Applied Nephrology Master Series

Chapter 19

Integrated Troubleshooting:
From Clinical Problem to Prescription Change

CHAPTER MISSION Convert the entire PD volume into one bedside reasoning system. For any new symptom, alarm, abnormal effluent, volume problem, biochemical drift or treatment-burden signal, identify the safety priority, verify what was actually delivered, localize the dominant failure domain, name the mechanism, make the smallest corrective change, and define how success will be reassessed.

Figure 19.1 — The eight-decision troubleshooting loop. The clinician moves from safety and phenotype to validation, localization, mechanism, targeted correction, reassessment and escalation.

MASTER PRINCIPLE Do not change the PD prescription until you can state what problem you are treating and which mechanism the change is expected to correct. If the mechanism is uncertain, gather the next discriminating piece of information rather than escalating therapy by reflex.

0. One-page chapter map

Table 19.1 — The eight decisions that govern integrated PD troubleshooting.

Decision	Core question	Bedside output
1. Safety	Is there a time-critical threat independent of the PD mechanism?	Urgent stabilization/escalation
2. Phenotype	What exactly changed: symptom, bag appearance, alarm, weight, BP, lab or delivered treatment?	Problem stated precisely
3. Validate	Was therapy delivered, measured and documented correctly?	Real problem separated from data/delivery artifact
4. Localize	Which domain is failing: delivery, access, infection, membrane/prescription, patient physiology or support?	Failure domain named
5. Mechanism	What causal pathway best explains the phenotype?	Mechanistic diagnosis
6. Correct	What is the smallest effective change that treats that mechanism?	Targeted intervention
7. Verify	What symptom, treatment metric, examination or laboratory change should improve?	Reassessment endpoint
8. Escalate	If unresolved or unsafe, what specialist, procedure, imaging, hospitalization or HD-transfer plan is needed?	Safe next level of care

Learning outcomes

Use a single troubleshooting sequence across common PD complaints without collapsing every problem into “more dialysis.”
Distinguish data/delivery failure from catheter mechanics, infection, membrane dysfunction, prescription mismatch, systemic illness and treatment-burden problems.
Recognize time-critical patterns that require urgent assessment before routine PD troubleshooting.
Build a differential from the phenotype of poor drainage, low ultrafiltration, volume overload, inadequate clearance, pain or abnormal effluent.
Choose prescription levers by mechanism—time, volume, osmotic strategy, drain strategy, RKF/medication plan or support—not by habit.
Define a reassessment endpoint before making a PD change and avoid simultaneous multi-variable changes that obscure cause and effect.
Integrate recurrent infection, mechanical dysfunction, membrane failure, nutrition decline, frailty and caregiver burden into multidomain decision-making.
Use the 2026 ISPD terminology of HD transfer and document immediate and contributing causes when PD can no longer be delivered safely or sustainably.

EVIDENCE POSTURE This chapter is a synthesis rather than a new disease-specific guideline. It is anchored in the current ISPD goal-directed prescribing framework, 2021 membrane-dysfunction recommendations, 2022 peritonitis guideline, 2023 catheter-related infection update, 2019 PD-access guideline and the 2026 ISPD statement on loss from PD therapy. Contemporary adequacy/prescription guidance, PDOPPS outcome data and training/CQI literature are used to support integration. Disease-specific thresholds remain in their dedicated chapters and are not reinvented here. [1–12]

1. Troubleshooting is a localization problem, not a prescription problem

A PD complaint often arrives as an output: “the machine alarmed,” “the drain is low,” “I am swollen,” “the fluid is cloudy,” “the creatinine rose,” or “I cannot do this anymore.” These statements are clinically useful only after they are translated into a failure domain. Increasing glucose, adding cycles or extending treatment time may improve one output while worsening the actual problem—for example, more intraperitoneal pressure in a leak, more glucose burden in a patient with metabolic toxicity, or longer nocturnal treatment in a patient whose main problem is recurrent drain pain and sleep disruption.

Figure 19.2 — Six domains of PD failure. Most PD problems can be localized to delivery/data, access/mechanics, infection/inflammation, membrane/prescription, patient physiology, or capability/support.

Table 19.2 — Complaint to failure-domain translation.

What the patient/team reports	First domains to test	Do not assume
“My UF is low.”	Delivery/drain mechanics; intake/RKF; prescription; membrane	Membrane failure
“I am gaining weight.”	Sodium/water balance; glucose calories; edema; RKF; adherence/support	All weight gain is fluid
“The cycler keeps alarming.”	Drain mechanics; setup; position; constipation; device/data	Catheter needs replacement
“My bag is cloudy.”	Peritonitis first; then noninfectious mimics	Culture-negative means noninfectious
“I feel weak and nauseated.”	Uremia; volume; electrolytes; infection; nutrition; medications	Kt/V alone explains symptoms
“PD is too much.”	Treatment burden; cognition; caregiver; sleep; symptoms; depression	Nonadherence
“Blood pressure is high.”	Volume; sodium; medications; pain/stress; measurement quality	More dextrose is the first step
“Clearance is low.”	Collection/delivery error; RKF loss; prescription; membrane transport	Immediate maximal dose escalation

LOCALIZATION RULE The first useful sentence in a PD troubleshooting note is not “increase dialysis.” It is “the dominant problem appears to be ___ because ___.”

2. First-pass safety screen: identify what cannot wait

Integrated troubleshooting begins by separating a stable home-therapy problem from a medical emergency. PD should not delay resuscitation, urgent laboratory correction, imaging, surgery or transfer to an appropriate acute-care setting. Some dangerous presentations are caused by PD; others simply occur in a person receiving PD. The clinician must recognize both.

Table 19.3 — Safety screen before routine troubleshooting.

