43. ACUTE APPENDICITIS Flashcards
Definition
APPENDICITIS is defined as the inflammation of the vermiform appendix which ranges from a simple, congestive form to a more complicated transmural involvement eventually leading to perforation.
It is the most common abdominal surgical emergency with a lifetime risk of 8.6% in males and 6.9% in females
Anatomy
The vermiform appendix is located at the base of the cecum near the ileocecal valve where the taenia coli converge on the cecum which corresponds to McBurney’s point.
In contrast to an acquired diverticulum, the appendix is a true diverticulum which consists of all the layers of the colonic wall: mucosa, submuscosa, muscularis propria, and serosa
The appendicial orifice opens into the cecum
Its blood supply, the appendiceal artery, is a terminal branch of the ileocolic artery which traverses at the length of the mesoappendix and terminates at the tip of the organ.
The attachment of the base of the appendix to the cecum is constant. However, the tip may migrate to the retrocecal, subcecal, preileal, postileal and pelvic positions
These normal anatomic variations can complete the diagnosis as the site of pain and findings on clinical examination will reflect the anatomic position of the appendix.
Etiopathogenesis
The natural history of appendicitis is similar to that of other inflammatory processes, involving hollow visceral organs.
Initial inflammation of the appendiceal wall is followed by localized ischemia, perforation, and the development of a contained abscess or generalized peritonitis.
Appendiceal obstruction has been proposed as the primary cause of appendicitis.
Obstruction may be caused by fecaliths (hard fecal masses), calculi, foreign bodies, lymphoid hyperplasia, parasitic infections, or rarely, benign or malignant tumors.
Cause of LUMINAL OBSTRUCTION
usually depends upon the patient’s age.
In the young, lymphoid follicular hyperplasia due to infection as well as foreign objects like peanuts and seeds are the most common causes.
In older patients, luminal obstruction is mor elikely to be caused by fecaliths, calculi or tumors (carcinoid, adenocarcinoma, mucocele)
In endemic areas, parasites may be the cause in any age group
The pathogenesis of acute appendicitis occurs in 4 stages:
- stage of congestion
- Stage of suppuration
- Stage of gangrene
- stage of perforation
(1&2 - uncomplicated appendicitis)
(3&4 - complicated appendicitis)
State the Stage of Suppuration, Stage of Congestion, Suppuration, Gangrene, Perforation
STAGE OF CONGESTION
Normally, the appendix continuously produces secretions that easily escape toward the cecum.
However, in the presence of a proximal obstruction, these secretions ACCULUMATE –> causing distention of the appendix resulting to inc. intraluminal pressure
Eventually, this pressure will continue to increase until it overcomes the venous and lymphatic pressure, leading to stasis
In turn, this results to vascular engorgement and congestion
Because a greater pressure is required to compromise arterial blood flow, oxygen perfusion remains intact
Ischemia and necrosis do not ensue during this time
STAGE OF SUPPURATION
The congested appendix is a good medium for bacterial proliferation
Aerobic organisms predominate early in the course, while mixed infection is more common in late appendicitis
These bacteria will then incite an inflammatory reaction which soon involves the serosa and irritates the parietal peritoneum
The whole appendix now appears swollen and becomes coated with fibrinopurulent exudates
STAGE OF GANGRENE
With greater distention, intraluminal pressure eventually exceeds pressure in the arterioles
This impairs blood flow to the appendix leading to ischemia and necrosis. This is most prominent in the ANTIMESENTERIC BORDER border which receives the LEAST supply of blood presenting as ellipsoidal infarcts.
STAGE OF PERFORATION
Bacterial invasion; compounded by wall necrosis and infarction eventually leads to perforation, usually on the antimesenteric border.
CLINICAL PRESENTATION
In the classic presentation, the patient describes the onset of abdominal pain as the first symptom
Initially, the pain is PERIUMBILICAL in nature that is VAGUE, DULL and DIFFUSED which corresponds to the stimulation of the visceral afferent stretch fibers due to distention.
