An ALS ambulance responds to the report of abdominal pain. Upon arrival, the EMS crew finds a male in his mid-30s complaining of right lower quadrant discomfort. The patient, who is lying on his right side in a fetal position, says the pain started about two hours ago and he has never felt like this before.
Physical assessment reveals that the patient is conscious and oriented, with a heart rate of 110, sinus tachycardia, respiratory rate of 32 and blood pressure 132/70. He is able to speak in complete sentences and denies any cardiac or respiratory complaints. The patient says he had experienced a cramping sensation around his umbilicus earlier and the discomfort has become more constant. The discomfort appears to be sharp and localized to the lower right side of his abdomen. A head-to-toe assessment reveals that the patient has a tender right lower abdominal quadrant. The remainder of the assessment is unremarkable. No masses or signs of trauma are noted. The patient has no significant medical history and denies the use of drugs or alcohol, as well as nausea, vomiting or diarrhea.
Treatment is initiated with administration of supplemental oxygen and establishment of an intravenous line. During transport to the hospital, he remains on his right side with legs drawn in. He complains of lower right abdominal discomfort and is becoming nauseous. Vital signs are repeated as the crew arrives at the hospital.
The patient is evaluated by emergency department staff and is admitted for further assessment and evaluation. Following additional consultation and physical assessment, the patient is diagnosed with appendicitis and surgery is scheduled for the next morning.
Because EMS agencies respond to requests for assistance due to abdominal pain, providers should have a basic understanding of abdominal anatomy, as well as the conditions that can result in abdominal pain or discomfort. The following provides a general overview of abdominal pathology.
The abdomen is the largest cavity in the body. The abdominal wall is lined by the peritoneum, within which a majority of the abdominal organs are contained. Some organs, such as the kidneys, are retroperitoneal--located behind the peritoneum. The diaphragm separates the abdomen from the thorax. The abdominal wall is the anterior border, with the spine and back forming the posterior border. The lateral walls, or the sides, are the flank area which contains the kidneys. The epigastrium is the mid-upper abdominal area located just below the xiphoid process.1,2
To assist with abdominal organ location and landmarks, the abdominal region can be divided into quadrants by visualizing a median plane and a transverse plane that pass through the umbilicus at right angles and divide the abdomen into four quadrants: right upper quadrant (RUQ), right lower quadrant (RLQ), left lower quadrant (LLQ) and left upper quadrant (LUQ). Tables I and II provide an overview of the organs located within each quadrant. Figure 1 provides an example of the quadrants.1
Abdominal pain is a common complaint, accounting for up to 10% of emergency department visits. Abdominal pain can be associated with a variety of symptoms, including nausea, vomiting, fever, diarrhea, dark stools (melena) and urinary symptoms. A good history taken on a patient with abdominal pain should include the location, onset (sudden or gradual), intensity, quality (dull, sharp or cramping), progression and character (intermittent or constant) of the pain, as well as any associated symptoms. Aggravating or alleviating factors and previous episodes of similar pain should be considered. Past medical and surgical history, current medications and social history can be particularly helpful in patients presenting with abdominal pain. Populations that are particularly concerning when they present with abdominal pain include immunocompromised patients, the elderly and women of childbearing age, as these patients may be more likely to present with subtle findings on exam despite potentially devastating disease.
An acute abdomen is abdominal pain associated with findings on physical exam, such as guarding or rigidity, and generally implies that surgery will be required to manage the patient. Determining the exact cause of abdominal discomfort can be challenging, especially in the prehospital setting (see Table III). The following provides an overview of select causes of abdominal pain.3
Zachary Cope once said, "Acute appendicitis can mimic any intraabdominal process; therefore, to know acute appendicitis is to know well the diagnosis of acute abdominal pain."4 The appendix is a narrow tube attached to the colon. The lining of the appendix produces mucus that flows through the open center of the appendix and into the cecum. The wall of the appendix contains lymphatic tissue and a layer of muscle.5-7
Acute appendicitis develops when the appendix becomes inflamed as a result of obstruction of the lumen with subsequent bacterial invasion, distention and ultimately rupture. The incidence of appendicitis can be as high as 25% for males and 12% for females. Although appendicitis may occur at any age, adolescents and young adults account for a majority of the cases.5-7
The characteristic presentation of acute appendicitis is abdominal pain associated with anorexia, nausea and sometimes vomiting. The pain often begins in the periumbilical area and is described as vague and crampy. As the condition persists, the pain may become steady and sharp, localizing to the right lower quadrant.5-7
If the appendix ruptures, the patient may experience severe and diffuse abdominal pain, vomiting and a high-grade fever. Abdominal assessment may reveal a mass in the right lower quadrant that is tender to palpation, or signs of peritoneal irritation such as rebound, involuntary guarding and abdominal wall muscle spasms. Any movement of the patient (e.g., bumping the stretcher) may elicit severe pain. Patients may prefer to have their legs flexed and pulled up, similar to fetal position. If perforation occurs, hemodynamic compromise may develop.5-7 Depending on when in the course of appendicitis the patient is encountered, any number of presentations are possible, so always be aware of the possibility of appendicitis in virtually any patient complaining of abdominal pain.
