贝那普利和氯沙坦对血液透析患者血钾的影响

目的探讨维持性血液透析(maintenance hemodialysis,MHD)患者单独或联合应用贝那普利和氯沙坦对血钾的影响。方法 44例MHD患者为研究对象,透析前血钾6.0mmol/L。随机分为A、B两组,于观察起始及1月后A组患者依次加用贝那普利(10mg qd)和氯沙坦(50mg qd),B组患者依次加用氯沙坦和贝那普利,其他用药不变,观察3个月。检测用药前、用药后1个月、2个月、3个月的透析前血钾水平,用药前和用药后3个月清晨透析前平卧位血清醛固酮水平。应用独立样本t检验,方差分析和x2方检验分析相关结果。结果用药前、单独应用贝那普利或氯沙坦以及联合应用贝那普利和氯沙坦血钾水平及高钾血症发生率差异无统计学意义(P0.05);用药后患者血清醛固酮水平较用药前明显下降(P=0.016)。结论 MHD患者单独或联合应用贝那普利及氯沙坦对血钾水平及高钾血症的发生率无显著影响。     

Total-body potassium in insulin-dependent diabetes mellitus

1. Total-body potassium and fat-free mass have been measured in 31 insulin-dependent diabetic patients and 31 age- and sex-matched normal volunteers. 2. Body mass index was significantly higher in the insulin-dependent diabetic patients (24.7 +/- 0.5 vs 23.3 +/- 0.4 kg/m2; P = 0.05). 3. Total-body potassium, uncorrected and corrected for weight and for fat-free mass, was not significantly different in the two groups (3281 +/- 141 mmol, 47.3 +/- 1.3 mmol/kg body weight, 60.9 +/- 1.0 mmol/kg fat-free mass, and 3315 +/- 143 mmol, 48.6 +/- 1.0 mmol/kg body weight, 60.4 +/- 0.8 mmol/kg fat-free mass, respectively, in diabetic patients and non-diabetic subjects). There was no relationship between blood glucose control, as assessed by glycated haemoglobin concentrations, and total-body potassium. 4. These results suggest, by contrast with previous reports, that in insulin-dependent diabetic patients, showing varying degrees of glycaemic control (glycated haemoglobin range 6.1-15.3%, mean 9.0%) that: (a) there is no significant abnormality of body potassium homoeostasis, and (b) there is no relation between total-body potassium and glycaemic control.     

Serum potassium levels during prolonged hypothermia

Hypokalemia (mean serum potassium 2.3 +/- 0.4 mEq/l) was observed in six hypothermic patients (30 degrees - 32 degrees C) with head injuries or brain hypoxia. In the first three patients, potassium was administered to maintain serum levels above 3.5 mEq/l and on rewarming after 48 h of hypothermia hyperkalemia (peak serum potassium = 7.1 +/- 0.5 mEq/l) associated with cardiac arrhythmias developed. The remaining three patients received sufficient potassium to approximately replace measured losses during the hypothermic period. These patients did not become hyperkalemic on rewarming. Clinically insignificant sinus bradycardia, premature atrial contractions and junctional rhythms were seen during hypothermia with hypokalemia. We conclude that hypothermia produces hypokalemia by a shift of potassium from the extracellular to intracellular or extra vascular spaces. Potassium therapy during controlled hypothermia in the range 30 degrees - 32 degrees C should only replace measured losses.     

The effect of parenteral feeding on the metabolism of arachidonic acid in patients with cancer of the esophagus and the stomach

