Laboratory studies Complete blood count
A complete blood count (CBC) is frequently ordered in patients with abdominal pain. Despite the association of an elevated white blood cell (WBC) count with many infectious and inflamma- tory processes, numerous studies have demon- strated that many patients with surgically-proven appendicitis have initially normal WBC counts.
Even serial WBC counts have failed to discrimin- ate between surgical and nonsurgical illness. In the patient with abdominal pain, an elevated WBC does not necessarily imply serious disease, detect- ing only 53% of patients with severe abdominal pathology in one study. In fact, elevations of the WBC count may lead to additional tests and increased costs without providing additional infor- mation. The CBC should never be used to make the sole diagnosis of abdominal pathology, nor should it be used in isolation to exclude reasonable diagnostic possibilities. The bottom line is that decision-making in cases of abdominal pain rest primarily on a carefully taken history and thor- ough physical examination, not the WBC count.
Urinalysis
The urinalysis is a rapid, cost-effective adjunctive laboratory test that needs to be interpreted with caution in patients with abdominal pain. Findings suggestive of UTI include pyuria, positive leuko- cyte esterase, positive nitrites and the presence of bacteria. However, up to 30% of patients with appendicitis may present with blood, leukocytes or even bacteria in their urine. A mild degree of pyuria may be present in elderly patients at base- line. Be wary of ascribing abdominal pain to a UTI when the clinical picture does not fit. Red blood cells (RBCs) in the urine are consistent with infec- tion, trauma, tumors and stones. The patient with acute flank pain and hematuria suggests renal colic but also may represent a leaking or ruptured AAA.
Pregnancy test
All female patients of childbearing age with abdominal pain should have a pregnancy test.
A positive pregnancy test expands the differential diagnosis (i.e., ectopic pregnancy), influences the choice of medications or adjunctive studies, and may impact disposition. Do not omit pregnancy
testing in patients who report sexual abstinence, tubal ligation or contraceptive use.
Amylase/lipase
Though a serum amylase is commonly ordered when looking for pancreatitis, it may be normal in as many as a third of patients with pancreatitis.
The serum amylase may also be elevated in other conditions including peptic ulcer or liver disease, SBO, common duct stones, bowel infarction, ectopic pregnancy, ethanol intoxication and dia- betic ketoacidosis (DKA). Serum lipase has a higher sensitivity and specificity for pancreatitis than total amylase, and is therefore the most use- ful test in a patient with suspected pancreatitis.
Other laboratories
Liver function tests may be elevated in patients with biliary or hepatic disease. Serum electrolytes may be abnormal in patients with significant vomiting or diarrhea, symptoms24 hours dura- tion, diuretic use, or a history of kidney or liver disease. Serum phosphate and serum lactate may be elevated in cases of bowel ischemia.
Electrocardiogram
Electrocardiograms (ECGs) should be considered for all patients with unexplained epigastric or abdominal pain. They are particularly essential in the evaluation of elderly patients with vague, poorly localized abdominal complaints. An acute coronary syndrome (ACS) or inferior MI can present with epigastric pain, diaphoresis and vomiting. Though a normal ECG in the setting of abdominal pain does not exclude an MI, it makes it less likely.
Radiologic studies Plain films
Abdominal plain films are markedly overutilized, difficult to interpret (even in experienced hands), and rarely provide useful clinical information.
Plain films are unlikely to be helpful in patients with nonspecific abdominal pain, suspected appendicitis, and UTIs. In fact, they may cloud the diagnosis leading to delays in management.
Plain films of the abdomen should be restricted to patients with suspected bowel obstruction,
Abdominal pain
perforated viscus or foreign bodies. Even in these presentations, computed tomography (CT) scan- ning provides much more detailed information.
When evaluating plain abdominal radiographs, look for abnormalities such as dilated loops of large or small bowel, air-fluid levels, abnormal calcifications of the abdominal aorta or urinary tract, gallstones, and free air under the diaphragm (Figure 9.6).
Ultrasound
Ultrasound has emerged as an extremely useful diagnostic modality in patients with abdominal pain. Advantages of ultrasound include lack of ionizing radiation, low cost and widespread avail- ability. It is the preferred imaging approach for evaluating patients with RUQ pain. In patients with acute cholecystitis, ultrasound may detect gallstones, gallbladder wall thickening, perichole- cystic fluid or a sonographic Murphy’s sign.
