Exam 4 Study Guide

Two compartments, and three spaces outside the cells

Water is the body's most important nutrient. It does six jobs: it carries nutrients, wastes, hormones and blood cells; supports cell metabolism; dissolves electrolytes and nonelectrolytes; keeps body temperature normal; aids digestion and elimination; and lubricates tissue.

Two barriers divide it. The cell membrane separates the fluid inside cells from everything outside them, and the capillary wall separates the blood from the fluid around the cells. That gives two compartments, and the outer one has three spaces.

Age, sex and fat

Fat holds little water and muscle holds a lot, so body water varies with build and age. Three groups differ from the healthy adult's 50–60%:

In and out: about 2,600 mL a day

Water comes from three sources: drinks (the largest), food, and metabolism (water released as food is oxidized). In a healthy adult, intake and output both average about 2,600 mL a day, and urine output roughly tracks what is drunk. Output leaves by two kinds of loss, and one tempting third category is not a loss at all.

Sources sort sweat differently: Taylor counts evaporation and perspiration through the skin as insensible and visible sweat as sensible; ATI lists sweat as sensible. Breath and unseen skin evaporation are insensible in every source.

Judge the balance over 2–3 days, not one shift: a single day can run short or long and mean nothing. Fever raises insensible loss: a temperature of 101–103 °F (38.3–39.4 °C) adds at least 500 mL a day, and anything above 103 °F adds at least 1,000 mL.

The deck and Taylor split the 2,600 differently between drinks and food, and among skin, lungs and gut. Only the totals and urine's 1,500 mL agree, so those are the figures to know.

Four ways across a membrane

Body fluid is solutes (electrolytes, and nonelectrolytes such as glucose and urea) dissolved in a solvent, water. Four processes move them. The exam worksheet matches each process to one phrase, shown in the last column.

Push, pull and albumin: why fluid leaves a capillary

Osmotic pressure is the pull that dissolved particles exert on water. When the particles are plasma proteins, chiefly albumin, which are too large to leave the vessel, it is called oncotic (colloid osmotic) pressure. Two pressures oppose each other across every capillary wall.

When the push outruns the pull, or the wall itself leaks, fluid collects in the tissues as edema. The four ways that happens, and third spacing, are in Part 2 (Third spacing and edema); the pitting scale was taught in NUR 120 (Exams 2 and 4).

The same pressures run in reverse when blood volume falls. Fluid moves from the interstitium into the vessels; the interstitium is left concentrated and pulls water out of the cells. The body protects the circulating volume first, at the expense of the tissues and then the cells. That is why the early signs of a deficit show in the mouth, the skin and the pulse before the blood pressure falls (Part 2).

Holding the balance: thirst, three hormones, nine organs

Thirst is the main control on intake. It is run from the hypothalamus and triggered by cells losing water (concentrated ECF draws water out of them) and by falling blood volume. It weakens with age, so older adults are offered fluid at regular intervals rather than when they ask. Output is controlled by three hormones, all acting on the kidney.

Taylor does not name ANP, so don't expect an item keyed on it.

The exam worksheet pairs nine organs with one phrase each, as below.

Tonicity: what a solution does to a cell

Osmolality is the concentration of particles in a fluid. Tonicity compares a solution's particles with plasma's, and so predicts which way water will move by osmosis. Water always moves toward more particles. There are three tonicities:

Not one of these: isotonic exercise (Exam 2) is constant muscle tension with movement. It shares the word with an isotonic solution, not the meaning. Which IV bags fall in each group, and the D5W exception, are in Part 5.

Taylor writes osmolality and puts plasma at about 280 mOsm/L; the deck writes osmolarity. The serum osmolality lab value is in Part 2.

Five volume words, sorted by what was lost or gained top-weighted topic

Fluid problems come in two kinds: volume (too little or too much) and distribution (a normal amount in the wrong place). There are five words to keep apart: two deficits, two excesses and one shift. Within each pair, the deciding feature is whether sodium moved in step with the water.

Taylor files both deficits under “fluid volume deficit” and does not define dehydration separately. The deck and ATI treat dehydration and hypovolemia as two disorders, so a stem that pairs “dehydration” with a high sodium means the water-only loss.

Third spacing and edema: fluid in the wrong place

Edema is excess ECF in the interstitium. Fluid leaves a capillary when the hydrostatic push out beats the oncotic pull back in (Part 1, Push, pull and albumin). There are four ways the balance tips.

Third spacing. Fluid is trapped in the pleural, peritoneal (ascites) or pericardial space, the joints, the bowel or the interstitium. It has not left the body, but the circulation cannot use it, so the patient shows a deficit: tachycardia, falling BP, low urine output. The causes are low albumin, too much volume (excess IV fluid, kidney failure), high capillary pressure (heart failure), leaky capillaries (trauma, burns) and low serum sodium. The weight does not fall and the loss cannot be measured on the I&O.

