5 In contrast Wang et al. found that a higher BMI predicted absence of symptoms.6 Men and older patients have been thought to have a higher pain threshold12,13 but clearly we need to understand the pathogenesis of symptoms in GERD better. The classical explanation of evocation of heartburn is that it is caused by the contact of acid on the nerve endings in the lower esophagus.

Patients with erosive reflux esophagitis would then intuitively experience more pain than those with non-erosive reflux disease (NERD). This, however, has not been the case and NERD patients may in fact experience more severe symptoms than those with erosive disease.14 It is clear therefore that apart from the degree of acid exposure, various other putative see more mechanisms

are plausible. Esophageal mucosal sensitivity, prolonged or abnormal esophageal contraction and psychological factors have all been shown to play a role.15–17 The role of esophageal sensitivity in the pathogenesis of symptoms is intriguing. In a recent study from our group, we identified a group of patients with asymptomatic esophagitis who did not report “heartburn” with acid perfusion, which we labeled as having a “hyposensitive” esophagus.18 What are the clinical implications of silent GERD? The highest prevalence of asymptomatic GERD is in patients with extra-esophageal manifestations of GERD. In patients with refractory asthma and chronic cough associated with GERD, it buy MK-2206 has been noted that 25–75% do not have classical symptoms of GERD.19,20 For these groups of patients, the presence of underlying GERD should be suspected and investigated. Proton-pump

inhibitors could be empirically prescribed and this is a common clinical practice.19 Similarly, asymptomatic 上海皓元医药股份有限公司 GERD is also common in children, with unexplained pneumonia and recurrent asthma. These children should also be investigated and treated for GERD where appropriate.21 We do not understand yet the natural history of silent esophagitis. While the majority of cases are of milder grades, do we know whether they will evolve to more severe grades and Barrett’s esophagus without treatment? If so, this would be a cause for concern, given that 25% of Barrett’s esophagus and 40% of all esophageal adenocarcinomas occur in patients without, or with only minimal, prior reflux symptoms.2,22 This group of patients with silent GERD and erosive esophagitis clearly needs further, in-depth study and long-term follow up. “
“Lee WM, Hynan LS, Rossaro L, Fontana RJ, Stravitz RT, Larson AM, et al.; Acute Liver Failure Study Group. Intravenous N-acetylcysteine improves transplant-free survival in early stage non-acetaminophen acute liver failure. Gastroenterology 2009;137:856–886. (Reprinted with permission.) BACKGROUND & AIMS: N-acetylcysteine (NAC), an antidote for acetaminophen poisoning, might benefit patients with non-acetaminophen-related acute liver failure.