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CDR CSR Board Certified Specialist in Renal Nutrition

7.1 Formulating Valid PES Statements in Complex Dialysis Patients

Q: A maintenance hemodialysis patient presents with a pre-dialysis serum phosphorus of 8.2 mg/dL. He is currently prescribed sevelamer carbonate 1,600 mg three times daily with meals. During the nutrition interview, the patient states, 'I take my morning and evening pills faithfully at home, but I am embarrassed to pull out prescription bottles at work during lunch, and I regularly purchase fast-food deli sandwiches from the cafeteria.' Which of the following PES statements demonstrates valid diagnostic formulation according to standardized dietetic terminology and root-cause analysis?

Excessive mineral intake (phosphorus) related to omitted midday phosphate binder doses due to social embarrassment in the workplace and frequent consumption of convenience foods containing inorganic phosphate additives as evidenced by serum phosphorus of 8.2 mg/dL, patient self-report of omitting lunch binders, and dietary recall confirming inorganic additive exposure.. The statement selecting Excessive mineral intake (phosphorus) as the problem, linked to omitted midday binder doses due to workplace social embarrassment and inorganic additive intake, exemplifies an auditable, valid renal PES statement. The Problem is an established eNCPT intake label; the Etiology identifies specific behavioral and social root causes that the dietitian can directly solve (e.g., prescribing discrete pill containers, meal timing adjustments, binder powder, and teaching additive-free workplace food substitutions); and the Signs/Symptoms provide concrete, verifiable benchmarks. The choice identifying altered laboratory values related to end-stage renal disease is invalid because ESRD is an unchangeable medical diagnosis rather than a nutritional etiology amenable to dietetic care. The option citing knowledge deficit related to hyperphosphatemia confuses the clinical sign with the root cause and fails to address binder timing. Finally, the choice claiming non-adherence related to patient refusal employs judgmental, non-standardized terminology and misrepresents an addressable social barrier as willful defiance.

Q: A 56-year-old female with diabetic nephropathy on automated peritoneal dialysis (APD) presents for her monthly clinic visit. Her current prescription consists of four 2-liter 2.5% dextrose overnight cycler exchanges and a 7.5% icodextrin long daytime dwell. Over the past 3 months, her dry weight has increased by 4.2 kg (current BMI 33.5 kg/m²), her HbA1c has worsened from 7.4% to 9.2%, and her fasting blood glucose averages 210 mg/dL. Nutritional review estimates that she absorbs roughly 90–130 g of dextrose daily from her dialysate (about 300–440 kcal/day), yet her dietary meal plan has never been modified to compensate for this dialytic energy load. Which PES statement represents the most appropriate, valid diagnostic formulation?

Excessive energy intake related to uncompensated peritoneal glucose absorption from high-concentration dextrose dialysate without corresponding dietary caloric adjustment as evidenced by estimated dialysate dextrose absorption of about 90–130 g/day (300–440 kcal/day), a non-edematous weight gain of 4.2 kg over 90 days, and an HbA1c of 9.2%.. The diagnosis of Excessive energy intake related to uncompensated peritoneal glucose absorption without dietary adjustment directly identifies the physiological and nutritional root cause. In peritoneal dialysis, glucose absorption from dextrose dialysate can deliver hundreds of unmeasured kilocalories daily; failing to offset this in the oral meal plan drives severe weight gain and loss of glycemic control. The etiology is modifiable through coordinated dietary adjustment and collaboration with the nephrologist to evaluate dialysate dextrose strength. The statement citing inappropriate carbohydrate intake related to diabetes and PD is invalid because it uses medical diagnoses as etiologies. The statement focusing on altered laboratory values due to insulin failure addresses a physician pharmacotherapy issue rather than a primary nutritional diagnosis. Finally, attributing the 4.2 kg weight gain to sodium and hypervolemia ignores the quantified dialysate calorie load and the documented non-edematous weight gain.

