How do you assess rebound tenderness for appendicitis?

4 Psoas Sign

The inflamed appendix may lie against the right psoas muscle, causing the patient to shorten that muscle by drawing up the right knee. To elicit the psoas sign, the patient lies down on the left side and the clinician hyperextends the right hip. Painful hip extension is the positive response.7,11

5 Obturator Sign

The obturator sign is based on the same principle as the psoas sign, that stretching a pelvic muscle irritated by an inflamed appendix causes pain. To stretch the right obturator internus muscle and elicit the sign, the clinician flexes the patient’s right hip and knee and then internally rotates the right hip.7,11

1 Individual Findings (See EBM Box 52.2)

All of the findings in EBM Box 52.2 apply to patients with suspected appendicitis (indeed the most common cause of peritonitis in these studies was appendicitis). Additional special tests that further increase the probability of appendicitis are McBurney point tenderness (LR = 3.4), positive Rovsing sign (LR = 2.3), and positive psoas sign (LR = 2). The only special finding decreasing the probability of appendicitis (other than absence of right lower quadrant tenderness) is the absence of McBurney point tenderness (LR = 0.4).

McBurney point tenderness may have even greater accuracy if every patient’s appendix were precisely at the McBurney point, but radiologic investigation reveals that the normal appendix sometimes lies a short distance away.82 In one study of patients with acute abdominal pain, clinicians first located the patient’s appendix using handheld ultrasound equipment. Maximal pinpoint tenderness over this “sonographic McBurney point” had superior diagnostic accuracy for detecting appendicitis (sensitivity = 87%, specificity = 90%, positive LR = 8.4, negative LR = 0.1).83

In contrast to a long-held traditional teaching, giving analgesics to patients with acute abdominal pain does not change the accuracy of individual signs or reduce the clinician’s overall diagnostic accuracy.84

Rectal tenderness (see EBM Box 52.1) and the obturator sign (see EBM Box 52.2) were diagnostically unhelpful in these studies. Nonetheless, a rectal examination should still be performed to detect the rare patient (2% or less) with a pelvic abscess and rectal mass.39,41

Diagnostic Approach

Once a thorough history and physical examination have been completed, laboratory findings and integration of all data can help confirm the diagnosis. Laboratory tests should include a complete blood count, urinalysis, basic metabolic panel, and pregnancy test for all female patients of childbearing age. Leukocytosis ranging from 10,000 to 18,000 cells/mm3 and an elevated absolute neutrophil count are common in patients with simple early appendicitis. White blood cell counts greater than 18,0000 cells/mL3 correlate with perforated appendicitis or appendiceal abscess. A urinalysis helps to rule out a urinary tract infection because bacteriuria is not typically seen in patients with appendicitis. A basic metabolic panel may reveal electrolyte abnormalities derived from anorexia, vomiting, and secondary dehydration. A pregnancy test is important to rule out an ectopic pregnancy in all females of childbearing age.

The combination of findings derived from the history and physical examination and results from the initial laboratory tests can usually be enough to confirm the diagnosis or suspicion of acute appendicitis, particularly in the most common and typical cases. The most typical presentation will be a young adolescent male with a 1- to 2-day history of periumbilical pain radiating to the right lower quadrant with rebound positive or negative Rovsing sign and mild leukocytosis. More delayed presentations, 4 to 5 days from the beginning of pain, are characterized by the presence of fever, tachycardia, rebound, and positive Rovsing sign, and occasionally a right lower quadrant mass may be felt, suggesting the presence of an abscess or phlegmon. Less commonly, late presentations progress to diffuse peritonitis characterized by diffuse abdominal pain and a more severe systemic inflammatory response.

Other tools can be used to help confirm the diagnosis. Findings from history, physical examination, and laboratory tests can also be used to calculate the Alvarado score. This score is based on eight data points and was developed to help confirm the diagnosis of acute appendicitis using clinical and initial laboratory findings (Table 42-1). Higher scores are directly associated with higher likelihood of appendicitis; scores lower than 5 are unlikely to represent appendicitis, whereas those higher than 6 or a score of 10 are considered consistent and highly consistent with appendicitis, respectively.

Special considerations should be given to the elderly, young children, and the pregnant. Both the elderly and children usually present later with longer duration of prehospital symptoms. In addition, findings in these populations are somewhat atypical. In older patients, periumbilical migratory pain is almost always absent, and pain located in the right lower quadrant is reported in only 80% of cases. The accuracy of the Alvarado score also declines in this population, with less than 50% of patients having scores higher than 7. This uncommon presentation is associated with more advanced disease, including higher rates of perforations and abscess formation, which in combination with more associated comorbidities result in worse overall outcomes, including longer lengths of stay and higher rates of postoperative complications and death. In children younger than 5 years old, the inability to give an accurate history often limits an earlier diagnosis, which can result in similar patterns of diagnosis, treatment, and outcomes as those observed in the elderly. In the pregnant patient, as the gravid uterus enlarges the appendix moves cephalad (Figure 42-3). This is an important consideration that changes the location of pain as well as the surgical approach when the diagnosis is confirmed.

