Abdominal Pain, Non-Traumatic

The relatively common, serious, high yield diagnoses which present as non-traumatic abdominal pain (AP) are: appendicitis, bowel ischemia, intestinal perforation, ruptured/leaking aneurysm, bowel obstruction, and ruptured ectopic pregnancy.

As with chest pain, in the process of ruling these diagnoses out many other conditions may be discovered. Some of these are also serious and may need immediate treatment. Nonetheless, one of the commonest ED diagnoses after evaluating AP is “abdominal pain of uncertain etiology”. This is a perfectly legitimate diagnosis. It implies that while no specific cause has been uncovered that immediate threats to life or well being are effectively ruled out.

In prior generations, the primary question a clinician was trying to answer when evaluating an AP patient was “is this an acute abdomen”. Phrased differently, this was a way of asking “does this patient need to go right to the operating room or at least need urgent evaluation by a surgeon?” In the 21st century, very few patients even with traumatic abdominal pain are taken directly to OR. Thus in most cases, the question clinicians need to answer in an AP patient has become “what testing does this patient need”. But the acute surgical abdomen still exists and immediate surgical consultation is sometimes required.

The Acute (Surgical) Abdomen
Even now, in the 21st century, there are still patients needing urgent surgical evaluation/treatment prior to sophisticated imaging, lab tests, etc. IOW they are clinically found have an acute abdomen (ACA).

The typical ACA patient has the sudden onset of severe abdominal pain. When this is combined with a physical exam showing signs of peritonitis, urgent surgical evaluation is indicated. A “complete” set of labs with type and screen/cross and a lactate level are indicated.

It is good practice to pre-notify the consultant if you have a reasonable suspicion of this diagnosis

The Non-Acute Abdomen
When the clinical scenario is not consistent with an ACA, urgent consultation is not needed. The primary decision then becomes: which patients need testing or imaging versus those that can be managed clinically?

Gastroenteritis
The commonest abdominal pain patient who can be managed clinically is one with acute gastroenteritis (AGE). While often triaged as “abdominal pain”, this is usually a secondary complaint or is co-equal with nausea, vomiting, and diarrhea. There are often systemic complaints such as fever, chills, malaise, myalgias, etc.

The work-up of a patient with clinical AGE should proceed as follows.

Patients with AGE may become quite ill appearing if they are sufficiently dehydrated. It’s hard to avoid the urge to order lab tests in a patient with clinically apparent AGE when there are significantly tachycardic or at times even hypotensive. Lab abnormalities in this setting are common.

AGE is much more common in younger patients. Be more inclusive in the DDx and get labs in the very old or very young when the symptoms are severe or the VS abnormal.

Treatment of AGE (easy and gratifying): Replace fluid losses with normal saline. Treat symptoms when present as follows.

“Dr. Krause’s AGE cocktail” is as follows.

Patients may be discharged when they feel better, and they often feel a LOT better.

Vital sign abnormalities should be pretty much normalized prior to DC.

IF you sent labs which showed abnormalities you may need to repeat them and show them going in the right direction prior to DC.

Imaging for AGE? NO

Admission for AGE?

Appendicitis/RLQ pain
In the old days, appendicitis was a clinical diagnosis and considered an “acute abdomen”. This has changed, somewhat for the better. Surgeons were traditionally taught that they should be removing at least 10% normal appendices. The implication was that if they raised the bar for surgery so high that less than 10% of the removed organs were normal they would probably be delaying the diagnoses (“missing”) in too many cases. Many fewer normal appendices are removed and fewer cases missed since CT scanning for RLQ pain has come into vogue.

The suggested paradigm when considering possible appendicitis in the present day is as follows. Try to clinically (based solely on H+PE) classify patients as: Definite appendicitis, Possible appendicitis, Not appendicitis.

