌高弹力海绵加普通一次性16号胃管代替内置引流管的负压封闭引流敷料覆盖充填创面,1次负压封闭引流治疗维持有效引流5~7 d后拔除或更换;观察2组创面清创后按观察1组的负压封闭引流联合祛腐生肌中药灌洗治疗。比较3组肉芽组织生长时间、创面愈合时间、治疗42 d时疗效。结果 3组患者治疗42 d时疗效比较差异有统计学意义(P0.05);观察2组优于观察1组(P0.05)和对照组(P0.05);观察1组优于对照组(P0.05)。3组患者压疮肉芽组织生长时间、创面愈合时间比较,差异均有统计学意义(P0.05),观察2组均早于观察1组(P0.05)和对照组(P0.05);观察1组早于对照组(P0.05)。结论使用自行改良的负压封闭引流装置联合祛腐生肌中药灌洗治疗Ⅳ期及以上压疮,疗效更好,压疮创面新鲜肉芽组织生长的时间更快,有效缩短了伤口愈合时间。     

多功能波浪床联合封闭式负压引流治疗严重压疮的护理

目的探讨多功能波浪床联合封闭式负压引流治疗严重压疮的护理效果。方法将Ⅳ期以上压疮患者随机分为两组,研究组35例应用多功能波浪床联合封闭式负压引流方法治疗。对照组36例采用常规治疗。观察两组患者压疮治愈率、有效率。结果研究组压疮治愈率25．7％,对照组压疮治愈率5．6％;研究组总有效率60％,对照组总有效率30．5％,两组比较差异有统计学意义（χ2分别为4．08,6．55;P〈0．05）。结论多功能波浪床联合封闭式负压引流方法可提高Ⅳ期以上压疮的治疗效果。     

应用负压封闭引流的物理学技术修复会阴部软组织损伤

目的：探讨应用负压封闭引流的物理学方法修复损伤创面会阴部软组织缺损的效果。方法：负压封闭引流组为第三军医大学大坪医院1998-08／2003-07住院患者32例，对照组为1996-01／1998-12创伤中心收治的采用常规换药或引流的同类创伤患者17例。清创后将Vacuseal材料覆盖在相应大小的创面上或创腔内，维持负压在50～60kPa，7～9d后二期缝合、植皮或皮瓣转移。治疗后进行形态学和治疗效果观察。结果：按实际处理分析，32例患者中，5例未能完成治疗，27例患者完成整个负压封闭引流治疗过程。①患者负压封闭引流治疗后形态学观察：创面缩小约20％，死腔完全消灭，创面肉芽组织平坦、新鲜，毛细血管丰富，创面有渗血，肉芽无水肿，创面无渗出。②27例患者创面经二期处理后全部治愈；创面或创腔直接通过负压封闭引流治愈4例，采用局部转移皮瓣关闭7例，植皮关闭13个，二期缝合3例。③二期缝合、植皮、皮瓣转移时间，住院时间负压封闭引流组均显著小于对照组[(8.5&;#177;2.0)，(15．1&;#177;5．8)d；(22．4&;#177;7.5)，(32.1&;#177;12．6)d，P&;lt;0．01]。负压封闭引流组创面缩小程度大于对照组[(5．2&;#177;2.3)，(2.0&;#177;0.3)cm，P&;lt;0．01]。结论：应用药理治疗技术的负压封闭引流方法，能防止创面污染，充分引流可剌激创面肉芽组织快速良好生长，缩短治愈时间。对创伤后的急慢性软组织缺损患者的治疗简单，并易于接受。     

Systolic pressure variation and pulse pressure variation during modifications of arterial pressure

OBJECTIVE: This study was performed to investigate the effect of vasopressor therapy on systolic pressure variation (SPV) and pulse pressure variation (PPV) compared to experimentally measured left ventricular stroke volume variation (SVV). DESIGN AND SETTING: Prospective study in a university laboratory. SUBJECTS: Twelve anesthetized and mechanically ventilated pigs. INTERVENTIONS: Increase in mean arterial pressure (by 100%) using phenylephrine and decrease (by 38%) using adenosine. MEASUREMENTS AND RESULTS: SPV and PPV were calculated and compared to SVV derived from aortic blood flow measurements. SPV was significantly affected by changes in arterial pressure [4.6% (1.5) vs. 6.3% (2.1), p[Symbol: see text]<[Symbol: see text]0.05, increased vs. decreased arterial pressure], whereas PPV did not change during modifications of arterial pressure. During baseline conditions and decreased afterload, correlation with SVV was good both for SPV (r[Symbol: see text]=[Symbol: see text]0.892 and r[Symbol: see text]=[Symbol: see text]0.859, respectively) and for PPV (r[Symbol: see text]=[Symbol: see text]0.870 and r[Symbol: see text]=[Symbol: see text]0.871, respectively) (all p[Symbol: see text]<[Symbol: see text]0.001). Correlation with SVV was only moderate during increased arterial pressure (r[Symbol: see text]=[Symbol: see text]0.683 for SPV and r[Symbol: see text]=[Symbol: see text]0.732 for PPV, p[Symbol: see text]<[Symbol: see text]0.05). CONCLUSION: For guiding fluid therapy in patients under vasopressor support, PPV seems superior to SPV.     

