5.1

Summary

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SPECIMEN COLLECTION AND EVALUATION

For Specimen Evaluation, the patient should be instructed to collect a midstream clean catch urine sample of at least 10 mL.
The most concentrated and ideal sample for Routine Urinalysis is the first morning voided urine.
For Bacteriologic Examination, the preferred methods are catheterized specimen or suprapubic aspiration.
Timed Urine (12- or 24-hour) is required for quantitative measurements of urine components.
Specimen Labeling is a critical step; a lack of labels is considered a "mortal sin" in clinical microscopy.
Regarding Specimen Processing Time, the urine sample should be read within 30 minutes to 1 hour; specimens older than 1 hour without refrigeration must be discarded.
In Specimen Evaluation, refrigeration prevents cell lysis but has the drawback of increasing the precipitation of various substances.

PHYSICAL AND GROSS EXAMINATION

The Urochrome pigment is primarily responsible for the characteristic yellow color of urine.
Contributing Pigments to urine color include urobilin, uroerythrin, and mesobilifuscin (a byproduct of heme synthesis).
In Diabetes Mellitus, urine color may be surprisingly pale despite having a high specific gravity.
Colorless Urine is typically associated with Polyuria or Diabetes Insipidus.
In the context of Urine Clarity, Phosphate, ammonium urate, and carbonate precipitates will redissolve with the addition of acetic acid.
For Uric acid and urates causing Turbidity, the precipitates will redissolve upon warming the specimen to 60°C.
A uniform opalescence in Urine Clarity is typically indicative of a bacterial infection.
The presence of fecal material in a Gross Examination may suggest a fistulous connection.
In Acute Tubular Necrosis (ATN), a notable physical finding is a complete lack of urine odor.
Regarding Urine Volume, Polyuria is defined as an output exceeding 2000 mL per 24 hours.
Oliguria is defined as a urine volume less than 500 mL per 24 hours.
Specific Gravity measures the relative proportions of dissolved solid components (density) to the total volume.
The main contributors to Urinary Specific Gravity are Urea (20%) and Sodium Chloride (25%).
Isosthenuria occurs when the specific gravity is fixed at 1.010, signifying severe renal damage.
Hyposthenuria is defined as a specific gravity less than 1.007, commonly seen in Diabetes Insipidus.

METABOLIC DISORDERS AND URINE ODOR

Ketoacidosis is associated with a sweet, fruity urine odor.
Maple Syrup Urine Disease (MSUD) results in urine that smells like maple syrup.
Phenylketonuria (PKU) is characterized by a mousy or musty urine odor.
Tyrosinemia produces a rancid urine odor.
Isovaleric Acidemia and Glutaric Acidemia result in urine smelling like sweaty feet.
Cystinuria is associated with a rotten egg urine odor.
Trimethylaminuria results in an odor of rotting fish.
Methionine Malabsorption causes urine to smell like cabbage or hops.
Hawkinsinuria is associated with a swimming pool (chlorine) odor.

CHEMICAL SCREENING (REAGENT STRIPS)

Reagent Strips are the primary method used for the chemical examination of urine; they typically contain 10 parameters.
The Principle of Specific Gravity on a reagent strip is the pKa change of pretreated polyelectrolytes (an indirect method).
For Chemical Screening, Vitamin C (Ascorbic acid) can lead to false-negative glucose results.
In Chemical Screening, ignoring the specific reading times (e.g., 30 sec, 60 sec) for different parameters may result in false positives or negatives.
For Reagent Strip Methodology, "splitting" or cutting strips into two to save supplies is highly discouraged as it affects result accuracy.

MICROSCOPIC EXAMINATION: CELLS

As part of Microscopic Evaluation, cells and casts begin to lyse within 2 hours of collection.
Erythrocytes (RBCs) in normal urine are 0–3 per HPF; they appear as pale biconcave disks of ~7 µm.
Shadow Cells (Ghost Cells) are erythrocytes in non-fresh specimens where the hemoglobin has dissolved out.
For Microscopic Urinalysis, finding more than 3 RBCs/HPF is considered abnormal and can be caused by glomerulonephritis, stones, or trauma.
Dysmorphic RBCs must be differentiated from yeast and oil droplets; yeast cells show budding, while oil droplets are highly refractile.
Leukocytes (WBCs) in normal urine are 0–5 per HPF, and are usually neutrophils.
In Pyuria, finding >30 neutrophils/HPF with repeated sterile cultures is suggestive of tuberculosis or nephritis.
Squamous Epithelial Cells are the most frequent cells seen in normal urine but are of least clinical significance.
A high volume of Squamous Epithelial Cells in females usually indicates improper collection (contamination).
Transitional Epithelial Cells are round or pear-shaped with a centrally located nucleus; they are pathologic if found in clumps or sheets sans instrumentation.
The presence of increased Renal Tubular Epithelial Cells indicates tubular damage.

MICROSCOPIC EXAMINATION: CASTS AND CRYSTALS

Casts originate exclusively from the kidney (specifically the renal tubules).
Tamm-Horsfall Protein is the specific glycoprotein that forms the matrix of all urinary casts.
Cylindruria refers to the presence of casts in the urine sediment.
Hyaline Casts appear clear and transparent because they have no cells attached to the protein matrix yet.
Urinary pH is the most important factor and main determinant in identifying which crystal will precipitate.
Ammonium Biurate Crystals are known as "thorny apples" and appear only in alkaline urine.
Triple Phosphate (Struvite) Crystals are characterized by a "coffin lid" appearance.
Calcium Oxalate Monohydrate crystals typically present in a dumbbell shape.
Cystine Crystals are hexagonal plates found in acidic pH.
Cholesterol Crystals appear in the urine as angular or rhomboid shapes with notched corners.
Polarized Light Microscopy is the ideal method for properly examining and identifying crystals.

OTHER MICROSCOPIC FINDINGS

Herpes Simplex Virus infections can present with syncytial giant cells and eosinophilic intranuclear inclusions in urine.
Cytomegalovirus (CMV) produces basophilic intranuclear inclusions (owl-eye appearance).
Polyomavirus creates dense basophilic inclusions that completely fill the nucleus (decoy cells).
Fungi found in urine are most commonly Candida albicans.
Parasites commonly found in urine include Trichomonas vaginalis, Schistosoma haematobium, and Entamoeba histolytica.

REPORTING STANDARDS

In Urinalysis Reporting, the following are reported per Low Power Field (LPF): Casts and Abnormal Crystals ("Cast CrAbs").
In Urinalysis Reporting, the following are reported per High Power Field (HPF): Transitional Epithelia, Trichomonas, Bacteria, Yeast, and Normal Crystals ("TTBaYN").
For Quantitative Cells (RBCs, WBCs, Renal Epithelia), results are reported as a Range per HPF ("RaRe").

