Acute effects of combined high-frequency oscillation and tracheal gas insufflation in severe acute respiratory distress syndrome

OBJECTIVE: In acute respiratory distress syndrome (ARDS), high-frequency oscillation (HFO) improves oxygenation relative to conventional mechanical ventilation (CMV). Alveolar ventilation is improved by adding tracheal gas insufflation (TGI) to CMV. We hypothesized that combined HFO and TGI (HFO-TGI) might result in improved gas exchange relative to both standard HFO and CMV according to the ARDS Network protocol. DESIGN: Prospective, randomized, crossover study. SETTING: A 30-bed university intensive care unit. PATIENTS: A total of 14 patients with early (<72 hrs in duration), severe (PaO2/FiO2 of <150 mm Hg and prerecruitment oxygenation index of 22.8 +/- 1.9 [mean +/- SEM]), primary ARDS. INTERVENTIONS: Patients were ventilated with HFO without (60 mins) and combined with TGI (6.1 +/- 0.1 L/min, 60 mins) in random order. HFO sessions were repeated in inverse order within 24 hrs. HFO sessions were preceded and followed by ARDS Network CMV. Four recruitment maneuvers were performed during the study period. During HFO sessions, mean airway pressure was set at 1 cm H2O above the point of maximal curvature of the respiratory system expiratory pressure-volume curve. MEASUREMENTS AND MAIN RESULTS: Gas exchange and hemodynamics were determined before, during, and after HFO sessions. HFO-TGI improved PaO2/FiO2 relative to HFO and CMV (174.5 +/- 10.4 vs. 136.0 +/- 10.0 and 105.0 +/- 3.7 mm Hg, respectively, p < .05 for both) and oxygenation index relative to HFO (17.1 +/- 1.3 vs. 22.3 +/- 1.7, respectively p < .05). PaO2/FiO2 returned to baseline within 3 hrs after HFO. During HFO-TGI, shunt fraction and mixed venous oxygen saturation improved relative to CMV (0.36 +/- 0.01 vs. 0.45 +/- 0.01 and 77.8% +/- 1.2% vs. 71.8% +/- 1.3%, respectively, p < .05 for both). PaCO2 and hemodynamics were unaffected by HFO sessions. Respiratory mechanics remained unchanged throughout the study period. CONCLUSIONS: In early onset, primary, severe ARDS, short-term HFO-TGI improves oxygenation relative to standard HFO and ARDS Network CMV.     

Inhaled nitric oxide in acute respiratory distress syndrome with and without septic shock requiring norepinephrine administration: a dose–response study

BACKGROUND: The aim of this prospective study was to assess whether the presence of septic shock could influence the dose response to inhaled nitric oxide (NO) in NO-responding patients with adult respiratory distress syndrome (ARDS). RESULTS: Eight patients with ARDS and without septic shock (PaO2 = 95 +/- 16 mmHg, PEEP = 0, FiO2 = 1.0), and eight patients with ARDS and septic shock (PaO2 = 88 +/- 11 mmHg, PEEP = 0, FiO2 = 1.0) receiving exclusively norepinephrine were studied. All responded to 15 ppm inhaled NO with an increase in PaO2 of at least 40 mmHg, at FiO2 1.0 and PEEP 10 cmH2O. Inspiratory intratracheal NO concentrations were recorded continuously using a fast response time chemiluminescence apparatus. Seven inspiratory NO concentrations were randomly administered: 0.15, 0.45, 1.5, 4.5, 15, 45 and 150 ppm. In both groups, NO induced a dose-dependent decrease in mean pulmonary artery pressure (MPAP), pulmonary vascular resistance index (PVRI), and venous admixture (QVA/QT), and a dose-dependent increase in PaO2/FiO2 (P 相似文献   

Beneficial effect of a prone position for patients with hypoxemia after transthoracic esophagectomy