Blood plasma and erythrocyte level of arachidonic acid (C20:4) and blood plasma level of its two metabolites (6-keto-PGF1 alpha and TXB2) have been investigated in 24 patients with esophageal and gastric cancer. In the preoperative period and during 8-10 days postoperatively 12 patients were on "glucose" energy supply (group I) and 12 patients were on "lipid" energy supply (group II). Daily calorie intake was 30-35 kcal/kg. In the preoperative period Lipofundin-S infusions produced a significant increase in C20:4 blood plasma and erythrocyte levels. An increase in TXB2 concentration was accompanied by a certain increase in 6-keto-PGF1 alpha content. At the same time in group I parenteral feeding caused no significant changes in the above parameters. Surgical trauma and anesthesia caused a considerable increase in 6-keto-PGF1 alpha blood plasma level in both groups (P less than 0.05), with a certain decrease in TXB2 level (P greater than 0.05). In the postoperative period, unlike "glucose", "lipid" energy supply stabilized C20:4 content in the erythrocyte membrane and favourably affected 6-keto-PGF1 alpha/TXB2 ratio. This is confirmed by a considerable increase in 6-keto-PGF1 alpha/TXB2 ratio, which in the course of the postoperative period was significantly higher in group II than in group I.     

Basal metabolic rate in adults with growth hormone deficiency and in patients with acromegaly: relationship with lean body mass, plasma insulin level and leucocyte sodium pump activity.

1. The relationship of lean body mass, plasma insulin concentration and leucocyte active sodium transport with basal metabolic rate was investigated in 24 adults with growth hormone deficiency before and after treatment with recombinant human growth hormone and in 10 patients with untreated acromegaly. 2. Based on total-body potassium determined by whole-body 40K counting, patients with acromegaly had increased lean body mass, whereas lack of growth hormone was associated with decreased lean body mass. 3. By indirect calorimetry, patients with acromegaly had increased basal metabolic rates and patients with growth hormone deficiency had decreased values when expressed as percentages of values predicted from the WHO/FAO/UNU equations. Basal metabolic rate expressed in terms of lean body mass was similar in acromegaly and growth hormone deficiency, but was higher than normal in both patient groups. 4. The leucocyte ouabain-sensitive sodium efflux rate constant was decreased in both patients with acromegaly and patients with growth hormone deficiency, and there was no correlation with basal energy expenditure, fasting plasma insulin level or serum growth hormone level. 5. There was no increase in the sodium efflux rate constant in patients with growth hormone deficiency after 1 month on treatment with recombinant human growth hormone. 6. Apparent differences in basal metabolic rate in growth hormone deficiency and acromegaly are due to changes in lean body mass. Both adults with growth hormone deficiency and patients with acromegaly have increased energy expenditure, probably owing to changes in fuel metabolism which are not reflected in the leucocyte sodium pump activity.     

Acute Potassium Dichromate Poisoning: A Toxicokinetic Case Study

Case Report: A 48-year-old man drank 150 mL of an aqueous solution containing potassium dichromate 22.5 g in a suicidal attempt and was admitted 7 hours after the ingestion. Hemodialysis was promptly undertaken and chromium concentrations in serum, erythrocytes, and dialysate were determined during the treatment. Chromium elimination in urine was monitored during hemodialysis and the subsequent 400 hours. The total chromium eliminated via hemodialysis and urine was calculated as 36.7 mg or 0.16% of the ingested dose. Spontaneous urinary elimination proceeded according to an open one-compartment model. The elimination half-life was 71.37 hours ± 17.13 hours (95% CI). Chromium elimination from serum followed an open two-compartment model, with the half-lives of 3.16 hours ± 2.63 hours for phase 1 and 50 hours ± 27 hours (95% CI) for phase 2. Calcium-EDTA therapy had no influence on erythrocyte, serum, or urine chromium level. It contributed, however, to a significant increase in chromium elimination rate in the dialysate. Serum zinc was very low at admission and serum zinc, copper, and magnesium were controlled during the initial 30 hours.     

Reference values of magnesium and potassium in mononuclear cells and erythrocytes of children

Reference values for magnesium and potassium contents of mononuclear cells and erythrocytes were estimated in cord blood and in children from infancy through adolescence. No differences were detected between results for boys and girls. The mononuclear magnesium content was independent of age and was within the adult range of values. No significant correlation was shown between magnesium in serum and in mononuclear cells. Mononuclear potassium also showed no age-related differences. The correlation between magnesium and potassium contents in mononuclear cells was significant: however, the correlation was lower when the magnesium and potassium contents were expressed in terms of protein potent: micromoles or millimoles per gram of protein, respectively. The concentration of magnesium in erythrocytes was significantly lower in cord blood and during the first month of life, compared with that at older ages, and showed no significant correlation with serum magnesium. The concentration of erythrocyte potassium was independent of age and showed a low but significant correlation with erythrocyte magnesium content.     

