Markovchick Vincent J., Pons Peter T., Bakes Katherine M.(ed.) Emergency medicine secrets. 5th ed

Подождите немного. Документ загружается.

248

LIVER AND BILIARY TRACT DISEASE

CHAPTER 35

Elan S. Levy, MD, and Kaushal H. Shah, MD

1. What are the common manifestations of biliary disease?

Cholelithiasis is the presence of gallstones in the gallbladder without evidence of

infection. Among adults, 8% of men and 17% of women have gallstones, and the

incidence increases with age with an incidence as high as 27% in the elderly.

Biliary colic is right upper quadrant or epigastric pain sometimes radiating to the

right shoulder or scapula. It usually lasts less than 6 hours, is persistent, not colicky,

occurs after a fatty meal, and is thought to be due to transient obstruction of the

cystic duct by a gallstone.

Of patients with colic, 30% progress to cholecystitis, a bacterial overgrowth and

inﬂammation of the gallbladder caused by obstruction of the cystic duct by a stone.

The pain with cholecystitis is similar to biliary colic but persists beyond 6 hours, is

accompanied by a Murphy’s sign, and can be present with or without fever and chills

Choledocholithiasis occurs when a gallstone lodges in the common bile duct (CBD)

and can cause cholecystitis or pancreatitis (if the ampulla of Vater is obstructed)

or both.

Ascending cholangitis is a severe infection of the biliary tract from complete biliary

obstruction (most commonly the CBD) in the presence of a bacterial infection. It

presents as right upper quadrant pain, fever and chills, and jaundice (Charcot’s triad),

although only 25% of patients have all three. It may include shock and mental status

changes (Reynold’s pentad), more commonly seen with gangrenous or

emphysematous cholecystitis

Emphysematous cholecystitis is caused by complete cystic duct obstruction with

subsequent abscess formation in the gallbladder wall by gas-forming bacteria. It is

seen with vascular insufﬁciency, severe burns, and trauma. It is more frequent in men

and diabetic patients and often is accompanied by sepsis.

2. Do all gallstones produce pain? Does a lack of stones preclude

cholecystitis?

Of patients with gallstones, 80% are asymptomatic. Of asymptomatic patients, 15% to

30% develop symptoms within 15 years. Although 90% to 95% of cholecystitis cases

are in the setting of gallstones, 5% to 10% are not secondary to cholelithiasis and

are termed acalculous cholecystitis. It is a difﬁcult diagnosis because it is often a

complication of another process such as diabetes, burns, multisystem trauma, AIDS,

or sepsis.

3. What is Murphy’s sign?

The sign is named after a prominent Chicago surgeon, John B. Murphy (1857–1916).

The patient is asked to take a deep breath while the examiner applies pressure over the

area of the gallbladder. If the gallbladder is inﬂamed, the descending diaphragm forces it

against the examiner’s ﬁngertips, causing pain and often a sudden halt to the inspiration.

A sonographic Murphy’s sign uses the ultrasound probe instead of the examiner’s

ﬁngers and is positive when the site of maximal tenderness localizes to the gallbladder.

The ﬁnding is 97% sensitive for acute cholecystitis.

Chapter 35 LIVER AND BILIARY TRACT DISEASE 249

4. Can a plain radiograph of the abdomen aid diagnosis?

Maybe. However, ultrasound is the preferred ﬁrst-line diagnostic test. Only 10% to 20% of

gallstones contain sufﬁcient calcium to be radiopaque. Air can be seen in the biliary tree or the

gallbladder wall when infection is due to gas-forming bacteria or there is a biliary-intestinal

ﬁstula.

5. What is the gold standard for diagnosing cholecystitis?

Although ultrasound is the test of choice in the ED, a hepatobiliary iminodiacetic acid (HIDA)

scan is the gold standard with 95% accuracy if the gallbladder does not ﬁll with radioisotope

within 4 hours after injection.

