呼吸机3项撤机指标的评价

呼吸机的适时撤离是临床监护的一项重要内容，众多学为寻找精确度高，重复性好，无创或低创的理想撤机指标进行了多方面的研究。本就近年来研究较多的浅快呼吸指数、Ｐ０．１呼吸功这三项指标的临床意义，主要研究结果及发展方向作一综合性评述。     

呼吸机3项撤机指标的评价

呼吸机的适时撤离是临床监护的一项重要内容,众多学者为寻求精确度高、重复性好、无创或低创的理想撤机指标进行了多方面的研究。本文就近年来研究较多的浅快呼吸指数、P_(01)、呼吸功这三项指标的临床意义,主要研究结果及发展方向作一综合性评述。     

呼吸机的撤离

本文对呼吸机撤离困难的原因进行了分析,并论述对其应采取的措施。     

气道闭合压、最大吸气压和呼吸浅快指数对慢阻肺患者撤机的预测价值

目的针对气道闭合压、最大吸气压和呼吸浅快指数对慢阻肺患者撤机的预测价值进行研究。方法随机选择2013年12月-2015年12月期间,医院收治的慢性阻塞性肺疾病(慢阻肺)患者80例,作为本次研究的对象,对患者实施气道闭合压、最大吸气压和呼吸浅快指数等的检测,并根据患者撤机成功与否,比较撤机成功与撤机失败患者的撤机参数。结果在本次研究中慢阻肺患者的进口气管插管机械通气治疗中,患者撤机成功人数为53例,撤机失败人数27例。撤机成功组患者的气道闭合压(P0.1)、最大吸气压(Pi max)和呼吸浅快指数(RSBI)与撤机失败组患者的各项撤机指标进行比较,P0.05,具有统计学意义。慢阻肺患者的撤机指标的预测价值进行分析,气道闭合压(P0.1)的灵敏度最高,为90%,其次是最大吸气压(Pi max)为85%,呼吸浅快指数(RSBI)64%。气道闭合压(P0.1)的特异性最高为76%,其次是呼吸浅快指数(RSBI)的特异性,为57%,最后是最大吸气压(Pi max)为45%。而三种指标的准确率分别为87%、73%、62%,综合分析得出,气道闭合压(P0.1)的预测价值最高,其次是最大吸气压(Pi max)和呼吸浅快指数(RSBI)。结论在慢阻肺患者的撤机中,气道闭合压、最大吸气压可以作为患者的撤机预测指标,呼吸浅快指数也可以在撤机预测中起到一定的作用。     

浅快呼吸指数指导缺血性脑卒中患者撤机的临床观察

目的探讨浅快呼吸指数(RSBI)指导缺血性脑卒中患者撤机的临床价值。方法前瞻性研究,入选在重症医学科进行有创机械通气24 h 40例缺血性脑卒中患者,根据撤机结果将患者分为成功组26例,失败组14例。应用低水平压力支持通气法进行自主呼吸实验(SBT),40例患者均通过了1 h的自主呼吸实验,记录SBT前和SBT1h、SBT1.5h及SBT2h的RSBI,同时记录年龄、性别、APACHEⅡ评分、撤机前30 min的血气分析。结果成功组和失败组年龄、性别、GCS评分、APACHEⅡ评分无明显差异(P0.05),失败组合并冠心病比例较成功组明显升高(P0.05)。以RSBI≤105 bpm/L为标准预测撤机成功的灵敏度和特异度分别为:SBT前93.8%、10.6%,SBT1 h 100%、40.24%、SBT1.5 h 98.2%、38.7%SBT2 h 96.3%、38.2%。结论SBT1 h的RSBI预测缺血性脑卒中患者撤机成功的准确率高。动态观察RSBI对缺血性脑卒中患者成功撤机有一定的预测价值。     