Finally, other differential diagnoses must be considered when evaluating patients with right lower quadrant abdominal pain, including urinary tract infections, diverticulitis, perforated ulcer, ectopic pregnancy, ruptured ovarian cyst, ovarian torsion, pelvic inflammatory disease, testicular torsion, inguinal hernia, Meckel's diverticulum, Crohn's enteritis, gastroenteritis, and complications derived from a colonic or small bowel tumor.

When using the described approach to work up patients with suspected acute appendicitis, a false-positive diagnosis can still be made. This results in negative appendectomy, which has been reported to occur in 15% of patients, as reported by both clinical and population-level analyses. The negative appendectomy rate is higher for females (22% versus 9% for males) and even higher for women of reproductive age (up to 26%). A negative appendectomy rate of 10% to 15% is generally accepted, considering that a low threshold for operation can avoid the complications derived from delayed diagnosis including perforation, and this strategy is additionally supported by a low cost to the patient and the healthcare system.

A more thorough workup including the use of imaging studies (CT or ultrasound) has been advocated with the primary goal of improving the accuracy of the diagnosis. Two prospective studies have shown a decrease in the number of unnecessary admissions and appendectomies with CT. However, a longitudinal population-level study suggested that despite the introduction of ultrasound and CT scanning, the rates of negative appendectomies have remained unchanged over time, arguing against a routine use of these diagnostic strategies. Imaging studies should be considered selectively, when the diagnosis is unclear and in patients with higher risk of negative appendectomy. CT scan is the preferred diagnostic test, although ultrasound is a good alternative particularly in children and thin patients, as well as in pregnant women or women of childbearing age, to delineate uterine and/or ovarian pathology.

Physical Examination

Typical physical signs of acute appendicitis include localized tenderness in the right lower quadrant, muscle guarding, and rebound tenderness. Cutaneous hyperesthesia, right-sided pelvic tenderness on rectal examination, and the presence of a psoas or obturator sign occur less frequently and tend to be highly dependent on the examiner. Although often the temperature is normal, fever up to 38° C or higher may occur. In the usual case of acute, nonperforated appendicitis, higher fever occurs infrequently.

CLINICAL FEATURES

A detailed history and careful physical examination remain cornerstones of the diagnosis of acute appendicitis. Although no single item of the history, in isolation, allows the diagnosis to be made reliably, combination of the classic symptoms and the typical progression of symptoms coupled with right lower quadrant tenderness allows good diagnostic accuracy. In the classic presentation of acute appendicitis, patients first note vague, poorly localized epigastric or periumbilical discomfort, which typically is not severe and often is attributed to “gastric upset.” Patients commonly report feeling that a bowel movement should make the pain better, a sensation known as the downward urge.26

Diarrhea sometimes is seen early on with appendicitis, but this is not common. Within 4 to 12 hours of the onset of pain, most patients also note nausea, anorexia, vomiting, or some combination of these three symptoms. The nausea usually is mild to moderate, and most patients have only a few episodes of emesis. If vomiting is the major symptom, the diagnosis of appendicitis should be questioned. Likewise, emesis that occurs before the onset of pain should suggest other diagnoses.27 Many patients report a mild fever or chills; high fevers or significant rigors are uncommon. The patient's abdominal pain typically increases in intensity, and a characteristic shift in the pain to the right lower quadrant occurs over 12 to 24 hours. The character of the pain becomes achy and more localized. Localization of the pain to the right lower quadrant is a valuable finding when present and occurs in more than 80% of patients with appendicitis.27

On physical examination, most patients appear slightly ill. Tachycardia is uncommon with simple appendicitis, but it may be seen with complicated appendicitis. Most patients with simple appendicitis have a temperature less than 100.5°F; temperature greater than 100.5°F is most often associated with perforated or gangrenous appendicitis.17 Patients with appendicitis, like other patients with peritonitis, tend to lie still rather than move about. Right lower quadrant tenderness and rigidity, both voluntary and involuntary, are common findings. Localized right lower quadrant tenderness is an important finding when present, but its absence does not rule out appendicitis. A variety of methods exist to elicit localized right lower quadrant peritonitis, including the cough sign (the presence of point tenderness with a cough), percussion tenderness, and formal elicitation of rebound tenderness. Although all of these techniques are reasonably sensitive, one small study showed rebound tenderness to be the most accurate predictor of the localized peritonitis associated with appendicitis.28

Additional findings that may be helpful in diagnosing appendicitis include the psoas sign, the obturator sign, Rovsing's sign, and rectal tenderness. The psoas sign is sought by having a supine patient actively flex the right hip against resistance, or by the examiner flexing and extending the patient's right hip with the patient in the left lateral decubitus position. Pain with either of these maneuvers is thought to result from irritation of the underlying psoas muscle by an inflamed retroperitoneal appendix. The obturator sign is elicited by internally and externally rotating the flexed right hip. Pain is thought to arise when the inflamed pelvic appendix irritates the adjacent obturator internus muscle. Rovsing's sign is the finding of right lower quadrant pain during palpation of the left side of the abdomen or when left-sided rebound tenderness is elicited. All of these findings are valuable when present, but their absence does not exclude appendicitis.27

Appendicitis can be easy to diagnose when the presentation is typical, but a typical presentation is encountered in only 50% to 60% of cases. An atypical presentation of appendicitis occurs for a variety of reasons. The classic migration of periumbilical pain to the right lower quadrant is thought to occur when the parietal peritoneum in the right lower quadrant becomes irritated by the inflamed appendix. In cases of retrocecal or pelvic appendicitis, this site might not become irritated. Atypical presentations of appendicitis are particularly common in patients who are at the extremes of age, pregnant, or immunosuppressed, including those with acquired immunodeficiency syndrome (AIDS) and a low CD4 cell count.

