AKI, Dialysis & Fluid Balance | A Decision-Making Sequence Connecting Urine Output, Hyperkalemia, Pulmonary Edema, and Dialysis Complications | MyMerci
제안하기
0 / 2000
Korean English Japanese Traditional Chinese (Taiwan) Vietnamese Malay (Malaysia) Mongolian

AKI, Dialysis & Fluid Balance | A Decision-Making Sequence Connecting Urine Output, Hyperkalemia, Pulmonary Edema, and Dialysis Complications

CHAPTER 04 · Adult Health Nursing · Renal & Fluid AKI, Dialysis & Fluid Balance

Before focusing on a single creatinine value, first read the trends in urine output, perfusion, and fluid status. Then, identify hyperkalemia, acidosis, pulmonary edema, and uremic complications, and safely manage hemodialysis access and peritoneal dialysis infection.

Core Objective: Make clinical judgments in this order: ABCs & Perfusion → Urine Output and Fluid Trends → Reversible Causes → Hyperkalemia, Acidosis, Pulmonary Edema → Renal Replacement Therapy → Dialysis Access & Infection → Treatment Response.

Don't just start fluids because "urine output is low," and don't feel reassured just because a patient "feels tired after dialysis." See the whole picture—respirations, blood pressure, skin perfusion, bladder status, edema, weight, I/O, medications, and changes over time—all together.

A new educational illustration showing a nurse assessing the respiratory and fluid status of a patient with acute kidney injury, along with hyperkalemia monitoring, palpation of a hemodialysis arteriovenous fistula, and checking peritoneal dialysis drainage and infection.
This is a new educational illustration connecting perfusion and fluid status assessment in AKI with hyperkalemia management, hemodialysis access protection, and peritoneal dialysis infection screening. Actual exam questions, answer choices, and source images are not reproduced.

1. Read AKI by the Rate of Change and Threat to Organs, Not Just the 'Creatinine Number'

1 · ABCs and Perfusion

First, check respirations and oxygenation, blood pressure, pulse, skin, and level of consciousness, as well as for shock, sepsis, hemorrhage, and pulmonary edema.

2 · Urine Output Trend

Check hourly urine output and output per body weight, any sudden anuria, catheter patency and bladder distention, and the color, sediment, or presence of blood in the urine.

3 · Fluid Status

Differentiate between fluid deficit and overload using daily weight, I/O, edema, crackles, JVD, mucous membranes, and orthostatic changes.

4 · Cause Classification

Connect the dots between hypoperfusion, intrinsic kidney damage, or urinary tract obstruction with recent medications, contrast dye, surgery, or infection.

5 · Immediate Threats

Screen for hyperkalemia, metabolic acidosis, refractory pulmonary edema, and uremic encephalopathy or pericarditis.

6 · Response and Recovery

Repeatedly compare perfusion, urine output, weight, respiratory status, potassium, acid-base balance, and BUN/creatinine against the prescribed treatment response.

Creatinine may not rise immediately after injury, and not all AKI is oliguric.

The basic KDIGO criteria for recognition are: an increase in creatinine of ≥0.3 mg/dL within 48 hours, an increase to ≥1.5 times baseline within 7 days, or a urine volume of <0.5 mL/kg/h for 6 hours. Even if lab values have only changed slightly, the presence of new-onset oliguria or anuria with decreased perfusion requires an immediate cause evaluation.

2. Categorize Causes as Pre-renal, Intrinsic, or Post-renal, but Tailor Treatment to the Patient's Condition

CategoryKey CluesNursing Connections
Pre-renal / HypoperfusionHemorrhage, dehydration, sepsis, hypotension, low cardiac output, cool skin, orthostatic changesTrack the response to resuscitation of the underlying cause and perfusion, but reassess fluids if crackles, JVD, or edema develop
Intrinsic / Parenchymal DamageProlonged AKI, clues of nephrotoxins, sepsis, rhabdomyolysis, or glomerular diseaseReview medications, dosages, lab results, and urine findings, and report to stop or adjust nephrotoxic exposures
Post-renal / ObstructionAnuria, intermittent urine stream, bladder distention, BPH, stones, tumors, catheter kinkingCheck catheter tubing and position, and verify bladder scan results, imaging, and decompression orders
MixedHypoperfusion and parenchymal damage can occur together, such as in sepsis, heart failure, or post-surgeryDon't fixate on a single cause; continuously re-evaluate hemodynamics, fluid status, medications, and infection response

Oliguria does not automatically equal a fluid bolus.

First, check for catheter kinking, bladder distention, and signs of hypovolemia. When hypoperfusion is suspected and there is no pulmonary edema, administer prescribed isotonic crystalloids and immediately assess the response through blood pressure, peripheral perfusion, urine output, respiratory status, crackles, and JVD. If fluid overload, heart failure, or pulmonary edema is already present, additional fluids can worsen the condition.

