Auler J O, Saldiva P H, Martins M A, Carvalho C R, Negri E M, Hoelz C, Zin W A
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, Brazil.
Crit Care Med. 1990 Oct;18(10):1080-6. doi: 10.1097/00003246-199010000-00006.
Seven control subjects and seven patients with adult respiratory distress syndrome (ARDS) were artificially ventilated and flow, volume, and tracheal pressure were monitored. Respiratory system resistance (Rrs,max) was partitioned into its homogeneous (Rrs,min) and uneven (Rrs,u) components. Respiratory system elastance (Ers) was also measured. In both groups Ers did not vary with different inspiratory flows and volumes, but was significantly higher in ARDS. With increasing volume (isoflow maneuvers), Rrs,max and Rrs,u increased but Rrs,min remained unaltered in ARDS. In control patients, however, resistances did not vary but Rrs,max and Rrs,u were smaller and Rrs,min equaled their corresponding values in ARDS. Hence, stress relaxation seems to be increased in ARDS. During isovolume maneuvers Rrs,max and Rrs,u decreased with increasing flows (both groups), although they were significantly higher in ARDS. Rrs,min was not modified by different flows and was similar in both groups. Thus, pendelluft is also increased in ARDS. In conclusion, the mechanical profile of ARDS is characterized by increased Ers and Rrs,max, the latter being secondary to augmented mechanical unevenness within the system.
对7名对照受试者和7名成人呼吸窘迫综合征（ARDS）患者进行人工通气，并监测气流、容积和气管压力。将呼吸系统阻力（Rrs,max）分为均匀成分（Rrs,min）和不均匀成分（Rrs,u）。同时测量呼吸系统弹性（Ers）。两组中，Ers均不随吸气气流和容积的不同而变化，但在ARDS组中显著更高。在ARDS组中，随着容积增加（等流量操作），Rrs,max和Rrs,u增加，但Rrs,min保持不变。然而，在对照患者中，阻力无变化，但Rrs,max和Rrs,u较小，且Rrs,min等于ARDS组中的相应值。因此，ARDS患者的应力松弛似乎增强。在等容积操作期间，Rrs,max和Rrs,u随气流增加而降低（两组均如此），尽管在ARDS组中显著更高。Rrs,min不受气流不同的影响，且在两组中相似。因此，ARDS患者的摆动气也增加。总之，ARDS的力学特征是Ers和Rrs,max增加，后者是由于系统内力学不均匀性增加所致。