Q: An outpatient renal dietitian is reviewing the clinical record of an 82-year-old maintenance hemodialysis patient with progressive protein-energy wasting, vascular dementia, and complete edentulism with poorly fitting dentures. The dietitian drafts the following partial PES statement: 'Inadequate oral intake (NI-2.1) related to impaired mastication secondary to ill-fitting dentures and impaired executive function for meal preparation secondary to vascular dementia...' Which of the following data sets provides the necessary, clinically valid signs and symptoms to complete this PES statement for an auditable medical record?

Documented unintentional dry weight loss of 8.5% over the past 90 days, normalized protein catabolic rate (nPCR) of 0.62 g/kg/day, serum albumin of 2.8 g/dL via bromocresol purple assay, and severe bilateral temporal muscle wasting on physical examination.. Valid Signs and Symptoms in a renal PES statement must be objective, quantifiable, and directly relevant to the Problem being diagnosed. For Inadequate oral intake and protein-energy wasting, documented dry weight loss of 8.5% over 90 days (exceeding the significant weight loss threshold), a sub-target nPCR of 0.62 g/kg/day (reflecting severely inadequate dietary protein intake), visceral protein depletion (albumin 2.8 g/dL via BCP), and objective muscle wasting on physical examination provide unambiguous, verifiable diagnostic criteria. Vague subjective statements regarding fatigue and cooking difficulties lack measurable parameters. Medical diagnoses and dialysis vintage describe baseline history rather than quantifiable nutritional signs. Finally, potassium, parathyroid hormone, and modest interdialytic weight gain are mineral and volume indices that do not substantiate inadequate oral energy or protein intake.

Key Takeaways

A valid renal PES statement requires an eNCPT standardized diagnostic label (Problem), a root cause amenable to nutrition intervention (Etiology), and quantifiable clinical or biochemical metrics that serve as auditable monitoring benchmarks (Signs and Symptoms).
Common etiology errors in nephrology practice include restating the medical diagnosis (e.g., 'related to end-stage renal disease') or blaming unmodifiable physiological states rather than isolating modifiable behavioral, educational, or access barriers.
In peritoneal dialysis, unmeasured dialysate dextrose absorption constitutes a substantial systemic carbohydrate and energy load (often roughly 300–800 kcal/day) that must be quantified and integrated into energy-related PES formulations.
Acute catabolic insults like peritonitis escalate daily dialytic effluent protein losses from a baseline of 5–15 g/day to >20–30 g/day, demanding an immediate diagnostic shift to Inadequate Protein-Energy Intake (NI-5.3) with intensified macronutrient goals.
Elderly hemodialysis patients with neurocognitive decline and dentition loss require multi-factorial root-cause analysis distinguishing physiological uremic hyporexia from mechanical and executive-function barriers to food intake.

Last updated: September 2026

Formulating Valid PES Statements in Complex Dialysis Patients

Core Clinical Principle: A clinically valid Nutrition Diagnostic (PES) statement in nephrology must identify a specific problem that the Registered Dietitian Nutritionist (RDN) can independently treat, mitigate, or resolve. Selecting an unmodifiable medical disease as the etiology (such as "related to ESRD") renders the PES statement invalid, as medical diagnoses cannot be resolved through nutrition intervention alone. The etiology must articulate the modifiable root cause driving the nutritional disturbance.

The Nutrition Care Process (NCP) established by the Academy of Nutrition and Dietetics provides the standardized framework for clinical reasoning across the nephrology continuum. In maintenance hemodialysis (HD) and peritoneal dialysis (PD), patients present with complex metabolic derangements, severe polypharmacy, and conflicting fluid and dietary restrictions. The ability to formulate precise, auditable Problem-Etiology-Signs/Symptoms (PES) statements distinguishes the Board Certified Specialist in Renal Nutrition (CSR) and supports the measurable, individualized plan of care required by the CMS Conditions for Coverage.