Items to Reassess Every Time in AKI

Urine

Hourly amount, weight-based trend, sudden anuria, hematuria, foaminess, sediment, and catheter patency

Fluid Status

Daily weight under the same conditions, accurate I/O, edema, lung sounds, JVD, mucous membranes, orthostatic changes

Lab Work

Potassium, sodium, bicarbonate, BUN/creatinine, glucose, calcium, phosphate, and any prescribed urine studies

Exposures

NSAIDs, ACEi/ARBs, diuretics, aminoglycosides, contrast dye, supplements, and the time of last administration

Diuretics are not a medication that reverses AKI itself. They may be prescribed for the indication of managing fluid overload, but don't assume kidney function has recovered just because urine output increases. Medication dosages should be reviewed based on current kidney function, dialysis timing, blood pressure, and electrolyte levels.

3. Hyperkalemia management follows three steps: “Protect the heart → Shift potassium into cells → Remove it from the body”

1
Quickly check the specimen and ECG

Consider the possibility of a hemolyzed sample, but if you see muscle weakness, bradycardia, arrhythmias, or ECG changes, don’t delay treatment while waiting for a repeat lab draw. A normal ECG doesn’t completely rule out dangerous hyperkalemia either.

2
If ECG changes are present, protect the myocardium first

Prepare the prescribed IV calcium right away. Calcium lowers the risk of arrhythmias but doesn’t actually lower the serum potassium level, so the next steps absolutely must follow.

3
Shift potassium into the cells

Administer insulin and glucose, and if needed, an inhaled beta-agonist according to your institutional protocol. In renal failure, insulin’s effect can be prolonged, so monitor repeatedly for delayed hypoglycemia.

4
Remove potassium from the body

Depending on renal function and volume status, coordinate diuresis, a potassium binder, or dialysis. The shifting treatments are only temporary, so recheck potassium, ECG, and glucose to watch for rebound.

Don’t just wait for a peaked T wave

The ECG in hyperkalemia doesn’t always follow a predictable sequence. Look at the whole clinical picture and potassium trend, including any new QRS widening, conduction delay, bradycardia, or arrhythmia. Even if the ECG looks better after calcium, that doesn’t mean the potassium has been eliminated.

4. The decision for dialysis or renal replacement therapy isn’t based on a single number — it’s based on refractory, life-threatening organ compromise

Indication axisRed flagsNursing actions
AcidosisSevere metabolic acidosis unresponsive to medical managementCheck ABG/VBG, bicarbonate, respiratory status, hemodynamics; contact the renal and critical care teams
ElectrolytesHyperkalemia or arrhythmias that don’t respond to treatment or keep recurringCardiac monitoring, immediate treatment, and prepare for dialysis access, consent, and equipment
FluidRefractory pulmonary edema or fluid overload with worsening oxygenationElevate the head of bed, monitor oxygenation, blood pressure, weight, I/O, and assess for urgent ultrafiltration
UremiaUremic pericarditis, encephalopathy, bleeding tendency, or severe symptomsWatch for chest pain, friction rub, altered mental status, seizures, bleeding; prompt specialist team evaluation
ToxinsExposure to a dialyzable toxin with deteriorating systemic conditionIdentify the substance, time, and amount; coordinate with poison control and the renal team for detoxification and dialysis route

Don’t decide to start dialysis based on a single BUN, creatinine, or potassium value alone.

KDIGO and NICE recommend urgently considering renal replacement therapy when there are life-threatening changes in fluid, electrolytes, or acid-base balance. The decision to start is based on the patient’s overall condition, trends over time, and response to treatment.

5. For hemodialysis, connect the baseline picture before, during, and after the session

TimingWhat to checkChanges you can’t afford to miss
Pre-dialysisWeight under the same conditions, vital signs and orthostatic changes, lung sounds and edema, potassium and glucose, access thrill/bruit, and skinPulmonary edema, hyperkalemia, infection, loss of access blood flow, and medications that need to be adjusted before dialysis
During dialysisBlood pressure, heart rate, level of consciousness, chest pain, dyspnea, cramping, nausea, machine alarms, and access site bleedingHypotension, arrhythmias, air or blood loss, severe cramping, fever, and chills
Post-dialysisWeight, vital signs and orthostatic safety, respiratory status and edema, needle site hemostasis, thrill/bruit, and distal perfusionPersistent hypotension or syncope, dyspnea, uncontrolled bleeding, and new headache, confusion, or seizures

AV fistula & graft

Look, listen, and feel: check the skin, bruit, thrill, and the color, temperature, and sensation of the distal extremity. If there’s any change or loss of these findings, don’t use the access and report it immediately.

Protect the arm

Avoid blood pressure measurements, venipuncture, IV lines, tight clothing, heavy pressure, or sleeping on that arm. Share the access location with a bracelet and during handoff.