OBJECTIVE: Although the prone position has been reported to improve arterial oxygenation in patients with acute respiratory distress syndrome, there have been no reports on its efficacy in patients with hypoxemia after transthoracic esophagectomy with three-field lymphadenectomy. This study was undertaken to assess the efficacy of the prone position on hypoxemia after three-field lymphadenectomy for thoracic esophageal carcinoma. DESIGN: Prospective randomized clinical study. SETTING: General intensive care unit at a university hospital. INTERVENTIONS AND MEASUREMENTS: Sixteen patients who underwent three-field lymphadenectomy and showed hypoxemia (PaO2/FiO2 ratios of <200 under positive end-expiratory pressure of >5 cm H2O) on the fifth postoperative day were randomly assigned to prone (eight patients) and nonprone (eight patients) groups. Prone position for 6 hrs was carried out for four consecutive days. The PaO2/FiO2 ratio, the duration of ventilatory support, and length of stay, were measured. RESULTS: Oxygenation: The PaO2/FiO2 ratio markedly increased by 32% +/- 22% in seven of eight patients (p <.05) when the patients were moved from the supine to the prone position. The PaO2/FiO2 ratio after the fourth prone position (238 +/- 55, p <.05) was significantly higher than that before the first trial of prone position (166 +/- 25) in these seven patients. Duration of ventilatory support and intensive care unit length of stay: Both the ventilation period (11.6 +/- 2.2 vs. 14.0 +/- 1.6 days, p =.0029) and the length of stay in the intensive care unit (12.8 +/- 4.4 vs. 17.2 +/- 3.4 days, p =.0032) were significantly shorter in the prone group compared with the nonprone group. The PaO2/FiO2 ratio at the time of cessation of prone positioning was significantly higher than the corresponding value in the nonprone group. CONCLUSION: In hypoxemic patients after three-field lymphadenectomy, the prone position improved arterial oxygenation without any deleterious effects. The beneficial effect of the prone position is possibly attributable to opening of the bronchi obstructed by secretions.     

Continuous flow peritoneal dialysis: assessment of fluid and solute removal in a high-flow model of "fresh dialysate single pass".

BACKGROUND: Growing concern over the limited capacity of the peritoneal dialysis (PD) system has revived interest in continuous flow peritoneal dialysis (CFPD), a modality in which continuous circulation of PD fluid is maintained at a high flow rate using two separate catheters or one dual-lumen catheter.The CFPD regimen contrasts the "inflow/outflow" regimen, which requires specific times devoted to filling and draining the peritoneum via a single-lumen catheter. Historical data established CFPD capabilities in providing higher solute clearance and ultrafiltration rate (UFR) using either an open loop system with a single pass of fresh PD fluid, or various external purifications of the spent dialysate. OBJECTIVE: To compare, in patients with various peritoneal transport patterns, fluid and solute removal achieved during a standardized program of CFPD versus two control schedules: nightly intermittent peritoneal dialysis (NIPD) and nightly tidal peritoneal dialysis (NTPD). This study focused on small solute clearances and UFR using only isotonic PD solution (Dianeal PD1 1.36%; Baxter Healthcare, Castlebar, Ireland). The model of fresh dialysate, single pass, was used to optimize solute gradients and to characterize the impact of a continuous flow regimen on peritoneal transport characteristics. METHODS: In a crossover trial, 4-hour CFPD sessions were performed at a fixed dialysate flow rate (100 mL/ minute) in 5 patients being treated with automated PD. A hemofiltration monitor (BM25; Baxter Healthcare, Brussels, Belgium) was adapted to the CFPD technique. The peritoneal cavity was filled through a temporary second catheter and simultaneously drained using the permanent peritoneal access. Fluid and solute removal were compared to data obtained from a control period based on 8-hour sessions of NIPD or NTPD using 13 L of isotonic dialysate. RESULTS: High-flow CFPD enhanced the diffusive transport coefficient compared with the alternative flow regimen in patients ranging from low to high transporters. Weekly creatinine clearance increased from 36.9 L (22.3 - 49.6 L) and 37.3 L (27.5 - 45.0 L) with NIPD and NTPD respectively, to 74.9 L (42.3 - 107.5 L) with CFPD. Mean UFR was 2.44 mL/min with CFPD versus 0.92 and 0.89 mL/min with NIPD and NTPD respectively. The mass transfer area coefficient (MTAC) of creatinine with CFPD was 2.5-fold that obtained from the peritoneal equilibration test data. CONCLUSION: Our results confirm that CFPD is highly effective in increasing fluid and solute removal. Furthermore, consistent with historical data, our findings indicate that the enhanced solute transfer is not due only to steeper solute gradients, but also depends on increased MTAC in a wide range of peritoneum transport characteristics.     

Prone-position ventilation induces sustained improvement in oxygenation in patients with acute respiratory distress syndrome who have a large shunt

