108 PART 2 Cardinal Manifestations and Presentation of Diseases

Echocardiography Echocardiography (nonstress) is not necessarily routine in patients with chest discomfort. However, in patients

with an uncertain diagnosis, particularly those with nondiagnostic

ST elevation, ongoing symptoms, or hemodynamic instability,

detection of abnormal regional wall motion provides evidence of

possible ischemic dysfunction. Echocardiography is diagnostic in

patients with mechanical complications of MI or in patients with

pericardial tamponade. Transthoracic echocardiography is poorly

sensitive for aortic dissection, although an intimal flap may sometimes be detected in the ascending aorta.

MRI (See Chap. 241) Cardiac magnetic resonance (CMR) imaging

is an evolving, versatile technique for structural and functional

evaluation of the heart and the vasculature of the chest. CMR can be

performed as a modality for pharmacologic stress perfusion imaging. Gadolinium-enhanced CMR can provide early detection of MI,

defining areas of myocardial necrosis accurately, and can delineate

patterns of myocardial disease that are often useful in discriminating

ischemic from nonischemic myocardial injury. Although usually

not practical for the urgent evaluation of acute chest discomfort,

CMR can be a useful modality for cardiac structural evaluation of

patients with elevated cardiac troponin levels in the absence of definite coronary artery disease. CMR coronary angiography is in its

early stages. MRI also permits highly accurate assessment for aortic

dissection but is infrequently used as the first test because CT and

transesophageal echocardiography are usually more practical.

■ CRITICAL PATHWAYS FOR ACUTE CHEST

DISCOMFORT

Because of the challenges inherent in reliably identifying the small proportion of patients with serious causes of acute chest discomfort while

not exposing the larger number of low-risk patients to unnecessary

testing and extended ED or hospital evaluations, many medical centers

have adopted critical pathways to expedite the assessment and management of patients with nontraumatic chest pain, often in dedicated chest

pain units. Such pathways are generally aimed at (1) rapid identification, triage, and treatment of high-risk cardiopulmonary conditions

(e.g., STEMI); (2) accurate identification of low-risk patients who can

be safely observed in units with less intensive monitoring, undergo

early noninvasive testing, or be discharged home; and (3) through

more efficient and systematic accelerated diagnostic protocols, safe

reduction in costs associated with overuse of testing and unnecessary

hospitalizations. In some studies, provision of protocol-driven care in

chest pain units has decreased costs and overall duration of hospital

evaluation with no detectable excess of adverse clinical outcomes.

■ OUTPATIENT EVALUATION OF CHEST

DISCOMFORT

Chest pain is common in outpatient practice, with a lifetime prevalence of 20–40% in the general population. More than 25% of patients

with MI have had a related visit with a primary care physician in the

previous month. The diagnostic principles are the same as in the ED.

However, the pretest probability of an acute cardiopulmonary cause is

significantly lower. Therefore, testing paradigms are less intense, with

an emphasis on the history, physical examination, and ECG. Moreover,

decision-aids developed for settings with a high prevalence of significant cardiopulmonary disease have lower positive predictive value

when applied in the practitioner’s office. However, in general, if the

level of clinical suspicion of ACS is sufficiently high to consider troponin testing, the patient should be referred to the ED for evaluation.

■ FURTHER READING

Amsterdam EA et al: Testing of low-risk patients presenting to the

emergency department with chest pain: A scientific statement from

the American Heart Association. Circulation 122:1756, 2010.

Chapman AR et al: Association of high-sensitivity cardiac troponin I

concentration with cardiac outcomes in patients with suspected acute

coronary syndrome. JAMA 318:1913, 2017.

Fanaroff AC et al: Does this patient with chest pain have acute coronary syndrome? JAMA 314:1955, 2015.

Hsia RY et al: A national study of the prevalence of life-threatening

diagnoses in patients with chest pain. JAMA Intern Med 176:1029,

2016.

Mahler SA et al: Safely identifying emergency department patients

with acute chest pain for early discharge: HEART pathway accelerated diagnostic protocol. Circulation 138:2456, 2018.

Correctly diagnosing acute abdominal pain can be quite challenging.

Few clinical situations require greater judgment, because the most

catastrophic of events may be forecast by the subtlest of symptoms and

signs. In every instance, the clinician must distinguish those conditions

that require urgent intervention from those that do not and can best

be managed nonoperatively. A meticulously executed, detailed history

and physical examination are critically important for focusing the differential diagnosis and allowing the diagnostic evaluation to proceed

expeditiously (Table 15-1).

The etiologic classification in Table 15-2, although not complete,

provides a useful framework for evaluating patients with abdominal

pain.

