Rudlof B, Faldum A, Brandt L
Zentralinstitut für Anästhesie, Klinikverbund St. Antonius und St. Josef, Wuppertal, Wuppertal, Deutschland.
Anaesthesist. 2010 May;59(5):401-9. doi: 10.1007/s00101-010-1711-0.
Aventilatory mass flow (AVMF) is routinely used for apneic oxygenation in various clinical procedures but no data exist to quantitatively describe the gas flow. This study was designed to determine the amount of AVMF during the clinical situation of apnea to force spontaneous respiration at the end of anaesthesia with controlled ventilation.
A total of 200 patients undergoing anesthesia for routine surgery were examined. AVMF was analyzed with a high resolution, low gas stream, thermal mass flow analyzer. The intended recording time was 3 min.
Measurement was reliably successful and suitable for evaluation in only 23 patients. AVMF-induced gas flow started on average 17.9 + or - 9.4 s after onset of apnea. Maximum flow was reached within 158 + or - 20 s and determined to be 135 + or - 32 ml/min. The slope of increase of gas flow showed a rapid oscillation corresponding to the heart rate in all patients and in 14 out of 23 patients a slow oscillation with a frequency of 8.9 + or - 1.8/min.
During apnea AVMF develops in a non-linear fashion. The maximum flow observed is closely related to the estimated oxygen consumption. Heart rate synchronous flow variations are probably caused by intrathoracic volume variations due to heart action. The low frequency oscillations correspond to the frequency of Traube-Hering-Mayer waves.
在各种临床操作中，通气质量流量（AVMF）通常用于无呼吸氧合，但尚无数据定量描述气体流量。本研究旨在确定在麻醉结束时控制通气的情况下，无呼吸时促使自主呼吸的AVMF量。
共检查了200例行常规手术麻醉的患者。使用高分辨率、低气流热质量流量分析仪分析AVMF。预期记录时间为3分钟。
仅在23例患者中测量可靠成功且适合评估。AVMF诱导的气流平均在呼吸暂停开始后17.9±9.4秒开始。在158±20秒内达到最大流量，确定为135±32毫升/分钟。所有患者气流增加斜率均显示与心率相对应的快速振荡，23例患者中有14例出现频率为每分钟8.9±1.8次的缓慢振荡。
呼吸暂停期间，AVMF呈非线性发展。观察到的最大流量与估计的氧耗密切相关。心率同步的流量变化可能是由于心脏活动引起的胸腔容积变化所致。低频振荡与特劳贝-黑林-迈尔波频率相对应。
