National Registry Paramedic Exam: Gastrointestinal Emergencies

The acute abdomen is a common complaint that patients offer to paramedics. This can involve everything in the abdomen, including abdominal aortic aneurysms or ovarian cysts, but for our purposes here, the focus will be on GI emergencies.

Anatomy and Physiology
Two types of digestion can occur. First, intracellular digestion, as a part of metabolism, involves the oxidation of glucose and fatty acids for energy. However, our diets do not consist of pure glucose and fatty acids; rather, these substances must be extracted from our food. The process by which these nutrients are obtained from food occurs within the lumen of the alimentary canal and is known as extracellular digestion. This is technically “outside” the body, as it occurs outside cell borders. The alimentary canal runs from the mouth to the anus and is sectioned off by sphincters, or circular smooth muscles around the canal that can contract to allow compartmentalization of function.
The human digestive tract has specialized sections with different functional roles. The most basic functional distinction is between digestion and absorption. Digestion involves the breakdown of food into its constituent organic molecules: starches and other carbohydrates into monosaccharides, lipids (fats) into free fatty acids and glycerol, and proteins into amino acids. Digestion can be subdivided into mechanical and chemical processes. Mechanical digestion is the physical breakdown of large food particles into smaller food particles, but it does not involve breaking chemical bonds. Chemical digestion is the enzymatic cleavage of chemical bonds, such as the peptide bonds of proteins or the glycosidic bonds of starches. Absorption involves the transport of the products of digestion from the digestive tract into the circulatory system for distribution to the body’s tissues and cells.
The digestive tract begins with the oral cavity (mouth) and is followed by the pharynx, a shared pathway for both food entering the digestive system and air entering the respiratory system. From the pharynx, food enters the esophagus, which transports food to the stomach. From the stomach, food travels to the small intestine and then the large intestine. Finally, waste products of digestion enter the rectum, where feces are stored until the appropriate time of release. In addition to the actual organs of the digestive tract, the salivary glands, pancreas, liver, and gallbladder help provide the enzymes and lubrication necessary to aid the digestion of food.


Figure: Anatomy of the Digestive System

The enteric nervous system is a collection of 100 million neurons that govern the function of the gastrointestinal system. These neurons are present in the walls of the digestive tract and trigger peristalsis, or rhythmic contractions of the gut tube, to move materials through the system. This system can function independently of the brain and spinal cord, although it is heavily regulated by the autonomic nervous system. The parasympathetic division is involved in the stimulation of digestive activities, increasing secretions from exocrine glands and promoting peristalsis. The sympathetic division is involved in the inhibition of these activities. The fact that so often people feel sleepy and lethargic after eating a big meal (often called a food coma colloquially) is caused, in part, by parasympathetic activity. On the other hand, during periods of high sympathetic activity, blood flow is decreased to the digestive tract, and gut motility slows significantly.

To supply the body with nutrients, people must ingest (eat) food. Several hormones are involved with feeding behavior, including antidiuretic hormone (ADH or vasopressin), aldosterone, glucagon, ghrelin, leptin, and cholecystokinin. ADH and aldosterone trigger the sensation of thirst, encouraging the behavior of fluid consumption. Glucagon, secreted by the pancreas, and ghrelin, secreted by the stomach and the pancreas, stimulate feelings of hunger. Leptin and cholecystokinin do the opposite, stimulating feelings of satiety. Digestion begins in the oral cavity and continues in the stomach and the first part of the small intestine, known as the duodenum.

Oral Cavity
The oral cavity plays a role in both the mechanical and chemical digestion of food. Mechanical digestion in the mouth involves the breaking up of large food particles into smaller particles by using the teeth, tongue, and lips. This process is called mastication (chewing). Chewing helps to increase the surface-area-to-volume ratio of the food, allowing for more surface area for enzymatic digestion as it passes through the gut tube. It also moderates the size of food particles entering the lumen of the alimentary canal; food particles that are too large create an obstructive risk in the tract.
Chemical digestion begins the breakdown of chemical bonds in the macromolecules that make up food. This relies on enzymes from saliva produced by the 3 pairs of salivary glands. Saliva also aids mechanical digestion by moistening and lubricating food. The salivary glands, like all glands of the digestive tract, are innervated by the PNS. The presence of food in the oral cavity triggers a neural circuit that ultimately leads to increased parasympathetic stimulation of these glands. Salivation also can be triggered by signals that food is near, such as smell or sight. Saliva contains salivary amylase, also known as ptyalin, and lipase. Salivary amylase is capable of hydrolyzing starch into smaller sugars (maltose and dextrins), and lipase catalyzes the hydrolysis of lipids. The amount of chemical digestion that occurs in the mouth is minimal, though, because the food does not stay in the mouth for long. Our muscular tongue forms the food into a bolus, which is forced back to the pharynx and swallowed.

Pharynx
The pharynx is the cavity that leads from the mouth and posterior nasal cavity to the esophagus. The pharynx connects to not only the esophagus but also the larynx, which is a part of the respiratory tract. The pharynx can be divided into 3 parts: the nasopharynx (behind the nasal cavity), the oropharynx (at the back of the mouth), and the laryngopharynx (above the vocal cords). Food is prevented from entering the larynx during swallowing by the epiglottis, a cartilaginous structure that folds down to cover the laryngeal inlet. Failure of this mechanism can lead to the aspiration of food and choking.