Any patient with abdominal pain of recent onset requires an early

and thorough evaluation. The most common causes of abdominal pain

on admission are nonspecific abdominal pain, acute appendicitis, pain

of urologic origin, and intestinal obstruction. A diagnosis of “acute or

surgical abdomen” is not acceptable because of its often misleading

and erroneous connotations. Most patients who present with acute

abdominal pain will have self-limited disease processes. However,

it is important to remember that pain severity does not necessarily

correlate with the severity of the underlying condition. And, the presence or absence of various degrees of “hunger” is unreliable as a sole

indicator of the severity of intraabdominal disease. The most obvious

of “acute abdomens” may not require operative intervention, and the

mildest of abdominal pains may herald an urgently correctable disease.

■ SOME MECHANISMS OF PAIN ORIGINATING IN

THE ABDOMEN

Inflammation of the Parietal Peritoneum The pain of parietal peritoneal inflammation is steady and aching in character and is

located directly over the inflamed area, its exact reference being possible because it is transmitted by somatic nerves supplying the parietal

peritoneum. The intensity of the pain is dependent on the type and

amount of material to which the peritoneal surfaces are exposed in a

given time period. For example, the sudden release of a small quantity

15 Abdominal Pain

Danny O. Jacobs

TABLE 15-1 Some Key Components of the Patient’s History

Age

Time and mode of onset of the pain

Pain characteristics

Duration of symptoms

Location of pain and sites of radiation

Associated symptoms and their relationship to the pain

Nausea, emesis, and anorexia

Diarrhea, constipation, or other changes in bowel habits

Menstrual history

109Abdominal Pain CHAPTER 15

by palpation or by movement such as with coughing or sneezing. The

patient with peritonitis characteristically lies quietly in bed, preferring

to avoid motion, in contrast to the patient with colic, who may be

thrashing in discomfort.

Another characteristic feature of peritoneal irritation is tonic reflex

spasm of the abdominal musculature, localized to the involved body

segment. Its intensity depends on the integrity of the nervous system,

the location of the inflammatory process, and the rate at which it develops. Spasm over a perforated retrocecal appendix or perforation into

the lesser peritoneal sac may be minimal or absent because of the protective effect of overlying viscera. Catastrophic abdominal emergencies

may be associated with minimal or no detectable pain or muscle spasm

in obtunded, seriously ill, debilitated, immunosuppressed, or psychotic

patients. A slowly developing process also often greatly attenuates the

degree of muscle spasm.

Obstruction of Hollow Viscera Intraluminal obstruction classically elicits intermittent or colicky abdominal pain that is not as well

localized as the pain of parietal peritoneal irritation. However, the

absence of cramping discomfort can be misleading because distention of a hollow viscus may also produce steady pain with only rare

paroxysms.

Small-bowel obstruction often presents as poorly localized, intermittent periumbilical or supraumbilical pain. As the intestine progressively dilates and loses muscular tone, the colicky nature of the pain

may diminish. With superimposed strangulating obstruction, pain

may spread to the lower lumbar region if there is traction on the root

of the mesentery. The colicky pain of colonic obstruction is of lesser

intensity, is commonly located in the infraumbilical area, and may

often radiate to the lumbar region.

Sudden distention of the biliary tree produces a steady rather than

colicky type of pain; hence, the term biliary colic is misleading. Acute

distention of the gallbladder typically causes pain in the right upper

quadrant with radiation to the right posterior region of the thorax or

to the tip of the right scapula, but discomfort is also not uncommonly

found near the midline. Distention of the common bile duct often

causes epigastric pain that may radiate to the upper lumbar region.

Considerable variation is common, however, so that differentiation

between gallbladder or common ductal disease may be impossible.

Gradual dilatation of the biliary tree, as can occur with carcinoma of

the head of the pancreas, may cause no pain or only a mild aching sensation in the epigastrium or right upper quadrant. The pain of distention of the pancreatic ducts is similar to that described for distention of

the common bile duct but, in addition, is very frequently accentuated

by recumbency and relieved by the upright position.

Obstruction of the urinary bladder usually causes dull, low-intensity

pain in the suprapubic region. Restlessness, without specific complaint

of pain, may be the only sign of a distended bladder in an obtunded

patient. In contrast, acute obstruction of the intravesicular portion of the

ureter is characterized by severe suprapubic and flank pain that radiates

to the penis, scrotum, or inner aspect of the upper thigh. Obstruction

of the ureteropelvic junction manifests as pain near the costovertebral

angle, whereas obstruction of the remainder of the ureter is associated

with flank pain that often extends into the same side of the abdomen.

Vascular Disturbances A frequent misconception is that pain due

to intraabdominal vascular disturbances is sudden and catastrophic in

nature. Certain disease processes, such as embolism or thrombosis of

the superior mesenteric artery or impending rupture of an abdominal

aortic aneurysm, can certainly be associated with diffuse, severe pain.