1. The Anatomy of a Flawless Renal PES Statement

A valid PES statement is a single structured sentence connecting three distinct components using standardized syntax:

$\text{Problem (Diagnostic Label)} \quad \xrightarrow{\text{related to (RT)}} \quad \text{Etiology (Root Cause)} \quad \xrightarrow{\text{as evidenced by (AEB)}} \quad \text{Signs \& Symptoms (Objective Data)}$

The Three Pillars

Problem ( $P$ ) — Standardized Diagnostic Label:
- Must be drawn directly from the standardized electronic Nutrition Care Process Terminology (eNCPT).
- Categorized into three primary domains: Intake ( $NI$ ), Clinical ( $NC$ ), and Behavioral-Environmental ( $NB$ ).
- In renal nutrition, the Intake domain is preferred whenever applicable (e.g., Excessive mineral intake [phosphorus], Inadequate protein-energy intake, Excessive energy intake) because intake problems are most directly responsive to targeted Medical Nutrition Therapy (MNT).
Etiology ( $E$ ) — The Actionable Root Cause:
- Preceded by the linking phrase "related to" (RT).
- Identifies the underlying physiological, behavioral, environmental, educational, or socioeconomic driver of the Problem.
- The Golden Rule of Renal Etiologies: Ask "Why?" at least three to five times until reaching the root factor that the dietitian's intervention will specifically target. For example, if a patient has hyperkalemia, the etiology is not "chronic kidney disease"; it is "daily consumption of high-potassium salt substitutes due to lack of prior education regarding dietary sources of potassium chloride."
Signs and Symptoms ( $S$ ) — Quantifiable Evidence & Monitoring Benchmarks:
- Preceded by the linking phrase "as evidenced by" (AEB).
- Combines objective clinical data (biochemical labs, anthropometrics, NFPE findings, dialytic adequacy kinetics) and validated subjective reports (diet recalls, appetite scores).
- The data points listed in Signs and Symptoms serve as the exact baseline parameters that the dietitian will re-evaluate during Nutrition Monitoring and Evaluation (the fourth step of the NCP).

2. Rules of Rigorous PES Formulation in Renal Practice

PES Element	Essential Clinical Criteria	Common Nephrology Pitfalls to Avoid
Problem ( $P$ )	• Selected from eNCPT terminology; Clear, specific, and concise; Reflects the primary nutritional diagnosis	• Blending multiple problems into one (e.g., "Hyperkalemia and malnutrition"); Using medical diagnoses as nutrition problems (e.g., "Uremia" or "Fluid overload" instead of Excessive fluid intake)
Etiology ( $E$ )	• Represents the true root cause; Amenable to dietetic intervention; Explains why the problem exists	• Restating the problem (e.g., "Excessive mineral intake RT high phosphorus levels"); Citing non-modifiable disease (e.g., "RT ESRD on hemodialysis"); Blaming factors the RDN cannot influence (e.g., "RT nephrologist prescription")
Signs/Symptoms ( $S$ )	• Objective, quantifiable, and verifiable; Directly proves the existence of the Problem; Provides measurable metrics to track over time	• Vague subjective statements (e.g., "AEB patient feels tired and eats poorly"); Including unrelated lab abnormalities (e.g., listing calcium in a protein deficiency diagnosis); Omitting numerical baselines (e.g., "AEB elevated potassium" instead of "AEB serum K 6.4 mEq/L")

3. Complex Clinical Scenarios & Valid PES Formulations

To master advanced diagnostic formulation, renal dietitians must analyze multi-morbid patient presentations across diverse renal replacement modalities.

Scenario 1: Maintenance Hemodialysis with Severe Hyperphosphatemia & Binder Pill Burden

Clinical Presentation: A 48-year-old male on in-center hemodialysis (vintage 3 years) presents with a pre-dialysis serum phosphorus of 8.4 mg/dL (target: 3.5–5.5 mg/dL). He is prescribed calcium acetate 667 mg, two capsules three times daily with meals (total 6 pills/day), alongside 11 other non-renal daily medications.
Dietary & Behavioral Assessment: Diet history reveals an estimated dietary phosphorus intake of 1,750 mg/day (45% derived from highly bioavailable inorganic phosphate additives in fast foods and commercial iced teas). The patient reports feeling overwhelmed by taking 17 pills daily and frequently forgets or chooses not to carry binder bottles when eating lunch at work.
Root Cause Analysis: The hyperphosphatemia is driven by two converging factors: an unmanageable binder pill burden leading to omitted midday doses, coupled with high consumption of inorganic phosphate food additives due to lack of label-reading literacy.
Valid PES Statement:

