NLE Gastrointestinal Nursing — Nutritional & Metabolic SupportCheat Sheet

Formulas

Common Values

Section Title

Nutritional Assessment & Anthropometrics

Important Facts

• BMI categories (WHO): underweight <18.5, normal 18.5–24.9, overweight 25–29.9, obese ≥30.
• Filipino/Asian cut-offs: underweight <18.5, normal 18.5–22.9, overweight ≥23, obese ≥27.5.
• Prealbumin is MORE SENSITIVE to acute nutritional changes; albumin is stable and reflects chronic status.
• Serum transferrin, total lymphocyte count (TLC <1,500/mm³ = depleted immunity), and electrolytes complete the picture.
• Anthropometrics + biochemical + clinical signs = complete nutritional assessment; never use one measure alone.
• Edema can mask true weight loss (patient looks heavier but is malnourished) — check for muscle wasting and skin turgor.
• Fever, stress, and wounds increase caloric needs; adjust nutritional support accordingly.

Key Definitions

Diagrams To Know

• Nutritional assessment pyramid (anthropometric → biochemical → clinical/dietary → functional status).
• BMI classification chart for standard and Asian populations side-by-side.

Common Values

Section Title

Obesity

Important Facts

• Obesity is MULTIFACTORIAL: genetic predisposition, behavioral habits (diet, sedentary), and environmental factors (food access, stress).
• Comorbidities: type 2 diabetes, hypertension, dyslipidemia, coronary artery disease (CAD), obstructive sleep apnea (OSA), fatty liver disease (NAFLD), osteoarthritis, and cancer (breast, colon, endometrial).
• Management LADDER: (1) diet + physical activity + behavior change FIRST, (2) pharmacotherapy if needed, (3) bariatric surgery for severe/refractory obesity.
• Target weight loss: ~0.5–1 kg/week is SUSTAINABLE; crash dieting fails long-term and harms metabolism.
• STIGMA REDUCES ENGAGEMENT: use weight-inclusive, non-judgmental language; avoid blame; emphasize health, not appearance.
• Nursing role: assess comorbidities, teach realistic goals, provide motivation and support, and screen for sleep apnea (critical in Philippine context where OSA is often missed).

Key Definitions

Diagrams To Know

• Obesity management algorithm (diet + activity → pharmacotherapy → surgery).
• Obesity-related comorbidity web (central obesity, insulin resistance, inflammation).

Common Values

Section Title

Malnutrition & Refeeding Syndrome

Important Facts

• REFEEDING SYNDROME PREVENTION is the #1 safety priority: START LOW, INCREASE SLOWLY; give THIAMINE before/with first feeding.
• In refeeding, carbohydrate (glucose) triggers INSULIN surge → shifts phosphate, potassium, and magnesium INTRACELLULARLY → SEVERE SERUM DEFICITS.
• Early signs of refeeding syndrome: weakness, cardiac arrhythmias, respiratory distress, confusion — often appear 24–48 hours after aggressive feeding starts.
• Electrolyte monitoring (phosphate, potassium, magnesium) is MANDATORY in first 3–5 days of feeding a malnourished patient.
• Manifestations of malnutrition: weight loss, muscle wasting, weakness/fatigue, poor wound healing, edema (hypoalbuminemia), impaired immunity (recurrent infections), anemia, and micronutrient deficiencies.
• Assessment triggers: BMI <18.5, unintentional weight loss >5% in 1 month or >10% in 6 months, prealbumin <20 mg/dL, albumin <3.5 g/dL.
• Treatment principle: 'Oral route first' — small frequent energy-dense meals + oral nutritional supplements (if tolerated) before enteral/parenteral support.
• Causes to investigate: inadequate intake (dysphagia, pain, depression), malabsorption (diarrhea, Crohn's, celiac), increased losses (vomiting, fistula), or increased needs (fever, wound, sepsis).

