Heart rate variability in advanced chronic kidney disease with or without diabetes: midterm effects of the initiation of chronic haemodialysis therapy.

BACKGROUND: Previous studies in different clinical settings have established heart rate variability (HRV) as a significant independent risk factor for higher mortality and cardiac death. The aim of this study was to examine the effect of chronic haemodialysis therapy on time- and frequency-domain parameters of HRV in diabetic and non-diabetic patients with chronic kidney disease (CKD). METHODS: We studied 25 patients with stage 4 CKD and type 2 diabetes mellitus (CKD4+DM), 25 patients with stage 4 CKD without diabetes (CKD4), 25 patients with type 2 diabetes mellitus (DM) and 25 healthy subjects (HS). The study was performed in two phases. In the first phase, a 24-h Holter electrocardiographic (ECG) monitoring was performed in all subjects. The patients with stage 4 CKD were followed up until they progressed to stage 5, and in the second phase of the study, they underwent a 24-h Holter ECG monitoring after completion of 3 months of conventional haemodialysis treatment. RESULTS: In the first phase of the study, a reduction in cardiac sympathetic activity in CKD4 patients (significantly lower SDNN, SDANN/5 min, SD and VLF vs. HS) and worse autonomic function in CKD4+DM patients (significantly lower SDNN, SDANN/5 min, SD, VLF and LF/HF) vs. HS, DM and CKD4 was observed. After 3 months of dialysis therapy, the patients with CKD+DM showed a significant improvement only in the time-domain parameter SDANN/5 min, while the time-domain parameters SDNN, SDANN/5 min and SD were improved in CKD patients without diabetes. Frequency-domain parameters of HRV remained unchanged in both groups. CONCLUSIONS: CKD is associated with worse cardiac autonomic function. Haemodialysis therapy for 3 months improves some indices of HRV, and this effect is more pronounced in non-diabetic subjects. Our findings suggest that the improvement of HRV after the initiation of chronic dialysis therapy can ameliorate clinical outcomes and survival in patients with end-stage renal disease.

Pseudohyperkalemia in serum: a new insight into an old phenomenon.

Pseudohyperkalemia, a rise in serum potassium concentration with concurrently normal plasma potassium concentration, is an in vitro phenomenon that was first described 50 years ago. It was originally attributed to the release of potassium from platelets during platelet aggregation and degranulation, and a significant correlation between pseudohyperkalemia and platelet count was established. During the last decade, new data were added to this phenomenon. In particular, pseudohyperkalemia was defined when serum potassium concentration exceeded that of plasma by more than 0.4 mmol/L provided that samples are collected under strict techniques, remain at room temperature and are tested within 1 hour from blood specimen collection. Moreover, it is positively correlated to (1) thrombocytosis due to the release of potassium from platelet granules during coagulation, (2) erythrocytosis due to the dilution of the released potassium in smaller volumes of serum, and (3) the presence of activated platelets, which have the capability of aggregation at a higher speed and release more potassium during degranulation. However, pseudohyperkalemia may be "masked" when in a state of hypokalemia because potassium moves back into the intracellular space in vitro, and the phenomenon is ameliorated or even not detected.

Changes of liver and muscle enzymes activity in patients with rigor.

AIM: We investigated whether changes of liver and muscle enzymes activity are associated with rigor of several causes and have any prognostic significance. METHODS: Seventy-five patients with rigor were prospectively evaluated. Serum enzymes were measured at the onset of rigor and during the three following days. RESULTS: Causes of rigor were bacteremia (n=28), cholangiitis (n=12), protozoan infections (n=9), viral infections (n=10) and platelet transfusions (n=16). Increases in enzymes activity were observed with rigors from infectious causes, but not with that following platelet transfusions. Patients with cholangiitis demonstrated the highest ALT elevations, while those with viral infections the highest CPK levels. In bacteremia, CPK values increased significantly only in cases with dehydration and hypokalemia. CONCLUSIONS: Rigor per se does not cause increases in muscle or liver enzymes activities. Rather these changes are associated with the rigor's causative agent (infectious or not), the patient's general condition and the severity and extent of the underlying disease.

Liver involvement in acute vaso-occlusive crisis of sickle cell disease: prevalence and predisposing factors.