Appendicitis in infants and young children remains a difficult diagnostic challenge because of difficulties in obtaining an accurate history. In young patients, the characteristic history of pain is difficult to elicit, and nonspecific findings of vomiting, lethargy, and irritability tend to predominate. Physical examination is difficult to perform because of poor patient cooperation and because localized right lower quadrant tenderness is found in less than 50% of patients.29 In addition, the characteristic laboratory findings often are not present. Leukopenia is as common as leukocytosis in young infants.30 As a result, errors in diagnosis are common, and the frequency of complicated appendicitis is as high as 40% to 70%.31

The diagnosis of appendicitis in elderly patients also may be a challenge. In the elderly, the classic pattern of pain migration, right lower quadrant tenderness, fever, and leukocytosis are observed in only 15% to 30% of cases.30,32 Older patients also tend to present to medical attention in a delayed time frame relative to younger patients. For all of these reasons, the complication and perforation rates can be as high as 63% in patients older than 50 years.33

The presentation of appendicitis during pregnancy also is associated with an atypical clinical presentation, particularly in the later stages of pregnancy. In one series, only 57% of pregnant women with appendicitis had the classic progression of pain.34 Nausea and vomiting tend to be more common in pregnant women with appendicitis, but they also are common occurrences during normal pregnancy. Fever and leukocytosis are less commonly seen in pregnant woman than in other patient groups, and the value of leukocytosis is obscured by the physiologic leukocytosis of pregnancy. Although right-sided abdominal pain and tenderness are found in more than 90% of pregnant women with appendicitis, pain is located in the right lower quadrant only 75% of the time.34

Immunocompromised patients in general, and patients with AIDS in particular, represent a challenging group in which to diagnose appendicitis. Abdominal pain is reported in 12% to 45% of AIDS patients with appendicitis. The range of diagnoses responsible for this pain is significantly greater than in patients without HIV and includes opportunistic infections and malignancies, although in most cases, the pain is related to a diagnosis not associated with HIV.35 Research suggests that appendicitis occurs more often in HIV-infected patients than in HIV-negative patients, with as much as a four-fold increase in incidence.36 Although patients with AIDS usually present with the classic symptoms of appendicitis, there often is a history of chronic abdominal pain. Diarrhea also is a more common presenting symptom of appendicitis in HIV-positive patients, and leukocytosis is relatively uncommon. Declining CD4 counts are associated with delays in presentation to medical attention and increased perforation rates.37 Despite the challenges of diagnosing appendicitis in patients with HIV, the surgical outcomes with appropriate treatment are quite good; the largest series to date had no mortalities and a 13% complication rate, which is comparable to outcomes in patients without HIV.37

Physical examination

As with most disease processes, much can be learned before the patient is touched. Children with appendicitis usually lie in bed with minimal movement. A squirming, screaming child rarely has appendicitis. An exception to this is the child with retrocecal appendicitis and subsequent irritation of the ureter presenting with pain similar to renal colic. Older children may limp or flex the trunk, whereas infants may flex the right leg over the abdomen. A recall of localized pain elicited by bumps in the road on the ride to the hospital is helpful.

Before starting palpation of the abdomen, it is useful to ask the child to point with one finger to the location of the abdominal pain. With the knees bent to relax the abdominal muscles, gentle palpation of the abdomen should begin at a point away from the location of perceived pain. Palpating the abdomen in an area remote from the site of pain may elicit tenderness in the right lower quadrant (Rovsing sign of referred pain), indicating peritoneal irritation. Younger children may be more cooperative if their hand or the stethoscope is used for palpation. The stethoscope can have several roles in the evaluation of a patient who potentially has appendicitis, the least important of which is auscultation. Although patients often have diminished or absent bowel sounds, this is not uniform and auscultation of the abdomen is of little benefit. However, auscultation of the chest to examine for lower respiratory infection is useful because right lower lobe pneumonia can mimic appendicitis. Cutaneous hyperesthesia, a sensation derived from the T10 to L1 nerve roots, is often an early although inconsistent sign of appendicitis. Lightly touching the patient with the stethoscope creates this uncomfortable sensation.

Localized tenderness is essential for diagnosis and is noted either on palpation or percussion. Tenderness can be mild and even masked by more generalized abdominal pain, especially during initial stages. The McBurney point is the most common location. Retrocecal appendicitis may be detected by tenderness midway between the twelfth rib and the posterior superior iliac spine. Pelvic appendicitis produces rectal tenderness. A child with malrotation will have localized tenderness that corresponds to the position of the exudative drainage from the inflamed appendix.

