[08.11] SUR - Surgically Compromised Gut V2.pdf

6.5 to 9.7 Liters

What is the total combined daily volume of external intake and endogenous GI secretions entering the normal digestive tract?

2 Liters

How much fluid is typically ingested daily through oral food and drink, assuming eight 250 mL glasses?

0.5 to 1 Liter

What is the total daily volume of saliva secreted by the salivary glands into the GI tract?

2 to 3 Liters

What is the normal total daily volume of gastric juice secreted by the stomach?

0.5 to 0.8 Liter

What is the normal total daily volume of pancreatic juice secreted into the small intestine?

0.5 to 0.9 Liter

What is the normal total daily volume of bile produced and secreted by the liver?

500 mL

What is the total daily volume of mucus secreted throughout the GI tract from mouth to anus?

1 to 2 Liters

What volume of fluid undergoes passive secretion proximally and absorption distally in the jejunum?

2 to 5 Liters

What volume of fluid is actively absorbed daily in the ileum alongside Vitamin B12 and bile salts?

400 mL

What is the normal volume of fluid excreted daily in the feces under healthy physiological conditions?

From the mouth to the anus

Where are goblet cells located along the gastrointestinal tract?

5 to 6 meters

What is the normal anatomical length of the human small intestine?

Duodenum

Which segment of the small intestine is not considered part of the main absorptive surface of the GI tract?

Jejunum and Ileum

In which two specific anatomical segments of the small intestine does the vast majority of fluid absorption occur?

Colon

Which organ possesses a large absorptive capacity for reabsorbing remaining water, electrolytes, and short-chain fatty acids, but cannot replace small bowel functions?

Proximal and middle small intestine

In which regions of the small intestine are dietary fats, sugars, peptides, amino acids, folate, iron, and calcium primarily absorbed?

Distal small intestine (terminal ileum)

Which specific intestinal region is exclusively responsible for the active absorption of bile salts and Vitamin B12?

Colon

Where in the lower GI tract are medium-chain triglycerides, amino acids, water, and electrolytes absorbed?

Hyperphagia

What compensatory physiological mechanism involves eating significantly increased amounts of food to offset intestinal malabsorption?

Acute on top of chronic dehydration leading to acute kidney injury

What severe renal complication develops rapidly in short bowel patients who lose unabsorbed fluids and electrolytes?

End-jejunostomy

What surgical procedure brings the remaining proximal jejunum out through the abdominal wall as a stoma when the distal bowel is removed or bypassed?

Superior Mesenteric Artery (SMA)

Which end-artery supplies the capillary bed of the small intestine, leading to extensive bowel infarction if occluded by a thrombus or embolus?

High risk of anastomotic disruption and leakage

Why do surgeons avoid performing immediate bowel re-anastomosis in patients with borderline, unhealthy, or gangrenous bowel?

Short Bowel Syndrome (SBS)

What clinical state of malabsorption results from insufficient intestinal surface area for fluid, energy, and nutrient absorption following surgery or disease?

Jejunal atresia

What congenital developmental anomaly presents at birth with a lack of GI continuity, requiring emergency newborn surgery?

Superior mesenteric artery thrombosis, volvulus (mesenteric twisting), and strangulation

What are the main acute vascular causes of extensive small bowel necrosis leading to SBS?

Crohn's disease

Which chronic inflammatory bowel disease requires repeated intestinal resections for perforation, bleeding, or obstruction, leading to acquired SBS?

Villi atrophy and decreased villi numbers

What structural mucosal change causes non-surgical short bowel syndrome in autoimmune or radiation-induced enteritis?

Radiation enteritis

Which oncologic therapy complication induces long-term intestinal vasculitis, inflammation, and late stricture formation in the bowel?

100 cm or less

What is the classic anatomical definition threshold of remaining intact small bowel length for Short Bowel Syndrome in adults?

Less than 115 cm

Below what length of remaining small intestine is an adult prone to severe dehydration, malnutrition, and lifelong TPN dependence in the ABSENCE of a functioning colon?

Less than 60 cm

Below what length of remaining small intestine is an adult prone to severe dehydration, malnutrition, and lifelong TPN dependence in the PRESENCE of a functioning colon?

Gastric antrum (distal stomach)

Where is intrinsic factor, essential for Vitamin B12 absorption, produced and secreted?

Terminal ileum

Where is the Intrinsic Factor-Vitamin B12 complex reabsorbed in the gastrointestinal tract?

Megaloblastic (macrocytic) anemia

What hematologic disorder develops as a result of Vitamin B12 deficiency following terminal ileal resection or gastrectomy?