Esophagus
The esophagus is a muscular tube that connects the pharynx to the stomach. The top third of the esophagus is composed of skeletal muscle, the bottom third is composed of smooth muscle, and the middle third is a mixture of both. What does this mean in terms of nervous control? Although the top of the esophagus is under somatic (voluntary) motor control, the bottom—and most of the rest of the gastrointestinal tract, for that matter—is under autonomic (involuntary) nervous control. The rhythmic contraction of smooth muscle that propels food toward the stomach is called peristalsis. Under normal circumstances, peristalsis proceeds down the digestive tract. However, certain conditions, such as exposure to chemicals, infectious agents, physical stimulation in the posterior pharynx, and even cognitive stimulation, can lead to a reversal of peristalsis in the process of emesis (vomiting).
Swallowing is initiated in the muscles of the oropharynx, which constitute the upper esophageal sphincter. Peristalsis squeezes, pushes, and propels the bolus toward the stomach. As the bolus approaches the stomach, a muscular ring known as the lower esophageal sphincter (cardiac sphincter) relaxes and opens to allow the passage of food.

Stomach
The 3 main energy sources are carbohydrates, fats, and proteins. As mentioned earlier, the chemical digestion of carbohydrates and fats is initiated in the mouth. No mechanical or chemical digestion takes place in the esophagus, except for the continued enzymatic activity initiated in the mouth by salivary enzymes. Thus, digestion that occurs prior to the entrance of the bolus into the stomach is minimal compared with digestion that occurs in the stomach and small intestine.
The stomach is a highly muscular organ with a capacity of approximately 2 L. In humans, the stomach is located in the upper left quadrant of the abdominal cavity, under the diaphragm. This organ uses hydrochloric acid and enzymes to digest food, creating a fairly harsh environment, and its mucosa is quite thick to prevent autodigestion. The stomach can be divided into 4 main anatomical divisions: the fundus and body, which contain mostly gastric glands, and the antrum and pylorus, which contain mostly pyloric glands. The internal curvature of the stomach is called the lesser curvature; the external curvature is called the greater curvature. The lining of the stomach is thrown into folds called rugae.


Figure: Anatomy of the Stomach

The mucosa of the stomach contains gastric glands and pyloric glands. The gastric glands respond to signals from the vagus nerve of the PNS, which is activated by the brain in response to the sight, taste, and smell of food. Gastric glands have 3 different cell types: mucous cells, chief cells, and parietal cells. Mucous cells produce the bicarbonate-rich mucus that protects the muscular wall from the harshly acidic (pH = 2) and proteolytic environment of the stomach.
Gastric juice is a combination of secretions from the other 2 cell types in the gastric glands. The chief cells secrete pepsinogen, which is the inactive, zymogen form of pepsin, a proteolytic enzyme. Hydrogen ions in the stomach, secreted by parietal cells as hydrochloric acid, cleave pepsinogen to pepsin. Pepsin digests proteins by cleaving peptide bonds near aromatic amino acids, resulting in short peptide fragments. Because pepsin is activated by the acidic environment, it follows that pepsin is most active at a low pH. This is a unique characteristic among human enzymes because most human enzymes are most active at physiological pH. Stomach acid also kills most harmful bacteria (with the exception of Helicobacter pylori, infection with which is usually asymptomatic but can cause inflammation, ulcers, and even certain gastric cancers). The acidic environment also helps denature proteins and can break down some intramolecular bonds that hold food together. In addition to HCl, parietal cells secrete intrinsic factor, a glycoprotein involved in the proper absorption of vitamin B12.
The pyloric glands contain G-cells that secrete gastrin, a peptide hormone. Gastrin induces the parietal cells in the stomach to secrete more HCl and signals the stomach to contract, mixing its contents. The digestion of solid food in the stomach results in an acidic, semifluid mixture known as chyme. The combined mechanical and chemical digestive activities of the stomach result in a significant increase in the surface area of the now unrecognizable food particles, so when the chyme reaches the small intestine, the absorption of nutrients from it can be maximized. A few substances can be absorbed directly from the stomach (such as alcohol and aspirin), but the stomach is mainly an organ of digestion.

