肥胖症患者在减肥手术前后的通气/灌注分布异常

Ventilation/Perfusion distribution abnormalities in morbidly obese subjects before and after bariatric surgery.

作者信息

Rivas Eva, Arismendi Ebymar, Agustí Alvar, Sanchez Marcelo, Delgado Salvadora, Gistau Concepción, Wagner Peter D, Rodriguez-Roisin Roberto

机构信息

Servei d'Anestesiologia, University of California, San Diego (UCSD), San Diego, CA; Institut d'investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Fundació Clínic per a la Recerca Biomédica (FCRB), University of California, San Diego (UCSD), San Diego, CA.

Institut d'investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Fundació Clínic per a la Recerca Biomédica (FCRB), University of California, San Diego (UCSD), San Diego, CA; CIBER Enfermedades Respiratorias (CIBERES), University of California, San Diego (UCSD), San Diego, CA.

出版信息

Chest. 2015 Apr;147(4):1127-1134. doi: 10.1378/chest.14-1749.

DOI:10.1378/chest.14-1749

PMID:25317652

Abstract

BACKGROUND

Obesity is a global and growing public health problem. Bariatric surgery (BS) is indicated in patients with morbid obesity. To our knowledge, the effects of morbid obesity and BS on ventilation/perfusion (V.a/Q.) ratio distributions using the multiple inert gas elimination technique have never before been explored.

METHODS

We compared respiratory and inert gas (V.a/Q. ratio distributions) pulmonary gas exchange, breathing both ambient air and 100% oxygen, in 19 morbidly obese women (BMI, 45 kg/m2), both before and 1 year after BS, and in eight normal-weight, never smoker, age-matched, healthy women.

RESULTS

Before BS, morbidly obese individuals had reduced arterial Po2 (76 ± 2 mm Hg) and an increased alveolar-arterial Po2 difference (27 ± 2 mm Hg) caused by small amounts of shunt (4.3% ± 1.1% of cardiac output), along with abnormally broadly unimodal blood flow dispersion (0.83 ± 0.06). During 100% oxygen breathing, shunt increased twofold in parallel with a reduction of blood flow to low V.a/Q. units, suggesting the development of reabsorption atelectasis without reversion of hypoxic pulmonary vasoconstriction. After BS, body weight was reduced significantly (BMI, 31 kg/m2), and pulmonary gas exchange abnormalities were decreased.

CONCLUSIONS

Morbid obesity is associated with mild to moderate shunt and V.a/Q. imbalance. These abnormalities are reduced after BS.

摘要

背景

肥胖是一个全球性且日益严重的公共卫生问题。减重手术适用于病态肥胖患者。据我们所知，从未有人使用多惰性气体消除技术探讨过病态肥胖和减重手术对通气/灌注（V.a/Q.）比值分布的影响。

方法

我们比较了19名病态肥胖女性（BMI为45 kg/m²）在减重手术前和术后1年以及8名体重正常、从不吸烟、年龄匹配的健康女性在呼吸空气和100%氧气时的呼吸和惰性气体（V.a/Q.比值分布）肺气体交换情况。

结果

在减重手术前，病态肥胖个体的动脉血氧分压降低（76±2 mmHg），肺泡 - 动脉血氧分压差增加（27±2 mmHg），这是由少量分流（心输出量的4.3%±1.1%）引起的，同时血流分散异常广泛呈单峰分布（0.83±0.06）。在呼吸100%氧气时，分流增加了两倍，同时流向低V.a/Q.单位的血流减少，提示出现了吸收性肺不张且低氧性肺血管收缩未逆转。减重手术后，体重显著降低（BMI为31 kg/m²），肺气体交换异常情况减少。