Ultrasound is also commonly used to make the diagnosis of acute appendicitis, particularly in children, thin adults, women of reproductive age and pregnant patients. The primary sonographic
criterion of appendicitis is demonstration of a swollen, noncompressible appendix7 mm in diameter with a target configuration (Figure 9.7).
Figure 9.6
Pneumoperitoneum. AP erect chest X-ray reveals free air beneath the left hemidiaphragm consistent with pneumoperitoneum.
Figure 9.7
Appendicitis on ultrasound. Gray scale longitudinal ultrasound demonstrates enlarged non-compressible appendix (cursors) 7 mm, consistent with acute appendicitis.Courtesy: GM Garmel, MD.
Abdominal pain Additionally, ultrasound is useful in imaging the pelvic organs; the transvaginal approach is preferred and superior to the transabdominal approach for the diagnosis of ectopic pregnancy.
Limited bedside ED ultrasonography can be used for:
1. confirming an intrauterine pregnancy which dramatically lowers the risk of ectopic pregnancy;
2. screening for the presence of a AAA (Figure 9.8);
3. screening for the presence of free intraperitoneal blood in patients with abdominal trauma (see Appendix E).
Ultrasound may be difficult to perform in obese patients and those in severe pain. As ultrasound requires considerable skill, findings are operator- dependent and interpretation errors can occur.
A negative ultrasound does not exclude the diag- nosis of either appendicitis or ectopic pregnancy.
Abdominal computed tomography
Abdominal CT has fast become the modality of choice in patients with undifferentiated abdominal pain who require imaging, as it allows for a panorama-like visualization of the structures of the peritoneal and retroperitoneal space, unin- hibited by the presence of bowel gas or fat. Due to its exceptional accuracy, CT is often the pri- mary imaging modality in patients with sus- pected appendicitis. CT findings of appendicitis
(Figure 9.9) include a swollen, fluid-filled appen- dix often with a calcified appendicolith or inflam- matory changes in the periappendiceal mesenteric fat. After perforation, a phlegmon or abscess may be visible. CT is also useful for determining the diagnosis (and in many cases, the clinical severity) of conditions such as renal colic, bowel obstruc- tion, bowel perforation, bowel ischemia, diverti- culitis, pancreatitis, intra-abdominal abscess and AAA. The major drawbacks of CT are the cost, radiation dose and availability.
General treatment principles
As with all ED patients, treatment begins with the ABCs (Airway, Breathing, Circulation). The main goals of treatment are physiologic stabilization, symptom relief and preparation for surgical inter- vention when warranted.
Volume repletion
Not all patients with abdominal pain need intra- venous (IV) access or IV fluids. However, many patients have some degree of volume contraction resulting from poor intake, vomiting and diar- rhea, or third-spacing. Other patients may have volume loss secondary to internal bleeding (e.g., ectopic pregnancy). Crystalloids are the initial fluids of choice in both children and adults. The rate of repletion is determined by the degree of Figure 9.8
Ruptured abdominal aortic aneurysm (AAA) on
transverse color Doppler sonogram. Note color flow within aneurysm (A) and retroperitoneal clot and hemorrhage posterior to AAA (arrows).Courtesy: R. Brooke Jeffrey, MD.
Figure 9.9
Acute appendicitis on contrast enhanced CT. Note enlarged appendix with multiple appendicoliths.
Periappendiceal fat stranding is apparent.Courtesy: R. Brooke Jeffrey, MD.
Abdominal pain hypovolemia, the cardiovascular status of the
patient, and the response of the patient to initial therapy. Under certain circumstances, such as life-threatening hemodynamic collapse, blood products may be the initial resuscitation fluid.
Pain relief
Despite the long held opinion that narcotic anal- gesia masks peritoneal signs of an acute abdomen, there is no clear evidence supporting this notion.
In fact, recent studies have revealed that the administration of moderate doses of analgesia and the ensuing pain relief do not cloud diagnos- tic findings; instead, this approach actually may aid in the diagnosis of surgical disease. In the acute setting, pain relief is typically achieved with IV titration of opioid analgesics such as morphine sulfate or fentanyl.