Red-flag phenotype	Potential threat	Immediate direction
Severe generalized or focal abdominal pain, guarding, shock	Peritonitis, perforation, ischemia, obstruction, bleeding	Urgent clinical/surgical assessment; sample effluent when appropriate
Cloudy effluent with systemic illness	PD peritonitis / sepsis	Chapter 10 pathway without delay
Acute dyspnea, hypoxemia, large new effusion	Pulmonary edema, hydrothorax, pneumonia, PE, cardiac event	Direct acute evaluation; do not manage from UF data alone
Severe hyperkalemia or acid-base instability	Life-threatening biochemical emergency	Stabilize and provide adequate KRT; modality choice follows urgency
Tender irreducible hernia / vomiting / obstruction	Incarceration/strangulation or EPS/other obstruction	Urgent surgical pathway
Heavy or persistent hemoperitoneum with hemodynamic change	Intra-abdominal or gynecologic bleeding	Urgent diagnostic assessment
Fever + tunnel/exit-site findings + peritonitis features	Deep catheter infection with intraperitoneal spread	Chapter 10/11 source-control pathway
Rapid functional/cognitive decline affecting sterile technique	Immediate home-treatment safety risk	Assisted pathway, temporary supervision or modality reassessment

SAFETY BOUNDARY A “PD problem” becomes an acute medical problem whenever physiology, infection severity, bleeding, respiratory compromise or surgical features make remote or routine troubleshooting unsafe.

3. Validate the treatment before interpreting the physiology

The most common avoidable reasoning error is to interpret a number before confirming how it was produced. Delivered dialysis can differ from prescribed dialysis because of alarms, early termination, skipped exchanges, unrecorded manual exchanges, wrong solution, short dwells, retained intraperitoneal volume, poor drain or data-transfer failure. Clearance collections can be incomplete. Weight and blood pressure can be measured inconsistently. A reported urine volume may be estimated rather than measured. Validation is not clerical work; it determines whether the physiological inference is valid. [1,7]

Table 19.4 — Data validation checklist.

Data stream	Validation questions	Common false inference
APD treatment	Start/stop time? cycles completed? alarms/bypasses? actual fill/drain?	“Prescription failed” when it was not delivered
CAPD log	All exchanges performed? dwell timing? correct bags?	Assuming planned schedule equals delivered schedule
Net UF	Was initial drain/retained volume handled correctly? any leak?	Calling retained or leaked dialysate membrane UF failure
Weight	Same scale, timing, clothing, fill state?	Treating measurement noise as fluid gain
Blood pressure	Correct cuff/position/rest? trend vs single reading?	Escalating volume therapy from a single poor measurement
Urine/RKF	Measured collection? interval correct? major diuretic/illness change?	Assuming silent RKF stability
Adequacy collection	Complete urine/dialysate collection and correct timing?	Dose escalation for collection error
Remote upload	Connected and complete? manual exchanges visible?	Calling missing connectivity nonadherence

DELIVERED-THERAPY RULE Prescribed therapy is an intention. Troubleshooting uses delivered therapy.

4. Poor inflow, poor outflow and repeated drain alarms

Flow dysfunction is solved by separating external/setup problems, reversible extrinsic compression, intraluminal obstruction, catheter displacement and tissue entrapment. Constipation remains one of the most common reversible causes and should be actively sought. A distended bladder can also impair function. Fibrin or blood can obstruct the lumen. Persistent positional dysfunction, migration, omental wrapping, adhesions or kinking require imaging and procedural expertise rather than repeated prescription escalation. The detailed access pathway is in Chapters 5 and 12. [5]

Flowchart 19.3 — Poor drain, slow flow or incomplete APD. Correct reversible extrinsic causes first, then escalate persistent lumen/tip problems through the Chapter 12 mechanical pathway.

Table 19.5 — Flow phenotype → likely mechanism → next discriminator.

Pattern	Think first	Next discriminator
Good inflow, poor outflow	Constipation, position, tip migration, omentum	Bowel history, posture response, imaging if persistent
Poor inflow + poor outflow	Kink, clamp/transfer set, fibrin/clot, severe malposition	External inspection + lumen assessment
Sudden dysfunction after blood/fibrin	Intraluminal obstruction	Visible fibrin/blood; protocolized catheter assessment
Works only in one position	Tip position / entrapment	Reproducible posture effect; imaging
Repeated APD drain alarms but manual drains okay	Cycler pressure/drain dynamics, posture, tidal strategy	Event log + manual functional comparison
Low drain with edema/swelling near catheter or genitalia	Leak rather than “retained UF”	Physical exam + leak imaging when indicated
Poor drain + fever/cloudy fluid	Peritonitis/inflammation plus mechanics	Parallel infection work-up
Persistent dysfunction despite conservative correction	Migration, omentum, adhesions, kink	Fluoroscopic/laparoscopic salvage pathway

MECHANICAL PITFALL Do not compensate for incomplete drainage by increasing glucose concentration, exchange number or treatment time. That can increase retained volume and intraperitoneal pressure while leaving the mechanical cause untreated.

5. Low ultrafiltration, weight gain and edema

“Low UF” is not a diagnosis. First ask whether dialysis was delivered and drained, whether fluid is leaking, whether sodium and fluid intake changed, whether residual kidney function declined, and whether the prescription matches the patient’s transport physiology. Only after these are addressed should persistent low ultrafiltration be classified with formal membrane assessment as described in Chapters 3, 8 and 14. ISPD goal-directed prescribing explicitly requires volume, symptoms, RKF, delivered therapy and patient priorities to be interpreted together rather than reducing adequacy to a single number. [1,2]

Flowchart 19.2 — Low UF, weight gain or edema. Separate delivery/mechanical problems, systemic volume causes, prescription mismatch and true membrane dysfunction before escalating osmotic exposure.

Table 19.6 — Volume troubleshooting matrix.

Finding	Mechanism candidates	Useful discriminators	Direction
Low net UF + repeated drain alarms	Incomplete drainage / constipation / migration	Event log, retained volume, bowel/posture response	Mechanical pathway
Low UF + genital/wall edema	Dialysate leak	Exam, fill-volume relation, imaging when needed	Pressure reduction + source correction
Weight ↑ + edema + urine ↓	RKF loss + sodium/water accumulation	Measured urine, medications, intake	Rebuild total volume plan
Weight ↑ without edema	Glucose calories / nutrition / adiposity	Glycemia, intake, longitudinal body composition	Metabolic rather than UF escalation
Hypertension + weight ↑ + UF trend ↓	Likely congestion but confirm	Symptoms, exam, urine, intake, prescription	Volume strategy
Dyspnea + unilateral effusion	Hydrothorax / noncardiac effusion	Chest imaging ± pleural evaluation	Chapter 12 pathway
Persistent UF problem despite good drainage	Prescription mismatch or membrane dysfunction	PET/UF-capacity assessment per guideline	Chapters 3/8/14
Frequent hypertonic glucose use	Refractory volume problem or prescribing habit	Why high glucose is needed; metabolic cost	Mechanism-based redesign

VOLUME RULE Treat the volume phenotype, not the UF number. A patient can have low UF without clinical overload, or overload despite apparently acceptable UF when sodium intake, RKF loss or cardiac disease dominates.