The gallbladder is a pear-shaped organ that stores bile, which assists with digestion. The gallbladder is located in the upper right side of the abdomen, just below the liver. Gallbladder disease is a common problem, primarily because of the high prevalence of gallstones. About 25% of women and 15% of men over age 50 have gallstones, and more than one-half million cholecystectomies are performed every year in the United States.8-12
Biliary colic is the primary symptom of a majority of the patients who have gallstones and develop symptoms. The pain in biliary colic is most likely to occur when gallstones interrupt the normal flow of bile from the gallbladder into the bile ducts and down to the duodenum. The pain may initially develop in the epigastric area, or it may originate in the right upper quadrant of the abdomen. The pain may also extend under the right side of the rib cage. It is also possible for the pain to be poorly localized, and it may radiate to the right posterior shoulder. In rare cases, the pain may mimic that of substernal myocardial chest pain.8-12
The onset of pain tends to occur shortly after eating, especially meals that include fatty foods. Repeat episodes tend to involve a greater frequency and intensity of symptoms. Most episodes subside within a few hours; however, the patient may report abdominal aching that lasts for a few days following an episode of biliary colic. Nausea is often associated with biliary colic and vomiting may be present. Fever and chills are not common symptoms in uncomplicated biliary colic due to gallbladder stones.8-12
Acute cholecystitis occurs when there is a buildup of bile in the gallbladder. The accumulation of bile causes irritation and pressure in the gallbladder and can lead to inflammation, bacterial infection and perforation, any of which may cause pain. The primary cause of cholecystitis is gallstones. Other factors, such as alcohol abuse and tumors, can lead to gallstones as well. In general, cholecystitis tends to be more common in middle-aged women.8,13,14
There are two forms of cholecystitis: acute and chronic. Acute involves inflammation of the gallbladder that results in abdominal pain during a specific episode. Chronic cholecystitis involves inflammation of the gallbladder with a greater duration. Damage to the gallbladder can lead to a scarred and thickened organ, which can ultimately lead to inability of the gallbladder to store and release bile.8,13,14
The patient with cholecystitis may report having eaten a meal that included fried, greasy, spicy or fatty food. There is often acute, crampy pain in the right upper quadrant that tends to last more than six hours. The discomfort may also radiate to the right shoulder and may increase with inspiration. Murphy's sign refers to increased pain and interruption of inspiration during palpation of the right upper quadrant. The patient may experience fever, chills, nausea and vomiting, as well as symptoms similar to a myocardial infarction, such as epigastric discomfort that radiates to the shoulders.8,13,14
The large intestine is a tube-like structure that stores and eliminates waste material. As an individual ages, pressures within the colon result in bulging sacs in the wall of the bowel. When this out-pouching occurs in the bowel wall, it is called a diverticulum. When there is more than one bulging area, they are called diverticula. The presence of diverticula in the colon is referred to as diverticulosis.15,16
When a diverticulum becomes inflamed it is called diverticulitis. The patient with diverticulitis may have few or no symptoms. If they are present, symptoms may be vague and can include nausea, vomiting, diarrhea, chills and abdominal pain. The pain often begins in the hypogastric area (below the umbilicus) and then becomes more prominent in the lower left quadrant. The patient may develop a fever, tenderness over the left lower quadrant and rebound tenderness.15,16 Diverticulitis may result in perforation of a diverticulum or local abscess formation.