OBJECTIVES: Prone-position ventilation (PPV) induces acute improvement in oxygenation in many patients with acute respiratory distress syndrome (ARDS), with some maintaining their oxygenation even after they were returned to the supine position, but it is unclear what clinical factors determine the sustained oxygenation benefit. We hypothesized that patients with ARDS who have a larger shunt would have a better acute and sustained oxygenation response to PPV. DESIGN: Prospective, nonrandomized interventional study. SETTING: Medical and surgical intensive care units, university tertiary care center. PATIENTS: Twenty-two consecutive patients, with ARDS with an average PaO2/FiO2 of 94, were administered PPV for 12 hrs followed by supine-position ventilation for 2 hrs. MEASUREMENTS: Hemodynamic and gas exchange variables were monitored. The shunt was measured as venous admixture at an FiO2 of 1.0, and compliances of the respiratory system, lung, and chest wall were measured by the esophageal balloon technique before PPV, during PPV, and during subsequent supine-position ventilation. MAIN RESULTS: Fourteen patients (64%) responded to PPV, with PaO2/FiO2 increasing by > or =20. These changes were associated with a decrease in chest wall compliance. Responders had significantly shorter time from ARDS to PPV, a lower baseline PaO2/FiO2, and a higher venous admixture. All responders maintained the improvement in oxygenation and had a greater respiratory system compliance after returning to the supine position. Time from ARDS to PPV and baseline lung injury score were negatively associated, whereas chest wall compliance, heart rate, and PaCO2 were positively associated with sustained improvement in oxygenation. CONCLUSIONS: PPV induced acute and sustained improvement in oxygenation in many patients with ARDS. The sustained improvement is more significant if PPV is administered early to patients with a larger shunt and a more compliant chest wall. Measuring venous admixture and chest wall compliance before PPV may help select a subgroup of patients with ARDS who may benefit the most from PPV.     

重型颅脑损伤并发急性呼吸窘迫综合征危险因素分析

目的　探讨重型颅脑损伤并发急性呼吸窘迫综合征 (ARDS)的危险因素。方法对 2 4例重型颅脑损伤并发ARDS患者的临床资料进行回顾性分析 ,分析年龄、性别、GCS评分、肋骨骨折、肺挫伤、血气胸、呕吐误吸、PaO2 /FiO2 等相关因素与急性呼吸窘迫综合征的关系。结果年龄、GCS评分、肋骨骨折、肺挫伤、血气胸、呕吐误吸、PaO2 /FiO2 等因素统计学分析有显著性差异 (P <0 .0 5 )。结论年龄、GCS评分、胸部外伤程度、呕吐误吸是重型颅脑损伤并发急性呼吸窘迫综合征的危险因素 ,PaO2 /FiO2 是判断伤情发展趋势的重要指标。     

小潮气量通气在具有发生急性呼吸窘迫综合征高危因素患者中的应用研究

目的探讨小潮气量通气用于具有急性呼吸窘迫综合征(ARDS)高危因素患者机械通气后的临床疗效。方法选择2014年8月至2016年9月入住本院将重症医学科和传染科监护室的200例急性呼吸衰竭需有创机械通气患者作为研究对象,按单随机化法按进行机械通气先后分成研究组和对照组,各100例。研究组给予小潮气量6~8mL/kg,呼吸末正压5~8mm H2O,对照组气管插管后给予潮气量10~12mL/kg、根据病情呼吸末正压0~5mm H2O。比较通气后患者的氧分压、二氧化碳分压、氧合指数、呼吸力学指标、炎症指标、机械通气指标、住院时间、ARDS发生率、28d病死率。结果研究组患者PaO2和PaO2/FiO2改善效果较对照组更明显(P0.05)。而在pH值和PaCO2指标方面,两组患者治疗后差异无统计学意义(P0.05);肺顺应性增强明显,气道峰压和平台压明显低于对照组,差异有统计学意义(P0.05);治疗后,研究组患者的IL-6水平相比较于对照组显著的降低,差异有统计学意义(P0.05),研究组患者的TNF-α水平也显著低于对照组,差异有统计学意义(P0.05);研究组患者的住院时间、ARDS发生率和28d病死率均显著低于对照组患者,差异具有统计学意义(P0.05)。结论小潮气量通气用于具有ARDS高危因素患者机械通气后,具有减少肺损伤,降低ARDS发生率,降低病死率效果,值得临床广泛应用。     

Choice of optimal respiratory support in acute parenchymatous respiratory failure

The principal goals of respiratory therapy for acute respiratory failure are to correct gas exchange and to lower respiratory performance. In acute lung lesion syndrome (ALLS) and acute respiratory distress syndrome (ARDS), the oxygenation index (PaO2/FiO2) reflects the degree of alveolar-capillary membrane damage. The changes in PaO2/FiO2 between 400 to 300 at adequate ventilation can be interpreted as occult alveolar-capillary insufficiency. The principle of power saving in ALLS/ARDS is to choose a respiratory support regimen that may ensure oxygenation safety by eliminating the excess work of respiration. The ratio of PaO2/FiO2/VO2 is proposed to consider to be a criterion for the effectiveness of respiratory support in ALLS/ARDS and a marker of energy deficiency. It has been established that the function of the alveolar-capillary membrane is not impaired with the PaO2/FiO2 ratio of more than 1.5 and the ratio of less than 1.0 is typical of the severe course of the severe course of ARDS and suggests both alveolar-capillary membrane damage and energy deficiency.     

