TheraCALC · Acid-Base Safety & Governance

This document outlines how the TheraCALC Acid-Base Calculator is positioned and designed from a safety and governance standpoint. It is written for leadership, legal counsel, and clinical governance review, not for developers or end users.

1 — Role of the Tool

The acid-base calculator is clinical decision support software for licensed pharmacists and prescribers. It interprets values entered by the clinician, applies commonly used acid-base formulas, and returns pattern-based guidance. It does not issue orders, make autonomous diagnoses, or access external data.
Outputs such as diagnostic labels, fluid suggestions, and dosing examples are framed as pattern-based guidance requiring clinical interpretation.
The tool is currently intended for inpatient and acute care use. It is not designed or marketed for ambulatory, retail, or patient-facing settings.
Result screens reinforce that the clinician retains full responsibility for diagnosis and treatment. "Consider" leads all therapeutic suggestions; drug-specific outputs reference local institutional protocol where applicable.
The tool is best understood as three things: a calculator that automates common acid-base formulas; a teaching aid that shows its reasoning step by step; and a checklist that prompts for key data the clinician may not yet have (albumin, urine chloride, serum osmolality).

Runtime independence Recommendations are generated using the proprietary TheraIQ engine developed and maintained in-house. TheraCALC does not rely on any third-party clinical decision-support service.

2 — Data Transparency & Reasoning

The calculator works only with what the clinician enters. It does not connect to the medical record, transmit data to any server, or retain patient information between sessions.
A "How We Got Here" tab shows the stepwise logic used — pH interpretation, primary process identification, anion gap calculation, compensation check, and mixed-disorder screening — in numbered steps that mirror commonly taught algorithms.
When key values are missing, the tool does not extrapolate; it labels outputs as estimated or limited and recommends specific additional data that would improve interpretation.
A confidence badge is displayed so the clinician can see at a glance how complete the current interpretation is.
Clinical indices of low decision value in a given pattern (e.g., UAG in clear lactic acidosis) are demoted in the output hierarchy to reduce cognitive noise.
The tool cross-checks pH against HCO₃ and PaCO₂ using the Henderson-Hasselbalch equation and flags implausible combinations as likely entry errors before they influence clinical output where feasible.

3 — Pattern-Based Language, Not Diagnoses

All diagnostic and differential language is deliberately framed as probabilistic and pattern-based. The tool suggests; it does not diagnose.

Discouraged language	Preferred language patterns in the tool
Diagnoses stated directly (DKA, salicylate toxicity, RTA Type 4)	"Pattern may be consistent with…" / "Findings can be seen in…"
"Confirms mixed disorder"	"Compensation pattern may suggest an additional process"
"Determines the treatment pathway"	"Directs the primary management branch — send urine Cl⁻ to help confirm"
"Rules out"	"Does not exclude"
"Proves"	"Supports" / "Is compatible with"

Differential disclaimer Where differential or mixed-disorder lists are displayed, a footer is used: "Listed conditions are pattern-based possibilities, not exhaustive or definitive diagnoses. Integrate with history, examination, imaging, and additional laboratory data."

4 — Fluids & Dosing as Guidance, Not Orders

Fluid and dosing outputs are labeled as estimates and examples. No output is framed as a medication order.

Output	How it is labeled	Key safeguards
Interventions card	Guidance only; verify with clinical context and local protocol	Items use "Consider…" language; protocol references used where appropriate
Bedside dose calculations	Estimates only; not medication orders	Formula assumptions (adult, not on dialysis, simplified bedside formulas) stated inline
Potassium replacement	Example regimen; follow institutional protocol	CrCl ≥ 30 mL/min assumption explicit; ECG monitoring suggested; renal adjustment noted
Bicarbonate dosing	Bicarbonate may be considered (indication-dependent)	BICAR-ICU trial cited; target pH and risks (volume overload, hypernatremia, hypokalemia) stated
HCl / arginine HCl	ICU-only, protocol-driven; consult nephrology or critical care where available	Contraindications checked against entered labs; central line requirement noted
Acetazolamide	Consider acetazolamide (refractory alkalosis)	CrCl gates enforced; potassium check required; sulfa allergy listed as contraindication

5 — Bicarbonate Therapy Safety Guidance

The tool explicitly discourages routine bicarbonate infusion in lactic acidosis per current evidence (BICAR-ICU trial)
Bicarbonate is flagged as not recommended unless pH <7.10 with cardiovascular collapse or select specific indications
The tool explains the mechanism — bicarb generates CO₂ acutely, worsening intracellular acidosis — to support clinician understanding rather than blind compliance

Reference Jaber S, et al. Sodium bicarbonate therapy for patients with severe metabolic acidaemia in the intensive care unit (BICAR-ICU). Lancet. 2018;392(10141):31-40.