Yet, just as frequently, the patient with occlusion of the superior mesenteric artery only has mild continuous or cramping diffuse pain for 2 or

3 days before vascular collapse or findings of peritoneal inflammation

appear. The early, seemingly insignificant discomfort is caused by

hyperperistalsis rather than peritoneal inflammation. Indeed, absence

of tenderness and rigidity in the presence of continuous, diffuse pain

(e.g., “pain out of proportion to physical findings”) in a patient likely to

have vascular disease is quite characteristic of occlusion of the superior

mesenteric artery. Abdominal pain with radiation to the sacral region,

TABLE 15-2 Some Important Causes of Abdominal Pain

Pain Originating in the Abdomen

Parietal peritoneal inflammation

Bacterial contamination

 Perforated appendix or other

perforated viscus

 Pelvic inflammatory disease

Chemical irritation

 Perforated ulcer

 Pancreatitis

 Mittelschmerz

Mechanical obstruction of hollow

viscera

 Obstruction of the small or large

intestine

Obstruction of the biliary tree

Obstruction of the ureter

Vascular disturbances

Embolism or thrombosis

Vascular rupture

Pressure or torsional occlusion

Sickle cell anemia

Abdominal wall

Distortion or traction of mesentery

Trauma or infection of muscles

Distension of visceral surfaces, e.g., by

hemorrhage

Hepatic or renal capsules

Inflammation

Appendicitis

Typhoid fever

 Neutropenic enterocolitis or

“typhlitis”

Pain Referred from Extraabdominal Source

Cardiothoracic

Acute myocardial infarction

 Myocarditis, endocarditis,

pericarditis

Congestive heart failure

Pneumonia (especially lower lobes)

Pulmonary embolus

Pleurodynia

Pneumothorax

Empyema

 Esophageal disease, including

spasm, rupture, or inflammation

Genitalia

Torsion of the testis

Metabolic Causes

Diabetes

Uremia

Hyperlipidemia

Hyperparathyroidism

Acute adrenal insufficiency

Familial Mediterranean fever

Porphyria

C1 esterase inhibitor deficiency

(angioneurotic edema)

Neurologic/Psychiatric Causes

Herpes zoster

Tabes dorsalis

Causalgia

Radiculitis from infection or arthritis

Spinal cord or nerve root compression

Functional disorders

Psychiatric disorders

Toxic Causes

Lead poisoning

Insect or animal envenomation

Black widow spider bites

Snake bites

Uncertain Mechanisms

Narcotic withdrawal

Heat stroke

of sterile acidic gastric juice into the peritoneal cavity causes much

more pain than the same amount of grossly contaminated neutral feces.

Enzymatically active pancreatic juice incites more pain and inflammation than does the same amount of sterile bile containing no potent

enzymes. Blood is normally only a mild irritant, and the response to

urine is also typically bland, so exposure of blood and urine to the

peritoneal cavity may go unnoticed unless it is sudden and massive.

Bacterial contamination, such as may occur with pelvic inflammatory

disease or perforated distal intestine, causes low-intensity pain until

multiplication causes significant amounts of inflammatory mediators

to be released. Patients with perforated upper gastrointestinal ulcers

may present entirely differently depending on how quickly gastric

juices enter the peritoneal cavity and their pH. Thus, the rate at which

any inflammatory material irritates the peritoneum is important.

The pain of peritoneal inflammation is invariably accentuated by

pressure or changes in tension of the peritoneum, whether produced

110 PART 2 Cardinal Manifestations and Presentation of Diseases

flank, or genitalia should always signal the possible presence of a rupturing abdominal aortic aneurysm. This pain may persist over a period

of several days before rupture and collapse occur.

Abdominal Wall Pain arising from the abdominal wall is usually

constant and aching. Movement, prolonged standing, and pressure

accentuate the discomfort and associated muscle spasm. In the relatively rare case of hematoma of the rectus sheath, now most frequently

encountered in association with anticoagulant therapy, a mass may be

present in the lower quadrants of the abdomen. Simultaneous involvement of muscles in other parts of the body usually serves to differentiate myositis of the abdominal wall from other processes that might

cause pain in the same region.

■ REFERRED PAIN IN ABDOMINAL DISEASE

Pain referred to the abdomen from the thorax, spine, or genitalia may

present a diagnostic challenge because diseases of the upper part of the

abdominal cavity such as acute cholecystitis or perforated ulcer may

be associated with intrathoracic complications. A most important, yet

often forgotten, dictum is that the possibility of intrathoracic disease

must be considered in every patient with abdominal pain, especially if

the pain is in the upper abdomen.

Systematic questioning and examination directed toward detecting myocardial or pulmonary infarction, pneumonia, pericarditis, or

esophageal disease (the intrathoracic diseases that most often masquerade as abdominal emergencies) will often provide sufficient clues

to establish the proper diagnosis. Diaphragmatic pleuritis resulting

from pneumonia or pulmonary infarction may cause pain in the right

upper quadrant and pain in the supraclavicular area, the latter radiation to be distinguished from the referred subscapular pain caused by

acute distention of the extrahepatic biliary tree. The ultimate decision

as to the origin of abdominal pain may require deliberate and planned

observation over a period of several hours, during which repeated

questioning and examination will provide the diagnosis or suggest the

appropriate studies.

