Wilson B A, Jackson P J, Evans J
Int J Sports Med. 1981 Feb;2(1):27-30. doi: 10.1055/s-2008-1034580.
Five volunteers, all with a history of childhood asthma that had persisted, though at a reduced severity and incidence, through their teens to the present, performed six treadmill runs on separate days for 6 min at 80% of VO2 max followed by 20 min of recovery. Two trials were completed under each of the following conditions: normal, positive end-expiratory pressure breathing (PEEP) during the work, and PEEP post-exercise. For each trial, forced vital capacity maneuvers (FVC) were completed twice at rest, at the 3rd and 6th min of exercise, and every 5 min during the 20-min recovery. No significant effects of PEEP in resting pulmonary function values was found nor was PET CO2 altered for rest, exercise, or recovery for PEEP vs normal trials. For the normal exercise tests, post-exercise broncho-constriction was shown by at 30% to 50% decrease in FEV1.0, 30% to 40% drop in PEF, and a 45% to 65% decrease in maximal flow at 50% VC (MEF50), comparing post-exercise values to rest. PEEP during and PEEP post conditions significantly (P less than 0.01) decreased the severity of exercise-induced asthma (EIA) as PEFR and FEV1.0 values remained within 20% of rest levels and MEF50 within 30%. Since PET CO2 was not altered by the PEEP conditions, the airway response cannot be mediated through CO2 effect, It is known that PEEP does reduce air trapping, but since PEEP during work had a lasting effect into recovery this indicates that some additional mechanism may be involved.
五名志愿者，他们都有儿童期哮喘病史，这种哮喘一直持续到青少年时期乃至现在，不过严重程度和发病率有所降低。他们在不同的日子里进行了六次跑步机跑步测试，以80%的最大摄氧量（VO2 max）跑6分钟，随后休息20分钟。在以下每种条件下完成了两项试验：正常状态、运动期间呼气末正压通气（PEEP）以及运动后PEEP。对于每次试验，在静息状态、运动第3分钟和第6分钟以及20分钟恢复期间每5分钟进行两次用力肺活量动作（FVC）。未发现PEEP对静息肺功能值有显著影响，并且在PEEP试验与正常试验的静息、运动或恢复过程中，呼气末二氧化碳分压（PET CO2）也未改变。对于正常运动测试，运动后支气管收缩表现为第一秒用力呼气量（FEV1.0）下降30%至50%、呼气峰值流速（PEF）下降30%至40%以及50%肺活量时的最大流速（MEF50）下降45%至65%，将运动后的值与静息值进行比较。运动期间和运动后PEEP条件显著（P小于0.01）降低了运动诱发哮喘（EIA）的严重程度，因为呼气峰值流速（PEFR）和FEV1.0值保持在静息水平的20%以内，MEF50保持在30%以内。由于PEEP条件未改变PET CO2，气道反应不能通过二氧化碳效应介导。已知PEEP确实会减少气体潴留，但由于运动期间的PEEP对恢复有持久影响，这表明可能涉及一些额外的机制。