Effects of additive therapy with spironolactone on proteinuria in diabetic patients already on ACE inhibitor or ARB therapy: results of a randomized, placebo-controlled, double-blind, crossover trial.

INTRODUCTION: Aldosterone seems to have deleterious effects on the kidneys. Many animal studies and a few clinical trials have shown that suppression of aldosteroneby aldosterone receptor blockers ameliorates these effects. METHOD: In a double-blind crossover study, patients with diabetic nephropathy who were already receiving either angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) were given spironolactone or matching placebo with 1 month of washout in between. Blood pressure (BP), serum creatinine, serum potassium, and spot urine protein/creatinine were measured at the beginning and end of each study period. RESULTS: Mean systolic BP on spironolactone went down from 153.64 (+/-25.95) at the beginning to 141.60 (+/-16.54) at the end of study (P = 0.01). Diastolic BP during spironolactone therapy did not change significantly. The urine protein/creatinine increased from 1.24 (+/-1.13) to 1.57 (+/-2.13) on placebo (P = 0.35) and decreased from 1.80 (+/-1.78) to 0.79 (+/-0.99) during spironolactone therapy (P = 0.004). In other words proteinuria increased by 24% during the placebo treatment period but decreased by half (57%) during the active treatment. Serum potassium increased from 4.29 (+/-0.47) to 4.64 (+/-0.55) during spironolactone therapy (P = 0.002), no significant change with placebo. Whereas serum creatinine did not change on placebo, it increased from 1.35 (+/-0.54) to 1.56 (+/-0.62) on spironolactone (P = 0.006). Glomerular filtration rate decreased from 61.91 (+/-23.4) to 53.94 (+/-23.58) on spironolactone (P = 0.0001) but not on placebo. CONCLUSIONS: Addition of a modest dose of spironolactone to a regimen of ACEI or ARB in patients with diabetic proteinuria causes further reduction in proteinuria and also lowers the systolic BP. As with ACEI or ARB, spironolactone modestly reduces the glomerular filtration rate and raises serum potassium.     

Time-level relationship between indicators of oxidative stress and Glasgow Coma Scale scores of severe head injury patients.

BACKGROUND: Oxidative stress is said to strongly influence the neurological recovery of patients following a severe head injury. Estimation of the markers of oxidative stress in the blood of such patients can hence aid in predicting the prognosis of head injury. METHODS: Erythrocyte thiobarbituric acid-reactive substances (TBARS) and plasma ceruloplasmin (CP) levels were estimated in 24 severe head-injury patients on days 1, 7 and 21 of the post-traumatic period and compared with levels in 25 healthy age- and sex-matched controls. These parameters reflecting oxidative stress status were related to the Glasgow Coma Scale (GCS) scores of patients noted at the same time points of the study period. RESULTS: Lipid peroxidation as indicated by increased levels of erythrocyte TBARS remained significantly elevated in severe head injury patients compared to controls on day 1 (p<0.001), day 7 (p<0.001) and 21 (p<0.001) of the post-traumatic period. Plasma CP levels remained significantly elevated (p<0.001) at these three time points compared to controls. The significant decrease in lipid peroxidation products (p<0.01) and significant increase in CP levels (p<0.001) on day 21 compared to day 1 in head injury patients correlated well with the significant improvement in GCS scores of patients on day 21 compared to day 1 (p<0.05). CONCLUSION: The above results could account for the adaptation of the study patients to severe oxidative stress, as evidenced by their clinical recovery trend during the study period.     

