肺复张对病态肥胖患者容积式二氧化碳描记术III期斜率的影响。

The effects of lung recruitment on the Phase III slope of volumetric capnography in morbidly obese patients.

作者信息

Böhm Stephan H, Maisch Stefan, von Sandersleben Alexandra, Thamm Oliver, Passoni Isabel, Martinez Arca Jorge, Tusman Gerardo

机构信息

Clinic of Anesthesiology, University Hospital, Hamburg-Eppendorf, Hamburg, Germany.

出版信息

Anesth Analg. 2009 Jul;109(1):151-9. doi: 10.1213/ane.0b013e31819bcbb5.

DOI:10.1213/ane.0b013e31819bcbb5

PMID:19535705

Abstract

BACKGROUND

In this study, we analyzed the effect of the alveolar recruitment strategy (ARS) and positive end-expiratory pressure (PEEP) titration on Phase III slope (S(III)) of volumetric capnography (VC) in morbidly obese patients.

METHODS

Eleven anesthetized morbidly obese patients were studied. Lungs were ventilated with tidal volumes of 10 mL x kg(-1), respiratory rates of 12-14 bpm, inspiration:expiration ratio of 1:2, and FIO2 of 0.4. ARS was performed by increasing PEEP in steps of five from 0 end-expiratory pressure to 15 cm H2O. During lung recruitment, plateau pressure was limited to 50 cm H2O whereas tidal volume was increased to the ventilator's maximum value of 1400 mL, and PEEP was increased to 20 cm H2O for 2 min. Thereafter, PEEP was reduced in steps of 5 cm H2O, from 15 to 0. VC, arterial blood gases, and lung mechanics data were determined for each PEEP step.

RESULTS

S(III) decreased from 0.014 +/- 0.006 to 0.005 +/- 0.005 mm Hg/mL when 0 end-expiratory pressure was compared against 15 cm H2O of PEEP after ARS (15ARS, P < 0.05). This decrement in S(III) was accompanied by increases in PaO2 (27%, P < 0.002) and compliance (32%, P < 0.001), whereas PaCO2 decreased by 8% (P < 0.038) when comparing values before and after ARS. A good prediction of the lung recruitment effect by S(III) was derived from the receiver operating characteristic curve analysis (area under the curve of 0.81, sensitivity of 0.75, and specificity of 0.74; P < 0.001).

CONCLUSION

The S(III) in VC was useful to detect the optimal level of PEEP after lung recruitment in anesthetized morbidly obese patients.

摘要

背景

在本研究中，我们分析了肺泡复张策略（ARS）和呼气末正压（PEEP）滴定对病态肥胖患者容积式二氧化碳描记法（VC）第三相斜率（S(III)）的影响。

方法

对11例麻醉状态下的病态肥胖患者进行研究。采用潮气量10 mL×kg⁻¹、呼吸频率12 - 14次/分钟、吸呼比1:2以及吸入氧分数0.4进行肺通气。通过将呼气末压力从0逐步以5 cm H₂O的幅度增加到15 cm H₂O来实施ARS。在肺复张过程中，平台压限制在50 cm H₂O，而潮气量增加到呼吸机的最大值1400 mL，并且PEEP增加到20 cm H₂O并维持2分钟。此后，PEEP以5 cm H₂O的幅度从15 cm H₂O降至0。对每个PEEP水平测定VC、动脉血气和肺力学数据。

结果

在ARS后，将呼气末压力0与15 cm H₂O的PEEP进行比较时，S(III)从0.014±0.006降至0.005±0.005 mmHg/mL（15ARS，P < 0.05）。S(III)的这种下降伴随着动脉血氧分压（PaO₂）升高27%（P < 0.002）和顺应性升高32%（P < 0.001），而比较ARS前后的值时，动脉血二氧化碳分压（PaCO₂）下降了8%（P < 0.038）。通过受试者工作特征曲线分析得出S(III)对肺复张效果有良好的预测能力（曲线下面积为0.81，敏感性为0.75，特异性为0.74；P < 0.001）。