CONFUSING ENTITIES COMPARED
1. Diabetes Insipidus presents with colorless urine and low SG (<1.007), whereas Diabetes Mellitus may have pale urine but a high SG due to dissolved glucose.
2. Amorphous Phosphates cause turbidity in alkaline urine and dissolve in acetic acid, while Amorphous Urates cause turbidity in acidic urine and dissolve with heat (60°C).
3. RBCs in fresh urine appear as biconcave disks, but in non-fresh or dilute urine, they become Shadow Cells lacking hemoglobin.
4. Yeast cells can be mistaken for RBCs but are distinguished by budding and their resistance to acetic acid (which lyses RBCs).
5. Squamous Epithelial Cells are larger and flatter with small nuclei (insignificant), while Renal Tubular Epithelial Cells are smaller, rounder, and indicate tubular necrosis.
6. Isosthenuria is a fixed SG of 1.010 indicating loss of renal concentrating ability, while Hyposthenuria is a SG <1.007.
7. Triple Phosphate crystals look like "coffin lids" and appear in alkaline pH, whereas Calcium Oxalate (dihydrate) looks like "envelopes" and can appear in any pH (usually acid/neutral).
8. Ammonium Biurate are "thorny apples" found in alkaline urine, but Uric Acid crystals (varied shapes) are typical of acidic urine.
9. Polyuria is a volume >2000 mL/24hr, while Nocturia is specifically excess urine at night (>500 mL) with a low SG.
10. Hyaline Casts are colorless and composed only of Tamm-Horsfall protein, whereas Cellular Casts contain trapped RBCs, WBCs, or epithelial cells within the matrix.
11. Transitional Epithelial Cells have a central nucleus and "umbrella" shape, unlike Squamous Cells which have a small, centralized nucleus but a massive cytoplasm-to-nucleus ratio.
12. Sterile Pyuria (high WBCs but negative culture) is a hallmark for Renal Tuberculosis or nephritis.
13. Refractometer uses the refractive index (indirect) to measure SG, whereas the Urinometer is a hydrometer (direct) requiring large volumes of urine.
14. Reagent Strip SG uses pKa change (indirect) and is not affected by high molecular weight substances like radiopaque dye, unlike the refractometer.
15. Cystine Crystals are hexagonal and signify a metabolic error, whereas Uric Acid can occasionally be hexagonal but is strongly birefringent under polarized light.
16. Brightfield Microscopy is standard for general use, but Polarized Microscopy is required specifically for crystals and lipids.
17. Herpes inclusions are eosinophilic, while CMV and Polyomavirus inclusions are typically basophilic.
18. Oliguria is low output (<500 mL/day), whereas Anuria is the near-complete suppression of urine formation.
19. Urobilinogen and Bilirubin on dipsticks are often negative in normal urine; their presence usually indicates liver disease or hemolysis.
20. Calcium Oxalate Monohydrate is dumbbell-shaped, while the Dihydrate form is envelope-shaped.