Intestinal obstruction can be caused by either mechanical or neurologic conditions and may occur within the small or large bowel. Mechanical causes include adhesions from previous surgeries, entrapment of intestine within a hernia, tumors, or twisting of the intestine. Neurologic causes are a result of alterations in peristaltic wave action of the intestinal wall. This results in backup of gas, secretions and intestinal contents. In either mechanical or neurological intestinal obstruction, the patient often experiences a crampy discomfort that is located in the periumbilical or suprapubic area. Abdominal distention, nausea and vomiting may result. Abdominal distention may result from the section of bowel that fills with intestinal contents.8,17
Other causes of intestinal obstruction include medication, intraperitoneal infection, impaired abdominal blood supply, kidney or thoracic disease, and metabolic abnormalities.8,17
The pancreas is a large gland located behind the stomach. It secretes enzymes through the pancreatic duct into the small intestine to assist in digestion of food and releases insulin and glucagons into the bloodstream. These hormones help the body to metabolize glucose from food.8,18
Pancreatitis is acute or chronic inflammation of the pancreas. In acute cases, onset tends to be rapid and may last for several days. Symptoms tend to develop quickly, with mild to severe upper abdominal pain often centered in the mid-epigastric area. The pain often radiates to the back and/or the chest, may be consistent for several hours, and may increase with eating or alcohol use. The patient may curl into fetal position or bend forward for relief. Symptoms will typically include nausea and vomiting. The patient's abdomen may be swollen and tender.8,18
Chronic pancreatitis generally develops gradually and can persist for years. These cases often develop as the result of continuous damage to the pancreas. In addition, the pancreas and surrounding tissue may sustain extensive damage before symptoms develop. Once symptoms occur, they are usually intermittent initially and become constant over time. The patient will often experience nausea, vomiting, fever and weight loss. Oily and malodorous stool may develop from poor digestion.8,18
Renal colic tends to involve flank pain that radiates to the abdomen and most frequently results from development of a renal stone or kidney stone. Nephrolithiasis, or kidney stones, affects more than 1 million people each year and accounts for approximately 1% of all hospital admissions. The overall incidence for males is approximately 12% versus less than 5% for females. Peak incidence occurs between ages 35 to 45.8,19
The pain in renal colic is caused by the dilation, stretching and spasm of the ureter caused by urethral obstruction from the stone. Pain is usually sudden in onset and severe. At onset there may be urgency to urinate. The patient may complain of pain originating in the flank area and radiating inferiorly and anteriorly to the lower quadrants or groin. Associated nausea, vomiting and blood in the urine are often reported, although hematuria is absent in more than 15% of cases. Patients with renal colic tend to move around constantly in an attempt to find a more comfortable position.8,19 The presentation of a patient with left-sided renal colic can be very similar to a patient with a thoracic aortic dissection or ruptured abdominal aortic aneurysm, so keep both entities in your differential diagnosis for flank pain radiating to the abdomen or groin.
ABDOMINAL AORTIC ANEURYSM
The abdominal aorta is a large blood vessel that originates at the heart and travels through the thorax into the abdomen. As the aorta travels through the chest, it is called the thoracic aorta. When it reaches the abdomen, it is called the abdominal aorta. The abdominal aorta supplies blood to the lower part of the body. Below the abdomen, the aorta splits into two branches that carry blood into each leg.20-22
An abdominal aortic aneurysm involves enlargement of the lining of the artery. When the lining becomes weak, the vessel wall thins and expands. If the aneurysm ruptures, the results can be devastating, with a fatality rate approaching 80%. A common location for an abdominal aortic aneurysm (AAA) is below the area that branches off to supply blood to the kidneys and above where it divides to supply blood to the pelvis and legs.20-22
An abdominal aortic aneurysm is most commonly found in males over age 60. It is estimated that more than 2% of the elderly population have aortic aneurysms. A pulsatile abdominal mass may be palpated just above the umbilicus. It is also possible for the pancreas or stomach to present as a similar mass, so the presence of an abdominal mass does not always equate to an AAA.20-22 However, if such a mass is noted, providers should suspect the presence of AAA until proven otherwise.