6. Hypertension, hypotension, dizziness and cramps

Blood-pressure abnormalities in PD should be interpreted as hemodynamic phenotypes, not automatic instructions to change dialysate strength. Hypertension can reflect extracellular volume excess, sodium intake, medications, sympathetic activation, pain or measurement error. Hypotension and dizziness may follow excessive fluid removal, poor intake, autonomic dysfunction, infection, bleeding or cardiac disease. The prescription change must follow the mechanism.

Table 19.7 — BP symptom troubleshooting.

Phenotype	High-probability questions	PD-specific response
Hypertension + edema/weight gain	Sodium, urine decline, missed/short treatments, UF pattern	Chapter 8 volume redesign after validation
Hypertension without congestion	Medication, pain, sleep, measurement technique	Do not force osmotic UF without volume evidence
Dizziness + weight loss	Excess fluid removal, low intake, diuretics, acute illness	Reassess dry-state assumptions and osmotic intensity
Hypotension during/after drains	Volume depletion, cardiac/autonomic disease, pain/vagal response	Clinical assessment; reduce harmful fluid removal if confirmed
Cramps with strong dextrose	Rapid/excessive fluid removal or electrolyte issue	Review osmotic exposure and electrolytes
BP variability in frailty/diabetes	Autonomic dysfunction, medication timing, inconsistent volume	Use trends and symptoms; individualize goals

PRESSURE DISCIPLINE A BP value is a clue, not a prescription. Confirm volume phenotype and competing causes before using PD to chase the number.

7. “Inadequate dialysis”: symptoms, clearance and biochemical drift

Troubleshooting inadequate dialysis begins with the clinical question: what patient-important problem is not controlled? Uremic symptoms, hyperkalemia, acidosis, phosphate burden, appetite decline, volume overload and declining life participation are not interchangeable. A low measured clearance should trigger validation of the collection, assessment of delivered therapy and RKF, and review of transport/prescription before dose escalation. Conversely, acceptable numerical clearance does not dismiss persistent symptoms that require another explanation. [1,7]

Table 19.8 — Inadequacy phenotype → mechanism.

Problem	Check before increasing PD dose	Potential lever
Low measured clearance	Collection completeness, delivered exchanges, RKF, body-water estimate	Time/cycles/dwell strategy if truly needed
New nausea/anorexia	Volume, infection, medications, constipation, nutrition, uremia	Treat dominant cause; dose only if uremic mechanism likely
Hyperkalemia	Diet, medications, constipation, missed/incomplete therapy, acidosis	Correct cause + ensure adequate dialysis
Persistent acidosis	Delivery, diet/protein, residual function, intercurrent illness	Prescription/medical correction
Phosphate burden	Dietary bioavailability, binders/adherence, residual function, dialysis exposure	Integrated nutrition/medication/dialysis plan
Fatigue	Anemia, sleep, depression, infection, frailty, volume, uremia	Avoid using clearance as universal explanation
Loss of RKF	Measured urine/clearance trend	Recalculate total therapy rather than react to serum creatinine alone

GOAL-DIRECTED RULE Adequacy is not a rescue number. The question is whether the whole treatment plan controls symptoms, volume, metabolic needs and life goals with acceptable burden. [1]

8. Pain: fill pain, drain pain, abdominal pain and pressure pain

Pain must be classified by timing and relation to the exchange. Infusion pain suggests solution temperature/pH/osmolality, rapid inflow, catheter-tip irritation or intraperitoneal pathology. Drain pain is commonly related to catheter-tip suction against pelvic structures or low residual volume, particularly during APD, but constipation and malposition can contribute. Diffuse abdominal pain—especially with cloudy effluent or systemic features—must be treated as possible peritonitis until evaluated. Focal severe pain or peritoneal signs demand a broader abdominal differential.

Table 19.9 — Pain localization.

Timing/pattern	Think	Next action
Pain during inflow	Solution/temperature/flow, catheter irritation, inflammation	Check setup/solution; examine; infection pathway if suspicious
Pain late in drain	Suction/drain pain, low residual volume, catheter position	Review drain settings/tidal options and mechanics
Pain only upright/full abdomen	Pressure-related mechanical problem	Fill-volume/hernia/leak assessment
New diffuse pain + cloudy effluent	Peritonitis	Chapter 10 now
Focal pain + guarding/vomiting	Surgical/enteric pathology	Urgent imaging/surgical review
Pain + bloody effluent	Hemoperitoneum / abdominal or gynecologic cause	Chapter 13 assessment
Chronic pain + treatment burden	Mechanical symptom + psychosocial burden	Treat mechanism and simplify regimen where possible

PAIN RULE Timing is a diagnostic test. Ask whether the pain starts with fill, during dwell, at end-drain, with posture, or independently of PD.

9. Cloudy, bloody, milky or otherwise abnormal effluent

Cloudy effluent remains infectious until peritonitis is appropriately assessed; the 2022 ISPD diagnostic and treatment framework governs this pathway. Noninfectious abnormalities—hemoperitoneum, eosinophilic reactions, fibrin, chylous effluent, chemical inflammation or biliary/enteric contamination—are considered only after the clinical safety context is clear. Chapter 10 contains the peritonitis criteria and organism-specific management; Chapter 13 contains the noninfectious effluent differential. [3]

Flowchart 19.4 — Pain, cloudy or abnormal effluent. Infection and surgical disease are safety-first branches; noninfectious mimics are localized only after those threats are addressed.

Table 19.10 — Abnormal bag: rapid routing.