Eventually, as the inflammation progresses, there will be a MIGRATION of pain to the right lower quadrant w/c is somatic in nature and corresponds to the irritation of the parietal peritoneum (VOLKOVICH-KOCHER sign)
Although considered a classic symptom, MIGRATORY PAIN only occus in 50 to 60% of patients with appendicitis
Anorexia as well as nausea and vomiting usually follow the onset of pain
GI symptoms that develop before the onset of pain suggest a different etiology such as gastroenteritis
Fever generally occur later in the course of illness
Other assoc. GI symptoms include: indigestion, flatulence, diarrhea, bowel irregularity
Flank pain, dysuria or hematuria can occur given the typical proximity of the appendix to the urinary tract especially when the tip is located in the pelvis
Aggravating and alleviating factors may also help establish the diagnosis.
Worsening of pain with deep inspiration may be present if there is peritoneal inflammation.
Patients may also state that the trip to the hospital was painful, particularly when encountering bumps in the road
**Release of intraluminal obstruction with perforation often results in sudden improvement of pain Thus, we should consider perforation when patient’s pain has suddenly improved.
What are the things we should look out for in PE?
On PE, early signs of appendicitis are often SUBTLE and may be UNREVEALING in the very early stages
Low-grade fever reaching 38.3 may be present
Involvement of the overlying parietal peritoneum causes direct & rebound tenderness in the right lower quadrant = (+) BLUMBERG SIGN
Patients with RETROCECAL appendix may not exhibit marked localized tenderness in the RLQ since the appendix does not come in contact with the anterior parietal peritoneum **
RECTAL or PELVIC examination is more likely to elicit positive signs and should be differentiated from a TUBOOVARIAN ABSCESS or a RUPTURED OVARIAN CYST in females
Several findings on PE have also been described to facilitate diagnosisl, but these findings PRE-DATED DEFINITIVE IMAGING for appendicitis because of their low sensitivities and specificities
- PSOAS SIGN - manifested with RLQ pain with passive right hip extension. This sign is associated with RETROCECAL appendix wherein the inflamed appendix lies against the right psoas muscle
Sensitivity - 13 to 42%
Specificity - 79-97% - OBTURATOR SIGN - assoc. with a pelvic appendix and is based on the principle that the inflamed appendix may lie against the right obturator internus muscle. Thus, when the right hip is flexed as well as the knee followed by internal rotation of hip, RLQ pain is elicited
Sensitivity - 8%
Specificity - 94% - ROVSING’S SIGN - refers to pain in the RLQ with palpation of the left. While this maneuver stretches the entire peritoneal lining, it only causes pain in the location where the parietal peritoneum is irritated. Also, palpation of the left lower quadrant results to displacement of air and bowel contents towards the right increasing the pressure around the appendix.
Sensitivity - 22 to 68%
Specificity - 5 to 96% - DUNPHY’S SIGN - refers to increased pain in the RLQ and coughing
- AURE-ROZANOVA’S SIGN - increase pain on palpation in the right pefot triangle (omg ano to??? chz)
- MARKLE SIGN - pain in the RLQ by dropping from standing on the toes to the heels with a jarring landing
Diagnosis
Acute appendicitis is largely a CLINICAL DIAGNOSIS
It must be considered in any paient with atraumatic right-sided abdominal periumbilical or flank pain who has not previously undergone appendectomy
Althout rarely, patients may experience stump appendicitis brough about by inflammation of residual appendiceal tissue after appendectomy*
Scoring systems such as modified Alvarado scoring to aid in diagnosis. This scoring system includes 3 symptoms: 3 signs and 2 laboratory findings
***Maganda yung pagkadivide ni Dapoy ng MANTRELS
Symptoms:
M igration of pain
A norexia
N ause vomiting
Signs:
T enderness in the RLQ
R ebound tenderness
E levated temperature
Labs:
L eukocytosis
S hift of WBC count to the left
LEUKOCYTOSIS may be the earliest marker of inflammation but will not distinguish simple and perforated appendicitis.
Lahat sila 1 pt, ang mga 2 pts lang ay
Tenderness in the RLQ + Shift of WBC count
How to use alvarado scoring????