QA

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What is the normal daily Urine Volume for an adult? | 600–1200 mL/day
What is the normal Nighttime Urine Volume limit? | <400 mL
Define Polyuria based on 24-hour output volume. | >2000 mL
Define Oliguria based on 24-hour output volume. | <500 mL
What is the volume and Specific Gravity (SG) finding in Nocturia? | >500 mL at night
Associated with low SG.
What is the normal range for Urinary Specific Gravity (SG)? | 1.016 – 1.022
(Normal up to 1.035)
Define Isosthenuria and state its clinical significance. | Fixed at 1.010
Signifies severe renal damage.
Define Hyposthenuria and name a related condition. | SG <1.007
Commonly seen in Diabetes Insipidus.
Describe the urine profile in Diabetes Mellitus regarding color and SG. | Pale but high SG
Due to dissolved glucose.
Which pigment is primarily responsible for the Urine Color (yellow)? | Urochrome
What does Dark Yellow or Amber Urine typically indicate? | Dehydration
In what conditions is Colorless Urine classically seen? (2) | 1) Polyuria
2) Diabetes Insipidus
What substances cause Turbid Urine Clarity? (4) | Salts, cells, bacteria, or fat
How do Amorphous Urates redissolve in urine? | Warming to 60°C
What is the standard Urine Odor? | Ammoniacal
A complete lack of odor in Gross Examination suggests: | Acute Tubular Necrosis
What is the normal range for RBCs per high power field? | 0–3 /hpf
What does finding >3 RBCs /hpf clinically signify? | Abnormal
Indicative of stones, trauma, etc.
What are Shadow Cells? | RBCs (Ghost cells)
Found in non-fresh specimens.
What is the normal findings for WBCs per high power field? | 0–5 /hpf
What clinical significance is attached to >5 WBCs /hpf? | Infection or Inflammation
Which leukocyte WBC type is predominantly found in urine? | Neutrophils
Find >30 neutrophils/HPF with a Sterile Culture indicates: | Tuberculosis or nephritis
Which Epithelial Cells are most frequent but least significant? | Squamous Epithelial Cells
What do Renal Tubular Epithelial Cells signify when increased? | Tubular damage
Describe the shape of Transitional Epithelial Cells. | Pear-shaped
Has a centrally located nucleus.
What are the only Casts found rare/few in normal urine? | Hyaline Casts
What is the term for a significant presence of Casts? | Cylindruria
Where do Casts exclusively originate? | Kidney (Renal tubules)
What specific glycoprotein forms the Cast Matrix? | Tamm-Horsfall Protein
What are Crystals dependent on for formation? | pH
Provide an example of Abnormal Crystals. | Cystine
For Specimen Evaluation, what instructions are given for volume? | Midstream clean catch
At least 10 mL.
What is the ideal sample for Routine Urinalysis? | First morning voided urine
Most concentrated.
Name the preferred methods for Bacteriologic Examination. (2) | 1) Catheterized specimen
2) Suprapubic aspiration
What is the requirement for Timed Urine (12- or 24-hour)? | Quantitative measurements
What is a "mortal sin" in Clinical Microscopy? | Lack of labels
What is the standard Specimen Processing Time? | Within 30 min to 1 hour
What is a drawback of Refrigeration in specimen evaluation? | Increases substance precipitation
List 3 Contributing Pigments to urine color. | 1) Urobilin
2) Uroerythrin
3) Mesobilifuscin
What is Mesobilifuscin a byproduct of? | Heme synthesis
For Urine Clarity, which precipitates dissolve in acetic acid? (3) | 1) Phosphate
2) Ammonium urate
3) Carbonate
What does Uniform Opalescence in urine clarity indicate? | Bacterial infection
Presence of Fecal Material in urine indicates: | Fistulous connection
Define Specific Gravity measurement focus. | Relative proportions of dissolved solids
Density of total volume.
Name the Main Contributors to urine SG. (2) | 1) Urea (20%)
2) Sodium Chloride (25%)
What urine odor is seen in Ketoacidosis? | Sweet, fruity
What urine odor is seen in Maple Syrup Urine Disease (MSUD)? | Maple syrup
What urine odor is seen in Phenylketonuria (PKU)? | Mousy or musty
What urine odor is seen in Tyrosinemia? | Rancid
What urine odors are seen in Isovaleric/Glutaric Acidemia? | Sweaty feet
What urine odor is seen in Cystinuria? | Rotten egg
What urine odor is seen in Trimethylaminuria? | Rotting fish
What urine odor is seen in Methionine Malabsorption? | Cabbage or hops
What urine odor is seen in Hawkinsinuria? | Swimming pool (chlorine)
What is the primary method for urine Chemical Screening? | Reagent Strips (10 parameters)
What is the Principle of Specific Gravity on a dipstick? | pKa change
Pretreated polyelectrolytes.
Which substance causes False-Negative Glucose results? | Vitamin C (Ascorbic acid)
Why is "splitting" Reagent Strips discouraged? | It affects result accuracy.
When do cells and casts begin to lyse in Microscopic Evaluation? | Within 2 hours
Describe the appearance of Erythrocytes (RBCs). | Pale biconcave disks
~7 µm diameter.
How do Yeast Cells differ from RBCs? (2) | 1) Show budding
2) Resist acetic acid.
Describe Oil Droplets in microscopic evaluation. | Highly refractile
What is the Significance of Dysmorphic RBCs? | Glomerular bleeding
What does a high volume of Squamous Epithelia in females indicate? | Improper collection (contamination)
When are Transitional Epithelial Cells pathologic? | Clumps or sheets
Occurring without instrumentation.
Why are Hyaline Casts clear/transparent? | No cells attached
Protein matrix only.
What is the nickname for Ammonium Biurate crystals? | "Thorny apples"
Ammonium Biurate crystals appear in which pH? | Alkaline urine
Describe Triple Phosphate (Struvite) appearance. | "Coffin lid"
Describe Calcium Oxalate Monohydrate shape. | Dumbbell shape
Describe Cystine Crystals appearance. | Hexagonal plates
Found in acidic pH.
Describe Cholesterol Crystals appearance. | Angular or rhomboid
Notched corners.
What is the ideal microscopy for Crystals identification? | Polarized Light Microscopy
Viruses (Inclusions): Herpes Simplex Virus | Eosinophilic intranuclear inclusions
Syncytial giant cells.
Viruses (Inclusions): Cytomegalovirus (CMV) | Basophilic intranuclear inclusions
"Owl-eye" appearance.
Viruses (Inclusions): Polyomavirus | Decoy cells
Completely fill the nucleus.
What is the most common Fungi in urine? | Candida albicans
List common urine Parasites. (3) | Trichomonas vaginalis,
Schistosoma haematobium,
Entamoeba histolytica.
Urinalysis Reporting: Reported per LPF? (2) | 1) Casts
2) Abnormal Crystals ("Cast CrAbs")
Urinalysis Reporting: Reported per HPF? (5) | Transitional Epithelia, Trichomonas,
Bacteria, Yeast, Normal Crystals ("TTBaYN").
how are Quantitative Cells (RBCs/WBCs) reported? | Range per HPF ("RaRe")
Compare DI vs DM regarding Specific Gravity. | DI: SG <1.007
DM: High SG.
Compare Amorphous Phosphates vs Urates (pH). | Phosphates: Alkaline
Urates: Acidic.
How do you distinguish Yeast vs RBCs chemically? | Acetic acid
(Lyses RBCs, yeast remains).
Compare Squamous vs Renal Tubular significance. | Squamous: Insignificant
Renal Tubular: Tubular damage/necrosis.
Compare Isosthenuria vs Hyposthenuria (SG). | Isosthenuria: 1.010
Hyposthenuria: <1.007.
Compare Triple Phosphate vs Calcium Oxalate shape. | Triple Phosphate: Coffin lids
Calcium Oxalate: Envelopes.
Describe Uric Acid crystals in acidic urine. | Varied shapes
Strongly birefringent.
Contrast Polyuria vs Nocturia volume. | Polyuria: >2000 mL/24hr
Nocturia: >500 mL at night.
Contrast Hyaline vs Cellular Casts content. | Hyaline: Protein matrix only
Cellular: Contains RBCs/WBCs/Epithelia.
Describe Transitional Epithelia nucleus position. | Central nucleus
"Umbrella" shape.
What is Sterile Pyuria a hallmark for? | Renal Tuberculosis
(Or nephritis).
Contrast Refractometer vs Urinometer methodology. | Refractometer: Refractive index (indirect)
Urinometer: Hydrometer (direct).
Benefit of Reagent Strip SG over Refractometer? | Not affected by radiopaque dye.
Contrast Cystine vs Uric Acid hexagonal shapes. | Uric Acid is strongly birefringent
(Under polarized light).
What is Polarized Microscopy required for? | Crystals and lipids
Contrast inclusion colors in Herpes vs Polyomavirus. | Herpes: Eosinophilic
Polyomavirus: Basophilic.
Define Anuria. | Near-complete suppression of urine formation.
What does Bilirubin on a dipstick usually indicate? | Liver disease or hemolysis.
Define Calcium Oxalate Dihydrate shape. | Envelope-shaped
What is the Urine Processing time limit if not refrigerated? | Older than 1 hour
Must be discarded.
Define the clinical significance of Cylindruria. | Significant presence of casts.