Excessive mineral intake (phosphorus) (NI-5.10.2) related to high phosphate binder pill burden resulting in omitted midday doses and frequent consumption of convenience foods containing inorganic phosphate additives as evidenced by serum phosphorus of 8.4 mg/dL, patient self-report of omitting lunch binder doses 5 days per week, and dietary recall confirming 1,750 mg/day phosphorus intake with widespread additive exposure.

Scenario 2: Diabetic Peritoneal Dialysis with Dialysate Dextrose Overload & Obesity

Clinical Presentation: A 54-year-old female with Diabetic Kidney Disease on Automated Peritoneal Dialysis (APD) presents for monthly clinic. Regimen: four 2-liter 2.5% dextrose overnight cycler exchanges plus one 2-liter 4.25% dextrose long daytime dwell. Over the past 90 days, she gained 4.5 kg of dry weight (BMI increased from 31.2 to 32.8 kg/m²). Her HbA1c climbed from 7.6% to 9.4%, and fasting blood glucoses average 215 mg/dL.
Kinetic Calculation: Short cycler dwells absorb a smaller share of the instilled dextrose (commonly estimated at about 40–50%) than long dwells (about 60–70%). Using 45% for the four cycler bags (4 × 2 L × 25 g/L = 200 g instilled) and 65% for the 4.25% day dwell (2 L × 42.5 g/L = 85 g instilled), her daily peritoneal dextrose absorption is: $\text{Daily Dextrose} = (200\,\text{g} \times 0.45) + (85\,\text{g} \times 0.65) = 90\,\text{g} + 55\,\text{g} = 145\,\text{g} \text{ monohydrate} \times 3.4\,\text{kcal/g} \approx 493\,\text{kcal/day}$ (Absorption varies with transport type and dwell length; high transporters absorb more.)
Dietary Assessment: Patient consumes an unadjusted 2,000 kcal/day oral diet with 50% carbohydrates, unaware that her dialysate provides substantial caloric and glucose loads.
Valid PES Statement:

Excessive energy intake (NI-1.3) related to uncompensated peritoneal dextrose absorption from hypertonic dialysate combined with lack of dietary carbohydrate and caloric adjustment as evidenced by estimated absorption of ~145 g dialytic dextrose (~493 kcal/day), 4.5 kg non-edematous weight gain over 3 months, HbA1c increase from 7.6% to 9.4%, and average fasting blood glucose of 215 mg/dL.

Scenario 3: Non-Dialysis CKD Stage 4 with Progressive Decline & High Protein Intake

Clinical Presentation: A 66-year-old male with CKD Stage G4A3 (eGFR 21 mL/min/1.73m², urine albumin-to-creatinine ratio [UACR] 1,100 mg/g) demonstrates rapid renal function decline from an eGFR of 28 mL/min/1.73m² 6 months prior. Serum urea nitrogen (BUN) is 58 mg/dL, serum creatinine 3.2 mg/dL.
Dietary Assessment: A 3-day food record and Maroni formula calculation from a 24-hour urine collection show a protein equivalent of total nitrogen appearance (PNA) of 1.45 g/kg/day, comprising large daily portions of red meat and poultry. The patient had received no prior renal MNT and believed high protein was necessary to combat chronic fatigue.
Root Cause Analysis: Patient lacks knowledge regarding the hemodynamic burden of glomerular hyperfiltration and nitrogenous waste generation driven by excessive dietary protein in advanced non-dialysis CKD.
Valid PES Statement:

Excessive protein intake (NI-5.7.2) related to food- and nutrition-related knowledge deficit regarding the nephroprotective role of moderate protein restriction in advanced CKD as evidenced by 24-hour urinary PNA of 1.45 g/kg/day (exceeding KDOQI target of 0.55–0.60 g/kg/day), 3-day food log confirming meat-heavy intake, and progressive eGFR decline from 28 to 21 mL/min/1.73m² over 6 months.