Where edema shows. In the lower legs of a patient who walks and the presacral area of a patient in bed. It is not visible until 5–10 lb of fluid has been retained, which is why the scale catches it first. Edema is localized (a thrombophlebitis) or generalized (heart failure, cirrhosis, nephrotic syndrome). The pitting scale is NUR 120 material (Exams 2 and 4); measuring the limb with a tape at the same marked spot each day is more exact than grading it.

The wet/dry stick figure, head to toe

The assignment is a blank figure: label the signs of hypervolemia (wet) on one side and hypovolemia (dry) on the other. Fill your own in before reading the key; the act of placing each sign on a body part is what makes it stick.

Measuring fluid status: what each measure is worth

Assessment rests on four parameters: the history and physical, intake and output, daily weights, and labs. Look hardest at the four risk groups: acute or chronic illness (diabetes, heart failure, renal failure); abnormal losses (vomiting, diarrhea, draining wounds, fistulas); burns, trauma and surgery; and therapies that shift fluid (diuretics, steroids, IV therapy, parenteral nutrition).

Daily weight, the most accurate measure

1 kg ≈ 1 L ≈ 2.2 lb (NUR 120 Exam 4). Weigh at the same time, on the same scale, in similar clothing, best in the morning after voiding and before breakfast. Weight is more accurate than I&O, and in an infant it is the most reliable indicator of fluid balance. A rapid loss of 5% in an adult or 10% in an infant signals FVD; a gain over 5% signals FVE. The lb↔kg arithmetic is in the Dosage Calculation guide.

Intake and output: what counts

Tell the patient, the family and every caregiver that everything is measured. Normal turnover is about 2,600 mL in and out a day (Part 1, In and out), and the balance is judged over 2–3 days, not one shift. Intake well below output signals a risk of FVD; well above, a risk of FVE. Refresher (Dosage Calculation guide): report the balance with its sign, e.g. −350 mL; assistive personnel may measure, but the nurse interprets.

Urine output and specific gravity are fluid-status measures too; the report threshold, the SG range and how to read SG against the volume are in Part 6 (Normal versus abnormal urine).

Bedside technique, and what fools you

NUR 120 taught the back of the hand as the turgor site. For fluid status, use the sternum, inner thigh or forehead instead: hand skin loses elasticity with age, so it tents in older adults who are not dry. In an older adult, confirm with the tongue, the mucosa and an orthostatic BP.

Labs

Taylor uses about 280 mOsm as the reference point for plasma.

Three patients, three shapes

The unit's three video cases are the shapes scenario items come in: an excess with electrolytes piling up, an excess from a failing pump, and a deficit in a child.

Problems, outcomes and interventions

There are three NANDA labels: Excess fluid volume, Deficient fluid volume and Risk for deficient fluid volume. Items may instead use the three newer problem labels below, each with its own cues.

Exam 3's red rule still applies: no medical diagnosis and no symptom after R/T. The three expected outcomes: intake and output balanced at about 2,500 mL a day, averaged over 3 days (a round goal near the ~2,600 mL turnover); urine SG within 1.010–1.025; and the patient practises self-care that keeps the balance (for example, losing 4 lb a month after cutting sodium).

Nursing care, dry versus wet

One table for both problems, in the order you work: assess, act, teach, delegate, evaluate. Most rows are mirror images. The how-to for fluids, diet and diuretics is in the table after it.

Third spacing. Nurse it as a deficit in the vessels: heart rate, BP, LOC, hourly output and fluids as ordered. Weight and I&O miss the loss (above), so they cannot show improvement either. When the cause settles and the fluid returns to the vessels, the risk flips to overload, so keep listening to the lungs.

Teach the patient to report four things: a rapid weight gain or loss; swollen fingers, feet or ankles, or puffy eyelids; scanty or very heavy urine; and muscle weakness or a change in skin sensation. Warn against casual use of enemas, laxatives, antacids and over-the-counter “water pills”.

Evaluate with five questions: is intake about equal to output; do the weight and the I&O agree; are the abnormal losses responding; are the signs resolving without new ones caused by the therapy; can the patient manage self-care?

Seven numbers, seven jobs

An electrolyte breaks apart in water into charged particles, ions. Cations are positive (Na⁺, K⁺, Ca²⁺, Mg²⁺, H⁺); anions are negative (Cl⁻, HCO₃⁻, phosphate). In health total cations equal total anions, and both are counted in milliequivalents (mEq), a unit of chemical activity. A nonelectrolyte stays intact in solution; glucose and urea are the two examples to know.

Items match each electrolyte to its range and to its job, so learn the range and the job together. Two of the seven are in mg/dL (calcium and phosphorus); the other five are in mEq/L.

Taylor gives calcium as 8.6–10.5 mg/dL (ionized 4.5–5.6), and its imbalance table uses Mg above 2.1 and Cl below 98 or above 108. ATI uses Na 136–145, Ca 9–10.5 and Mg 1.3–2.1. Use the course numbers.

