6.1 Nutrition and Hydration
Key Takeaways
- Basic Care and Comfort is 7-13% of the NCLEX-PN test plan; nutrition and hydration items recur heavily here.
- Confirm enteral tube placement before every feeding; gastric aspirate pH 1-5.5 supports placement but X-ray is the gold standard.
- Keep the head of bed elevated 30-45 degrees during feeding and at least 30-60 minutes after to prevent aspiration.
- Normal adult maintenance fluid need is about 30 mL/kg/day, roughly 2,000-2,500 mL for an average adult.
- Dehydration shows dry mucous membranes, poor turgor, urine specific gravity above 1.025, and tachycardia before hypotension.
Nutrition and Hydration
Nutrition and hydration questions appear throughout the Basic Care and Comfort category, which makes up 7-13% of the NCLEX-PN test plan. The exam is a computer-adaptive test (CAT) of 85-150 questions scored against the -0.18 logit passing standard upheld by NCSBN through March 31, 2029. Items in this section reward you for spotting the at-risk patient, choosing the safest intervention, and knowing the exact numbers that trigger reporting to the RN.
Nutritional Assessment
A complete assessment combines objective data, labs, and history. Memorize the lab thresholds the exam treats as red flags.
| Component | Key Indicators | Exam-Relevant Values |
|---|---|---|
| Anthropometrics | Weight, height, body mass index (BMI), unintentional loss | Loss >5% in 1 month or >10% in 6 months is significant |
| Visceral proteins | Albumin, prealbumin | Albumin <3.5 g/dL = malnutrition risk; prealbumin <15 mg/dL reflects recent intake |
| Hematology | Hemoglobin, lymphocytes | Hgb <12 (female)/<13.5 (male) suggests deficiency |
| History/function | Allergies, dysphagia, dentition, culture | Identifies aspiration and self-feeding risk |
BMI bands: underweight <18.5, normal 18.5-24.9, overweight 25-29.9, obese >=30.
Therapeutic Diets
Know indication and key features. The exam loves the renal vs cardiac distinction and the clear-to-full liquid progression after surgery.
| Diet | Indication | Key Feature |
|---|---|---|
| Clear liquid | Bowel prep, first post-op meal | Broth, gelatin, apple juice, tea; no milk or pulp |
| Full liquid | Transition step | Adds milk, cream soup, pudding |
| Mechanical soft / dysphagia | Chewing problems, stroke | Chopped, moist; thickened liquids per speech-language pathology |
| Low sodium (2 g) | Heart failure, hypertension | No added salt, avoid processed/canned foods |
| Renal | Chronic kidney disease | Limit sodium, potassium, phosphorus, and protein |
| Consistent carbohydrate | Diabetes mellitus | Even carb spread; avoid simple sugars |
| Low residue | Diverticulitis flare, Crohn flare | Limit fiber, seeds, raw produce |
| High protein/high calorie | Burns, wound healing | Eggs, meats, supplements |
Enteral Nutrition (Tube Feeding)
Use enteral feeding when the gut works but oral intake cannot meet needs. Nasogastric (NG) and nasoduodenal tubes are short-term (<4 weeks); a percutaneous endoscopic gastrostomy (PEG) or jejunostomy (J-tube) is long-term. Post-pyloric tubes (duodenal/jejunal) lower aspiration risk for high-risk patients.
Worked example: Your patient on continuous NG feeding has a 320 mL gastric residual volume (GRV). Many facilities hold the feeding and recheck when GRV is >250-500 mL; you keep the head of bed at 30-45 degrees, hold per protocol, and notify the RN rather than simply resuming. Always verify placement before each bolus: aspirate pH 1 to 5.5 supports gastric placement, but radiographic (X-ray) confirmation is the gold standard after initial insertion.
LPN/VN feeding checklist:
- Verify placement; check residual.
- Elevate head of bed 30-45 degrees during and >=30-60 minutes after.
- Flush with 30-60 mL water before/after feeding and between each medication.
- Give medications separately; never crush enteric-coated or extended-release tablets.
- Monitor for aspiration, diarrhea (often from formula or hyperosmolar meds), and refeeding electrolyte shifts.
Hydration and Fluid Balance
Adult maintenance fluid is about 30 mL/kg/day (roughly 2,000-2,500 mL). Compare dehydration to overload because the exam pairs them as distractors.
| State | Findings | Action |
|---|---|---|
| Dehydration | Dry mucosa, poor turgor, dark urine, specific gravity >1.025, tachycardia, then hypotension | Encourage fluids, monitor I&O, report low output, anticipate IV fluids |
| Fluid overload | Weight gain (1 kg ~ 1 L), crackles, jugular distention, dependent edema, dyspnea | Elevate head of bed, restrict fluids, monitor I&O, diuretics per order |
Trap to avoid: thirst and confusion are early dehydration cues in older adults, who lose the thirst response. A 1-kg overnight weight gain in a heart-failure patient signals fluid retention, not nutrition success.
Intake and Output Documentation
Accurate intake and output (I&O) records drive nearly every fluid-balance decision, and the exam expects you to know what counts. Intake includes oral fluids, ice chips counted as roughly half their volume, intravenous fluids, tube-feeding flushes, and irrigation that is not returned. Output includes urine, liquid stool, emesis, wound or surgical drainage, and measurable diaphoresis. Solid food is not charted as intake on an I&O record. When a patient is on a strict fluid restriction for heart failure or renal disease, the LPN/VN allots the daily total across shifts so the patient does not exhaust the allowance early in the day.
A reliable way to detect fluid shifts is the daily weight, taken at the same time each morning, after voiding, in the same clothing, on the same scale; a change of about 1 kilogram equals roughly 1 liter of fluid gained or lost.
Feeding the Patient at Risk for Aspiration
Many Basic Care items combine nutrition with safety. For a patient with dysphagia after a stroke, position fully upright at 90 degrees, offer thickened liquids at the prescribed consistency, place food on the unaffected side of the mouth, allow unhurried small bites, and keep suction available. Check for pocketed food in the cheeks before the next bite, and have the patient remain upright at least 30-60 minutes after the meal. Coughing, a wet or gurgly voice, drooling, or a delayed swallow are warning signs to stop feeding and notify the RN, who coordinates a speech-language pathology swallow evaluation.
Honoring religious and cultural food practices, such as kosher, halal, or vegetarian preferences, supports intake and dignity and is part of patient-centered care.
A patient receiving continuous nasogastric tube feeding has a gastric residual volume of 320 mL. Per facility policy feedings are held for residuals above 250 mL. What is the LPN/VN's best initial action?
Which laboratory value is the most sensitive indicator of the patient's recent nutritional intake over the past few days?
A patient with chronic kidney disease is started on a renal diet. Which foods should the LPN/VN teach the patient to limit?