Brown K, Aun C, Jackson E, Mackersie A, Hatch D, Stocks J
Dept of Anaesthesia, Montreal Children's Hospital, Canada.
Eur Respir J. 1998 Oct;12(4):935-43. doi: 10.1183/09031936.98.12040935.
The aim of this study was to compare tidal volume (VT) derived from the Qualitative Diagnostic Calibration (QDC) method (VT,QDC) with measurements from pneumotachography (VT,PN,T) in anaesthetized infants. Measurements were made during spontaneous (SV) and intermittent positive pressure (IPPV) ventilation, sighs and airway occlusions. The VT,DIF was the difference between VT,QDC and VT,PNT (%VT). The contribution of the ribcage (rc) to VT,QDC (%rc) and the thoracoabdominal phase lag were also derived. Twenty-eight infants, mean (SD) age 14.0 (6.2) months were studied. VT,QDC represented VT,PNT most closely when > or = 20 breaths were analysed. There was close agreement during SV immediately after the calibration period (95% limits of agreement (LA; QDC - PNT) -23, 3.0%). The 95% LA increased to -9.6, 10.2% after 10 min. Accuracy diminished during IPPV (95% LA -38, 31%), and sighs. During airway occlusions, when VT,PNT was zero, the 95% LA were -63, 4.1 mL x kg(-1). Mean phase lag was 36 and 2%, respectively, during SV and IPPV (p<0.05). The %rc appeared to be overestimated, being in excess of 50% in infants under 12 months. The Qualitative Diagnostic Calibration method used to estimate tidal volume in anaesthetized infants was limited by the need to analyse > or = 20 breaths and by a loss of within-subject accuracy if measurement conditions or pattern of breathing changed.
本研究旨在比较定性诊断校准（QDC）方法得出的潮气量（VT，QDC）与麻醉婴儿中呼吸流速仪测量值（VT，PN，T）。测量在自主呼吸（SV）、间歇正压通气（IPPV）、叹息和气道阻塞期间进行。VT，DIF是VT，QDC与VT，PNT之间的差值（%VT）。还得出了胸廓（rc）对VT，QDC的贡献（%rc）以及胸腹相位滞后。研究了28名婴儿，平均（标准差）年龄为14.0（6.2）个月。当分析≥20次呼吸时，VT，QDC最接近VT，PNT。在校准期后立即进行的自主呼吸期间一致性良好（95%一致性界限（LA；QDC - PNT）为 -23，3.0%）。10分钟后95% LA增加到 -9.6，10.2%。在IPPV期间（95% LA -38，31%）和叹息时准确性降低。在气道阻塞期间，当VT，PNT为零时，95% LA为 -63，4.1 mL×kg-1。自主呼吸和IPPV期间平均相位滞后分别为36和2%（p<0.05）。%rc似乎被高估，12个月以下婴儿中超过50%。用于估计麻醉婴儿潮气量的定性诊断校准方法受到需要分析≥20次呼吸以及如果测量条件或呼吸模式改变则受试者内准确性丧失的限制。