OBJECTIVE: To study the prevalence and predisposing factors of liver involvement in sickle cell disease (SCD) of patients with acute vaso-occlusive crisis. MATERIAL AND METHODS: We prospectively evaluated 41 consecutive patients (44% M, median age 39 years, range 16-56 years) with homozygous (HbSS; 12 cases) or sickle cell-beta thalassemia (HbSbeta-thal; 29 cases), admitted to our Medical Department in the period 2002 to 2004. Severity of crisis was graded by in-house-modified APACHE score; presence of asplenia or functional hyposplenism was also considered. Hematological and biochemical parameters including various relevant enzymes/isoenzymes were followed daily. RESULTS: Despite the fact that only 9 patients (22%) presented with acute painful hepatomegaly, liver involvement was evident in 16 (39%); hepatocellular-type injury was found in 1 patient, cholestatic in 8, and mixed in 7. Severity of crisis was not related to liver involvement (score 20.6 versus 18.2), but liver involvement occurred in the presence of normal spleen function (p<0.001) and platelet counts <500,000/mm(3) (p<0.001) were. Patients with liver involvement, compared with those without, had higher total and direct bilirubin levels (4.3 versus 2.9 mg/dL, p=0.050; 1.9 versus 0.8 mg/dL, p=0.010, respectively), lower hematocrit (19% versus 23%, p=0.030) and longer hospitalization (10 versus 6.3 days, p<0.001). CONCLUSIONS: In SCD, there is a 39% prevalence of acute veno-occlusive involvement of the liver, a figure that is much higher than previously reported. The type of injury is mostly mixed hepatocellular-cholestatic or purely cholestatic and its course is usually benign. Liver involvement occurs more often in patients with normal spleen function and is not associated with the overall severity of the acute episode, both observations being unreported previously.

Myelodysplastic syndrome presenting as acquired ichthyosis.

Ichthyosis is a cutaneous keratinization disorder that can either be congenital or acquired. Acquired ichthyosis has been reported in association with a variety of neoplastic, autoimmune, and infectious diseases. We report the case of a 68-year-old woman who presented with generalized ichthyosis as the first manifestation of myelodysplastic syndrome. This is the first fully described case of such an association in the English literature.

Pseudohyperkalemia in serum: the phenomenon and its clinical magnitude.

We investigated in detail the difference between serum and plasma potassium levels in patients with several conditions associated with pseudohyperkalemia. In total, 435 patients with either thrombocytoses, erythrocytoses, leucocytoses, or a mixed-type disorder and 30 healthy controls were included. In each case, the index Dk [serum potassium minus plasma potassium] and the index Dk100 (Dk x 100,000/platelets), which indicates the Dk value that corresponds to platelets of 100,000/mm(3), were estimated. Median Dk was significantly higher in the groups with platelet, erythrocyte, or mixed-type disorders than in the controls (P=0.001). Among these groups, Dk values were significantly higher in patients with thrombocytosis or mixed-type disorders compared with those with erythrocytosis (P<0.001, for both). Furthermore, no significant difference was observed in Dk values between controls and patients with white blood cell disorders (P=0.74). Dk values did not exceed 2.61 mmol/L, whereas Dk100 values were inversely related to platelet counts (r=-0.351, P<0.01). In conclusion, pseudohyperkalemia is mainly present in patients with thrombocytosis or mixed-type disorders, probably as a result of the degranulation of platelets, which offers a potassium load to the surrounding plasma at the time of clot formation in vitro. However, the degree of pseudohyperkalemia does not increase proportionally with the increase of platelet counts, which may be associated with transfer of part of potassium load from the plasma back into red and white blood cells.

Pseudohyperkalemia in patients with increased cellular components of blood.

