稳定期重度慢性阻塞性肺疾病吸烟与不吸烟患者运动心肺功能的对比研究

目的 通过比较吸烟组、戒烟组及未吸烟组稳定期重度慢性阻塞性肺疾病(COPD)患者的相关肺功能指标及心肺运动试验结果,探讨吸烟对COPD患者运动心肺功能的影响.方法 将121例处于稳定期的重度COPD男性患者分为三组:吸烟组(n=47例),戒烟组(戒烟时间≥6月,n=46例)及未吸烟组(n =28例),并分别进行常规肺功能检测(pulmonary function test,PFT)及心肺运动试验(cardiopulmonary exercise testing,CPET),测定相关肺通气功能参数、心肺运动功能参数,并将三组间数据进行方差分析.结果 ①三组的PFT测定结果显示,FEV1、FEV1％ pred、FEV1/FVC、TLC、DLCO三组间比较差异无统计学意义(P＞0.05),而吸烟组的IC值[(1.43±0.5)L]显著低于戒烟组[(1.51±0.6)L]与未吸烟组[(1.64±0.6)L](P＜0.05),吸烟组的RV、RV/TLC[(4.43±1.5)L,(57.2±9.8)％]显著低于戒烟组[(4.1±1.3)L,(54.3±7.6)％]与未吸烟组[(3.4±1.2)L,(51.5±7.9)％](P＜0.05);②CPET测定结果显示,三组间peak Load差异无统计学意义(P＞0.05),吸烟组的(V)O2/kg、peak(V)E、dO2/dW1、peak O2 pulse、VD/VT[(15.4±4.6)ml·min-1·kg-1,(33.1±7.6) L/min,(8.1±0.8)ml· min-1·watt-1·(8.0±2.4)ml/beat,(39.4±7.0)％]与戒烟组[(17.2±4.8)ml·min-1·kg-1,(34.3±79.1)L/min,(8.7±0.7)ml·min-1·Watt-1,(9.8±2.7)ml/beat,(35.1±6.7)％]、未吸烟组[(18.7±4.0) ml· min-1 ·kg-1,(38.6±7.7)L/min,(9.1±1.5) ml·min-1·watt-1,(10.8±2.7)ml/beat,(32.4±6.1)％]比较,差异有统计学意义(P＜0.05);吸烟组的peak(V)O2、peak(V)O2％ pred、lowest(V)E/(V) CO2[(876.6±384.3)ml/min,(54.3±15.6)％,(32.5±3.2)]与戒烟组[(1 086.9±305.1) ml/min,(63.4±18.4)％.(30.3±3.4)]、未吸烟组[(1 299.5±284.8) ml/min,(71.1±17.6)％,(28.8±2.9)]间比较差异有统计学意义(P＜0.01);③吸烟指数与IC、TLC、peak(V)O2、peak(V)O2/Kg、peak(V)E呈负相关(P＜0.01);与peak(V)O2、peak (V)E、lowest(V)E/(V) CO2、VD/VT呈正相关(P＜0.01).结论 吸烟能明显影响COPD患者运动心肺功能,降低运动耐量,且其影响程度与吸烟量的多少相关.戒烟对于COPD患者仍有较大意义.     