Scenario 4: Hospitalized Peritoneal Dialysis Patient with Acute Catabolic Peritonitis

Clinical Presentation: A 50-year-old male on Continuous Ambulatory Peritoneal Dialysis (CAPD) is admitted with bacterial peritonitis (Staphylococcus epidermidis). Peritoneal effluent is cloudy with an effluent white blood cell count of 3,800/μL (85% neutrophils). He presents with severe abdominal pain, nausea, and persistent fever.
Clinical Assessment: Systemic inflammation is marked (hs-CRP 54 mg/L). Normal daily peritoneal protein loss (5–15 g/day) has escalated to 26 g/day due to acute peritoneal membrane pore dilation and hyperpermeability. His oral intake has dropped to <800 kcal/day and 25 g protein/day due to severe uremic and inflammatory anorexia. Serum albumin plummeted from 3.8 g/dL to 2.5 g/dL (BCP assay) in 10 days.
Valid PES Statement:

Inadequate protein-energy intake (NI-5.3) related to acute systemic hypercatabolism, inflammatory anorexia, and massive peritoneal effluent protein clearance secondary to acute bacterial peritonitis as evidenced by daily peritoneal protein loss of 26 g/day, oral intake meeting <35% of estimated caloric and protein needs, and an acute serum albumin reduction from 3.8 to 2.5 g/dL over 10 days.

Scenario 5: Elderly Hemodialysis Patient with Vascular Dementia, Dentition Loss & PEW

Clinical Presentation: An 81-year-old female on in-center hemodialysis (vintage 5 years) displays progressive protein-energy wasting. Dry weight dropped 8.5% over the past 90 days (BMI 18.8 kg/m²). Pre-dialysis serum albumin is 2.8 g/dL (BCP assay), and normalized protein catabolic rate (nPCR) is 0.62 g/kg/day.
Clinical & Functional Assessment: Nutrition-Focused Physical Exam (NFPE) reveals severe bilateral temporal wasting, prominent clavicles, and hollow interosseous spaces. The patient lives alone with worsening vascular dementia, frequently forgets meals, has broken, ill-fitting dentures causing severe masticatory pain, and exhibits uremic dysgeusia.
Root Cause Analysis: Nutritional decline is driven by an inability to chew solid food combined with cognitive inability to organize food shopping and meal preparation.
Valid PES Statement:

Inadequate oral intake (NI-2.1) related to impaired masticatory efficiency secondary to ill-fitting dentures and impaired executive function for meal preparation secondary to vascular dementia as evidenced by unintentional 8.5% dry weight loss over 3 months, BMI of 18.8 kg/m², nPCR of 0.62 g/kg/day, serum albumin of 2.8 g/dL via BCP, and severe muscle wasting in temporal and clavicular regions on NFPE.

4. Audit Checklist for Renal Nutrition PES Statements

Before submitting a PES statement into an electronic health record (EHR) or dialysis Quality Assessment and Performance Improvement (QAPI) tracking system, verify it against the following audit rubric:

Problem: Is the diagnostic label an exact phrase from the current eNCPT terminology?
Etiology: Will the dietitian's planned intervention directly resolve or mitigate this etiology?
Etiology: Did I avoid using a medical diagnosis (e.g., ESRD, AKI, diabetes) as the root cause?
Signs/Symptoms: Are the metrics quantifiable, objective, and auditable (exact values, dates, percentages)?
Monitoring Concordance: Will re-measuring these exact signs and symptoms in 30–90 days prove whether my nutrition prescription succeeded?

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Nephrology PES Statement Formulation and Validation Algorithm

Test Your Knowledge

A maintenance hemodialysis patient presents with a pre-dialysis serum phosphorus of 8.2 mg/dL. He is currently prescribed sevelamer carbonate 1,600 mg three times daily with meals. During the nutrition interview, the patient states, 'I take my morning and evening pills faithfully at home, but I am embarrassed to pull out prescription bottles at work during lunch, and I regularly purchase fast-food deli sandwiches from the cafeteria.' Which of the following PES statements demonstrates valid diagnostic formulation according to standardized dietetic terminology and root-cause analysis?