Key Definitions

Diagrams To Know

• Refeeding syndrome timeline: starvation → feeding started → 24–48 h → electrolyte crash → cardiac/respiratory crisis.
• Thiamine and B-vitamin depletion cascade in refeeding.

Reactions Or Equations

Common Values

Section Title

Enteral Nutrition (Tube Feeding)

Important Facts

• GOLDEN RULE: 'If the gut works, USE IT' — enteral feeding preserves gut integrity, is cheaper, and has fewer complications than TPN.
• TUBE PLACEMENT VERIFICATION (CRITICAL):
• • X-ray confirms initial placement (gold standard).
• • Before EVERY feed/medication: aspirate gastric contents, check pH ≤5.5 (gastric), observe appearance.
• • Auscultation ('whooshing' sound) is UNRELIABLE and should NOT be used alone.
• • Never assume placement without verification — aspiration into lungs is a serious complication.
• ASPIRATION PREVENTION (TOP PRIORITY):
• • Keep head of bed elevated 30–45° during feeding AND for 30–60 minutes AFTER.
• • Use continuous infusion (pump) rather than bolus if high aspiration risk.
• • Monitor for signs of aspiration: cough, fever, respiratory distress, new infiltrate on CXR.
• TUBE CARE & MAINTENANCE:
• • Flush with water BEFORE and AFTER every feed and medication (prevents clogging).
• • Give medications SEPARATELY, each one flushed independently.
• • Do NOT crush enteric-coated or sustained-release tablets (coat bypassed, absorption altered).
• • Administer liquid formulations of medications when possible.
• FORMULA DELIVERY METHODS:
• • Bolus/intermittent (4–6 times daily): closest to normal eating, used for gastric feeding, faster completion.
• • Continuous (pump over 18–24 hours): better tolerated, preferred for jejunal feeding and critically ill patients.
• • Start slow (20–30 mL/h), advance by 20–30 mL/h every 4–8 h as tolerated to reduce GI upset.
• FORMULA CONTAMINATION & STORAGE:
• • Use clean (non-sterile) technique for administration.
• • Limit hang time per protocol: typically 4–8 hours for open systems; refrigerate unused formula.
• • Discard formula at room temperature after 4 hours to prevent bacterial growth.
• COMPLICATIONS & MANAGEMENT:
• • Aspiration (MOST SERIOUS): elevate HOB, verify placement, consider continuous infusion or jejunal route.
• • Diarrhea: hyperosmolar formula, fast rate, antibiotics, C. diff risk — slow rate, add fiber, consider elemental formula.
• • Tube clogging: flush with warm water, use enzymatic declogger if needed.
• • Tube displacement: verify placement before each use; secure tube well.
• • Dumping-type symptoms: switch to lower osmolality formula, slower infusion rate, smaller frequent feeds.

Key Definitions

Diagrams To Know

• Tube feeding setup flowchart: assess → insert → verify → deliver → monitor → troubleshoot.
• Decision tree for choosing formula type (polymeric vs. elemental vs. disease-specific).
• Aspiration prevention checklist (HOB angle, tube verification, flush schedule, tube care).

Common Values

Section Title

Total Parenteral Nutrition (TPN)

