Dietetics-II Lecture Notes - Upper GIT PDF

Dietetics-II Lecture No.1: Upper GIT Gastroesophageal Reflux Disease (GERD) and Esophagitis Al Ayesha Farooq Lecturer-FEM Hamdard University- Karachi  Digestive disorders are among the most common pr...

Dietetics-II Lecture No.1: Upper GIT Gastroesophageal Reflux Disease (GERD) and Esophagitis Al Ayesha Farooq Lecturer-FEM Hamdard University- Karachi  Digestive disorders are among the most common problems in health care. Between 60 and 70 million people are affected by all digestive diseases, with more than 50 million ambulatory care visits made annually in the United States alone. More than 20 million diagnostic and surgical procedures involving the gastrointestinal (GI) tract are performed each year (CDC, 2014). Dietary habits and specific food types can play an important role in the onset, treatment, and prevention of many GI disorders. Nutrition therapy is integral in the prevention and treatment of malnutrition and deficiencies that can develop from a GI tract disorder. Diet and lifestyle modifications can improve a patient’s quality of life by alleviating GI symptoms and decreasing the number of health care visits and costs associated with GI disease.  THE ESOPHAGUS The esophagus is a muscular tube that has an average length of 25 cm in adults. It serves a single but very important function: conveying solids and liquids from the mouth to the stomach. It is lined with nonkeratinized stratified squamous epithelium, and submucosal glands secrete mucin, bicarbonate, epidermal growth factor, and prostaglandin E2, which protect the mucosa from gastric acid. The top of the esophagus is connected to the pharynx and the bottom of the esophagus is connected to the stomach at the cardia.  THE ESOPHAGUS It is highly muscular, with muscles arranged in a way to facilitate the passage of food. As a bolus of food is moved voluntarily from the mouth to the pharynx, the upper esophageal sphincter (UES) relaxes, the food moves into the esophagus, and peristaltic waves move the bolus down the esophagus; the lower esophageal sphincter (LES) relaxes to allow the food bolus to pass into the stomach. The esophageal transit time takes an average of 5 seconds when in an upright position, and up to 30 seconds when in a supine position.  The normal esophagus has a multitiered defense system that prevents tissue damage from exposure to gastric contents, including: LES contraction Normal gastric motility, Esophageal mucus, Tight cellular junctions, and Cellular pH regulators. Musculoskeletal disorders and motility disorders may result in dysphagia. For example, achalasia is characterized by a failure of esophageal neurons, resulting in a loss of ability to relax the LES and have normal peristalsis. Gastroesophageal Reflux Disease (GERD) and Esophagitis Etiology Gastroesophageal reflux (GER) is considered a normal physiologic process that occurs several times a day in healthy infants, children and adults. GER generally is associated with transient relaxation of the LES independent of swallowing, which permits gastric contents to enter the esophagus. Limited information is known about the normal physiology of GER in infants, but regurgitation and spitting up, as the most visible symptom, is reported to occur daily in 50% of all infants Gastroesophageal reflux disease (GERD) Gastroesophageal reflux disease (GERD) is a more serious, chronic or long-lasting form of GER and is defined as symptoms or complications resulting from the reflux of gastric contents into the esophagus or beyond, and even into the oral cavity (including larynx) or lung. In developed countries, the prevalence of GERD (defined by symptoms of heartburn [painful, burning sensation that radiates up behind the sternum of fairly short duration] and regurgitation, or both, at least once a week) is 10% to 20%, with a slightly lower prevalence in Asia.  Contd….. The types of GERD can be distinguished by esophagogastroduodenoscopy (EGD), which uses a fiberoptic endoscope to directly visualize the esophagus, stomach, and duodenum. GERD can be classified as the presence of symptoms without abnormalities or erosions on endoscopic examination (nonerosive disease or NERD), or GERD with symptoms and erosions present (ERD). ERD generally is associated with more severe and prolonged symptoms compared with NERD.  Contd… Some patients experience GERD symptoms primarily in the evening (nocturnal GERD), which has a greater impact on quality of life compared with daytime symptoms. Nocturnal GERD is associated significantly with severe esophagitis (inflammation of the esophagus) and intestinal metaplasia (Barrett’s esophagus) and can lead to sleep disturbance. Patients with ERD are more likely to be men, and women are more likely to have NERD. There is a definite relationship between GERD and obesity. Several meta-analyses suggest an association between body mass index (BMI), waist circumference, weight gain, and the presence of symptoms and complications of GERD. GERD is frequent during pregnancy, usually manifesting as heartburn, and may begin in any trimester. Significant predictors of heartburn during pregnancy are increasing gestational age, heartburn before pregnancy, and parity Gastroesophageal reflux disease (GERD) Chest pain may be a symptom of GERD, and distinguishing cardiac from noncardiac chest pain is required before considering GERD as a cause of chest pain. Although the symptoms of dysphagia can be associated with uncomplicated GERD, its presence warrants investigation for a potential complication including an underlying motility disorder, stricture, or malignancy. Patients with disruptive GERD (daily or more than weekly symptoms) have an increase in time off work and decrease in work productivity, and a decrease in physical functioning.  