Excessive mineral intake (phosphorus) related to omitted midday phosphate binder doses due to social embarrassment in the workplace and frequent consumption of convenience foods containing inorganic phosphate additives as evidenced by serum phosphorus of 8.2 mg/dL, patient self-report of omitting lunch binders, and dietary recall confirming inorganic additive exposure.

Altered nutrition-related laboratory values related to end-stage renal disease and loss of nephron phosphorus clearance as evidenced by serum phosphorus of 8.2 mg/dL and current sevelamer prescription.

Food- and nutrition-related knowledge deficit related to hyperphosphatemia as evidenced by purchasing fast-food deli sandwiches and an elevated serum phosphorus of 8.2 mg/dL.

Non-adherence to medical nutrition therapy related to patient refusal to take prescribed medications as evidenced by serum phosphorus of 8.2 mg/dL and missing lunch sevelamer doses.

Test Your Knowledge

A 56-year-old female with diabetic nephropathy on automated peritoneal dialysis (APD) presents for her monthly clinic visit. Her current prescription consists of four 2-liter 2.5% dextrose overnight cycler exchanges and a 7.5% icodextrin long daytime dwell. Over the past 3 months, her dry weight has increased by 4.2 kg (current BMI 33.5 kg/m²), her HbA1c has worsened from 7.4% to 9.2%, and her fasting blood glucose averages 210 mg/dL. Nutritional review estimates that she absorbs roughly 90–130 g of dextrose daily from her dialysate (about 300–440 kcal/day), yet her dietary meal plan has never been modified to compensate for this dialytic energy load. Which PES statement represents the most appropriate, valid diagnostic formulation?

Inappropriate intake of carbohydrates related to diabetes mellitus and automated peritoneal dialysis as evidenced by elevated HbA1c of 9.2% and BMI of 33.5 kg/m².

Excessive energy intake related to uncompensated peritoneal glucose absorption from high-concentration dextrose dialysate without corresponding dietary caloric adjustment as evidenced by estimated dialysate dextrose absorption of about 90–130 g/day (300–440 kcal/day), a non-edematous weight gain of 4.2 kg over 90 days, and an HbA1c of 9.2%.

Altered nutrition-related laboratory values related to failure of outpatient insulin management as evidenced by fasting blood glucose of 210 mg/dL and HbA1c of 9.2%.

Excessive mineral intake (sodium) related to hypervolemia in peritoneal dialysis as evidenced by a 4.2 kg weight gain and automated cycler dwell times.

Test Your Knowledge

An outpatient renal dietitian is reviewing the clinical record of an 82-year-old maintenance hemodialysis patient with progressive protein-energy wasting, vascular dementia, and complete edentulism with poorly fitting dentures. The dietitian drafts the following partial PES statement: 'Inadequate oral intake (NI-2.1) related to impaired mastication secondary to ill-fitting dentures and impaired executive function for meal preparation secondary to vascular dementia...' Which of the following data sets provides the necessary, clinically valid signs and symptoms to complete this PES statement for an auditable medical record?

Patient reports feeling fatigued during dialysis treatments, spouse states that cooking is difficult, and the dialysis nurse notes sluggishness during fistula cannulation.

Confirmed diagnosis of end-stage renal disease, hemodialysis vintage of 5 years, and documented history of multi-infarct vascular dementia in neurological consultation notes.

Documented unintentional dry weight loss of 8.5% over the past 90 days, normalized protein catabolic rate (nPCR) of 0.62 g/kg/day, serum albumin of 2.8 g/dL via bromocresol purple assay, and severe bilateral temporal muscle wasting on physical examination.

Pre-dialysis serum potassium of 5.1 mEq/L, intact parathyroid hormone of 380 pg/mL, and an average interdialytic weight gain of 1.1 kg between weekly treatments.

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