Important Facts

• TPN INDICATION: GI tract CANNOT be used or inadequate (massive bowel resection, severe pancreatitis, prolonged ileus, intractable vomiting, high-output fistula).
• TPN MUST RUN THROUGH A CENTRAL LINE — the hyperosmolar dextrose (often 20–35%) would sclerose and damage a peripheral vein.
• SAFETY RULE #1 — NEVER STOP TPN ABRUPTLY:
• • Sudden cessation → rebound hypoglycemia (pancreas still secreting insulin).
• • ALWAYS TAPER the rate down gradually (e.g., reduce by 25% every 1–2 hours).
• • If the next bag is delayed/unavailable, hang 10% dextrose (D10W) at the SAME rate as TPN was running to prevent glucose crash.
• • NEVER substitute plain saline (0.9% NaCl) — this will cause hypoglycemia.
• SAFETY RULE #2 — USE AN INFUSION PUMP (not gravity) and STRICT ASEPTIC TECHNIQUE:
• • TPN is a perfect culture medium for bacteria and fungi → CRBSI is the top complication.
• • Meticulous hand hygiene, sterile dressing, and tubing changes per protocol (typically every 24 h for TPN tubing).
• SAFETY RULE #3 — MONITOR BLOOD GLUCOSE (every 4–6 hours initially, at least daily once stable):
• • Hyperglycemia is common early (stress response, dextrose load); use sliding-scale insulin as ordered.
• • Avoid 'catching up' if behind — do NOT speed up the infusion; this destabilizes glucose control and risks hyperglycemic crisis.
• • Keep the ORDERED RATE steady; use a pump with an alarm.
• SAFETY RULE #4 — DEDICATED ACCESS:
• • Do NOT use the TPN line for other IV medications, blood draws, or CVP readings unless a multi-lumen catheter with a DESIGNATED lumen is available.
• • Do NOT piggyback other meds into TPN tubing (precipitate risk, incompatibility).
• COMPLICATIONS & MONITORING:
• • CATHETER-RELATED:
• - Air embolism: during tubing changes — position patient LEFT side, head DOWN (Trendelenburg), have patient perform VALSALVA during connection; prevent by pinching catheter before disconnection.
• - Pneumothorax: during insertion (rare); watch for dyspnea, decreased breath sounds.
• - Thrombosis: swelling, pain, positional occlusion; may require thrombolytics or catheter removal.
• • METABOLIC:
• - Hyperglycemia (early, most common): insulin adjustment needed.
• - Hypoglycemia (if TPN stopped abruptly or rate cut): taper TPN, use D10W, monitor closely.
• - Refeeding syndrome (if patient was malnourished): gradual calorie increase, electrolyte monitoring, thiamine supplementation.
• - Hepatic dysfunction (long-term TPN >7–14 days): monitor ALT, AST, bilirubin; cholestasis risk; rotate amino acid source if needed.
• • INFECTIOUS:
• - CRBSI: fever, positive blood culture; suspect if fever develops on TPN; remove/replace catheter; broad-spectrum antibiotics.
• DAILY MONITORING CHECKLIST:
• • Weight (daily), strict I&O, blood glucose (every 4–6 h), electrolytes (daily), phosphate/magnesium (daily × 3–5 days, then 2–3×/week), liver function (2–3×/week), triglycerides (weekly; lipid emulsion risk).
• • Inspect catheter site for erythema, warmth, drainage, induration.
• • Assess for signs of infection (fever, chills, malaise) or metabolic derangement (confusion, weakness, cardiac dysrhythmia).
• TRANSITIONING OFF TPN:
• • As gut recovers, wean TPN GRADUALLY while advancing enteral/oral intake.
• • Taper TPN rate down (do not stop abruptly) as enteral intake increases.
• • Continue blood glucose monitoring during transition (insulin secretion lags behind falling glucose load).
• • Confirm patient is meeting ≥50–75% of needs orally/enterally before discontinuing TPN completely.

Key Definitions

Diagrams To Know

• TPN composition pyramid (dextrose + amino acids + lipids + electrolytes + vitamins + trace elements).
• TPN troubleshooting flowchart: hyperglycemia → hypo → infection → metabolic derangement.
• Air embolism emergency response (LEFT lateral, Trendelenburg, Valsalva, O2, call team).