Needle sites

After needle removal, apply direct pressure to each site individually, but don’t occlude the entire access flow. If bleeding persists, call for emergency help.

Dialysis catheter

Follow aseptic technique and your institutional protocol when connecting, disconnecting, and changing the dressing at the hub. Immediately report any moisture, contamination, redness, drainage, or fever.

Don’t automatically dismiss post-dialysis fatigue as “normal.”

First, check the blood pressure, orthostatic changes, oxygenation, heart rhythm, access site bleeding, and weight change. Dyspnea, chest pain, syncope, persistent hypotension, or new neurological changes are not just routine fatigue.

6. For peritoneal dialysis, check the inflow, dwell, drainage, and “is it clear?” at every exchange

1
Create an infection barrier before the exchange

Make sure you have a clean, dry space, perform hand hygiene and wear a mask, and use aseptic technique at the connection site. Check the solution’s expiration date, concentration, any leaks or cloudiness, and verify it against the prescription, then warm it to near body temperature using an approved method.

2
Observe the inflow and dwell

Watch for pain, shortness of breath, leaks, and the inflow rate. Never use a microwave or hot water to heat the solution yourself, and don’t add anything to the solution unless it’s prescribed.

3
For drainage, check the volume, color, clarity, and time

Document the prescribed fill volume, the amount that drained out, how clear it is, any fibrin or blood, and note any abdominal pain, fever, nausea, and the condition of the exit site.

4
If the fluid is cloudy, start the peritonitis pathway

If you see cloudy effluent or new abdominal pain, save the drained fluid to send for cell count with differential, Gram stain, and culture, and report it immediately. Don’t delay treatment while waiting for culture results.

If the drainage is slow: Check for clamps, kinks, the position of the bag, and the tubing, and try changing the patient’s position. Assess for possible constipation, catheter migration, fibrin, or obstruction, but don’t forcefully milk the catheter or irrigate it without a prescription. If new pain, cloudiness, or fever is present, don’t assume it’s just a simple positioning problem.

Don’t “just watch and wait until the cloudy effluent is definite” when it comes to peritonitis.

The ISPD recommends treating cloudy effluent as peritonitis and starting the diagnostic and treatment pathway. A diagnosis is made when at least two of the following are present: effluent WBC count and differential, symptoms, and culture results. After collecting the specimen, promptly connect to your institution’s protocol for empiric antibiotics.

7. Fluid and diet plans are tailored to the patient’s current elimination ability and dialysis modality, not just their diagnosis

Focus AreaAssessmentTeaching Principles
Fluid & NaResidual urine output, interdialytic weight gain, edema, blood pressure, thirstPersonalize the prescribed limits, teach about hidden fluids and salty foods, and encourage daily record-keeping
KCurrent K level, ECG and medications, dialysis interval, constipation, and dietary patternsAlign the plan with lab results and a dietitian’s guidance rather than permanently banning a single food
PhosphatePhosphate, Ca, PTH levels, binder prescription and timing of administrationTeach about phosphate additives in processed foods and link binder use directly to meals
ProteinCatabolic state in AKI, dialysis modality, wounds, infection, albumin level, and intakeAvoid a blanket low-protein ban, as needs vary by situation, such as protein loss in PD

You can’t explain everything with a single “renal diet” handout

The fluid, K, phosphate, and protein requirements differ for AKI, conservative CKD management, hemodialysis, and peritoneal dialysis. PD, in particular, can lead to protein loss. Always plan care with a renal dietitian based on the most recent labs, residual kidney function, dialysis prescription, and any comorbidities.

8. Independent judgment practice

The examples below are newly created scenarios for practicing your clinical judgment flow and do not reproduce actual NCLEX questions, answer choices, or correct answers.

Example A · During sepsis treatment, urine output drops and new crackles with a positive fluid balance develop

First: Reassess oxygenation, blood pressure, perfusion, weight, I/O, and check the bladder and catheter, then report the fluid overload, cardiac function, and AKI progression. The team will re-evaluate the need for additional fluids, diuretics, blood pressure support, and renal replacement therapy.

What you wouldn’t do: Don’t just keep repeating the same fluid bolus simply because the patient is oliguric.

Example B · Rising K level appears with QRS widening and bradycardia

First: Secure cardiac monitoring and emergency help, protect the myocardium with prescribed IV calcium, then concurrently start cellular shift treatments like insulin and glucose along with a K removal pathway. Repeat the K, ECG, and glucose checks.

What you wouldn’t do: Don’t just give calcium and then assume the K level has been lowered.

Example C · A patient who missed dialysis arrives with severe hypertension, crackles, and hypoxia

First: Raise the head of the bed, check oxygenation, cardiac monitoring, K, and ECG, and open the pathway for pulmonary edema resuscitation and urgent dialysis/ultrafiltration.