Effect of positive end-expiratory pressure on intra-abdominal pressure

Massive elevation of intra-abdominal pressure (IAP) causes renal, cardiovascular, and respiratory dysfunction. Positive end-expiratory pressure (PEEP) markedly increases the detrimental effect of IAP on the cardiovascular system. The purpose of this study was to determine the effect of PEEP on IAP. In 15 patients requiring mechanical ventilation, IAP was measured, after 15-minute equilibration intervals, at PEEP levels of 0, 5, 10, and 15 cm H2O. Parametric analysis with multiple paired t tests and nonparametric analysis with Spearman's rho and Kendall's tau tests were used to determine correlation between PEEP and IAP. All patients were male. The mean age was 39 years (range, 18-77). Ten patients had just had laparotomy. No correlation was found between PEEP and IAP. We conclude that PEEP of 15 cm H2O or less has no effect on IAP, and we discuss the clinical implications.     

Intracranial pressure. Intracranial pressure monitoring

Based on the data on the current literature, the authors present the basic physiological and pathophysiological aspects of measurement of intracranial pressure and discuss indications for its monitoring and clinical value.     

Plasma osmotic pressure and oncotic pressure

Water distribution in the body fluid is controlled by osmotic pressure and oncotic pressure of plasma. Lower plasma osmotic pressure induces intracellular edema, while lower plasma oncotic pressure induces extracellular edema. The increase in osmo-active substance in plasma induces increase in plasma volume (or extracellular fluid), and then results in extracellular edema.     

Quantification of pressure relief using interface pressure and tissue perfusion in alternating pressure air mattresses

OBJECTIVE: To examine whether the interface pressure (IP) relief provided by alternating pressure air mattresses (APAMs) is matched with maintenance of tissue perfusion over the points of contact by measuring transcutaneous oxygen and carbon dioxide (tcPO2, tcPCO2). DESIGN: Comparative analysis of 2 APAMs with a 2-parameter continuous time-based method for quantifying pressure relief (PR) and transcutaneous gas measurement for assessing tissue perfusion. SETTING: Rehabilitation research facility in a university hospital. PARTICIPANTS: Eleven able-bodied adult postgraduate student volunteers. MAIN OUTCOME MEASURES: Two full-replacement APAM systems were used. For each mattress the mean maximum and minimum interface pressures; mean peak air pressures in the mattresses; interface pressure durations below 30, 20, and 10 mmHg over a 60-minute period; mean maximum tcPCO2 and minimum tcPO2; and mean area under the tcPO2 and tcPCO2 curves were measured for each subject. RESULTS: IP on the sacrum was held below thresholds of 30, 20, and 10 mmHg longer on a 2-cell, low pressure system than on a 3-cell, high pressure system (p < .001). Integrated over time, tcPO2 levels also indicated that the 2-cell system retained oxygen levels closer to the unloaded baseline than did the 3-cell system (p < .01). tcPCO2 levels did not rise significantly (p > 0.1) compared with the baseline measurement in both mattresses. CONCLUSIONS: PR was sensitive to the design of the APAM, especially its inflation pressure, cycle time, and inflation sequence. If future trials demonstrate that PR values and transcutaneous blood gas measurements correlate significantly with the clinical incidence of pressure sore formation, then this technique may prove useful in assessing the effectiveness of alternating pressure support surfaces.     

The effects of NG-nitro-L-arginine methyl ester on systolic pressure, diastolic pressure and pulse pressure according to the initial level of blood pressure

The objective of this study was to re-examine whether the effect of the nitric oxide synthesis inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), on blood pressure depends on peripheral vascular tone. The effects of L-NAME (10 mg/kg, i.v.) on diastolic blood pressure (DBP), systolic blood pressure (SBP), pulse pressure (PP) and heart rate (HR) were studied in pithed rats. Sal-pithed rats received 0.9% NaCl, 10 microl/kg/min. Vascular tone was step-wise increased with 3, 10 and 30 microg/kg/min intravenous phenylephrine infusion (LPhe-pithed, MPhe-pithed and HPhe-pithed rats respectively). L-NAME elicited vasopressor responses in all the animals studied. L-NAME increases in SBP and DBP in Sal-pithed rats were significantly smaller than the ones obtained in phenylephrine infused rats. The increases in DBP elicited by L-NAME were greater in LPhe-pithed rats compared with those of MPhe-pithed and HPhe-pithed rats (i.e. the step-wise rises in DBP obtained with phenylephrine were inversely related to the increases in DBP produced by L-NAME); however, the increases in SBP were similar between these experimental groups. The PP increased during L-NAME-induced pressor responses in phenylephrine-infused rats. l-NAME increases in PP showed the following order: Sal-pithed < LPhe-pithed < MPhe-pithed < or = HPhe-pithed rats. HR was not modified by L-NAME. In conclusion, the vasopressor responses produced by L-NAME in pithed rats are influenced by the pre-existing vasomotor tone in complex form. We did not find a simple positive correlation between the vascular tone or level of arterial pressure, and the magnitude of the diastolic and systolic pressor responses elicited by L-NAME. Interestingly, the increase in PP induced by l-NAME was greater in accordance with the increasing value of baseline arterial pressure. NO synthesis inhibition in the arterial endothelium may possibly explain the increase in PP caused by L-NAME, as resulting from the reduction in proximal conduit artery compliance.     