As the disease progresses to perforation, peritonitis ensues. The pattern of pain depends on the location of the appendix. Perforation may result in temporary relief of symptoms as the pain of the distended viscus is relieved. Initially, peritonitis is reflected as local muscular rigidity. This progresses from simple involuntary guarding to generalized rigidity of the abdomen. Other signs include rigidity of the psoas muscle (demonstrated by right hip extension or raising the straight leg against resistance) or of the obturator muscle (demonstrated by passive internal rotation of the right thigh), both of which indicate irritation of these muscles due to retrocecal appendicitis. Other tests of peritoneal inflammation such as rebound tenderness are seldom necessary for diagnosis and cause unnecessary discomfort.

The routine use of rectal examination in the diagnosis of appendicitis has recently been questioned.52–54 Pain during this examination is nonspecific for appendicitis. If other signs point to appendicitis, the rectal examination is unnecessary. However, it may be a helpful diagnostic maneuver in questionable cases such as when a pelvic appendix or abscess is suspected or when uterine or adnexal pathologic conditions are being considered.

If appendicitis is allowed to progress, two results are possible: (1) diffuse peritonitis and shock will occur or (2) the infection will become isolated and an abscess will form. Diffuse peritonitis is more common in infants, probably because of the absence of omental fat. Older children and teenagers are more likely to have an organized abscess. The physical examination in cases of an organized abscess reveals a boggy, tender mass over the abscess.

A frequently unreported but critical aspect of the evaluation is serial examinations done by the same person. The safety and efficacy of serial observation was first reported by White in 197555 and has since been reinforced by other studies. Surana56 reported a prospective study showing no increase in morbidity with appendectomy after active observation in a hospital compared with urgent appendectomy. When the diagnosis is unclear, serial abdominal examinations permit the physician to decrease the number of unnecessary laparotomies without increased risk to the patient.

1 What is the classic presentation of acute appendicitis?

Periumbilical pain that migrates to the right lower quadrant (RLQ) in a patient who is anorexic. Associated symptoms include: nausea, vomiting, and bowel changes.

2 What is the pathophysiology of appendicitis?

The appendix is susceptible to luminal obstruction, via lymphoid hyperplasia, a retained fecalith, tumor, foreign body, or kink. Any of these processes may result in lymphatic and venous obstruction that increases intraluminal pressure and causes distention of the appendiceal lumen. Consequently, an acute inflammatory response develops that leads to ischemia, bacterial overgrowth and eventually necrosis. Unless surgically removed, the gangrenous appendix will perforate, releasing the appendiceal contents into the peritoneal cavity. Subsequently a phlegmon, intraperitoneal abscess, or local peritonitis develops.

3 What is the mechanism of the periumblical pain?

The intestines are insensitive to touch or inflammation unless the enclosing peritoneum is involved. Epigastric pain results from a distended section of intestine. This pain is referred along midline.

4 Where is McBurney's point?

One third the distance between the anterosuperior iliac spine and the umbilicus.

5 What is McBurney's point?

The point of maximal tenderness in acute appendicitis. It results from local inflammation of the parietal peritoneum.

6 Was McBurney a cop from Boston?

Probably. Another McBurney was a surgeon from New York who, in collaboration with a surgeon named Fitz, coined the term appendicitis in classic papers published in 1886 and 1889.

7 What are the typical laboratory findings of a patient with appendicitis?

▪

White blood cell (WBC) count: 12,000 to 14,000

Negative urinalysis results (no WBCs)

Negative pregnancy test result

8 What layers does the surgeon encounter on exposing the appendix through a Rockey-Davis incision?

Skin, subcutaneous fat, aponeurosis of the external oblique muscle, internal oblique muscle, transversalis abdominus muscle, tranvsersalis fascia, and peritoneum.

9 Other possible signs in appendicitis include:

Rovsings sign: pain in the RLQ with palpation of the left lower quadrant (LLQ).

Dunphy's sign: increased pain with coughing (a cough jostles the inflamed peritoneum).

Psoas sign: pain on passive extension of the right thigh. It is present when the inflamed appendix is retrocecal and overlying the right psoas muscle.

Obturator sign: pain on passive internal rotation of the hip when the right knee is flexed. It is present when the inflamed appendix is in contact with the obturator internus muscle.

10 Who was Rockey-Davis?

Rockey-Davis was a pair of surgeons—A.E. Rockey and G.G. Davis—who developed RLQ transverse, muscle-splitting incisions that extend into the rectus sheath.

11 What is the blood supply to the appendix and right colon?

The ileocolic and right colic arteries, which come off the superior mesenteric artery.

12 Does surgery for appendicitis involve a risk of mortality?

No surgical procedure is devoid of risk.

Mortality rateNonperforated appendix<0.1%Perforated appendix≈5.0%

13 What patient groups are at higher risk of death from perforated appendicitis?

1

Very young patients (younger than 2 years).

Elderly patients (older than 70 years) who exhibit diminished abdominal innervation and present late.

Diabetic patients, who present late because of diabetic visceral neuropathy.

Patients taking steroids; steroids mask everything.

14 What is a “white worm”?

A normal appendix.