Pathophysiology The pathophysiology of GERD is complex. Box 27-1 describes possible mechanisms involved in GERD. Three components make up the esophagogastric junction: 1- The lower esophageal sphincter (LES), 2- The crural diaphragm, and 3- The anatomic flap valve. This esophagogastric junction functions as an anti reflux barrier. At the junction between the stomach and esophagus is the lower esophageal sphincter. This muscular sphincter acts as a valve that normally keeps food and stomach acid in the stomach, and prevents the stomach's contents from regurgitating back into the esophagus.  Pathophysiology The most common mechanism for reflux is transient LES relaxations, which are triggered by gastric distention and serve to enable gas venting from the stomach. On average, transient LES relaxations persist for about 20 seconds, which is significantly longer than the typical swallow-induced relaxation. For reflux to take place, pressure in the proximal stomach must be greater than the pressure in the esophagus. Patients with chronic respiratory disorders, such as chronic obstructive pulmonary disease (COPD), are at risk for GERD because of frequent increases in intraabdominal pressure. A chronically increased pressure also is seen during pregnancy and in overweight and obese people.  Pathophysiology Good peristaltic function is an important defense mechanism against GERD as prolonged acid clearance correlates with the severity of esophagitis and the presence of complication such as Barrett’s esophagus.  Barrett’s Esophagus Prolonged acid clearance correlates with the severity of esophagitis and the presence of complication such as Barrett's esophagus. Prolonged acid exposure can result in  Esophagitis  Esophageal erosions  Ulceration  Scaring  Dysphagia  Barrett's Esophagus (BE) is a precancerous condition in which the normal squamous epithelium of the esophagus is replaced by an abnormal columnar-lined epithelium known as Specialized intestinal Metaplasia (tissue that is similar to the intestinal lining) The exact cause of BE is unknown, but GERD is a risk factor for the condition.  Risk factors for BE include Prolonged history of GERD related symptoms (more than 5 years) Middle age White male Obesity Smoking Family history of BE or adenocarcinoma of the esophagus ESTROGEN may be protective and account for the lower incidence of BE in females.  Acute esophagitis May be caused by reflux, ingestion of a corrosive agent, viral or bacterial infection, intubation, radiation or eosinophilic infiltration. Eosinophilic esophagitis (EOE) is characterized by an isolated, severe eosinophilic infilteration of the esophagus manifested by GERD- like symptoms that may be caused by an immune response.  The severity of esophagitis resulting from the gastro-esophageal reflux is influenced by the  Composition  Frequency  Volume of the gastric reflux  Health of the mucosal barrier  Length of exposure of esophagus to the gastric reflux  Rate of gastric emptying Symptoms of esophagitis and GERD may impair the ability to consume an adequate diet and interfere with sleep, work, social events and overall quality of life.  Abnormalities of body Hiatal Hernia: May contribute to gastro-esophageal reflux and esophagitis. The esophagus passes through the diaphragm by way of the esophageal hiatus or ring. The attachment of the esophagus to the hiatal ring may be compromised, allowing a portion of the upper stomach to move above the diaphragm. Most common symptom is HEART BURN. When acid reflux occurs with a hiatal hernia, the gastric contents remains above the hiatus longer than normal. The prolonged acid exposure increases the risk of developing more serious esophagitis.  4 types: Types of Hiatal hernia 1- Type 1 SLIDING HIATAL MOST COMMON TYPE HERNIA Gastroesophageal junction is pushed above the diaphragm causing a symmetric herniation of the proximal stomach. Type 2 TRUE PARAESOPHAGEAL Fundus slides upward and moves HERNIA above the gastro esophageal junction Type 3 MIXED PARA ESOPHAGEAL Combined sliding and paraesophageal HERNIA herniation Type 4 COMPLEX PARA LESS COMMON FORM ESOPHAGEAL HERNIA Intra thoracic herniation of other organs, such as colon & small bowel into the hernia sac.  Pt’s with type 3 hiatal hernia may present with severe chest pain, vomiting, retching and hematemesis( vomiting of blood) because these hernias can twist and cause strangulation in the chest, which would be considered as surgical emergency. Some pts can present with IRON DEFIECIENCY ANEMIA without acute bleeding, because the diaphragm becomes so irritated that the patient may develop chronic blood loss.  