Patients with a leaking abdominal aortic aneurysm often complain of abdominal pain, abdominal rigidity, anxiety, nausea and vomiting, but can present with syncope and be otherwise asymptomatic. Groin pain, paralysis or flank pain may be the chief complaint. If the aneurysm ruptures, the patient may develop profound hemodynamic compromise.20-22
Assessment of the patient complaining of abdominal pain should begin before physical patient contact is made. For example, as you approach the patient, consider his overall appearance. Does he appear to be conscious? Is he complaining of abdominal pain or guarding his abdomen? Is the patient in a fetal position complaining of abdominal discomfort? What is his skin color: pink, pale, cyanotic, ashen or gray? Are there any clues on scene that reveal a possible cause, such as empty prescription bottles?
The chief complaint of abdominal pain can be vague, and there are numerous potential causes, some of which have been discussed. As a result, the provider must perform a thorough assessment. In some cases the patient may be able to provide a clear description and location of the pain; in other cases it may not be as straightforward. EMS providers should focus on performing a thorough assessment, forming an appropriate treatment plan, and determining the appropriate destination for the patient. Intervention should not be delayed in an effort to determine a diagnosis.
If possible, the assessment should include obtaining an accurate medical history. The history should be carefully considered, as it may suggest an etiology. The patient's history will also include private and potentially sensitive topics, and he/she should be assured that the detailed history is intended to promote optimal care and will not be shared with anyone other than healthcare providers who are directly involved in their care. If the patient is female, and depending upon available resources, providers may want to consider having a female healthcare provider available to assist in the history and physical exam.
Detailed history questions will vary depending upon the situation. Examples of questions to consider include: Has the patient had any recent abdominal surgery? If yes, what for? Were there any complications following surgery? Are there any reports of abdominal trauma? Has the patient experienced similar discomfort in the past? If yes, what relieved the symptoms? What events occurred (if any) prior to the onset of pain? What is the severity and duration of the discomfort? Has the discomfort remained consistent since onset or has it varied? Has anything relieved the discomfort? Has the patient taken any medications? Is there a report of alcohol or substance abuse? Has the patient experienced any nausea, vomiting or diarrhea? If the patient is female, could she be pregnant? Questions related to the menstrual cycle and pregnancy should be considered when interviewing any female of childbearing age who presents with abdominal pain.
An accurate and detailed history is also important because it may provide insight into the cause of discomfort. For example, a vascular event, such as rupture of an AAA, often involves a sudden, intense and excruciating pain. Pain that progresses from intermediate to severe over a short period of time may indicate appendicitis or acute cholecystitis. If the discomfort originates from a hollow organ, it may be described as a crampy sensation that is poorly localized. The patient may be unable to sit or lie still, and may appear to be in acute discomfort. In contrast, discomfort from a solid organ may be described as a more steady or constant discomfort. Patients with peritonitis (which typically results from an intra-abdominal inflammation like acute appendicitis) will typically want to lie still and avoid movement when possible.23
The patient exam will include observing the patient while conducting the physical assessment and incorporating their history. As patient assessment begins, observe (inspect) the abdomen for any bruising, asymmetry or other abnormality. The exam may include auscultation, palpation and tapping. Review your local protocols for abdominal assessment details, such as recommended technique and which components of the exam should be included. Table IV provides examples of assessment demonstrations that can be found on the Internet.
Depending on a variety of factors, such as the patient's level of distress, distance to the hospital and presence of potentially life-threatening conditions, auscultation may be considered. Auscultation can help to assess the activity of bowel sounds, which may be described as clicks and gurgles. If auscultation is going to be done, consider performing it prior to palpation.