戒烟时间对稳定期重度慢性阻塞性肺疾病患者运动耐力的影响

目的 通过比较重度慢性阻塞性肺疾病(COPD)男性患者戒烟6个月时与戒烟12个月时两次测得相关肺功能指标及心肺运动试验(cardiopulmonary exercise test,CPET)结果,探讨戒烟时间对稳定期重度COPD患者运动耐力的影响.方法 随访52例处于稳定期的重度COPD男性患者,分别于其戒烟6个月时及戒烟12个月时两次进行静态常规肺功能(pulmonary function test,PFT)及CPET,测定相关肺通气功能参数、心肺运动功能参数,并将两次测得数据进行配对样本t检验.结果 ①此52例COPD患者于戒烟6个月时和戒烟12个月时两次测得的PFT结果显示,FEV1、FEV1％pred、FEV1/FVC、D(1.)CO两组间比较差异无统计学意义(P＞0.05).戒烟12个月时的IC[(2.21±0.62)L]高于戒烟6个月时的IC[(1.83±0.47)L],差异有统计学意义(P＜0.05).戒烟12个月时的RV[(4.02±0.82)L]、TLC[(7.30±1.21)L]、RV/TLC[(51.43±7.67)％]均低于戒烟6个月时的RV[(4.75±0.26) L]、TLC[(7.71±0.84)L]、RV/TLC[(56.33±8.79)％],差异均有统计学意义(P＜0.05);②CPET测定结果显示,此52例COPD患者戒烟12个月时的Peak Load[(91.21±15.12)W]、Peak(v)O2[(1 327.21±281.42) ml/min]、Peak(v)O2 ％pred[(63.07±17.15)％]、Peak(v)O2/kg[(21.58±4.13)ml·min-1·kg-1]、Peak(v)E[(38.33±8.79)L/min]、dO2/dW1[(8.67±0.73)ml·min-1·watt-1]、Peak O2 pulse[(10.62±2.67)ml/beat]均高于戒烟6个月时的Peak Load[(81.26±16.32)w]、Peak (v)O2 [(1075.18±276.45) ml/min]、Peak(v)O2 ％pred[(54.13±16.14)％]、Peak(v)O2/kg[( 17.49±4.37)ml·min-1·kg-1]、Peak(v)E[(34.29±7.12)L/min]、dO2/dW1[(8.51±0.72)ml·min-1·watt-1]、Peak O2 pulse[(9.57±2.47)ml/beat],差异有统计学意义(P＜0.05)；戒烟12个月时的Lowest(v)E/(v)CO2[(28.38±3.4)]低于戒烟6个月时的Lower(v)E/(v)CO2[(31.5±3.21)],差异有统计学意义(P＜0.05);③PFT中IC改善值与CPET中Peak(v)O2、Peak(v)O2/kg、Peak(v)E、Lowest(v)E/(v)CO2的改善值有良好的相关性,而FEV1的改善值与上述CPET的参数改善无显著相关.结论 戒烟时间的长短能影响COPD患者综合心肺能力和运动耐量,戒烟对于重度COPD患者仍有较大意义.IC值对于预估COPD患者的运动耐力受损程度有较大意义.     

摄氧效率与慢性阻塞性肺疾病稳定期患者运动耐力的相关性

目的 探讨慢性阻塞性肺疾病(简称慢阻肺)患者的摄氧效率特点,并分析其对于慢阻肺患者运动耐力的影响.方法 选择2009年8月至2012年8月在上海市肺科医院呼吸科就诊的慢阻肺稳定期患者59例,其中男53例,女6例;年龄42 ～80岁,平均(62±9)岁;按照病情严重程度再分为Ⅰ级组15例、Ⅱ级组16例、Ⅲ级组19例、Ⅳ级组9例.同年龄段健康志愿者29名为对照组.对所有受试者进行常规肺功能检测及斜坡式功率递增症状限制性心肺运动试验,采用逐次呼吸法对呼吸交换参数进行收集和分析.计数资料用构成比表示,两组间比较采用t检验和x2检验,多组间比较采用单因素方差分析,相关分析采用Pearson相关性检验.结果 慢阻肺组摄氧效率斜率(OUES)和摄氧效率平台(OUEP)[(1.9 ±0.3) L· min-1·lg(L·min-1)-1和(31 ±5) ml/L]均显著低于对照组[(2.2±0.4) L·min-1 ·lg(L· min-1)-1和(35 ±4) ml/L],差异均有统计学意义(t值分别为4.57和3.39,均P＜0.01);Ⅰ级组OUES、OUEP和无氧阈时的摄氧效率[(2.09±0.31)L·min-1·lg(L·min-1)-1、(34±5)和(34±5)ml/L]与对照组[(2.23 ±0.39)L·min-1·lg(L·min-1)-1、(35±4)和(34 ±4) ml/L]的差异无统计学意义(t值为0.36 ～ 1.49,均P＞0.05);Ⅱ～Ⅳ级组OUES[(2.05 ±0.26)、(1.76±0.28)和(1.63 ±0.19)L·min-1·lg(L·min-1)-1-]均显著低于对照组[(2.23±0.39) L· min-1·lg(L· min-1)-1],差异均有统计学意义(t值为2.42～5.26,均P＜0.05);Ⅱ～Ⅲ级组OUEP和无氧阈时的摄氧效率[(31±4)和(31±5)ml/L、(29 ±5)和(29 ±5) ml/L]均显著低于对照组[(35±4)和(34 ±4) ml/L],差异均有统计学意义(t值为2.18～4.83,均P＜0.05);慢阻肺组OUES、OUEP和无氧阈时的摄氧效率与运动耐力(峰值摄氧量占预计值％)均呈正相关(r值为0.500 ～0.625,均P＜0.01).结论 慢阻肺患者的摄氧效率显著低于健康人,且与患者的运动耐力呈显著正相关.     