慢性阻塞性肺疾病急性加重期患者体液离子含量的变化

目的：了解慢性阻塞性肺疾病（COPD）患者体液离子含量的变化。方法：选择46例合并肺心病的COPD急性加重期患者，测定其血清、红细胞、白细胞及24h尿K、Na、Ca、Mg离子含量。结果：患者自细胞Ca增高，红细胞Ca、Mg、K及白细胞Mg、血清Mg、Na均显著降低。红细胞Mg与白细胞Mg显著正相关。该组患者尿Ca增多占54％，尿K、Na、Mg减低者分别占92％，65％及32％。结论：COPD患者存在K、Mg缺失，用红细胞Mg评价机体的Mg状态更具有实用性。     

Blood pressure lowering and potassium conservation by triamterene-hydrochlorothiazide and amiloride-hydrochlorothiazide in hypertension

Effects of once-daily doses of 50 mg triamterene with 25 mg hydrochlorothiazide and 5 mg amiloride with 50 mg hydrochlorothiazide were compared in a randomized, multicenter study of 84 adult subjects with mild to moderate hypertension (diastolic blood pressure 90 to 114 mm Hg). After a 3-wk placebo lead-in period, the subjects entered a 6-wk treatment period. The two drug regimens were compared with respect to antihypertensive effects and effects on serum potassium and magnesium levels during the final week of drug therapy, with the use of the last week of placebo therapy as a covariate. Both drug regimens substantially reduced mean supine systolic and diastolic blood pressures to well within normal limits; there was no significant difference the two groups. Twenty-four of the 41 subjects receiving triamterene-hydrochlorothiazide (59%) and 29 of the 43 patients receiving amiloride-hydrochlorothiazide (67%) had diastolic blood pressure less than 90 mm Hg at week 9. Five subjects receiving amiloride-hydrochlorothiazide (12%) and two subjects receiving triamterene-hydrochlorothiazide (5%) had hypokalemia (serum potassium level less than 3.5 mEq/l) at week 9. The average decrease in serum potassium levels during amiloride-hydrochlorothiazide therapy (-0.33 +/- 0.08 mEq/l) was greater than that after triamterene-hydrochlorothiazide (- 0.08 +/- 0.07 mEq/l). Serum magnesium levels were not changed by either regimen. Weight loss was greater in the amiloride-hydrochlorothiazide group than in the triamterene-hydrochlorothiazide group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Risk factors for thiazide-induced hyponatraemia

BACKGROUND: Thiazide-induced hyponatraemia is common and potentially life threatening. In the absence of well-defined risk factors for this complication, guidelines for prescribing cannot be established. AIM: To examine whether a subgroup of patients is particularly susceptible to this complication. DESIGN: Retrospective case-control study. METHODS: We defined and recruited cases of symptomatic hyponatraemia that necessitated hospitalization from January 1996 to April 2002. Controls were selected from 8420 patients being prescribed thiazides and seen at the same institution during that period of time. RESULTS: There were 223 cases and 216 controls, with a median 115 days thiazide use. Cases were older than controls (76 +/- 9 vs. 66 +/- 13 years, p < 0.001) and lighter (52.3 +/- 10.3 vs. 63.4 +/- 3 kg, p < 0.001). By univariate analysis, serum potassium level, use of indapamide, elderly home institutionalization and physical immobility were risk factors for thiazide-induced hyponatraemia, but gender, duration of thiazide use, concomitant therapy with loop diuretics, angiotensin-converting enzyme inhibitors or non-steroidal anti-inflammatory drugs, and renal function were not. By stepwise logistic regression analysis, patient age, body weight and serum potassium were the only independent predictive factors. Each 10-year increment of age was associated with a two-fold increase in risk (hazards ratio 2.14, 95%CI 1.59-2.88). For a 5 kg increment in mass, there was a 27% decrease in odds ratio (odds ratio 0.77, 95%CI 0.68-0.87). One SD increase in serum potassium (0.84 mmol/l) was associated with a 63% decrease in risk (odds ratio 0.37, 95%CI 0.27-0.50; p < 0.0001). DISCUSSION: Hyponatraemia is a common problem after thiazide therapy. Extra caution and close monitoring are warranted when prescribing thiazides for elderly patients with low body mass.     

