Hinkelbein Jochen, Genzwuerker Harald V, Fiedler Fritz
Institute of Anaesthesiology and Intensive Care Medicine, Faculty of Clinical Medicine Mannheim, Ruprecht-Karls-University Heidelberg, University Hospital Mannheim, Mannheim, Germany.
Resuscitation. 2005 Mar;64(3):315-9. doi: 10.1016/j.resuscitation.2004.10.006.
To determine the error of measurement in pulse oximetry with a decreased arterial perfusion and to identify a systolic pressure threshold for (1) initial detection and (2) a reliable reading of oxygen saturation.
An experimental clinical prospective study. The study was approved by the local ethics committee.
Eighteen bed intensive care unit at a University hospital.
Twenty-five adult mechanically ventilated and critically ill patients in the ICU during a 3-month period.
A blood pressure cuff at the upper arm (same side as an arterial catheter already in place) was inflated to decrease the arterial pulsatile flow. The cuff was deflated stepwise and the resulting oxygen saturation was measured simultaneously. The error of measurement [delta S = SpO2 (baseline)-SpO2 (indicated)] was calculated for each 5 mmHg of blood pressure (BP).
Twenty-five patients (9 female, 16 male, 48 +/- 15.9 years old) with a mean SpO2 of 98.3 +/- 1.5% and a BP of 129 +/- 18.4 mmHg participated. The mean systolic BP to obtain initial readings with pulse oximetry was 45.8 +/- 17.7 (range, 25-101) mmHg (35% of the baseline pressure) resulting in lower readings of pulse oximetry (mean -11.5 +/- 13.6%, range -45 to +4%). With a systolic BP > 80 mmHg the mean bias was within the manufacturers limits of +/-2%.
Pulse oximetry is reliable with a systolic blood pressure > 80 mmHg. The lower the BP, the lower the pulse oximetry readings leading to a bias of up to -45%.
确定动脉灌注减少时脉搏血氧饱和度测量的误差，并确定（1）初始检测和（2）可靠的血氧饱和度读数的收缩压阈值。
一项实验性临床前瞻性研究。该研究经当地伦理委员会批准。
一所大学医院的18张床位的重症监护病房。
在3个月期间，25名成年机械通气的重症监护病房患者。
在上臂（与已有的动脉导管同侧）使用血压袖带充气以减少动脉搏动血流。袖带逐步放气，同时测量所得的血氧饱和度。每5 mmHg血压（BP）计算测量误差[δS = SpO2（基线）-SpO2（显示值）]。
25名患者（9名女性，16名男性，48±15.9岁）参与，平均SpO2为98.3±1.5%，血压为129±18.4 mmHg。使用脉搏血氧饱和度仪获得初始读数的平均收缩压为45.8±17.7（范围25 - 101）mmHg（基线压力的35%），导致脉搏血氧饱和度仪读数较低（平均-11.5±13.6%，范围-45至+4%）。收缩压>80 mmHg时，平均偏差在制造商规定的±2%范围内。
收缩压>80 mmHg时，脉搏血氧饱和度测量可靠。血压越低，脉搏血氧饱和度仪读数越低，偏差可达-45%。