6. Is an elevated temperature or white blood cell count necessary for diagnosis?

No, they are not helpful for diagnosis, as is seen in one study in which 71% of patients with

acute nongangrenous cholecystitis were afebrile, and 32% had normal white blood cell count.

Past the age of 60, the typical signs and symptoms may not be present. The sensitivity of the

Murphy’s sign decreases to 48% with age older than 60.

7. Describe the ultrasound ﬁndings in cholecystitis.

Gallstones as small as 2 mm can be detected directly, or sometimes their presence can be

inferred by interference with transmission of ultrasound waves (acoustic shadowing)

(Fig. 35-1). Other helpful ﬁndings include a thickened gallbladder wall (.3 mm), ﬂuid

collections around the gallbladder (pericholecystic ﬂuid), and common ductal dilation

(.6 mm). The ultrasound is 94% sensitive and 78% speciﬁc for identifying cholecystitis

KEY POINTS: ULTRASOUND FINDINGS OF CHOLECYSTITIS

1. Presence of gallstones

2. Gallbladder wall thickening .3 mm

3. Pericholecystic ﬂuid

4. CBD dilatation .6 mm

8. When should elective surgery be considered in patients with asymptomatic

cholelithiasis?

Cholecystectomy should be considered in diabetics, patients with a porcelain gallbladder, and

patients with a history of biliary pancreatitis.

Diabetics have increased morbidity and mortality when urgent cholecystectomy is done in

the setting of cholecystitis.

Calciﬁed or porcelain gallbladders have a 22% association with carcinoma.

The risks of pancreatitis may outweigh the risks of elective cholecystectomy.

9. What are Courvoisier’s law, Klatskin’s tumor, and Fitz-Hugh-Curtis syndrome?

Courvoisier’s law states that a palpable gallbladder in the setting of painless jaundice is

likely to represent obstruction of the CBD by a malignancy, usually carcinoma of the

pancreatic head.

Klatskin’s tumor is a malignant tumor located where the hepatic ducts form the common

duct.

Fitz-Hugh-Curtis syndrome is caused by pelvic inﬂammatory disease extending up the right

paracolic gutter, causing inﬂammation of the capsule of the liver (perihepatitis), and can

lead to adhesions between the liver and abdominal wall.

Chapter 35 LIVER AND BILIARY TRACT DISEASE250

10. What is a porcelain gallbladder?

A gallbladder with calciﬁed walls. This is an important ﬁnding because 22% are associated

with carcinoma, and it is an indication for cholecystectomy in asymptomatic patients. There is

a higher incidence in women and American Indians, especially members of the Pima tribe.

11. Are all gallstones created equal?

No. The most common are cholesterol stones and usually are found in the stereotypical,

female, fat, forty, fertile patient. Patients of Asian descent, those with parasitic infections

(Ascaris lumbricoides), chronic liver/biliary disease, or chronic hemolysis states (i.e., sickle

cell, spherocytosis) are more likely to have pigment stones.

12. What is endoscopic retrograde cholangiopancreatography (ERCP)? What is

the most common complication that presents to the ED after an ERCP

procedure?

ERCP is a procedure that examines the pancreatic and bile ducts for disease or irregularities

with the ability of removing lodged stones and opening narrowed ducts with stents. The most

common serious complication is pancreatitis, which occurs in approximately 1% of cases.

13. What are liver function tests?

Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are markers of acute

liver injury and have no correlation with liver function. Liver function is analyzed best by

measuring factors affected by hepatic protein synthesis. Acute liver failure results in a

decrease in vitamin K-dependent coagulation factors (except factor VIII), leading to a

prolonged prothrombin time. The liver also synthesizes albumin, although its longer half-life

makes it a better marker of subacute or chronic liver disease.

