A Bench to Bedside Primer

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Note: The lesson plans and opinions in this report are those of the authors and do not necessarily reflect the opinions of any of the supporting institutions or the editors.

Appropriate citation: Eldridge-Sandbo, Mary Bench to Bedside Primer: Gastrointestinal Physiology and Appendicitis (APS Archive of Teaching Resources Item #5978). [Online]. Bethesda, MD: American Physiological Society, 2011. http://www.apsarchive.org/my/submit9.cfm?submissionID=5978

Editor’s notes: This four-page “primer” (a booklet of basic principles) highlights a scientific interest of the teacher producing it in ONE of three physiology topics: cardiovascular (CV), renal (REN), or gastrointestinal (GI) physiology. This primer should be readable by middle to high school students or the general public to help inform them about the organ system, diseases that affect it, and basic and clinical research being done on it. This resource can be used as a sample of the primer a teacher wishes to have their students produce or as an educational tool to explain basic and clinical research.

Website URLs listed in this resource were current as of publication, but may now be obsolete. If you know of a replacement URL, please suggest it in the resource’s “Comments” section.

Errata Page follows this resource.

Disclaimer: This activity was created by the author and reviewed by the American Physiological Society. Any interpretations, statements, or conclusions in this publication are those of the author and do not necessarily represent the views of either the American Physiological Society or the funding agencies supporting the professional development program in which the author participated.

Frontiers in Physiology © The American Physiological Society www.frontiersinphys.org Permission is granted for workshop/classroom use with appropriate citation

Errata Page

What causes appendicitis? It is important to note that the cause of appendicitis is not known. Also, while appendicitis can follow an infection of the digestive tract, it is not "caused by an infection of the intestinal tract".

Frontiers in Physiology © The American Physiological Society www.frontiersinphys.org Permission is granted for workshop/classroom use with appropriate citation

Gastrointestinal (GI) Physiology When you swallow a bite of your favorite food, it is easy to think about taking another bite. It is easy to forget that each bite of food, which enters your mouth, begins a 30-hour, nine- meter long journey through muscles, acids, enzymes, and bacteria as it travels through the gastrointestinal (GI) tract of the digestive system. This journey is not exactly glamorous, but you cannot live without it because it provides your cells with the nutrients and energy they need to keep you alive.

Organs of the GI tract: Mouth, Esophagus, Stomach, Small intestine, Large intestine Accessory organs: Pancreas, Liver, Gallbladder

A summary… It all begins in the mouth, where food is chewed and moistened. Chemical digestion begins when salivary enzymes start carbohydrate digestion. When food is swallowed, it enters the esophagus, which is lined with muscles that contract in a wave-like motion called peristalsis to move the food into the stomach in less than 10 seconds! In the stomach, enzymes and acids begin protein digestion and muscular contractions transform the lump of food into a semi- liquid form known as chyme. Bit by bit, the chyme enters the upper part of the small intestine, called the duodenum, where bile, which is secreted by the gall gladder, helps break down fats and intestinal and pancreatic enzymes complete chemical digestion.

The remainder of the small intestine is lined with tiny projections, called villi, which allow nutrients to be absorbed into the bloodstream and transported to the liver. The liver carries out many functions to be sure that nutrients are stored or released as needed in the correct form for the body.

Once digestion and absorption are completed, the remaining, undigested food, called feces, and a lot of water enter the large intestine, which is home to many harmless bacteria. The bacteria digest, produce some vitamins, and help protect against disease-causing bacteria! Finally, water is sent back http://commons.wikimedia.org/wiki/File:Digestive_system_diagram.edit.svg to the blood stream and the feces is stored in the lowest portion of the large intestine, called the rectum, until it is sent out of the body through the anus.

References • WebMD Digestive Disorders Health System: http://www.webmd.com/digestive- disorders/digestive-system • National Geographic. The Digestive System: http://science.nationalgeographic.com/science/health-and-human-body/human- body/digestive-system-article.html • U.S. Department of Health and Human Services. National Institutes of Health. National Digestive Diseases Information Clearninghouse. Your Digestive System and How it Works: http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/index.aspx Appendicitis

What is the appendix? The appendix is a tube measuring about seven centimeters in length located at the point where the small intestine meets the large intestine. If this structure has a function in humans, it has not been discovered yet. It is known that people can live normal lives without an appendix. This structure is technically known as the vermiform appendix.

What is appendicitis? When the appendix becomes inflamed, it is called appendicitis. The inflammation can lead to infection, which, if not treated, can lead to a rupture, or bursting of the appendix.

What causes appendicitis? The appendix can become inflamed when it is blocked by something in the digestive tract, or when the digestive tract becomes infected.

What are the symptoms of appendicitis? Pain in the abdomen is one of the most common symptoms of appendicitis. Sometimes, the pain is more localized on the right side. Other symptoms include nausea, vomiting, changes in bowl movements, and fever.

What is the treatment for appendicitis? The routine treatment for appendicitis is an appendectomy, which is the surgical removal of the appendix. There are several different forms of this surgery, depending on the patient and severity of infection. This is one of the most common emergency surgeries in the United States. The goal of the surgery is to remove the appendix before it ruptures because a ruptured appendix can spread infection throughout the abdominal cavity. Surgery is usually followed with antibiotics in order to treat infection.

Who is at risk for appendicitis? Anyone can get appendicitis, but family history could increase the risk of this problem. Children, younger than two, and adults, older than 70, are at a greater risk for a ruptured appendix.

Can appendicitis be prevented? Current resources report no prevention for appendicitis, but a diet with fiber can help things move most efficiently through the digestive tract, which can prevent a blockage that could lead to appendicitis.