15 What is the differential diagnosis of right lower quadrant pain?

Meckel's diverticulumTubo-ovarian abscess (TOA)DiverticulitisPelvic inflammatory disease (PID)Ectopic pregnancyCarcinoid tumorCrohn's diseaseCholecystitisOvarian torsionRuptured ovarian cyst

16 What is an acceptable negative appendectomy rate?

This is a controversial topic currently being debated in surgical literature. Traditionally up to a 20% negative appendectomy rate was considered acceptable. Now with the adjunct of imaging (ultrasound [US] and computed tomography [CT]) lower negative rates are expected.

17 What is the role of imaging in the diagnosis of acute appendicitis?

US and CT can be both negatively and positively helpful. They may eliminate alternative diagnoses such as ectopic pregnancy or TOA when a perfectly normal right fallopian tube and ovary is seen. They may establish the diagnosis when an inflamed, edematous appendix is visualized. CT is particularly useful in visualizing periappendiceal tissue and may reveal that the appendix has already perforated by showing a phlegmon or abscess.

18 What are sonographic and CT findings suggestive of appendicitis?

1

An appendix of 7 mm or greater in anteroposterior diameter.

The presence of an appendicolith.

Periappendiceal fluid or mass.

19 Is laparoscopic appendectomy replacing the traditional approach?

In the hands of a skilled laparoscopic surgeon both the normal appendix and the inflamed, perforated appendix can be removed safely with the laparoscope. Also when the diagnosis is in question, the laparoscope can be used to help identify the correct pathology. Occasionally conversion from laparoscopic to open appendectomy is indicated.

Key Points: Appendiceal Carcinoid

Sixty percent of carcinoid tumors occur in the appendix; 0.03% of appendectomies reveal incidental carcinoid.

This malignant but slow tumor spreads to lymph nodes, liver, and right heart.

If tumor size is <2 cm and does not involve the base of the appendix, appendectomy alone may suffice; however, bowel should be assessed because of 30% chance of synchronous lesion.

If tumor size is >2 cm or involves the base of the appendix, right hemicolectomy is necessary.

20 What is a Meckel's diverticulum?

Meckel's diverticulum is a congenital omphalomesenteric mucosa remnant that may contain ectopic gastric mucosa. It is found in 2% of the population, 2 feet upward from the ileocecal valve. It becomes inflamed in 2% of patients (i.e., the rule of 2's).

21 Can chronic diverticulitis masquerade as appendicitis?

Yes. Fifty percent of patients aged 50 years and older have colonic diverticula. The appendix is just a big cecal diverticulum. Thus, it makes sense that appendicitis and diverticulitis should look, act, and smell alike.

22 Can a woman with a negative pregnancy test present with an ectopic pregnancy?

Yes. The fallopian tube must be inspected for a walnut-sized lump. Appropriate surgical therapy is a longitudinal incision to “shell out” the fetus with subsequent repair of the tube. This approach (as opposed to salpingectomy) is designed to preserve fertility. Methotrexate also may precipitate spontaneous evacuation.

23 Can Crohn's disease initially present as appendicitis?

Yes; this presentation is typical. Crohn's disease is boggy, edematous, granulomatous inflammation of the distal ileum. Traditional surgical dictum suggests that it is appropriate to remove the appendix in patients with Crohn's disease unless the cecum at the appendiceal base is involved.

24 Is it possible to confuse appendicitis with a TOA?

Of course. An ovarian abscess buried deep in an inflamed, edematous, matted right adnexa can be treated successfully with intravenous (IV) antibiotics alone. Do not drain pus into the free peritoneal cavity; this will only make the patient sicker.

25 Can pelvic inflammatory disease resemble appendicitis?

PID can look exactly like appendicitis except for a positive “chandelier sign.” On pelvic examination, manual tug on the cervix moves the inflamed, painful adnexae, and the patient hits the chandelier. Patients with PID should be treated with antibiotics (either orally or intravenously, depending on how sick the patient is).

26 How does one deal with an appendiceal carcinoid tumor?

Carcinoid tumors may present anywhere along the gastrointestinal (GI) tract; 60%, however, are in the appendix. An obstructing carcinoid tumor, much like a fecalith, can lead to appendicitis; and in 0.3% of appendectomies, carcinoid tumors are the culprit. Most carcinoid tumors are small (<1.5 cm) and benign; 70% are located in the distal appendix. They are effectively treated with appendectomy alone. A large carcinoid tumor (>2.0 cm) at the appendiceal base, especially with invasion into the mesoappendix, must be considered malignant and mandates a right hemicolectomy.

27 Can appendicitis be mistaken for acute cholecystitis?

Occasionally, yes. Both entities reflect acute, localized, intraperitoneal inflammation. Laboratory studies may be identical: WBC count of 12,000 to 14,000, negative urinalysis result, and negative pregnancy test result. Thus, if one is thinking “appendicitis,” the major difference may be only right upper quadrant pain versus RLQ pain. Laparoscopic cholecystectomy is possible for acute cholecystitis, but conversion to an open procedure should be more frequent.