Duodenum
The small intestine consists of 3 segments: the duodenum, the jejunum, and the ileum. The small intestine is quite long, up to 7 m. The duodenum is responsible for the majority of chemical digestion and has some minor involvement in absorption. However, most of the absorption in the small intestine takes place in the jejunum and the ileum.
Food leaves the stomach through the pyloric sphincter and enters the duodenum. The presence of chyme in the duodenum causes the release of brush-border enzymes such as disaccharidases (maltase, isomaltase, lactase, and sucrase) and peptidases (including dipeptidase). Brush-border enzymes are present on the luminal surface of cells lining the duodenum and break down dimers and trimers of biomolecules into absorbable monomers. The duodenum also secretes enteropeptidase, which is involved in the activation of other digestive enzymes from the accessory organs of digestion. Finally, it secretes hormones such as secretin and cholecystokinin (CCK) into the bloodstream.
The disaccharidases digest disaccharides. Maltase digests maltose, isomaltase digests isomaltose, lactase digests lactose, and sucrase digests sucrose. The lack of a particular disaccharidase causes an inability to break down the corresponding disaccharide. Then bacteria in the intestines are able to hydrolyze that disaccharide, producing methane gas as a byproduct. In addition, undigested disaccharides can have an osmotic effect, pulling water into the stool and causing diarrhea. This is why people who are lactose intolerant have symptoms of bloating, flatulence, and possibly diarrhea after ingesting dairy products.
Peptidases break down proteins (or peptides, as the name implies). Aminopeptidase is a peptidase secreted by glands in the duodenum that removes the N-terminal amino acid from a peptide. Dipeptidases cleave the peptide bonds of dipeptides to release free amino acids. Unlike carbohydrates, which must be broken down into monosaccharides for absorption, dipeptides and even tripeptides can be absorbed across the small intestine wall.
Enteropeptidase (formerly called enterokinase) is an enzyme critical for the activation of trypsinogen, a pancreatic protease, to trypsin. Trypsin then initiates an activation cascade. Enteropeptidase also can activate procarboxypeptidases A and B to their active forms.
Secretin is a peptide hormone that causes pancreatic enzymes to be released into the duodenum. It also regulates the pH of the digestive tract by reducing HCl secretion from parietal cells and increasing bicarbonate secretion from the pancreas. Secretin also is an enterogastrone, a hormone that slows motility through the digestive tract. Slowing of motility allows increased time for digestive enzymes to act on chyme—especially fats.
Finally, CCK is secreted in response to the entry of chyme (specifically, amino acids and fat in the chyme) into the duodenum. This peptide hormone stimulates the release of both bile and pancreatic juices and also acts in the brain, where it promotes satiety. Bile is a complex fluid composed of bile salts, pigments, and cholesterol. Bile salts are derived from cholesterol. They are not enzymes and therefore do not directly perform chemical digestion. However, bile salts serve an important role in the mechanical digestion of fats and ultimately facilitate the chemical digestion of lipids. Bile salts have hydrophobic and hydrophilic regions, allowing them to serve as a bridge between aqueous and lipid environments. In fact, bile salts are much like the common soaps and detergents used to wash our hands, clothes, and dishes. In the small intestine, bile salts emulsify fats and cholesterol into micelles. Without bile, fats would spontaneously separate out of the aqueous mixture in the duodenum and would not be accessible to pancreatic lipase, which is water soluble. In addition, these micelles increase the surface area of the fats, increasing the rate at which lipase can act. Ultimately, proper fat digestion depends on both bile and lipase. Bile gets the fats into the solution and increases their surface area by placing them in micelles (mechanical digestion). Then, lipase can come in to hydrolyze the ester bonds holding the lipids together (chemical digestion).
CCK also promotes the secretion of pancreatic juices into the duodenum. Pancreatic juices are a complex mixture of several enzymes in a bicarbonate-rich alkaline solution. This bicarbonate helps neutralize acidic chyme, as well as provides an ideal working environment for each of the digestive enzymes, which are most active around pH 8.5. Pancreatic juices contain enzymes that can digest all 3 types of nutrients: carbohydrates, fats, and proteins.


Figure: Hormonal Control of the Exocrine Pancreas

Accessory Organs of Digestion
Digestion is a complex process that requires the release of enzymes from not only the cells directly lining the alimentary canal but also the pancreas, liver, and gallbladder. Collectively, these organs—which all originate as outgrowths of endoderm from the gut tube during development—are called accessory organs of digestion.

Pancreas
The pancreas serves 2 quite different roles in the body, reflecting its exocrine and endocrine functions. The endocrine functions of the pancreas include the release of insulin, glucagon, and somatostatin—peptide hormones necessary for the maintenance of proper blood sugar levels. The hormonal function of the pancreas is limited to cells residing in the islets of Langerhans scattered throughout the organ. The bulk of the pancreas, however, is made of exocrine cells called acinar cells that produce pancreatic juices. As mentioned earlier, pancreatic juices are bicarbonate-rich alkaline secretions containing many digestive enzymes that work on all 3 classes of biomolecules. Pancreatic amylase breaks down large polysaccharides into small disaccharides and is therefore responsible for carbohydrate digestion. The pancreatic peptidases (trypsinogen, chymotrypsinogen, and carboxypeptidases A and B) are released in their zymogen form, but once activated are responsible for protein digestion. Enteropeptidase, produced by the duodenum, is the master switch. It activates trypsinogen to trypsin, which can then activate the other zymogens, and also activates procarboxypeptidases A and B to their active forms. Finally, the pancreas secretes pancreatic lipase, which is capable of breaking down fats into free fatty acids and glycerol.
Pancreatic juices are transferred to the duodenum via a duct system that runs along the middle of the pancreas. Like all exocrine cells, acinar cells secrete their products into ducts. These ducts then empty into the duodenum through the major and minor duodenal papillae.


