Disorders of Extracellular Fluid Volume: Basic Concepts Mnemonics

Question 1

What does the mnemonic ‘RAAS the ROOF’ help remember?

Answer 1

The RAAS cascade and its effects on sodium retention and fluid overload

R: Renin, A: Angiotensin II, A: Aldosterone, S: Sodium retention, O: Output reduction, O: Overload, F: Fluid retention

Question 2

What are the three major baroreceptor locations according to the mnemonic ‘CAP the Volume’?

Answer 2

• Carotid sinus (CN IX)
• Aortic arch (CN X)
• Pulmonary veins/atria (low-pressure)

This mnemonic aids in recalling the afferent sensors involved in volume regulation.

Question 3

What does ‘SAD ANP’ represent in the context of efferent pathways?

Answer 3

• Sympathetic (SNS)
• ADH
• Diuresis inhibition
• ANP (suppressed in volume depletion)

This mnemonic highlights the opposing forces of fluid retention and excretion.

Question 4

What conditions are represented by the mnemonic ‘CHiN’?

Answer 4

• Cirrhosis
• Heart failure
• Nephrotic syndrome

These are classic edematous disorders associated with decreased effective arterial blood volume (EABV).

Question 5

What do the elements of ‘POPCORN’ explain about Starling Forces?

Answer 5

• Pₐ (arterial pressure) ↑ → Outflow (filtration)
• Pᵥ (venous pressure) ↑ → Overload (edema)
• Capillary oncotic (Πc) ↓ → Retention (interstitial fluid)
• Nephrotic (protein loss) worsens Πc

This mnemonic links physiological forces to clinical scenarios involving edema.

Question 6

What concept does the mnemonic ‘FAKE Volume’ illustrate?

Answer 6

• Failure (HF) → Arterial underfill
• Ascites (cirrhosis) → Kidney thinks ‘low volume’
• ECF ↑ but EABV ↓

This highlights the disconnect between extracellular fluid and effective arterial blood volume in edematous states.

Question 7

What diuretic targets are identified in the mnemonic ‘LOOP the TZ’?

Answer 7

• Loop diuretics → Overload (acute edema)
• Thiazides → Zero in on HTN/CKD
• K⁺-sparing → Spare K⁺ (opposes aldosterone)

This mnemonic matches drug classes to their clinical uses in fluid management.

Question 8

What does the ‘1-Up’ mnemonic indicate about the urinary Na⁺/K⁺ ratio?

Answer 8

> 1: Loop/thiazide working (↑ Na⁺ excretion)
<1: Add K⁺-sparing (aldosterone dominant)

This simple threshold aids in adjusting diuretic therapy based on urinary electrolyte excretion.

Question 9

What findings are included in the mnemonic ‘WET LEGS’ for edema?

Answer 9

• Weight gain
• Elevated JVP
• Third heart sound
• Low albumin (nephrotic)
• EABV ↓
• Glycocalyx dysfunction
• Skin pitting

These are classic clinical findings across various volume disorders.