14. What is the difference between conjugated and unconjugated bilirubinemia?

Bilirubin is a breakdown product of hemoglobin and heme-related proteins. In its unconjugated,

hydrophobic form, it is unable to be excreted into bile, although it can traverse the blood-brain

barrier and placenta. Bilirubin is conjugated in the liver with glucuronic acid, making it more

water soluble for excretion into the bile. A predominance of unconjugated bilirubin occurs when

Figure 35-1. Ultrasound image reveals an anechoic gallbladder containing two echogenic

stones, which are creating acoustic shadowing inferiorly. The short arrow is pointed to the gall-

stones within the gallbladder, and the long arrow points to the shadowing effect of the stones.

Chapter 35 LIVER AND BILIARY TRACT DISEASE 251

KEY POINTS: CRITERIA FOR ADMISSION IN PATIENT

WITH HEPATITIS

1. Coagulopathy, international normalized ratio (INR) .3

2. Active bleeding

3. Encephalopathy

4. Unable to tolerate intake by mouth

5. Social issues that make follow up care and compliance problematic

there is overproduction (hemolysis) or decreased conjugation (decreased intrinsic metabolic

activity of the liver by acute or chronic injury). A primarily conjugated bilirubinemia results from

reﬂux into the plasma from impaired excretion, secondary to biliary obstruction from

cholestasis, gallstones, tumors, or strictures.

15. State the major causes of acute hepatitis.

Viruses such as hepatitis A through E viruses, Epstein-Barr virus, herpes simplex virus (HSV),

Coxsackie, and cytomegalovirus. It also can result from exposure to toxins such as ethanol,

Amanita phalloides mushrooms, carbon tetrachloride, acetaminophen, halothane, and

chlorpromazine.

16. What are the risk factors for viral hepatitis? Which can result in a carrier

state?

Hepatitis B and C are transmitted via blood and body ﬂuid exposures: sexual intercourse,

intravenous drug abuse, blood transfusions, tattoos or body piercings, hemodialysis, and

needle sticks. Hepatitis A and E are transmitted via fecal/oral exposure (i.e., foreign travel, raw

seafood ingestion, poor hygiene or sewage management, and close contact with a person

infected with hepatitis). Hepatitis A and E are often self-limited, whereas hepatitis B and C can

result in a carrier state and progress to chronic hepatitis.

17. What is the most common form of liver disease in the United States?

Alcoholic hepatitis. It is most often diagnosed by history, but the following are highly

suggestive associated ﬁndings: spider angiomas, gynecomastia, palmar erythema, ascites,

and an elevated AST and ALT in a ratio of greater than 2:1.

18. Which patients with hepatitis should be admitted?

19. What is the initial treatment of hepatic encephalopathy? What is asterixis?

Hepatic encephalopathy is the accumulation of nitrogenous waste products normally

metabolized by the liver. It comprises a spectrum of clinical presentations ranging from

lethargy to coma. In addition to supportive care, lactulose, neomycin, and a low-protein

diet are the mainstays of treatment. Lactulose reduces ammonia absorption by increasing

gastrointestinal (GI) motility and by trapping ammonia as ammonium in the stool via fecal

acidiﬁcation in the form of lactic acid; neomycin is an aminoglycoside that reduces the

bacteria that produces ammonia.

Asterixis is a clinical manifestation of moderate hepatic encephalopathy in which the hands

ﬂap (low-amplitude alternating ﬂexion and extension) when the arms are held straight and

the wrists are held in extension.

Chapter 35 LIVER AND BILIARY TRACT DISEASE252

20. What are complications of chronic liver disease to watch for in the ED?

The most common complication of cirrhotic ascites is spontaneous bacterial peritonitis

(SBP), which can present with any of the following: fever, abdominal pain, or mental status

changes. Paracentesis is diagnostic if it shows white blood cell count greater than 1000 cells/

, neutrophils greater than 250 cells/mm

, or a positive Gram stain or culture. Portal

hypertension causes the development of esophageal varices, which can lead to massive

GI bleeding. Management should focus on resuscitation, local control (balloon tamponade or

endoscopic ligation/sclerotherapy), and reduction of portal pressure (vasopressin plus

nitroglycerin, somatostatin/octreotide, and if necessary, emergent transjugular intrahepatic

portosystemic shunt). Patients with chronic liver disease are at greatly increased risk of

bleeding because of deﬁcits of the coagulation cascade proteins, platelet abnormalities, and

increased ﬁbrinolysis. Renal failure in cirrhotic patients with structurally normal kidneys

represents the hepatorenal syndrome. One study showed 38% 1-year survival in patients

with the hepatorenal syndrome.

