Shay S S, Conwell D L, Mehindru V, Hertz B
Department of Medicine, Walter Reed Army Medical Center, Washington DC, USA.
Am J Gastroenterol. 1996 Jan;91(1):54-60.
To examine the influence of three postures (upright and left and right recumbent) on gastroesophageal reflux event (RE) frequency and composition and a possible mechanism for the observations.
A) Forty fasting patients with (E+, n = 20) and without (E-, n =20) esophagitis were studied. Simultaneous manometry and pH monitoring were conducted in the left and right recumbent (10 min each) as well as the upright posture (20 min). RE were classified by the pH probe and/or the manometry catheter as acid or gas RE. B) In 23 patients referred for UGI series, radiographs were taken in the left and right recumbent and upright postures after barium and Fizzies.
A) Upright RE were similar in frequency in E+ and E- patients (2.6 +/- 0.5 vs 3.05 +/- 0.6). However, E+ patients had more recumbent RE (16.3 +/- 3 vs 0.65 +/- 0.2, p = 0.0001) than E- patients; moreover, the left recumbent posture had more recumbent RE than the right (10.9 +/- 2 vs 5.3 +/- 1, p < 0.02). Moving from recumbent to the upright posture had an opposite effect on RE in the two groups; RE decreased sixfold in E+ patients (16.3 +/- 3 vs 2.6 +/- 0.5, p = 0.0001) but increased fourfold in E- patients (0.65 +/- 0.2 vs 3.05 +/- 0.6, p = 0.0001). In examining RE composition in the E+ patients, RE were twofold more likely to be gas in the left recumbent posture (7.6 +/- 2 vs 3.3 +/- 1, p < 0.1); in direct contrast, RE were eightfold more likely to be acid in the right recumbent posture (4.7 +/- 1 vs 0.6 +/- 0.5, p = 0.0001). As expected from this observation, acid exposure was greater in the right than left posture (52 +/- 8 vs 15 +/- 6%, p < 0.0001). Although RE were too infrequent in E- patients to reach statistical significance, the effect of posture on the composition of the few RE that did occur mirrored that of the E+ patients. B) In 17/23 (74%) radiographs in the right recumbent posture, the EG junction was submerged in a barium pool below the air-barium interface in the stomach. In contrast, this occurred in 0/23 patients in the left recumbent and 1/23 patients in the upright postures because the EG junction was in the air above the barium pool.
Posture has an influence on RE frequency and composition while fasting, and the latter is likely due to whether the EG junction is submerged below liquid gastric contents or in the air above the liquid gastric contents.
研究三种体位（直立位以及左侧卧位和右侧卧位）对胃食管反流事件（RE）频率及构成的影响，并探讨观察结果可能的机制。
A）对40例空腹患者进行研究，其中20例有食管炎（E+组，n = 20），20例无食管炎（E-组，n = 20）。在左侧卧位和右侧卧位（各10分钟）以及直立位（20分钟）同时进行测压和pH监测。通过pH探头和/或测压导管将RE分为酸性反流或气体反流。B）对23例因上消化道造影检查前来就诊的患者，在服用钡剂和汽水后，分别在左侧卧位、右侧卧位和直立位拍摄X光片。
A）E+组和E-组患者直立位时的RE频率相似（2.6±0.5对3.05±0.�）。然而，E+组患者卧位时的RE比E-组更多（16.3±3对0.65±0.2，p = 0.0001）；此外，左侧卧位时的卧位RE比右侧卧位更多（10.9±2对5.3±1，p < 0.02）。从卧位转为直立位对两组患者的RE产生相反影响；E+组患者的RE减少了六倍（16.3±3对2.6±0.5，p = 0.0001），而E-组患者的RE增加了四倍（0.65±0.2对3.05±0.6，p = 0.0001）。在检查E+组患者的RE构成时，左侧卧位时RE为气体的可能性增加两倍（7.6±2对3.3±1，p < 0.1）；相反，右侧卧位时RE为酸性的可能性增加八倍（4.7±1对0.6±0.5，p = 0.0001）。根据这一观察结果，预期右侧卧位时的酸暴露比左侧卧位更大（5 ̇±8对15±6%，p < 0.0001）。尽管E-组患者的RE太少，未达到统计学意义，但体位对少数发生的RE构成的影响与E+组患者相似。B）在23例患者中，17例（74%）右侧卧位X光片显示食管胃交界处淹没在胃内气钡界面下方的钡剂池中。相比之下，左侧卧位时23例患者中无此情况，直立位时23例患者中有1例出现此情况，因为食管胃交界处位于钡剂池上方的气体中。
禁食时体位对RE频率及构成有影响，后者可能是由于食管胃交界处是淹没在胃内液体内容物下方还是在胃内液体内容物上方的气体中。