5.2 -

Summary

BULLET POINTS

TOPIC: RENAL PHYSIOLOGY

(Context: Renal Physiology) Renal Blood Flow (RBF) consists of approximately 1200 mL/min, which is about 25% of the total cardiac output.
(Context: Renal Physiology) Renal Plasma Flow (RPF) is measured at approximately 600–700 mL/min.
(Context: Renal Physiology) Glomerular Filtration Rate (GFR) is approximately 120 mL/min.
(Context: Renal Physiology) Ultrafiltrate Specific Gravity in the glomerulus is approximately 1.010.
(Context: Renal Physiology) Glucose renal threshold is defined as 160–180 mg/dL, representing the concentration at which reabsorption capacity is exceeded.
(Context: Renal Physiology) Active Transport during reabsorption requires energy and carrier proteins for substances like Glucose, Amino acids, Na+, and Cl-.
(Context: Renal Physiology) Proximal Convoluted Tubule (PCT) is the major site for reabsorption of glucose, amino acids, and salts, and the major site for tubular secretion.
(Context: Renal Physiology) Ascending Loop of Henle is impermeable to water but allows for the reabsorption of Chloride (Cl-).
(Context: Renal Physiology) Descending Loop of Henle is permeable to water.
(Context: Renal Physiology) Water reabsorption occurs throughout the nephron except in the ascending loop of Henle.
(Context: Renal Physiology) Albumin is normally NOT filtered by the glomerulus due to the negative charge barrier.
(Context: Renal Physiology) Tubular Secretion's major functions include eliminating non-filtered substances and regulating acid–base balance via H+ ions.

TOPIC: RENAL HANDLING MODELS (A-D)

(Context: Renal Handling) Substance A (Filtration only) is the best and ideal substance for testing Glomerular Filtration Rate (GFR).
(Context: Renal Handling) Substance B (Filtration and partial reabsorption) describes how Creatinine is handled and is widely used for GFR calculation.
(Context: Renal Handling) Substance C (Filtration and complete reabsorption) describes substances like glucose that are filtered but completely reabsorbed and not detected in urine.
(Context: Renal Handling) Substance D (Filtration and Secretion) represents substances where almost everything is found in the urine because they are both filtered and secreted.

TOPIC: CLEARANCE TESTS

(Context: Clearance Tests) Clearance is defined as the volume of plasma completely cleared of a substance per minute (mL/min).
(Context: Clearance Tests) Clearance Formula is calculated as C = (U x V) / P, where U is urine concentration, V is urine volume per unit time, and P is plasma concentration.
(Context: Clearance Tests) Ideal clearance substance must be freely filtered by the glomerulus, but NOT reabsorbed or secreted by the tubules.
(Context: Clearance Tests) Inulin clearance is an exogenous procedure, meaning the substance must be injected into the patient.
(Context: Clearance Tests) Endogenous substances used for clearance, such as creatinine, are already present in the blood and excreted at a constant rate.
(Context: Clearance Tests) Urea clearance was an endogenous procedure widely used in the past but is less common now.

TOPIC: CREATININE CLEARANCE & GFR

(Context: Creatinine Clearance) Creatinine is a waste product of muscle metabolism produced enzymatically by creatine phosphokinase from creatine.
(Context: Creatinine Clearance) Creatinine Clearance Disadvantages include:
1. Some creatinine is secreted by the tubules.
2. Chromogens in plasma can interfere with chemical analysis.
3. Medications (Gentamicin, Cephalosporins, Cimetidine) can inhibit tubular secretion or affect results.
4. Bacteria can break down urinary creatinine if left at room temperature.
5. Heavy meat consumption during the 24-hour collection period influences results.
6. It is not reliable in muscle-wasting diseases, heavy exercise, or for athletes using creatine supplements.
7. Results must be corrected for body surface area.
(Context: GFR Clinical Significance) Glomerular Filtration Rate (GFR) value does not lie in the detection of early renal disease, but rather in determining the extent of known nephron damage.
(Context: eGFR) Estimated GFR (eGFR) formulas like Cockroft-Gault and MDRD are used for routine screening because they require only serum creatinine and no urine collection.
(Context: eGFR Formulas) MDRD formula is most widely used and incorporates serum creatinine, age, gender (0.742 multiplier for women), and ethnicity (1.212 multiplier for black patients).
(Context: eGFR Formulas) Schwartz formula and the Counahan-Barrett formula are specifically used for estimating GFR in children.

TOPIC: CYSTATIN C & BETA2-MICROGLOBULIN

(Context: Cystatin C) Cystatin C is a small protein produced at a constant rate by all nucleated cells, which is filtered by the glomerulus and reabsorbed/broken down by tubules.
(Context: Cystatin C) Advantage of Cystatin C is that it is independent of muscle mass, making it ideal for pediatric, elderly, and critically ill patients.
(Context: Beta2-microglobulin) Beta2-microglobulin dissociates from human leukocyte antigens (HLA) and is removed from plasma by filtration.
(Context: Beta2-microglobulin) Beta2-microglobulin sensitivity is higher than creatinine for detecting GFR decreases, but it is not reliable in patients with immunologic disorders or malignancy.

TOPIC: TUBULAR REABSORPTION (CONCENTRATION TESTS)

(Context: Concentration Tests) Concentration tests determine the ability of the tubules to reabsorb essential salts and water.
(Context: Osmolality) Osmolality is a more accurate measure of renal concentrating ability than specific gravity because it measures only the number of particles.
(Context: Osmometry) Freezing Point Osmometer measures the depression of the freezing point (1 mol of solute lowers the freezing point by 1.86°C).
(Context: Osmometry) Vapor Pressure Osmometer measures the dew point temperature but cannot detect volatile substances like alcohol.
(Context: Osmolality Reference Values) Serum osmolality normal range is 275–300 mOsm/kg.
(Context: Osmolality Ratio) Urine:Serum Osmolality Ratio should be ≥ 3:1 after fluid restriction.
(Context: Diabetes Insipidus) ADH Challenge is used to differentiate neurogenic diabetes insipidus (lack of ADH production) from nephrogenic diabetes insipidus (renal resistance to ADH).

TOPIC: TUBULAR SECRETION AND RENAL BLOOD FLOW

(Context: PAH Test) p-aminohippuric acid (PAH) Test measures tubular secretion and renal blood flow because it is completely removed from the blood into the urine in one pass.
(Context: PAH Test) Proximal Convoluted Tubule (PCT) is the specific site where PAH is secreted from the peritubular capillaries into the urine.

