Critchlow J F
Department of Surgery, Harvard Medical School, Boston, Massachusetts.
Am J Med. 1987 Dec 18;83(6A):23-8. doi: 10.1016/0002-9343(87)90807-2.
Stress-related mucosal damage is related to a high intraluminal hydrogen ion concentration, a low intramural pH value, and a breakdown of the gastric mucosal barrier. Because the presence of gastric acid is required for stress-related mucosal damage to occur, therapy aimed at increasing intraluminal pH values has often been used as prophylaxis against complications. The amount of acid suppression required for adequate prophylaxis of gastrointestinal bleeding from stress-related mucosal damage has not been determined, but many investigators use a target gastric pH level of 3.5 to 4.0. When intravenous histamine (H2)-receptor antagonists are given in bolus dosing regimens to critically ill patients, fluctuations in gastric pH values are often observed, as might be expected. However, recent studies with primed continuous infusion of cimetidine in critically ill patients have demonstrated that consistent elevation of gastric pH to 4.0 may be attained with this regimen. Studies with continuous infusions of ranitidine are less conclusive; little information is available on famotidine.
应激相关黏膜损伤与管腔内氢离子浓度升高、壁内pH值降低以及胃黏膜屏障破坏有关。由于应激相关黏膜损伤的发生需要胃酸的存在，旨在提高管腔内pH值的治疗方法常被用作预防并发症的措施。预防应激相关黏膜损伤导致的胃肠道出血所需的抑酸量尚未确定，但许多研究人员将胃pH目标水平设定为3.5至4.0。当对重症患者采用静脉推注组胺（H2）受体拮抗剂给药方案时，正如预期的那样，常观察到胃pH值的波动。然而，最近对重症患者采用西咪替丁负荷持续输注的研究表明，该方案可使胃pH值持续升高至4.0。雷尼替丁持续输注的研究结果不太明确；关于法莫替丁的信息较少。