Figure: Anatomy of the Pancreas

Liver
The liver is located in the upper right quadrant of the abdomen and contains 2 unique structures for communicating with the digestive system. First, bile ducts connect the liver with both the gallbladder and small intestine. Bile is produced in the liver and travels down these ducts, where it may be stored in the gallbladder or secreted into the duodenum. The liver also receives all blood draining from the abdominal portion of the digestive tract through the hepatic portal vein. This nutrient-rich blood can be processed by the liver before draining into the inferior vena cava on its way to the right side of the heart. For example, the liver takes up excess sugar to create glycogen, the storage form of glucose, and stores fats as triacylglycerols. The liver also can reverse these processes, producing glucose for the rest of the body through glycogenolysis and gluconeogenesis and mobilizing fats in lipoproteins. The liver detoxifies both endogenous compounds (those made in the body) and exogenous compounds (those brought in from the environment). For example, the liver modifies ammonia, a toxic waste product of amino acid metabolism, to urea, which can be excreted by the kidneys. The liver also detoxifies and metabolizes alcohol and medications. Some drugs actually require activation by the enzymes of the liver. In addition, some drugs cannot be taken orally because modification of these drugs by the liver renders the drugs inactive.
Bile production is 1 of the most significant jobs of the liver vis-à-vis the digestive system. As mentioned earlier, bile is composed of bile salts, pigments, and cholesterol. Bile salts are amphipathic molecules that can emulsify fat in the digestive system. The major pigment in bile is bilirubin, which is a byproduct of the breakdown of hemoglobin. Bilirubin travels to the liver, where it is conjugated (attached to a protein) and secreted into the bile for excretion. If the liver is unable to process or excrete bilirubin (from liver damage, excessive red blood cell destruction, or blockage of the bile ducts), jaundice or yellowing of the skin may occur.
In addition to bile production, processing of nutrients, detoxification, and drug metabolism, the liver also synthesizes certain proteins necessary for proper body function. These proteins include albumin, a protein that maintains plasma oncotic pressure and also serves as a carrier for many drugs and hormones as well as clotting factors used during blood coagulation.

Gallbladder
The gallbladder is located just beneath the liver and both stores and concentrates bile. After the release of CCK, the gallbladder contracts and pushes bile out into the biliary tree. The bile duct system merges with the pancreatic duct before emptying into the duodenum.
The gallbladder is a common site of cholesterol or bilirubin stone formation. This painful condition causes inflammation of the gallbladder. The stones also may travel into the bile ducts and may get stuck in the biliary tree. In some cases, stones can get caught just before entering the duodenum, resulting in blockage of not only the biliary tree, but the pancreatic duct as well, causing pancreatitis.

Absorption and Defecation
The absorption of nutrients primarily occurs in the small intestine, especially in the jejunum and the ileum. The large intestine largely absorbs water.

Jejunum and Ileum
The small intestine consists of 3 segments: the duodenum, the jejunum, and the ileum. As discussed previously, the duodenum is primarily involved in digestion. The jejunum and ileum are involved in the absorption of nutrients. The small intestine is lined with villi, which are small, fingerlike projections from the epithelial lining. Each villus has many microvilli, drastically increasing the surface area available for absorption. In addition, at the middle of each villus is a capillary bed for the absorption of water-soluble nutrients and a lacteal, a lymphatic channel that takes up fats for transport into the lymphatic system.


Figure: Structure of a Villus

Simple sugars, such as glucose, fructose, and galactose, and amino acids are absorbed by secondary active transport and facilitated diffusion into the epithelial cells lining the small intestine. Then, these substances move across the epithelial cells into the intestinal capillaries. Blood is constantly passing by the epithelial cells in the capillaries, carrying the carbohydrate and amino acid molecules away from the epithelial cells. This creates a concentration gradient, such that the blood always has a lower concentration of monosaccharides and amino acids than inside the epithelial cells. Thus, simple carbohydrates and amino acids diffuse from the epithelial cells into the capillaries. The absorbed molecules then go to the liver via the hepatic portal circulation.
What about fats? Small fatty acids will follow the same process as carbohydrates and amino acids by diffusing directly into the intestinal capillaries. These fatty acids do not require transporters because they are nonpolar, so they can easily traverse the cellular membrane. Larger fats, glycerol, and cholesterol move separately into the intestinal cells but then reform into triglycerides. The triglycerides and esterified cholesterol molecules are packaged into chylomicrons. Rather than entering the bloodstream, chylomicrons enter the lymphatic circulation through lacteals, small vessels that form the beginning of the lymphatic system. These lacteals converge and enter the venous circulation through the thoracic duct in the base of the neck, which empties into the left subclavian vein.
Vitamins also are absorbed in the small intestine. Vitamins can be categorized as either fat soluble or water soluble. Because there are only 4 fat-soluble vitamins (A, D, E, and K), these can be easily memorized. All other vitamins (B complex and C) are water soluble. Fat-soluble vitamins dissolve directly into chylomicrons to enter the body. A failure to digest and absorb fat properly, which can be caused by pathologies in the liver, gallbladder, pancreas, or small intestine, may lead to deficiencies of fat-soluble vitamins. The water-soluble vitamins are absorbed, along with water, amino acids, and carbohydrates, across the endothelial cells of the small intestine, passing directly into the plasma.
In addition to fats, carbohydrates, amino acids, and vitamins, the small intestine also absorbs water. Much of the water in chyme is actually the result of secretions. The average person may consume up to 2 L of fluid per day, but secretions into the upper gastrointestinal tract may total up to 7 L of fluid per day. To maintain proper fluid levels within the body, much of this fluid must be reabsorbed by osmosis. As solutes are absorbed into the bloodstream, water is drawn with it, eventually reaching the capillaries. Water passes not only transcellularly (across the cell membrane) but also paracellularly (squeezing between cells) to reach the blood.

