feat(shock-index): add Shock Index calculator (#16)

assets/version.json

@@ -1 +1 @@
-{"version": "0.1.13"}
+{"version": "0.1.14"}

lib/features/home/presentation/tool_registry.dart

@@ -124,6 +124,12 @@ class ToolRegistry {
         icon: Icons.thermostat,
         route: '/hipertermia',
         category: ToolCategory.signosValores),
+    ToolEntry(
+        id: 'shock_index',
+        name: 'Indice de Shock',
+        icon: Icons.show_chart,
+        route: '/shock-index',
+        category: ToolCategory.signosValores),
     // Oxigenoterapia
     ToolEntry(
         id: 'o2_calculator',

lib/features/shock_index/domain/shock_index_calculator.dart

@@ -0,0 +1,92 @@
+import 'package:emerkit/shared/domain/entities/severity.dart';
+
+class ShockIndexResult {
+  final double shockIndex;
+  final double modifiedShockIndex;
+  final double tam;
+  final Severity severity;
+  final Severity msiSeverity;
+  final double? sipaThreshold;
+
+  const ShockIndexResult({
+    required this.shockIndex,
+    required this.modifiedShockIndex,
+    required this.tam,
+    required this.severity,
+    required this.msiSeverity,
+    this.sipaThreshold,
+  });
+}
+
+class ShockIndexCalculator {
+  const ShockIndexCalculator();
+
+  ShockIndexResult calculate({
+    required int heartRate,
+    required int systolicBP,
+    required int diastolicBP,
+    bool isPediatric = false,
+    int? ageYears,
+  }) {
+    final si = heartRate / systolicBP;
+    final tam = diastolicBP + (systolicBP - diastolicBP) / 3;
+    final msi = heartRate / tam;
+
+    double? sipaThreshold;
+    Severity severity;
+
+    if (isPediatric && ageYears != null) {
+      sipaThreshold = _sipaThresholdForAge(ageYears);
+      severity = _sipaSeverity(si, sipaThreshold);
+    } else {
+      severity = _adultSeverity(si);
+    }
+
+    return ShockIndexResult(
+      shockIndex: si,
+      modifiedShockIndex: msi,
+      tam: tam,
+      severity: severity,
+      msiSeverity: _msiSeverity(msi),
+      sipaThreshold: sipaThreshold,
+    );
+  }
+
+  static Severity _adultSeverity(double si) {
+    if (si < 0.7) {
+      return const Severity(label: 'Normal', level: SeverityLevel.mild);
+    }
+    if (si < 1.0) {
+      return const Severity(
+          label: 'Normal-alto', level: SeverityLevel.moderate);
+    }
+    if (si <= 1.3) {
+      return const Severity(label: 'Elevado', level: SeverityLevel.severe);
+    }
+    return const Severity(label: 'Muy elevado', level: SeverityLevel.severe);
+  }
+
+  static Severity _msiSeverity(double msi) {
+    if (msi >= 0.7 && msi <= 1.3) {
+      return const Severity(label: 'Normal', level: SeverityLevel.mild);
+    }
+    if (msi <= 1.7) {
+      return const Severity(label: 'Elevado', level: SeverityLevel.moderate);
+    }
+    return const Severity(label: 'Muy elevado', level: SeverityLevel.severe);
+  }
+
+  static double _sipaThresholdForAge(int age) {
+    if (age <= 3) return 1.22;
+    if (age <= 6) return 1.2;
+    if (age <= 12) return 1.0;
+    return 0.9; // 13-17
+  }
+
+  static Severity _sipaSeverity(double si, double threshold) {
+    if (si < threshold) {
+      return const Severity(label: 'Normal', level: SeverityLevel.mild);
+    }
+    return const Severity(label: 'SIPA elevado', level: SeverityLevel.severe);
+  }
+}

lib/features/shock_index/domain/shock_index_data.dart

@@ -0,0 +1,65 @@
+import 'package:emerkit/shared/domain/entities/clinical_reference.dart';
+
+class ShockIndexData {
+  ShockIndexData._();
+
+  static const infoSections = <String, String>{
+    'Que es':
+        'El Indice de Shock (SI) es el cociente entre la frecuencia cardiaca '
+            '(FC) y la tension arterial sistolica (TAS). Es una herramienta '
+            'rapida para detectar shock e hipovolemia oculta, mas sensible que '
+            'FC o TAS por separado, especialmente en la fase compensatoria.',
+    'Formulas': 'Indice de Shock (SI) = FC / TAS\n\n'
+        'Indice de Shock Modificado (MSI) = FC / TAM\n'
+        'TAM = TAD + 1/3 x (TAS - TAD)\n\n'
+        'SIPA (pediatrico) = misma formula con umbrales ajustados por edad.',
+    'Interpretacion adultos': 'SI < 0.7: Normal\n'
+        'SI 0.7 - 0.99: Normal-alto (vigilar)\n'
+        'SI 1.0 - 1.3: Elevado - hipovolemia o shock descompensado\n'
+        'SI > 1.3: Muy elevado - shock severo, resucitacion inmediata\n\n'
+        'MSI 0.7 - 1.3: Rango normal\n'
+        'MSI > 1.3: Anormal, mayor riesgo de mortalidad',
+    'SIPA pediatrico': '1-3 anos: anormal si >= 1.22\n'
+        '4-6 anos: anormal si >= 1.20\n'
+        '7-12 anos: anormal si >= 1.00\n'
+        '13-17 anos: anormal si >= 0.90',
+    'Aplicaciones clinicas':
+        'Triaje en trauma: predice necesidad de transfusion masiva e ingreso UCI.\n'
+            'Deteccion de hemorragia oculta en fase compensatoria.\n'
+            'Screening de sepsis (MSI >= 1.0).\n'
+            'Emergencias obstetricas: hemorragia postparto.\n'
+            'Triaje en urgencias: asignacion de acuidad y recursos.',
+    'Limitaciones': 'No usar como criterio diagnostico unico.\n'
+        'Confundido por: betabloqueantes, marcapasos, HTA basal, '
+        'embarazo, dolor, ansiedad.\n'
+        'Umbrales pediatricos especificos por edad.\n'
+        'No validado en pacientes con arritmias o medicacion cronotropica.',
+  };
+
+  static const references = [
+    ClinicalReference(
+      'Allgower M, Burri C. Schockindex. '
+      'Dtsch Med Wochenschr. 1967;92(43):1947-1950.',
+    ),
+    ClinicalReference(
+      'Koch E, et al. Shock index in the emergency department: '
+      'utility and limitations. Open Access Emerg Med. 2019;11:179-199.',
+    ),
+    ClinicalReference(
+      'Liu YC, et al. Modified shock index and mortality rate of '
+      'emergency patients. World J Emerg Med. 2012;3(2):114-117.',
+    ),
+    ClinicalReference(
+      'Acker SN, et al. Shock index, pediatric age-adjusted (SIPA). '
+      'J Pediatr Surg. 2015;50(2):331-334.',
+    ),
+    ClinicalReference(
+      'Schroll R, et al. Shock index as predictor of massive '
+      'transfusion and mortality. Crit Care. 2023;27(1):61.',
+    ),
+    ClinicalReference(
+      'Mutschler M, et al. The Shock Index revisited — a fast guide '
+      'to transfusion requirement? Crit Care. 2013;17(4):R172.',
+    ),
+  ];
+}