Applications of external cavity diode laser-based technique to noninvasive clinical diagnosis using expired breath ammonia analysis: chronic kidney disease, epilepsy

An external cavity laser (ECL)-based off-axis cavity-enhanced absorption spectroscopy was applied to noninvasive clinical diagnosis using expired breath ammonia analysis: (1) the correlation between breath ammonia levels and blood parameters related to chronic kidney disease (CKD) was investigated and (2) the relationship between breath ammonia levels and blood concentrations of valproic acid (VAP) was studied. The concentrations of breath ammonia in 15 healthy volunteers, 10 epilepsy patients (before and after taking VAP), and 27 patients with different stages of CKD were examined. The range of breath ammonia levels was 120 to 530 ppb for healthy subjects and 710 to 10,400 ppb for patients with CKD. There was a statistically significant positive correlation between breath ammonia concentrations and urea, blood urea nitrogen, creatinine, or estimated glomerular filtration rate in 27 patients. It was demonstrated that taking VAP gave rise to increasing breath ammonia levels. A statistically significant difference was found between the levels of exhaled ammonia (NH3) in healthy subjects and in patients with epilepsy before and after taking VAP. The results suggest that our breath ammonia measurement system has great potential as an easy, noninvasive, real-time, and continuous monitor of the clinical parameters related to epilepsy and CKD.

Does the inhibition of renin-angiotensin system decrease inter-dialytic weight gain in anuric hemodialysis patients?

OBJECTIVE

Knowledge about the inhibition of centrally located angiotensin-I (AT-I) receptors by highly lipophilic AT-I receptor blockers and its' effect are limited with experimental studies. Thus, we aimed to investigate the effect of Telmisartan on Inter-dialytic weight gain (IDWG) % and echocardiographic measurements in anuric hemodialysis (HD) patients.

PATIENTS AND METHODS

A total of forty-one anuric HD patients with ≥ 6 months maintenance on HD were included in this prospective, randomized and self-controlled study. Four weeks prior the study, angiotensin converting enzyme blockers and AT-I receptor blocker drugs were stopped. Patients were assessed three times during the study protocol. These are baseline, three months later (without Telmisartan period) and three months after Telmisartan therapy.

RESULTS

IDWG % was significantly decreased in the period of with Telmisartan compared to period without Telmisartan (5.6 ± 1.0% vs 5.3 ± 1.0%, p = 0.03). After the administration of Telmisartan left ventricule end-diastolic diameter (LVEDD) (p = 0.001) and inferior vena cava diameter (IVCD) (19.1 ± 3.8 mm vs 17.3 ± 4.2 mm, p = 0.001) were significantly decreased compared to the period of without Telmisartan. Despite of significantly changes observed in IVCD and LVEDD measurements in a period without Telmisartan, there was no significantly difference in left ventricular mass index (LVMI) measurements in this period. However, LVMI was significantly regressed after the administration of Telmisartan (269.3 ± 82.7 g vs 256.3 ± 70.3 g, p = 0.003 respectively).

CONCLUSIONS

Treatment of anuric HD patients with Telmisartan at a dose of 40 mg a day reduces IDWG%, LVEDD and IVCD measurements. Further studies investigating the long-term effect of these beneficial effects on clinical outcomes are necessary.

The upper extremity musculoskeletal complications in dialysis patients: comparison between hemodialysis and peritoneal dialysis

OBJECTIVES

The aim of this study was to compare the upper extremity musculoskeletal complications in the patients who had been receiving hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD).

MATERIAL AND METHODS

The patients who had been receiving HD (n=17) or CAPD (n=15) were included to the study. The age, gender, duration of dialysis were recorded. The physical findings related to musculoskeletal system in the upper extremity were researched. The cervical, shoulder, hand standard radiographies and shoulder magnetic resonance imaging were investigated.