慢性阻塞性肺疾病患者运动能力与通气效率的相关性分析

目的:通过分析二氧化碳通气当量和运动能力的关系,探讨稳定期慢性阻塞性肺疾病(COPD)患者运动中通气效率与最大运动能力的相关性。方法:选取54例稳定期COPD患者,行运动心肺功能测试,实时监测摄氧量(VO2)、分钟通气量(VE)和二氧化碳排出量(VCO2),根据公式:EqCO2=VE/VCO2计算得出静态二氧化碳通气当量(EqCO2rest)、无氧阈时二氧化碳通气当量(EqCO2at)和最大运动状态下的二氧化碳通气当量(EqCO2max)。结果:1.EqCO2rest、EqCO2at及EqCO2max呈递减趋势,差异有统计学意义(P=0.001)。2.EqCO2at与最大摄氧量(VO2max)(r=-0.294,P<0.05)、EqCO2max与VO2max(r=-0.301,P<0.05)均呈负相关;EqCO2rest与最大摄氧量占预计值的百分比(VO2max/Pred)呈负相关(r=-0.345,P<0.05)。3.肺功能GOLD 3级患者(21例)的VO2max(15.99±3.39)mL·min-1·kg-1明显低于GOLD 2级患者(25例)的VO2max[(18.88±5.36)mL·min-1·kg-1,P=0.038]。两组的EqCO2rest、EqCO2at及EqCO2max差异无统计学意义。结论:稳定期COPD患者运动中通气效率呈进行性下降趋势,这可能是导致其运动能力下降的重要因素之一。     

高血压及左心室肥厚患者的心肺运动功能

目的 评估高血压及伴左心室肥厚(LVH)患者心肺运动功能改变并探讨LVH对心脏贮备功能的影响.方法 对70例原发性高血压(EH)患者根据超声心动图测定的左心室质量指数(LVMI)分为LVH组和非LVH组,选健康体检者为对照组.应用内置同步12导联心电图的运动心肺功能仪测定和比较各组在分级递增运动后达无氧阈(AT)和最大摄氧量(VO2max)时的代谢当量(METs),摄氧量(VO2),公斤体重摄氧量(VO2/kg),和每搏摄氧量(VO2/HR).结果 (1)在达AT值时,EH并LVH组和非LVH组METs和VO2/kg均低于对照组[METs:3.57±0.8和4.34±1.47比5.21±1.45,P<0.01;VO2/kg:(12.38±2.85)ml·min-1·kg-1和(14.42±4.33)ml·min-1·kg-1比(18.48±4.52)ml·min-1·kg-1,P<0.01],EH并LVH组的降低较非LVH组差异也有统计学意义(P<0.05).(2)在VO2max时,EH并LVH组和非LVH组METs和VO2/kg均低于对照组[METs:4.94±1.24和5.90±1.51比6.96±1.85;VO2/kg:(17.20±4.34)ml·min-1·kg-1和(20.41±4.59)ml·min-1·kg-1比(24.04±5.21)ml·min-1·kg-1,P均<0.01],EH并LVH组的降低较非LVH组差异也有统计学意义(P<0.05).(3)经相关分析显示,EH并LVH组LVMI与VO2/kg呈显著负相关(在AT值R=-0.40,在VO2max值R=-0.31,P<0.01).结论 EH患者心肺运动指标METs和VO2/kg降低,运动耐量受损,并与LVMI增高相关.提示EH患者心脏贮备功能下降.     

递增心肺运动试验的风险与防控

目的 探讨递增心肺运动试验中的危险信号及应采取的应对措施.方法 198例受试者进行心肺运动至症状自限,同步实时测定摄氧量、二氧化碳排出量,监测血氧饱和度、心电图和血压,慢性阻塞性肺疾病(COPD)患者于运动前后测定血气分析.结果 155例受试者运动至最大耐受量,43例因出现危险信号而终止运动.危险信号包括:血氧饱和度低于88%(14例);收缩压升高或降低(3例);心律失常(16例);缺血性ST-T改变(10例).COPD患者运动高峰时PaO2轻度降低,从(91.58±9.46)mm Hg降至(88.92±13.66)mm Hg,但差异无统计学意义,运动时的PaCO2较静态时轻度增高,分别为(43.05±3.16)mm Hg和(40.64±4.26)mm Hg,差异有统计学意义(P=0.003).结论 只要我们在运动试验中进行监测,出现危险信号时及时终止运动,运动试验对于多数患者还是一个安全的检查.     