What you wouldn’t do: Don’t just “wait for the next scheduled dialysis” or finish up with only a routine diuretic.

Example D · The usual thrill over an AV fistula is no longer palpable

First: Do not use the access. Check for a bruit, skin condition, pain, swelling, and distal perfusion, and report immediately to the dialysis or vascular team.

What you wouldn’t do: Don’t try to insert a needle to test patency or compress the arm with a blood pressure cuff.

Example E · After hemodialysis, a patient says “I’m tired” and complains of dyspnea and dizziness

First: Assess vital signs, orthostatic safety, oxygenation, heart rhythm, weight change, and check the access site for bleeding to rule out hypotension, arrhythmia, or residual pulmonary edema.

What you wouldn’t do: Don’t just dismiss it as common post-dialysis fatigue and send the patient home right away.

Example F · PD drainage is cloudy and new abdominal pain appears

First: Do not discard the drainage — save it to prepare for cell count, differential, Gram stain, and culture, and report it immediately. Assess vital signs, abdomen, and exit site, and connect to empiric treatment.

Don't: Don't wait until the next exchange or try to resolve it with just fluid intake.

Example G · Patient has a catheter but almost no urine for 4 hours and the lower abdomen is distended

First: Check for tubing kinks, dependent loops, and bag position, and connect to a bladder scan and catheter patency orders. After resolving the obstruction, monitor for sudden large-volume urination and electrolyte changes.

Don't: Don't assume it's renal parenchymal damage and flush the catheter without assessment.

9. Common Pitfalls

The trap of directly linking one signal to one intervention

  • Ignoring new oliguria just because creatinine is still within normal range.
  • Assuming all AKI presents with oliguria and hyperkalemia.
  • Giving fluids first when urine output is low without checking for fluid overload.
  • Thinking calcium removes serum K⁺ and skipping rechecks.
  • Judging there's no hyperkalemia risk because the ECG is normal.
  • Deciding to start dialysis based on a single BUN or creatinine value.
  • Taking blood pressure, drawing blood, or starting an IV in the access arm, or cannulating when the thrill is absent.
  • Dismissing post-dialysis dyspnea or syncope as routine fatigue.
  • Discarding cloudy PD effluent and just observing until the next exchange.
  • Applying the same low-protein, low-K⁺, fluid restriction to every renal patient.

10-Second Check to Recall in the Exam Room

AKI

Trends in ABCs, perfusion, urine output, fluid status, bladder, medications

Hyperkalemia

ECG, myocardial protection, shifting into cells, removing from body, recheck

Dialysis Indications

Refractory acidosis, electrolytes, pulmonary edema, uremia, toxins

Hemodialysis

Weight, blood pressure, access, bleeding, hypotension, breathing

Peritoneal Dialysis

Aseptic technique, inflow, dwell, drainage, cloudiness, abdominal pain

Diet

Individualized by labs, residual renal function, and dialysis modality

Evidence Scope: Independently written in August 2026 based on the Reduction of Risk Potential and Physiological Adaptation judgment domains of the 2026 NCSBN RN Test Plan, KDIGO AKI and Acute Hyperkalemia reports, NICE AKI guidelines, UK Kidney Association hyperkalemia guidelines, KDOQI vascular access resources, NIDDK dialysis information, ISPD peritonitis guidelines, and CDC dialysis infection prevention recommendations.

NCSBN 2026 RN Test Plan · KDIGO AKI Guideline · NICE Acute Kidney Injury

KDIGO Acute Hyperkalemia Report · UKKA Acute Hyperkalaemia Guideline · KDOQI Vascular Access

NIDDK Hemodialysis · NIDDK Peritoneal Dialysis · ISPD Guidelines · CDC Dialysis Infection Prevention

Content Boundaries: Only recurring study topics were identified from local feedback materials. Actual exam questions, answer choices, correct answers, screens, patient information, source images, and tables were not copied or reproduced. All explanations, cases, judgment sequences, tables, and illustrations were newly written and created.

This material is a summary for nursing exam study and does not replace actual patient diagnosis or treatment orders. In clinical practice, follow the latest lab results, prescriptions, dialysis modalities, vascular access, infection control, hyperkalemia protocols, and the judgment of the renal and critical care specialist team.

다음 이론을 계속 학습하려면 로그인하세요.

로그인하고 계속 학습
컨텐츠를 그만볼래?

필기노트, 하이라이터, 메모는 잘 쓰고 있어?

내보내줘
어떤 폴더에 저장할래?

컨텐츠 노트에는 총 0개의 폴더가 있어!

폴더 만들기
컨텐츠 만들기
만들기
신고했어요.

운영진이 검토할게요!

해당 유저를 차단했어요.

마이페이지에서 차단한 회원을 관리할 수 있어요.