KEY POINTS: PERITONEAL FLUID CRITERIA FOR SBP

1. White blood cell count . 1000 cells/mm

2. Neutrophil count . 250 cells/mm

3. Positive Gram stain

4. Positive culture result (gold standard)

KEY POINTS: TREATMENT OF HEPATIC ENCEPHALOPATHY

1. Supportive care

2. Lactulose, 15–30 mL PO every 6–8 hours

3. Neomycin, 0.5 gm PO every 4–6 hours

4. Low-protein diet

21. Are there any special issues to watch for in the postliver-transplant patient?

Transplant rejection is common and manifests as fever, pain, and elevated transaminases and

bilirubin. This can be treated with high-dose steroids and increased immunosuppressive

medication. Other causes of transplant dysfunction include biliary strictures, recurrence of

viral hepatitis, and vascular thrombosis. Immunosuppressive therapy can cause

nephrotoxicity, neurotoxicity, and hypertension. As with other immunosuppressed patients,

opportunistic infections, such as cytomegalovirus, Epstein-Barr virus, mycobacteria, and

Pneumocystis, and fungal infection should be considered.

WEBSITES

Hepatitis B: www.hepb.org/

Hepatitis C: http://hepatitis-central.com/

Chapter 35 LIVER AND BILIARY TRACT DISEASE 253

BIBLIOGRAPHY

1. Feldman M, editor: Sleisenger and Fordtran’s gastrointestinal and liver disease, ed 7, Philadelphia, 2002, W. B.

Saunders, pp 1065–1090.

2. Gruber PJ, Silverman RA, Gottesfeld S, et al: Presence of fever and leukocytosis in acute cholecystis. Ann

Emerg Med 28:273–277, 1996.

3. Guss DA. Liver and biliary tract. In Marx J, Hockenberger R, Walls R, editors: Rosen’s emergency medicine

concepts and clinical practice, ed 5, St. Louis, 2002, Mosby, pp 1258–1260.

4. Lum DF, Leung JW: Bacterial cholangitis. Curr Treat Opt Gastroenterol 4:139–146, 2003.

5. Shah K, Wolfe R: Hepatobiliary ultrasound. Emerg Med Clin North Am 22:661–673, 2004.

6. Sheth S, Bedford A, Chopra S: Primary gallbladder cancer: recognition of risk factors and the role of

prophylactic cholecystectomy. Am J Gastroenterol 95:1402–1410, 2000.

7. Tintinalli JE, Kelen GD, Stapczynski JS: Emergency medicine, ed 6, New York, 2004, McGraw-Hill Companies,

pp 561–564.

8. Yusoff IF, Barkun JS, Barkun AN: Diagnosis and management of cholecystitis and cholangitis. Gastroenterol

Clin North Am 32:1152–1153, 2003.

255

RENAL COLIC AND SCROTAL PAIN

CHAPTER 36

Christopher M.B. Fernandes, MD

VIII. GENITOURINARY TRACT

1. What are the most common forms of renal stones?

Calcium stones account for 80% of all renal stones: Two thirds are calcium oxalate, and

the remainder are calcium phosphate. Struvite (magnesium ammonium phosphate), uric

acid, and cystine account for 20% of renal stones.

2. List factors that predispose to stone formation.

Calcium stones

Chronic dehydration

Antacid use

Hypercalciuria

Hyperoxaluria

Acid urine

Ingestion of vitamins A, C, and D

Struvite stones: chronic infection by urea-splitting organisms

Cystine stones: cystinuria

3. What lethal conditions are sometimes misdiagnosed as renal colic?

Aortic and iliac aneurysms. A careful search for bruits and pulsatile masses is

mandatory when renal colic is suspected.

