Built by anaesthetists

Clinical calculators for the operating theatre

Evidence-based point-of-care tools designed by practising anaesthetists — fast, offline-capable, and free.

Works offline Mobile-first PWA No login required No data collected

Apps

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LASTCalc

Local Anaesthetic Systemic Toxicity calculator. Fractional dose mixture logic across multiple drugs, obesity-adjusted dosing, paediatric ceilings, 30+ nerve block selector, AFOi topical dosing, and print-to-EPR reports.

Regional anaesthesia LAST prevention AFOi Paediatric dosing EPR export

Open web app → ▶ Play Store (coming soon)

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Fractional mixture logic

Handles multi-drug combinations correctly — 40% lidocaine + 60% bupivacaine = 100% capacity used

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Obesity-adjusted dosing

LBW via Janmahasatian; auto-selects lean body weight when BMI ≥ 30

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Paediatric ceilings

Age-based dose limits for neonates, <6 m, 6–12 m, and >1 yr

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EPR scanning Closed beta

Camera OCR reads weight, height, age, and sex directly from an EPR sidebar

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Print to EPR

White-background report with gauge and per-drug table — paste straight into clinical notes. PDF export is live; PNG export is in beta.

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AFOi topical dosing

Per-agent bioavailability calculator for awake fibreoptic intubation, with transfer to blocks tab

Doses are based on AAGBI, DAS, and standard published references. LASTCalc is an educational and decision-support aid — it does not replace clinical judgement or local formulary guidance. Always verify doses against your departmental protocols.

Sources & citations

Local anaesthetic toxicity & maximum doses

AAGBI Safety Guideline — Management of Severe Local Anaesthetic Toxicity ↗

Association of Anaesthetists of Great Britain & Ireland, 2010. Primary source for maximum mg/kg dose limits used throughout LASTCalc.

El-Boghdadly K et al. — Local anaesthetic systemic toxicity: current perspectives ↗

Local and Regional Anesthesia, 2018; 11: 35–44. doi:10.2147/LRA.S154512. Fractional dose mixture rationale and clinical risk stratification.

AFOi topical lidocaine ceiling (9 mg/kg)

DAS Guidelines for awake tracheal intubation in adults ↗

Difficult Airway Society, Anaesthesia 2020; 75: 509–528. Source for 9 mg/kg topical lidocaine ceiling used in AFOi calculations.

Williams KA, Woodall NM et al. — Combined nebulisation and spray-as-you-go topical local anaesthesia ↗

BJA 2005; 95(4): 549–553. Demonstrated 9 mg/kg topical lidocaine does not produce toxic plasma concentrations; basis for AFOi ceiling.

Obesity-adjusted dosing

Janmahasatian M et al. — Quantification of lean bodyweight ↗

Clinical Pharmacokinetics 2005; 44(10): 1051–1065. doi:10.2165/00003088-200544100-00004. Formula used to calculate lean body weight (LBW) when BMI ≥ 30.

Devine BJ — Ideal Body Weight formula (ClinCalc reference) ↗

Original: Drug Intelligence & Clinical Pharmacy 1974; 8: 650–655 (pre-digital, no direct URL). ClinCalc provides the validated formula and clinical context used for IBW calculation in LASTCalc.

Paediatric dosing

BNF for Children — Local anaesthetics ↗

British National Formulary for Children (current edition). Age-banded maximum dose ceilings for neonates, infants, and children.

Suresh S et al. (ESRA/ASRA) — Recommendations on local anaesthetic dosage in paediatric regional anaesthesia ↗

Regional Anesthesia and Pain Medicine 2018; 43(2): 211–216. doi:10.1097/AAP.0000000000000702. Joint ESRA/ASRA committee recommendations informing age-banded dose ceilings used in LASTCalc.

Nerve block volumes & drug selection

NYSORA — Clinical Pharmacology of Local Anesthetics ↗

Hadzic A (ed.). Volumes, concentrations, and expected durations for individual nerve blocks; maximum dose guidance by agent.

Bardsley H et al. — Cardiac and CNS toxicity of levobupivacaine: strengths of evidence for advantage over bupivacaine ↗

Drug Safety 2002; 25(3): 153–163. Evidence basis for preferring levobupivacaine at vascular-adjacent blocks where inadvertent IV injection is a risk.

Disclaimer

Educational and decision-support use only. PeriOp Digital tools, including LASTCalc, are intended to assist trained clinicians in calculating drug doses based on published reference data. They do not replace clinical judgement, institutional protocols, or the guidance of a responsible consultant.

Dose references. Maximum doses are derived from AAGBI, DAS, and standard published anaesthetic references. Local formularies and departmental protocols may differ — always verify doses against your own institution's guidance before administering any drug.

Patient safety. No calculator can account for all individual patient factors. Clinical decisions must be made by a qualified practitioner who has assessed the patient directly. If in doubt, seek senior advice.

No liability. PeriOp Digital and its developers accept no liability for clinical decisions made using these tools. Use is entirely at the clinician's own risk.

Data privacy. No patient data is collected, stored, or transmitted. All calculations run locally in your browser.