RESULTS

The mean duration of HD and CAPD were 53.60 ± 36.03 and 49.17 ± 33.14 months, respectively (p=0.720). Only 6.3% of the CAPD group had signs of carpal tunnel syndrome (CTS). There were not any differences in the frequency of cervical destructive spondyloarthropathy, decreased height of vertebral corpus in the examination of cervical radiography (p=0.579) and also in the frequency of erosions in the humeral head and bones of hand, cyst in the clavicula, erosive osteoarthropathy and osteoporosis detected in the bones of hands (p> 0.005). In the examination of shoulder MR imaging, 80% of the HD group and 47.1% of the CAPD group had supraspinatus tendinitis (p=0.059). The frequency of subscapularis, biceps and infraspinatus tendinitis were not different in HD and CAPD groups (p> 0.05).

CONCLUSION

The musculoskeletal system complications of the upper extremity were common in the patients undergoing dialysis therapy. The most common complications were osteoporosis of the hand region and supraspinatus tendinitis.

LEVEL OF EVIDENCE

Prospective, Level 2b.

Psychological symptoms are greater in caregivers of patients on hemodialysis than those of peritoneal dialysis

BACKGROUND

The purpose of this study was to evaluate and compare psychosocial characteristics in caregiving relatives (caregivers) of hemodialysis (HD) and peritoneal dialysis (PD) patients.

METHODS

Thirty-three caregivers (17 women, 16 men) of HD patients, 27 caregivers (11 women, 16 men) of PD patients, and a control group of 49 subjects who do not care for family members with chronic illness (23 women, 26 men) are included in this study. The brief symptom inventory (BSI), social disability schedule (SDS), and brief disability questionnaire (BDQ) were used for the psychosocial evaluation.

RESULTS

The mean age, men-to-women ratios, duration of education, and distribution of marital status did not differ significantly among the three groups. In addition, dialysis duration and distribution of caregiver type were not different between the HD and PD groups. Although the mean global severity index scores of the three groups were similar, somatization and depression scores from BSI subitems were greater in the HD group than the scores of the PD and control groups. Although the mean SDS and BDQ scores were higher in the HD group, the differences did not achieve statistical significance. BSI subitems such as somatization, obsession-compulsion, interpersonal sensitivity, depression, and anxiety were positively correlated among themselves. Hostility and somatization were negatively correlated with age and education, respectively. Nevertheless, somatization was positively correlated with age. Social disability was negatively correlated with duration of education.

CONCLUSION

Somatization and depression are greater in the caregivers of center HD patients compared to PD and control groups. According to the findings of this study, we suggest that caregiving family members of dialysis patients especially on HD also should be evaluated for psychosocial problems and supported as needed. Further studies are needed to explore whether psychosocial parameters of caregivers predict outcomes for caregivers and patients.

The relationship of amelogenesis imperfecta and nephrocalcinosis syndrome

AIM

To analyze the prevalence and associated oral findings of nephrocalcinosis in a group of patients affected with amelogenesis imperfecta (AI). The relationship between types of AI and nephrocalcinosis were also evaluated.

DESIGN

This study examines patients who were referred to Pediatric Dentistry Department of SDU between the years of 2002-2007 and who, upon clinical and radiological examination, were diagnosed with AI and treated. Patients were offered information about the possibility of nephrocalcinosis syndrome. Patients who agreed to have tests carried out on their renal system were advised to visit the department of nephrology at the clinic.

RESULTS

Suspicious radiopacity was observed during renal ultrasonography of a controlled number of patients with hypoplastic type AI. Laboratory results revealed low Ca values (100-300 mg/days) and normal P values (0.4-1.3 g/days). Delayed eruption, gingival hyperplasia, pulp stones and orthodontic problems were also observed in the same patient groups.

CONCLUSION

Although renal findings were observed in a few patients, pediatric dentists are the doctors who are the first to have early contact with this patient group. Because of the potential risk of nephrocalcinosis, early diagnosis may offer good prognosis.

The effect of serum albumin level on iron-induced oxidative stress in chronic renal failure patients

BACKGROUND

Intravenous iron (IVIR) administration is widely used to treat anemia in chronic renal failure (CRF) patients and causes oxidative stress. Despite the fact that proteins are extremely susceptible to oxidative stress, there have been no studies investigating the relationship between the severity of iron-induced acute oxidative stress and serum albumin. Therefore, we wanted to investigate the relation between the severity of iron-induced acute oxidative stress and serum albumin level in CRF patients.