Referred pain of thoracic origin is often accompanied by splinting

of the involved hemithorax with respiratory lag and a decrease in

excursion more marked than that seen in the presence of intraabdominal disease. In addition, apparent abdominal muscle spasm caused by

referred pain will diminish during the inspiratory phase of respiration,

whereas it persists throughout both respiratory phases if it is of abdominal origin. Palpation over the area of referred pain in the abdomen also

does not usually accentuate the pain and, in many instances, actually

seems to relieve it.

Thoracic disease and abdominal disease frequently coexist and may

be difficult or impossible to differentiate. For example, the patient with

known biliary tract disease often has epigastric pain during myocardial

infarction, or biliary colic may be referred to the precordium or left

shoulder in a patient who has suffered previously from angina pectoris.

For an explanation of the radiation of pain to a previously diseased

area, see Chap. 13.

Referred pain from the spine, which usually involves compression

or irritation of nerve roots, is characteristically intensified by certain motions such as cough, sneeze, or strain and is associated with

hyperesthesia over the involved dermatomes. Pain referred to the abdomen from the testes or seminal vesicles is generally accentuated by the

slightest pressure on either of these organs. The abdominal discomfort

experienced is of dull, aching character and is poorly localized.

■ METABOLIC ABDOMINAL CRISES

Pain of metabolic origin may simulate almost any other type of

intraabdominal disease. Several mechanisms may be at work. In certain instances, such as hyperlipidemia, the metabolic disease itself may

be accompanied by an intraabdominal process such as pancreatitis,

which can lead to unnecessary laparotomy unless recognized. C1

esterase deficiency associated with angioneurotic edema is often associated with episodes of severe abdominal pain. Whenever the cause of

abdominal pain is obscure, a metabolic origin always must be considered. Abdominal pain is also the hallmark of familial Mediterranean

fever (Chap. 369).

The pain of porphyria and of lead colic is usually difficult to distinguish from that of intestinal obstruction, because severe hyperperistalsis is a prominent feature of both. The pain of uremia or diabetes

is nonspecific, and the pain and tenderness frequently shift in location

and intensity. Diabetic acidosis may be precipitated by acute appendicitis or intestinal obstruction, so if prompt resolution of the abdominal

pain does not result from correction of the metabolic abnormalities, an

underlying organic problem should be suspected. Black widow spider

bites produce intense pain and rigidity of the abdominal muscles and

back, an area infrequently involved in intraabdominal disease.

■ IMMUNOCOMPROMISE

Evaluating and diagnosing causes of abdominal pain in immunosuppressed or otherwise immunocompromised patients is very difficult.

This includes those who have undergone organ transplantation; who

are receiving immunosuppressive treatments for autoimmune diseases, chemotherapy, or glucocorticoids; who have AIDS; and who

are very old. In these circumstances, normal physiologic responses

may be absent or masked. In addition, unusual infections may cause

abdominal pain where the etiologic agents include cytomegalovirus,

mycobacteria, protozoa, and fungi. These pathogens may affect all

gastrointestinal organs, including the gallbladder, liver, and pancreas,

as well as the gastrointestinal tract, causing occult or overtly symptomatic perforations of the latter. Splenic abscesses due to Candida or

Salmonella infection should also be considered, especially when evaluating patients with left upper quadrant or left flank pain. Acalculous

cholecystitis may be observed in immunocompromised patients or

those with AIDS, where it is often associated with cryptosporidiosis or

cytomegalovirus infection.

Neutropenic enterocolitis (typhlitis) is often identified as a cause

of abdominal pain and fever in some patients with bone marrow suppression due to chemotherapy. Acute graft-versus-host disease should

be considered in this circumstance. Optimal management of these

patients requires meticulous follow-up including serial examinations

to assess the need for more surgical intervention, for example, to

address perforation.

■ NEUROGENIC CAUSES

Diseases that injure sensory nerves may cause causalgic pain. This

pain has a burning character and is usually limited to the distribution

of a given peripheral nerve. Stimuli that are normally not painful such

as touch or a change in temperature may be causalgic and are often

present even at rest. The demonstration of irregularly spaced cutaneous

“pain spots” may be the only indication that an old nerve injury exists.

Even though the pain may be precipitated by gentle palpation, rigidity

of the abdominal muscles is absent, and the respirations are not usually

disturbed. Distention of the abdomen is uncommon, and the pain has

no relationship to food intake.

Pain arising from spinal nerves or roots comes and goes suddenly

and is of a lancinating type (Chap. 17). It may be caused by herpes

zoster, impingement by arthritis, tumors, a herniated nucleus pulposus,

diabetes, or syphilis. It is not associated with food intake, abdominal

distention, or changes in respiration. Severe muscle spasms, when present, may be relieved by, but are certainly not accentuated by, abdominal

palpation. The pain is made worse by movement of the spine and is

usually confined to a few dermatomes. Hyperesthesia is very common.

Pain due to functional causes conforms to none of the aforementioned patterns. Mechanisms of disease are not clearly established.