OBJECTIVE: We performed a study to investigate the difference between serum and plasma potassium concentration in patients with increase in one or more of the cellular components of blood. DESIGN AND METHODS: This study was performed in two phases. During the first phase, we performed a cross-sectional comparison of the difference between serum and plasma potassium concentration (Dk) in 341 patients with the various clinical conditions where pseudohyperkalemia has been described, as well as with secondary or spurious erythrocytosis and in 30 normal controls. A cut-off value of Dk discriminating polycythemia vera from other erythrocytoses was estimated. In the second phase we studied the significance of this cut-off value as predictor of polycythemia vera in 90 naive patients who were referred with an elevated hematocrit. RESULTS: Dk was significantly increased in the groups with platelet, erythrocyte or with a mixed type disorder compared to the controls (P < 0.01). Among these groups, Dk was significantly increased in the groups with thrombocytosis and mixed type disorder, compared to the group with erythrocytosis (both P < 0.01). A cut-off value of Dk discriminating polycythemia vera from other erythrocytoses was estimated (0.70 mmol/L). Dk (> or = 0.70 mmol/L), platelet and white blood cell count were identified as significant independent predictors of polycythemia vera. CONCLUSIONS: The Dk is increased in patients with erythrocytoses, thrombocytoses or both. This phenomenon is more profound in patients with a mixed type disorder, such as polycythemia vera patients, compared to those with erythrocytoses alone.

Cholestasis in acute stroke: an investigation on its prevalence and etiology.

OBJECTIVE: Liver cholestatic enzymes and/or bilirubin occasionally occur in acute stroke and are usually, but not always, ascribed to comorbid conditions. We investigated the frequency and possible etiology of this phenomenon. MATERIAL AND METHODS: Prospective evaluation of post-admission biochemical cholestasis of all patients hospitalized with acute stroke was conducted during a 21-month period. RESULTS: Of 169 consecutive patients, 18 (10.7%) developed cholestasis. In 7 of the patients (4.1%; 4 M, 3 F, median age 70 years, range 57-82 years) no apparent cause of cholestasis could be found, and they were further evaluated (Group A). These patients were compared with 21 randomly selected stroke patients without cholestasis, matched for age and gender, and who acted as controls (Group B). Group A patients were in a deeper coma than the controls (Glasgow Coma Scale 3.4 +/- 0.8 versus 1.9 +/- 0.7, p < 0.001), associated with severe autonomic and hypothalamic involvement, while no such manifestations were present in Group B (p < 0.001). Cholestasis started on the 3rd-6th day and lasted up to the 11th-25th day, with maximum median levels of gamma-GT and serum alkaline phosphatase (SAP) of up to 4.38 (range 2.33-8.25) and 1.49 (range 0.63-2.56) times the upper limit of normal, respectively. Serum alanine aminotransferase (ALAT), total and direct bilirubin increased in Group A but not in Group B. The common bile duct was significantly wider in Group A than in Group B (7.7 +/- 0.5 versus 4.7 +/- 0.6 mm, p < 0.001) and within Group A during and after cholestasis (7.7 +/- 0.5 versus 4.7 +/- 0.5 mm, p < 0.001). CONCLUSIONS: Transient cholestasis may occur in 4.1% of patients following acute stroke. Cholestasis is associated with deeper coma, autonomic and hypothalamic involvement and common bile duct dilatation without obstruction, possibly related to inordinate hypertonia of the sphincter of Oddi.

Occidental beriberi and sudden death.

Beriberi, thiamine deficiency, is classified as "dry" (neurologic) or "wet" (cardiovascular) and may be mixed. Deficiency of this vitamin may be nutritional or secondary to alcohol intoxication. In Western societies (occidental beriberi), the disorder is more commonly observed in long-term alcohol abusers. However, it may go undiagnosed because it is relatively uncommon. In some cases (acute cardiovascular beriberi), early treatment with parenteral vitamin B1 is required to prevent the development of low-output state and sudden death. We report a case of occidental beriberi with fatal outcome despite therapy.

Primary aortojejunal fistula due to foreign body: a rare cause of gastrointestinal bleeding.

Primary and secondary aortoenteric fistulae are infrequent causes of gastrointestinal bleeding. We report a rare case of a 49-year-old man with bleeding due to an aortojejunal fistula caused by a foreign body. This is the fifth case in the literature in which a foreign body was found to be associated with the development of an aortoenteric fistula. Our patient presented with two herald bleeds with an interval time of 1 week; in previous cases, only one herald bleed has been reported. In addition to the usual resuscitation measures, the patient was treated with primary repair of the small-intestine defect and replacement of the aneurysm with a prosthetic aortic graft. He remains in excellent health thereafter.