Study of a carrier solution for the lidocaine infusion therapy in myocardial infarct

Corafusin, an infusion solution containing lidocaine, electrolytes and sorbitol, was tested during 4-day continuous infusion of patients with myocardial infarction. The serum sodium level remained constant within the normal range whereas initially reduced serum potassium and magnesium concentration increased to normal within 24 hours. Both sodium and water balance were generally equilibrated during the entire test period. Testing of lactate and non-esterified fatty acids revealed a significant decrease within the first 24 hours. On the basis of these findings it can be concluded that the infusion solution tested is suited for lidocaine infusion therapy of patients with myocardial infarction.     

The relation between potassium in body fluids and total body potassium in healthy and diabetic subjects.

1. The concentration of potassium in the erythrocytes and the plasma of forty-one normal subjects and twenty-five diabetic patients was measured and the results were used to calculate the total amount of potassium in the erythrocyte mass and the total amount of potassium in the plasma. The total body potassium was measured in a whole-body monitor. 2. In normal subjects a close correlation was found between total erythrocyte potassium and total body potassium and also between total plasma potassium and total body potassium. 3. The regression relation between total body potassium and total erythrocyte potassium in normal subjects was used to predict the total body potassium in diabetic patients. There was reasonable agreement between the measured and predicted total body potassium but there was poor agreement between the measured total body potassium and that predicted from the patient's height and age or height and age or height, weight and age.     

Mediterranean visceral leishmaniasis in HIV-negative adults: a retrospective analysis of 64 consecutive cases (1995-2001)

AIM: To evaluate in a retrospective analysis cases of Mediterranean visceral leishmaniasis (VL) diagnosed in HIV-negative adults during a 7-year period. MATERIALS AND METHODS: Demographic data, previous or underlying diseases, clinical and laboratory features and therapeutic findings were considered. RESULTS: A total of 64 patients were included, of whom 10 (16%) had underlying diseases and two were pregnant. Fever and hepatosplenomegaly were the main presenting symptoms, whereas pancytopenia and an elevated erythrocyte sedimentation rate were observed in all cases. Smears from bone marrow aspirate were positive at microscopy in 62 cases (97%). Twenty-four patients received meglumine antimoniate (MA) given during 21 consecutive days (20 mg/kg per day), and 40 patients liposomal amphotericin B (l-AmB) given at days 1-5 and 10 (3 mg/kg per day). Both groups' clinical and laboratory findings improved, but patients on l-AmB therapy had a faster recovery (85% on l-AmB therapy and 50% on MA therapy showed defervescence at day 5, P < 0.01). Treatment failures were observed in five cases, three (12%) on MA and two (5%) on l-AmB therapy. No significant toxicity was observed in patients treated with l-AmB, whereas three (12%) patients treated with MA showed electrocardiographic abnormalities. CONCLUSIONS: l-AmB therapy may be considered the treatment of choice for any adult patients with Mediterranean VL, since it permits a faster recovery, has a lower incidence of side effects and is useful also in immunosuppressed patients.     

Effect of propranolol on total exchangeable body potassium and total exchangeable body sodium in essential hypertension

Total exchangeable body potassium (KE) was determined in fifteen patients with essential hypertension, and total exchangeable body sodium (NaE) in ten, before and after propranolol administration for 2-3 months. Blood pressure was reduced; serum potassium increased, but KE was unchanged. Serum sodium and NaE were unaffected during therapy. It is concluded that the increase in serum potassium during propranolol treatment could not be attributed to potassium retention, but is possibly due to a displacement from the intra- to the extracellular fluid compartment. The antihypertensive effect of propranolol could not be related to changes in NaE.     

Potential Usefulness of Early Potassium Supplementation for Preventing Severe Hypokalemia Induced by Liposomal Amphotericin B in Hematologic Patients: A Retrospective Study

Purpose

Liposomal amphotericin B (L-AMB) is an essential antifungal agent for patients with hematologic diseases; however, the drug causes severe hypokalemia at a high frequency. Meanwhile, there is little evidence regarding the risk factors for L-AMB–induced severe hypokalemia, and the prevention protocol has not been established. The goal of this study was to identify the risk factors related to severe hypokalemia induced by L-AMB in hematologic patients.