撤机参数在机械通气患者呼吸机撤离中的应用价值

目的　在长时间机械通气患者撤离呼吸机 (简称撤机 )时 ,评价浅快呼吸指数 (RSBI)、气道闭合压 (P0 1)及常规撤机参数的价值。方法　采用前瞻性研究方法 ,对通过自主呼吸试验并满足常规撤机标准的 80例患者 ,检测呼吸运动协调性、痰量、肺部音、咳嗽能力、呼吸频率 (RR)、潮气量(VT)、分钟通气量 (MV)、呼吸系统顺应性 (C)、经皮脉搏容积血氧饱和度 (SpO2 )、动脉血pH值等 10项常规撤机参数及RSBI和P0 1。根据撤机结果分为失败组和成功组。采用单因素 (t检验、χ2 检验 )及多因素Logistic回归进行统计学分析。结果　 16例患者撤机失败。单因素分析显示撤机失败组与成功组之间的年龄、RSBI和P0 1差异有显著性 (P <0 0 5 )。以撤机结果为因变量进行Logistic回归分析显示 :仅RSBI和P0 1是回归模型中差异有显著性的两个参数。两组RSBI分别是 (71± 2 3)次·min-1·L-1和 (5 3± 13)次·min-1·L-1(OR =1 0 3) ,P0 1分别是 (7 4± 2 1)cmH2 O和 (3 6± 1 4 )cmH2 O(OR =6 87)。以RSBI≤ 10 5次·min-1·L-1为标准 ,预测撤机成功的敏感性为 90 % ,特异性为 36 % ,准确性为 78%。以P0 1≤ 4 5cmH2 O为标准 ,预测撤机成功的敏感性为 87% ,特异性为 6 6 % ,准确性为 82 %。 10项常规参数中无一项差异     

自主呼吸试验在撤离呼吸机中的作用

目的 探讨自主呼吸试验(SBT)在机械通气的撤离、拔除气管插管过程中的作用.方法 采用前瞻性随机对照方法,选择67例机械通气超过48 h的患者,当所有患者达到撤离呼吸机状态时将其随机(采用从密封信封中抽取随机号的方法)分为自主呼吸试验组(SBT组,35例)和无自主呼吸试验组(NO-SBT组,32例)两组.SBT组患者顺利通过SBT后随即拔除气管插管,NO-SBT组患者在达到撤离呼吸机条件后,不进行SBT,即拔除气管插管.以拔除气管插管的成功率作为评判的主要指标,成功的标志为拔除气管插管后能维持自主呼吸48 h以上.两组均数的比较采用两个独立样本的t检验,频数的比较采用X~2检验.结果 两组患者在拔除气管插管前的一般状况、呼吸生理和血流动力学等指标比较差异无统计学意义;年龄、性别、气管插管的口径、疾病的严重程度和疾病种类相似,机械通气的时间比较差异尢统计学意义.两组各有3例患者再次气管插管(X~2=0.013,P=0.908).两组患者拔除气管插管后,需无创辅助通气的患者NO-SBT组为5例,SBT组为4例(X~2=0.253,P=0.727).两组患者医院内病死率[N0-SBT组为12.5%(4/32),SBT组为9.7%(3/35),X~2=0.311,P=0.600]差异无统计学意义.结论 SBT可能不是拔除气管插管前的必需过程.     

探讨浅快呼吸指数指导COPD患者撤机的临床价值

目的评价浅快呼吸指数（rapid-shallow-breathing index,RSBI）作为COPD患者撤机的临床价值。方法呼吸重症监护病房的20例机械通气的COPD患者,均通过了1h的自主呼吸实验（spontaneous breathing trial,SBT）。记录两个时期的RS-BI：SBT前、SBT1h。同时记录年龄、性别、APACHEⅡ（acute physiology and chronic health evaluationⅡ）评分、撤机前的动脉血气分析。结果 16例COPD患者成功撤机,4例患者撤机失败。在成功和失败两组间年龄、性别、APACHEⅡ评分无明显差异（P〉0.05）,PaCO2（partial pressure of carbon dioxide in arterial blood）有明显差异（P〈0.05）。以RSBI≤105bpm/L为标准预测撤机成功的灵敏度和特异度分别为：SBT前RSBI93.8%、10%;SBT1h的RSBI93.8%、45.5%。SBT1h的RSBI与PaCO2联合预测撤机成功的灵敏度为89.5%,特异度为78%。结论 SBT1h的RSBI预测COPD患者成功撤机的准确性高于SBT前,其与PaCO2联合评价将提高预测撤机成功的准确性。     

浅快呼吸指数指导AOPP患者撤机的临床研究

目的探讨浅快呼吸指数(light fast breathing index RSBI)作为急性有机磷中毒(acute organophosphate poisoning,AOPP)患者撤机的临床价值。方法重症医学科20例机械通气的AOPP患者均通过了1h的自主呼吸实验(spontaneous breath-ing test SBT),记录了2个时期的RSBI:SBT前、SBT1h,同时记录年龄、性别、APACHEⅡ评分、撤机前30min的动脉血气分析及胆碱酯酶活力(choline esterase vigo CHE)。结果 15例AOPP患者成功撤机,5例患者撤机失败,在成功和失败两组年龄、性别、A-PACHEⅡ评分无明显差异(P>0.05),CHE有明显差异(P<0.05),以RSBI≤105 bpm/L为标准预测撤机成功的灵敏度和特异度分别为:SBT前SBT1 92.8%、10.2%,SBT1h的RSBI预测撤机成功的灵敏度和特异度分别为93.6%、40.5%。SBT1h的RSBI与CHE联合预测撤机成功的灵敏度和特异度分别为90.5%、75%。结论 SBT1h的RSBI预测AOPP撤机成功的准确性高于SBT前,其与CHE联合评价将提高预测撤机成功的准确性。     