Pulmonary extravascular water in patients with acute respiratory failure

The purpose of the investigation was to study pulmonary extravascular water levels and pulmonary vascular permeability (PVP) in the pathogenesis of acute respiratory failure (ARF)/acute respiratory distress syndrome (ARDS). Twenty-nine patients with ARF/ARDS and 10 healthy volunteers were examined. Central hemodynamics and oxygen transport were explored, by using a Swan-Ganz catheter. Intrathoracic volemic parameters were studied by the transpulmonary thermodilution technique. PVP was assessed by the pulmonary 67Ga-labelled transferrin leakage index. Plasma colloid osmotic pressure (COP) was measured on an osmometer. In most patients with ARF/ARDS, the pulmonary extravascular water index (PEVWI) was found to be higher (mean 16.9 +/- 1.5 ml/kg). At the same time its value was not greater than 10 ml/kg in 7 (24%) of 29 patients. There were no correlations between PEVWI and PaO2/FiO2 and between pulmonary extravascular water and AaDO2. The PVP index (PVPI) measured by transpulmonary thermodilution was 3.2 +/- 0.2, it being normal in 13 (45%) out of 29 patients. The pulmonary 67Ga-transferrin leakage index was higher in all the patients than in healthy individuals (23.2 +/- 2.9 x 10(-3) vs 5.7 +/- 9.9 x 10(-3)) and correlated with PaO2/FiO2 (r = 0.71; p = 0.01). In patients with ARF/ARDS, COP was lower (19.9 +/- 0.7 mm Hg). There were correlations between COP and PEVWI (r = -0.34; p = 0.01), COP and PVPI (r = -0.40; p = 0.044), COP and PaO2/FiO2 (r = 0.35; p = 0.02). PEVWI correlated with the COP-pulmonary wedge pressure gradient (r = -0.45; p = 0.0024). Hypoxemia correlated with intrapulmonary shunt (Qs/Qt). There was no relationship between Qs/Qt and PEVWI in the group as a whole. According to the ratio of Qs/Qt to PEVWI, the patients were divided into 2 groups. Group 1 comprised 11 patients with the ratio < or = 2; Group 2 included 18 patients with the ratio > or = 2, i.e. with an unproportional shunt enlargement as to the severity of pulmonary edema. A correlation between Qs/Qt and PEVWI was found in both groups: r = 0.82; p = 0.001 with the ratio < or = 2 and r = 0.48; p = 0.04 with the ratio > or = 2. Diverse causes of shunt formation were histologically detected. Thus, pulmonary edema was not identified in 24% of patients with ARF/ARDS. Arterial hypoxemia is associated with the increase in the shunt, but, in a portion of patients, the shunt was caused with atelectasis unassociated with pulmonary edema. Increased pulmonary permeability for transferrin is detectable in ARF/ARDS irrespective the severity of pulmonary edema. The pathogenetic features of lung lesions should be taken into account while choosing a treatment for ARF/ARDS.     

心内直视手术后长时间呼吸机支持的危险因素分析

目的　分析心内直视手术后影响患者呼吸机辅助时间的危险因素 ,提高心内直视手术后呼吸并发症的诊治水平。方法　回顾性分析我院在 1995年 1月— 2 0 0 3年 8月期间长时间呼吸机辅助呼吸的 5 0例成人患者的临床资料 ,并用多因素线性回归分析模型评价各影响因素的作用大小。结果　本组患者年龄 14～6 5岁 ;体质量 2 8～ 80 kg;男性 2 8例 ,女性 2 2例 ;平均转流时间 (15 6 .38± 5 2 .0 2 ) m in;术后呼吸机辅助时间为 (6 2 .86± 2 2 .5 5 ) h;病死率为 18.0 %。与对照组相比 ,长时间呼吸机辅助呼吸组患者术前心功能差(P<0 .0 0 1) ,体外循环时间与阻断时间长 (P<0 .0 0 1) ,术后动脉血氧分压 (Pa O2 )及氧合指数 (Pa O2 /Fi O2 )低(P<0 .0 0 1) ,而术后肺泡动脉血氧分压差 (A a DO2 )高 (P<0 .0 0 1) ,肺内分流 (Qs/Qt)增大 (P<0 .0 0 1) ,术后肺动态顺应性 (PCD)无明显区别 ,术后引流量较多 (P<0 .0 0 1) ,术后心肌酶谱水平高 (P<0 .0 0 1) ,术后并发症的发生率也较高 (P<0 .0 0 1)。经多因素线性回归分析结果显示 ,术后呼吸机辅助呼吸时间与患者术前心功能、术中转流时间、术后 Pa O2 /Fi O2 、术后心肌酶谱水平及术后引流量明显相关。结论　心内直视手术患者术前心功能差、术中转流时间长、术中心肌     