DIFFERENTIATING ENTITIES FOR EXAMS

Osmolality vs. Specific Gravity: Osmolality counts ONLY the number of particles; Specific Gravity is influenced by BOTH the number and the density (size) of particles.
Neurogenic vs. Nephrogenic Diabetes Insipidus: Neurogenic DI responds to exogenous ADH (the kidneys can concentrate urine); Nephrogenic DI does NOT respond to ADH because the tubules are defective.
Creatinine vs. Cystatin C: Creatinine is affected by muscle mass and diet; Cystatin C is independent of muscle mass and is produced at a constant rate by all nucleated cells.
Inulin vs. Creatinine: Inulin is the "gold standard" exogenous substance (filtration only); Creatinine is the most common endogenous substance (filtration and some secretion).
Beta2-Microglobulin vs. Creatinine Clearance: Beta2-microglobulin is a more sensitive indicator of early GFR decrease but is useless in patients with malignancies or immune issues.
Freezing Point vs. Vapor Pressure Osmometry: Freezing point is the standard; Vapor pressure is faster and uses smaller samples but fails to detect volatile substances like Ethanol.
Active vs. Passive Transport: Active transport (e.g., Glucose in PCT) requires energy/carriers; Passive transport (e.g., Urea or Water) moves down a gradient.
Adult vs. Pediatric eGFR: Adults use Cockroft-Gault or MDRD; Children use Schwartz or Counahan-Barrett formulas.
Afferent vs. Efferent Arteriole: Afferent brings blood TO the glomerulus; Efferent carries blood AWAY from the glomerulus toward peritubular capillaries.
Ascending vs. Descending Loop of Henle: The Descending loop is water-permeable; the Ascending loop is water-impermeable (the "diluting segment").
Substance handling Case C vs. Case D: Case C is completely reabsorbed (Glucose); Case D is heavily secreted (PAH).
Fishberg vs. Mosenthal: Fishberg involves water deprivation; Mosenthal involves comparing volume/gravity of day and night samples.
Creatinine vs. Creatine: Creatine is the precursor; Creatine Phosphokinase converts it to Creatinine (the waste product).
MDRD vs. MDRD-IDMS: The constant in the formula changes from 186 to 175 to account for standardization of the creatinine assay.
Proximal vs. Distal Tubule: PCT is the major site of reabsorption and secretion; DCT is primarily for fine-tuning Na+ and acid-base (H+).
Renal Blood Flow (RBF) vs. Renal Plasma Flow (RPF): RBF is the whole blood (1200 mL); RPF is only the plasma portion (600-700 mL).
Titratable Acidity vs. Urinary Ammonia: Both are tests for tubular secretion and acid-base function.
Glucose in Urine vs. Blood: If blood glucose <160 mg/dL, it shouldn't be in urine; if >180 mg/dL, it will appear in urine due to threshold saturation.
Alcohol in Osmometry: Ethanol will increase osmolality in Freezing Point osmometers but will NOT be detected in Vapor Pressure osmometers.
Exogenous vs. Endogenous: Exogenous markers (Inulin, PAH, Radioisotopes) are more accurate but require injection; Endogenous markers (Creatinine, Urea, Cystatin C) are naturally occurring.

