Syncope: a rare presentation of massive pulmonary embolism in a previously healthy girl.

Pulmonary embolism is a very infrequent event in previously healthy children, particularly in the outpatient scenario. This report involves a 7-year-old girl who presented to the emergency room after syncope. A prompt diagnostic workup showed a massive pulmonary embolism. A timely treatment initiation permitted a good and rapid response. She represented a diagnostic and treatment challenge, mainly because of the atypical presentation and the absence of known risk factors. Finally, a thorough study uncovered a nephrotic-range urine protein loss. At the beginning, the patient did not meet the whole nephrotic syndrome diagnostic requirements. The complete thombophilic study was normal. The clinical presentation, epidemiology, diagnostic tools and the treatment of pulmonary embolism are reviewed. We also discuss a recently described risk factor, present in our patient, as a potential role in the development of pulmonary embolism.

Decreased nitric oxide products in the urine of patients undergoing cardiac surgery.

OBJECTIVE: Renal vasoconstriction has been blamed as a cause of perioperative renal dysfunction after cardiac surgery. Endothelial function is a critical determinant of vascular tonus, including vasoconstriction. The objective of this study was to establish whether the release of the endothelial vasodilator nitric oxide (NO) or NO products is altered in patients undergoing surgery with cardiopulmonary bypass in 3 different clinical conditions. DESIGN: Observational and randomized prospective study. SETTING: University hospital. PARTICIPANTS: Adults and pediatric patients undergoing elective cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Three groups of patients were studied: group 1, 10 patients undergoing elective coronary artery surgery; group 2, 20 patients undergoing elective coronary artery surgery randomized to 2 hematocrit values during cardiopulmonary bypass, high (27%) and low (23%); and group 3, 10 pediatric patients undergoing surgical repair of noncyanotic cardiac defects. MEASUREMENTS AND MAIN RESULTS: NO products (NO2 + NO3) and cyclic guanosine monophosphate (cGMP) in urine were measured before, during hypo- and normothermic cardiopulmonary bypass, and 1 hour postoperatively. Filtration fraction was calculated. The glomerular filtration rate and effective renal plasma flow were measured with inulin and (131)I-hippuran clearances, respectively. Urinary alpha glutathione s-transferase was measured pre- and postoperatively in groups 1 and 3. NO products, as well as cGMP, decreased significantly during hypo- and normothermic cardiopulmonary bypass in all groups. This was not because of urine dilution or the degree of hemodilution. Age did not appear to alter this response. Filtration fraction decreased during cardiopulmonary bypass. Alpha glutathione s-transferase was normal pre-and postoperatively. CONCLUSIONS: Cardiac surgery with cardiopulmonary bypass is associated with a significant decrease of NO products. In the absence of kidney damage, decreased NO products could represent a physiologic response to cardiopulmonary bypass; however, endothelial dysfunction cannot be excluded.

Renal function and cardiopulmonary bypass in pediatric cardiac surgical patients.

We studied prospectively the perioperative changes of renal function in nine children undergoing cardiac surgery with cardiopulmonary bypass (CPB). Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured with inulin and (131)I-hippuran clearances before CPB, during hypo and normothermic CPB, following sternal closure and 1 h postoperatively. Urinary alpha glutathione S-transferase (alpha GS-T) was measured pre- and postoperatively as a marker for tubular cellular damage. Plasma and urine creatinine and electrolytes were measured. Free water, osmolal and creatinine clearances, as well as fractional excretion of sodium (FeNa) and potassium transtubular gradient (TTKG) were calculated. GFR was normal before and after surgery. ERPF was low before and after surgery; it increased significantly immediately after CPB. Filtration fraction (FF) was abnormally elevated before and after surgery; however, a significant decrease during normothermic CPB and sternal closure was found. Alpha GS-T presented a moderate, but nonsignificant increase postoperatively. FeNa also increased in this period, but not significantly. Creatinine, osmolal, free water clearances, as well as TTKG, were normal in all patients pre- and postoperatively. We conclude that there is no evidence of clinically significant deterioration of renal function in children undergoing repair of cardiac lesions under CPB. Minor increases of alpha GS-T in urine postoperatively did not confirm cellular tubular damage. There was no tubular dysfunction at that time.

[Hemolytic uremic syndrome: the experience of a pediatric center]. / Síndrome hemolítico urémico: experiencia de un centro pediátrico.

BACKGROUND: Hemolytic uremic syndrome (HUS) is one of the main causes of acute renal failure in the Chilean pediatric population. AIM: To report the features of patients with HUS, admitted to the pediatric ward of a clinical hospital. MATERIAL AND METHODS: Retrospective review of medical records of patients admitted with the diagnosis of HUS between 1995 and 2002. RESULTS: During the period, 58 patients were admitted with the diagnosis of HUS but only 43 (age range 1 month to 6 years, 22 females) had complete medical records for review. Ninety five percent presented with prodromic diarrhea, mainly dysenteric. Antibiotics were administered to 70%, in the previous days. Acute renal replacement, mainly peritoneal dialysis, was required in 40%. The clinical signs and laboratory parameters that correlated better with the indication for dialysis were anuria, hypertension, initial and permanently high serum creatinine and blood urea nitrogen. Four patients with blood urea nitrogen over 100 mg/dl but without anuria or hyperkalemia, were treated conservatively, and experienced an uneventful course (permissive azotemia). Hospital stay was almost 3 times greater in dialyzed than in non dialyzed children. No deaths related to HUS were reported in the study period. In an average follow up of 54 months, 11.6% of the patients developed chronic renal failure of diverse magnitude. CONCLUSIONS: Despite the fact that our study group behaved clinically similar to published HUS patients in other series, no mortality was observed in a retrospective analysis of patients with this disease.

[Continuous hemofiltration in patients with abdominal complications of hemolytic uremic syndrome]. / Hemofiltración continua en pacientes con complicaciones abdominales del síndrome hemolítico urémico.

BACKGROUND: Close to one half of patients with hemolytic uremic syndrome (HUS) will require a dialytic therapy, mainly peritoneal dialysis (PD). In some cases, PD may have relative or absolute contraindications, usually when HUS is associated to severe intraabdominal complications. AIM: To report the results of continuous hemofiltration use, in children with abdominal complications of HUS. MATERIAL AND METHODS: Retrospective review of the files of 40 patients that were admitted to our pediatric unit with HUS, since 1995. Six children had relevant intra-abdominal complications and were treated with continuous hemofiltration (CHF). Four additional children, with similar HUS related complications and treated with CHF before 1995, were included in the analysis. RESULTS: The age of the patients ranged from 5 to 66 months old. An arterio-venous CHF was performed in four and veno-venous CHF in six children. The duration of CHF was 93.2 hours in average. Adequate control of volemia was achieved in every patient; diafiltration with peritoneal dialysis solution was added in five patients, to improve azotemia. Four patients had complications related to the vascular access or the anticoagulation procedure. The procedure was terminated due to improvement of diuresis in five cases, transfer to PD in four and a cardiorespiratory arrest in one. Only one patient developed a chronic renal failure during the follow up. CONCLUSIONS: CHF is an effective and safe alternative of acute renal replacement therapy in the management of renal failure in pediatric cases with HUS, aggravated with abdominal complications.