Reactions Or Equations

Common Values

Section Title

Bariatric Surgery & Post-Operative Nursing

Important Facts

• BARIATRIC SURGERY INDICATIONS:
• • BMI ≥40 kg/m² (or ≥35 kg/m² with obesity-related comorbidities: diabetes, hypertension, sleep apnea, CAD).
• • Failed conservative management (diet + exercise) for ≥6 months.
• • Psychological readiness; commitment to lifelong dietary adherence and supplementation.
• POST-OP NURSING PRIORITIES:
• • ANASTOMOTIC LEAK (EARLY RECOGNITION — LIFE-THREATENING):
• - CLASSIC TRIAD: fever + tachycardia (>120) + acute abdominal pain.
• - Also watch for: restlessness, increased respiratory rate, elevated WBC with left shift.
• - Can occur Day 1–5 post-op; suspect even with subtle signs.
• - Management: NPO, broad-spectrum antibiotics, emergency imaging (CT with oral contrast), surgical re-exploration likely.
• • AIRWAY/RESPIRATORY:
• - Many bariatric patients have sleep apnea (undiagnosed or known).
• - Post-op risk: opioid use depresses respiratory drive in apneic patient → hypoxia.
• - Monitor O2 saturation closely; consider ICU stay if severe OSA; use analgesia cautiously.
• • DEEP VEIN THROMBOSIS (DVT) & VENOUS THROMBOEMBOLISM (VTE) PROPHYLAXIS:
• - Bariatric patients at high VTE risk (obesity, surgery, immobility).
• - Enoxaparin/heparin + early ambulation + compression stockings.
• • NUTRITION & FEEDING PROGRESSION:
• - Post-op diet is staged: clear liquids → full liquids → soft foods → regular (high-protein, small-volume meals).
• - Strict portion control (pouch capacity ~30 mL initially, gradually stretches to ~150 mL).
• - NO straws (increase swallowing of air); sip slowly; separate food and fluids.
• • PAIN MANAGEMENT:
• - Avoid NSAIDs (increase leak risk early post-op).
• - Acetaminophen and opioids (short-term); taper opioids to avoid dependency and constipation.
• DUMPING SYNDROME PREVENTION:
• • Eat SMALL frequent meals (4–6 meals/day, 1–1.5 cups per meal).
• • Avoid SIMPLE SUGARS and high-osmolarity foods (sweets, sugary drinks, fruit juices).
• • Eat PROTEIN and COMPLEX CARBS (higher satiety, slower gastric emptying).
• • DRINK FLUIDS BETWEEN MEALS, NOT WITH MEALS (dilutes food, increases osmolarity, speeds emptying).
• • Lie down 30 minutes after eating (slows gastric emptying, reduces dumping).
• • Adequate fiber (prevents both constipation and diarrhea).
• LIFELONG NUTRITIONAL DEFICIENCIES (HIGH-YIELD):
• • Bariatric surgery causes malabsorption due to reduced gastric capacity and bypassed bowel.
• • MANDATORY lifelong supplementation (adherence critical for health):
• - IRON (especially women of child-bearing age): microcytic anemia, fatigue, pallor; check ferritin annually.
• - VITAMIN B12 (loss of intrinsic factor + reduced stomach acid + bypassed ileum): macrocytic anemia, neurologic symptoms (paresthesia, ataxia, dementia if severe); injections or sublingual forms often needed; check serum B12 and methylmalonic acid/homocysteine.
• - FOLATE: macrocytic anemia; often depleted alongside B12.
• - CALCIUM + VITAMIN D: reduced absorption (D aids Ca absorption); risk of osteomalacia, tetany, bone loss; monitor alkaline phosphatase, 25-OH vitamin D.
• - THIAMINE (B1): Wernicke encephalopathy risk if depleted; ensure supplementation.
• - Zinc, copper, selenium (trace elements).
• • Annual monitoring: CBC, vitamin B12, folate, iron studies (ferritin, TIBC), alkaline phosphatase, calcium, vitamin D, albumin.
• POST-BARIATRIC NUTRITIONAL TEACHING:
• • Chew thoroughly (prevent obstruction, aid digestion).
• • Eat slowly (allow satiety signals to reach brain); ~20–30 min per meal.
• • Protein FIRST (every meal must contain protein to prevent muscle loss and maintain satiety).
• • Take multivitamin + minerals DAILY (bariatric-specific formulation if possible).
• • Attend support groups and follow-up appointments (improve long-term outcomes).

