Hiperkalemia postoperatoria en síndrome de hueso hambriento post-paratiroidectomía por hiperparatiroidismo secundario en enfermedad renal crónica terminal / Hyperkalemia-associated hungry bone syndrome post-parathyroidectomy in end-stage denal disease

Introducción: El hiperparatiroidismo secundario (HPTS) es una complicación de la enfermedad renal crónica terminal (ERCT). A pesar de nuevas terapias médicas como calcimiméticos, en HPTS refractarios la paratiroidectomía (PTX) continúa siendo necesaria. Una complicación frecuente en estos pacientes posterior a la PTX es el síndrome de hueso hambriento (SHH), caracterizado por una profunda y prolongada hipocalcemia asociada a hipofosfatemia, secundaria a un excesivo aumento de su captación ósea. Una complicación menos descrita, pero con consecuencias graves e incluso fatales, es la hiperkalemia. El propósito de este trabajo consiste en enfatizar el riesgo de hiperkalemia por SHH a partir de un caso clínico, señalar los mecanismos fisiopatológicos, factores de riesgo y consideraciones terapéuticas. Caso clínico: Mujer de 35 años, con ERCT de causa desconocida, HPTS refractario con PTX total e implante de glándulas en antebrazo hace 9 años. Ingresa por recurrencia de HPTS. Cintigrama MIBI SPECT/CT® evidenció implante hiperfuncionante, indicándose PTX del injerto. Exámenes preoperatorios: calcemia 8.6 mg/dL, fosfatasas alcalinas 1115 UI/L (VN <100), PTH intacta (PTHi) 3509 pg/ml y kalemia 4.8 mEq/L. Biopsia: hiperplasia paratiroidea nodular. En postoperatorio inmediato presentó hiperkalemia de 7.1 mEq/L con cambios electrocardiográficos, requiriendo hemodiálisis de urgencia. Posteriormente desarrolló hipocalcemia, hipofosfatemia e hipomagnesemia, de difícil control. Discusión: El SHH post HPTS puede coexistir con hiperkalemia postoperatoria inmediata grave, incluso fatal si no se identifica y corrige a tiempo. El mecanismo fisiopatológico aún no está bien dilucidado. Varios factores pudieran intervenir, incluyendo aumento del metabolismo celular, traumatismo tisular, fármacos anestésicos, fluidos perioperatorios y flujo de iones transmembrana. El nivel de potasio previo a la cirugía, menor edad, género masculino, tiempo entre la última hemodiálisis y la cirugía, y duración de la PTX, son factores de riesgo para hiperkalemia postoperatoria. El conocimiento de esta grave complicación permitirá estar preparado para monitorizar y eventualmente tratar.

Introduction: Secondary Hyperparathyroidism (SHPT) is a complication of End-Stage Renal Disease (ESRD). Although new medical therapies (i.e.calcimimetics,) parathyroidectomy (PTX) continues to be necessary in refractory cases. A well-known complication after PTX is an entity called Hungry Bone Syndrome (HBS), characterized by deep and prolonged hypocalcemia associated with hypophosphatemia, secondary to an excessive increase in bone formation. A less reported complication, but with severe or even fatal consequences, is hyperkalemia. The purpose of this work consists of emphasizing the risk of hyperkalemia in HBS, reporting a clinical case that points out the physiopathological mechanisms, risk factors, and therapeutic considerations. Clinical case: 35-year-old woman with ESRD of unknown cause with refractory SHPT with total PTX and forearm gland grafts nine years ago. She presented SHPT recurrency. MIBI SPECT/CT® scan showed a hyperfunctioning implant, indicating graft PTX. Preoperative tests: calcemia 8.6 mg/dL, phosphatemia 7.3 mg/dL, alkaline phosphatases 1115 UI/L (VN<100), intact PTH (iPTH) 3509 pg/ml and kalemia 4.8 mEq/L. Biopsy: parathyroid nodular hyperplasia. In the immediate postoperative period, she presented hyperkalemia at 7.1 mEq/L with electrocardiographic changes, requiring emergency hemodialysis. Later she developed hypocalcemia, hypophosphatemia, and hypomagnesemia of difficult control. Discussion: HBS post PTX can coexist with severe immediate postoperative hyperkalemia, which can be even fatal if not detected and corrected. The physiopathological mechanism is still not entirely elucidated. Various factors could interfere, including an increase in cell metabolism, tissue traumatism, anesthetic drugs, intraoperative fluids, and transmembrane ion flow. Preoperative potassium levels, younger age, male gender, the time elapsed between last hemodialysis and surgery, and duration of PTX are risk factors for post-surgical hyperkalemia. Knowing this severe complication will allow the medical team to be prepared for monitoring and eventually treating it.