Must we really fear toxicity of conventional amphotericin B in oncological patients?

Fungal infections are an important cause of morbidity and mortality in patients with malignancies. Therefore, the use of amphotericin B (AmB) is essential for these patients. Results from the literature to date show that renal toxicity is the most serious adverse effect of AmB. Renal impairment manifests as a decrease in glomerular filtration and damage to tubular function. Currently, there is no reliable method of preventing nephrotoxicity. We have observed that sodium supplementation alone may not prevent nephrotoxicity. We noted that a large decrease in serum potassium and magnesium was followed by a significant reduction in creatinine clearance and an increase in both serum urea and creatinine. Therefore, we surmised that potassium and magnesium supplements corresponding to the amounts lost by the kidneys, as well as sufficient hydration, are necessary to prevent renal function damage. We decided to test our hypothesis in 32 cancer patients. During AmB therapy, serum electrolyte concentrations and biochemical parameters of renal function and fluid balance were monitored frequently. The daily ion supplementation corresponded to the amount lost through the kidneys. The total duration of administration ranged from 4 to 39 days, with a mean of 13.7 days (median 11.0 days). The mean daily AmB dose was 0.89 mg/kg (median 0.88 mg/kg). The average diuresis was 3863 ml/day, and the median 4000 ml/day. The daily mean i.v.-administered sodium dose was 195.9 mmol, the daily mean dose of i.v. potassium was 103.7 mmol, and the daily mean dose of i.v. magnesium was 9.0 mmol. The frequency of infusion-related side-effects was only 10.0%. These reactions were treated with hydrocortisone. We observed a significant increase in potassium and magnesium lost through the kidneys, and a significant increase in fractional sodium and potassium excretion through the renal tubuli. We did not observe a significant increase in serum creatinine and ion imbalances. Interestingly, the average creatinine clearance did not decrease, but actually increased slightly, though to a statistically insignificant degree, from 1.425 ml/s at the beginning of treatment to 1.589 ml/s on the 20th day of AmB use. Sufficient hydration of patients and ion supplementation corresponding to the amount lost by the kidneys is an effective prophylaxis for prevention of AmB-induced decrease in renal function and for countering imbalances of serum electrolyte concentrations during use of AmB. The frequency of infusion-related side-effects is minimal relative to other reports.     

Effect of long-term penicillamine therapy on erythrocyte CuZn superoxide dismutase activity

The effect of long-term penicillamine therapy on erythrocyte CuZn superoxide dismutase activity was investigated. For comparison the serum ceruloplasmin and serum copper contents were also analysed. Seven of the 11 penicillamine-treated patients had CuZn superoxide dismutase activities below the reference interval of the parameter. Levels down to about 50% of the mean of controls were observed in several cases. In five and in four of the 11 patients respectively decreases in serum ceruloplasmin and serum copper were found. Whereas among the penicillamine-treated patients there was a good correlation between serum ceruloplasmin and serum copper, the correlation between these parameters and erythrocyte CuZn superoxide dismutase was only fair. Erythrocyte CuZn superoxide dismutase is probably a suitable parameter for monitoring intracellular copper availability during penicillamine therapy.     

The phospholipid spectrum of erythrocyte membranes in hemorrhagic fever with renal syndrome

The subjects of the study--patients with severe hemorrhagic fever with renal syndrome--were divided into two groups: those who were on hemodialysis, and those who were not. The study included evaluation of the phospholipid spectrum of erythrocyte membranes in the acute period and during recovery. The results revealed conformational shifts in the structure of the bilipid membrane layer, which were maximal during the acute phase of the disease, as well as less prominent and varied changes in the phospholipid spectrum during recovery. This allows determination of the terms of rehabilitation of the patients and substantiates administration of membrane stabilizers as a part of complex therapy of residual syndrome.