Koivusalo A, Kauppinen H, Anttila A, Heikkilä P, Rintala R, Lindahl H
Helsinki University Hospital for Children and Adolescents, Finland.
J Pediatr Surg. 2000 Oct;35(10):1462-7. doi: 10.1053/jpsu.2000.16415.
BACKGROUND/PURPOSE: Gastric or rectosigmoid intramural pH (pHi) is considered a reliable indicator of splanchnic perfusion. The aim of this study was to evaluate whether rectosigmoid pHi reflects the severity of bowel damage in experimental necrotizing enterocolitis (NEC).
A total of 36 neonatal piglets, (median age, 3; range, 1 to 11 days; median weight, 2.5; range, 1.2 to 3.8 kg), were anesthetized, ventilated mechanically, and had invasive monitoring of hemodynamics. A sigmoid tonometer was inserted into the rectosigmoid colon. Enterocolitis was induced in 27 piglets by intraluminal injection of casein-d-gluconate (16.0 mL/kg) into terminal 100 cm of the ileum. Nine control piglets received an equal amount of intraluminal saline. NEC was graded macroscopically as follows: 0, no changes; 1, mild; 2, moderate; and 3, severe. Histology was evaluated according to Chiu scale from 0 to 5.
The macroscopical bowel injury in caseine-injected piglets was as follows: grade 3 (n = 6), grade 2 (n = 9), grade 1 (n = 12). All control piglets showed macroscopically normal bowel (grade 0). All affected bowels showed histologic changes (Chiu's scale 2 to 4). All study animals had an initial drop of pHi after injection of casein or saline. In control piglets and those with mild NEC (grade 1) pHi tended to return to preinjection level. In animals with moderate or severe NEC (grade 2 to 3) the initial drop was deeper and the pHi continued to decrease significantly throughout the experiment (P < .05). In the arterial pH and mean blood pressure there were no statistically significant differences between piglets with no NEC and mild NEC, and these with moderate or severe NEC.
Drop in rectosigmoid pHi was the most sensitive and earliest sign of severe mucosal necrosis of ileum in this experimental NEC model.
背景/目的：胃或直肠乙状结肠壁内pH值（pHi）被认为是内脏灌注的可靠指标。本研究的目的是评估直肠乙状结肠pHi是否能反映实验性坏死性小肠结肠炎（NEC）中肠损伤的严重程度。
总共36只新生仔猪（中位年龄3天；范围1至11天；中位体重2.5千克；范围1.2至3.8千克），进行麻醉、机械通气，并对血流动力学进行有创监测。将乙状结肠张力计插入直肠乙状结肠。通过向27只仔猪回肠末端100厘米腔内注射酪蛋白 - d - 葡萄糖酸盐（16.0毫升/千克）诱导小肠结肠炎。9只对照仔猪接受等量的腔内生理盐水。NEC的宏观分级如下：0级，无变化；1级，轻度；2级，中度；3级，重度。组织学根据Chiu评分从0到5进行评估。
注射酪蛋白的仔猪的宏观肠损伤如下：3级（n = 6），2级（n = 9），1级（n = 12）。所有对照仔猪的肠道宏观正常（0级）。所有受影响的肠道均显示组织学变化（Chiu评分2至4）。所有研究动物在注射酪蛋白或生理盐水后pHi均出现初始下降。在对照仔猪和轻度NEC（1级）的仔猪中，pHi倾向于恢复到注射前水平。在中度或重度NEC（2至3级）的动物中，初始下降更深，并且在整个实验过程中pHi持续显著下降（P <.05）。在无NEC和轻度NEC的仔猪与中度或重度NEC的仔猪之间，动脉pH值和平均血压无统计学显著差异。
在这个实验性NEC模型中，直肠乙状结肠pHi下降是回肠严重黏膜坏死最敏感和最早的迹象。
