LE2 SUMMARY 3

Slow visceral afferent C-fibers

Which nerve fiber type transmits slow, dull, poorly localized visceral pain from hollow organs?

Visceral pain

What type of pain is dull, diffuse, poorly localized, and felt along the embryologic origin midline due to smooth muscle stretch or ischemia?

Early appendicitis and biliary colic

What are classic clinical examples of visceral abdominal pain?

Fast A-delta somatic sensory fibers

Which nerve fiber type transmits sharp, intense, precisely localized somatic pain?

Somatic pain

What type of pain is sharp, intense, precisely localized, and caused by direct irritation or inflammation of the parietal peritoneum or abdominal wall?

Late appendicitis at McBurney point

What is a classic clinical example of somatic abdominal pain with localized peritonitis?

Referred pain

What term describes abdominal pain perceived in an extraintestinal cutaneous location distant from the site of origin due to shared spinal cord sensory convergence?

Lower lobe pneumonia presenting as epigastric pain

What is a classic clinical example of referred abdominal pain?

Abdominal wall pain

What type of superficial abdominal pain originates from skin, muscle, or fascia and remains palpable or worsens with rectus muscle contraction?

Positive Carnett sign

Which physical exam finding confirms an abdominal wall pain origin when pain increases or persists during rectus muscle contraction?

Rectus sheath hematoma and abdominal muscle strain

What are primary clinical examples of abdominal wall pain?

Epigastric area

Where is visceral pain from embryologic foregut organs localized?

Esophagus, stomach, duodenum, liver, gallbladder, and pancreas

Which organs are embryologically derived from the foregut?

Periumbilical area

Where is visceral pain from embryologic midgut organs localized?

Jejunum, ileum, cecum, appendix, ascending colon, and proximal 2/3 of transverse colon

Which organs are embryologically derived from the midgut?

Hypogastric or suprapubic area

Where is visceral pain from embryologic hindgut organs localized?

Distal 1/3 of transverse colon, descending colon, sigmoid colon, rectum, and pelvic organs

Which organs are embryologically derived from the hindgut?

Impaired linear growth or stunting

Which growth parameter abnormality serves as a key pediatric red flag for chronic organic GI pathology?

Impaired linear growth/stunting, involuntary weight loss, bilious vomiting, nocturnal pain awakening the child, localized non-periumbilical point tenderness, GI blood loss, and fever >39.4 C

What red flags distinguish pediatric organic abdominal pain from functional GI disorders?

Organic pathology such as IBD, malabsorption, or acute surgical abdomen

What is the clinical significance of pediatric alarm signs in abdominal pain evaluation?

Unexplained weight loss, persistent fever, progressive dysphagia, persistent vomiting, hematochezia or melena, nocturnal diarrhea, palpable mass, and severe pain out of proportion to exam

What alarm symptoms require urgent workup in adults with abdominal pain?

Malignancy, acute ischemia, bowel obstruction, or visceral perforation

What critical pathologies must be excluded when adult abdominal pain alarm symptoms are present?

Motor vehicle crashes (MVCs), falls, direct impacts, and compression or shearing forces

What are the primary etiologies of blunt abdominal trauma?

Gunshot wounds, stab wounds, impaled objects, and shrapnel

What are the primary etiologies of penetrating abdominal trauma?

Spleen

Which solid organ is most commonly injured in blunt abdominal trauma?

Liver

Which solid organ is most commonly injured in penetrating abdominal trauma due to its large size and anterior exposure?

Small intestine

Which hollow organ is most commonly injured in both blunt and penetrating abdominal trauma?

Initial physical exam can be benign or soft despite severe occult hemoperitoneum

What is the primary diagnostic challenge during initial physical examination in blunt abdominal trauma?

Missiles deflecting along unpredictable paths and determining fascial violation depth

What are the main diagnostic challenges in penetrating abdominal trauma?

FAST ultrasound

Which diagnostic tool is indicated for both hemodynamically UNSTABLE and STABLE blunt trauma patients?

Detection of free intraperitoneal fluid in 4 anatomical views

What is the primary diagnostic finding and strength of a FAST ultrasound exam?

Perihepatic (Morison pouch), Perisplenic, Pelvic (Pouch of Douglas), and Pericardial views

What are the four anatomical views examined during a FAST ultrasound?

Poor visualization in severe obesity or subcutaneous emphysema, and inability to grade solid organ injury

What are the main technical limitations of a FAST ultrasound?

CT scan with IV contrast

Which diagnostic modality is the gold standard for grading solid organ injuries and evaluating the retroperitoneum in hemodynamically STABLE trauma patients?

