Saturday, September 1, 2012

Acute Abdomen and Appendicitis

The term acute abdomen refers to signs and symptoms of abdominal pain and tenderness, a clinical presentation that often requires emergency surgical therapy.

Nonsurgical Causes of Acute Abdomen

Endocrine and metabolic causes
  • Uremia
  • Diabetic crisis
  • Addisonian crisis
  • Acute intermittent porphyria
  • Hereditary Mediterranean fever
Hematologic Causes
  • Sickle cell crisis
  • Acute leukemia
  • Other blood dyscrasias
Toxins and Drugs
  • Lead poisoning
  • Other heavy metal poisoning
  • Narcotic withdrawal
  • Black widow spider poisoning

Surgical Acute Abdominal Conditions

Hemorrhage
  • Solid organ trauma
  • Leaking or ruptured arterial aneurysm
  • Ruptured ectopic pregnancy
  • Bleeding gastrointestinal diverticulum
  • Arteriovenous malformation of gastrointestinal tract
  • Intestinal ulceration
  • Aortoduodenal fistula after aortic vascular graft
  • Hemorrhagic pancreatitis
  • Mallory-Weiss syndrome
  • Spontaneous rupture of spleen
Infection
  • Appendicitis
  • Cholecystitis
  • Meckel's diverticulitis
  • Hepatic abscess
  • Diverticular abscess
  • Psoas abscess
Perforation
  • Perforated gastrointestinal ulcer Perforated gastrointestinal cancer
  • Boerhaave's syndrome
  • Perforated diverticulum
Obstruction
  • Adhesion related small or large bowel obstruction
  • Sigmoid volvulus
  • Cecal volvulus
  • Incarcerated hernias
  • Inflammatory bowel disease
  • Gastrointestinal malignancy
  • Intussusception
Ischemia:
  • Buerger's disease
  • Mesenteric thrombosis or embolism
  • Ovarian torsion
  • Ischemic colitis
  • Testicular torsion
  • Strangulated hernias

Acute Appendicitis

Etiology/Pathophysiology
  • Obstruction of the lumen is the major cause. 
  • Obstruction may be due to inspissated stool (fecalith or appendicolith), lymphoid hyperplasia, vegetable matter or seeds, parasites, or a neoplasm
  • Obstruction of the appendiceal lumen contributes to bacterial overgrowth, and continued secretion of mucus leads to intraluminal distention and increased wall pressure.
  • Luminal distention produces the visceral pain sensation experienced by the patient as periumbilical pain.
  • Inflammation of the adjacent peritoneum gives rise to localized pain in the right lower quadrant.
  • perforation typically occurs after at least 48 hours from the onset of symptoms and is accompanied

Diagnosis/ Clinical features

History
  • Acute abdominal pain.
  • The typical presentation begins with periumbilical pain (due to activation of visceral afferent neurons) followed by anorexia and nausea.
  • The pain then localizes to the right lower quadrant as the inflammatory process progresses to involve the parietal peritoneum overlying the appendix.
  • This classic pattern of migratory pain is the most reliable symptom of acute appendicitis.
  • A bout of vomiting may occur, in contrast to the repeated bouts of vomiting that typically accompany viral gastroenteritis or small bowel obstruction.
  • Fever ensues, followed by the development of leukocytosis.
  • Occasional patients have urinary symptoms or microscopic hematuria, owing to inflammation of periappendiceal tissues adjacent to the ureter or bladder.
  • Most patients with appendicitis develop an adynamic ileus and absent bowel movements on the day of presentation, occasional patients may have diarrhea.
  • May present with small bowel obstruction related to contiguous regional inflammation.