Definite appendicitis:

Management is to get belly labs and have an EM to surgery attending dialogue

Possible appendicitis:

Management:

Not appendicitis: Pursue other diagnosis

Biliary Disease/RUQ pain
RUQ pain is usually of biliary origin. There is a continuum from asymptomatic gallstones to biliary colic and on to cholecystitis, gangrene of the gallbladder, cholangitis, billiary sepsis, etc. Patients with the latter mentioned more serious diseases present with signs and symptoms of systemic toxicity and not simply RUQ pain.

When the H+PE suggest acute biliary disease, ultrasound is often indicated. Before answering the question of when to order or perform US or other testing I will discuss RUQ pain that is not biliary. The main things to consider besides biliary disease are pathology above the diaphragm and appendicitis in an atypical location.

PE and pneumonia are diseases above the diaphragm that may present as RUQ pain. The H+PE are the key to suspecting them. For both conditions there should not be RUQ tenderness or a Murphy’s sign. This can be a little misleading as either pneumonia or PE may cause pleural irritation and inspiratory pain or arrest when the RUQ is palpated.

Right sided abdominal pain should always raise the question of appendicitis.

Pain and tenderness in acute billiary disease usually corresponds to the location of the gallbladder-tucked up under the liver and usually palpated just below the costal margin unless the liver is enlarged.

What patients with suspected acute biliary disease do not need imaging in the ED?

There is fairly good evidence that Toradol (or other NSAIDs) may be particularly effective in biliary colic.

Biliary colic may be one of the few remaining indications for meperidine (Demerol) but many hospitals have removed it from formulary. Demerol has significant adverse effects when given in large, repeated doses but is acceptable for single use.

What about lab tests in biliary colic? They are not needed in theory but almost always performed. If performed, expect normal results

How is more serious biliary disease such as acute cholecystitis differentiated from biliary colic? Again, there is a continuum that proceeds as follows: asymptomatic gallstones→biliary colic→acute cholecystitis→biliary sepsis, gangrenous gallbladder, cholangitis, gallstone pancreatitis, etc. There is no hard and fast line between biliary colic and cholecystitis in particular. Besides direct visualization or pathologic examination, the gold standard for diagnosis of acute cholecystitis (ACC) is probably nuclear (HIDA) scanning. The sensitivity is in the range of 98%. However, ultrasound is more available, quicker, and involves no radiation. The sensitivity of US is ~90%. So the question to be answered first is:
When should ACC be suspected and lab and imaging tests ordered?

What imaging is indicated? The test of choice is ultrasound.

Findings on US that suggest ACC:

Treatment of ACC

Complications of ACC includes the conditions noted above and will be discovered in the course of working up ACC.

CAT scanning in biliary disease

Epigastric/Periumbilical Pain
The main entities to be considered are referred pain, acid/peptic diseases, pancreatitis, and vascular catastrophes. Gallbladder disease may also present as more mid than right sided. 

Referred Pain to the Epigastrium

However, EKG and a troponin are convenient and low cost, so you should consider them in patients with cardiac risks or when your gestalt tells you to.

Acid/Peptic Disease
These include gastritis, ulcer, GERD/esophagitis. Patients with these conditions may usually be treated as outpatients. Definitive diagnosis is by endoscopy, this is not usually available in the ED and the diagnosis is therefore clinical. Empiric treatment with a PPI is often appropriate 

GERD/Esophagitis: More often presents as chest pain and is dealt with in that essay.

Ulcer/Gastritis: The symptoms of ulcer and gastritis overlap and both often present as epigastric pain. Provided serious complications are not present clinical diagnosis and empiric treatment are appropriate. The symptoms are:

The PE should be essentially normal. The may be minor epigastric tenderness for reasons that are not well understood. Obviously, there should be no masses or peritoneal signs.

Perform a rectal exam: The purpose is to rule out serious GI bleeding. If the stool is black, maroon, or strongly guaiac positive place an NG tube to evaluate possible serious UGI bleed. If rectal exam produces brown stool and guaiac testing is negative or weakly positive and the patient is otherwise stable with no signs/symptoms of acute bleeding an NG tube is not needed.

Lab tests: Not needed when the H+PE are consistent with ulcer/gastritis and no other serious condition remains in the differential.