6 — Fluid Recommendation Safety

Balanced crystalloid (LR) is recommended over normal saline for resuscitation in HAGMA — consistent with SMART and SALT-ED trial evidence
The tool explicitly addresses the "LR has lactate" misconception — LR does not meaningfully worsen serum lactate in lactic acidosis
Volume recommendations (e.g., 30 mL/kg) include explicit caveats that final fluid choice must follow hemodynamic status and local protocol
High-risk populations (CHF, CKD, advanced age) are flagged as warranting modified fluid approaches with earlier vasopressor consideration

7 — Lactate Trajectory Guidance

Serial lactate monitoring is explicitly recommended with defined trajectory targets
Target: ≥10% lactate clearance at 1 hour, ≥20% at 2 hours (Jansen et al, 2010)
Failure to clear is flagged with a differential: occult source, inadequate source control, impaired hepatic clearance, mitochondrial toxin, or persistent hypoperfusion
Escalation triggers (ICU, vasopressors) are explicitly stated when MAP and urine output targets are not met

Reference Jansen TC, et al. Early lactate-guided therapy in ICU patients. Am J Respir Crit Care Med. 2010;182(6):752-761.

8 — Handling Uncertainty & Incomplete Data

A confidence indicator (BMP-only / ABG-confirmed / urine-informed / multi-source) is shown so the quality of the interpretation is visible at a glance.
A separate action-urgency indicator fires independently of acid-base severity — preventing a mild pH deviation from obscuring a clinically critical electrolyte or perfusion situation (for example, pH 7.38 with potassium 6.8 mEq/L is still treated as urgent).
When classification is indeterminate or key values are missing, the tool indicates this explicitly rather than forcing a label. Standard phrases include: "No clear primary acid-base disorder identified yet" and "Mixed-disorder assessment is limited without ABG (pH and PaCO₂)."
The "How We Got Here" tab carries a footer: "This stepwise summary explains how the calculator interpreted the current values using commonly cited bedside rules. It is not a complete diagnostic algorithm and should be integrated with history, examination, imaging, and clinical judgment."

9 — Alignment with Teaching Frameworks

The calculation sequence — primary process, anion gap with albumin correction, compensation verification, delta-delta ratio, mixed-process screening, and urine electrolyte interpretation — is modeled on stepwise algorithms commonly used in internal medicine and critical care education.
This is intended to keep the tool transparent, easy to critique, and straightforward to override; it is not designed to function as a black box.
The "How We Got Here" tab shows each major step, the formula applied, the calculated value, and a brief clinical interpretation — with explicit notes when a step relies on a population estimate, a default assumption, or incomplete data.

10 — Intended Use & Responsibilities

Dimension	Position
Intended users	Licensed pharmacists and prescribers with training in acid-base interpretation; not intended for patients or lay users
Clinical setting	Currently intended for inpatient and acute care; not for ambulatory, retail, or patient-facing use
Clinician responsibility	Clinicians retain full responsibility for verifying all calculations and treatment decisions
Beta status	A BETA label is displayed in the site navigation, calculator header, and homepage card; all outputs should be independently verified
Error reporting	An in-app feedback mechanism routes reports to the clinical pharmacist developer for review
Improvement process	Clinical feedback from practicing pharmacists and prescribers informs prioritization; version history is maintained in source control

11 — Regulatory & Institutional Considerations

TheraCALC operates as a browser-based reference tool — all computation runs locally in the clinician's browser; no patient data is transmitted to TheraCALC servers
The tool does not store, process, or transmit protected health information (PHI) and is not intended to function as a HIPAA business associate
Healthcare organizations should evaluate TheraCALC under their own policies for browser-based clinical reference tools
TheraCALC is categorized as a legitimate, non-malicious clinical reference tool by major security-vendor URL-categorization and threat-intelligence services, including Palo Alto Networks, Fortinet FortiGuard, and Cisco Talos.

For institutional IT and security teams Additional documentation including security questionnaire responses and network whitelisting support is available upon request at [email protected]

12 — Known Limitations

BMP-only classification. Without pH and PaCO₂, the calculator cannot confirm acidemia or alkalemia, verify compensation, or reliably detect mixed disorders. BMP-only outputs are labeled as provisional.
Renal function estimation. Cockcroft-Gault CrCl is used for drug dosing gates. This equation may overestimate GFR in frail or sarcopenic patients; cystatin C-based eGFR is preferred in those populations where available.
No renal-hepatic interaction modeling. The tool does not account for the effect of combined organ dysfunction on acid-base status.
Compensation formulas. Winters formula and standard respiratory compensation ranges are bedside approximations derived from population data. Individual variation is expected.
Chronic compensation. The tool distinguishes acute from chronic respiratory compensation but relies on user context for correct selection.
Pediatric use. Adult normal ranges and thresholds are used throughout. Pediatric acid-base interpretation is outside the current scope of this tool.
Static reference ranges. Normal ranges (AG cutoff 12, HCO₃ 22-26) are bedside standards and may differ from individual lab reference ranges.
No prospective validation. The calculator has undergone internal unit testing across multiple clinical presets and targeted logic scenarios. A formal prospective clinical validation study has not yet been completed.
Mixed-disorder confidence. Detection relies on compensation thresholds that carry inherent variance. Unusual clinical scenarios (e.g., triple or complex mixed disorders) may generate false positives or miss concurrent processes.

Summary The TheraCALC Acid-Base Calculator is designed as a transparent, pattern-based decision support aid. It does not issue orders, make autonomous diagnoses, or replace clinical judgment. Outputs are intended to direct the clinician back to the patient's clinical picture, measured values, and local protocols. The tool is in active beta development; all outputs should be independently verified by the responsible clinician.

Contact

Questions, governance review requests, or discrepancy reports: [email protected]
All reports reviewed by the clinical pharmacist developer. No PHI is required in discrepancy reports.

Acid-Base Calculator — Safety & Governance