Large Intestine
The final part of the gastrointestinal tract is the large intestine. It is primarily involved in water absorption. The large intestine has a larger diameter but shorter length than the small intestine. It is divided into 3 major sections: the cecum, the colon, and the rectum. The cecum is simply an outpocketing that accepts fluid exiting the small intestine through the ileocecal valve and is the site of attachment of the appendix. The appendix is a small, fingerlike projection that was once thought to be vestigial, although recent evidence suggests that it may have a role in warding off certain bacterial infections and repopulating the large intestine with normal flora after episodes of diarrhea. Inflammation of the appendix (appendicitis) is a surgical emergency; in fact, it is the most common reason for an unscheduled surgery in the United States.
The colon itself is divided into the ascending, transverse, descending, and sigmoid colons. Its main function is to absorb water and salts (such as sodium chloride) from the undigested material left over from the small intestine. While the small intestine actually absorbs much more water overall than the colon, the colon primarily concentrates the remaining material to form feces with just the right amount of residual water. Too much water absorbed from the feces and constipation will result; too little water absorbed and its off to the races with diarrhea. 
Finally, the rectum serves as a storage site for feces, which consists of indigestible material, water, bacteria (Escherichia coli and others), and certain digestive secretions that are not reabsorbed (enzymes and some bile). The anus is the opening through which wastes are eliminated and consists of 2 sphincters: the internal and external anal sphincters. The external anal sphincter is under voluntary control (somatic), but the internal anal sphincter is under involuntary control (autonomic).
The large intestine—and even the small intestine—is home to many different species of bacteria. In fact, 30% of the dry matter in stool consists of bacteria. Most of these bacteria are anaerobes, but the cecum also is home to many aerobic bacteria. This relationship is symbiotic: the bacteria are provided with a steady source of food, and the byproducts produced by the bacteria are beneficial to humans. For example, bacteria in the gut produce vitamin K, which is essential for the production of clotting factors, and biotin (vitamin B7), which is a coenzyme for many metabolic enzymes.

Assessment of Acute Abdomen
As with any patient, the assessment begins with evaluating the patient for conditions that are more serious and more likely to be associated with death. Evaluating a patient’s ABCs and treating any problems with that should be of the highest priority. For example, acute coronary syndromes could present as pain in the upper abdomen, yet the patient may never complain of any chest-related problems. Nervous, respiratory, and cardiovascular problems are rarely directly related to an abdominal problem. Findings related to these systems may not leave time for a thorough evaluation of the abdomen, even if that is the patient’s chief complaint. If there are no discernible derangements of the heart, breathing, blood pressure, level of consciousness, or CNS functions (such as CVA or syncope), completing a secondary survey related to the abdominal complaint is now appropriate.
The history of the present illness is a very valuable aspect to the acute abdomen assessment. OPQRST and SAMPLE can provide some of the most important information to your assessment. Last oral intake can be important in assessing new or unusual foods the person may have eaten, and the patient’s list of medications can provide information about preexisting GI problems. Asking some other questions, including evaluating any changes in bowel or bladder habits, any blood in the stool or vomit, and the overall color of recent bowel movements, can help clarify the possible problems the patient is experiencing.
Auscultation, observation, palpation, and percussion are the primary tools that will be used to assess the acute abdomen, in addition to a thorough verbal history of the present illness. By discussing the components of a thorough physical examination of the abdomen, these components can then be applied to any of the conditions described later. During the discussion on the specific pathologies that the paramedic may encounter, the assessment section of each will contain only abnormal findings associated with that pathology. It is understood and expected that the patient will receive a full assessment to rule out other possible conditions.

Auscultation
Although not often performed in the prehospital world, auscultating the abdomen should be performed, especially if the patient complains of diarrhea or not having had a bowel movement in several days. This should be done before palpating the abdomen because palpation may artificially increase the bowel sounds. Auscultation is done by placing the bell of the stethoscope anywhere on the abdomen, preferably over the lower quadrants, and listening for the presence or absence of bowel sounds. The absence of bowel sounds is most concerning because it may indicate paralysis of the bowel and severe constipation and obstruction.

Observation
Observe the surface of the abdomen and evaluate the skin and the shape of the abdomen while also being alert for bruising. The skin may have striae, which are stretch marks that can indicate a relatively rapid change in weight in a short period of time. This can be from fat, fluid, or pregnancy. The abdomen can be extremely large, called protuberant, most commonly from fluid buildup. Fluid in the abdomen is called ascites and happens most commonly from hepatic hypertension and results in an abdomen that is hard to the touch. Bruising may be found over the abdomen as well. The Cullen sign is bruising around the umbilicus and indicates intraperitoneal bleeding. This is a late sign of bleeding in the area. Bruising on 1 or both flanks indicates retroperitoneal bleeding and is called Grey Turner sign.

Tip: You can remember the Cullen sign and the Grey Turner sign with this little play on words. You can remember the Cullen sign with the made-up word: umbili-cullen. Remembering the Grey Turner sign becomes easier when you remember to “turner” the patient over to evaluate the flank!