Key Definitions

Diagrams To Know

• Roux-en-Y bypass anatomy: gastric pouch + limb bypass diagram.
• Anastomotic leak emergency response (fever + tachy + pain → imaging → surgery).
• Dumping syndrome timeline and prevention strategy flowchart.

Common Values

Section Title

Micronutrient Deficiencies — Recognition & Clinical Picture

Important Facts

• IRON DEFICIENCY: microcytic, hypochromic anemia; fatigue, weakness, dyspnea; pallor, tachycardia; koilonychia (spoon nails); elevated TIBC, low ferritin/serum iron.
• B12 DEFICIENCY: macrocytic anemia; fatigue, weakness, glossitis (sore tongue); NEUROLOGIC: paresthesia (feet/hands), ataxia, 'stocking-glove' distribution; can progress to dementia if untreated; elevated homocysteine, methylmalonic acid; low serum B12.
• FOLATE DEFICIENCY: macrocytic anemia (indistinguishable from B12 deficiency on CBC alone — must check B12 and folate levels); often co-occurs with B12 deficiency post-bariatric.
• VITAMIN D & CALCIUM: bone pain, muscle cramps, tetany (severe hypo-Ca), osteomalacia (soft bones, fractures); elevated alkaline phosphatase; low 25-OH vitamin D (<20 ng/mL); low serum calcium.
• THIAMINE: EMERGENCY deficiency (Wernicke encephalopathy): acute confusion, ophthalmoplegia (can't move eyes), ataxia (can't walk) — requires URGENT thiamine replacement IV/IM (can be irreversible if delayed); chronic deficiency (wet beriberi): heart failure, peripheral neuropathy.
• VITAMIN C: poor wound healing, bleeding/perifollicular hemorrhages, perifollicular hemorrhages, anemia (affects iron absorption); scurvy is rare in developed countries but seen in severe malnutrition.
• VITAMIN A: night blindness (first sign), dry skin (xerosis), increased respiratory/GI infections (immune impairment).
• ZINC: impaired wound healing, altered taste (hypogeusia), dermatitis (especially perioral, around eyes).
• Clinical recognition is KEY on NLE: must be able to match symptoms to deficiency (e.g., 'patient with post-bypass surgery, neurologic paresthesia and ataxia' → think B12 deficiency).

Key Definitions

Diagrams To Know

• Micronutrient deficiency symptom reference card (iron → B12 → folate → vitamin D → thiamine → vitamin C → vitamin A — each with hallmark signs).
• Lab values quick reference (low ferritin, low B12, low folate, low 25-OH vitamin D, elevated alkaline phosphatase, etc.).

Item

BMI = weight (kg) ÷ height (m²); Use LOWER Asian/Filipino cut-offs: overweight ≥23, obese ≥27.5 kg/m² (NOT WHO standard ≥25 and ≥30)

Rank

1

Item

REFEEDING SYNDROME is a deadly complication when a starved patient is fed too aggressively → HYPOphosphatemia, HYPOkalemia, HYPOmagnesemia + thiamine depletion. PREVENTION: START LOW and SLOW; GIVE THIAMINE before/with feeding; MONITOR & REPLACE electrolytes closely × 5 days.

Rank

2

Item

GOLDEN RULE: 'If the gut works, USE IT' — enteral feeding is ALWAYS preferred over TPN (preserves gut, cheaper, fewer complications).

Rank

3

Item

TPN MUST RUN THROUGH A CENTRAL VENOUS LINE (not peripheral) because the dextrose is hyperosmolar and would sclerose a peripheral vein. Use pump + strict aseptic technique (CRBSI is the top complication).