When combined with narcotic agents, IV ketorolac provides pain relief for patients with bil- iary and renal colic. Patients with epigastric dis- comfort may gain relief from a GI cocktail (varied combinations of an antacid, viscous lidocaine and/or donnatal). Though the GI cocktail may be therapeutic, it is not diagnostic, as even pain from an acute MI may be relieved by this therapy.
Antibiotics
Antibiotics are indicated in patients with abdom- inal sepsis, suspected perforation, or the pres- ence of peritonitis (local or diffuse). Abdominal infections are often polymicrobial and necessi- tate coverage for enteric Gram-negatives, Gram- positives, and anaerobic bacteria. The specific regimen must take into account the patient’s pres- entation, comorbid conditions, and local bacterial drug sensitivities and drug-resistance patterns.
Other
The control of emesis can be achieved by a num- ber of agents. Patients in whom surgery is antici- pated should be kept from eating or drinking (NPO). A nasogastric (NG) tube may be of benefit in patients with vomiting refractory to antiemetic administration or confirmed bowel obstruction.
Special patients
Elderly
Several factors make the diagnosis and manage- ment of abdominal pain in elderly patients chal- lenging. Surgical causes of abdominal pain
increase in incidence with advancing age, whereas nonspecific abdominal pain becomes less com- mon. Typically, surgical illness in elderly patients is more rapidly life-threatening than in younger patients. Older patients are at much greater risk for vascular catastrophes such as ruptured AAA, mesenteric ischemia and MI. Elderly patients are more likely to present without the classic or expected historical or physical examination find- ings associated with a common disease. Because of atypical presentations and comorbidities, patient mortality and rates of misdiagnosis increase expo- nentially each decade after age 50. This highlights the importance of considering surgical illness (and surgical consultation) in most elderly patients with abdominal pain. About 40% of all patients65 years of age presenting to the ED with abdominal pain ultimately require surgery.
Pediatric
The diagnosis of abdominal pain in children presents its own unique challenges. Histories must often be obtained from the children and caregivers. Children are not always able to articu- late their complaint or describe their symptoms.
Consequently, younger children tend to present with late symptoms of disease and have a higher incidence of perforated appendicitis compared to adults. The usual etiologies of abdominal pain in children vary from those in adults (Table 9.3).
Gastroenteritis, non specific abdominal pain and appendicitis are more common in children, whereas biliary disease, pancreatitis and vascu- lar disease are relatively rare. Illnesses relatively unique to children include intussusception, volvu- lus, pyloric stenosis and Hirschsprung’s disease.
Any child presenting with bilious vomiting should be presumed to have a bowel obstruction.
Immune compromised
In addition to ordinary afflictions such as appen- dicitis, patients with human immunodeficiency virus (HIV) presenting with abdominal pain may also have:
1. enterocolitis with profuse diarrhea and dehydration;
2. large bowel perforation associated with cytomegalovirus (CMV);
3. bowel obstruction from Kaposi’s sarcoma, lymphoma or atypical mycobacteria;
4. biliary tract disease from cryptosporidium or CMV;
5. drug-induced pancreatitis.
Abdominal pain
The use of antibiotics, steroids or other immunosuppressants may mask abdominal exam- ination findings usually associated with infec- tion, so consideration should be given to any abdominal pain complaint, no matter how slight.
Steroid use can lead to demargination of leuko- cytes, making interpretation of the WBC count more difficult. Steroids also promote peptic ulcer disease, leading to an increased incidence of per- forated viscus.
Disposition
Surgical consultation
Patients with an acute abdomen or confirmed sur- gical illness require urgent surgical consultation.
Life-threatening diagnoses such as ruptured AAA or ectopic pregnancy require emergent con- sultation and expedited treatment. The most com- mon causes of abdominal pain requiring surgical consultation are appendicitis, intestinal obstruc- tion, perforated ulcer and acute cholecystitis.
These patients should be kept well-hydrated and NPO. Early diagnosis and surgery for appendici- tis prevents perforation and the associated acute (abscess formation, sepsis) and late (scar forma- tion with bowel obstruction/infertility) compli- cations.