MEDICAL & SURGICAL MANAGEMENT The primary medical treatment of esophageal reflux is Suppression of acid secretion. The aim in acid suppression therapy is to raise the gastric pH above 4 during periods when reflux is most likely to occur. PROTON PUMP INHIBITORS Which decrease acid production by the gastric parietal cells, have been associated with superior healing rates and decreased relapses. H2 receptors Milder forms of reflux are managed by H2 receptors( a type of histamine receptor on the gastric parietal cells) antagonists and antacids, which buffer gastric acid in the esophagus or stomach to reduce HEART BURN. Prokinetic agents : which increases propulsive contractions of the stomach, may be used in persons with delayed gastric emptying.  NISSEN FUNDOPLICATION Patients with severe GERD, 5-10% do not respond to medical therapy. This is the first described as a treatment for severe reflux esophagitis in 1956 and still the most commonly performed anti reflux surgery. During this procedure, the fundus or top portion of the stomach is wrapped 360 degrees around the lower esophagus and sutured in place to limit reflux.  Surgical therapy is considered for individuals who Have failed the medical management Those who opt for surgery despite successful medical management because of quality of life consideration, lifelong need for medication intake, expense of medications Those who experience complications of GERD i.e BE, peptic stricture Those who have esophageal manifestations i,e asthma, cough, hoarseness, chest pain, aspiration. Surgical approaches are reserved for children who have intractable symptom unresponsive to medical therapy or who are at risk for life threatening complications of GERD.  DIETARY GUIDELINES AFTER NISSEN FUNDOPLICATION Clear liquid diet after surgery Advance oral diet to soft, moist, solid foods. Follow soft, moist food diet for 2 months. Small & frequent meals. Swallow small bites of food and chew thoroughly to allow an easy passage through the esophagus. Avoid use of straw to consume liquids. Drink slowly Avoid foods that may cause backflow of stomach contents i.e citrus fruits and juices, tomatoes, pineapple, alcohol, caffeine, chocolate, carbonated beverages, peppermint, fatty and fried foods, spicy foods, vinegar or vinegar containing foods.  Avoid dry foods that are hard to pass through the esophagus i,e bread, steak, raw vegetables, rolls, dry chicken, raw fruits, peanut butter, other dry meats or anything with skin, seeds and nuts Avoid any food that may cause discomfort After 2 months, starts to incorporate new foods into the diet. Try one new food item or beverage at a time. By 3-6 months, patient should be able to tolerate most foods. Consult doctor or dietitian if having difficulty eating or losing weight.  LIFE STYLE MODIFICATIONS &MNT The first step in symptom management of GERD should consist of changes in lifestyle, including Diet. The main factors that triggers reflux symptoms are:  Caffeine  Alcohol  Tobacco  Stress Initial recommendations should focus on meal size and content. Eating small rather than larger meals reduces the probability that gastric contents will reflux into the esophagus. Obesity: contributing factor for GERD and hiatal hernia. It increases the intragastric pressure and weight reduction may reduce acid contact time in the esophagus leading to decreased reflux symptoms.  The frequent advice is to elevate the head of the bed by 6 to 8 inches would be rational for patients who have reflux episodes at night. Frequent bending over should be avoided Use of loose fitted garments in the waist area also is thought to decrease the risk of reflux. Food such as Carminatives ( peppermint and spearmint) and coffee have been reported to lower LES pressure, but little research has been done to associate the symptoms of GERD. Fermented alcoholic beverages such as beer and wine stimulate the secretion of gastric acid and should be limited Carbonated beverages enhance gastric distention, which increases transient LES relaxations. Highly acidic foods such as citrus juices and tomatoes should be avoided because they cause pain when the esophagus is already inflamed.  In patients with GI lesions, the use of foods highly seasoned with chili powder and pepper can cause discomfort. The type of chili and the amount of capsaicin consumed make a difference. Chewing gum has been shown to increase salivary secretions, which help raise esophageal pH, but no studies have demonstrated its efficacy compared with other lifestyle measures. Limiting or avoiding aggravating foods nay improve symptoms in some individuals.  Lifestyle changes to treat GERD in INFANTS May involve a combination of feeding changes and positioning therapy. Modifying the maternal diet if infant is breastfed, changing formulas, and reducing the feeding volume while increasing the frequency of feedings may be effective strategy to address GERD in many infants. Use of tobacco products is contraindicated with reflux. Cigarette smoking should be stopped because it is associated with decreased LES pressure and decreased salivation , thus causing prolonged acid clearance. Smoking tobacco products also compromises GI integrity and increases the risk of esophageal and other cancers.