Inside or outside. Four live mainly in the ECF: sodium, chloride, calcium and bicarbonate. Three live mainly in the ICF: potassium, phosphate and magnesium. That is why a sodium problem shows up as water moving into or out of cells (Part 1, Tonicity).

Where each comes from, how it is lost, and what controls it

Most of the seven arrive in food and leave through the kidneys, the gut or the skin. The food column is what you name when you teach.

The imbalance grid: four patterns before the details top-weighted topic

The four patterns.

1. Potassium, high or low, threatens the heart. Both directions cause muscle weakness, paresthesias and dysrhythmias. The history tells them apart: renal failure or a KCl infusion points high; vomiting, suction or a loop diuretic points low.
2. Sodium, high or low, threatens the brain. Low sodium lets water into cells, which swell; high sodium pulls water out, and they shrink.
3. Low calcium and low magnesium are twitchy: tingling, cramps, tetany, hyperactive reflexes, seizures.
4. High calcium and high magnesium are sluggish: lethargy, weak or absent reflexes; high magnesium also slows the breathing.

Potassium and sodium: the heart and the brain top-weighted topic

Potassium

Why potassium is the dangerous one. Its range is narrow, only 1.5 mEq/L from floor to ceiling, so a small move is a big one. It carries the heart's impulses. The kidneys cannot hold on to it when intake stops, yet they are its main exit, so when they fail it piles up. That is why IV potassium is never given as a bolus: a bolus raises the serum level suddenly and causes a fatal dysrhythmia. Never IV push (NUR 110 Exam 1). How it is diluted, run and capped: Part 5, IV potassium.

Sodium

Calcium, magnesium and phosphorus: the nerve-and-muscle minerals top-weighted topic

Calcium

Magnesium

Phosphorus, and chloride in one line

Chloride. It follows sodium. Low chloride (vomiting, gastric suction, diuretics, metabolic alkalosis) is twitchy like low calcium; high chloride travels with metabolic acidosis and high sodium. Care follows the partner problem: the sodium row, or the acid–base imbalance (Part 4).

Reading a patient: which electrolyte, and which one first

Read the deciding sign, then check the history for the cause.

When two values are abnormal, rank by the function each value threatens, not by how many points it sits outside its range. The order is the ABCDE framework from Exam 3, applied to electrolytes. Four tiers, in order:

1. Airway and breathing. Low calcium with laryngeal spasm; high magnesium with a falling RR or lost reflexes; low phosphorus or a potassium below 2.5 with weak respiratory effort.
2. Circulation: heart rhythm. Any potassium out of range with weakness or rhythm changes, or with a cause that will keep pushing it (renal failure, a KCl infusion running). Potassium is the commonest electrolyte answer to “who first”, because a breathing problem is rarer.
3. Disability: the brain. Sodium with confusion or seizures, in either direction, or below 120; tetany or seizures from low calcium or magnesium.
4. The rest. An abnormal value in an alert, stable patient whose cause is already being treated.

What the nurse does, across every imbalance top-weighted topic

Each grid row holds its own treatment; the care that repeats across rows lives here once, in nursing-process order.

The care-plan line. For a patient not yet out of range, the NANDA label is Risk for electrolyte imbalance: risk factors, and no “as evidenced by”. Example: Risk for electrolyte imbalance related to gastric fluid loss through NG suction and loop-diuretic therapy. Measurable outcome: serum K stays 3.5–5.0 mEq/L and Mg 1.3–2.3 mEq/L on daily labs, with a regular apical pulse and no leg cramps, through discharge.

The links: drugs, acid–base, the kidneys and immobility

Most electrolyte items hide the cause in the medication list or the history. Eight links to know:

Acids, bases and the 20 : 1 ratio

An acid releases hydrogen ions (H⁺); a base traps them. The more free H⁺, the lower the pH. On the 1–14 scale 7 is neutral, but blood lives in a narrow band: 7.35–7.45, slightly alkaline. Below 7.35 is acidosis, above 7.45 is alkalosis, and below 6.80 or above 7.80 life cannot continue.

Two chemicals carry the whole story. Carbonic acid is the acid the lungs control, by blowing CO₂ off or holding it in, which is why CO₂ acts as an acid. Bicarbonate (HCO₃⁻) is the base, and the kidneys control it. What sets the pH is not the amount of either but their ratio: about 20 parts bicarbonate to 1 part carbonic acid. Every imbalance in this part is that ratio tipping one way; every rescue is the other side tipping to match.

Three defences, fastest first

Three systems guard the ratio. Learn them in order of speed, because that is how items ask for them.

Across the lifespan. Newborns cannot acidify their urine well. In older adults the lungs and kidneys both work less efficiently, especially with lung disease, so both ends of life have less room for error.

Reading a gas: the refresher

The normals and method are unchanged from NUR 120 Exam 3 (and NUR 110 Exam 3 for the respiratory pair).

