Warner D O
Mayo Medical School, Rochester, MN 55905.
Ann Acad Med Singap. 1994 Jul;23(4):566-71.
The effects of anaesthesia and surgery on the chest wall may be responsible for impaired gas exchange and other pulmonary complications during the perioperative period. Current evidence supports the following sequence of events. Anaesthesia changes the shape and motion of the chest wall, either by changing the amount of tonic and phasic activity of the respiratory muscles (anaesthesia with spontaneous breathing) or by eliminating the activity entirely (paralysis with mechanical ventilation). These primary changes in chest wall function lead to secondary changes in lung function, including the formation of dependent lung atelectasis. Recent advances in imaging of the thorax have called into question traditional understanding of the mechanisms by which anaesthesia alters chest wall function. For example, it is now apparent that anaesthesia reduces the functional residual capacity not by changing the position of the diaphragm, but rather by affecting the rib cage, and, perhaps, the volume of intrathoracic blood. The effects of anaesthesia and surgery on postoperative chest wall function may be lessened by regional analgesia and the use of laparoscopic surgical techniques. However, it is not yet clear that this improvement is associated with a reduction in the incidence of pulmonary complications.
麻醉和手术对胸壁的影响可能是围手术期气体交换受损和其他肺部并发症的原因。目前的证据支持以下一系列事件。麻醉通过改变呼吸肌的紧张性和相位性活动量（自主呼吸麻醉）或完全消除活动（机械通气麻痹）来改变胸壁的形状和运动。胸壁功能的这些原发性变化导致肺功能的继发性变化，包括依赖性肺不张的形成。胸部成像的最新进展对麻醉改变胸壁功能机制的传统理解提出了质疑。例如，现在很明显，麻醉降低功能残气量不是通过改变膈肌的位置，而是通过影响胸廓，也许还有胸腔内血液量。区域镇痛和使用腹腔镜手术技术可能会减轻麻醉和手术对术后胸壁功能的影响。然而，目前尚不清楚这种改善是否与肺部并发症发生率的降低有关。