4. What clinical features help distinguish renal colic from other causes of

abdominal pain?

Renal colic usually begins abruptly, causing terrible pain in the ﬂank, costovertebral

angle, lateral abdomen, and genitals. Patients often are profoundly distressed, more so

than patients with other abdominal pathologies. Pallor, diaphoresis, restlessness, and

nausea are prominent. Renal colic causes ﬂank tenderness, but in contrast to other

causes of lateralized abdominal pain (e.g., appendicitis, diverticulitis, cholelithiasis,

and ectopic pregnancy), it produces little or no abdominal tenderness.

5. In which patients would imaging be absolutely indicated to conﬁrm the

diagnosis of renal colic?

Patients with a ﬁrst episode of renal colic

Patients in whom the diagnosis is unclear

Patients in whom a proximal urinary tract infection, in addition to a calculus, is

suspected

Elderly patients

6. What is the role of the abdominal ﬂat plate in diagnosing renal colic?

The abdominal ﬂat plate, or kidneys-ureter-bladder (KUB), is less sensitive and less

speciﬁc than the clinical examination and, by itself, has no role in the work-up of

suspected renal colic. If a stone is diagnosed on ultrasound, it may be appropriate to

view the stone on a plain ﬁlm. Subsequent radiographs may be helpful to document

stone progression.

Chapter 36 RENAL COLIC AND SCROTAL PAIN256

7. Has helical computed tomography (CT) supplanted the intravenous pyelogram

(IVP) as the diagnostic test of choice? Why or why not?

Helical noncontrast CT has replaced IVP as the preferred diagnostic test. The IVP pinpoints

stone size and location, clariﬁes the degree of obstruction, and shows ongoing renal function.

Helical CT has been shown to be 97% sensitive and 96% speciﬁc in diagnosing renal stones.

Used for this purpose, helical CT does not require intravenous contrast material and is faster

than IVP—requiring only 1 to 2 minutes of scanner time to complete a study. Even though

helical CT provides no information about renal function, this can be ascertained by a urinalysis

and serum creatinine. The marginal cost is less, and it can identify other important causes of

ﬂank pain.

8. Is pregnancy a contraindication to IVP?

Ultrasound is the investigation of choice in pregnant patients, but if ultrasound is

nondiagnostic, a limited IVP (scout ﬁlm and 20-minutes postinjection ﬁlm, preferably coned to

the area of concern) is appropriate because the risk of radiation from CT KUB is greater than

the limited exposure of plain ﬁlm radiography with this limited IVP.

9. What IVP ﬁndings suggest a renal stone?

Typical ﬁndings include a delayed, intense, and often prolonged nephrogram on the involved

side, delayed ﬁlling and dilation of the affected collecting system (hydroureter and

hydronephrosis), and an uninterrupted column of dye extending from the kidney to the

calculus. An unobstructed ureter, because it is peristaltic, does not normally appear opaciﬁed

with contrast in its entirety.

10. Why is the postvoid ﬁlm important? What other special views are helpful?

Contrast in the bladder obscures the distal ureter. The postvoid ﬁlm provides optimal

visualization of the distal ureter and the ureterovesical junction. The postvoid ﬁlm also shows

whether the bladder is emptying completely. Oblique views help to conﬁrm that a visualized

stone is in, rather than overlying, the ureter. Prone ﬁlms often provide a better view of the

ureter than do standard supine ﬁlms.

KEY POINTS: MOST COMMON FORMS OF RENAL STONES

1. Calcium stones (80%)

• Calcium oxalate: two thirds

• Calcium phosphate: one third

2. Struvite, uric acid, and cystine (20%)

11. What if the ureter is not visualized on the standard IVP?

In high-grade ureteral obstruction, contrast material may not reach the distal ureter for many

hours. If the ureter cannot be visualized at 1 hour, take a 2-hour ﬁlm. If this fails, take a

4-hour ﬁlm. The interval between ﬁlms should be doubled until adequate visualization is

achieved. It is important not to abandon the IVP until contrast material reaches the calculus.