死腔分数导向急性呼吸窘迫综合征呼气末正压选择的临床研究

目的 探讨早期急性呼吸窘迫综合征( ARDS)患者采用死腔分数法选择呼气末正压(PEEP)的可行性.方法 选23例机械通气的早期ARDS患者行持续肺膨胀手法充分肺复张,PEEP递减过程中分别采用最小死腔分数法、最大顺应性法、最佳氧合法选择最佳PEEP,观察不同方法选择的PEEP对患者氧合、解剖死腔容积(VD)/潮气容积(VT)、静态肺顺应性(CLst)和功能残气量(FRC)等的影响.结果 最小死腔分数法[(10.1±2.8)cm H2O(1 cm H2O =0.098 kPa)]和最大顺应性法[(11.3±2.5) cmH2O]选择的最佳PEEP间差异无统计学意义(P＞0.05),均明显低于最佳氧合法[(15.0±3.4) cm H2O,P＜0.05].最小死腔分数法选择PEEP机械通气时患者VD/VT(0.53±0.09)较基础状态(0.59±0.09)明显下降,但最大顺应性法和最佳氧合法选择的PEEP机械通气时VD/VT较基础状态未见明显变化.最小死腔分数法选择的PEEP,其氧合指数明显低于最佳氧合法[(288±123) mm Hg(1 mm Hg=0.133 kPa)比(356±119)mm Hg,P＜0.05],与最大顺应性法相比差异无统计学意义(P＞0.05),均高于基础状态.最小死腔分数法选择PEEP机械通气时气道平台压[(24±4) cm H2O]明显低于最大氧合法[(31±9) cm H2O].最佳氧合法选择的PEEP机械通气时的FRC明显高于最小死腔分数法和最大顺应性法.结论 采用最小死腔分数法选择的最佳PEEP,可改善ARDS患者氧合和CLst,减少死腔通气、降低气道平台压,是床边选择最佳PEEP的可行方法.     

气体代谢运动试验指导心力衰竭病人康复治疗的效果

目的:探讨气体代谢运动试验对心衰病人康复治疗的指导价值。方法:选择纽约心脏病协会(NYHA)心功能Ⅱ～Ⅲ级病人77例进行气体代谢运动试验(气体代谢试验组),根据气体代谢运动试验结果制定康复方案,半年后复查,与既往进行常规康复治疗的NYHA心功能Ⅱ～Ⅲ级病人(常规康复组,65例)的疗效进行比较,比较两组病人心功能分级、运动时最大摄氧量(V.O2max),6min步行距离等参数。结果:与常规康复组比较,气体代谢试验组病人康复治疗半年后心功能分级无显著差异,而运动时V.O2max[(22.3±7.5)ml.kg-1.min-1比(26.5±5.9)ml.kg-1.min-1],6min步行距离[(315.2±25.5)m比(396.7±20.6)m]明显增加(P均<0.05)。结论:基于气体代谢运动试验结果制订的康复方案可以改善心衰病人运动功能,最大摄氧量,6min步行距离。     

气道正压通气治疗对CHF合并睡眠呼吸暂停患者最大摄氧量等的影响

目的:探讨经鼻持续气道正压通气治疗(nCPAP)对慢性充血性心力衰竭(CHF)合并中重度阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者最大摄氧量(V·O2max)的影响,探讨其意义。方法:选择CHF合并中重度OSAHS患者83例,随机分为常规治疗组(40例)及nCPAP治疗组(43例),治疗6个月,测定治疗前后左室射血分数、呼吸暂停低通气指数(AHI)及V·O2max值,比较两组差异。结果:治疗6月后,与常规治疗组比较,nCPAP治疗组AHI[(27.5±6.2)比(6.8±1.2)]显著降低,LVEF[(0.45±0.07)比(0.48±0.05)]及V·O2max值[(16.5±3.5)ml·kg-1·min-1比(19.2±3.4)ml·kg-1·min-1]显著升高(P均0.05)。结论:经鼻持续气道正压通气治疗可以改善已接受基础药物治疗的CHF合并中重度OSAHS患者通气功能、心功能和最大摄氧量。     

慢性阻塞性肺疾病患者生理死腔容积/潮气容积估测值与实测值的比较

生理死腔容积／潮气容积（VD／VT）是呼吸生理的一个重要参数，静态时增高或运动时不降低表明通气和血流不匹配，在临床上提示有原发性或继发性肺血管疾病等异常。临床上可通过有创和无创两种方法计算VD／VT，前者是抽取动脉血测定动脉血二氧化碳分压（PaCO2），计算实测VD／VT；后者是用呼气末二氧化碳分压（PETCO2）代替PaCO2估测VD／VT。我们观察了慢性阻塞性肺疾病（COPD）患者静态和运动状态下的VD／VT估测值与实测值的差别。     

Use of arm crank exercise in the detection of abnormal pulmonary gas exchange in patients at low altitude.

