Renal Oxygenation Calculator (Design Mockup)

Inputs

Enter values → Calculate (later)

Anthropometrics (used for LBM, default kidney mass estimate)

Units:

US Metric

Weight

Height

Sex (for LBM equation later)

Age (optional)

Important: Non-Standard Renal Anatomy Considerations

For patients with single kidney (congenital or post-nephrectomy), horseshoe kidney, renal transplant, or marked asymmetry/atrophy, both:

Renal mass (affects estimated O₂ demand / VO₂), and
Renal blood flow distribution (affects effective O₂ delivery / DO₂)

may differ from standard assumptions. Consider available imaging, functional studies, and clinical context when interpreting results for anatomical variants.

In these scenarios, results are best treated as screening-level physiology, not precise organ quantification.

Kidney Measurements (CT / Ultrasound) (optional override)

Enter 3 dimensions per kidney

Kidney mass override (g) — direct entry

Assumed kidney density (g/mL)

Right kidney L × W × D

Length

Width

Depth

Left kidney L × W × D

Length

Width

Depth

Tip: Kidney dimensions are expected in centimeters (cm). If values appear unusually large (e.g., entered in millimeters), they will be automatically converted. Decimal commas (e.g., 11,5) are also accepted.

Oxygen Content & Hemodynamics (current patient state)

NICOM CO + labs

Hemoglobin (g/dL)

Hematocrit (%)

SaO₂ (%)

Cardiac Output (L/min) — NICOM

VO₂ coefficient k (mL O₂/min/g kidney)

NOTE: k is a modeling constant that links kidney mass to estimated renal VO₂. Leave blank to use the default (0.08).

Baseline renal fraction of CO (normal physiology)

Effective renal fraction of CO (after modifiers)

"Effective Renal Fraction" represents usable renal oxygen-delivery fraction (not directly measured RBF). Baseline is set within the normal range (default 0.25). Modifiers (starting with CHF) reduce the effective fraction used in downstream calculations; baseline remains normal physiology.

Effective Renal Delivery Modifiers (affect effective renal fraction)

pick what applies

CHF / Cardiorenal physiology Targets common teaching ranges using baseline-normal physiology: CHF severity

Cirrhosis / HRS physiology Caps effective renal delivery fraction (conservative tiers): Cirrhosis stage (tier)

Warning: Vasopressors may raise blood pressure yet fail to improve, and may worsen renal medullary oxygenation while improving oxygenation of the renal cortex. Their net renal effects are highly context-dependent and therefore are not included in this calculation.

Renal Metabolic Efficiency Modifiers (affect VO₂/“efficiency coefficient”)

worst single modifier wins

AKI / tubular injury Increases inefficiency (coeff. later)

CKD (≥ stage 3) Increases inefficiency (coeff. later)

Sepsis physiology Potential mitochondrial dysfunction (coeff. later)

Efficiency coefficient (ε) - manual override

Auto-Applied efficiency coefficient

Diuretics (optional, future)

Inner Medulla Model Settings (conservative, plumbing-limited)

used for IM risk metrics

Inner medullary DO₂ fraction (fixed)

Inner medullary VO₂ fraction (of total renal VO₂)

Assumed inner medullary max extraction (OER_max)

Baseline hemoglobin for ΔOER (optional)

Locked assumptions: Inner medullary DO₂ is modeled as a fixed 2% of renal DO₂ (best-case, plumbing-limited). No dynamic redistribution is assumed. IM VO₂ fraction and OER_max are conservative modeling controls for sensitivity analysis; they do not change systemic/renal outputs.

END IM SECTION DISABLED -->

Design-only: buttons do not function yet. Next step: wiring calculation logic + validation + mobile stress-testing.

Outputs

Read-only fields (placeholders)

Body & Kidney Metrics (derived)

baseline physiology

BMI kg/m²

(pending)

BSA (Mosteller) m²

(pending)

Lean body mass kg

(pending)

Kidney volume (total) mL

(pending)

Kidney mass (total) g

(pending)

Kidney mass source

(pending)

Total blood volume (Nadler) L

(pending)

Hemoglobin mass g

(pending)

Global DO₂ Index (DO₂i) mL/min/m²

(pending)

Significant global oxygen delivery deficit detected.

Systemic DO₂ index of XX mL/min/m² is below published safety thresholds associated with a significantly increased risk of AKI, even before renal-specific modeling.

Critical global oxygen delivery deficit detected.

Systemic DO₂ index of XX mL/min/m². DO₂i values below YY mL/min/m² are associated with a critical risk of organ dysfunction in published research literature, independent of renal-specific modeling.

Oxygen Content & Delivery (systemic → renal)

CaO₂, DO₂

CaO₂ mL O₂/dL

(pending)

Total O₂ carrying capacity (systemic) mL O₂/min

(pending)

Renal Blood Flow L/min

(pending)

DO₂ (renal, effective) mL O₂/min

(pending)

Consumption, Stress, and Targets (VO₂, OER, Hb solver)

core logic

VO₂ (renal estimate) mL O₂/min

(pending)

VO₂ coefficient mL/min/g

(default 0.08)

Renal metabolic efficiency (applied) unitless

(pending)

OER (Raw) %

(pending)

OER (Augmented) %

(pending)

Required OER (target) %

15% (default target placeholder)

Hemoglobin needed to reach OER=15% g/dL

(pending)

Hemoglobin deficit g/dL

(pending)

Later: “Hb needed” will be solved assuming CO and effective renal fraction are held constant (counterfactual), with transparent assumptions.

Inner Medulla Guidance (primary vulnerability target)

Derived from renal OER (slope model). IM baseline OER target = 85%.

IM OER (derived, uncapped) %

(pending)

IM OER target (baseline) %

85.0

IM status

(pending)

Hb needed to reach IM OER target (85%) g/dL

(pending)

ΔHb to IM target g/dL

(pending)

Hb needed to reach renal OER target (15%) g/dL

(pending)

Dominant Hb target (max) g/dL

(pending)

Guidance

(pending)

Global DO₂i if Hb corrected to IM OER target of 85% mL/min/m²

(pending)

Global DO₂i if Hb corrected to renal OER target of 15% mL/min/m²

(pending)

This IM section is derived from the renal augmented OER using a conservative slope model anchored at: renal OER 15% → IM OER 85% (baseline target) and renal OER 35% → IM OER 100% (failure point). IM OER is shown uncapped for research purposes.