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder

characterized by abdominal pain and altered bowel habits. The diagnosis is made on the basis of clinical criteria (Chap. 327) and after

exclusion of demonstrable structural abnormalities. The episodes of

abdominal pain may be brought on by stress, and the pain varies considerably in type and location. Nausea and vomiting are rare. Localized

111Abdominal Pain CHAPTER 15

TABLE 15-3 Differential Diagnoses of Abdominal Pain by Location

Right Upper Quadrant Epigastric Left Upper Quadrant

Cholecystitis

Cholangitis

Pancreatitis

Pneumonia/empyema

Pleurisy/pleurodynia

Subdiaphragmatic

abscess

Hepatitis

Budd-Chiari syndrome

Peptic ulcer disease

Gastritis

GERD

Pancreatitis

Myocardial infarction

Pericarditis

Ruptured aortic

aneurysm

Esophagitis

Splenic infarct

Splenic rupture

Splenic abscess

Gastritis

Gastric ulcer

Pancreatitis

Subdiaphragmatic

abscess

Right Lower Quadrant Periumbilical Left Lower Quadrant

Appendicitis

Salpingitis

Inguinal hernia

Ectopic pregnancy

Nephrolithiasis

Inflammatory bowel

disease

Mesenteric

lymphadenitis

Typhlitis

Early appendicitis

Gastroenteritis

Bowel obstruction

Ruptured aortic

aneurysm

Diverticulitis

Salpingitis

Inguinal hernia

Ectopic pregnancy

Nephrolithiasis

Irritable bowel syndrome

Inflammatory bowel

disease

Diffuse Nonlocalized Pain

Gastroenteritis

Mesenteric ischemia

Bowel obstruction

Irritable bowel syndrome

Peritonitis

Diabetes

Malaria

Familial Mediterranean

fever

Metabolic diseases

Psychiatric disease

Abbreviation: GERD, gastroesophageal reflux disease.

tenderness and muscle spasm are inconsistent or absent. The causes of

IBS or related functional disorders are not yet fully understood.

APPROACH TO THE PATIENT

Abdominal Pain

Few abdominal conditions require such urgent operative intervention that an orderly approach needs to be abandoned, no matter

how ill the patient is. Only patients with exsanguinating intraabdominal hemorrhage (e.g., ruptured aneurysm) must be rushed

to the operating room immediately, but in such instances, only a

few minutes are required to assess the critical nature of the problem. Under these circumstances, all obstacles must be swept aside,

adequate venous access for fluid replacement obtained, and the

operation begun. Unfortunately, many of these patients may die in

the radiology department or the emergency room while awaiting

unnecessary examinations. There are no absolute contraindications

to operation when massive intraabdominal hemorrhage is present.

Fortunately, this situation is relatively rare. This statement does

not necessarily apply to patients with intraluminal gastrointestinal

hemorrhage, who can often be managed by other means (Chap.

48). In these patients, obtaining a detailed history when possible

can be extremely helpful even though it can be laborious and timeconsuming. Decision-making regarding next steps is facilitated and

a reasonably accurate diagnosis can be made before any further

diagnostic testing is undertaken.

In cases of acute abdominal pain, a diagnosis can be readily

established in most instances, whereas success is not so frequent in

patients with chronic pain. IBS is one of the most common causes of

abdominal pain and must always be kept in mind (Chap. 327). The

location of the pain can assist in narrowing the differential diagnosis (Table 15-3); however, the chronological sequence of events in the

patient’s history is often more important than the pain’s location.

Careful attention should be paid to the extraabdominal regions.

Narcotics or analgesics should not be withheld until a definitive

diagnosis or a definitive plan has been formulated; obfuscation of

the diagnosis by adequate analgesia is unlikely.

An accurate menstrual history in a female patient is essential. It

is important to remember that normal anatomic relationships can

be significantly altered by the gravid uterus. Abdominal and pelvic

pain may occur during pregnancy due to conditions that do not

require operation. Lastly, some otherwise noteworthy laboratory

values (e.g., leukocytosis) may represent the normal physiologic

changes of pregnancy.

In the examination, simple critical inspection of the patient,

for example, of facies, position in bed, and respiratory activity,

provides valuable clues. The amount of information to be gleaned

is directly proportional to the gentleness and thoroughness of the

examiner. Once a patient with peritoneal inflammation has been

examined brusquely, accurate assessment by the next examiner

becomes almost impossible. Eliciting rebound tenderness by sudden release of a deeply palpating hand in a patient with suspected

peritonitis is cruel and unnecessary. The same information can

be obtained by gentle percussion of the abdomen (rebound tenderness on a miniature scale), a maneuver that can be far more

precise and localizing. Asking the patient to cough will elicit true

rebound tenderness without the need for placing a hand on the

abdomen. Furthermore, the forceful demonstration of rebound

tenderness will startle and induce protective spasm in a nervous or

worried patient in whom true rebound tenderness is not present. A

palpable gallbladder will be missed if palpation is so aggressive that

voluntary muscle spasm becomes superimposed on involuntary

muscular rigidity.