Appearance/setting	Priority	Route
Cloudy + pain	Peritonitis	Chapter 10
Cloudy without pain	Still assess peritonitis; consider mimics by differential	Chapter 10 → Chapter 13 if excluded
Pink/red after procedure or gynecologic timing	Hemoperitoneum often benign but context-dependent	Chapter 13; escalate if persistent/heavy/systemic
Milky/white	Chyle vs infectious cloudiness	Triglyceride/cell/culture evaluation as indicated
Fibrin strands	Inflammation, blood, postoperative state	Assess infection/bleeding and catheter patency
Green/brown/bile-like	Enteric/biliary pathology	Urgent abdominal assessment
New unusual odor/color + systemic illness	Contamination, infection, enteric source	Do not reassure from appearance alone

CLOUDY-BAG RULE When cloudiness is present, do not let an attractive noninfectious explanation delay appropriate peritonitis assessment. [3]

10. Exit-site and tunnel abnormalities

The catheter exit site is a source-control question, not simply a skin-care problem. Purulent drainage is central to the ISPD definition of definitive exit-site infection; erythema alone is not equivalent to infection. Tunnel pain, induration, swelling or ultrasound abnormalities increase concern for deeper disease. Recurrent or refractory infection changes the catheter-salvage threshold and may coexist with peritonitis. Chapter 11 contains the full definitions, antibiotic-duration logic and intervention options. [4]

Table 19.11 — Catheter-site routing.

Finding	Interpretation	Action direction
Purulent exit-site drainage	Definitive ESI phenotype	Culture + guideline-directed treatment
Erythema only	Trauma/dermatitis/early infection possible	Examine trend; do not automatically label ESI
Tunnel tenderness/induration	Tunnel infection possible	Clinical + ultrasound assessment
Same organism in catheter infection + peritonitis	Linked source more likely	Lower source-control threshold
External cuff extrusion + persistent infection	Foreign-body/source issue	Catheter intervention pathway
Repeated infection despite appropriate therapy	Biofilm/deep disease/organism issue	Reassess anatomy, microbiology and source control

SOURCE-CONTROL RULE Repeated antibiotics without re-localizing the source is not troubleshooting.

11. Metabolic and nutrition signals: hyperglycemia, weight gain, hypokalemia and PEW

The PD prescription is also a metabolic exposure. Hyperglycemia and weight gain may reflect glucose absorption; hypokalemia may reflect low intake, gastrointestinal loss, insulin effect or medications; appetite decline and low albumin require evaluation for inflammation, infection, undernutrition, fluid status and protein losses. Chapter 13 handles noninfectious metabolic complications and Chapter 15 provides the nutrition/PEW framework. The troubleshooting task is to avoid solving one problem by worsening another—for example, escalating hypertonic glucose in a patient with recurrent metabolic burden when the actual low-UF cause is constipation or leak.

Table 19.12 — Metabolic troubleshooting.

Signal	Do not assume	Check
Glucose rises after PD intensification	Diabetes “progression” alone	Dialysate glucose exposure, illness, medication plan
Weight gain	Fluid overload alone	Edema/volume vs caloric gain
Hypokalemia	Dietary restriction is appropriate	Intake, diarrhea, insulin, diuretics, magnesium, infection risk
Albumin falls	Protein intake alone	Inflammation, peritonitis, volume, protein losses, liver disease
Poor appetite	Uremia alone	Constipation, infection, depression, glucose satiety, GI disease
PEW/frailty pattern	More dialysis always helps	Treatment burden, inflammation, intake, RKF, goals

METABOLIC TRADE-OFF Every osmotic strategy has a metabolic price. Escalate glucose only when it treats the mechanism you have actually identified.

12. Treatment burden, capability and the “nonadherence” trap

A technically correct prescription can fail in practice because it exceeds the patient’s or caregiver’s capacity. Recurrent missed exchanges, early APD termination, contamination, alarm fatigue or reluctance to use prescribed solutions may reflect pain, cognitive change, poor vision/dexterity, work or sleep disruption, caregiver burnout, cost, supply problems or misunderstanding. The 2025–2026 training literature emphasizes repeated competency assessment and support rather than assuming one-time training is permanent. [8]

Table 19.13 — When the prescription is not being delivered.

Observed pattern	Possible hidden cause	Response
Missed exchanges	Work/life burden, depression, misunderstanding	Nonjudgmental cause-finding; simplify/assist
Cycler stopped early	Drain pain, alarms, sleep disruption	Event-log + symptom review; mechanical/prescription correction
Wrong bag/concentration used	Complex regimen / label confusion / vision	Simplify; retrain; caregiver support
Repeated contamination	Technique drift, cognition, home environment	Competency reassessment + retraining/support
No data upload	Connectivity/device failure	Verify before labeling nonadherence
Caregiver no longer available	Support failure	Assisted-PD/social plan or modality reassessment
Patient says “I cannot continue”	Treatment burden/goals have changed	Shared decision-making, redesign or planned transition

LANGUAGE RULE Use “delivered treatment differs from the plan” before using “nonadherent.” The cause may be clinical, mechanical, cognitive, social or system-level—and therefore correctable.

13. Hospitalization and acute illness: the baseline PD prescription may no longer fit

Acute illness changes the assumptions behind a home prescription. Oral intake, glycemia, blood pressure, urine output, ventilation, medications, nutrition and bowel function can change rapidly. Procedures may interrupt exchanges; supine immobilization can alter drain behavior; constipation and opioids are common; infection may change membrane transport. Chapter 17 contains the detailed inpatient and acute-care pathways. The troubleshooting principle is to re-state the current clinical goal rather than automatically reproducing the home prescription.

Table 19.14 — Inpatient reset questions.

Question	Why it matters
What is the current KRT goal?	Volume, potassium, acid-base, solute control or maintenance may dominate
What changed since home?	Acute illness can invalidate the prior prescription
Can PD be delivered safely now?	Surgery, ventilation, leaks, abdominal pathology or instability may limit PD
Is bowel function adequate?	Constipation can create mechanical failure
What medications/fluids are being given?	Hospital inputs may overwhelm home volume assumptions
What is urine output today?	RKF may fall rapidly during acute illness
Who is managing sterile technique?	Staff unfamiliarity can introduce risk
What is the escalation threshold?	Temporary HD/CRRT may be appropriate for acuity, not a permanent modality judgment

INPATIENT RULE A hospitalized PD patient needs a fresh prescription purpose, not an automatic copy of the home cycler program.