QA

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Define the process of Glomerular Filtration. | Plasma ultrafiltrate formation
From blood.
Define the process of Tubular Reabsorption. | Re-entry into blood
Movement from tubular filtrate back into blood.
Define the process of Tubular Secretion. | Entry into filtrate
Movement of substances from blood into the tubular filtrate.
What is the primary site of Glomerular Filtration? | Glomerulus
What is the primary site for both Tubular Reabsorption and Tubular Secretion? | Proximal Convoluted Tubule (PCT)
What substances are typically handled by Glomerular Filtration? (3) | Water, electrolytes, waste products
Which substances are primarily moved during Tubular Reabsorption? (5) | Glucose, Amino acids, Na+, Cl-, Water
Which substances are primarily moved during Tubular Secretion? (4) | H+ ions, Drugs, Toxins, PAH
What is the key metric for Glomerular Filtration? | GFR ≈ 120 mL/min
What is the key metric associated with Tubular Reabsorption? | Renal threshold
What is the major functional role of Tubular Secretion? | Acid-base regulation
What is the source and gold-standard advantage of Inulin? | Exogenous; filtered only
What are the disadvantages of using Inulin for clearance? (2) | 1) Requires infusion
2) Not endogenous
What is the source and advantage of Creatinine as a marker? | Endogenous (Muscle); constant rate
List the disadvantages of Creatinine clearance. (2) | 1) Secreted by tubules
2) Affected by meat/muscle mass
What is the source and primary advantage of Cystatin C? | All nucleated cells; independent of muscle mass
What are the disadvantages of Cystatin C? (2) | Expensive; difficult to measure
What is the source and advantage of Beta2-Microglobulin? | HLA dissociation; very sensitive to GFR decrease
In what conditions is Beta2-Microglobulin considered unreliable? (2) | Malignancy; immune disorders
What does Specific Gravity measure and what is its method? | Number AND density; Refractometry/Dipstick
What clinical factor influences Specific Gravity results? | Large molecules (protein/glucose)
What does Osmolality measure via freezing point or vapor pressure? | ONLY number of particles
Why is Osmolality clinically preferred over Specific Gravity? | More accurate
What is the method and purpose of the Fishberg Test? | Water deprivation (24h); concentration ability
What does the Mosenthal Test compare? | Day/night urine volume/gravity ratios
What is the typical value for Renal Blood Flow (RBF)? | 1200 mL/min
Approximately 25% of cardiac output.
What is the typical value for Renal Plasma Flow (RPF)? | 600–700 mL/min
What is the average Glomerular Filtration Rate (GFR)? | 120 mL/min
What is the Ultrafiltrate Specific Gravity in the glomerulus? | 1.010
What is the value for the Glucose renal threshold? | 160–180 mg/dL
What are the requirements for Active Transport during reabsorption? | Energy and carrier proteins
What is the major site for reabsorption of glucose, amino acids, and salts? | Proximal Convoluted Tubule (PCT)
What are the permeability characteristics of the Ascending Loop of Henle? | Impermeable to water; reabsorbs Chloride
What is the permeability characteristic of the Descending Loop of Henle? | Permeable to water
Where does Water reabsorption NOT occur in the nephron? | Ascending Loop of Henle
Why is Albumin normally NOT filtered by the glomerulus? | Negative charge barrier
What are the major functions of Tubular Secretion? (2) | 1) Eliminating non-filtered substances
2) Acid–base balance (H+)
Describe Substance A (Renal Handling). | Filtration only; best for GFR
Describe Substance B (Renal Handling). | Filtration and partial reabsorption
Example: Creatinine.
Describe Substance C (Renal Handling). | Filtration and complete reabsorption
Example: Glucose.
Describe Substance D (Renal Handling). | Filtration and Secretion
Almost everything found in urine.
Define Clearance. | Volume of plasma cleared per minute (mL/min)
What is the Clearance Formula? | C = (U x V) / P
What are the criteria for an Ideal clearance substance? | Freely filtered; NOT reabsorbed or secreted
What type of procedure is Inulin clearance? | Exogenous (Injected)
What type of clearance substances are Endogenous? | Already present in blood
Example: Creatinine.
What is Urea clearance historical status? | Endogenous; less common now
From what is Creatinine produced and by which enzyme? | Creatine; creatine phosphokinase
List the Creatinine Clearance Disadvantages. (7) | 1) Tubular secretion
2) Plasma chromogens
3) Medications
4) Bacteria
5) Meat consumption
6) Muscle-wasting/exercise
7) Requires BSA correction
What is the clinical significance of a Glomerular Filtration Rate (GFR) value? | Determines extent of nephron damage
Not for early detection.
What is the advantage of Estimated GFR (eGFR)? | No urine collection required
What factors are incorporated into the MDRD formula? (4) | Creatinine, age, gender, ethnicity
Which formulas estimate GFR in children? (2) | Schwartz and Counahan-Barrett
Describe the handling of Cystatin C. | Filtered; reabsorbed/broken down by tubules
Why is Cystatin C ideal for pediatric and elderly patients? | Independent of muscle mass
What is the origin of Beta2-microglobulin in plasma? | HLA dissociation
What determines the ability of tubules to reabsorb salts and water? | Concentration tests
What is the principle behind a Freezing Point Osmometer? | 1 mol solute lowers freezing point 1.86°C
What is the limitation of Vapor Pressure Osmometer? | Cannot detect volatile substances (alcohol)
What is the normal range for Serum osmolality? | 275–300 mOsm/kg
What is the expected Urine:Serum Osmolality Ratio after fluid restriction? | ≥ 3:1
What is the purpose of an ADH Challenge? | Differentiate neurogenic from nephrogenic DI
What does the p-aminohippuric acid (PAH) Test measure? | Tubular secretion and renal blood flow
Where is PAH secreted? | Proximal Convoluted Tubule (PCT)
Differentiate Osmolality vs. Specific Gravity. | Osmolality: Number only
Specific Gravity: Number and density.
Differentiate Neurogenic vs. Nephrogenic Diabetes Insipidus. | Neurogenic: Responds to ADH
Nephrogenic: Resistant to ADH.
Differentiate Creatinine vs. Cystatin C. | Creatinine: Muscle-dependent
Cystatin C: Constant rate/nucleated cells.
Differentiate Inulin vs. Creatinine. | Inulin: Gold standard/Exogenous
Creatinine: Common/Endogenous.
Differentiate Beta2-Microglobulin vs. Creatinine Clearance. | Beta2: Sensitive for early decrease
Creatinine: Less sensitive/affected by muscle.
Differentiate Freezing Point vs. Vapor Pressure Osmometry. | Freezing point: Standard
Vapor pressure: No volatiles (Ethanol).
Differentiate Active vs. Passive Transport. | Active: Requires energy/carriers
Passive: Gradient-driven.
Differentiate Adult vs. Pediatric eGFR formulas. | Adult: Cockroft-Gault/MDRD
Pediatric: Schwartz/Counahan-Barrett.
Differentiate Afferent vs. Efferent Arteriole. | Afferent: To glomerulus
Efferent: From glomerulus.
Differentiate Ascending vs. Descending Loop of Henle. | Ascending: Water-impermeable
Descending: Water-permeable.
Compare Renal Handling Case C vs. Case D. | Case C: Complete reabsorption (Glucose)
Case D: Heavily secreted (PAH).
Differentiate Fishberg vs. Mosenthal tests. | Fishberg: Water deprivation
Mosenthal: Day vs. Night samples.
Differentiate Creatinine vs. Creatine. | Creatine: Precursor
Creatinine: Waste product.
What is the difference between MDRD and MDRD-IDMS formulas? | Constant changes (186 to 175)
Standardization of assay.
Differentiate Proximal vs. Distal Tubule. | PCT: Reabsorption/Secretion
DCT: Fine-tuning/Acid-base.
Differentiate Renal Blood Flow (RBF) vs. Renal Plasma Flow (RPF). | RBF: Whole blood (1200 mL)
RPF: Plasma portion (600-700 mL).
What do Titratable Acidity and Urinary Ammonia test? | Tubular secretion; acid-base function
Predict Glucose in Urine based on blood levels. | Absent if <160 mg/dL
Present if >180 mg/dL.
How does Alcohol affect different osmometers? | Detected in Freezing Point
NOT detected in Vapor Pressure.
Differentiate Exogenous vs. Endogenous markers. | Exogenous: Injected (Inulin)
Endogenous: Naturally occurring (Creatinine).

5.3 - ABG

Summary

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ARTERIAL BLOOD GAS (ABG) ANALYSIS: OVERVIEW
Topic
General Acid-Base Balance
Respiratory Acidosis
Respiratory Alkalosis
Metabolic Acidosis
Metabolic Alkalosis

BASIC PRINCIPLES OF ACID-BASE BALANCE

The pH level is the measurement of the balance between acid and base in the body via blood.
A pH below 7.35 indicates the body is in an acidotic state (Acidosis).
A pH above 7.45 indicates the body is in an alkalotic state (Alkalosis).
Bicarbonate (HCO3-) is considered the primary "Base" in ABG analysis (Memory trick: base = Bicarbonate = double B’s).
Carbon Dioxide (CO2) acts as an acid in the body (Memory trick: Carbon diACID).
Hydrogen ions (H2) are highly acidic ions found in stomach acids and urine; an excess leads to an acidotic state.
Compensation occurs when one organ adjusts its component (acid or base) to steady the pH level and return it to a normal range when another organ is out of balance.

ROLE OF THE LUNGS AND KIDNEYS

The Lungs control the acid balance by regulating CO2 levels.
Exhaling is the main method the body uses to get rid of CO2.
A Decreased Respiratory Rate leads to less CO2 being exhaled, resulting in CO2 retention and a more acidic body state (Respiratory Acidosis).
An Increased Respiratory Rate, such as hyperventilation, causes the body to lose too much CO2, making the body more alkalotic (Respiratory Alkalosis).
The Kidneys maintain balance by controlling the excretion or retention of Hydrogen ions (acid) and Bicarbonate (base).
In an Acidotic State, the kidneys will compensate by excreting more H2 ions into the urine and retaining more HCO3.
In an Alkalotic State, the kidneys will compensate by excreting more HCO3 and retaining more H2 ions.