Palpation
The abdomen is divided into 4 quadrants. The upper half of the abdomen lies superior to a horizontal line drawn at the level of the umbilicus, and the lower half is below that line. The abdomen is divided into right and left halves at the midline. When palpation is performed, ensure that all 4 quadrants are assessed. It is not uncommon to miss the lower quadrants because the provider is uneasy with getting too close to the genitalia. Missing the lower quadrants could mean missing issues such as an appendicitis or a large bowel obstruction. The following lists the contents of the abdomen found in each quadrant:

- Left Upper Quadrant (LUQ). Stomach, spleen, a portion of the transverse colon and the descending colon, and the tail of the pancreas
- Right Upper Quadrant (RUQ). Liver, gall bladder, head of the pancreas, and a portion of the transverse colon and the ascending colon
- Left Lower Quadrant (LLQ). Descending and sigmoid colon, small intestine, and left ovary (females)
- Right Lower Quadrant (RLQ). Appendix, ascending colon, small intestine, and right ovary

To palpate the abdomen, place the fingers of 1 hand over the flat fingers of the other and firmly depress about 2–4 inches posteriorly. This should not be painful to the patient with a normal abdomen. Note any rigidity, discomfort, or masses in the area depressed. Also note any muscular or physical guarding in the area. Muscular guarding occurs when the patient tenses the abdominal muscles over an area of the abdomen to prevent pain already in that area from being made worse; physical guarding is when the patient actually holds his or her hands or arms over the location for the same reason.
Palpate this way over all 4 quadrants, noting differences as they are found. In addition, if the patient has complained about abdominal pain in 1 or more quadrants, assess the most painful area last. Palpating the most painful area last will minimize the chance of the patient feeling pain in a larger area, which might happen if the painful quadrant is palpated first. Pain can be a sign of infection, bleeding, trauma, or obstruction.
Some special assessment points are to be evaluated during palpation. When palpating over the liver (RUQ) in the supine patient, observe the jugular veins as pressure is applied. If they engorge or become visible, it is possible the patient is fluid overloaded and narrowly avoiding going into pulmonary edema. This is a particularly important assessment point when providing any patient aggressive fluid resuscitation, especially those with a history of CHF. Also when palpating this area, the patient may complain of an increase in pain in his or her right shoulder. This could be referred pain often found with gall bladder problems.
As the abdomen is assessed, be alert for signs of rebound tenderness. When the hands are quickly pulled off the abdomen after applying light pressure, the abdominal wall briefly bounces. This bouncing of the abdominal wall is the rebound. If this causes the patient pain, the peritoneum, the membrane lining the cavity of the abdomen and covering the abdominal organs, is irritated either from blood or infection. Rebound tenderness, once discovered, should not be checked for again because it is extremely uncomfortable for the patient.

Percussion
Percussion is the least used assessment tool the paramedic can employ because it requires the greatest amount of practice and experience with normal to master. To percuss an area of the patient, in this case the abdomen, lay 1 hand over the area to be percussed. With the dominant hand, firmly tap the middle finger of the hand on the abdomen. Note the sound produced. A solid sound could indicate fluid or blood buildup in that area or it could be a normal finding if over 1 of the solid organs of the abdomen—the liver, spleen or pancreas. A hollow sound could indicate air, though it is a usual sound to hear during percussion of the abdomen.

Physiology, Assessment, and Treatment of Abdominal Problems

Gastrointestinal Bleeding
Gastrointestinal bleeding can be classified as upper GI or lower GI, depending on the location of the bleed. Generally speaking, upper GI is considered everything through the small intestine. Lower GI is the large intestine, rectum and anus. The appearance of blood from a GI bleed can present in any of 4 forms. First, the patient vomiting may vomit frank red blood, where the blood is vomited back up before it can be digested. This is called hematemesis. Second, if the blood has a chance to be digested before it irritates the stomach lining, the vomit will resemble coffee grounds, often with some undigested red blood still visible. Third, fully digested blood that is not removed via emesis will be excreted from the body in the stool. Stools containing fully digested blood are called melena and are sticky and very dark, almost black. Finally, lower GI bleeds will cause bloody diarrhea with red blood present and a smell unlike any other.

Upper GI Bleeds

Esophageal Varices
Esophageal varices are veins found in the inferior portion of the esophagus that are larger than normal. This occurs as a result of an increase in pressure in those veins, often the result of hepatic portal hypertension caused primarily by alcohol abuse or hepatitis C. Very often, the patient does not know he or she has this until one of them ruptures. Rapid bleeding from one of the veins usually results in hematemesis, frequently in copious amounts. Slower bleeds may result in coffee-ground vomit, and even slower bleeds may present with melena.
Prehospital treatment for esophageal varices is aimed at maintaining the person’s blood pressure and rapid transport. The patient may lose or have lost a large percentage of the circulating volume, resulting in hypotension and hypovolemia. Decreased hematocrit and hemoglobin also can result in reduced O2-carrying capacity plus signs and symptoms of shortness of breath or hypoxia. Patients should receive supplemental O2, even with saturations in the high 90s. Patients should at least have a saline lock started if they are normotensive and fluid run if there is even borderline hypotension. Because the vomiting is caused by stomach lining irritation secondary to the bleeding, antiemetic medications will not usually work and are generally not recommended in the case of bleeding.

Mallory-Weiss Syndrome
Mallory-Weiss syndrome is a tear in the junction between the esophagus and the stomach, often as a result of forceful, protracted vomiting. This tends to occur more in older adults but has been seen in pregnant women with severe hyperemesis gravidarum, commonly known as morning sickness. The condition can be life threatening. Bleeding with this condition is significantly less than with varices. Prehospital treatment includes treatment for hypotension because of dehydration from the protracted vomiting. Ondansetron may be given to attempt to minimize the vomiting and retching. Treatment for this condition involves rapid transport for surgical intervention at the hospital.