Say it as a sentence: “The pH is acid. The CO₂ is acid. They match — so it is respiratory acidosis.” ATI's ROME is the same rule seen through direction: Respiratory Opposite (pH and PaCO₂ move opposite ways), Metabolic Equal (pH and HCO₃ move the same way). If both numbers match an acid pH, both are causing it: a combined acidosis, the one picture the four steps cannot name alone.

Drawing one (NUR 110 Exam 3): Allen test before a radial stick; the O₂ setting on the requisition; the specimen on ice and to the lab promptly; pressure 5–10 minutes, longer on anticoagulants.

The four imbalances

Each name has two halves: which system started it (respiratory means carbonic acid is off; metabolic means bicarbonate is off) and which way the pH went. The respiratory pair is a refresher, one row each; the metabolic pair is new, and the next section gives its causes in depth.

Acidosis depresses the brain; alkalosis excites it (NUR 120 Exam 3): drowsy and confused on one side, tingling and twitchy on the other. The tingling and twitching of alkalosis look like low calcium: with a normal calcium after vomiting or suction, think metabolic alkalosis (Part 3, Calcium, magnesium and phosphorus).

Read five gases. Cover the right-hand columns, run the four steps, then check.

What the nurse does

Evaluate four things in every row: the repeat gas moving toward pH 7.35–7.45; mental status back to baseline; breathing at a normal rate and depth (in metabolic acidosis, easing as the acid clears); and K⁺ within 3.5–5.0.

Metabolic causes: what was lost, what was gained

Every metabolic cause comes down to one of four moves: acid lost, acid gained, base lost or base gained. Name the move and the imbalance follows.

The GI rule from NUR 120 Exam 3 still settles most items: vomiting loses acid, so alkalosis; diarrhea loses bicarbonate, so acidosis. Sort by what leaves, not by the route.

Potassium rides along

Hydrogen and potassium trade places across the cell membrane. In acidosis, H⁺ moves into cells and K⁺ moves out, so serum K⁺ rises; that is why hyperkalemia so often comes with metabolic acidosis. In alkalosis the trade reverses and serum K⁺ falls. Low potassium also feeds metabolic alkalosis, so the two sustain each other. Insulin pushes K⁺ into cells too. Treat every acid–base patient as a potassium patient, and so as a heart patient (Part 3, Potassium and sodium).

Compensation: the rescue

When one system tips the ratio, the other system pushes back. NUR 120's rule still holds: only the number that matches the pH names the imbalance; a number reading the other way is the rescue, not the disease. The lungs rescue metabolic problems within minutes. The kidneys rescue respiratory problems over hours to days; in respiratory alkalosis they start after about 6 hours.

Why culprit and rescue move together on paper. High CO₂ means acid but high HCO₃⁻ means base, so a rescue pushes the second number the same direction as the first: both up, or both down. A COPD patient who has retained CO₂ for years also carries a high bicarbonate. That is the kidneys' rescue, not a second disease.

How far this exam goes. The program limits ABG work to non-compensatory acid–base balance, so expect the partner number to be normal in most items. The course deck's ABG patterns, though, print the rescue in: respiratory acidosis with HCO₃⁻ “normal or slightly elevated”, respiratory alkalosis with HCO₃⁻ <22, metabolic acidosis with PaCO₂ <35, metabolic alkalosis with PaCO₂ >45. Meet one of these and step 4 still names it; the extra number is the rescue.

Solutions by tonicity: what each bag does to the cells top-weighted topic

Tonicity compares a fluid's particle concentration with plasma's, and water moves toward the side with more particles (Part 1, Tonicity). So the label on the bag tells you which way water will move once it is running: into the cells, out of them, or nowhere.

Apply the deck's hypertonic question (Part 1, Tonicity) to the bedside: the water a hypertonic bag pulls out of the cells lands in the circulation, so the patient to watch is the one whose heart or kidneys cannot handle more volume. Listen for crackles.

Venous access: choosing the site and the device

Gauge. 20–24 g for most adults; 22–26 g for neonates, children, older adults and anyone with poor veins; blood 20–24 g, or 18–20 g for a rapid transfusion. Children: hand, forearm, or the foot if not yet walking; scalp veins only as a last resort. Older adults' thin veins infiltrate easily, so limit the tourniquet (or use a BP cuff), lower the insertion angle, and watch the rate closely: with less heart and kidney reserve, overload comes sooner, from a bag or a transfusion.

Technique, the testable points. A tourniquet 3–4 inches above the site, with the radial pulse still present. Skin prep with chlorhexidine in alcohol, left to air-dry: no wiping, fanning or blowing, and no touching the site afterwards. Confirm a blood return and a flush without resistance. Transparent dressing, labelled with date, time, site, and catheter type and size. Two attempts per nurse at most, then escalate. Starting an IV is surgical asepsis (Exam 1) and is never delegated to assistive personnel.