14. Multidomain failure: when one problem is not enough

Real patients frequently have coupled failures. Peritonitis can worsen ultrafiltration, appetite and glycemic control. Constipation can impair drainage, reduce delivered dialysis and increase discomfort, which then causes skipped therapy. Loss of RKF can expose a previously adequate prescription, leading to volume overload and higher glucose use, which increases metabolic burden. Frailty or cognitive decline can make otherwise minor technical problems recurrent. Multidomain failure is recognized when a single-domain intervention produces only partial or transient improvement.

Table 19.15 — Common coupled-failure patterns.

Pattern	Coupled domains	Integrated response
Peritonitis + low UF + poor appetite	Infection + membrane + nutrition	Treat infection; monitor delivery/volume; nutrition recovery plan
Constipation + alarms + low clearance	Mechanical + delivery + adequacy	Correct bowel issue first; then reassess delivered clearance
RKF decline + edema + high glucose exposure	Physiology + volume + metabolic	Recalculate total plan; redesign UF/sodium strategy
Frailty + contamination + caregiver burnout	Capability + infection risk + support	Assisted/retraining pathway; revisit goals
Obesity + hidden exit site + recurrent infection	Anatomy + access + infection	Exit-site/access strategy + infection source control
Repeated pain + shortened APD + fatigue	Mechanical/prescription + delivery + burden	Treat pain mechanism; simplify/retune therapy

MULTIDOMAIN RULE If one technically correct intervention repeatedly fails, ask what second domain is sustaining the problem.

15. From mechanism to prescription change: use the smallest effective lever

Figure 19.3 — Prescription levers. Time, fill volume, osmotic strategy, drain strategy, kidney/medication management and support should be changed only when they match the identified mechanism.

A good PD change is testable. It names the target mechanism, changes as few variables as possible, and predicts what should improve. Simultaneously increasing treatment time, glucose strength, cycle number and fill volume may produce a new number but destroys causal clarity and can increase burden or complications. Goal-directed care favors iterative, patient-centered adjustment rather than maximal prescription intensity. [1,7]

Table 19.16 — Problem → mechanism → smallest useful lever.

Problem	Mechanism	First targeted lever	Reassessment
Short-dwell fast transport with poor long-dwell UF	Dwell/transport mismatch	Redesign dwell/osmotic strategy	Volume symptoms + delivered UF
Drain pain terminating APD	Suction/tip/prescription mechanics	Drain/tidal/posture/mechanical correction	Pain + treatment completion
Congestion after RKF loss	Reduced total water/sodium removal	Rebuild total volume plan	Weight/BP/symptoms/urine
Low clearance from incomplete APD	Delivery failure due alarms	Fix drain cause	Completion + clearance
Metabolic burden from strong glucose	Excess osmotic exposure	Reduce unnecessary exposure after cause correction	Glycemia/weight + volume
Caregiver burnout	Support mismatch	Assisted/simplified workflow	Sustainability + treatment completion
Persistent catheter dysfunction	Structural access problem	Procedural salvage/revision	Functional inflow/outflow

ONE-CHANGE RULE When clinically safe, change one dominant lever at a time. If several changes are necessary because the patient is acutely unwell, document which endpoint each change is intended to affect.

16. Reassessment: close the loop or you have not troubleshot the problem

The timing of reassessment depends on severity and mechanism. A severe infection or respiratory problem requires immediate or same-day reassessment; a bowel-related drain problem may be reassessed after the corrective intervention; a prescription change may require several exchanges or days to judge; nutrition or support interventions may require longer. There is no single universal interval for every PD adjustment. The key requirement is that an endpoint is specified before the change is made.

Table 19.17 — Reassessment endpoints by domain.

Domain	What should improve	If it does not
Mechanical flow	Drain time, alarms, retained volume, pain	Image/procedural escalation
Volume	Symptoms, edema, weight trend, BP, net fluid balance	Re-localize intake/RKF/membrane/cardiac cause
Peritonitis	Clinical status + effluent inflammatory trajectory per guideline	Organism/source/refractory pathway
Catheter infection	Purulence/inflammation/tunnel findings	Source-control reassessment
Clearance	Delivered treatment + biochemical/symptom target	Validate collection, RKF, prescription again
Pain	Timing/intensity + treatment completion	Re-examine mechanical/infectious/abdominal causes
Metabolic	Glycemia, potassium, appetite, weight phenotype	Reassess exposure/intake/illness/medications
Support	Treatment completion, contamination, caregiver burden	Escalate assistance or modality planning

CLOSED-LOOP RULE An intervention without a planned reassessment is not troubleshooting; it is an experiment without an outcome measure.

17. When the problem does not resolve: escalation, HD transfer and quality improvement

Figure 19.4 — When troubleshooting becomes transition planning. Recurrent or multidomain problems require escalation and, when PD is no longer safe or sustainable, planned HD transfer or another pathway with clear causal documentation.

The 2026 ISPD position statement recommends replacing the imprecise terms “technique failure” and “technique survival” with direct reporting of HD transfer and other causes of loss from PD. For bedside troubleshooting, this changes the question from “Has PD failed?” to “What immediate event caused the transfer, what contributing factors were present, which were modifiable, and is return to PD feasible or desired?” The statement encourages programs to distinguish immediate from contributing causes because recurrent problems often reflect treatment burden, capability, access or program-level factors in addition to the final clinical event. [6]

Table 19.18 — Escalation and transition documentation.

Field	What to document
Immediate cause	The event that directly led to HD transfer or PD interruption
Contributing causes	Infection history, access problems, membrane dysfunction, frailty, treatment burden, caregiver/system factors
Reversibility	Temporary, potentially correctable, or unlikely to resolve
PD return potential	Whether PD restart is clinically feasible and aligned with patient goals
Intervention already attempted	Medical, prescription, retraining, access or surgical steps
Patient priorities	Preference, burden, life participation, risk tolerance
Transition plan	Temporary HD, permanent HD, transplant, conservative/supportive pathway or other
Program learning	What CQI action could prevent a similar avoidable transfer?

Quality improvement should use recurrent patterns rather than isolated anecdotes. Infection rates, access dysfunction, early HD transfer, repeated alarms, missed training competencies, hospitalization and treatment burden can reveal program-level failure modes. PDOPPS data show substantial international variation in time on PD and identify infection as a leading cause of HD transfer, supporting structured program review rather than attributing every transfer to patient-level factors. [9,10,12]

TRANSITION RULE A planned HD transfer can be the safest and most patient-centered outcome of excellent troubleshooting. The failure is not changing modality; the failure is allowing an unresolved problem to become an avoidable emergency.