Bile salts are cathartic and irritate the colonic mucosa

Why does unabsorbed bile salt spilling into the colon induce severe watery diarrhea and green-stained stools?

Choleretic enteropathy

What term describes diarrhea and colonic mucosal irritation caused by bile salt malabsorption following moderate (<100 cm) ileal resection?

Steatorrhea

What clinical condition occurs when terminal ileal resection exceeds 100 cm, depleting circulating bile salts below micelle-forming concentrations?

Gastric acid hypersecretion (hypergastrinemia)

What gastric functional alteration occurs within the first 1 to 2 years following extensive small bowel resection?

Fat entering the terminal ileum

What specific nutrient stimulus triggers the physiological "ileal brake" mechanism under normal conditions?

Peptide YY (PYY) and Glucagon-like Peptide 2 (GLP-2)

Which two gut peptides released from the terminal ileum and cecum mediate the ileal and colonic braking mechanisms?

Slows gastric emptying and decelerates small intestinal transit

What is the physiological effect of the ileal brake on gastrointestinal motility?

Faster gastric emptying and accelerated small intestinal transit

What happens to GI motility when the ileal and colonic braking mechanisms are lost post-resection?

Ghrelin

Which hormone produced by the stomach acts as an orexigenic signal to stimulate appetite?

Semaglutide and Tirzepatide

Which GLP-1 receptor agonist medications mimic natural gut braking signals to slow gastric emptying and induce early satiety?

Intestinal adaptation

What physiological process increases the absorptive capacity of remaining small bowel over 24 to 48 hours up to 2 years post-resection?

Epithelial cellular hyperplasia, increased villi length and density, and increased bowel diameter

What structural changes characterize intestinal adaptation in remaining small bowel?

Jejunum-Ileum group

Which anatomical group of SBS patients (resected jejunum, intact ileum and colon) rarely requires parenteral nutrition and can maintain a normal diet?

Jejunum-Colon group

Which SBS group (resected ileum, intact jejunum and colon) develops gradual undernutrition but undergoes functional intestinal adaptation over time?

Jejunostomy group

Which SBS group (absent ileum and colon, end-jejunostomy) experiences severe fluid/electrolyte losses and exhibits NO functional intestinal adaptation?

Parenteral nutrition (TPN)

What specialized nutritional therapy is required for Jejunum-Colon patients with <70 cm small bowel or Jejunostomy patients with <75 cm small bowel?

Fatty acids bind calcium and magnesium, leaving free oxalate to be absorbed in the colon

Why do patients with fat malabsorption and an intact colon develop calcium oxalate renal stones?

High carbohydrate, normal fat, low oxalate diet

What dietary composition is recommended for SBS patients with an intact colon to prevent nephrolithiasis and optimize energy?

Semi-elemental or elemental diets

What simplified enteral formulas containing pre-digested peptides and simple carbohydrates facilitate absorption in a shortened jejunum?

Loperamide

Which anti-motility agent, administered at doses up to 18 to 36 mg daily (30 minutes before meals), slows intestinal peristalsis in SBS?

Codeine and Diphenoxylate

Which opioid anti-motility medications slow gastrointestinal transit but have restricted availability in the Philippines due to abuse potential?

Cholestyramine and Colestipol

Which bile salt sequestering agents reduce choleretic diarrhea and oxalate absorption when <100 cm terminal ileum is resected?

D-lactic acidosis

What metabolic condition causes acute neurological confusion in SBS patients when unabsorbed carbohydrates are fermented by colonic bacteria?

Hyperammonemia from inadequate citrulline manufacture

What metabolic disturbance in SBS causes confusion due to impaired urea cycle intermediates, treated with oral arginine?

100 mmol/L Sodium and 15 mmol/L Potassium

What is the approximate electrolyte composition of stomal fluid exiting an end-jejunostomy?

The low-sodium fluid causes the jejunum to excrete salt into the lumen, increasing fluid loss

Why does drinking low-sodium or hypotonic fluids (like plain water or sports drinks) worsen dehydration in a jejunostomy patient?

Oral Rehydration Solution (ORS) containing ~100 mmol/L Sodium

What specific oral solution must be consumed by jejunostomy patients to ensure net salt and water absorption?

Secondary hyperaldosteronism driven by severe sodium depletion

What endocrine mechanism causes urinary and GI potassium wasting, leading to hypokalemia in short jejunum patients?

Hypomagnesemia

What electrolyte deficiency impairs renal potassium channel function and must be corrected before refractory hypokalemia will resolve?

Octreotide

Which somatostatin analogue acts as a potent anti-secretory agent ("magic bullet") to dramatically decrease stomal and GI secretions, though limited by high cost?

