Hospital dos Lusíadas
Alterações do metabolismo cálcio fósforo
Hipocalcemia
Hipercalcemia
Pós graduação - Emergências Médicas
João Albuquerque Gonçalves
Assistente Hospitalar de Nefrologia
CÁLCIO - FÓSFORO
Metabolismo fosfo-cálcico
• DRC:
– Agravamento de função renal associado ao hiperparatiroidismo
secundário
– Aumento do FGF23
– Hipocalcémia
– Défice de vit D2
– Hiperfosfatémia
Aumento de
síntese de PTH
Consequências da DRC-DMO
Se não se tratar devidamente o HPTS:
– Osteodistrofia renal
• Alteração da renovação, mineralização, volume
• Alteração do crescimento linear e robustez óssea
– Calcificações:
• vasculares ou de tecidos moles
• Extra-esqueléticas
– Alterações Laboratoriais
• Alterações do metabolismo do cálcio
• Hiperfosfatémia
• Hipocalcemia
Consequências da DRC-DMO
– Consequências clínicas:
• Fraturas
• Dores ósseas e musculares
• Necrose avascular
• Aumento de risco de mortalidade e hospitalizações (eventos cardiovasculares)
• Hiperplasia da Paratiróide
Objectivos na DRC/HD
• iPTH entre 150-300
(ou entre 2-9x o valor de base – 150-600)
• Fósforo – 3,5 – 5,5
• Cálcio – 8,2 – 10,2
Fósforo
BMC Nephrol.2013 Apr 17;14:88. doi: 10.1186/1471-2369-14-88.
Is there an association between elevated or low serum levels of phosphorus, parathyroid hormone, and calcium and mortality in patients with end stage renal disease? A meta-analysis.
Cálcio
BMC Nephrol.2013 Apr 17;14:88. doi: 10.1186/1471-2369-14-88.
Is there an association between elevated or low serum levels of phosphorus, parathyroid hormone, and calcium and mortality in patients with end stage renal disease? A meta-analysis.
PTHi
BMC Nephrol.2013 Apr 17;14:88. doi: 10.1186/1471-2369-14-88.
Is there an association between elevated or low serum levels of phosphorus, parathyroid hormone, and calcium and mortality in patients with end stage renal disease? A meta-analysis.
HPTS - Como tratar?
• Quelantes de fósforo
(com ou sem cálcio)
• Calcitriol
• Análogos da Vit D
Terapêutica disponível
• Alfacalcidol 0,25; 0,5; 1 mcg até 3 mcg/dia
• Calcitriol per os 0,25 até 1 mcg/dia
• Calcitriol ev - Calcijex 1-2 mcg/sessão
• Colecalciferol (D3) – 0,5 mg/mL
• Paricalcitol oral 1-2 mcg/dia ou 2-4 mcg/dias alternados
• Paricalcitol EV 5 mcg/mL freq máxima dias alternados (HD)
• Ergocalciferol (D2)
• Hipocalcémia severa e sintomática requer tratamento urgente
• Sintomas na urgência: tetania (latente), papiledema, convulsões
• Ansiedade, status confusional agudo, depressão, alucinações, psicose franca
• Prolongamento no intervalo QT no ECG
HIPOCALCÉMIA
• Paresthesias, usually of the fingers, toes, and circumoral regions, and is caused
by increased neuromuscular irritability
• Chvostek's sign
• Trousseau's sign
• Seizures, carpopedal spasm,
• Bronchospasm, laryngospasm,
• Prolongation of the QT interval.
Hipocalcemia
• Falsa hipocalcemia…. Avaliar Cálcio ionizado e albuminemia
• Procurar causas: hipomagnesiemia, pancreatite, sepsis, DRC, LRA;
hipoparatiroidismo, deficiência em Vit D; infusões de citrato, fostato ou albumina.
Toma de fósforo ou bifosfonatos ou calcitonina, rabdomiólise, síndrome de necrose
tumoral, sd malabsorção, terapia anti convulsivante
Tratamento hipocalcemia
HIPOCALCÉMIA
• TREATMENT
– calcium gluconate, 10 mL 10% wt/vol (90 mg or 2.2 mmol)
intravenously
– calcium supplements (1000–1500 mg/d elemental calcium in
divided doses)
– vitamin D2 or D3 (25,000–100,000 U daily) or calcitriol
[1,25(OH)2D, 0.25–2 g/d]
HIPERCALCÉMIA
• Excess PTH production
– Parathyroid adenomas, hyperplasia, or, rarely, carcinoma
• Calcium mobilization from bone
– Hyperthyroidism or osteolytic metastases
• Calcium overload
HIPERCALCÉMIA
Clinical Features
• Mild hypercalcemia (up to 11–11.5 mg/dL)
• Neuropsychiatric symptoms
– Trouble concentrating, personality changes, or depression
• Nephrolithiasis, and fracture risk may be increased
• Severe hypercalcemia (>12–13 mg/dL)
• Lethargy, stupor, or coma, as well as gastrointestinal symptoms
– nausea, anorexia, constipation, or pancreatitis
• Polyuria and polydipsia
HIPERCALCÉMIA
Diagnostic
•
Corrected calcium concentration is calculated by
– adding 0.8 mg/dL to the total calcium level for every decrement in serum albumin of 1.0 g/dL below the reference value of 4.1 g/dL for albumin
•
PTH level using a two-site assay
•
Serum creatinine
Tratamento de hipercalcemia sintomática
Treatment of symptomatic hypercalcemia
•
Volume expansion
•
Loop diuretics
•
Drugs that inhibit bone resorption
– as in malignancy or severe hyperparathyroidism
– bisphosphonates have replaced calcitonin or plicamycin
•
Dialysis may be necessary
•
Intravenous phosphate
– calcium-phosphate complexes may deposit in tissues
– In patients with 1,25(OH)2D-mediated hypercalcemia,
Tratamento hipercalcemia
• Patients with asymptomatic or mildly symptomatic hypercalcemia (calcium <12 mg/dL [3 mmol/L]) do not require immediate treatment. However, they should be advised to avoid factors that can aggravate hypercalcemia, including thiazide diuretic and lithiumcarbonate therapy, volume depletion, prolonged bed rest or inactivity, and a high calcium diet (>1000 mg/day)
● Asymptomatic or mildly symptomatic individuals with chronic moderate hypercalcemia (calcium between 12 and 14 mg/dL [3 to 3.5 mmol/L]) may not require immediate therapy. However, an acute rise to these levels may cause gastrointestinal side effects and changes in sensorium, which requires treatment as described for severe hypercalcemia.
● Patients with more severe (calcium >14 mg/dL [3.5 mmol/L]) or symptomatic hypercalcemia are usually dehydrated and require saline hydration as initial therapy. A reasonable regimen is the administration of isotonic saline at an initial rate of 200 to 300 mL/hour that is then
adjusted to maintain the urine output at 100 to 150 mL/hour.
● In patients with hypercalcemia receiving saline hydration, we suggest not routinely using a loop diuretic (Grade 2C). However, in individuals with renal insufficiency or heart failure, careful monitoring and judicious use of loop diuretics may be required to prevent fluid overload.