18. Major clinical algorithms

Flowchart 19.1 — Any new PD problem. Stabilize first when needed, validate the problem, localize the dominant domain, treat the mechanism, and reassess.

Flowchart 19.2 — Low UF, weight gain or edema. Volume troubleshooting separates delivery/mechanics, systemic physiology, prescription mismatch and membrane dysfunction.

Flowchart 19.3 — Poor drain, slow flow or incomplete APD. Reversible extrinsic causes precede invasive access intervention.

Flowchart 19.4 — Pain, cloudy or abnormal effluent. Infection and surgical disease are safety-first branches; noninfectious mimics follow targeted assessment.

19. Retention tables: pattern recognition

Table 19.19 — If you see this, think this first.

Pattern	First thought	Do now
Low UF + drain alarms	Delivery/mechanical problem may masquerade as membrane failure	Check constipation, position, retained volume, event log
Low UF + good drainage + urine decline	Total water removal fell because RKF declined	Rebuild volume plan
Cloudy effluent	Peritonitis until assessed	Chapter 10 pathway
Red exit site without pus	Not automatically definitive ESI	Examine trend/trauma/dermatitis; Chapter 11 definitions
Purulent exit drainage	Definitive ESI phenotype	Culture/treat per Chapter 11
Dyspnea + right pleural effusion	Hydrothorax vs cardiac/other effusion	Chapter 12 evaluation
Repeated low clearance with short APD nights	Delivered-dose problem	Fix alarms/burden before dose escalation
High glucose use + weight/glycemia rise	Metabolic cost may be treating an unlocalized volume problem	Re-localize why UF is inadequate
Missed therapy + caregiver exhaustion	Support failure	Assisted/simplified plan; Chapter 16
Recurrent multidomain problems	PD sustainability question	Multidisciplinary review; transition planning if needed

Table 19.20 — High-yield “do not confuse” pairs.

Do not confuse	With	Correction
Prescribed PD	Delivered PD	Verify actual treatment
Low UF	Volume overload	Phenotype clinically
Low UF	Membrane failure	Exclude drainage/leak/RKF/prescription first
Alarm count	Catheter diagnosis	Use pattern + clinical mechanics
Cloudy effluent	Culture-positive infection only	Culture-negative peritonitis exists; mimics also exist
Erythema	Definitive exit-site infection	Purulence is central to definitive ESI definition
Low Kt/V	Global inadequate care	Use goal-directed assessment
High BP	Automatic need for stronger glucose	Confirm volume
Missing upload	Nonadherence	Check connectivity/data
HD transfer	“Technique failure”	Use neutral 2026 ISPD terminology + causal documentation

20. Clinical pearls

1. The fastest route to the right intervention is often to ask what changed first: the patient, the catheter, the prescription, the membrane, the kidney, or the support system.

2. If a problem is sudden, think delivery, access, infection or acute illness before chronic membrane failure.

3. If a problem is gradual, trend RKF, transport, nutrition, support and treatment burden rather than reacting to one datapoint.

4. Constipation is a dialysis complication when it causes catheter dysfunction, pain or inadequate delivery.

5. Low UF plus incomplete drainage is a mechanical problem until proved otherwise.

6. Cloudy effluent is a safety signal; diagnose first, theorize later.

7. “Adequate numbers” do not exclude inadequate life participation, nutrition, symptom control or volume management.

8. A repeated prescription change without a reassessment endpoint creates therapeutic noise.

9. When several domains are abnormal, correct the one with the highest safety consequence or causal leverage first.

10. Transition planning is part of PD excellence, not an admission of defeat.

21. Common pitfalls — and the correction

Table 19.21 — Pitfalls and corrections.

Pitfall	Why it fails	Correction
Increase dextrose whenever UF is low	Misses retained fluid, leak, constipation, RKF loss, sodium intake and membrane phenotype	Localize first
Increase dose whenever clearance is low	Collection/delivery error and RKF loss may be the real issue	Validate before prescribing
Treat every cycler alarm as machine trouble	Repeated drain alarms often encode catheter physiology	Read event pattern + assess mechanics
Treat every red exit site as infection	Overdiagnosis/antibiotic exposure	Use Chapter 11 definition
Treat every culture-negative cloudy bag as noninfectious	Culture-negative infectious peritonitis exists	Use Chapter 10 criteria and trajectory
Change several prescription variables together	Cannot tell what worked; increases burden	Use smallest effective lever
Ignore treatment burden because labs are acceptable	Delivered care may become unsustainable/unsafe	Assess capability, caregiver and goals
Keep retrying PD despite recurrent unresolved safety events	Turns planned transition into emergency HD	Escalate and plan
Call HD transfer “technique failure”	Imprecise and stigmatizing; obscures causes	Use 2026 ISPD HD-transfer terminology
Document only the final event	Misses modifiable contributing causes	Record immediate + contributing factors

22. Mini-cases: decisions, not trivia

Table 19.22 — Mini-cases.

Case	Clinical signal	Reasoning pause	Best next move
Case 1 — Low UF after a “bad week”	APD patient reports low UF, 2-kg weight gain and repeated drain alarms. Abdomen comfortable; urine unchanged.	The low UF may be retained volume from poor drainage, not membrane failure.	Review event log, constipation/posture and retained volume before increasing osmotic strength.
Case 2 — “Adequacy fell”	Stable patient has lower weekly clearance after an incomplete collection; symptoms and volume are unchanged.	Measurement validity comes before dose escalation.	Repeat/validate collection and delivered therapy; assess RKF trend.
Case 3 — Cloudy bag, minimal pain	Patient notices cloudy effluent but feels only mildly unwell.	Peritonitis can present without dramatic pain.	Immediate Chapter 10 diagnostic/treatment pathway.
Case 4 — High BP and no edema	Home BP is repeatedly high, weight stable, no orthopnea, strong UF.	Volume overload is not established.	Validate BP and assess medications/other causes before stronger dextrose.
Case 5 — Drain pain ends APD early	Patient terminates treatment 60–90 min early most nights because of late-drain pain.	“Nonadherence” is secondary to a prescription/mechanical symptom.	Treat drain pain/mechanics and redesign the APD drain strategy.
Case 6 — Frailty + contamination	Older patient has two contamination events after recent cognitive decline; daughter is exhausted.	Capability/support domain has changed.	Competency reassessment; assisted PD or transition plan rather than repeated blame/retraining alone.
Case 7 — Edema after urine loss	Previously stable CAPD patient loses residual urine over months and now needs stronger glucose.	The old prescription has been exposed by RKF loss.	Rebuild total sodium/water removal and formal membrane/prescription review.
Case 8 — Recurrent peritonitis + burden	After multiple infections the latest episode resolves, but patient no longer wishes to restart PD.	The immediate infection and treatment-burden context both matter.	Shared decision-making; document immediate/contributing causes and planned HD transfer per 2026 terminology.

