Tobin M J
Division of Pulmonary and Critical Care Medicine, Edward Hines Jr Veterans Administration Hospital, Loyola University of Chicago Stritch School of Medicine, Illinois.
Crit Care Clin. 1990 Jul;6(3):679-709.
Continuous monitoring of important respiratory indices has the potential for predicting catastrophes and for providing an opportunity for the timely institution of lifesaving measures. Pulmonary gas exchange can be assessed by indices derived from arterial blood gas measurements, but these are limited by their invasive and intermittent nature. Intra-arterial electrodes that provide a continuous recording of blood gases are under development and appear very promising. Specially designed pulmonary artery catheters permit continuous recording of mixed venous O2 saturation, whereas continuous, non-invasive recordings of arterial oxygenation can be obtained with pulse oximetry and transcutaneous electrodes. A satisfactory method of monitoring CO2 tension does not exist. Measurements of respiratory drive can be obtained at the bedside, but their clinical usefulness remains unknown. Assessment of respiratory muscle strength is helpful in determining the need for mechanical ventilation, but a practical method of diagnosing respiratory muscle fatigue remains elusive. Recordings of the airway pressure waveform, calculation of thoracic compliance, and detailed examination of the pattern of breathing are helpful in assessing pulmonary mechanics. Although respiratory monitoring provides much useful information, it does not substitute for careful bedside examination.
持续监测重要的呼吸指标有可能预测灾难，并为及时采取救生措施提供机会。肺气体交换可以通过动脉血气测量得出的指标进行评估，但这些指标受其侵入性和间歇性的限制。能够连续记录血气的动脉内电极正在研发中，且前景十分广阔。专门设计的肺动脉导管可连续记录混合静脉血氧饱和度，而通过脉搏血氧饱和度仪和经皮电极可获得动脉氧合的连续无创记录。目前尚无令人满意的监测二氧化碳分压的方法。呼吸驱动力的测量可在床边进行，但它们的临床实用性尚不清楚。评估呼吸肌力量有助于确定是否需要机械通气，但诊断呼吸肌疲劳的实用方法仍然难以捉摸。气道压力波形记录、胸廓顺应性计算以及呼吸模式的详细检查有助于评估肺力学。尽管呼吸监测提供了许多有用信息，但它不能替代仔细的床边检查。