The six devices

PICC veins: the deck lists basilic, median cubital, brachial and cephalic; Taylor lists basilic, brachial (preferred) and cephalic, above the antecubital fossa. Don't key the median cubital on its own.

A central device is considered when therapy will run longer than about 15 days, or the fluid would injure a small vein. Choose the least invasive device, with the smallest diameter and fewest lumens that will do the job.

Running an infusion: priming, labelling, piggybacks, pumps and rates

Hanging a bag uses the same rights and checks as a medication: compare it with the MAR, check the expiry date, scan it, and inspect the fluid for clarity and particles. Priming, in five steps:

1. Close the roller clamp and spike the bag without touching the port.
2. Fill the drip chamber at least halfway.
3. Prime the whole tubing until every bubble is gone, then clamp.
4. Label the bag (name, solution, additives, date, time) and add a time tape; label the tubing with the date of its next change.
5. Recheck the site and rate 30 minutes after starting, then check the infusion at least hourly.

Pumps. They are standard care, and a smart pump does not take away your responsibility for programming it. The alarms mean air, occlusion, low volume or rising pressure; rising pressure can be an infiltrating site (trap at the end of this section). Keep a time tape on the bag even on a pump, and run children's infusions on a pump, not by gravity. Too fast causes fluid overload; too slow leaves a deficit.

How often things are changed

ATI and older test banks give a routine PIVC change every 72–96 h; Taylor replaces it when clinically indicated.

Discontinuing a PIVC, in six steps. (1) Clamp the tubing. (2) Remove the dressing while stabilising the hub. (3) Withdraw the catheter without bending it, and don't press on it as it comes out. (4) Then press dry sterile gauze on the site until the bleeding stops; an alcohol pad stings and does not stop bleeding. (5) Check that the tip is intact; if it is not, put a tourniquet high on the limb and notify at once. (6) Occlusive dressing, then document.

When something goes wrong at the site, five rules. Resistance on flushing: never force it; restart elsewhere. Catheter partly out: never re-advance it. Tubing disconnected: discard the set. Artery hit, or tingling on insertion: remove, apply pressure, notify. Hematoma forming: remove and use a new site.

Caring for a running IV: the nurse's five jobs

IV complications: read the site, then act top-weighted topic

Local complications are more common; systemic ones (overload, air embolism, sepsis) are more dangerous. Pain and swelling go with every local complication, so they decide nothing. Temperature and colour decide. The table below has eight complications.

IV potassium: the speed limit

Blood: compatibility, giving it, and reactions

Typing identifies the blood type; crossmatching tests the donor's blood against the recipient's. A red cell carries antigens, and the plasma carries antibodies against the antigens the person lacks.

Rh is a second, separate match. The D antigen present means Rh-positive. An Rh-negative patient receives Rh-negative blood: Rh-positive blood makes them form antibodies, and a later transfusion then destroys red cells. An Rh-negative donor can give to an Rh-positive patient.

Components, five. Packed red cells raise the hemoglobin without much volume; fresh frozen plasma gives clotting factors and volume; platelets treat a low count; albumin treats low albumin and hypovolemic shock; cryoprecipitate treats low fibrinogen and hemophilia. Whole blood is rare.

The route, and how voiding works

Urine passes through four structures: kidney, ureter, bladder, urethra. How the kidneys decide how much to make is Part 1, Holding the balance.

Voiding (micturition) is a spinal reflex that the brain learns to control after infancy. Stretch receptors fire as the bladder fills, and the urge begins at about 150–250 mL. To void, the detrusor contracts, the internal sphincter, perineal muscles and external sphincter relax, and the abdominal wall tightens slightly. Voluntary control covers three things only: starting, holding back and interrupting. Normal voiding is painless. Embarrassment can stop it altogether, which matters when you need a specimen. A bladder cut off from the brain by injury or disease still empties by reflex: an autonomic bladder (Part 7, Incontinence).

The female urethra is short and close to the vagina and rectum, which is why women get more UTIs (Part 7). The male urethra is long and curved and passes through the prostate, which can obstruct it.

ATI says the adult bladder comfortably holds 300–400 mL and signals at 250–400 mL. Use 150–250 mL for the point at which the urge begins.

Normal voiding and normal output

Healthy adults void roughly every 3–4 hours while awake and usually not during sleep. The first morning void is the most concentrated, which is why some tests ask for it. How often someone voids depends on how much urine is being made, so a change from the person's usual pattern, not the pattern itself, is what suggests illness. Habitually holding urine for 8–12 waking hours breeds UTIs.

Taylor gives typical adult output as about 1,500 mL a day, roughly 40–80 mL/h. Those describe average output; 30 mL/h is the report threshold.