Effects of relaxation of inspiratory muscleson ventilator pressure during pressure support

OBJECTIVE: During pressure support ventilation (PS), an abrupt increase in ventilator pressure above the pre-set level is considered to signify expiratory muscle activity. However, relaxation of inspiratory muscles may also cause the same phenomenon, and this hypothesis has not been explored. The aim of this study is to examine the cause of this increase in ventilator pressure, during PS, in critically ill patients. DESIGN: Retrospective study. SETTING: In a university intensive care unit. METHODS: Fifteen patients instrumented with esophageal and gastric balloons, and in whom airway pressure (P (aw)) during PS exhibited an acute increase above the pre-set level towards the end of mechanical inspiration were retrospectively analyzed. For each breath, the time of the rapid increase in P (aw) was identified (t (Paw)) and, using the transdiaphragmatic (P (di)) and gastric (P (ga)) pressure waveforms, related to: (1) the end of neural inspiration (peak P (di)) and (2) the time at which P (ga) started to increase rapidly after the end of neural inspiration indicating expiratory muscle recruitment. RESULTS: The t (Paw) was observed 32+/-34ms after the end of neural inspiration, well before (323+/-182ms) expiratory muscle recruitment (identified in eight patients). There was a significant linear relationship between the rate of rise of P (aw) after t (Paw) and the rates of decline of P (di) and inspiratory flow. CONCLUSION: We conclude that, during PS ventilation, the relaxation of inspiratory muscles accounts for the acute increase in P (aw) above the pre-set level, in addition to the contribution made by the occurrence of expiratory muscle activity.     

Influence of tissue pressure on central venous pressure/peripheral venous pressure correlation: An experimental report

BACKGROUND: Peripheral venous pressure (PVP) has been shown to correlate with central venous pressure (CVP) in a number of reports. Few studies, however, have explored the relationship between tissue pressure (TP) and PVP/CVP correlation.METHODS: PVP and CVP were simultaneously recorded in a bench-top model of the venous circulation of the upper limb and in a single human volunteer after undergoing graded manipulation of tissue pressure surrounding the intervening venous conduit. Measures of correlation were determined below and above a point wherein absolute CVP exceeded TP.RESULTS: Greater correlation was observed between PVP and CVP when CVP exceeded TP in both models. Linear regression slope was 0.975 (95% CI: 0.959-0.990); r² 0.998 above tissue pressure 10 cmH₂O vs. 0.393 (95% CI: 0.360-0.426); and r² 0.972 below 10 cmH₂O at a flow rate of 2000 mL/h in the in vitro model. Linear regression slope was 0.839 (95% CI: 0.754-0.925); r² 0.933 above tissue pressure 10 mmHg vs. slope 0.238 (95% CI: -0.052-0.528); and r²0.276 in the en vivo model.CONCLUSION: PVP more accurately reflects CVP when absolute CVP values exceed tissue pressure.     

Pulmonary artery pressure versus pulmonary capillary wedge pressure and central venous pressure in shock

Evidence is presented from 43 dogs and 30 patients that under conditions of severe hemorrhagic, traumatic or septic shock, there may be partial obstruction of the pulmonary microcirculation due to disseminated intravascular coagulation (DIC) particularly in the pulmonary venules. This may cause the left atrial pressure to fall and the pulmonary artery pressure to rise, in some cases drastically. Pulmonary edema may result. This dangerous rise in pulmonary artery pressure is not reflected by the wedged pulmonary artery catheter which will monitor only the status of the left heart. Central venous pressure (CVP) may remain within normal limits even after pulmonary artery pressure has risen to dangerous levels with the development of pulmonary edema. It is only with right ventricle failure against the high pulmonary pressure that CVP rises. It is concluded that pulmonary artery pressure measurements are very important in monitoring intravenous fluid administration in severe shock. Wedged pulmonary artery pressures monitor the left heart but may be misleading if taken alone. Central venous pressure gives a delayed response to fluid overload.