Serial evaluation
Observation with serial examinations allows the emergency physician an extended evaluation of a patient with an early or atypical presentation of appendicitis or another acute abdominal process.
These patients are kept in the ED or admitted to the hospital for serial abdominal examinations.
Serial evaluation, preferably by the same phys- ician, allows a patient’s clinical picture to evolve or resolve over a period of time. Studies have shown that observation and repeated examinations of patients with suspected appendicitis improve diagnostic accuracy without increasing rates of perforation.
Discharge
After a thorough work-up in the ED or serial observation, patients without evidence of concern- ing medical or surgical illness may be discharged.
Despite a patient’s expectation of a firm diagnosis, it is perfectly acceptable to diagnose the patient with nonspecific or undifferentiated abdominal pain. In fact, the majority of patients are dis- charged from the ED with this diagnosis. Avoid forcing a diagnosis on the patient such as acute gastroenteritis. True gastroenteritis requires the presence of vomiting and diarrhea.
When discharging a patient with undiag- nosed abdominal pain, it is important to arrange for a repeat evaluation within 8–10 hours (either in the ED or with an outpatient clinic) and make it clear to the patient to return to the ED if symp- toms worsen. Typically, patients are placed on a clear liquid diet and narcotic analgesics are avoided. For patients returning to the ED with worsening symptoms, the additional opportunity to establish the diagnosis should be welcomed.
Typically, these patients are more likely to have appendicitis or bowel obstruction. Patients in whom reliable follow-up cannot be arranged or assured may require admission.
Birth to 1 year 2–5 years 6–11 years 12–18 years
Constipation Appendicitis Appendicitis Appendicitis
Gastroenteritis Constipation Constipation Constipation
Hirschsprung’s disease Gastroenteritis Functional pain Dysmenorrhea Incarcerated hernia Henoch–Schönlein Gastroenteritis Ectopic pregnancy Infantile colic purpura Henoch–Schönlein purpura Gastroenteritis Intussuception Intussuception Mesenteric lymphadenitis Mittelschmerz
UTI Pharyngitis Pharyngitis Ovarian torsion
Volvulus Sickle cell crisis Pneumonia PID
Trauma Sickle cell crisis Testicular torsion
UTI Trauma Threatened abortion
Volvulus UTI
PID: pelvic inflammatory disease; UTI: urinary tract infection.
Adapted from Leung AKC, Sigalet DL. Acute abdominal pain in children.Am Fam Physician2000;67(11).
Table 9.3 Causes of abdominal pain by age of onset
Abdominal pain
Pearls, pitfalls, and myths
• Do not restrict the diagnosis solely by the location of the pain.
• Consider appendicitis in all patients with abdominal pain and an appendix, especially in patients with the presumed diagnosis of gastroenteritis, PID or UTI.
• Do not use the presence or absence of fever to distinguish between surgical and medical causes of abdominal pain.
• The WBC count is of little clinical value in the patient with possible appendicitis.
• Any woman with childbearing potential and abdominal pain has an ectopic pregnancy until her pregnancy test comes back negative.
• Pain medications reduce pain and suffering without compromising diagnostic accuracy.
• An elderly patient with abdominal pain has a high likelihood of surgical disease.
• Obtain an ECG in elderly patients and those with cardiac risk factors presenting with abdominal pain.
• A patient with appendicitis by history and physical examination does not need a CT scan to confirm the diagnosis; they need an operation.
• The use of abdominal ultrasound or CT may help evaluate patients over the age of 50 with unexplained abdominal or flank pain for the presence of AAA.
References
1. American College of Emergency Physicians (ACEP). Clinical policy. Critical issues for the initial evaluation and management of patients presenting with a chief complaint of nontraumatic acute abdominal pain. Ann Emerg Med2000;36(4).
2. Coluciello SA, Lukens TW, Morgan DL.
Assessing abdominal pain in adults: a rational, cost-effective evidence based approach. Emerg Med Prac1995;1(1).
3. DeGennaro BA, Jacobsen SJ. Abdominal pain. In: Harwood-Nuss A (ed.). The Clinical Practice of Emergency Medicine, 3rd ed., Philadephia: Lippincott Williams &
Wilkins, 2001.
4. Gallagher EJ. Acute abdominal pain. In:
Tintinalli JE (ed.).Emergency Medicine: A Comprehensive Study Guide, 5th ed., McGraw Hill, 2000.