What changes voiding

Eight diseases linked to kidney problems: congenital urinary tract abnormalities, polycystic kidney disease, UTI, urinary stones, hypertension, diabetes mellitus, gout and connective tissue disorders. The last four are diseases of other systems, so they are the ones most often missed on a select-all item. Ask about all eight in the history (next section).

Drugs that change the amount or emptying. Retention: anticholinergics, antihistamines and OTC cold remedies, antidepressants, calcium-channel blockers, opioids and epidural analgesia. More urine: diuretics. Blunted reflex or awareness: analgesics, sedatives and tranquillisers. Nephrotoxic: NSAIDs such as aspirin and ibuprofen, and gentamicin. Watch I&O and the renal labs, because nephrotoxicity does not announce itself as frequency, incontinence or nocturia.

Nocturia, a refresher (NUR 120 Exam 4): alone in an older adult it is ageing; with ankle edema and orthopnea it points to heart failure.

Assessing urinary function: ask, inspect, palpate, measure

A focused urinary assessment runs in four steps, in this order: ask, inspect, palpate or percuss, measure. Judge every finding against the patient's own usual pattern.

1. Ask: the history, under five headings

Use the patient's own words for urinating; for a child, record the child's word for needing to go, and for an infant count wet diapers. Review the medication list against the drugs above. When a problem comes up, explore how long, how bad, what brings it on and what they already do about it.

2–3. Inspect, then palpate and percuss: five sites

4. Measure: three situations

Who does what. An AP may measure, empty and record. The nurse makes sure the AP knows the procedure, validates the accuracy, and does the assessment and the interpreting (Part 2, Measuring fluid status).

Normal versus abnormal urine

Taylor gives specific gravity as 1.005–1.030 in Ch 41 and 1.015–1.025 in Ch 38, and urine pH as 4.5–8 (usually 5–6). A value well outside every range, such as 1.035 or 1.002, means the same thing under all of them.

The reagent strip (dipstick) screens at the bedside. Hold the thick end, dip so every pad is soaked, tap off the excess, lay it on its side and read it against the colour chart at the time the manufacturer specifies. An abnormal strip needs lab confirmation.

The eight terms, as one family

Also: glycosuria, proteinuria, pyuria (pus) and bacteriuria (bacteria without symptoms, not a UTI: Part 7).

Some sources set anuria at less than 100 mL in 24 h. Taylor and the Ch 38 deck both use less than 50 mL.

Collecting urine specimens

Every specimen is labelled in front of the patient (two identifiers, date and time) and bagged. Urine changes as it stands, so it reaches the lab promptly (ideally within 2 hours) or is refrigerated.

A culture and sensitivity (C&S) names the organism and the antibiotics that work on it, in 24–48 hours; a UA shows bacteria but not which ones.

From the port of an indwelling catheter, in six steps:

1. Gather a syringe sized to the test, an antiseptic swab, a sterile container, clean gloves and a clamp.
2. If the tubing is empty, clamp it below the port for no more than 30 minutes so fresh urine collects.
3. Scrub the port with the swab and let it dry.
4. Attach the syringe and aspirate slowly.
5. Remove the syringe and release the clamp.
6. Transfer to the sterile container, label at the bedside, bag and send.

The Ch 38 deck now confirms the port, as Taylor does. The only outlier is the insertion checklist, which takes a specimen at insertion from the brand-new drainage bag. For any exam item, answer with the port.

The bladder scanner and the post-void residual

A portable ultrasound bladder scanner estimates the volume in the bladder. It is non-invasive, painless and carries almost no infection risk, so it is preferred over catheterising just to find out, and it cuts catheter use and CAUTI. The post-void residual (PVR) is what is left straight after voiding.

Scanning, in seven steps:

1. Patient supine and draped; a right-handed nurse stands on the right.
2. Turn it on, choose SCAN and select the patient's biological sex.
3. Clean the scanner head and palpate the symphysis pubis.
4. Put a generous amount of ultrasound gel, never lubricant, midline 1–1.5 in above the symphysis.
5. Point the direction icon toward the head and aim slightly down toward the coccyx.
6. Centre the bladder on the crosshairs, rescanning until it is centred, then read the volume.
7. Clean up; document why you scanned, the volume and the response.

A PVR under 50 mL is adequate emptying; over 100 mL, the bladder is not emptying properly. Measuring the residual does not help the patient void; what comes next is retention care (Part 7). Ascites makes the reading inaccurate.

The same scan tells retention (a full bladder) from low production (a nearly empty one): Part 7, Retention.

Other diagnostic tests, briefly

Incontinence: sort it by where the failure is top-weighted topic

Three rules hold for every type. Behavioural measures come first. An indwelling catheter is the last choice, because of infection. Absorbent products are not a treatment: they protect skin and clothing, and used carelessly they cause skin breakdown and UTI. Choose one on six factors: functional disability, type and severity, gender, caregivers available, earlier treatment failed, and patient preference. Eight types:

Nursing care, any type:

Priority (Exam 3): incontinence is an actual problem and skin breakdown only a risk, so incontinence ranks first.