BACKGROUND: The measurement of arterial blood gases, P(A-a)O2 and VD/VT, during cycle ergometry is the "gold standard" for the assessment of pulmonary gas exchange. However, some patients are unable to perform cycle ergometry because of other medical problems. STUDY OBJECTIVE: To determine whether arm crank exercise could be used to reliably detect gas exchange abnormalities compared to cycle ergometry. PARTICIPANTS: Fifteen patients with a variety of pulmonary disorders, who were referred for exertional dyspnea. DESIGN: All patients performed maximal arm crank and cycle exercise. Arterial blood gases, VO2, VCO2, and VE were measured at rest and during exercise. RESULTS: Compared to peak cycle exercise (mean +/- SD), PaO2 (85 +/- 14 vs 75 +/- 13 mm Hg), SaO2 (94 +/- 2 vs 91 +/- 4 percent), VD/VT (0.21 +/- 0.07 vs 0.19 +/- 0.08), and pH (7.37 +/- 0.04 vs 7.34 +/- 0.03) were significantly higher during peak arm crank exercise. The P(A-a)O2 (18 +/- 13 vs 29 +/- 12 mm Hg) was narrower, and PaCO2 (29 +/- 3 vs 29 +/- 4 mm Hg) and PAO2 (104 +/- 4 vs 103 +/- 4 mm Hg) were similar. Six patients had normal gas exchange during cycle exercise at low altitude (P[A-a]O2 less than or equal to 27 mm Hg, PaO2 greater than or equal to 65 mm Hg, VD/VT less than or equal to 0.18) and nine were abnormal. Utilizing criteria specific for arm crank at low altitude, the same six patients had normal gas exchange (P[A-a]O2 less than or equal to 13 mm Hg, PaO2 greater than or equal to 85 mm Hg, VD/VT less than or equal to 0.26), and the remaining nine were abnormal. The P(A-a)O2 during peak arm crank was the most useful criterion in identifying patients with abnormal gas exchange. CONCLUSION: Proposed criteria for arm crank exercise testing accurately identified all patients with normal and abnormal pulmonary gas exchange during cycle exercise. The data from the present study suggest that arm crank can be an acceptable alternative exercise testing modality for the assessment of pulmonary gas exchange.     

肺移植对5例慢性阻塞性肺疾病患者肺功能的影响

目的研究单肺移植手术治疗慢性阻塞性肺疾病(COPD)对呼吸生理及肺功能的影响。方法5例患者均为Ⅳ级COPD男性患者,年龄51～63岁。术前2周测定患者用力肺活量(FVC)、第一秒用力呼气容积(FEV1)、FEV1/FVC、最大通气量(MVV)、残气容积(RV)、肺总量(TLC)、残总比(RV/TLC)、深吸气量(IC)、胸腔气体容积(TGV)、呼气峰流量(PEF)、总气道阻力(Rawtotal)、肺一氧化碳弥散量(DLCO)、每升肺泡容积肺一氧化碳弥散量(DLCO/V·A)、6分钟行走距离(6MWD)、动脉血氧分压(PaO2)、肺泡气动脉血氧分压差[P(Aa)O2]、动脉血氧饱和度(SaO2)、动脉血二氧化碳分压(PaCO2)及平均肺动脉压(mPAP)等参数。术后2个月再行上述测定。结果5例患者术前2周、术后2个月检测的参数为MVV(23.6±5.8)、(71.6±21.8)L,FEV1(0.68±0.21)、(1.85±0.46)L,FEV1/FVC(37.4±8.3)、(75.6±13.9)%,PaO2(60.0±9.1)、(86.2±2.9)mmHg(1mmHg=0.133kPa),SaO2(90.0±4.6)%、(96.8±0.5)%及mPAP(31.2±5.5)、(16.6±1.8)mmHg,均有显著改善(P均<0.05);3例患者IC[(1.16±0.26)、(1.83±0.35)L]、TGV[(6.52±0.27)、(4.52±0.29)L]、RV[(5.12±0.39)、(3.20±0.32)L]、RV/TLC[(71.0±5.6)、(51.3±2.5)%]及Rawtotal[(6.62±0.99)、(2.48±0.87)cmH2O·L-1·s-1]改善显著(P均<0.05);4例患者PEF[(1.65±0.40)、(3.92±1.63)L/s]、DLCO[(8.5±3.0)、(21.0±6.2)ml·min-1·mmHg-1]及6MWD[(46.8±14.7)、(246.8±51.9)m]也显著增加(P均<0.05);FVC[(1.85±0.40)、(2.45±0.49)L]、TLC[(7.19±0.15)、(6.26±0.73)L]、DLCO/V·A[(2.90±1.50)、(5.41±0.87)L·min-1·mmHg-1]、P(Aa)O2[(37.6±16.3)、(17.8±6.3)mmHg]及PaCO2[(44.6±7.7)、(37.4±3.4)mmHg]有所改善,但差异无统计学意义(P均>0.05)。结论COPD患者肺移植术后肺通气、气道阻力、残气、弥散、运动耐力及气体交换功能均明显改善。     