Hemodynamic instability

What is a strict absolute contraindication for performing an abdominal CT scan in a trauma patient?

Low sensitivity for detecting hollow viscus (bowel) perforation

What is a major diagnostic limitation of CT scanning in abdominal trauma?

Diagnostic Peritoneal Lavage (DPL)

Which invasive diagnostic procedure is indicated in hemodynamically UNSTABLE blunt trauma when FAST is equivocal or unavailable, or in brain-injured/intoxicated patients?

Prior abdominal surgeries, severe obesity, and pregnancy

What are relative contraindications for performing Diagnostic Peritoneal Lavage?

Local wound exploration

Which procedure is indicated in hemodynamically stable patients with anterior abdominal wall stab wounds without peritonitis?

Determining whether the anterior abdominal fascia has been violated

What is the primary objective of local wound exploration in stab wound evaluation?

Digital probing or exploration of stab wounds with fingers or forceps

Which examination maneuver is strictly prohibited when evaluating penetrating abdominal stab wounds?

Peritonitis with board-like rigidity, unexplained hemodynamic shock, evisceration of viscera, and penetrating GSW traversing peritoneal cavity

What are the four absolute indications for immediate exploratory laparotomy in trauma?

1. Control of life-threatening hemorrhage, 2) Control of GI contamination, and 3) Reestablishment of GI continuity

What are the three mandatory operative priorities during exploratory laparotomy for trauma?

Damage Control Surgery (DCS)

Which surgical strategy utilizes abbreviated laparotomy, temporary abdominal packing, and vacuum closure in patients with severe shock?

Acidosis, Coagulopathy, and Hypothermia

What three conditions comprise the Lethal Triad targeted for prevention by Damage Control Surgery?

24 to 48 hours after ICU resuscitation and physiological stabilization

When is a trauma patient returned to the operating room for definitive surgical repair following Damage Control Surgery?

Hepatomegaly, hepatic cyst, hemangioma, HCC, gallbladder hydrops, distended gallbladder (Courvoisier sign), choledochal cyst, and pancreatic head carcinoma

What mass etiologies are localized to the Right Upper Quadrant (RUQ)?

Splenomegaly, gastric tumor, GIST, pancreatic body/tail carcinoma, and splenic flexure colon cancer

What mass etiologies are localized to the Left Upper Quadrant (LUQ)?

Appendiceal abscess or mucocele, cecal carcinoma, Crohn ileitis mass, tubo-ovarian abscess, and ectopic pregnancy

What mass etiologies are localized to the Right Lower Quadrant (RLQ)?

Sigmoid colon carcinoma, diverticular abscess, impacted stool, ovarian cyst or tumor, and tubo-ovarian abscess

What mass etiologies are localized to the Left Lower Quadrant (LLQ)?

Gastric mucosal epithelium

What is the cell of origin / histology of gastric adenocarcinoma?

Stomach antrum and body

Where is gastric adenocarcinoma primarily located anatomically?

CEA and CA 19-9

Which tumor markers are elevated in gastric adenocarcinoma?

Dysphagia, early satiety, weight loss, and diagnostic EGD with biopsy

What are the key clinical features and diagnostic test for gastric adenocarcinoma?

Gastrectomy with D2 lymph node dissection

What is the primary surgical management for resectable gastric adenocarcinoma?

Interstitial cells of Cajal

What is the cell of origin for Gastrointestinal Stromal Tumors (GIST)?

Stomach (40-60%) and small bowel

What are the primary anatomical locations for GISTs?

c-KIT (CD 117) mutation

Which key gene mutation and protein marker characterize GISTs?

Smooth submucosal mass on CT/EGD that is hyperenhancing

What are the key diagnostic imaging features of GIST?

Surgical resection with or without Imatinib (tyrosine kinase inhibitor)

What is the primary medical and surgical management for GIST?

Hepatocytes

What is the cell of origin for Hepatocellular Carcinoma (HCC)?

Alpha-fetoprotein (AFP)

Which serum tumor marker is characteristically elevated in Hepatocellular Carcinoma?

Hypervascular arterial enhancement with portal venous washout on triphasic CT

What is the pathognomonic contrast enhancement pattern for HCC on triphasic CT?

Surgical resection, TACE/RFA, or Liver Transplantation based on Milan Criteria

What are the definitive treatment options for Hepatocellular Carcinoma?

Pancreatic ductal epithelium

What is the cell of origin for Pancreatic Ductal Adenocarcinoma?