俯卧位通气联合呼气末正压治疗急性呼吸窘迫综合征家猪的疗效研究

目的 探讨俯卧位通气联合呼气末正压(PEEP)治疗急性呼吸窘迫综合征(ARDS)的疗效及其机制.方法 12头家猪静脉注射油酸建立ARDS模型,分为仰卧位组和俯卧位组,均给予0(ZEEP)、10(PEEP10)、20 cm H2O(PEEP20,1 cm H2O=0.098 kPa)PEEP的机械通气15 min,监测家猪血流动力学、肺气体交换和呼吸力学指标;处死动物观察肺组织病理学变化.结果 俯卧位组ZEEP、PEEP10时氧合指数(PaO2/FiO2)明显优于仰卧位组[ZEEP:(234.00±72.55)mm Hg比(106.58±34.93)mm Hg,PEEP10:(342.97±60.15) mm Hg比(246.80±83.69)mm Hg,1 mm Hg=0.133 kPa,P均<0.05];PEEP20时两组PaO2/FiO2差异无统计学意义(P>0.05).PEEP10时两组肺复张容积(RV)差异无统计学意义(P>0.05);但PEEP20时俯卧位组RV显著高于仰卧位组[(378.55±101.80)ml比(302.95±34.31)ml,P<0.05].两组间心率(HR)、平均动脉压(MAP)、心排血指数(CI)、呼吸系统顺应性(Cst)及动脉血二氧化碳分压(PaCO2)差异均无统计学意义(P均>0.05);仰卧位组背侧肺组织的肺损伤总评分明显高于俯卧位组[(12.00±1.69)分比(6.03±1.56)分,P<0.05].结论 俯卧位通气联合合适的PEEP可改善ARDS家猪氧合,并且不影响血流动力学和呼吸力学,肺组织损伤的重新分布可能是其机制之一.     

Efficiency of inhaled nitric oxide as rescue therapy during severe ARDS: Survival and factors associated with the first response

PURPOSE: The purpose of this study was to determine if the response to inhaled nitric oxide (NO) as salvage therapy is an independent factor for survival in adult respiratory distress syndrome (ARDS) patients and to identify the factors that predict the response to inhaled NO during ARDS. MATERIALS AND METHODS: This was a multicenter, 2-year retrospective, clinical study in five university surgical or medical intensive care units, including all consecutive patients with ARDS in whom inhaled NO was tried. Clinical data (medical history, diagnoses), general severity scores (SAPS II, OSF), biological data, radiological and hemodynamic data at admission, at the beginning of the ARDS, and under treatment with inhaled NO were recorded. The NO response was defined as the variation of PaO2/Fio2 ratio before initiation and after 30 minutes of NO inhalation (VarPaO2/FiO2). RESULTS: Ninety-three patients aged 49 +/- 18 years were studied. Mean SAPS II was 45 +/- 16. Before the beginning of inhaled NO, PaO2/Fio2 ratio was 95 +/- 53 mm Hg and lung injury score 2.7 + 0.3. VarPao2/Fio2 when NO was started (11 +/- 4 ppm) was 26 +/- 44.5 mm Hg (median 17 mm Hg). Intensive care unit mortality was 74%. None of the parameters studied were predictors of response to inhaled NO, although there was a tendency for the youngest patients with the more severe hypoxemia to have a better response. Response to first inhaled NO test (VarPaO2/FiO2) was univariately associated with survival (Survivors: 45 +/- 44 mm Hg vs. Nonsurvivors: 20 +/- 43 mm Hg, P = .01), but this difference disappeared after adjusting for other prognostic factors (P = .16) selected by multivariate analysis. Finally, inhaled NO was continued for more than 1 day for 75 patients, and definitively stopped for 18 patients. Intensive care unit mortality (73% vs. 78%) was not different between these groups (P = .25, Log-rank test). CONCLUSIONS: We conclude that (1) efficacy of inhaled NO in improving oxygenation was moderate and difficult to predict, (2) response to first NO inhalation was not associated with prognosis, and (3) treatment of the most severe ARDS patients with inhaled NO did not influenced their intensive care unit survival.     

无创正压通气治疗急性呼吸窘迫综合征的前瞻性队列研究

目的 观察和评价无创正压通气(NPPV)对急性呼吸窘迫综合征(ARDS)的疗效和安全性.方法 采用前瞻性队列研究,分析2004年1月-2007年12月北京朝阳医院呼吸重症监护病房(RICU)使用NPPV治疗ARDS患者的临床资料.结果 ①31例患者纳入本研究,其中男23例,女8例;年龄20～76岁,平均(49±17)岁;NPPV前急性生理学与慢性健康状况评分系统Ⅰ(APACHE Ⅰ)评分(14±8)分,氧合指数(PaO2/FiO2)(123±32)mm Hg(1 mm Hg=0.133 kPa).②NPPV成功率为74.2%(23/31),非肺部感染所致ARDS的成功率显著高于肺部感染所致ARDS(100%比60%,P=0.017).③与NPPV前相比,成功组NPPV治疗后2 h及24 h的心率(HR)、呼吸频率(RR)及PaO2/FiO2均有显著改善(P均<0.01),而失败组上述指标不但无显著改善,尚伴有动脉血二氧化碳分压(PaCO2)逐渐升高(P<0.05).患者均无NPPV相关的严重并发症.结论 对于无NPPV禁忌的ARDS患者,NPPV可作为一线呼吸支持手段;但对于在短期应用NPPV后生命体征及动脉血气无显著改善者,尤其是肺部感染诱发ARDS时应及早改为有创通气.     