Retention: urine made but not emptied top-weighted topic

Six causes: an enlarged prostate (men far more often); drugs that block the emptying reflex, such as anticholinergics, antihistamines, antidepressants and opioids (Part 6, What changes voiding); surgery on the lower abdomen or pelvis, especially with an epidural, delayed walking or low intake; swelling after childbirth; nerve damage; and obstruction or prolapse. Immobility lowers bladder tone and leaves urine standing (Exam 2).

The cues: a bladder distended above the symphysis pubis, discomfort, frequent small voids, hesitancy, a weak stream, and dribbling (overflow). The proof is a high PVR: above 100 mL means the bladder is not emptying (Part 6, The bladder scanner). Untreated, retention leads to UTI, hydronephrosis and kidney damage.

Nursing care:

UTI and CAUTI top-weighted topic

UTI is one of the commonest health care–associated infections and a common source of systemic infection in older adults. E. coli from the bowel is the usual organism. A lower UTI is the bladder (cystitis) and urethra; an upper UTI is the kidneys and ureters (pyelonephritis), and an untreated lower UTI can climb there.

Seven risk factors: female anatomy (a short urethra near the vagina and rectum) and sexual activity; a diaphragm or spermicide, which kills protective flora; menopause; an indwelling catheter; diabetes; older age, including an enlarged prostate; and stasis from retention, immobility or habitually putting off voiding.

Nursing care:

Prevention, six points in a patient's words: six to eight 8-oz glasses of fluid a day; go when you first feel the urge and take time to empty fully; wipe front to back; urinate before and after sex; cotton-crotch underwear and no tight clothes; shower rather than bathe, with no douches or sprays. If infections recur, discuss alternatives to a diaphragm or spermicide.

CAUTI. About 75% of hospital UTIs are catheter-associated, and CMS treats CAUTI as preventable and does not pay for its treatment. Bacteria form a biofilm on the catheter and climb inside the lumen or along the outside. The bundle (Exam 1): insert only for a valid indication, with surgical asepsis; maintain it by the seven care rules (Caring for the catheter); remove it as early as possible.

Kidney stones: the calcium bridge top-weighted topic

Refresher (Exam 2): with immobility, calcium leaves demineralising bone and can precipitate as renal calculi. That is the bridge from high serum calcium (Part 3, The links) to this chapter. Other risks include low urine volume, a high urine calcium, hyperparathyroidism, excess calcium or calcium antacids, gout, obesity, diuretics, recurrent UTI, male sex and a prior or family history of stones.

The picture is sharp flank pain radiating to the lower abdomen or groin, hematuria, frequency, urgency and dysuria. A stone can block the outflow and cause retention. Fever and chills mean infection behind an obstruction: report. For a small stone, strain all urine and send any stone to the lab to be identified, push fluids unless restricted, give analgesia as ordered, and track I&O and temperature; a large or obstructing stone is broken up by shock-wave lithotripsy or removed.

Promoting voiding and continence

Habits, five of them: help the patient void when the urge first comes; give privacy unless they are too weak to be left; use their usual position (men standing, women often on a commode; the positioning rules are from Exam 2); stay with anyone who might fall and never lock the bathroom door; and keep fluids up, six to eight glasses a day.

Pelvic floor muscle training (Kegel). It reduces or eliminates stress incontinence and helps every type in women. The patient finds the muscle by imagining stopping urine midstream or holding back stool, then squeezes 5–10 seconds and relaxes 10, with the abdomen, thighs and buttocks relaxed, in sets through the day for at least 3 months. Stopping the stream is for finding the muscle once, not a daily exercise: repeated stop-start voiding can leave urine behind.

Scheduled voiding comes in three forms, and they differ by who runs the schedule:

Two more techniques. Double voiding: void, wait a few minutes or lean forward, then void again, for incomplete emptying. Credé is firm downward pressure over the bladder for a flaccid bladder, used only with an order.

Incontinence-associated dermatitis (IAD). Bacteria turn urea into alkaline ammonia, which raises skin pH and breaks down the barrier. It looks like redness with poorly defined edges, warm and firm, with burning or itching. Inspect the perineum, buttocks and hips daily. Care, in four steps: prevent the incontinence; clean promptly after each episode with a pH-balanced cleanser (not soap and hot water), patting, never rubbing; moisturise, nothing with alcohol; a barrier (zinc oxide, petrolatum or a sealant) on all skin urine can reach, after every episode. Refer to a WOC nurse if it hasn't responded in 2 weeks.

Catheters: when, and which kind top-weighted topic

Every catheter needs an order (Exam 3), and urethral insertion is surgical asepsis (Exam 1). Nurses insert every type except the suprapubic and the coudé. Eight indications: acute retention; long-term drainage when nothing else works (neurogenic bladder); a sterile specimen from a patient who can't void; accurate output in the critically ill; healing an open sacral or perineal wound in an incontinent patient; around some surgery and tests; end-of-life comfort; prolonged immobilisation (unstable spine, multiple trauma). Not indications: managing incontinence, or staff convenience.