23. Active recall

MUST MEMORIZE

Table 19.23 — Must-memorize troubleshooting anchors.

Prompt	Answer
First action in any PD problem?	Safety screen, then define the phenotype precisely.
Before interpreting a treatment metric?	Verify delivered therapy and measurement validity.
Six failure domains?	Delivery/data; access/mechanics; infection/inflammation; membrane/prescription; patient physiology; capability/support.
Low UF first principle?	It is a finding, not a diagnosis.
Poor drain first reversible cause to actively seek?	Constipation (also bladder/position/setup).
Cloudy effluent rule?	Peritonitis assessment takes priority.
Prescription-change principle?	Match one dominant lever to one identified mechanism when clinically safe.
What closes troubleshooting?	A predefined reassessment endpoint.
If one intervention repeatedly fails?	Look for a coupled second domain.
Preferred 2026 terminology for leaving PD to HD?	HD transfer, with immediate and contributing causes documented.

USE AS REFERENCE

Chapter 3 for PET and membrane transport classification.
Chapter 5 for catheter placement/function anatomy.
Chapter 8 for volume, sodium balance and UF failure.
Chapter 9 for CAPD/APD prescription optimization.
Chapter 10 for peritonitis diagnosis and treatment.
Chapter 11 for exit-site/tunnel infection definitions and source control.
Chapter 12 for flow dysfunction, leaks, hernias, hydrothorax and mechanical pain.
Chapter 13 for noninfectious abnormal effluent and metabolic complications.
Chapter 14 for long-term membrane failure and EPS.
Chapter 15 for nutrition/PEW.
Chapter 16 for frailty, assistance and difficult prescriptions.
Chapter 17 for hospitalized/urgent acute scenarios.
Chapter 18 for connected-cycler data and remote alert governance.

24. Flashcards: spaced repetition

Table 19.24 — Flashcards.

Question	Answer
Why is “low UF” not a diagnosis?	Because low net UF can arise from incomplete drainage, leak, intake/RKF change, prescription mismatch or membrane dysfunction.
What should precede interpretation of a cycler trend?	Verification that the treatment was actually delivered and the data are complete/credible.
Why can constipation mimic inadequate dialysis?	It can impair catheter drainage, shorten APD delivery and reduce effective exchanges.
What is the safest response to cloudy effluent?	Enter the peritonitis pathway promptly; consider noninfectious mimics only within a safe diagnostic process.
Why not change several prescription variables at once?	You lose causal clarity and may increase treatment burden or complications.
What does a low clearance result require before dose escalation?	Validation of collection, delivered therapy and residual kidney function.
What is the main distinction between hypertension and volume overload?	Hypertension is a sign with multiple causes; volume overload requires a volume phenotype.
When does treatment burden become a clinical mechanism?	When it causes incomplete treatment, contamination, early termination, caregiver collapse or goals conflict.
What should repeated correct but unsuccessful interventions trigger?	Search for a second coupled failure domain.
What does 2026 ISPD recommend instead of “technique failure”?	Describe HD transfer and record its immediate/contributing causes.
What is a good reassessment endpoint?	A patient- and mechanism-relevant change such as symptom relief, treatment completion, drain function, volume improvement or effluent trajectory.
What is the role of transition planning?	To prevent unresolved PD problems from becoming emergency modality changes.

25. Rapid differential / troubleshooting

Table 19.25 — One-minute problem sorter.

Presentation	First three questions	Primary route
Poor drain	Constipation? position? fibrin/blood?	Ch 5/12
Low UF	Delivered/drained? leak? RKF/intake changed?	Ch 8/12
Edema/weight gain	True fluid? urine decline? sodium/prescription?	Ch 8
High BP	Measurement valid? volume phenotype? meds/pain?	Ch 8/16
Low clearance	Collection valid? delivered therapy? RKF?	Ch 7/9
Abdominal pain	Fill/drain timing? cloudy fluid? focal/systemic?	Ch 10/12/13
Cloudy bag	Pain/systemic? cell/culture? mimic clues?	Ch 10/13
Red exit site	Pus? tunnel findings? trauma/dermatitis?	Ch 11
Hyperglycemia/weight gain	Glucose exposure? fluid vs calories? illness?	Ch 13/15
Missed/short therapy	Pain? alarms? cognition/support?	Ch 16/18
Hospital deterioration	What acute goal? is PD safe? what changed?	Ch 17
Repeated multidomain events	What is immediate cause? contributing causes? reversibility?	Integrated review / transition plan

TROUBLESHOOTING SHORTCUT If you are about to change the prescription but cannot say which domain and mechanism are failing, stop and collect the next discriminating piece of information.

26. Final revision sheet

CORE CONCEPT PD troubleshooting is a closed-loop diagnostic discipline: define the phenotype, exclude danger, verify delivery, localize the failing domain, name the mechanism, make the smallest useful change, and reassess.

One-minute revision

Safety before troubleshooting.
Delivered therapy before physiology.
Localization before prescription.
Mechanism before lever.
One dominant change when clinically safe.
Reassessment before declaring success.
Multidomain thinking when the problem recurs.
Treatment burden and support are clinical domains, not soft extras.
Planned escalation/procedure can preserve PD; planned HD transfer can also be the correct outcome.
Use neutral causal language: HD transfer, immediate cause, contributing causes, reversibility and learning.

