@pedi-bp/core

Pediatric blood pressure percentile calculator — AAP 2017, NHLBI, ERICA (Brazilian), Lo 2013, Gemelli.

Zero dependencies. Works in Node.js, browsers, and edge runtimes.

Features

• 5 data sources: AAP 2017, NHLBI, ERICA (Brazilian data), Lo 2013, Gemelli 1990
• Automatic cascade: selects the best source based on age, sex, and height availability
• Classification: AAP 2017 guidelines (percentile-based < 13y, absolute thresholds >= 13y)
• Transparent source reporting: shows which source was used and available alternatives
• Height percentile: CDC 2000 growth charts embedded (no external dependency)
• Input validation: rejects NaN, Infinity, out-of-range values
• i18n: pt-BR, en, es
• Independently derived data: avoids GPL-2 licensing constraints

Data Sources

| Source | Age Range | Height | Method | |--------|-----------|--------|--------| | Gemelli 1990 | 1–9 months | No | Gaussian | | AAP 2017 (Flynn) | 1–17 years | Yes (7 percentile bins) | Gaussian | | NHLBI Fourth Report | 1–17 years | Yes / P50 fallback | Gaussian | | Lo 2013 | 3–17 years | No | Gaussian | | ERICA (Brazil) | 12–17 years | Yes (CDC z-score) | Polynomial regression |

Automatic Cascade (source = 'auto')

Gemelli (<12mo) → AAP 2017 (1–12y + height) → ERICA (12–17y + height)
                → Lo 2013 (3–17y, no height) → NHLBI (12–35mo, P50 fallback)

Install

npm install @pedi-bp/core

Usage

import { calculateBp, bpAtPercentile, availableSources } from '@pedi-bp/core';

// Calculate BP percentiles and classification
const result = await calculateBp({
  sex: 'male',
  ageMonths: 120,   // 10 years
  heightCm: 140,
  systolic: 115,
  diastolic: 75,
});

console.log(result.classification.label);    // "PA Elevada"
console.log(result.source.used);             // "aap2017"
console.log(result.systolic?.percentile);    // ~92

// Inverse: BP value at a given percentile
const bp95 = await bpAtPercentile({
  sex: 'male',
  ageMonths: 120,
  heightCm: 140,
  percentile: 95,
  type: 'systolic',
});

// List available sources for a patient
const sources = availableSources('male', 120, 140);

API

calculateBp(input, locale?): Promise<BpResult>

Calculate BP percentiles and classification.

Input:

• sex: 'male' | 'female'
• ageMonths: 1–204
• heightCm?: height in cm (enables height-dependent lookup)
• systolic?: systolic BP in mmHg
• diastolic?: diastolic BP in mmHg
• source?: 'auto' (default) | 'aap2017' | 'nhlbi' | 'erica' | 'lo2013'

bpAtPercentile(input): Promise<number>

Compute BP value at a given percentile (inverse function).

availableSources(sex, ageMonths, heightCm?): BpSourceInfo

List available sources for a given patient profile.

Classification (AAP 2017)

Children < 13 years (percentile-based)

| Category | SBP | DBP | |----------|-----|-----| | Normal | < P90 | < P90 | | Elevated | P90 to < P95 or >= 120/80 | P90 to < P95 | | HTN Stage 1 | P95 to P95+12 | P95 to P95+12 | | HTN Stage 2 | >= P95+12 | >= P95+12 |

Adolescents >= 13 years (absolute thresholds)

| Category | SBP | DBP | |----------|-----|-----| | Normal | < 120 | < 80 | | Elevated | 120–129 | < 80 | | HTN Stage 1 | 130–139 | 80–89 | | HTN Stage 2 | >= 140 | >= 90 |

Classification uses the worst of SBP and DBP.

Formulas

• Gaussian: z = (BP - mean) / SD, percentile = normal CDF
• ERICA: polynomial regression BP = f(age, z_height) with 4th-degree terms
• Height percentile: CDC 2000 LMS method (recumbent < 24mo, standing >= 24mo)

Data Sources

• AAP 2017: Flynn JT et al. Pediatrics 2017;140(3):e20171904
• ERICA: Jardim TV et al. J Pediatr (Rio J) 2020;96(2):168-176
• Gemelli: Gemelli M et al. Eur J Pediatr 1990;149(5):318-20
• Lo 2013: Lo JC et al. Pediatrics 2013;131(2):e415-24
• NHLBI: Pediatrics 2011;128(Suppl 5):S213-56
• CDC 2000: Kuczmarski RJ et al. Adv Data 2000;(314):1-27

License

MIT