5. Graff LG, Robinson D. Abdominal pain and emergency department evaluation. Emerg Med Clin North Am2001;19(1).
6. Kamin RA, Nowicki TA, Courtney DS, Powers RD. Pearls and pitfalls in the emergency department evaluation of abdominal pain. Emerg Med Clin North Am 2003;21(1).
7. King KE, Wightmen JM. Abdominal pain.
In: Marx JA (ed.). Rosen’s Emergency Medicine: Concepts and Clinical Practice, 5th ed., St. Louis: Mosby, 2002.
8. Leung AKC, Sigalet DL. Acute abdominal pain in children. Am Fam Physician 2000;67(11).
9. Marincek B. Nontraumatic abdominal emergencies: acute abdominal pain:
diagnostic strategies. Eur Radiol 2002;12(19):2136–2150.
13. Newton E, Mandavia S. Surgical
complications of selected gastrointestinal emergencies. Emerg Med Clinic North Am 2003;21(4).
10. Nicholson V. Abdominal pain. In: Hamilton GC (ed.). Presenting Signs and Symptoms in the Emergency Department: Evaluation and Treatment. Baltimore: Williams and Wilkins, 1993.
11. Silen W. Cope’s Early Diagnosis of the Acute Abdomen, 20th ed., New York: Oxford University Press, 2000.
12. Thomas SH, Silen W. Effect of diagnostic efficiency of analgesia for undifferentiated abdominal pain. Br J Surg2003;90:5–9.
Abnormal behavior
Scope of the problem
Patients manifesting abnormal behavior are com- mon in emergency departments (EDs). They rep- resent one of the most challenging classes of patients the emergency physician must treat. The causes of abnormal behavior are exceedingly diverse and require physicians to maintain a high level of vigilance to determine whether an under- lying medical disorder exists. In 1998, it was esti- mated that nearly 4% of the approximately 100.4 million ED visits in the US were for behavioral problems. Many of these patients present “for medical clearance” prior to an intended psychi- atric hospitalization. It is important that these patients be treated with the same sensitivity as every patient in the ED. “Medical clearance”
should include a comprehensive medical evalua- tion to identify any potential underlying medical problem that may be responsible for the changes in behavior.
Pathophysiology
The physiology of behavior represents a complex interplay of human physiology and the environ- ment in which it exists. Historically, changes in behavior have been classified as being of func- tional (psychiatric) or organic (medical) etiology.
These classifications are dated, as neuropatho- physiologic mechanisms of psychiatric disease have advanced over the past decades. Examples include aberrations in neurotransmitter trans- duction in depression (serotonin), schizophrenia (dopamine) and Alzheimer’s disease (acetyl- choline). Pharmacologic therapy directed at modulation of these neurotransmitters has greatly advanced the treatment and prognosis of patients suffering with these illnesses.
History
Prior to obtaining the history, the safety of the patient and staff should be ensured. Patients who are altered or violent may be unable or unwilling to give an adequate history. It is important to seek additional sources of information from para- medics, police, family members or witnesses.
Is this an acute or chronic condition?
The temporal nature of these behavioral changes is a good place to start when obtaining the his- tory. Sudden behavioral changes in a previously healthy person are more likely to herald an underlying medical disorder. In contrast, demen- tia is characterized by progressively worsening cognitive function.
If acute, what were the events leading up to the change in behavior?
Is there an antecedent history of trauma, ingestion, medication noncompliance, or new medication(s) that might explain the patient’s symptoms? Has the patient had a recent social stressor such as difficulty with work, family or a relationship that serves as the precipitant.
Does the patient have a history of psychiatric illness?
Patients with a history of psychiatric illness are more likely to have an underlying functional dis- order as the cause of their abnormal behavior.
Ask the patient if he or she has a history of depres- sion, mania, schizophrenia or anxiety. Does the patient have a psychiatrist or psychotherapist? If so, it is important to attempt to contact that indi- vidual for additional history and consultation about disposition once underlying medical ill- nesses have been excluded. Many patients suffer from undiagnosed depression. The mnemonic SIG-E-CAPS is helpful when evaluating patients for possible depression (Table 10.1).