膈肌超声联合呼吸力学指标对ICU老年患者撤机预后评价功能

目的 使用超声监测膈肌功能,评价膈肌新指标对老年机械通气患者撤机结果的预测价值.方法 回顾性分析河北省人民医院重症医学科收治的行机械通气治疗时间大于48 h的老年患者44例,满足撤机条件后常规进行自主呼吸试验(SBT)并应用床旁超声监测患者膈肌移动度(DE)、膈肌增厚率(DTF),并结合既往浅快呼吸指数(RSBI)得出...     

Effect of early application of biphasic positive airway pressure on the outcome of extubation in ventilator weaning

Extubation failure is significantly associated with increased morbidity and mortality in mechanically ventilated patients. In respiratory distress after extubation, non-invasive positive pressure ventilation (NIPPV) has been suggested to avoid the complications of invasive mechanical ventilation. The purpose of this study was to evaluate the effect of early application of NIPPV on extubation outcome. We conducted a prospective study in 93 extubated patients with a mean age of 72.7 +/- 14.7 years (range, 24-93). Elective extubation was performed in 56 patients and unplanned extubation occurred in 37 patients. After extubation, patients randomly received either biphasic positive airway pressure (BIPAP) therapy (n = 47) or unassisted oxygen therapy (n = 46). Non-invasive positive pressure ventilation was delivered via face mask in BIPAP group. Of the 93 extubated patients, 73 (78.5%) were successfully extubated, and 20 (21.5%) had to be re-intubated. There were no significant differences in age, sex, pre-extubation blood gas data between re-intubated patients and those who were not re-intubated. While seven of the 46 patients in the unassisted oxygen therapy group required re-intubation, 13 of the 47 BIPAP-treated patients also required re-intubation. This difference was not statistically significant. The postextubation respiratory management, BIPAP or unassisted oxygen therapy, did not correlate with the extubation outcome, but the elective extubation had significantly better outcome than unplanned extubation. Patients with excessive bronchial secretions and intolerance to the equipment are poor candidates for NIPPV. We conclude that early application of BIPAP support did not predict a favourable extubation outcome. Our experience did not support the indiscriminate use of NIPPV to facilitate ventilator weaning.     

Severity scoring in the critically ill: part 1--interpretation and accuracy of outcome prediction scoring systems

This review examines the use of scoring systems to assess ICU performance. APACHE (Acute Physiology and Chronic Health Evaluation), MPM (mortality probability model), and SAPS (simplified acute physiology score) are the three major ICU scoring systems in use today. Central to all three is the use of physiologic data for severity adjustment. Differences in the size, nature, and time horizon of the data set translate into minor differences in accuracy and difficulty of data abstraction. APACHE IV provides ICU and hospital predictions for mortality and length of stay, whereas MPM and SAPS only provide hospital mortality predictions (although new algorithms generated from MPM data elements may predict ICU length of stay adequately). The primary use of scoring systems is for assessing ICU performance, with the ratio of actual-to-predicted outcomes in the study cohort providing performance comparisons to the reference ICUs. The reliability of scoring system predictions depends on the completeness and accuracy of the abstracted data; accordingly, ICUs must implement robust data quality control processes. CIs of the ratios are inversely related to sample size, and care must be taken to avoid overinterpreting changes in outcomes. ICU structural and process issues also can affect scoring system performance measures. Despite good discrimination and calibration, scoring systems are used in only 10% to 15% of US ICUs. Without ICU performance data, there is little hope of improving quality and reducing costs. Current demands for transparency and computerization of documentation are likely to drive future use of ICU scoring systems.     