Tratamiento quirúrgico del hiperparatiroidismo asociado a insuficiencia renal crónica: Experience in 71 patients / Surgical treatment of renal hyperparathyroidism

Background: Surgery is an effective method for the management of renal hyperparathyroidism. Aim: To report the clinical presentation and results of surgical treatment of renal hyperparathyroidism. Material and Methods: Retrospective analysis of 58 patients aged 46 ± 11 years with secondary hyperparathyroidism (HPT2) and 13 patients aged 53 ± 11 years with tertiary hyperparathyroidism (HPT3), operated at a clinical hospital. Results: In 55 cases (77.4%) the indications for surgery were complications of excess parathyroid hormone (PTH) and in 16 patients (22.6%) a failure of medical treatment. Total parathyroidectomy with intraoperative measurement of PTH (PTHop) plus a forearm parathyroid autograft was performed in 54 (93.1%) patients with HPT2 and in all patients with HPT3. PTHop decreased ≥ 75% in 51 patients (88%) with HPT2 and in 9 patients (69.2%) with HPT3, respectively. Cure of the disease was achieved in 52 (89.7%) and 11 (84.6%) patients with HPT2 and 3, respectively. Median follow-up was 41 months. Five (9.6%) patients with HPT2 and two patients (18.2%) with HPT3 had a recurrence of the disease. Conclusions: In patients with renal hyperparathyroidism, the primary indication for surgery was the presence of complications of PTH excess. A drop in PTHop ≥ 75% from baseline predicts healing in 98% and 100% of cases with secondary or tertiary HPT respectively. Surgery was a safe and effective treatment in both groups.

Alteraciones del metabolismo óseo y mineral en enfermedad renal crónica pre-diálisis / Disturbance in mineral and bone metabolism in chronic kidney disease

Las alteraciones del metabolismo mineral y óseo se inician tempranamente en el desarrollo de la enfermedad renal crónica (ERC), aunque las modificaciones en los niveles séricos de calcio y fósforo sólo se pueden apreciar en las etapas finales de la ERC debido a los mecanismos adaptativos que ocurren inicialmente. Con la pérdida de función renal ocurre retención de fósforo, lo que estimula la producción del factor de crecimiento fibroblástico 23 (FGF-23) por el hueso...

Disturbances in mineral and bone metabolism are highly prevalent among chronic kidney disease (CKD) patients and occur early in the development of the disease. However, hyperphosphatemia and hypocalcemia will be present only in the late stage as consequence of adaptative mechanisms. Recent studies indicate that in early CKD, the phosphate retention induces the production of the phosphaturichormone fibroblast growth factor 23 (FGF-23)...

Dermopatía fibrosante nefrogénica: Reporte de dos casos / Nephrogenic fibrosing dermopathy: Report of two cases

Nephrogenic fibrosing dermopathy is a recent designation to describe cutaneous findings in patients with renal disease who developed scleromyxedema-like skin lesions with thickening and hardening of the skin. These skin lesions appear mainly after hemodialysis or renal transplantation but their origin is still unknown. We report a 63 years old male on hemodialysis and 56 years old male on peritoneal dialysis, who developed a nephrogenic fibrosing dermopathy that was confirmed by pathology and immunohistochemistry with monoclonal antibodies against CD34).