A score of less than 5 –> appendicitis UNLIKELY
5-6 –> POSIBLE
7-8 –> appendicitis LIKELY
9-10 –> HIGHLY LIKELY
However despite the presence of this scoring system, clinical judgement should not be replaced since it still has the HIGHEST IMPACT on patient outcome
Laboratory Exams
Aside from CBC, urinalysis may also be obtained to r/o ureteral stone and UTI
Ureteral stone - usually presents with gross or microscopic hematuria
UTI - presence of pyuria and bacteriuria
However, it is important to note that appendicitis may also present with hematuria and sterile pyuria
Pregnancy test in females of reproductive age must also be done to rule out ectopic pregnancy
Imaging
In the past, imaging techniques were not the norm and physicians relu on history and PE alone
The dictum was “when in doubt, take it out”. Thus, a negative appendectomy rate of 10 to 20% was allowed to minimize late diagnosis
This resulted in about 1 to 2 out of 10 patients having operation for a normal appendix
At present, there is now a PARADIGM shift and imaging is now accepted to further aid in diagnosis.
- GRADED COMPRESSION ULTRASOUND is the initial imagine modality of choice because it is non-inavsive, requires no contrast medium and emits no ionizing radiation
Typical findings are thickened, non-compressible appendix with >6mm diameter.**
Doppler may also show hyperemia**
The diagnostic accuracy of ultrasound is better at RULIN IN appendicitis than excluding it especially inc ases of perforation where specific imaging hallmarks may disappear.
Other limitations to accuracy include:
- operator skill
- retorcecal appendix
- excessive abdominal guarding
- bowel gas
- obesity
- In this case, ABDOMINOPELVIC CT SCAN is the next choice
CT Scan is EXTREMELY ACCURATE and has a sensitivity & specificity of >95%
The downside is that it frequently requires contrast administration and the concern for radiation exposure.
Current evidence reveals that 1 malignancy will result for every 555 patients who will undergo abdominopelvic CT scan
typical CT findings include a DILATED APPENDIX >6 mm in diameter with thickened wall, periappendiceal fat stranding and potential visualization of an appendicolith or an abscess
DIFFERENTIAL DIAGNOSIS
The m/c diagnosis made in the presence of a missed diagnosis is Gastroenteritis
UTI is also a common mistaken diagnosis
Other differentials include: Mesenteric Adenitis, Meckel’s diverticulitis, Renal Colic or Constipation
In females, this may include ectopic pregnancy, ovarian torsion or PID
Management
Patients with acute appendicitis typically require appendectomy
upon suspicion, patients should be placed on NPO to avoid operative delay
IV fluids must also be provided for maintenance and manage dehydration from diarrhea and vomiting, if present
Perioperative antibiotics must be initiated upon diagnosis which should cover both AEROBIC and ANAEROBIC ORGANISMS
Acceptable regimens include:
- CEFOXITIN 2g IV ANST
- AMPICILLIN-SULBACTAM 3 g IV ANST
- CIPROFLOXACIN 400 mg IV + METRONIDAZOLE 500 mg IV
Afterwhich, PROMPT APPENDECTOMY is perfromed
In uncomplicated appendicitis, this may be done through a McBurney or a Rocky-Davis Incision
Laparoscopic Appendectomy may also be done if available
In complicated appendicitis, especially if with perforation, Exploratory Laparotomy should be done for PERITONEAL WASHING
therapeutic antibiotics should also be given up to 7 to 1- days or until clinical resolution occurs
With the emergence of ERAS (enhanced recovery after surgery), it is now advocated that serving of food and drinks can be done on the day of the operation.
This will prevent negative protein balance to enhance and hasten patient recovery.
Patient is then discharged once stable and is advised to follow-up
Prognosis
Most people with appendicitis recover completely after surgery unless complications such as Peritonitis have occured.
Recovery time depends on age, condition and complications and is usually between 10 to 28 days.
Early postoperative complications may include: ileus, atelectasis, surgical site infections, wound dehiscence or an intraabdominal abscess
Late complications include postoperative adhesions or recurrence due to stump appendicitis