Websites

www.websurg.com (lectures, videos, excellent photos of laparoscopic surgery)

www.pmppals.org/appendiceal_carcinoid.htm

Diagnosis

The classic history of appendicitis is one of dull periumbilical pain followed by anorexia and then localized pain developing in the right lower quadrant (RLQ). Nausea and then vomiting generally precede localization of pain to the right lower quadrant, although nausea is present at some time during the clinical course in 90% of patients with appendicitis (Table I). The absence of anorexia makes the diagnosis of appendicitis questionable and the “hamburger sign” (asking the patient if he or she would want to eat a favorite food) is one way to assess this.

TABLE I. Common Signs and Symptoms of Appendicitis

Symptoms Abdominal pain, periumbilical RLQ pain Anorexia Nausea/vomiting Pain migrationSigns RLQ tenderness Guarding Rebound tenderness Low-grade fever Elevated white blood cell count Rovsing's sign (see text for description) Psoas sign Obturator sign Dunphy's sign

The usual order of events is as follows: epigastric or periumbilical pain, anorexia, nausea, vomiting, RLQ tenderness, fever (usually low grade), and leukocytosis. Since the innervation of the appendix migrates to the right lower quadrant from autonomic efferents associated with the spinal cord around T10 and the abdominal organs lack direct innervation by pain fibers, dull pain is initially felt around the umbilicus. As inflammation progresses, the parietal peritoneum in the right lower quadrant becomes more irritated, resulting in localized pain. The pain becomes constant as the lumen of the appendix develops increasing distension and ischemia results. Approximately 40% of patients will present with atypical pain. Perforation is rare if symptoms have been present for less than 24 h.

The differential diagnosis of abdominal pain that can mimic appendicitis is broad (Table II). Conversely, because of its potential for variable presentation, appendicitis should always be considered when evaluating any acute abdominal pain. Tenderness to percussion demonstrates peritoneal irritation, as does guarding and pain with motion. Occasionally, a tender mass, which is either the distended, inflamed appendix or an appendiceal abscess, can be palpated in the right lower quadrant. Hyperesthesia of the skin overlying the right lower quadrant is an occasional finding in the distribution of the 10th through 12th dorsal spinal segments and 1st lumbar spinal segment.

TABLE II. Differential Diagnosis of Acute Appendicitis

Gastrointestinal Cholecystitis Inflamed or leaking duodenal ulcer Crohn's disease Cecal cancer Inflamed Meckel's diverticulum Intestinal obstruction Diverticulitis with or without abscess Gastroenteritis Typhlitis Omental torsion Perforated viscus Pancreatitis IntussusceptionMusculoskeletal Psoas abscess Rectus sheath hematomaUrologic Ureteral stone Urinary tract infection Pyelonephritis Nephrolithiasis Perinephric abscess Hydronephrosis ProstatitisGynecologic Tubo-ovarian abscess Ectopic pregnancy Endometriosis Salpingitis Ruptured ovarian cyst Ovarian torsion Ruptured follicular cyst (mittelschmerz) Pyosalpinx Pelvic inflammatory diseaseSystemic Diabetic ketoacidosis Porphyria Sickle cell disease Henoch-Schonlein purpuraTropical areas Amebic typhlitis Malaria Leaking liver abscess Yersinia infection

Various physical signs are often present in appendicitis. The psoas sign elicits pain on passive extension of the right thigh with the patient lying on the left side since the inflamed appendix overlies the psoas muscle. Pain on passive internal rotation of the flexed thigh is called the obturator sign. Additional findings include Rovsing's sign, which is pain in the right lower quadrant on palpation of the left lower quadrant, and Dunphy's sign, which is pain on coughing. The presence of these signs helps to confirm the diagnosis, but they are by no means sensitive or specific. Tenderness on rectal exam may be helpful in making the diagnosis if there is an abscess or pelvic appendicitis. Bimanual/speculum exam should be performed in women to evaluate for gynecologic causes of pain such as pelvic inflammatory disease.

Laboratory tests often demonstrate an elevated white blood cell count and/or bandemia. The BUN to creatinine ratio may be elevated if the patient is dehydrated from decreased intake and vomiting. Urine analysis is useful in assessing for ureteral stones, which produce hematuria, or urinary tract infections (bacteruria, pyuria). Local inflammatory reaction to appendicitis, however, can also give white blood cells and red blood cells in the urine. A test for human chorionic gonadotropin in the urine should be checked in all women of childbearing age, both to exclude normal or ectopic pregnancy as a cause of pain and to tailor diagnostics and treatment if necessary.

Although the diagnosis of appendicitis is generally made on the basis of history and physical exam, radiologic studies are effective tools in equivocal diagnoses. Plain film rarely contributes to the diagnosis, although findings in appendicitis can include a visible fecalith, localized ileus, loss of the peritoneal fat stripe from the right lower quadrant inflammatory process, and right psoas muscle deformation from the patient splinting away from right lower quadrant pain. Ultrasound and computed tomography (CT) scan are the most effective methods of elucidating a diagnosis of appendicitis. On ultrasound, a positive study shows a distended appendix that measures greater than 6 mm in diameter, is noncompressible, and is tender with probe compression. The transverse images show a “target” or “bullet” sign, which is the side view of the distended, thickened appendix (Fig. 1). A normal appendix must be seen to rule out appendicitis. Depending on the operator, appendiceal ultrasound has a sensitivity of approximately 85% and a specificity of 90%.