Inserting an indwelling catheter, female and male top-weighted topic

Before you open the kit: confirm the order, ask about latex and iodine allergy, get good light (a flashlight needs an assistant), use a firm surface, and get a second person if needed. The lab grades the steps below; the goal line is urine output of at least 30 mL/h with a bladder that is not distended.

Balloon: the checklist's set-up step says a prefilled sterile saline syringe and its inflation step says sterile water; Taylor and ATI use sterile water throughout. Neither the checklist nor Taylor pre-tests the balloon, though older test banks do.

Male, Taylor 10e: lubricate 5–7 in (anaesthetic gel 5–10 mL if used, after an allergy check), hold 3–4 in from the tip, advance 7–10 in until urine, then about 2 in more to the Y. Both versions stop at the Y.

Specimen at insertion: the checklist takes it from the new bag; the deck, Taylor and ATI say the port, never the bag (Part 6). Answer with the port.

Female urethra: Taylor gives 4 cm (1.6 in) in its anatomy section and 1.5–2.5 in in the skill rationale. Use the skill's insertion depths.

Caring for the catheter, and taking it out top-weighted topic

Seven care rules:

1. Meatal care with soap and water daily and after each bowel movement, cleaning the catheter from the meatus outward; no powders, lotions or antiseptics at the meatus.
2. Generous fluids unless restricted: natural irrigation.
3. Constant downward flow: no kinks, no dependent loops, not lying on the tubing.
4. Bag below the bladder at all times, including transport, and off the floor.
5. Keep the system closed. If it comes apart, replace the catheter and the bag.
6. Empty into the patient's own graduated container at least every 8 hours; the spout touches nothing.
7. Report CAUTI signs (UTI table, With a catheter). Change the catheter only when it fails, never on a schedule; remove it as soon as possible.

A leg bag is not a closed system, because it is opened to switch to a night bag; empty it at ½–⅔ full and clean the outlet each time.

Meatal care frequency: Taylor and ATI Engage say daily; ATI Skills Modules say at least once a shift. Follow facility policy.

Three devices with care of their own:

Removal, in five steps:

1. Check the record for the balloon volume; empty and measure the bag.
2. Attach a syringe and let the balloon push the plunger back. Don't pull it, and never cut the tubing.
3. Confirm the volume withdrawn matches the volume charted.
4. Withdraw gently as the patient breathes out; stop and notify if you meet resistance.
5. Perineal care.

After removal: encourage fluids; record intake and the time and amount of every void for 24 hours, voiding into a hat, and the volume of the first void. Slight burning, urgency or frequency on the first void or two is expected, and so is an accident. After a few days of catheter, watch for retention. If the patient hasn't voided within 8–10 hours, or per policy, notify; bladder-scan first if they feel full.

Many NCLEX sources teach 6–8 hours for the first void.

Urinary diversions, stents and dialysis

Stoma assessment. Normal is dark pink to red, moist and shiny, swollen at first and stable in size by about 6–8 weeks. Pale suggests anaemia; dusky, purple or black means poor circulation: notify promptly. Mucus in the urine is expected from any diversion built from bowel. Empty the pouch at ⅓–½ full; change it every 3–7 days, early in the morning before fluids, with the opening cut ⅛ in larger than the stoma and no lotion on the skin.

Stents and dialysis, briefly

Who does what: delegating urinary care

Delegation turns on the judgement a task needs, not how routine it looks (Exam 3); the nurse validates and interprets what assistive personnel measure.

Writing the problem statements

Urinary function can be the problem (incontinence, altered pattern, retention) or the cause of another (anxiety, caregiver role strain, risk for infection). “Catheterization R/T urinary retention” is wrong (Exam 3): a treatment is not a problem, though it can be a cause, as in the last row.

Six planned goals. Output about equal to intake; fluid and electrolyte balance; bladder emptied completely at regular intervals; reports ease of voiding; intact skin; self-care. Make each measurable: not “will void adequately” but “will void at least 200 mL within 8–10 hours of catheter removal, with a PVR under 50 mL”.

Numbers to know cold

Course figures only; another source's number is in grey in its part.

Easy to confuse: the deciding hook

What do you do first

Every option is a correct action; the order is the item. The tempting error is the famous step, or the call, jumping ahead of stopping the cause.

Same finding, two answers

Before you act on a value, find the test, drug, diagnosis or device it belongs to.

Still open: ask the instructor

The first row is flagged “Ask the instructor” where it is taught; the other four are source splits a part has settled for now. Meanwhile, use the third column.

The Chapter 38 deck settled one former split: a catheter specimen comes from the sampling port, never the bag. The instructor's Chapter 41 lecture slides are still to come; this list will be updated once they are posted.