Step 1: Assess

Gathering Data for an Assessment

Before asking the patient questions for your assessment, make sure to introduce yourself and set the agenda for the discussion. When gathering data for your assessment make sure to collect information on the patient’s:

  • Clinical Data
  • Anthropometric Data
  • Biochemical Data
  • Dietary Data and Social History

Case Study: Meet Raymond

Raymond Zetner, our case study patient. Raymond wears glasses and gives a closed-mouth smile as he sits by his bed in the hospital.
Raymond Zetner, your patient

In the case study for this section, you are a Registered Dietitian in cardiology in-patient unit. The patient you are assessing is Raymond Zetner, a 72 year old man with chronic kidney disease (CKD). Raymond was admitted to the cardiology in-patient unit with congestive heart failure. He currently has stage 4 CKD, secondary to hypertension, and is experiencing ankle edema.  He does not require dialysis at this time.

He has not yet been discharged from the hospital, and needs education before leaving.

Clinical Data

When gathering clinical data, consider:

  • Chronic Kidney Disease (CKD): What stage? What is the cause?
  • Dialysis prescription: Are they on dialysis? If so, what type and what prescription?
  • Comorbidities: Ex. Diabetes, hypertension, cardiovascular disease, hyperlipidemia, metabolic syndrome
  • Fluid Status: How much urine are they producing? Are they retaining fluid? Edema present?
  • GI symptoms: Constipation, nausea, vomiting, poor appetite, meat aversion, taste changes are common symptoms of in advanced CKD.
  • Medications: Replavite (Vit C & B complex, if on dialysis), Phosphate Binders (Tums/Calcium Carbonate, Sevelamer, Lanthanum), Calcitriol (Active Vitamin D), Iron

Raymond’s Clinical Data

  • CKD: Stage 4 CKD, secondary to hypertension
  • Dialysis prescription: Does not yet require dialysis
  • Comorbidities: Hypertension; patient admitted to hospital with congestive heart failure
  • Fluid Status: Ankle edema present
  • Medications: Lasix 40 mg , Ramipril 20 mg OD, Vitamin D 1000 IU OD, Omega-3 250 mg OD

Anthropometric Data

When gathering anthropometric data, you may retrieve this information from a variety of sources including the patient or their family members, the patient’s chart or admission docket, or other healthcare professionals on the interdisciplinary team. Here you will want:

  • Body weight
  • Weight history: Usual body weight
  • Dry weight /target weight / goal weight: Weight without any excess fluid, if on dialysis (edema-free body weight)
  • Inter-dialytic weight gains (if on hemodialysis): Fluid weight gained between dialysis sessions; this should be no more than 5% of body weight
  • Height
  • BMI

Raymond’s Anthropometric Data

  • Weight = 65 kg
  • Weight Hx = 62 kg (usual body weight)
  • Height = 162 cm
  • BMI = 24.7 kg/m2
  • SGA = A

Biochemical Data

You also want to gather the following labs included in the table below as part of your biochemical data. Keep in mind that the target ranges for patients with chronic kidney disease and those at end-stage renal disease may be different from the target ranges for the healthy population. Additionally, due lack of consensus and evidence surrounding certain labs values, such as phosphorus and A1C, target ranges may vary based on the physician.

Blood Work CKD target range ESRD target range If high, think: If low, think:
Creatinine No target

Will be elevated (>110 mmol/L)

No target

Will be elevated (>110 mmol/L)

Kidney failure Residual kidney function, overhydration
BUN / Urea 2.5-8.0 mmol/L

Usually elevated (>8 mmol/L)

15-30 mmol/L Kidney Disease, poor dialysis clearance, high protein intake Residual kidney function, frequent dialysis, low protein intake
Potassium 3.5-5.0 mmol/L 3.5-5.5 mmol/L Intake of high potassium foods, K supplementation, K bath, K-sparing medications (ACE inhibitor or ARB) Low intake, vomiting/diarrhea
Phosphorus 0.8-1.49 mmol/L 1.2-1.8 mmol/L Intake of high phosphorus foods, inadequate or not taking phosphate binders, high PTH, too much activated vitamin D Low intake, excessive phosphate binders
Calcium 2.1-2.6 mmol/L 2.1-2.6 mmol/L Meds (activated vitamin D, Calcium-based phosphate binders) Poor nutritional status, over hydration
Albumin 35-50 g/L >40 g/L Well-nourished / dehydration Infection / illness / poor nutritional status / overhydration
A1c <7.0 % 7.1-8.5% Uncontrolled diabetes Hypoglycemia
Hemoglobin 100-120 g/L 100-120 g/L High Erythropoietin stimulating agent (ESA) dose High Erythropoietin stimulating agent (ESA) dose, Iron deficiency, GI Bleed/blood loss
PTH 3-12 pmol/L 14-65 pmol/L Hyperparathyroidism Adynamic bone disease
Sodium 135-145 mmol/L 135-145 mmol/L Dehydration, poor intake Overhydration
Bicarbonate 23-31 mmol/L 23-31 mmol/L Alkalosis Metabolic acidosis, high protein intake