The role of physical and psychological variables in predicting the outcome of hospitalization in very old adults

The aim of this study was to examine predictors of functional outcome in hospitalized geriatric patients with a focus on psychological variables, as these have been somewhat neglected in this population. A prospective study was conducted in aged-care wards in Melbourne, Australia. Consecutively admitted patients (n = 100, mean age 82 years) completed measures of health status, anxiety, depression, self-efficacy, personality and coping. Two months later data were collected with respect to three outcomes, namely overall functioning, ability to carry out activities of daily living as measured by the Barthel Index (BI), and quality of life (QoL), as measured by the assessment of quality of life (AQoL) instrument. Syndromal depression was highly prevalent (28%) and syndromal anxiety was less common (5% prevalence), but neither was predictive of functional outcome. The strongest predictor of outcome was physical health status on admission to hospital. The results suggest that in physically unwell, very old populations, physical health factors may be stronger predictors of functioning than psychological variables. The findings also highlight some difficulties in the use of psychological measures in old-old populations, and the need for more research that recognizes the oldest old as a distinct group.     

Comparison of clinical and treadmill variables for the prediction of outcome after myocardial infarction

To assess the relative prognostic merits of 15 clinical and 10 predischarge exercise test variables, 226 patients who had sustained an acute myocardial infarction were studied. A submaximal treadmill test was performed on 205 patients to a mean work load of 5.7 +/- 2.9 METS. Testing was performed an average of 11.7 (range 6 to 33) days after myocardial infarction. During the first year of observation, major cardiac events were noted in 33 patients (16%), unstable angina in 7 (3.4%), recurrent myocardial infarction in 14 (6.8%) and death in 12 patients (5.9%). Cardiac mortality correlated with mean peak serum creatine kinase (CK) (p less than 0.05), history of previous myocardial infarction (p less than 0.01) and ST segment depression at rest (p less than 0.01). The only exercise variable that correlated with cardiac mortality was poor exercise endurance (p less than 0.05). Multivariate risk stratification of clinical and treadmill variables from these 205 patients using linear discriminant analysis produced a function that correctly classified 95% of those who were event-free and 80% of those who died. The first four discriminant variables that contributed independent information for the prediction of cardiac mortality were: 1) ST segment depression at rest; 2) CK greater than 1,280 IU/liter; 3) exercise duration less than 3 minutes; and 4) a history of previous myocardial infarction. ST segment depression on the predischarge treadmill test did not predict any event, nor did it improve the predictive accuracy of the clinical variables. It is concluded that a history of previous myocardial infarction and ST segment depression on the rest electrocardiogram indicate a poor prognosis after acute myocardial infarction. Poor endurance is the only exercise variable that suggests a future cardiac event. Prognosis after acute myocardial infarction is more accurately predicted by these clinical data than by variables derived from the predischarge treadmill test.     

Effects of weaning and rearing environment on intestinal gene expression of IGF-I,IGFBP (1-6), and the IGF receptor and on specific binding of IGF-I to mucosal membranes in the pig

The objective of this study was to investigate changes in gene expression of intestinal IGF-I, IGFBPs, and IGF-I receptor in pigs in response to weaning and different rearing environment. Pigs were weaned early at 12 days of age and either remained on-site in a separate facility (CON) or were moved to a segregated site with reduced infection pressure (segregated early weaning; SEW). Small intestinal samples were collected from a total of 15 pigs killed at 11 (pre-weaning), 15 (3 days post-weaning), and 34 days of age. Intestinal IGF-I mRNA levels were higher (P < 0.01) in SEW than in CON pigs at 3 days post-weaning, but not at 34 days of age. Weaning reduced (P < 0.05) both IGF-IR mRNA levels and specific binding of IGF-1 in the jejunum in both groups at day 34, but only in SEW pigs (P < 0.05) at day 3 post-weaning. Weaning resulted in a major reduction (P < 0.05) in intestinal IGFBP-2 mRNA, with no difference between SEW and CON. Intestinal IGFBP-3 mRNA levels were unaffected by weaning or post-weaning environment. Weaning did not affect intestinal IGFBP-4 mRNA levels, except for an increase (P < 0.05) in CON pigs compared to pre-weaning, and to SEW pigs at 3 days post-weaning. The abundance of IGFBP-5 mRNA in the gut was highly variable with no apparent treatment effect. Intestinal IGFBP-6 mRNA levels were reduced (P < 0.05) after weaning, with lower (P < 0.05) levels in SEW pigs than in CON pigs at 34 days of age. This study documents the changes in IGF-1, IGF-IR, and IGFBP mRNA abundance, and in IGF-1 binding during post-weaning adaptation of the intestine in early-weaned pigs. In addition, the relative differences observed in intestinal expression of IGF-1, IGF-IR, and in IGF-1 binding between the post-weaning environments are consistent with previous observations in a companion study indicating that segregated early weaning enhances post-weaning intestinal maturation in pigs.     