纤维支气管镜在肝移植术后急性肺损伤治疗中的应用

目的 回顾性探讨床旁纤维支气管镜(纤支镜)在肝移植术后急性肺损伤(ALI)治疗中的临床应用价值.方法 将58例肝移植术后各种原因导致的ALI患者按是否采用纤支镜干预治疗分为纤支镜治疗组(36例)和常规治疗组(22例),通过比较两组重症加强治疗病房(ICU)停留时间、机械通气时间、ALI病死率、急性呼吸窘迫综合征(ARDS)进展率及其病死率,以及纤支镜使用前后的动脉血气分析变化等,评价纤支镜治疗肝移植术后ALI的临床疗效.结果 与常规治疗组比较,纤支镜治疗组的ICU停留时间[(11±4)d比(16±4)d]、机械通气时间[(9±5)d比(14±5)d]均明显缩短(P均＜0.01),ALI病死率(11.1%比36.4%)及ARDS进展率(27.8%比54.5%)明显降低(P＜0.05和P＜0.01),而ARDS病死率无显著变化[40.0%(4/10)比66.7%(8/12),P＞0.053;纤支镜治疗后动脉血氧分压(PaO2)、动脉血二氧化碳分压(PaCO2)、动脉血氧饱和度(SaO2)及氧合指数(PaO2/FiO2)均明显好转,与治疗前比较差异均有统计学意义(P均＜0.01).结论 纤支镜是肝移植术后ALl安全、有效的治疗方法,值得推广.     

Inhalation of nitric oxide in severe lung failure

Despite intensive therapeutic efforts, adult respiratory distress syndrome (ARDS) is still associated with a lethality ranging from 50 to 80%. Besides hypoxemia, fatal outcome is caused by myocardial insufficiency due to a progressive decrease in pulmonary vascular conductance. Inhalation of NO can selectively dilate pulmonary vessels in ventilated lung regions, thus increasing mean pulmonary artery conductance and decreasing venous admixture. This study determines the effects of NO inhalation in patients with severe ARDS on pulmonary gas exchange, haemodynamics and mortality. Twenty surgical patients (mean age 50.3 +/- 9.25 years) with severe ARDS (Murray score 3.4 +/- 0.3) were treated with variable concentrations of NO during mechanical ventilation with continuous positive pressure. Pulmonary artery catheters were used to measure pressures, flow and venous admixture. Mortality with NO inhalation was compared with that of previous ARDS patients (n = 20) who had not received NO. Mean duration of NO inhalation was 120.1 +/- 33.12 hours (n = 20) (range 40 to 254 hours). Mean NO concentration during the first hour of delivery was 18.5 +/- 3.88 ppm. Sixteen patients had FiO2 of 1.0 when NO was started. Within the first hour of NO inhalation, the PaO2/FiO2 ratio increased from 82.1 +/- 10.28 to 124.6 +/- 28.18. Eighteen patients were responders. Mean ventilatory pressure was lowered. Oxygenation improvement was most marked during the first 36 hours and then gradually declined. Despite the significant increase in NO related oxygenation, pulmonary artery pressures did not consistently decrease. Sixteen patients in the NO group died. In the group without NO 15 patients died. Compared with ARDS patients of similar severity not receiving NO, the NO-treated patients had the same lethality. In severe ARDS, oxygenation significantly improves with the initiation of NO inhalation, but this effect declines over time. With NO, FiO2 and ventilatory pressures can be lowered. Whether the theoretically reduced oxygen toxicity and the reduced invasiveness of mechanical ventilation with NO reduces patient mortality must be determined in larger patient groups.     