As with history taking, sufficient time should be spent in the

examination. Abdominal signs may be minimal but, nevertheless,

if accompanied by consistent symptoms, may be exceptionally

meaningful. Abdominal signs may be virtually or totally absent in

cases of pelvic peritonitis, so careful pelvic and rectal examinations

are mandatory in every patient with abdominal pain. Tenderness

on pelvic or rectal examination in the absence of other abdominal

signs can be caused by operative indications such as perforated

appendicitis, diverticulitis, twisted ovarian cyst, and many others.

Much attention has been paid to the presence or absence of peristaltic sounds, their quality, and their frequency. Auscultation of

the abdomen is one of the least revealing aspects of the physical

examination of a patient with abdominal pain. Catastrophes such

as a strangulating small-intestinal obstruction or perforated appendicitis may occur in the presence of normal peristaltic sounds. Conversely, when the proximal part of the intestine above obstruction

becomes markedly distended and edematous, peristaltic sounds

may lose the characteristics of borborygmi and become weak or

absent, even when peritonitis is not present. It is usually the severe

chemical peritonitis of sudden onset that is associated with the truly

silent abdomen.

Laboratory examinations may be valuable in assessing the patient

with abdominal pain, yet, with few exceptions, they rarely establish

a diagnosis. Leukocytosis should never be the single deciding factor as to whether or not operation is indicated. A white blood cell

count >20,000/μL may be observed with perforation of a viscus, but

pancreatitis, acute cholecystitis, pelvic inflammatory disease, and

intestinal infarction may also be associated with marked leukocytosis. A normal white blood cell count is not rare in cases of perforation of abdominal viscera. A diagnosis of anemia may be more

helpful than the white blood cell count, especially when combined

with the history.

The urinalysis may reveal the state of hydration or rule out severe

renal disease, diabetes, or urinary infection. Blood urea nitrogen,

glucose, and serum bilirubin levels and liver function tests may be

112 PART 2 Cardinal Manifestations and Presentation of Diseases

helpful. Serum amylase levels may be increased by many diseases

other than pancreatitis, for example, perforated ulcer, strangulating

intestinal obstruction, and acute cholecystitis; thus, elevations of

serum amylase do not rule in or rule out the need for an operation.

Plain and upright or lateral decubitus radiographs of the abdomen have limited utility and may be unnecessary in some patients

who have substantial evidence of some diseases such as acute

appendicitis or strangulated external hernia. Where the indications

for surgical or medical intervention are not clear, low-dose computed tomography is preferred to abdominal radiography when

evaluating nontraumatic acute abdominal pain.

Very rarely, barium or water-soluble contrast study of the upper

part of the gastrointestinal tract is an appropriate radiographic

investigation and may demonstrate partial intestinal obstruction

that may elude diagnosis by other means. If there is any question

of obstruction of the colon, oral administration of barium sulfate should be avoided. On the other hand, in cases of suspected

colonic obstruction (without perforation), a contrast enema may

be diagnostic.

In the absence of trauma, peritoneal lavage has been replaced as

a diagnostic tool by CT scanning and laparoscopy. Ultrasonography has proved to be useful in detecting an enlarged gallbladder or

pancreas, the presence of gallstones, an enlarged ovary, or a tubal

pregnancy. Laparoscopy is especially helpful in diagnosing pelvic

conditions, such as ovarian cysts, tubal pregnancies, salpingitis,

acute appendicitis, and other disease processes. Laparoscopy has a

particular advantage over imaging in that the underlying etiologic

condition can often be definitively addressed.

Radioisotopic hepatobiliary iminodiacetic acid scans (HIDAs)

may help differentiate acute cholecystitis or biliary colic from

acute pancreatitis. A CT scan may demonstrate an enlarged pancreas, ruptured spleen, or thickened colonic or appendiceal wall

and streaking of the mesocolon or mesoappendix characteristic of

diverticulitis or appendicitis.

Sometimes, even under the best circumstances with all available

aids and with the greatest of clinical skill, a definitive diagnosis

cannot be established at the time of the initial examination. And, in

some cases, operation may be indicated based on clinical grounds

alone. Should that decision be questionable, watchful waiting with

repeated questioning and examination will often elucidate the true

nature of the illness and indicate the proper course of action.

Acknowledgment

The author gratefully acknowledges the enormous contribution to this

chapter and the approach it espouses of William Silen, who wrote this

chapter for many editions.

■ FURTHER READING

Bhangu A et al: Acute appendicitis: Modern understanding of pathogenesis, diagnosis and management. Lancet 386:1278, 2015.

Cartwright SL, Knudson MP: Diagnostic imaging of acute abdominal pain in adults. Am Fam Phys 91:452, 2015.

Huckins DS et al: Diagnostic performance of a biomarker panel as a

negative predictor for acute appendicitis in acute emergency department patients with abdominal pain. Am J Emerg Med 35:418, 2017.

Nayor J et al: Tracing the cause of abdominal pain. N Engl J Med

375:e8, 2016.