CLINICAL CAUSES: RESPIRATORY DISORDERS

Respiratory Acidosis is characterized by a "low and slow" respiratory rate (Memory trick: RR SlOOOw = AcidOOOsis).
Sleep apnea is a cause of Respiratory Acidosis due to airway obstruction occurring at night.
Head trauma that results in being "knocked out" can cause Respiratory Acidosis due to decreased respiratory drive.
Postoperative anesthesia recovery causes a low respiratory rate leading to Respiratory Acidosis.
CNS depressants such as Opiates (Morphine, Hydromorphone), Benzos (Diazepam), and Alcohol intoxication cause Respiratory Acidosis.
Impaired gas exchange conditions like Pneumonia (thick mucus build-up), COPD, and Asthma attacks lead to CO2 retention and Respiratory Acidosis.
Respiratory Alkalosis is caused by a fast respiratory rate where the patient "blows off" too much CO2.
Hyperventilation from anxiety or panic attacks is the hallmark cause of Respiratory Alkalosis.

CLINICAL CAUSES: METABOLIC DISORDERS

Metabolic Alkalosis can be caused by the loss of stomach acid through vomiting.
NG tube suctioning can lead to Metabolic Alkalosis because acid is being removed from the body.
Metabolic Acidosis is caused by diarrhea because the intestines hold base, and pooping it all out leaves the body acidic.
Renal Failure results in Metabolic Acidosis because broken kidneys cannot excrete H2 ions, leading to urine and acid retention.
Diabetic Ketoacidosis (DKA) is a state of Metabolic Acidosis where the body compensates with Kussmaul respirations.

ABG PROCEDURE AND TECHINQUE

Arterial Blood Gas (ABG) analysis is the best diagnostic test to evaluate oxygenation and ventilation after a traumatic brain injury.
Abnormal blood gases (ABGs) provide the most important objective data when determining if a client is hypoxic.
The Allen’s Test must be performed before an ABG procedure to determine the patency of the ulnar artery.
In the Allen’s Test, the radial and ulnar arteries are occluded while the client makes a fist; the ulnar artery is released, and color should return to the palm within 15 seconds.
The Arterial Puncture sites include the radial artery (preferred), brachial artery, and femoral artery.
Skin preparation for an arterial puncture involves cleaning the site with 70% aqueous isopropanol or iodine solution.
Pressure must be held firmly at the puncture site as the priority intervention immediately following an ABG draw.
Heparin is used as the anticoagulant in ABG syringes to prevent clotting.
Excess heparin is the most common preanalytic error in ABG collection, which can dilute the sample and alter results.
Butterfly infusion sets are not recommended for ABG collection.
Needle gauge for ABGs is typically between 19–25 gauge.

ABG INTERPRETATION AND COMPENSATION

In the Marching Band Suit method of solving ABGs, pH is primary (on top), CO2 is second, and HCO3 is third.
To Label an ABG chart, use "ABBA" (Acid-Base-Base-Acid) for pH and CO2 and "BAB" (Base-Acid-Base) for the right side for HCO3.
Uncompensated ABGs occur when the pH is not in the normal range and the compensating organ has not yet adjusted.
Partially compensated ABGs occur when the pH is still not in the normal range, but the opposite organ is working/shifting to balance the pH.
Fully compensated ABGs are identified when the pH has returned to the normal range (7.35-7.45) because of the other organ's adjustments.
When evaluating Compensation for Metabolic Acidosis, the nurse should expect an increased respiratory rate to blow off acidic CO2.
If a patient has Respiratory Acidosis, the kidneys are expected to compensate by retaining more Bicarbonate (HCO3).

DIFFERENTIATING SIMILAR CONCEPTS FOR EXAMS

Respiratory Acidosis vs. Respiratory Alkalosis: Acidosis is caused by "low and slow" breathing (CO2 retention), while Alkalosis is caused by "fast" breathing/hyperventilation (CO2 loss).
Vomiting vs. Diarrhea: Vomiting causes Metabolic Alkalosis (loss of stomach acid), whereas Diarrhea causes Metabolic Acidosis (loss of intestinal base).
Opiate Overdose vs. Panic Attack: Opiate overdose causes Respiratory Acidosis (bradypnea); a Panic attack causes Respiratory Alkalosis (tachypnea).
Uncompensated vs. Partially Compensated: In uncompensated, the pH is abnormal and the "helper" value (CO2 or HCO3) is normal; in partially compensated, the pH is abnormal but the "helper" value is also abnormal, showing it is trying to fix the pH.
Partially Compensated vs. Fully Compensated: In partially compensated, the pH is still outside the 7.35-7.45 range; in fully compensated, the pH is within the 7.35-7.45 range.
CO2 vs. HCO3: CO2 is the respiratory component (acid controlled by lungs); HCO3 is the metabolic component (base controlled by kidneys).
Acidotic State Kidney Action vs. Alkalotic State Kidney Action: In acidosis, kidneys excrete H2/retain HCO3; in alkalosis, kidneys excrete HCO3/retain H2.
Lungs vs. Kidneys Compensation Speed: Lungs compensate for metabolic issues quickly (changing RR); kidneys compensate for respiratory issues more slowly (altering ion excretion).
Allen’s Test Procedure: High-yield to remember you release the pressure on the ulnar artery specifically to check for collateral circulation.
Kussmaul Respirations: Specific to Metabolic Acidosis (like DKA) as a compensatory mechanism, not a primary respiratory disorder.
NG Suctioning vs. Renal Failure: Both are metabolic; however, NG suctioning removes acid (alkalosis), while Renal Failure retains acid (acidosis).
COPD vs. Hyperventilation: COPD is a chronic state of CO2 retention (Respiratory Acidosis); Hyperventilation is an acute state of CO2 depletion (Respiratory Alkalosis).
pH 7.32 (Acid) vs. pH 7.37 (Normal, Leaning Acid): pH 7.32 indicates partial compensation or uncompensation; pH 7.37 (in the presence of abnormal CO2/HCO3) indicates full compensation.
Radial Artery vs. Ulnar Artery: The radial artery is the site of the ABG puncture; the ulnar artery is the artery tested for patency during the Allen's Test.
Normal CO2 vs. Normal HCO3 ranges: CO2 (35-45) is simply the pH digits (7.35-7.45) without the 7; HCO3 is slightly lower (22-26).

QA

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ARTERIAL BLOOD GAS (ABG) ANALYSIS: OVERVIEW

What are the normal laboratory values for General Acid-Base Balance? (3) | pH: 7.35-7.45
CO2: 35-45
HCO3-: 22-26
What are the characteristics and kidney compensation for Respiratory Acidosis? | pH < 7.35, CO2 > 45.
Kidneys excrete H2/retain HCO3.
What are the characteristics and kidney compensation for Respiratory Alkalosis? | pH > 7.45, CO2 < 35.
Kidneys excrete HCO3/retain H2.
What are the characteristics and lung compensation for Metabolic Acidosis? | pH < 7.35, HCO3 < 22.
Lungs increase RR (Kussmaul).
What are the characteristics and lung compensation for Metabolic Alkalosis? | pH > 7.45, HCO3 > 26.
Lungs decrease respiratory rate (RR).