Evaluation of diagnostic findings and scoring systems in outcome prediction in acute pancreatitis

AIM: To determine factors related to disease severity, mortality and morbidity in acute pancreatitis. METHODS: One hundred and ninety-nine consecutive patients were admitted with the diagnosis of acute pancreatitis (AP) in a 5-year period (1998-2002). In a prospective design, demographic data, etiology, mean hospital admission time, clinical, radiological, biochemical findings, treatment modalities, mortality and morbidity were recorded. Endocrine insuffi ciency was investigated with oral glucose tolerance test. The relations between these parameters, scoring systems (Ranson, Imrie and APACHE Ⅱ) and patients' outcome were determined by using invariable tests and the receiver operating characteristics curve. RESULTS: One hundred patients were men and 99 were women; the mean age was 55 years. Biliary pancreatitis was the most common form, followed by idiopathic pancreatitis (53/ and 26/, respectively). Sixty-three patients had severe pancreatitis and 136 had mild disease. Respiratory rate > 20/min, pulse rate > 90/min, increased C-reactive protein (CRP), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) levels, organ necrosis > 30/ on computed tomography (CT) and leukocytosis were associated with severe disease. The rate of glucose intolerance, morbidity and mortality were 24.1/, 24.8/ and 13.6/, respectively. CRP > 142 mg/L, BUN > 22 mg/dL, LDH > 667 U/L, base excess > -5, CT severity index > 3 and APACHE score > 8 were related to morbidity and mortality. CONCLUSION: APACHE Ⅱ score, LDH, base excess and CT severity index have prognostic value and CRP is a reliable marker for predicting both mortality and morbidity.     

Contrast-enhanced harmonic endoscopic ultrasonography for predicting the efficacy of first-line gemcitabine and nab-paclitaxel chemotherapy in pancreatic cancer

Background and aimsThe purpose of this study was to assess prognosis with different intratumoral vascularity on contrast-enhanced endoscopic harmonic ultrasonography (CH-EUS) in pancreatic cancer patients receiving chemotherapy.MethodsPatients with unresectable pancreatic cancer who underwent CH-EUS before first-line gemcitabine and nab-paclitaxel (GEM and nab-PTX) therapy were classified into four groups according to vascularity on the early and late phases of contrast enhancement: “Group A″, poor on both phases; “Group B″, rich and poor on the early and late phases, respectively; “Group C″, poor and rich on the early and late phases; “Group D″, rich on both phases. Subgroups were compared in terms of progression-free survival (PFS) and overall survival (OS). We also assessed whether the results with CH-EUS correlate with those of contrast-enhanced computed tomography (CE-CT).ResultsOn CH-EUS, 57, 64, 0, and 24 patients were classified into Groups A, B, C, and D, respectively. The median PFS of patients in groups A, B, and D was 3.9, 7.6, and 10.8 months, respectively, and the median OS were 9.5, 13.1, and 18.6 months, respectively. Both PFS and OS were longest in Group D (p < 0.001 and p < 0.001, respectively). The results of CE-CT were consistent with those of CH-EUS, and there was a correlation between CE-CT and CH-EUS.ConclusionsEvaluation of intratumoral vascularity by CH-EUS may be useful for predicting the efficacy of chemotherapy in patients with pancreatic cancer. A better response to GEM and nab-PTX can be expected in patients showing rich vascularity at both the early and late phases.     

Relative power of clinical, exercise test, and angiographic variables in predicting clinical outcome after myocardial infarction: the Newham and Tower Hamlets study

The interrelations of clinical, exercise test, and angiographic variables and their relative values in predicting specific clinical outcomes after myocardial infarction have not been fully established. Of 302 consecutive stable survivors of infarction, 262 performed a predischarge submaximal exercise test. In the first year after infarction patients with a "positive" exercise test were 13 times more likely to die, 2.8 times more likely to have an ischaemic event, and 2.3 times more likely to develop left ventricular failure than patients with negative tests. Patients with positive exercise tests underwent cardiac catheterization. Features of the history, 12 lead electrocardiogram, in-hospital clinical course, exercise test, and left ventricular and coronary angiograms that predicted these clinical end points were identified by univariate analysis. Then multivariable analysis was used to assess the relative powers of all variables in predicting end points. Certain features of the exercise test remained independent predictors of future ischaemic events and the development of overt left ventricular failure, but clinical and angiographic variables were more powerful predictors of mortality. Because the exercise test is also used to select patients for angiography, however, the results of this study strongly support the use of early submaximal exercise testing after infarction.