Physical Examination

  • Pt. look ill and  lie still in bed.
  • Low-grade fever is common (∼38°C). 
  • Examination of the abdomen usually reveals diminished bowel sounds and focal tenderness with voluntary guarding.
  • The exact location of the tenderness is directly over the appendix, which is most commonly at McBurney's point (located one third of the distance along a line drawn from the anterior superior iliac spine to the umbilicus
  • Peritoneal irritation can be elicited on physical examination by the findings of voluntary and involuntary guarding, percussion, or rebound tenderness.
  • Pain in the right lower quadrant during palpation of the left lower quadrant (Rovsing's sign), pain on internal rotation of the hip (obturator sign, suggesting a pelvic appendix), and pain on extension of the right hip (iliopsoas sign, typical of a retrocecal appendix).
  • Rectal and pelvic examinations are most likely to be negative. However, if the appendix is located within the pelvis, tenderness on abdominal examination may be minimal, whereas anterior tenderness may be elicited during rectal examination as the pelvic peritoneum is manipulated. Pelvic examination with cervical motion may also produce tenderness in this setting.

iliopsoas sign


Obturator Sign


Rovsing’s sign


Laboratory Studies
  • The white blood cell count is elevated with more than 75% neutrophils.
  • Shift to left.

Radiography
Ultrasonography
  • appendix of 7 mm or more in anteroposterior diameter, a thick-walled, noncompressible luminal structure seen in cross section 
  • In more advanced cases, periappendiceal fluid or a mass may be found.

Computed tomography (CT)
  • Classic findings include a distended appendix greater than 7 mm in diameter and circumferential wall thickening, which may give the appearance of a halo or target .

Diagnostic Laparoscopy
  • Although most patients with appendicitis will be accurately diagnosed based on history, physical exam, laboratory studies, and if necessary, imaging techniques, there are a small number in whom the diagnosis remains unclear.
  • For these patients, diagnostic laparoscopy can provide both a direct examination of the appendix and a survey of the abdominal cavity for other possible causes of pain.
Shift to left


Treatment
  • Most patients with acute appendicitis are managed by prompt surgical removal of the appendix.
  • A brief period of resuscitation is usually sufficient to ensure the safe induction of general anesthesia.
  • Preoperative antibiotics cover aerobic and anaerobic colonic flora. For patients with nonperforated appendicitis, a single preoperative dose of antibiotics reduces postoperative wound infections and intra-abdominal abscess formation.
  • For patients with perforated or gangrenous appendicitis, we continue postoperative intravenous antibiotics until the patient is afebrile. 

Open appendectomy 
  • Transverse right lower quadrant incision (Davis-Rockey) or an oblique incision (McArthur-McBurney), Recently-Lanz incision, Rutherford Morison incision- ( Para and retrocaecal or fixed appendix)
  • For uncomplicated cases - transverse, muscle-splitting incision lateral to the rectus abdominis muscle over McBurney's point.
  • After the peritoneum is entered, the inflamed appendix is identified by its firm consistency and br the presence of taeniae coli.
  • The meso-appendix is divided between clamps and tied.
  • A heavy absorbable tie is placed around the base of the appendix clamped and divided.
  • An absorbable purse-string suture or Z stitch is placed into the cecal wall, and the appendiceal stump is inverted into a fold in the wall of the cecum. 

Division of  Mesoappendix

  • Ligation of the baseand division of the appendix,

Placement of purse-string suture or Z stitch, Inversion of the appendiceal stump.

Laparoscopic appendectomy
  •  A 10-mm port into the umbilicus, followed by a 5-mm port in the suprapubic midline region and a 5-mm port midway between the first 2 ports and to the left of the rectus abdominis muscle.
  • With the patient in Trendelenburg's position and rotated left-side down, then gently sweep the terminal ileum medially and follow the taeniae of the cecum caudad to locate the appendix, which is then elevated. The mesoappendix is divided.
  • Appendix is encircled with two heavy absorbable Endoloops cinched down at the base of the appendix and then a third Endoloop is placed about 1 cm distally and the appendix divided.

  • Location of port sites 
    for laparoscopic 
    Appendectomy




  • Division of the 
    mesoappendix 




  • Placement of an 
    Absorbable 
    Endoloop encircling 
    the base of the 
    appendix



  • Division of the 
    appendix between 
    Endoloops




Complication
  • Ruptured appendix 
  • Peritonitis and 
  • Abscess

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