吸入氧浓度对急性呼吸窘迫综合征诊断的影响

目的 探讨吸入氧浓度(FiO2)对急性呼吸窘迫综合征(ARDS)患者氧合指数(P/F=PaO2/FiO2)的影响及其临床意义.方法 采用前瞻性研究,选择16例PEEP≥5 cmH2O(1 mmHg=0.098 kPa)时P/F为100～200 mmHg(1 mmHg=0.133 kPa)需机械通气的ARDS患者,实施肺复张(BIPAP,PH 40 cmH2O,40 s)后维持基线通气,稳定30 min后,按随机顺序设定FiO2为0.5,0.6,0.7,0.8,0.9和1.采用SPSS 13.0统计软件比较不同FiO2下患者呼吸力学、血气及血流动力学各指标的变化及其相关性.结果 随FiO2增加P/F逐渐增加,FiO2增加至0.7以上,P/F增加更加明显,FiO2分别为0.5和1.0两组进行比较,P/F的变化为24.70%±23.36%;6例(37.5%)患者FiO2为0.5时P/F＜200,而FiO2为1.0时P/F＞200;FiO2与Qs/Qt呈负相关(r=-0.390,P=0.027),吸入氧浓度越高,分流越小,FiO2为0.5和1.0时△Qs/Qt与△P/F呈正相关(r=0.82,P=0.005).结论 吸入氧浓度影响ARDS患者的氧合指数,从而可能影响ARDS的诊断,这与其对肺内分流的影响有关.

Abstract：

Objective To investigate the influence of inspired oxygen fraction (FiO2) on the ratio of PaO2/FiO2(P/F) during the implementation of lung protective ventilation strategy in patients with acute respiratory distress syndrome(ARDS) in order to unravel its clinical significance. Method This was a prospective study of 16 selected patients with ARDS treated with mechanical ventilation ( MV ) to get ratio of P/F in range of 100 to 200 by PEEP≥5 cmH2O and high inspired oxygen. After lung recruitment maneuvers by BiPAP with high pressure (PH) of 40 cmH2O for40 s, the MV was maintained the basic requirement for stabilizing the patients for 30 minutes. A series of FiO2 were set at fractions of 0.5,0.6,0.7,0.8,0.9 and 1in random sequence, and the changes of respiratory mechanics, blood gas and hemodynamics under the different concentrations of FiO2 were analyzed by using SPSS version 13.0 software. Results ( 1 ) The ratio of P/F increased as FiO2 increased, and it's significant as FiO2 increased to 0.7 or above. As the fractions of FiO2 were set at 0.5 and 1. O, the ratios of P/F changed in 24.70% ± 23.36% respectively. ( 2 ) Of them,6 patients ( 37.5% ) treated with FiO2 set at 0.5 had the ratio of P/F ＜ 200, and the fraction of FiO2 was increased to 1.0, the P/F ＞ 200. (3) FiO2 and Qs/Qt were negatively correlated ( r = - 0.390, P = O. 027 ),the higher inspired oxygen fraction, the lower shunt. When the fractions of FiO2 were set at 0.5 and 1.0 ,there was a positive correlation between △Qs/Qt and △P/F( r = 0.82, P = 0.005 ). Conclusions The inspired oxygen fraction affects the ratio of P/F, which may be resulted from shunt and it may influence the diagnosis of ARDS.     

危重病患者并发急性呼吸窘迫综合征173例分析

目的提高对危重病患者发生急性呼吸窘迫综合征(ARDS)的认识.方法分析了137例ARDS患者的临床资料,病人至少符合PaO2＜8.0kPa(60mmHg)或氧合指数PaO2/FiO2＜40kPa(300mmHg).结果173例危重病患者中并发全身炎症反应综合征(SIRS)126例(72.8%),并发多器官功能障碍综合征(MODS)79例(45.7%),全组中死亡94例(54.3%).以呼吸衰竭作为第一位死因者30例(31.9%),以MODS作为第一位死因者52例(55.3%),其它原因死亡者12例(12.8%).结论在治疗中应积极救治原发疾病,动态监测动脉血气,计算PaO2/FiO2,同时注意保护和监测其它重要脏器的功能,以免发生MODS,提高ARDS的救治水平.     

连续血液净化治疗急性呼吸窘迫综合征疗效分析

目的:探讨连续血液净化(CBP)治疗急性呼吸窘迫综征(ARDS)的疗效。方法:在常规治疗ARDS的基础上,以日间连续静脉血液滤过(CVVH)模式给予治疗。结果:CBP治疗后动脉血氧合指数(PaO2/FiO2)呈进行性上升,治疗4h氧合指数明显升高。机械通气时间2d～16d,平均5.5d,CVVH时间48h～240h,平均84h,存活16例,死亡6例,其中自动出院死亡2例,死亡率28.0%。结论:联合应用CBP治疗ARDS疗效肯定,是具有前景的治疗ARDS的方法。     

Noninvasive ventilation of the lungs in the treatment of acute respiratory failure in immunocompromised patients