Begin palpation with gentle and shallow pressure, then progress to deeper assessment. Gentle palpation is recommended first in an effort to reduce the chance that the patient will tighten his abdominal muscles. Palpate each quadrant while keeping possible organ and system involvement in mind. As palpation occurs, observe the patient for abdominal guarding, resistance or rebound tenderness.23
To assess for rebound tenderness, palpate the abdomen deeply and then quickly release the pressure. If the patient reports increased pain when pressure is released, he has rebound tenderness, which represents aggravation of the peritoneum and may indicate peritonitis.23
Obtain a complete set of vital signs early during the patient assessment. Vitals should include heart rate, respirations, blood pressure and temperature, when possible, and should be reassessed every 10 minutes, or more frequently as needed.23-25
Assessing for orthostatic vital sign changes, also referred to as postural changes, may be considered, especially if volume loss is suspected. To perform this, obtain an initial set of vital signs while the patient is either supine or sitting, then ask the patient to stand and retake his vital signs. Orthostatic changes can be noted by an increase in heart rate of approximately 20 beats or a decrease in blood pressure by up to 20 millimeters of mercury or more. Positive orthostatic changes may indicate volume depletion. A 20-10-20 rule may also be considered: a decrease in systolic blood pressure by 20, a rise in diastolic by 10, or an increase in heart rate by 20 beats per minute.23-25 Assessing for orthostatic vital signs is not recommended if the patient's initial vital signs reveal tachycardia and/or hypotension when sitting or supine.
Distal circulation and perfusion may be assessed to compare the color, texture and temperature of the legs. Check pedal or popliteal pulses for the presence of peripheral pulses.
Treatment should be guided by the patient's chief complaint, provider discretion and local protocols. In all cases, the patient's airway, breathing and circulation should be supported. Consider administering oxygen, especially in acute abdominal cases.
Because abdominal pain can cause varying levels of distress, the patient may experience extremes in comfort and positioning. Providers will need to ensure the patient's safety if he is unable to remain still while on the stretcher. This is especially important during transport or when the stretcher is being moved.
Intravenous access should be considered in most patients being transported for abdominal pain. This is especially the case if the patient is suspected to be suffering from a condition that may warrant aggressive fluid replacement and/or he is a possible surgical candidate. Intravenous fluid selection and flow rate should be determined in part based on the patient's overall condition. Obtain prehospital blood samples in accordance with local protocols. If available, obtain a dextrose reading.23,25
Depending upon the EMS system's protocols, consider medication to relieve symptoms. For example, fentanyl may be administered for abdominal pain in the prehospital setting.26-28 This offers the benefits of rapid onset and potency, with an onset of relief that is noted to be quicker than morphine sulfate. Administration of fentanyl also tends to be associated with fewer hemodynamic effects or hypotension versus other similar medications. While respiratory depression may be encountered, it is less likely than with morphine.26-28 Muscle spasm or pain control may also be treated by other medications, such as benzodiazepines. If the patient is experiencing vomiting, consider an anti-emetic.29
A combination of medications may be helpful in managing numerous symptoms. For example, giving metoclopramide (Reglan) to patients receiving opioids for pain may reduce the incidence of nausea and vomiting.30 Promethazine hydrochloride, or Phenergan, is an anti-emetic that can also be used in the field; however, providers should monitor the patient for side effects like drowsiness, hypotension, dystonic reaction and dysrhythmia. Providers are encouraged to consult with their local protocols regarding the use of these or any medications in the setting of acute abdominal discomfort.31
Transport the patient to an appropriate receiving facility. In the event he refuses transport, inform him of the possible consequences ranging from complications to the risk of death. Discussions like these should be carefully documented in accordance with local protocol.
Because EMS providers are likely to encounter patients with abdominal pain, having a basic understanding of its causes is an important component in providing adequate care. The ability to obtain a thorough history and perform a detailed assessment is key to the overall management of the patient complaining of abdominal pain.
1. Spence A, Mason E. Human Anatomy and Physiology, 3rd Ed. Menlo Park: The Benjamin/Cummings Publishing Company Inc., 1987.
30. Smith E, Wasiak J, Boyle M. Prophylactic metoclopramide for opioid induced nausea and vomiting following treatment of acute pain in the prehospital setting. Journal of Emergency Primary Health Care, 2 (1-2), 2004.
Paul Murphy, MA, MSHA, is a paramedic with administrative and clinical experience in healthcare organizations.
Chris Colwell, MD, is medical director for Denver Paramedics and the Denver Fire Department, as well as an attending physician in the emergency department at the Denver (CO) Health Medical Center.
Gilbert Pineda, MD, FACEP, is medical director for the Aurora Fire Department and Rural/Metro Ambulance (Aurora, CO) and an attending physician in the emergency department at The Medical Center of Aurora and Denver Health Medical Center.
Tamara Bryan, BS, EMT-P, has more than a decade of healthcare experience, including clinical and project management roles. She is currently pursuing her Physician Assistant credentials.