TEN TAKE-HOME RULES

1. Never treat a number before validating how it was generated.

2. Low UF is a finding; membrane failure is one possible diagnosis.

3. Poor drainage can convert a technically adequate prescription into inadequate delivered therapy.

4. Cloudy effluent is a time-sensitive infection signal until properly assessed.

5. Redness alone is not the same as definitive exit-site infection.

6. Volume, clearance, pain and treatment burden must be interpreted as separate but interacting domains.

7. Prescription changes should be mechanism-linked and testable.

8. Recurrent problems often indicate a second uncorrected domain.

9. Treatment that cannot be safely delivered at home is not an adequate prescription, even if it looks ideal on paper.

10. A planned transition is safer than repeated unsuccessful rescue.

One-minute bedside synthesis

State the complaint in one line. Ask whether anyone is in danger. Confirm what treatment was actually delivered. Choose the dominant failure domain. Name the mechanism. Make the smallest safe correction. Decide what should improve and when you will check it. If it does not improve, do not simply intensify the same intervention—re-localize the problem or escalate the level of care.

FINAL MENTAL MODEL PD succeeds when six systems remain aligned: treatment is delivered, the catheter works, infection is controlled, the membrane/prescription match, the patient’s physiology is supported, and the home plan is sustainable. Troubleshooting is the process of finding which alignment has been lost.

Rapid oral viva

“The UF is low.” — What four non-membrane explanations must you exclude first?
“The cycler alarms every night.” — How do you separate machine/data failure from catheter mechanics?
“Kt/V fell.” — What makes the result valid enough to act on?
“The bag is cloudy.” — What is the safety-first pathway?
“BP is high.” — What evidence would make you treat volume rather than the number?
“The patient keeps missing exchanges.” — What capability/support questions come before blame?
“Three correct interventions have not solved the problem.” — What does multidomain failure mean?
“The patient is moving to HD.” — How should this be described and documented in 2026 terminology?

SAFETY BOUNDARY This chapter is a reasoning and routing framework. Disease-specific diagnostic criteria, drug doses, antimicrobial regimens, PET/UF thresholds, access procedures and urgent KRT decisions remain governed by their dedicated chapters, current guidelines, local protocols and direct clinical assessment.

27. Selected authoritative references

1. Brown EA, Blake PG, Boudville N, et al. International Society for Peritoneal Dialysis practice recommendations: Prescribing high-quality goal-directed peritoneal dialysis. Perit Dial Int. 2020;40(3):244–253. https://doi.org/10.1177/0896860819895364. PMID: 32063219.

2. Morelle J, Stachowska-Pietka J, Öberg C, et al. ISPD recommendations for the evaluation of peritoneal membrane dysfunction in adults: classification, measurement, interpretation and rationale for intervention. Perit Dial Int. 2021;41(4):352–372. https://doi.org/10.1177/0896860820982218. PMID: 33563110.

3. Li PKT, Chow KM, Cho Y, et al. ISPD peritonitis guideline recommendations: 2022 update on prevention and treatment. Perit Dial Int. 2022;42(2):110–153. https://doi.org/10.1177/08968608221080586. PMID: 35264029.

4. Chow KM, Li PKT, Cho Y, et al. ISPD Catheter-related Infection Recommendations: 2023 Update. Perit Dial Int. 2023;43(3):201–219. https://doi.org/10.1177/08968608231172740. PMID: 37232412.

5. Crabtree JH, Shrestha BM, Chow KM, et al. Creating and Maintaining Optimal Peritoneal Dialysis Access in the Adult Patient: 2019 Update. Perit Dial Int. 2019;39(5):414–436. https://doi.org/10.3747/pdi.2018.00232. PMID: 31028108.

6. Quinn RW, Johnson DW, Mehrotra R, et al. 2026 ISPD Position Statement on tracking and reporting loss from PD therapy. Perit Dial Int. Published online June 17, 2026. https://doi.org/10.1177/08968608261461639.

7. Borràs Sans M, Ponz Clemente E, Rodríguez Carmona A, et al. Clinical guideline on adequacy and prescription of peritoneal dialysis. Nefrologia (Engl Ed). 2024;44 Suppl 1:1–27. https://doi.org/10.1016/j.nefroe.2024.09.001. PMID: 39341764.

8. Hurst H, Figueiredo AE, Perez Moran D, et al. Peritoneal dialysis training and interventions: A narrative review. Perit Dial Int. 2026;46(1):6–15. https://doi.org/10.1177/08968608251328517. PMID: 40221963.

9. Lambie M, Zhao J, McCullough K, et al. Variation in Peritoneal Dialysis Time on Therapy by Country: Results from the Peritoneal Dialysis Outcomes and Practice Patterns Study. Clin J Am Soc Nephrol. 2022;17(6):861–871. https://doi.org/10.2215/CJN.16341221. PMID: 35641246.

10. Perl J, Fuller DS, Bieber BA, et al. Peritoneal Dialysis-Related Infection Rates and Outcomes: Results From the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS). Am J Kidney Dis. 2020;76(1):42–53. https://doi.org/10.1053/j.ajkd.2019.09.016. PMID: 31932094.

11. Nataatmadja M, Cho Y, Johnson DW. Continuous Quality Improvement Initiatives to Sustainably Reduce Peritoneal Dialysis-Related Infections in Australia and New Zealand. Perit Dial Int. 2016;36(5):472–477. https://doi.org/10.3747/pdi.2016.00114. PMID: 27659926.

12. Kraft L, Oppold J, Kitterer D, et al. Changing microbiology and outcomes of PD-associated peritonitis over four decades. Clin Kidney J. 2026;19(1):sfaf387. https://doi.org/10.1093/ckj/sfaf387. PMID: 41536568.

13. Blake PG, Bargman JM. Peritoneal dialysis. In: Brenner & Rector's The Kidney. 12th ed. Elsevier; 2024. Foundational physiology, prescription, adequacy and complication framework.

SOURCE NOTE Current ISPD guideline status and contemporary PD evidence were checked 3 September 2026. This synthesis intentionally avoids inventing new universal thresholds. When a troubleshooting branch reaches a disease-specific decision, the numerical criteria and treatment details in the relevant chapter, current guideline, product information and local protocol take precedence.

CHAPTER 19 COMPLETE

NEXT: CHAPTER 20 — FINAL REVIEW: ALGORITHMS, CASES, HIGH-YIELD TABLES AND MASTER REVISION