La osteodistrofia renal y la paratohormona supresora de la remodelación ósea / Renal osteodystrophy and supressor paratohormone in bone remodeling

El Hiperparatiroidismo juega un rol central en la Osteodistrofia Renal (ODR) en pacientes con Insuficiencia Renal Crónica (IRC). Las primeras determinaciones de paratohormona (PTH) sérica aplicadas a la clínica en los años 1960, se basaban en métodos de radioinmunoanálisis (RIA) que usaban un solo anticuerpo contra la región carboxiterminal o la región media de la hormona. En 1987 se introdujo un método inmunométrico (IMA) basado en 2 anticuerpos, denominada en sandwich o PTH intacta, rutinariamente usado hasta hoy en la Investigación y Guías de manejo de la Osteodistrofia. A fines de la década del 90, autores detectaron 2 picks inmunoreactivos al usar el método tradicional, uno de ellos comigraba con la PTH intacta 1-84, en tanto que el 2º pick comigraba con la fracción 7-84, sugiriendo que un importante fragmento inactivo era incluido en las mediciones IMA, sobreestimando el real valor de la PTH, y exponiendo al paciente a tratamientos con altas dosis de vitamina D activa. Este método permitió separar la fracción biológicamente activa, denominada CAP-PTH, de una fracción supresora del metabolismo óseo, la CIP-PTH, y ha sido asociado a la falta de correlación entre la histomorfometría ósea y la PTH intacta 1-84. El importante aumento de la forma adinámica de ODR y las calcificaciones vasculares en los adultos urémicos, se han relacionado a elevadas dosis de vitamina D, calcio y fósforo, terapias que hasta hoy eran orientadas por los niveles de PTH plasmática. El actual manejo de la ODR debe ser reevaluado a la luz del conocimiento actual, y de futuras investigaciones que permitirán un mejor control de esta complicación de la Insuficiencia Renal Crónica.

Tratamiento exitoso de abscesos cerebrales múltiples por nocardia en paciente sometido a transplante renal / Successful therapy of nocardial multiple brain abscesses in a renal transplant recipient

Se presenta un caso de abscesos cerebrales múltiples en un paciente sometido a transplante renal. El drenaje quirúrgico combinado con una terapia antimicrobiana prolongada fueron exitosos y el paciente está actualmente en buenas condiciones, sin secuelas neurológicas

La anemia de la glomerulonefritis aguda post-estreptocócica / Anemia associated to acute post streptococcal glomerulonephritis

Thirty-three children with post-streptococcal acute glomerulonephritis, age x:8.3 years (range 6-12) were studied prospectively. Mean initial hematocrit (Hct) was 31.6 percent with 90 percent showing Hct under the normal lower limit for this age group. Reticulocyte index (RI) was <0.5 in half of the cases. Serum iron concentration, total iron binding capacity (TIBC) and percentaje of transferrin saturation were normal for this age group although 75 percent of the children had increased serum ferritin levels. At the time of discharge, Hct increased to 35.1 percent but 44 percent still had anemia. Hct increased spontaneously for 105 days stabilizing at 38 percent. Based on Hct changes, 3 groups were defined: Group I (3 individuals): normal upon discharge; Group II (19): partial recovery at discharge, slow recovery stabilizing after 105 days; Group III (11): lower Hct, slower recovery but with RI significantly higher than group II (0.96 vs 0.45 p<0.01). Our data suggest that although hemodilution is present in all, it may be considered the solely factor only in 3 cases (Group I). In group II, evidence of bone marrow depression was indicated by the low RI. On the other hand, the intense anemia that could not be justified only by hemodilution and marrow depression in group II, suggest other pathogenic factors

Nefropatía por IgA (enfermedad de Berger): experiencia en 78 casos / Ig-A nephropathy

We studied 78 patients with a diagnosis of IgA nephropathy. Renal biopsy was indicated in 69 patients by the presence of macroscopic hematuria (52%), microhematuria or renal failure (14%) or hephritic syndrome (1%). Nine were healthy subjects being studied as live kidney donors. An association with IgG and/or IgM was present in 92% of patients. Serum IgA was elevated in 36% of patients. Hypertension was present in 30% and decreased renal function in 29%. Patients with serum creatinine above 1,5 mg/dl tended to be older (33.8 vs 28.7 years) and to have hypertension (52% vs 19%). among 25 pátients followed for more than 12 months renal function remained stable in 44%, deteriorated in 20% and 36% developed renal failure. the latter was associated to older age, hypertension, abscense of macroscopic hematuria and nephrotic syndrome. The 9 live donors had no clinical manifestations of renal disease. Thus, IgA nephropathy is a highly variable clinical manifestations and its prognosis. An asymptomatic course is demonstrated in some subjects