Gastroesophageal Reflux Disease
In gastroesophageal reflux disease (GERD), the cardiac sphincter, the circular muscle that separates the esophagus from the stomach, is not strong enough to prevent the flow of gastric contents superiorly. The patient will have a chronic complain of heartburn, especially after lying down. The continued effect results in distal esophageal bleeding because acid from the stomach erodes the esophagus. Bleeding can occur from the damaged, weaker areas of the esophagus. As with previous conditions, prehospital treatment is largely related to preservation of the blood pressure. GERD may be difficult to distinguish from ACS; when in doubt, obtain a 12-lead ECG and treat as if it is a heart problem.

Peptic Ulcer Disease
Peptic ulcer disease (PUD) is caused primarily by the bacteria Helicobacter pylori, which has the ability to survive the extremely acidic conditions in the stomach and overcome the lining of mucus that protects the stomach from digesting itself. Once the mucus layer is gone, the acid can now erode the stomach lining itself, causing bleeding and LUQ pain. This also can be caused by erosive gastritis, most commonly by excessive use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as acetaminophen, naproxen, and ibuprofen. Here again, erosion of the stomach lining causes pain and bleeding. Smoking and alcohol use can increase gastric acidity, worsening already existing ulcers.
Eating often mitigates the pain somewhat, only to return later after the food leaves the stomach, so asking about how the pain is before and after eating can help lead to a working diagnosis of PUD. If left untreated, the ulcer can bleed heavily, leading to hematemesis, coffee-ground vomit, and/or melena. Treatment for the paramedic is again focused on maintaining blood pressure if the patient is hypotensive or tachycardic.

Lower GI Bleeds

Hemorrhoids and Anal Fissures
Hemorrhoids are swelling and inflammation of the blood vessels surrounding the rectum. They can develop over time as a result of straining at stool, chronic constipation, or pregnancy. Irritation can cause them to rupture, and the bleeding can be quite profuse. Anal fissures are an actual tearing of the tissue in and around the anus. The causes for this are unknown, but anal intercourse or trying to pass large hard stools are believed to be the most common reasons. Patients seldom bleed heavily with either of these conditions, and treatment is therefore symptomatic. Only in rare cases will the bleeding be sufficient enough to cause a drop in blood pressure.

Inflammatory Conditions

Appendicitis
The appendix is a small tube-like structure at the proximal end of the cecum of the large intestine. Inflammation of the appendix can occur at any age and most often is the result of fecal matter blocking the lumen of the appendix. Once in there, the appendix is unable to flush out the fecal matter, and an infection begins. The bacteria and toxins irritate the lining of the appendix, and it begins to get inflamed. If left untreated, the appendix can burst, allowing bacteria and toxins to permeate the abdominal cavity. This will, in turn, irritate the peritoneum, leading to peritonitis. At this point, the profound infection can lead to sepsis and death.
Early on in appendicitis, the patient will present with periumbilical pain (pain in the area of the umbilicus), accompanied by a low-grade fever, nausea, and vomiting. As the infection and inflammation worsen, the periumbilical pain moves and centers over the LRQ and intensifies. If the appendix is not removed before this, rupture is likely. If the appendix has ruptured, the patient will actually report a transient decrease in pain; however, the pain the patient does have will be diffuse throughout the abdomen and be accompanied by rebound tenderness. When assessing these patients, repeated palpation over the area of the appendix could accelerate rupture, so care should be taken not to do this more than is needed to adequately assess the area.
Treatment for appendicitis involves treatment for shock if it is present. Establish an intravenous line and give fluid. Transport the patient in the position of maximal comfort, which may be on his or her left side with the knees drawn up. Drawing up the knees relieves tension in the abdominal wall and can substantially lessen any discomfort the patient would feel in other positions. If the patient is nauseous or vomiting, administer 4 mg ondansetron and consider analgesia.

Cholecystitis
Cholecystitis is the inflammation of the gall bladder. It may occur for a variety of reasons; however, little is known about why it occurs. Frequently, calcifications, called gall stones, occur within the gall bladder and block the outflow of the bile when it is needed. Bile is needed when fatty foods enter the duodenum to aid in the digestion of these fatty foods. If the gall stones block the duct leading to the small intestine, the patient will feel extreme pain when the gall bladder contracts to try and inject the bile into the small intestine.
The patient will complain of pain in the RUQ, often about 2–3 hours after a meal, especially if it is high in fat. The patient also may complain of nausea, vomiting, and fever and appear jaundiced. Treatment for this patient will center on getting the patient to the hospital; the patient will likely need gall bladder surgery. Analgesia seems like the humane thing to do during transport; however, morphine is believed to cause the sphincter of Oddi to contract, actually worsening pain. Meperidine is recommended in the case of cholecystitis, if it is available prehospital.

Diverticulitis
A diverticulum is essentially an aneurysm or a pouching of the wall of the digestive tract, usually of the large intestine. It is believed that these pouches form as a result of stools becoming harder. As they become harder, it becomes more difficult for the peristaltic movements of the colon wall to push the feces out. Consequently, pressure on the wall builds up with each contraction, and, eventually, a weak area gives way. In diverticulitis, this pouch (diverticulum) becomes inflamed, usually as a result of an infection, likely from trapped fecal matter that does not get moved out.
Patients will complain of pain, often in the LLQ, along with fever, malaise, and possibly vomiting. Patients can become septic very easily with diverticulitis. If the patient is septic, he or she may require large amounts of fluid to maintain blood pressure and may even require pressors such as dopamine. Patients will likely require surgery for the diverticulum and any adhesions that may have developed.