Remaining small bowel length, presence of ileocecal valve, intact functioning colon, disease-free remnant bowel, and degree of intestinal adaptation

What are the five main factors determining whether an SBS patient can successfully resume an oral diet?

Restrict oral water and hypotonic fluids; give oral glucose-saline drinks (100 mmol/L Na)

What fluid management strategy is implemented when remaining small bowel is <200 cm?

Parenteral saline infusion

What intravenous fluid support is required when remaining small bowel is <100 cm without a functioning colon?

Lifelong parenteral nutrition (TPN) and intravenous saline

What specialized support is required when remaining small bowel length is <50 cm?

Proton pump inhibitors (PPIs)

Which anti-ulcer medication class treats post-resection gastric acid hypersecretion during the first 1 to 2 years?

Cholylsarcosine

Which synthetic conjugated bile acid derivative treats severe fat malabsorption and steatorrhea?

25 to 35 kcal/kg/day

What is the baseline daily energy requirement for a healthy adult before accounting for SBS hyperphagia?

1.0 to 1.5 g/kg/day

What is the baseline daily protein requirement for a healthy individual?

Medium-Chain Triglycerides (MCTs)

What type of dietary fat is directly absorbed without requiring bile salt micelle formation, making it ideal for SBS patients?

10,000 to 50,000 units daily

What is the recommended daily oral supplementation dosage of Vitamin A in Short Bowel Syndrome?

1,000 µg subcutaneously monthly

What is the recommended route, dose, and frequency of Vitamin B12 replacement for patients with terminal ileal resections?

200 mg daily

What is the daily recommended oral dosage of Vitamin C in Short Bowel Syndrome?

1,600 units daily

What is the daily recommended oral dosage of Vitamin D in Short Bowel Syndrome?

30 IU daily

What is the daily recommended oral dosage of Vitamin E in Short Bowel Syndrome?

10 mg weekly

What is the recommended oral dosage and schedule for Vitamin K in Short Bowel Syndrome?

1,000 to 1,500 mg daily

What is the daily recommended elemental Calcium intake in Short Bowel Syndrome?

60 to 150 µg daily

What is the daily recommended oral dose of Selenium in SBS?

220 to 440 mg daily

What is the daily recommended oral dosage of Zinc (as sulfate or gluconate) in SBS?

Octreotide

Which antidiarrheal medication is referred to as the "magic bullet" for reducing high-output GI secretions?

Jejunum and Ileum

In which part of the GI tract does the majority of fluid absorption take place?

Succus entericus leaking from surgical incision or drain site

What key clinical finding indicates an anastomotic breakdown or bowel perforation following abdominal surgery?

Frozen abdomen

What pathological state occurs when severe intra-abdominal inflammation causes dense fibrous adhesions binding all bowel loops and mesentery together?

Enteroatmospheric fistula (EAF)

What severe complication occurs when an enteric fistula opens directly into an open abdominal wound without surrounding skin coverage?

Central Line-Associated Bloodstream Infection (CLABSI) or CRBSI

What life-threatening systemic infection complication arises from prolonged central venous catheter use for TPN?

Type I Intestinal Failure

Which category of intestinal failure is acute, short-term, self-limiting, and commonly caused by post-operative ileus, trauma, or acute sepsis?

Type II Intestinal Failure

Which category of intestinal failure is acute, prolonged, and occurs in metabolically unstable patients requiring weeks to months of IV support (e.g. temporary SBS or complex fistulae)?

Type III Intestinal Failure

Which category of intestinal failure is chronic and irreversible, occurring in metabolically stable patients requiring months to years of home IV support (e.g. chronic SBS or permanent EAF)?

70%

What is the mortality rate associated with an enteroatmospheric fistula in an open abdomen?

Absence of a true fistula tract and lack of coverage by vascularized tissue

Why is spontaneous closure impossible in an enteroatmospheric fistula compared to an enterocutaneous fistula?

High-output fistula

How is an enteric fistula classified when output originates proximally (near stomach/jejunum), causing severe fluid and electrolyte losses?

Low-output fistula

How is an enteric fistula classified when output originates distally (near colon), making fluid management easier?

Early recognition and aggressive management of sepsis

What is the single most urgent initial treatment objective in managing intestinal failure?

Source control

What surgical and drainage principle involves cleaning, repairing, or diverting intestinal contents away from the peritoneal cavity?

30 to 35 kcal/kg/day

What is the calculated daily energy requirement for hypermetabolic, catabolic patients with intestinal failure and open wounds?

1.5 to 2.5 g/kg/day

What is the recommended daily protein intake for patients with intestinal failure to promote wound healing and tissue building?