Interpreting Glomerular Filtration Rate

This table contains information that allows you to interpret a patient’s Glomerular Filtration Rate (GFR), which estimates the percentage at which their kidney is functioning. Based on their stage of kidney disease, this table also describes what types of actions would be reasonable and the dietary implications.

Stage Kidney Function (KF) GFR Action Effect on Diet
N/A At increased risk >90 with CKD risk factors Screening, CKD reduction Usually no effect on potassium (K) or phosphate (PO4). Sodium restriction, Avoid high protein intake >1.3 g/kg/day
I Kidney damage with normal or ↑ GFR >90 Diagnosis and treatment of underlying condition, delay progression Usually no effect on K/PO4. Sodium restriction, Avoid high protein intake >1.3 g/kg/day
II Mild ↓ KF 60-89 Estimating progression, delay progression Usually no effect on K/PO4. Sodium restriction, Avoid high protein intake >1.3 g/kg/day
III Moderate ↓ KF 30-59 Evaluating and treating complications, delay progression May have effect on K/PO4. Sodium restriction, Avoid high protein intake >1.3 g/kg/day
IV Severely ↓ KF 15-29 Preparing for kidney replacement therapy, treat complications, delay progression Likely some effect on K/PO4. Sodium restriction, Avoid high protein intake >1.3 g/kg/day
V Kidney Failure (End Stage Renal Disease – ESRD) < 15 or dialysis Renal replacement therapy (dialysis/transplant) if uremia is present Likely some effect on K/PO4. Sodium and fluid restriction. High protein diet required.


Raymond’s Biochemical Data

Here are the labs for Raymond which show that he has severely decreased renal function but does not yet require dialysis. Determine which lab values are WNL or are elevated. This information will be used when developing the nutrition care plan in the next section.

Lab Test Lab Result **Add units** Target Range
K 4.7 3.5 – 5.0
PO4 1.55 0.8 – 1.45
Ca 2.4 2.1 – 2.6
Creat 662
GFR 17
Urea 39 2.5 – 8.0
Alb 43 35 – 50
Na 129 135 – 145

Dietary Data and Social History

When gathering dietary and social history data, consider:

  • Current Diet
    • Diet order for inpatients
    • How much are they eating and drinking?
    • How is their appetite?
  • Diet Hx
    • , 24 hour recall, 3-day food record (Note: A food frequency questionnaire might be useful if trying to determine a specific dietary cause of a high serum potassium or phosphorus)
    • Details on protein intake and fluid intake
  • Eating behaviours at home
    • How many meals per day?
    • Frequency of eating out?
  • Factors affecting intake
    • Social History: do they have a support system? Housing? Income?
    • Food access and preparation: who does cooking and grocery shopping?

Raymond’s Dietary Data

  • Current Diet
    • Regular diet order
    • Fluid intake ~ 2 litres per day
    • Pt reports good appetite in hospital
  • Eating behaviours at home
    • Good appetite, eats 3 meals per day
    • Largest meal is dinner
  • Factors affecting intake
    • Lives alone
    • Full-time job as a lawyer
    • Eats out often
  • Diet recall of typical day prior to admission:
    • Breakfast: 3 eggs, 2 slices bacon, 2 whole wheat toast and 1 double double coffee
    • Lunch: 12 inch assorted meat submarine w/ lettuce, tomato, olives, cheese, mayo and 1 large cola
    • Dinner: Chicken breast (8 ounces), frozen french fries, peas and carrots and 1 can of cola

PART 1: ASSESS COMPLETE. Pause to think about the assessment strategies discussed and data collected. When you’re ready, move on to Part 2: Plan.



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Preparation for Dietetic Practice Copyright © by Megan Omstead, RD, MPH is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.