BASIC PRINCIPLES OF ACID-BASE BALANCE

What determines the pH level in the body? | Balance of acid and base.
What does a pH below 7.35 indicate? | Acidotic state (Acidosis).
What does a pH above 7.45 indicate? | Alkalotic state (Alkalosis).
What is the primary base used in ABG analysis? | Bicarbonate (HCO3-) (Double B's).
What component acts as an acid in the body? | Carbon Dioxide (CO2) (Carbon diACID).
What ions are highly acidic and found in stomach acid/urine? | Hydrogen ions (H2)
What is the definition of Compensation? | Organ adjusts component to steady pH.

ROLE OF THE LUNGS AND KIDNEYS

Which organ controls acid balance by regulating CO2 levels? | The Lungs
What is the main method the body uses to get rid of CO2? | Exhaling
What is the result of a Decreased Respiratory Rate? | CO2 retention (Respiratory Acidosis).
What state is caused by an Increased Respiratory Rate (hyperventilation)? | Respiratory Alkalosis (CO2 loss).
Which organ maintains balance by controlling H2 and HCO3-? | The Kidneys
How do the kidneys respond to an Acidotic State? | Excrete H2; retain HCO3.
How do the kidneys respond to an Alkalotic State? | Excrete HCO3; retain H2.

CLINICAL CAUSES: RESPIRATORY DISORDERS

What respiratory rate characterizes Respiratory Acidosis? | "Low and slow" rate.
Why does Sleep apnea cause Respiratory Acidosis? | Nighttime airway obstruction.
How does Head trauma cause Respiratory Acidosis? | Decreased respiratory drive.
Why does Postoperative anesthesia lead to Respiratory Acidosis? | Low respiratory rate.
Which CNS depressants (3) cause Respiratory Acidosis? | Opiates, Benzos, and Alcohol.
Which Impaired gas exchange conditions lead to Respiratory Acidosis? (3) | Pneumonia, COPD, and Asthma.
What causes Respiratory Alkalosis? | Fast respiratory rate (blowing off CO2).
What is the hallmark cause of Respiratory Alkalosis? | Anxiety or Panic attacks (Hyperventilation).

CLINICAL CAUSES: METABOLIC DISORDERS

How does vomiting cause Metabolic Alkalosis? | Loss of stomach acid.
Why does NG tube suctioning lead to Metabolic Alkalosis? | Acid removal from the body.
Why does Diarrhea cause Metabolic Acidosis? | Loss of intestinal base (HCO3).
How does Renal Failure cause Metabolic Acidosis? | Retention of H2/urine acid.
How does the body compensate for Diabetic Ketoacidosis (DKA)? | Kussmaul respirations (blow off CO2).

ABG PROCEDURE AND TECHINQUE

What is the best diagnostic test for oxygenation/ventilation after traumatic brain injury? | Arterial Blood Gas (ABG).
What provides the most important objective data for Hypoxia? | Abnormal blood gases (ABGs).
What is the purpose of the Allen’s Test? | Determine ulnar artery patency.
What is the procedure and normal result for the Allen’s Test? | Release ulnar; color returns < 15s.
What are the three Arterial Puncture sites? | Radial (preferred), Brachial, Femoral.
What is used for Skin preparation before arterial puncture? | 70% Isopropanol or Iodine.
What is the priority intervention immediately after an ABG draw? | Hold firm pressure at site.
Which anticoagulant is used in ABG syringes? | Heparin
What is the most common preanalytic error involving Heparin? | Excess heparin diluting sample.
Are Butterfly infusion sets recommended for ABG collection? | No.
What is the typical Needle gauge used for ABGs? | 19–25 gauge.

ABG INTERPRETATION AND COMPENSATION

In the Marching Band Suit method, what is the order of values? | pH (1st), CO2 (2nd), HCO3 (3rd).
How do you Label an ABG chart using the ABBA/BAB method? | pH/CO2: ABBA; HCO3: BAB.
When are ABGs considered Uncompensated? | pH abnormal; helper value normal.
What defines Partially compensated ABGs? | pH abnormal; helper value abnormal.
What defines Fully compensated ABGs? | pH returned to normal range.
What is the expected respiratory compensation for Metabolic Acidosis? | Increased respiratory rate.
What is the expected kidney compensation for Respiratory Acidosis? | Retaining Bicarbonate (HCO3).

DIFFERENTIATING SIMILAR CONCEPTS FOR EXAMS

Compare Respiratory Acidosis vs. Respiratory Alkalosis causes. | Acidosis: Slow breathing; Alkalosis: Fast breathing.
Compare Vomiting vs. Diarrhea in terms of acid-base balance. | Vomiting: Alkalosis; Diarrhea: Acidosis.
Compare Opiate Overdose vs. Panic Attack. | Opiate: Resp. Acidosis; Panic: Resp. Alkalosis.
Compare Uncompensated vs. Partially Compensated helper values. | Uncompensated: Helper normal; Partially: Helper abnormal.
Compare Partially vs. Fully Compensated pH levels. | Partially: pH abnormal; Fully: pH normal.
Differentiate CO2 vs. HCO3 control organs. | CO2: Lungs; HCO3: Kidneys.
Compare Acidotic vs. Alkalotic Kidney Action. | Acidosis: Retain HCO3; Alkalosis: Excrete HCO3.
Compare Lungs vs. Kidneys Compensation Speed. | Lungs: Quick; Kidneys: Slow.
Which artery is released during Allen’s Test Procedure? | Ulnar artery.
What condition is Kussmaul Respirations specific to? | Metabolic Acidosis (DKA).
Compare NG Suctioning vs. Renal Failure. | NG: Alkalosis; Renal Failure: Acidosis.
Compare COPD vs. Hyperventilation. | COPD: CO2 retention; Hyperventilation: CO2 loss.
Compare pH 7.32 vs. pH 7.37 regarding compensation state. | 7.32: Partial/Uncompensated; 7.37: Fully compensated.
Compare Radial Artery vs. Ulnar Artery roles in ABG. | Radial: Puncture site; Ulnar: Patency check.
What is the memory trick for Normal CO2 vs. Normal HCO3 ranges? | CO2: pH digits (35-45); HCO3: 22-26.

notes