Rank

4

Item

NEVER STOP TPN ABRUPTLY → REBOUND HYPOGLYCEMIA (pancreas still secreting insulin). ALWAYS TAPER and if the next bag is delayed, hang 10% dextrose (D10W) at the SAME rate. NEVER substitute plain saline.

Rank

5

Item

Tube feeding PLACEMENT VERIFICATION: X-ray confirms initial placement; before EVERY feed/med: aspirate & check pH ≤5.5 (gastric). Auscultation is UNRELIABLE — do NOT use alone. Always verify before feeding to prevent aspiration.

Rank

6

Item

ASPIRATION PREVENTION (enteral): Keep HOB elevated 30–45° DURING and FOR 30–60 MINUTES AFTER feeding. This is the #1 nursing action to prevent the most serious enteral complication.

Rank

7

Item

AIR EMBOLISM during TPN tubing change: Position patient LEFT LATERAL, Trendelenburg (head DOWN), have patient VALSALVA during connection. Prevention: never allow air into central line.

Rank

8

Item

DUMPING SYNDROME (post-bariatric): Small frequent meals, LOW simple carbs, HIGH protein/fat, DRINK FLUIDS BETWEEN (NOT WITH) meals, lie down 30 min after eating. Explain this to EVERY post-bariatric patient.

Rank

9

Item

Post-bariatric LIFELONG DEFICIENCIES: Mandatory supplementation of B12, iron, folate, calcium, vitamin D, thiamine. Annual monitoring labs. Patient MUST understand this is lifelong, not temporary.

Rank

10

Tip

On exam, recognize REFEEDING SYNDROME presentation: malnourished patient + aggressive feeding → HYPOphosphatemia + weakness + arrhythmias. The answer is always 'start feeding slowly, give thiamine, replace electrolytes' — this is tested EVERY year on NLE.

Tip

TPN questions almost always test the safety rule: 'Do NOT stop TPN abruptly.' If a scenario shows TPN being discontinued, the correct answer is 'taper and use D10W' — NOT to stop and observe. This is a high-yield trap.

Tip

When enteral feeding complications are presented (diarrhea, aspiration, tube clogging), the answers usually revolve around: verify placement first, slow the rate, flush the tube, elevate HOB, and assess tolerance. Master these steps.

Tip

Bariatric surgery questions test post-op complications: recognize ANASTOMOTIC LEAK as the most serious (fever + tachycardia + acute abdominal pain = EMERGENCY). Also know dumping syndrome management (small meals, avoid sugars, fluids between meals, lie down after eating) — this is heavily tested.

Tip

Micronutrient deficiency matching is a favorite NLE item: night blindness (vitamin A), paresthesia + ataxia (B12), poor wound healing (vitamin C/zinc), bone pain (vitamin D/calcium). Practice matching symptoms to deficiencies — do mock questions until automatic.

Rows

Columns

• Feature
• Marasmus
• Kwashiorkor
• Mixed Malnutrition

Table Title

Marasmus vs Kwashiorkor vs Mixed Malnutrition

Rows

Columns

• Aspect
• Enteral Feeding
• Total Parenteral Nutrition (TPN)

Table Title

Enteral vs Parenteral Nutrition — Quick Comparison

Rows

Columns

• Formula Type
• Protein Source
• Carbohydrate
• Fat
• Osmolality
• When to Use

Table Title

Formula Types — Enteral Nutrition

Rows

Columns

• Surgery Type
• Mechanism
• Pouch Size
• Weight Loss
• Malabsorption Risk
• Dumping Syndrome Risk

Table Title

Bariatric Surgery Types — Restrictions & Malabsorption

Rows

Columns

• Category
• WHO Standard
• Asian/Filipino Cut-Off
• Clinical Significance

Table Title

BMI Classification — Standard vs Asian Cut-Offs

Rows

Columns

• Complication
• Cause
• Signs/Symptoms
• Management

Table Title

TPN Complications — Recognition & Management