The purpose of this study was to evaluate the efficiency and place of noninvasive ventilation of the lungs (NVL) in the treatment of hypoxemic acute respiratory failure (ARF) in patients with tumorous diseases of the blood. The study was carried out in 12 patients (3 men and 9 women) with tumorous diseases of the blood system, in whom NVL was used for treating ARF. Central hemodynamic and oxygen transport parameters were studied using Swan-Hanz catheter. NVL was uneventfully carried out in 5 (41.7%) of 12 patients (group 1). Group 2 consisted of 7 patients intubated after the beginning of NVL: 2 had to be transferred to forced ventilation of the lungs (FVL) because of loss of consciousness and 5 because of augmenting severity of ARD. All patients transferred to FVL died. During the first 3 h of NVL, oxygen delivery increased from 371.3 +/- 84.9 to 443.9 +/- 92.7 gm/m2 and oxygen consumption from 123.9 +/- 35.9 to 173.5 +/- 34 m/m2, oxygen alveolar-arterial difference decreased from 400.8 +/- 165.3 to 210 +/- 57.5 mm Hg, pulmonary shunt from 41.8 +/- 11.9 to 19 +/- 7.9%, PaO2/FiO2 from 140.4 +/- 210 +/- 84.9, left-ventricular stroke index increased from 38.2 +/- 14.9 to 50.6 +/- 21.8 ml/m2, left-ventricular output index from 37 +/- 19.5 to 47.4 +/- 23.7 gm/m2, and heart rate decreased from 119.2 +/- 17.5 to 111.4 +/- 23.8 min-1. In group 2 greater fraction of inhaled oxygen and higher positive pressure at the end of inspiration were required than in group 1. Heart rate and oxygen alveolar-arterial difference were higher in group 2. Side effects of NVL were skin maceration, hematomas on the bridge of the nose, and conjunctivitis. A specific complication associated with thrombocytopenia was the hemorrhagic syndrome (nasal bleeding, hemorrhagic stomatitis). Hence, NVL is the first stage of respiratory support in hypoxemic ARF. In immunocompromised patients NVL is effective only in cases when the cause of damage to the lung is rapidly diagnosed and effective pathogenetic therapy promptly started.     

Nebulized prostacyclin (PGI2) in acute respiratory distress syndrome: impact of primary (pulmonary injury) and secondary (extrapulmonary injury) disease on gas exchange response

OBJECTIVES: To examine the hypothesis that the response to inhaled prostacyclin (PGI2 on oxygenation and pulmonary hemodynamics may be related to different morphologic features that are supposed to be present in acute respiratory distress syndrome (ARDS) originating from pulmonary (primary ARDS [ARDS(PR)]) and from extrapulmonary disease (secondary ARDS [ARDS(SEC)]). DESIGN: Prospective, nonrandomized interventional study. SETTING: Multidisciplinary intensive care unit, secondary care center. PATIENTS: Fifteen consecutive, mechanically ventilated patients with ARDS and severe hypoxemia, defined as PaO2/FIO2 of <150 torr at the time of admission. INTERVENTIONS: After an initial stable period of at least 60 mins, patients received nebulized PGI2 in 15-min steps; the drug was titrated to find the dose with the best improvement of PaO2, starting with 2 ng/kg/min up to an allowed maximum dose of 40 ng/kg/min. MEASUREMENTS AND MAIN RESULTS: Blood gas, gas exchange, and hemodynamic measurements were performed at the following time points: a) baseline; b) during the optimal or maximum dose of PGI2; and c) 1 hr after withdrawal of the drug. Patients underwent a computed tomographic (CT) scan using a basal CT section to compute the mean CT numbers and the density histogram. Patients were considered responders to PGI2 if an increase in PaO2 of > or =7.5 torr or an increase in PaO2/FIO2 ratio of > or =10% occurred. For the group as a whole, mean pulmonary artery pressure decreased from 32 +/- 1 to 29 +/- 1 mm Hg during PGI2 nebulization, whereas pulmonary vascular resistance decreased 1 hr after withdrawal of nebulization from 177 +/- 18 to 153 +/- 16 dyne x sec/cm5; oxygenation did not change significantly. Eight patients responded to PGI2 nebulization on oxygenation (all were in the ARDS(SEC) subgroup), whereas seven did not (all but one were in the ARDS(PR) subgroup). Among the physiologic variables examined to assess any difference between the two ARDS groups at time of PGI2 nebulization, there was a significant difference concerning the mean CT density number, which was -445 +/- 22 Hounsfield Units in the ARDS(SEC) group and -258 +/- 16 Hounsfield Units in the ARDS(PR) group. In patients presenting with an ARDS(PR), PGI2 induced a reduction in PaO2/FIO2 and a reduction in PaO2 from 87 +/- 2 to 79 +/- 2 torr, whereas in patients with an ARDS(SEC) there was an increase in PaO2/FIO2 and in PaO2 from 76 +/- 4 to 84 +/- torr with a decrease in mean pulmonary artery pressure. CONCLUSIONS: Based on the data from this study, the clinical recognition of the two types of the syndrome together with the CT number frequency distribution analysis may be associated with a prediction of the PGI2 nebulization response on oxygenation.