The use of CT images to diagnose appendicitis has greatly affected management of suspected appendicitis. Although the initial studies with CT-diagnosed appendicitis were performed with rectal contrast, Brigham and Women's Hospital favors a standard abdominal /pelvic CT scan with oral and intravenous contrast. If the radiologist is unable to make or exclude the diagnosis with the initial scan and there is a high index of suspicion, a rectal contrast CT scan can then be performed. An advantage of this technique is contrast-aided imaging of the entire abdomen for other possible diagnoses. Positive studies show a thick-walled, distended, non-contrast-filling appendix, periappendiceal inflammation, fluid collections or abscess, and often, an appendicalith (Fig. 2). If contrast fills the appendix and there is no evidence of surrounding inflammation, the diagnosis is considered to be excluded.

Depending on the radiologist, appendiceal CT scans have a sensitivity of approximately 90–99% and a specificity of 97%. Multiple studies have demonstrated the cost effectiveness of CT when used in equivocal cases of appendicitis. In general, patients with a questionable history and physical who would have been observed closely in the past are now undergoing CT scans and either being discharged or taken to the operating room. As clinicians become more comfortable with using CT scans as a diagnostic tool, the rate of negative exploration is expected to decrease.

Nongastrointestinal Causes

Numerous medications can cause vomiting either by direct gastric irritation or the stimulation of nausea. Chronic nonsteroidal anti-inflammatory drugs can cause a severe gastritis that leads to ulceration and hematemesis. Common antibiotics, particularly amoxicillin–clavulanic acid and erythromycin, can cause both vomiting and diarrhea as unwanted side effects. Chemotherapeutic agents and radiation are notorious for causing nausea and vomiting. Some children develop vomiting before receiving these therapies as a behavioral response secondary to prior negative experiences.

There are several neurologic causes of vomiting. Migraine headaches can affect even young children, who may be unable to identify the location of pain, aura, or scotoma. Caregivers note only the vomiting. Motion sickness can cause significant nausea and vomiting and often exists in families with a history of migraines. Cyclic vomiting presents primarily with vomiting and abdominal pain, but children may also report headache or vertigo. Cyclic vomiting sometimes responds to cyproheptadine, antiemetics, or intravenous fluids until the episode has passed. Familial dysautonomia is an autosomal recessive autonomic neuropathy that can result in vomiting crises, along with excessive sweating, rashes, ataxia, seizures, and irritability.

Increased intracranial pressure may initially present with nausea and headache. If the intracranial pressure is from an expanding mass such as a tumor, hydrocephalus, or vascular malformation, intractable vomiting can develop. Accompanying features may include headache and visual changes. A headache that awakens a child from sleep, is constant, or worsens with Valsalva maneuvers is worrisome. Blurry vision, diplopia, and visual field cuts are also suggestive of increased intracranial pressure. Idiopathic intracranial hypertension can stimulate nausea and vomiting as well as cause headache. It has a higher incidence in obese females and in teenagers on acne medications such as isotretinoin, tetracycline, or minocycline. Subdural hematomas from accidental or nonaccidental trauma, as well as cerebral edema from trauma or infection such as meningitis, may present with vomiting before other neurologic signs are seen. Vomiting can also occur during or after a seizure or following a concussion.

Otitis media and benign paroxysmal positional vertigo (BPPV) are two otologic causes of vomiting. Otitis media can disturb the vestibular system, and the vomiting improves with treatment of the infection. In older patients, BPPV can be diagnosed by using the Dix-Hallpike maneuver to elicit vertical-torsional nystagmus characteristic of BPPV. The symptoms often respond to physical maneuvers to reposition loosened particles from the utricular macula that float in the long arm of the posterior semicircular canal and stimulate the sensation of vertigo. In young children with BPPV, cyproheptadine and other antihistamines are sometimes helpful. Sinusitis can also stimulate vomiting secondary to persistent postnasal drip. Posterior oropharyngeal bleeding from epistaxis or bleeding after a tonsillectomy and adenoidectomy can lead to hematemesis.

Infectious causes of vomiting are numerous, with the majority being viruses. Norovirus, rotavirus, enterovirus, and adenovirus often cause self-limited episodes of emesis. Bacterial causes include but are not limited to Staphylococcus aureus (toxin mediated), Bacillus cereus, Shigella, Salmonella, Escherichia coli, Yersinia enterocolitica, and Campylobacter jejuni. Group A streptococcal pharyngitis often causes vomiting in children. Appendicitis presents with nausea, vomiting, anorexia, fever, and periumbilical pain that migrates to the right lower quadrant. Children with peritonitis from a perforation or those with severe inflammation often demonstrate rebound, guarding, or a Rovsing sign on examination. Appendicitis in young children can be difficult to diagnose because they may have no signs of anorexia and appear to have only diffuse abdominal pain. Viral or bacterial meningitis also stimulates nausea andvomiting. A postviral gastroparesis can delay gastric emptying and cause vomiting and decreased appetite that can last for months. Parasitic infections, such as ascariasis, can also cause obstructions leading to vomiting.