If there is significant epigastric tenderness, especially in a drinker and when there is nausea/vomiting consider pancreatitis and order lipase

Disposition/Treatment of acid/peptic UGI disease

Abdominal Vascular Catastrophe
Ruptured or leaking AAA often presents as upper abdominal pain. Keep in mind that the aorta is also a thoracic organ and diseases of the aorta may span the two compartments. Ruptured or leaking AAA usually presents as severe upper or mid abdominal pain with radiation to the mid or lower back. The pain may be felt entirely in the back.

If a pulsatile mass is found on exam in a patient with the above symptoms or if ruptured AAA is still in your gestalt even w/o a mass regard the case as “ruptured AAA until proven otherwise.”

Imaging for AAA
Do not delay surgical consultation for suspected ruptured AAA while waiting for imaging
Notify the surgeon and coordinate imaging with them

Acute Pancreatitis
Acute pancreatitis (AP) in the ED population is usually associated with alcohol abuse. The second most common cause is a gallstone causing obstruction or edema/dysfunction of the ampulla. Other causes are less common and include severe hypertriglyceridemia, infections, hyperkalemia, etc. Post-ERCP pancreatitis is seen frequently.

The signs and symptoms of acute pancreatitis are:

What lab tests should be ordered in cases of suspected acute pancreatitis?

Imaging in acute pancreatitis.

Treatment/Disposition in pancreatitis

ED treatment is as follows:

Periumbilical/Poorly Localized Abdominal Pain/Mid-Abdominal Pain
Besides generalized peritonitis (dealt with separately in this essay) the main emergencies to consider in mid abdominal or poorly localized abdominal pain is intestinal ischemia and bowel obstruction.

Small Bowel Obstruction

Imaging in suspected SBO
An “abdominal series” with flat and upright abdominal films and an upright chest x-ray should usually be ordered in cases of suspected SBO.

According to the American College of Radiology Appropriateness Criteria oral contrast should not be used. In cases of suspected acute, high grade SBO.

When plain films reveal SBO, CT scanning is not necessary in the ED and patients should not be held there waiting for further imaging.

Lab tests in SBO

ED treatment of SBO

Large Bowel Obstruction
Colonic obstruction (LBO) is less common than SBO. The causes differ and pseudo-obstruction occurs frequently in certain groups. Clinically, though differing in many details, it also presents as distention, nausea, and vomiting along with inability to pass flatus and stool.

Intestinal Ischemia
Mesenteric ischemia can be caused by either arterial or venous obstruction. Arterial obstruction may be caused by embolism or thrombosis. Ischemia may also occur due to mesenteric venous thrombosis. The more common ED presentation is due to mesenteric arterial obstruction.

Risk factors for mesenteric ischemia include:

Lab tests in suspected acute mesenteric ischemia

Imaging in suspected acute mesenteric ischemia

Consultation/disposition in suspected acute mesenteric ischemia

Left-sided Abdominal Pain
Diverticulitis is the primary consideration in left sided abdominal pain. Usually the pain and tenderness of diverticulitis is localized to the LLQ. But in some cases the pain is located higher up and right sided diverticulitis does (rarely) occur. When pain is truly in the left upper quadrant, consider causes above the diaphragm and if none of those seem to fit give consideration to oddballs like splenic infarction or abscess. Also, in the right circumstances, consider the same entities which cause epigastric pain. Luckily, CT scanning will reveal most of the important causes in addition to diverticulitis if it happens to present in this atypical location.

Lab tests in suspected diverticulitis

Imaging in suspected diverticulitis

Disposition of patients with diverticulitis

ED treatment of diverticulitis

Abdominal Pain in the Elderly will be discussed in a separate essay

Pelvic/Suprapubic Pain to be addressed in a separate essay.

Pediatric Abdominal Pain will also be discussed separately. But one thing I want to mention here is testicular torsion. This is usually a disease of adolescents. But in any age group will occasionally appear as "abdominal pain". Especially when no abdominal cause is found in a younger male patient: DO A GU EXAM WITH ATTENTION TO THE SCROTAL CONTENTS!