Phillips MT: Clinical yield of computed tomography scans in the

emergency department for abdominal pain. J Invest Med 64:542,

2016.

Silen W, Cope Z: Cope’s Early Diagnosis of the Acute Abdomen, 22nd ed.

New York, Oxford University Press, 2010.

Headache is among the most common reasons patients seek medical

attention and is responsible, on a global basis, for more disability than

any other neurologic problem. Diagnosis and management are based

on a careful clinical approach augmented by an understanding of the

anatomy, physiology, and pharmacology of the nervous system pathways mediating the various headache syndromes. This chapter will

focus on the general approach to a patient with headache; migraine and

other primary headache disorders are discussed in Chap. 430.

■ GENERAL PRINCIPLES

A classification system developed by the International Headache

Society (www.ihs-headache.org/en/resources/guidelines/) characterizes

headache as primary or secondary (Table 16-1). Primary headaches

are those in which headache and its associated features are the disorder

itself, whereas secondary headaches are those caused by exogenous disorders (Headache Classification Committee of the International Headache Society, 2018). Primary headache often results in considerable

disability and a decrease in the patient’s quality of life. Mild secondary

headache, such as that seen in association with upper respiratory tract

infections, is common but rarely worrisome. Life-threatening headache

is relatively uncommon, but vigilance is required in order to recognize

and appropriately treat such patients.

■ ANATOMY AND PHYSIOLOGY OF HEADACHE

Pain usually occurs when peripheral nociceptors are stimulated in

response to tissue injury, visceral distension, or other factors (Chap. 13).

In such situations, pain perception is a normal physiologic response

mediated by a healthy nervous system. Pain can also result when

pain-producing pathways of the peripheral or central nervous system

(CNS) are damaged or activated inappropriately. Headache may originate from either or both mechanisms. Relatively few cranial structures

are pain producing; these include the scalp, meningeal arteries, dural

sinuses, falx cerebri, and proximal segments of the large pial arteries.

The ventricular ependyma, choroid plexus, pial veins, and much of the

brain parenchyma are not pain producing.

The key structures involved in primary headache are the following:

• The large intracranial vessels and dura mater, and the peripheral

terminals of the trigeminal nerve that innervate these structures

• The caudal portion of the trigeminal nucleus, which extends into

the dorsal horns of the upper cervical spinal cord and receives input

from the first and second cervical nerve roots (the trigeminocervical

complex)

• Rostral pain-processing regions, such as the ventroposteromedial

thalamus and the cortex

• The pain-modulatory systems in the brain that modulate input from

the trigeminal nociceptors at all levels of the pain-processing pathways and influence vegetative functions, such as the hypothalamus

and brainstem

16 Headache

Peter J. Goadsby

TABLE 16-1 Common Causes of Headache

PRIMARY HEADACHE SECONDARY HEADACHE

TYPE % TYPE %

Tension-type 69 Systemic infection 63

Migraine 16 Head injury 4

Idiopathic stabbing 2 Vascular disorders 1

Exertional 1 Subarachnoid hemorrhage <1

Cluster 0.1 Brain tumor 0.1

Source: After J Olesen et al: The Headaches. Philadelphia, Lippincott Williams &

Wilkins, 2005.

113Headache CHAPTER 16

The trigeminovascular system innervates the large intracranial

vessels and dura mater via the trigeminal nerve. Cranial autonomic

symptoms, such as lacrimation, conjunctival injection, nasal congestion, rhinorrhea, periorbital swelling, aural fullness, and ptosis,

are prominent in the trigeminal autonomic cephalalgias (TACs),

including cluster headache and paroxysmal hemicrania, and may also

be seen in migraine, even in children. These autonomic symptoms

reflect activation of cranial parasympathetic pathways, and functional

imaging studies indicate that vascular changes in migraine and cluster

headache, when present, are similarly driven by these cranial autonomic systems. Thus, they are secondary, and not causative, events

in the headache cascade. Moreover, they can often be mistaken for

symptoms or signs of cranial sinus inflammation, which is then overdiagnosed and inappropriately managed. Migraine and other primary

headache types are not “vascular headaches”; these disorders do not

reliably manifest vascular changes, and treatment outcomes cannot be

predicted by vascular effects. Migraine is a brain disorder and is best

understood and managed as such.

■ CLINICAL EVALUATION OF ACUTE,

NEW-ONSET HEADACHE

The patient who presents with a new, severe headache has a differential diagnosis that is quite different from the patient with recurrent

headaches over many years. In new-onset and severe headache, the

probability of finding a potentially serious cause is considerably greater

than in recurrent headache. Patients with recent onset of pain require

prompt evaluation and appropriate treatment. Serious causes to be

considered include meningitis, subarachnoid hemorrhage, epidural or

subdural hematoma, glaucoma, tumor, and purulent sinusitis. When

worrisome symptoms and signs are present (Table 16-2), rapid diagnosis and management are critical.