Pancreatic head (60%), body, and tail

Where is pancreatic ductal adenocarcinoma most commonly located?

CA 19-9

Which serum tumor marker is used to monitor pancreatic ductal adenocarcinoma?

Painless jaundice, new-onset diabetes in patients >60 years old, and Courvoisier sign

What are the hallmark clinical presentation features of pancreatic head carcinoma?

Pancreaticoduodenectomy (Whipple procedure)

What is the primary surgical procedure performed for resectable pancreatic head cancer?

Fluid, Flatus, Feces, Fetus, Fat, and Fatal tumor

What are the '6 Fs' comprising the differential diagnosis of generalized abdominal enlargement?

Intraperitoneal fluid accumulation (ascites) from portal hypertension, cirrhosis, nephrotic syndrome, or carcinomatosis

What mechanism causes generalized abdominal enlargement from Fluid, and how is it evaluated?

Abdominal ultrasound and paracentesis calculating SAAG

What is the key diagnostic evaluation for ascites (Fluid)?

Gaseous intestinal distention from mechanical bowel obstruction or ileus

What causes abdominal enlargement from Flatus, and how is it evaluated?

Supine and upright abdominal radiographs

Which imaging study evaluates flatus and intestinal gas distention?

Severe constipation, megacolon, or fecal impaction evaluated by DRE and plain X-ray

What causes abdominal enlargement from Feces, and how is it evaluated?

Intrauterine pregnancy evaluated by routine urine hCG pregnancy test

What causes abdominal enlargement from Fetus, and how is it evaluated?

Routine urine pregnancy test (hCG)

Which test must be routinely performed in all females of childbearing age presenting with abdominal enlargement?

Large intra-abdominal or pelvic malignancy evaluated by contrast CT or MRI

What causes abdominal enlargement from a Fatal Tumor, and how is it evaluated?

Paraumbilical, strictly to the RIGHT of an intact umbilicus

Where is the anatomical defect located in gastroschisis?

Centered at the UMBILICUS

Where is the anatomical defect located in an omphalocele?

ABSENT protective sac; viscera directly exposed to amniotic fluid

What is the status of the protective sac in gastroschisis?

PRESENT 3-layer sac composed of amnion, peritoneum, and Wharton jelly

What covers the herniated viscera in an omphalocele?

Small bowel, stomach, and colon (rarely liver)

Which viscera characteristically herniate in gastroschisis?

Small bowel, LIVER (frequent), and spleen

Which viscera characteristically herniate in an omphalocele?

Matted, thickened, edematous, and inflamed due to amniotic fluid peritonitis

What is the condition of the herniated bowel at birth in gastroschisis?

Normal appearance beneath an intact protective sac

What is the condition of the herniated viscera at birth in an omphalocele?

Uncommon (<10%), primarily intestinal atresia

How common are associated congenital anomalies in gastroschisis?

COMMON (>50%), including cardiac, neural tube defects, and Beckwith-Wiedemann syndrome

How common are associated congenital anomalies in an omphalocele?

URGENT primary closure or spring-loaded silo reduction

What is the primary surgical management for gastroschisis?

Non-urgent; primary closure or topical escharification with silver sulfadiazine for giant defects

What is the surgical management for an omphalocele?

Intestinal bowel condition and complex status like atresia or necrosis

What is the primary determinant of prognosis in gastroschisis?

Severity of coexisting congenital and cardiac anomalies

What is the primary determinant of prognosis in an omphalocele?

Hernia of the umbilical cord

Which defect measures <3 cm at the cord base with an intact sac containing minor bowel loops, requiring careful cord clamping?

Umbilical hernia

Which abdominal wall defect involves a fascial ring covered by normal skin, closing spontaneously in 90% of children by age 2?

Persistent defect size >1.5 cm past age 5

When is surgical repair indicated for a pediatric umbilical hernia?

Pentalogy of Cantrell

Which cephalic fold defect comprises supraumbilical omphalocele, anterior diaphragmatic hernia, sternal cleft, pericardial defect, and intracardiac anomaly?

Bladder exstrophy

Which caudal fold defect presents as an open exposed mucosal bladder plate and epispadias?

Cloacal Exstrophy (OEIS Complex)

Which severe caudal defect comprises Omphalocele, Exstrophy of bladder/hindgut, Imperforate anus, and Spinal defects?

Physical luminal blockage with initially hyperactive colicky motility working against a barrier

What defines dynamic mechanical bowel obstruction?

Absent or paralyzed peristalsis without physical blockage, resulting in silent bowel sounds

What defines adynamic functional ileus?