Schnoor Joerg, Zoremba Norbert, Korinth Marcus C, Kochs Bjoern, Silny Jiri, Rossaint Rolf
Department of Anaesthesiology, University Hospital Aachen, Germany.
BMC Emerg Med. 2006 Jan 25;6:1. doi: 10.1186/1471-227X-6-1.
Patients with traumatic brain injuries and raised intracranial pressure (ICP) display biphasic response with faster gastric emptying during the early stage followed by a prolonged gastric transit time later. While duodenal contractile activity plays a pivotal role in transpyloric transit we investigated the effects of raised intracranial pressure on duodenal motility during the early phase. In order to exclude significant deterioration of mucosal blood supply which might also influence duodenal motility, luminal microdialysis was used in conjunction.
During general anaesthesia, 11 pigs (32-37 kg, German Landrace) were instrumented with both a luminal catheter for impedancometry and a luminal catheter for microdialysis into the proximal duodenum. Additionally, a catheter was inserted into the left ventricle to increase the intracranial pressure from baseline up to 50 mmHg in steps of 10 mmHg each hour by injection of artificial cerebrospinal fluid. At the same time, duodenal motility was recorded continuously. Duodenal luminal lactate, pyruvate, and glucose concentrations were measured during physiological state and during elevated intracranial pressure of 10, 20, 30, 40, and 50 mmHg in six pigs. Five pigs served as controls.
Although there was a trend towards shortened migrating motor cycle (MMC) length in pigs with raised ICP, the interdigestive phase I-III and the MMC cycle length were comparable in the groups. Spontaneous MMC cycles were not disrupted during intracranial hypertension. The mean concentration of lactate and glucose was comparable in the groups, while the concentration of pyruvate was partially higher in the study group than in the controls (p < 0.05). This was associated with a decrease in lactate to pyruvate ratio (p < 0.05).
The present study suggests that a stepwise and hourly increase of the intracranial pressure of up to 50 mmHg, does not influence duodenal motility activity in a significant manner. A considerable deterioration of the duodenal mucosal blood flow was excluded by determining the lactate to pyruvate ratio.
创伤性脑损伤且颅内压（ICP）升高的患者表现出双相反应，早期胃排空加快，随后胃传输时间延长。虽然十二指肠收缩活动在经幽门传输中起关键作用，但我们研究了早期颅内压升高对十二指肠运动的影响。为了排除可能影响十二指肠运动的黏膜血供显著恶化，同时使用了腔内微透析。
在全身麻醉期间，11头猪（32 - 37千克，德国长白猪）在十二指肠近端分别置入用于阻抗测定的腔内导管和用于微透析的腔内导管。此外，插入一根导管至左心室，通过注射人工脑脊液，使颅内压从基线逐步每小时升高10 mmHg，直至50 mmHg。同时，持续记录十二指肠运动。在6头猪的生理状态以及颅内压分别为10、20、30、40和50 mmHg升高状态下，测量十二指肠腔内乳酸、丙酮酸和葡萄糖浓度。5头猪作为对照。
虽然颅内压升高的猪的移行运动复合波（MMC）长度有缩短趋势，但两组的消化间期I - III期和MMC周期长度相当。颅内高压期间，自发MMC周期未被打乱。两组乳酸和葡萄糖的平均浓度相当，而研究组丙酮酸浓度部分高于对照组（p < 0.05）。这与乳酸/丙酮酸比值降低相关（p < 0.05）。
本研究表明，颅内压每小时逐步升高至50 mmHg，不会显著影响十二指肠运动活性。通过测定乳酸/丙酮酸比值排除了十二指肠黏膜血流的显著恶化。