Pancreatitis
Inflammation of the pancreas is called pancreatitis and can be either chronic or acute. Acute pancreatitis is most commonly caused by gall stones and cholecystitis. The most common cause of chronic pancreatitis is heavy alcohol use. It causes intense, diffuse pain throughout the upper abdominal quadrants that is sometimes described as a burning pain that radiates to the back. Treatment for pancreatitis is largely symptomatic. Avoid morphine for the same reason as in cholecystitis.

Chronic Inflammatory Conditions
For the conditions in this section, prehospital treatment is the same: treat symptomatically and provide fluid if hypotensive. If the hypotension is refractory to fluid administration, consider pressors. Pain management for these patients should be nonnarcotic only to prevent opioid-induced constipation and an inadvertent worsening of the patient’s symptoms.

Crohn Disease
In Crohn disease, it is believed that the immune system attacks the GI tract, most commonly the area of the small intestine called the ileum. The ileum is the last 11 feet of the small intestine. It also has been proposed that genetics and heredity play a role. The disease may be present in the colon but only in certain areas in addition to or instead of the ileum. The patient also may have skin rashes and other extraintestinal symptoms, although these are not necessarily present in every patient. The patient often will present with LRQ abdominal pain with diarrhea that may be bloody if the disease is extensive and the ulcerations are actively bleeding.

Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is a chronic condition characterized by a hypersensitivity of colonic pain receptors. Normal degrees of stretch in these receptors, which people without this condition would not otherwise notice, is responded to with spasms in the colon of the patient with IBS. These spasms can be isolated, leading to bloating and constipation, or they may be wave-like and resemble peristalsis, leading to diarrhea and faster transit of stool through the colon. Patients will present with lower quadrant abdominal pain and either have not had a bowel movement recently or have had intractable diarrhea.

Ulcerative Colitis
Similar to Crohn disease in that it is an inflammatory bowel syndrome, ulcerative colitis (UC) is exclusively in the colon and does not have any systemic symptoms. In addition, Crohn disease affects the entire wall (transmural) of the colon and small intestine, whereas UC involves only the inner lining of the colon. As the lining gets ulcerated, the ulcers may start to bleed, leading to bloody stools and diarrhea. Infection also can be an issue in the ulcers, so the patient may have a fever, general malaise, and weakness. This is seldom a true emergency, and little can be done in the field to treat UC.

Obstructive Conditions

Small Bowel Obstruction
Small bowel obstruction (SBO) is any of a family of conditions that either narrow the diameter of the small intestine or prevent it from dilating when a larger amount of food moves through it. Postoperative adhesions, Crohn disease, cancer, and foreign bodies are the most common reasons for SBO. Patients will present with diffuse abdominal pain and often will be vomiting. The vomit or the patient’s breath may smell like feces caused by the back up of food at the point of the obstruction. Patients also may present with weakness, lethargy, and fever. Treatment is supportive until surgery at the hospital. Vomiting in this patient is therapeutic, so it should be allowed to happen; therefore, antiemetics are not recommended.

Large Bowel Obstruction
Large bowel obstructions can be caused by a mechanical obstruction or a constriction of the colon. The elderly are more susceptible to a mechanical obstruction because of an increased prevalence of cancer and diverticulitis in this age group. Meanwhile, the pediatric population can have a large bowel obstruction caused by intussusception or volvulus, both of which narrow the diameter of the large bowel. Intussusception is a condition where the bowel telescopes over itself, and volvulus is a twisting of the colon that causes a kink where fecal matter cannot pass. Presentation and treatment are similar to that of SBO.

Hernias
A hernia is when 1 organ pushes through a potential opening or ligament into a different body cavity. The 3 common types of hernias are hiatal, inguinal, and umbilical hernias. In a hiatal hernia, the stomach pushes superiorly through the diaphragm alongside the esophagus. More common in men, an inguinal hernia is where the small intestine pushes through the inguinal ligament and often can be felt inside the scrotum. Umbilical hernias tend to happen in the elderly or people who have had abdominal surgery; this is where part of the small intestine pushes through the abdominal wall and into the retroperitoneal space. A 4th, significantly less common hernia that can happen is called an incisional hernia. This is where typically abdominal contents push through the abdominal wall and either out of the body in extreme cases or into the retroperitoneal space; this is similar to a traumatic evisceration.
Hernias can be described as reducible, incarcerated, or strangulated. A reducible hernia is able to freely move back into its original anatomic position on its own or with manipulation. Incarcerated hernias, conversely, are trapped in their herniated position usually because the amount of intestine that has pushed through the opening is now larger than the opening, or the intra-abdominal pressure is high enough to keep it there. Strangulated hernias represent the only true surgical emergency of the 3 types. In a strangulated hernia, the blood supply to the portion of the organ that has herniated is diminished or occluded. This condition can lead to necrosis of that area of tissue in relatively short order if not relieved quickly.
Patients will present with varying amounts of pain, anywhere from an unusual feeling to extreme debilitating pain. The amount of pain, the location of the pain, and the radiation or referral of the pain is almost entirely caused by the size of the hernia and the degree of strangulation. SBO is possible in the presence of a hernia if the hernia appreciably decreases the lumen of the small intestine. Pain management and rapid transport in the position of comfort are the prehospital care goals.