Gas exchange during maximal upper extremity exercise

STUDY OBJECTIVE: to characterize gas exchange and cardiopulmonary performance during maximal progressive arm crank exercise. DESIGN: Cardiopulmonary variables were measured and arterial blood gases were determined in blood samples obtained from an indwelling radial arterial catheter during arm crank exercise (34 watts/min). Arm crank exercise was compared to maximal leg exercise performed by a different but comparable group of subjects from a previous study. PARTICIPANTS: 19 healthy young (mean +/- SEM: 20 +/- 1 yr) black males. RESULTS: Peak arm crank exercise resulted in lower values compared to peak leg exercise for: power (129 +/- 2 vs 253 +/- 10 W), VO2 (2.17 +/- 0.04 vs 3.26 +/- 0.14 L/min); VCO2 (2.9 +/- 0.11 vs 4.32 +/- 0.17 L/min); HR (168 +/- 3 vs 189 +/- 3 beats/min); AT (1.15 +/- 0.05 vs 1.83 +/- 0.07 L/min); and VE (101 +/- 2 vs 144 +/- 8 L/min), respectively. Arm crank exercise (baseline vs peak) elicited an impressive improvement in PaO2 (85 +/- 1 to 97 +/- 1 mm Hg), no change in SaO2 (96 +/- 0.2 to 96 +/- 0.2 percent), no significant increase in P(A-a)O2 (3 +/- 0.7 to 5 +/- 0.9 mm Hg) and an appropriate trending decrease in VD/VT (0.22 +/- 0.01 to 0.17 +/- 0.01). Peak arm crank values were significantly different from peak cycle exercise for PaO2 (82 +/- 2.2 mm Hg), SaO2 (93 +/- 0.4 percent), P(A-a)O2 (21 +/- 1.9 mm Hg) and VD/VT (0.08 +/- 0.01). At comparable levels of VO2 for arm crank and cycle exercise (2.17 +/- 0.04 vs 2.26 +/- 0.08 L/min), significant differences were observed for PaO2 (97 +/- 1.4 vs 81 +/- 1.9 mm Hg); SaO2 (96 +/- 0.2 vs 94 +/- 0.4 percent); P(A-a)O2 (5 +/- 0.9 vs 14 +/- 1.5 mm Hg); and VD/VT (0.17 +/- 0.01 vs 0.08 +/- 0.01), respectively. CONCLUSIONS: Maximal arm crank exercise represents a submaximal cardiopulmonary stress compared to maximal leg exercise. The differences in gas exchange observed at peak exercise between arm crank and leg exercise for the most part reflect the lower VO2 achieved. However, the persistence of these gas exchange differences even at a comparable level of VO2 suggests that factors other than VO2 may be operative. These factors may include differences in alveolar ventilation, CO2 production, ventilation-perfusion inequality, diffusion, and control of breathing.     

分侧肺通气时不同呼气末正压和潮气量对单侧肺损伤犬循环的影响

目的 观察不同步分侧肺通气和同步分侧肺通气对单侧急性肺损伤(ALI)犬循环的影响.方法 取健康杂种犬12只,建立盐酸所致单侧肺损伤动物模型,行容积控制通气,将犬按随机数字表法分为不同步分侧肺通气组(NS组)和同步分侧肺通气组(S组).参数:患侧潮气量3.5 ml/kg保持不变,呼气末正压(PEEP)选择15、20、25 cm H2O(1 cm H2O=0.098 kPa);患侧PEEP 10 cm H2O不变,潮气量用随机数字表法选择5、7.5、10 ml/kg.健侧通气参数始终不变,检测不同通气条件下两组犬血流动力学和氧动力学指标.结果 (1)患侧潮气量3.5 ml/kg不变,PEEP为15、20 cm H2O时,两组血流动力学和氧动力学参数差异无统计学意义.当患侧PEEP为25 cm H2O时,NS组心率、体循环平均压(mABP)、心输出量、氧合指数和混合静脉血氧饱和度(SvO2)分别为(98±8)次/min、(84±6)mm Hg(1 mm Hg=0.133 kPa)、(1.10±0.13)L/min、(199±14)mm Hg和(55±6)%,明显低于S组[分别为(124±9)次/min、(103±7)mm Hg、(1.52±0.28)L/min、(221±15)mm Hg和(62±4)%,t值分别为-7.852、-16.561、-15.043、-13.314和-5.653,均P＜0.01].(2)患侧PEEP 10 cm H2O不变,潮气量分别为5、7.5 ml/kg时,两组的血流动力学和氧动力学参数比较差异无统计学意义.当患侧潮气量为10 ml/kg时,NS组HR、mABP、心输出量、氧合指数和SvO2均低于S组(均P＜0.01).结论 在本实验动物模型中,患侧与健侧所用PEEP水平相差≤20 cm H2O或患侧潮气量≤7.5 ml/kg时,同步和非同步分侧肺通气均能保持循环稳定.若需要更高水平PEEP时,建议选用同步分侧肺通气.     