References: PubMedHealth National Center for Biotechnology Information, U.S. National Library of Medicine:http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001302/ WebMD:http://www.webmd.com/digestive-disorders/digestive-diseases-appendicitis University of Maryland Medical Center: http://www.umm.edu/altmed/articles/appendicitis- 000014.htm

Recent Research Related to Appendicitis

Appendicitis is nearly always treated by the surgical removal of the appendix (Vans et al., 2011). Over the years, however, research has explored the effectiveness of treating appendicitis with antibiotics. Potential benefits to this non-surgical approach include avoiding surgical risks and reducing financial costs. (Liu, Ahanchi, Pisaneschi, Lin, & Walter, 2007). At this point, there are conflicting results as to whether antibiotic treatment is a beneficial alternative to surgery for patients with acute appendectomy without other symptoms or complications (Vans et al., 2011).

A 2007 study in Chicago compared the results of 151 patients whose acute appendicitis was treated with traditional surgery were compared to 19 patients with similar symptoms who were treated with antibiotics (Liu et al., 2007). The results of this study were that antibiotic treatment was equally safe as an emergency appendectomy (Liu et al., 2007). A more recent study in Korea studied 107 patients, with symptoms of acute appendicitis, who were first treated with antibiotics (Park et al., 2011). Of the 107 patients, 97 were successfully treated with antibiotics (Park et al., 2011). These results led Park et al., (2011) to conclude that antibiotic treatment is not only equally effective to surgery, but eliminates the risks associated with surgery.

Not all research investigating the effectiveness of antibiotic therapy compared to surgical removal of the appendix has come to the same conclusion. Vons et al. (2011) conducted a larger, randomized study consisting of 243 patients. Nearly half of the patients received antibiotic treatment, while the other half underwent an appendectomy (Vons et al., 2011). The authors of this study explained that their research was the first one that randomized their patients after appendicitis had been diagnosed (Vons et al., 2011). They concluded that antibiotic treatment was not as effective as surgery and recommended that appendectomy was still the best way to treat this condition.

The authors of all three studies shared the conclusion that through diagnosis of appendicitis is very important so that the best treatment can be determined. Diagnosis has been improved through the combined results of laboratory tests, pain scales, abdominal tenderness, and radiological examinations (Vons, 2011).

References:

Liu, K., Ahanchi, S., Pisaneschi, M., Lin, I., & Walter, R. (2007). Can acute appendicitis be treated by antibiotics alone? The American Surgeon, 73, 1161-1165. Retrieved from http://cms.sesc.org/opencms/opencms/as/

Park, H., Byoung-Seup, K., Lee, B. (2011). Efficacy of short-term antibiotic therapy for consecutive patients with mild appendicitis. The American Surgeon, 77, 752-755. Retrieved from http://cms.sesc.org/opencms/opencms/as/

Vons, C., Barry, C., Maitre, S., Pautrat, K., Leconte, M., Costaglioli, B., Karoui, M., Alves, A., Dousset, B., Valleur, P., Falissard, B., Franco, D. (2011). Amoxicillin plus clavulanic acid versus appendicectomy for treatment of acute uncomplicated appendicitis: an open-label, non-inferiority, randomized controlled trial. The Lancet, 377, 1573-79. Retrieved from http://www.thelancet.com

Clinical trial for children following surgery for a ruptured appendix Experiencing a ruptured appendix, and the surgery that follows, can be difficult for a child and his or her family. Unfortunately, there can be additional difficulties during the recuperation period as well. After surgery for a ruptured appendix, the intestines usually stop their normal movement for several days in response to the infection and surgery. This lack of intestinal function is known as ileus. Ileus can result in bloating, pain, and nausea. In order to reduce these unpleasant symptoms, children are not allowed to eat or drink anything until the intestines begin to function. While nutrients and fluids are still provided through an IV, the patient must wait for the intestines to return to their normal function before they can eat, drink, and truly be on the road to recovery and prepare to go home from the hospital.

A study has been proposed to investigate whether simply chewing gum, or wearing a motion sickness band will prompt the intestines to start working more quickly. A Phase III study has been listed with the National Institute of Health (NCT00879294). Although recruitment of participants has not begun, this study will be recruiting 60 patients at Brenner Children's Hospital Winston Salem, North Carolina.

Overview of this study: According to the proposed description, children ranging from six to 18 years of age, who have had surgery for a perforated appendix, will be eligible for this study. The study proposes three groups. Patients in one group will wear a motion sickness wristband, patients in another group will chew gum 20 minutes for four times a day, and those in a control group will do neither. The length of time required for intestinal movement to return will be measured and compared.

Who is not eligible for this study: Patients who are under the age of six years, as well as those who cannot chew gum, are not eligible for this study.

Potential benefits of this study: Both chewing gum and motion sickness wristbands are inexpensive, drug free treatments. If intestinal function can be restored earlier by either of these measures, children can begin to eat and drink sooner, which could speed the process of recuperation.

For more information: Pranikoff, T. (Wake Forest University). The Effect of Gum Chewing on Postoperative Ileus. http://clinicaltrials.gov/ct2/show/study/NCT00879294

Reflection: While this study seems very simple, a simple solution to a problem that can cause extreme discomfort and prolonged hospitalization certainly seems worth further study. An Internet search of this topic shows that similar studies dealing with gum chewing have shown promising results in adults following other types of abdominal surgeries. It seems that this, and other studies, could help shed light on the peristaltic function of the intestines and provide an option that could lead to a faster recuperation period for patients.