The respiratory system is occasionally responsible for emesis. Children with pertussis can have such violent paroxysms of coughing that they have post-tussive emesis. The respiratory signs of lower lobe pneumonia in children can be overshadowed by such severe abdominal pain and emesis that children sometimes undergo evaluations for appendicitis that reveal pneumonia on the higher cuts of an abdominal computed tomography scan. Bronchiolitis or excessive crying can cause aerophagia, which can stimulate emesis.

Cardiovascular causes of vomiting are generally related to arrhythmia or heart failure. Supraventricular tachycardia in a young infant can cause irritability and feeding intolerance. A child with heart failure secondary to a ventricular septal defect or other congenital or acquired cardiac abnormality can also have emesis or feeding intolerance. Vomiting can also be a sign of heart transplant rejection.

The genitourinary system can cause vomiting in several ways. Pyelonephritis, nephrolithiasis, ureteropelvic junction obstruction, and renal insufficiency can all present at various ages with emesis. Torsion of the ovary or testis causes severe pain along with emesis in some cases. Nausea from pregnancy is a cause of vomiting not to be overlooked in teenaged girls.

The endocrine system can be implicated in vomiting in several ways. Children with diabetic ketoacidosis begin to have intractable vomiting as they become more ketotic and acidotic, leading to further dehydration and worsening of their condition. Vomiting is a prominent feature of salt-wasting congenital adrenal hyperplasia, which should be suspected in a female infant with any sign of virilization. Male infants with this form of congenital adrenal hyperplasia usually have normal genitals, and their condition may be mistaken for gastroesophageal reflux or pyloric stenosis. Addison's disease can present with vomiting during a crisis.

Metabolic and mitochondrial diseases should also be considered in a young child or infant with persistent vomiting. Hypercalcemia, hypokalemia, hypoglycemia, and hyperammonemia can all cause emesis. Urea acid cycle defects such as ornithine transcarbamylase deficiency generally present in newborns with emesis, lethargy, coma, and death if not recognized and treated aggressively. Even those with partial defects may have more exaggerated vomiting illnesses in childhood. Aminoacidopathies such as tyrosinemia can present with vomiting in children aged 2 weeks to 1 year. Organic acidopathies such as maple syrup urine disease, isovalericacidemia, mevalonicacidemia, propionicacidemia, and methylmalonicacidemia present with vomiting in infancy. Lactic acidosis, fatty acid oxidation defects, particularly medium-chain acyl-CoA dehydrogenase deficiency, glycogen storage disease, and galactosemia have vomiting as a primary presenting feature as well. Porphyria can present with periods of vomiting, change in mental status, or rash, depending on the subtype. Mitochondrial diseases are often associated with intestinal dysmotility or pseudo-obstruction. These children often have a long history of gastroesophageal reflux, feeding intolerance, abdominal pain, constipation or diarrhea, and failure to thrive. Leigh disease, also known as subacute necrotizing encephalomyelopathy, usually presents in infancy with feeding or swallowing difficulties, failure to thrive, and vomiting.

Psychological causes of vomiting include anorexia nervosa, bulimia, hyperventilation, and severe anxiety. Accidental and nonaccidental poisoning with toxins such as lead, household cleaners, or medications such as acetaminophen, aspirin, or digitalis can stimulate emesis.

Munchausen syndrome by proxy should be suspected in cases of recurrent emesis that occurs only when a certain caregiver is present or when there are discrepancies in the case. Vomiting can be induced with drugs such as ipecac. Some medications and toxins can be found by urine, stool, or serum toxicology screens. Video surveillance is the easiest way to capture the perpetrator; however, this can be difficult to do for legal reasons, and many hospitals are not equipped for covert video surveillance. Apparent hematemesis can also be secondary to Munchausen syndrome by proxy. A transfusion with tagged red blood cells and a nuclear scan right after an episode of hematemesis can prove that the blood is not from the child.

Drug and alcohol abuse in children and teenagers can lead to emesis. Alcohol can cause emesis due to overdose as well as withdrawal. Withdrawal symptoms can begin anywhere from hours to a week after the cessation of alcohol ingestion. Patients can have tremor, anxiety, depression, nausea, vomiting, diaphoresis, tachycardia, hallucinations, seizures, and delirium tremens in severe cases. Abused opioids such as heroin, codeine, and hydromorphone can cause vomiting within hours of ingestion or during the withdrawal period, which can last for weeks. Other associated signs of withdrawal include tachycardia, irritability, pupillary dilation, diarrhea, and rhinorrhea.

Some recreational drugs can cause emesis during acute intoxication. Gamma hydroxybutyrate (GHB)—also known as Liquid Ecstasy, Liquid X, Georgia Home Boy, Grievous Bodily Harm, and Easy Lay—is a date-rape drug that causes sedation, amnesia, euphoria, and hallucinations. The more toxic effects include nausea, vomiting, loss of peripheral vision, respiratory depression, and coma. Ketamine can be ingested orally or nasally, smoked, or injected. It has dissociative effects and causes nystagmus, hallucinations, and vomiting.

Where is rebound tenderness a sign of appendicitis?

What is rebound tenderness and how is it assessed?

What is the clinical sign for rebound tenderness?

Is there rebound tenderness with appendicitis?