慢性阻塞性肺疾病患者运动能力与其呼吸驱动及呼吸肌功能关系的研究

目的探究慢性阻塞性肺疾病（COPD）患者运动能力与呼吸驱动及呼吸肌功能之间的关系。方法对28例COPD患者和26名正常对照者分别检测静息常规肺功能、肺弥散功能（DLCO）、口腔阻断压（P0.1）、最大吸气压（PImax）及最大呼气压（PEmax）,并进行运动负荷试验观测氧耗量（VO2）、二氧化碳产生量（VCO2）、分钟通气量（E）、潮气量（T）等气体代谢指标,同时记录受试者运动中的呼吸困难指数（BorgScale）。运动负荷前、后检测动脉血气分析。结果（1）COPD组患者PImax（40±15）mmHg明显低于正常人组（53±19）mmHg（P<0.05）,PEmax在两组中差异无显著性（P>0.05）,COPD组患者P0.1（2.8±0.9）mmHg明显高于正常人组（2.0±0.7）mmHg（P<0.05）,P0.1/PImax（0.069±0.021）也明显高于正常人组（0.037±0.009）（P<0.01）。（2）COPD组患者VO2max与P0.1及PImax未发现明显的相关关系（P>0.05）,但与P0.1/PImax明显正相关（r=0.66,P<0.01）,BorgScale与P0.1/PImax明显正相关（r=0.49,P<0.05）。结论COPD患者运动能力下降除与气道阻塞程度及气体交换障碍等有关外,呼吸驱动相对增高及呼吸肌功能障碍也是其运动能力的限制因素。     

Transition from exercise to rest. Ventilatory and arterial blood gas responses

The mechanisms leading to rapid changes in arterial blood gas values soon after exercise ends have not been well established. To further study these phenomena, we exercised seven normal male volunteers to exhaustion on a cycle ergometer with a 25-W/min ramped protocol measuring arterial blood gas values, and breath-by-breath gas exchange from rest to exercise and through 15 minutes of recovery. Arterial PO2 (PaO2) increased from 108 mm Hg at peak exercise to 125 mm Hg at 2 minutes of recovery. There was a smaller rise in calculated alveolar PO2 (PAO2) from 121 to 128 mm Hg over the same period. Arterial PCO2 (PaCO2) fell from 35.0 mm Hg to 31.9 mm Hg. The gas exchange ratio R rose from 1.21 to 1.52, after having peaked at 1.68 at 1 minute. The alveolar-arterial O2 gradient (P[A-a]O2) fell from 12.3 mm Hg at peak exercise to 3.2 mm Hg at 2 minutes. Following exercise, the rise in R is related to a more rapid fall in O2 uptake than in CO2 output, and the fall in P(A-a)O2 is probably related to improved V/Q relationships and to a rise in mixed venous PO2. We conclude that the rise in PaO2 in the recovery period after progressive nonsteady state exercise is due to several factors, including a fall in P(A-a)O2 and a rise in PAO2 due primarily to an elevation of R and also to a fall in PaCO2.     

Significance of end-tidal P(CO(2)) response to exercise and its relation to functional capacity in patients with chronic heart failure

OBJECTIVES: The value of end-tidal PCO(2) monitoring during exercise in patients with chronic heart failure has not been elucidated. The present study was designed to examine end-tidal PCO(2) response to exercise and its relation to functional capacity in patients with chronic heart failure. METHODS AND RESULTS: Maximal upright ergometer exercise with respiratory gas analysis and arterial blood gas analysis were performed in 105 patients with chronic heart failure (34 patients in New York Heart Association [NYHA] class I, 38 patients in NYHA class II, and 33 patients in NYHA class III) and 14 normal control subjects. Peak O(2) uptake, excessive exercise ventilation as assessed by the slope of the relation between expired minute ventilation and CO(2) output (VE-VCO(2)), and the ratio of physiologic dead space to tidal volume (VD/VT) were determined. Cardiac output was also measured during exercise in 28 patients with chronic heart failure. Arterial PO(2) or PCO(2) values at rest and during exercise were not different among the four groups. However, end-tidal PCO(2) was significantly lower, and arterial to end-tidal PCO(2) difference and VD/VT were significantly higher in NYHA class III patients than other groups during exercise. The maximal end-tidal PCO(2) during exercise was significantly reduced as the severity of chronic heart failure advanced (45.7 +/- 4.0 mm Hg in normal control subjects, 43.5 +/- 4.8 mm Hg in NYHA class I patients, 39.7 +/- 5.1 mm Hg in NYHA class II patients, and 34.9 +/- 5.3 mm Hg in NYHA class III patients). The maximal end-tidal PCO(2) during exercise was significantly correlated with peak O(2) uptake (r = 0.68; p < 0.001) and maximal cardiac index (r = 0.73; p < 0.001), and inversely related to Ve-VCO(2) (r = - 0.84; p < 0.001) and VD/VT at peak exercise (r = -0.65; p < 0.001). CONCLUSIONS: The decreased end-tidal PCO(2) during exercise, which is caused by high ventilation/perfusion ratio mismatching, reflects both reduced cardiac output response to exercise and increased exercise ventilation due to enlarged physiologic dead space in advanced chronic heart failure. The end-tidal PCO(2) during exercise can be used to evaluate the functional capacity of patients with chronic heart failure.     