A careful neurologic examination is an essential first step in the

evaluation. In most cases, patients with an abnormal examination or

a history of recent-onset headache should be evaluated by a computed

tomography (CT) or magnetic resonance imaging (MRI) study of the

brain. As an initial screening procedure for intracranial pathology in

this setting, CT and MRI methods appear to be equally sensitive. In

some circumstances, a lumbar puncture (LP) is also required, unless

a benign etiology can be otherwise established. A general evaluation

of acute headache might include cranial arteries by palpation; cervical

spine by the effect of passive movement of the head and by imaging;

the investigation of cardiovascular and renal status by blood pressure

monitoring and urine examination; and eyes by funduscopy, intraocular pressure measurement, and refraction.

The patient’s psychological state should also be evaluated because a

relationship exists between head pain, depression, and anxiety. This is

intended to identify comorbidity rather than provide an explanation

for the headache, because troublesome headache is seldom simply

caused by mood change. Although it is notable that medicines with

antidepressant actions are also effective in the preventive treatment

TABLE 16-2 Headache Symptoms That Suggest a Serious Underlying

Disorder

Sudden-onset headache

First severe headache

“Worst” headache ever

Vomiting that precedes headache

Subacute worsening over days or weeks

Pain induced by bending, lifting, coughing

Pain that disturbs sleep or presents immediately upon awakening

Known systemic illness

Onset after age 55

Fever or unexplained systemic signs

Abnormal neurologic examination

Pain associated with local tenderness, e.g., region of temporal artery

of both tension-type headache and migraine, each symptom must be

treated optimally.

Underlying recurrent headache disorders may be activated by pain

that follows otologic or endodontic surgical procedures. Thus, pain

about the head as the result of diseased tissue or trauma may reawaken

an otherwise quiescent migraine syndrome. Treatment of the headache is largely ineffective until the cause of the primary problem is

addressed.

Serious underlying conditions that are associated with headache are

described below. Brain tumor is a rare cause of headache and even less

commonly a cause of severe pain. The vast majority of patients presenting with severe headache have a benign cause.

SECONDARY HEADACHE

The management of secondary headache focuses on diagnosis and

treatment of the underlying condition.

■ MENINGITIS

Acute, severe headache with stiff neck and fever suggests meningitis.

LP is mandatory. Often there is striking accentuation of pain with eye

movement. Meningitis can be easily mistaken for migraine in that the

cardinal symptoms of pounding headache, photophobia, nausea, and

vomiting are frequently present, perhaps reflecting the underlying

biology of some of the patients.

Meningitis is discussed in Chaps. 138 and 139.

■ INTRACRANIAL HEMORRHAGE

Acute, maximal in <5 min, severe headache lasting >5 min with stiff

neck but without fever suggests subarachnoid hemorrhage. A ruptured

aneurysm, arteriovenous malformation, or intraparenchymal hemorrhage may also present with headache alone. Rarely, if the hemorrhage

is small or below the foramen magnum, the head CT scan can be

normal. Therefore, LP may be required to diagnose definitively subarachnoid hemorrhage.

Subarachnoid hemorrhage is discussed in Chap. 429, and intracranial hemorrhage in Chap. 428.

■ BRAIN TUMOR

Approximately 30% of patients with brain tumors consider headache

to be their chief complaint. The head pain is usually nondescript—an

intermittent deep, dull aching of moderate intensity, which may worsen

with exertion or change in position and may be associated with nausea

and vomiting. This pattern of symptoms results from migraine far more

often than from brain tumor. The headache of brain tumor disturbs

sleep in about 10% of patients. Vomiting that precedes the appearance

of headache by weeks is highly characteristic of posterior fossa brain

tumors. A history of amenorrhea or galactorrhea should lead one to

question whether a prolactin-secreting pituitary adenoma (or polycystic

ovary syndrome) is the source of headache. Headache arising de novo in

a patient with known malignancy suggests either cerebral metastases or

carcinomatous meningitis. Head pain appearing abruptly after bending,

lifting, or coughing can be due to a posterior fossa mass, a Chiari malformation, or low cerebrospinal fluid (CSF) volume.

Brain tumors are discussed in Chap. 90.

■ TEMPORAL ARTERITIS (SEE ALSO CHAPS. 32 AND 363)

Temporal (giant cell) arteritis is an inflammatory disorder of arteries

that frequently involves the extracranial carotid circulation. It is a

common disorder of the elderly; its annual incidence is 77 per 100,000

individuals aged ≥50. The average age of onset is 70 years, and women

account for 65% of cases. About half of patients with untreated temporal arteritis develop blindness due to involvement of the ophthalmic

artery and its branches; indeed, the ischemic optic neuropathy induced

by giant cell arteritis is the major cause of rapidly developing bilateral

blindness in patients >60 years. Because treatment with glucocorticoids

is effective in preventing this complication, prompt recognition of the

disorder is important.

Typical presenting symptoms include headache, polymyalgia rheumatica (Chap. 363), jaw claudication, fever, and weight loss. Headache