12. Name the most common sites of ureteral stone impaction.

The ureteropelvic junction, the pelvic brim (where the ureter crosses the iliac vessels), and the

ureterovesical junction (the most narrow point in the ureter).

13. Can the likelihood of spontaneous passage be predicted based on the size

and location of the stone?

Stones reaching the distal ureter are more likely to pass than those impacting proximally.

Stones 2 to 4 mm pass 95% of the time; stones 4 to 6 mm pass 50% of the time, and stones

Chapter 36 RENAL COLIC AND SCROTAL PAIN 257

greater than 6 mm pass 10% of the time. When estimating stone size, remember that the

X-ray image is magniﬁed; the actual size is 80% of what is measured on the ﬁlms.

14. What if the imaging study is normal, but the patient still appears to have renal

colic?

Re-examine the patient carefully to ensure that you have not missed another cause of

abdominal pain and that the patient is not developing a condition requiring surgery. If the

physical examination is still compatible with renal colic, treat the patient, not the test result.

Occasional false-negative results occur with all tests, and imaging modalities may miss small

stones, but this may not be clinically relevant because small stones are unlikely to require

speciﬁc therapy. Persistent severe ﬂank pain can be caused by a leaking abdominal aortic

aneurysm (AAA).

15. Isn’t an ultrasound just as accurate as helical CT or an IVP?

Ultrasound is safe and noninvasive but is more prone to false-negative results than the other

studies. Ultrasound is sensitive for stones in the bladder and renal pelvis but often fails to

visualize those in the mid and distal ureter—the most common sites for stone impaction.

When ultrasound fails to identify a stone, however, it may show dilation of the renal collecting

system, providing evidence of ureteral obstruction.

16. List secondary signs of ureteral obstruction shown on helical CT.

Unilateral obstruction

Stranding of perinephric fat

Hydronephrosis

Nephromegaly

17. What is the soft tissue rim sign on helical CT? How is it useful?

This sign shows soft-tissue attenuation around a ureteral calculus and helps differentiate a

calculus from a phlebolith.

18. What other tests are useful in the ED in patients with renal calculi?

Urine dipsticks are sensitive for microscopic hematuria, which is present in 80% of patients

with renal colic. Urinalysis is recommended to rule out pyuria and bacteriuria. Urine culture

is indicated if symptoms, signs, or urinalysis ﬁndings suggest infection. Determination of

blood urea nitrogen (BUN), creatinine, and electrolyte levels is helpful if the patient has been

vomiting or if presence of an underlying renal disease is suspected. There is usually no need

for a more extensive metabolic work-up in the ED.

19. Why is coexistent infection a major problem?

Bacteria in an obstructed collecting system can cause abscess formation, renal destruction,

bacteremia and sepsis. The presence of infection in an obstructed ureter mandates immediate

consultation with a urologist and high-dose intravenous antibiotics.

20. Has lithotripsy supplanted percutaneous and open surgical methods of

stone removal?

Not always. Optimal therapy depends on the size, type, and location of the stone. Uretero-

scopic techniques probably are still preferable for lower ureteral stones. Extracorporeal

shock wave lithotripsy (ESWL) is optimal for stones 2 cm in size, particularly those in the

renal pelvis. Percutaneous stone removal techniques are indicated for larger stones, when

there is obstructive uropathy, and when less invasive techniques have failed. For some

stones, a combination of ESWL followed by percutaneous instrumentation is optimal.

Some large stones still require open surgery. The method of removal is best determined

by a urologist. Of note, newer technologies for treatment have led to an increased

frequency of procedural interventions, with an overall cost increase attributable to

stones compared to the pre-ESWL era.