Airway insufflation: physiologic effects on acute and chronic gas exchange in humans

Reduction in dead space through conventional tracheostomy has been used to treat patients with chronic CO2 retention. The insufflation of air directly into the trachea by transtracheal catheter (airway insufflation, AI) provides reductions in dead space as great or greater than those of tracheostomy. The physiologic effects of AI on gas exchange have not been adequately studied because instillation of gases into the trachea contaminates minute ventilation (VL), dead space volume (VD), tidal volume (VT), and other indices of gas exchange, as measured by usual technics. We overcame this problem by devising special methods of measuring inspired and expired ventilation, alveolar and dead space ventilation, and VT and VD by using pneumotachographic timing of inspiration and expiration so that true inspired and expired ventilation were calculated. We studied 5 patients with chronic CO2 retention from either COPD, scoliosis, or muscular dystrophy (annual average PaCO2 = 45 to 75 mm Hg) during 75 min of AI with serial gas exchange and arterial blood gas measurements. AI at about 5 L/min of room air through the trachea in 5 patients reduced VL by 18% (from 7.91 to 6.48 L/min), VT by 25% (from 450 to 338 ml), and VD by 37% (from 223 to 141 ml), while not affecting PaCO2 (from 51.8 to 48.2 mm Hg) or PaO2 (from 65.1 to 63.4 mm Hg). In 2 patients, AI administered continuously for 4 to 12 months (as 30 to 50% O2) maintained PaCO2 as well as or better than breathing enriched O2 from a tracheal collar via an open tracheostomy.(ABSTRACT TRUNCATED AT 250 WORDS)     

外源性肺泡表面活性物质联合肺泡复张手法对急性呼吸窘迫综合征的疗效

目的 观察肺泡表面活性物质(PS)、肺泡复张手法(RM)及两者联合治疗ARDS的疗效.方法 健康新西兰长耳白兔28只,反复温盐水肺泡灌洗建立ARDS动物模型,行容积控制通气,通气稳定后按随机数字表法分为对照组、PS组、RM组及PS+RM组,每组7只,分别气管内注入安慰剂、外源性PS、实施RM或PS联合RM治疗,观察动脉血气及呼吸力学指标的变化.处理后4 h处死动物,行病理组织学检查评价肺损伤程度.结果 (1)对照组、PS组、RM组和PS+RM组的PaO2分别为(74 ±15)、(234±42)、(231±17)和(253±52)mm Hg(1 mm Hg=0.133 kPa),PS、RM和PS+RIM3组均高于对照组(F=84.201,P<0.01),PS、PS+RM组氧合改善稳定,RM组PaO2随观测时间延长呈下降趋势;(2)4组的PaCO2分别为(56±11)、(46±10)、(51±8)和(46±10)mm Hg,对照组明显高于PS、PS+RM组(F=4.234,P<0.05).RM组PaCO2随时间延长呈增高趋势;(3)4组动物气道峰压分别为(33±2)、(23±1)、(24±2)和(22±1)cm H2O(1 cm H2O=0.098 kPa),静态肺顺应性(Cst)分别为(1.1±0.3)、(1.7±0.3)、(1.5±0.1)、(1.9±0.4)ml/cm H2O,PS、RM、PS+RM 3组气道峰压、Cst均较对照组显著改善(F值分别为74.911、15.863,均P<0.01).RM组Cst改善较PS+RM组差(q=2.58,P<0.05);(4)PS、RM、PS+RM 3组动物肺损伤评分分别为3.9 ±0.8、6.1±0.7和4.2±0.6,均低于对照组的13.5±0.7(F=369.6,P<0.01),RM组高于PS及PS+RM组(q值分别为6.35、5.70,均P<0.01).结论 ARDS早期补充外源性PS或实施RM均能有效改善氧合及肺脏顺应性,但RM后易出现肺泡再萎陷及呼吸机相关性肺损伤;PS联合RM治疗能防止肺泡再萎陷,并可减轻呼吸机相关性肺损伤.