METHODS

A total of 68 patients (22 on hemodialysis, 24 on continuous ambulatory peritoneal dialysis and 22 predialytic CRF) with absolute iron deficiency were included to the study. Patients with acute inflammatory status, serum ferritin level > or = 100 ng/mL, transferrin saturation > or = 20%, hemoglobin level > or = 12 g/dL or serum C-reactive protein (CRP) level > or = 10 mg/dL were excluded. Serum direct 8-isoprostoglandin F2 alpha (IsoPG-F2 alpha) level was used as an oxidative stress marker. After baseline sampling, 100 mg ferric sucrose was infused within 30 minutes. Blood samples were drawn to assess changes in oxidative stress marker at the end of the IVIR infusion and at 240 minutes. Patients with serum albumin level <4 g/dL were defined as hypoalbuminemic and > or = 4 g/dL as normoalbuminemic.

RESULTS

There were 34 hypoalbuminemic and 34 normoalbuminemic patients. Serum IsoPG-F2 alpha level increased in all patients after the administration of IVIR. The severity of iron-induced acute oxidative stress was more prominent in patients with a low serum albumin level. Serum albumin level, presence of diabetes mellitus (DM) and hemoglobin level were found as significant predictors of time-dependent changes in serum IsoPG-F2 alpha level. When the analyses were repeated in nondiabetic patients, serum albumin level was similarly found to be a significant predictor of time-dependent changes in serum IsoPG-F2 alpha level.

CONCLUSION

This study demonstrated a negative interaction between iron-induced acute oxidative stress and serum albumin level in CRF patients. Because CRF patients with low serum albumin level are at greater risk for iron-induced acute oxidative stress, new strategies are necessary in this population.

Percutaneous placement of central venous catheters: comparing the anatomical landmark method with the radiologically guided technique for central venous catheterization through the internal jugular vein in emergent hemodialysis patients

PURPOSE

To compare the success and immediate complication rates of the anatomical landmark method (group 1) and the radiologically (combined real-time ultrasound and fluoroscopy) guided technique (group 2) in the placement of central venous catheters in emergent hemodialysis patients.

MATERIAL AND METHODS

The study was performed prospectively in a randomized manner. The success and immediate complication rates of radiologically guided placement of central venous access catheters through the internal jugular vein (n=40) were compared with those of the anatomical landmark method (n=40). The success of placement, the complications, the number of passes required, and whether a single or double-wall puncture occurred were also noted and compared.

RESULTS

The groups were comparable in age and sex. The indication for catheter placement was hemodialysis access in all patients. Catheter placement was successful in all patients in group 2 and unsuccessful in 1 (2.5%) patient in group 1. All catheters functioned adequately and immediately after the placement (0% initial failure rate) in group 2, but 3 catheters (7.5% initial failure rate) were non-functional just after placement in group 1. The total number of needle passes, double venous wall puncture, and complication rate were significantly lower in group 2.

CONCLUSION

Percutaneous central venous catheterization via the internal jugular vein can be performed by interventional radiologists with better technical success rates and lower immediate complications. In conclusion, central venous catheterization for emergent dialysis should be performed under both real-time ultrasound and fluoroscopic guidance.

Insulin resistance in critically ill patients with acute renal failure

Mortality in critically ill patients with acute renal failure (ARF) remains high. Hyperglycemia associated with insulin resistance has been associated with adverse outcomes in critically ill intensive care unit (ICU) patients but has not been examined specifically in patients with ARF. We used data from a subcohort ( n = 90) of the Program to Improve Care in Acute Renal Disease (PICARD), an observational study of 618 adult ICU patients with ARF in whom nephrology service consultation was obtained. We obtained simultaneous measurements of serum glucose, insulin, insulin-like growth factor (IGF)-I, and IGF-1 binding proteins (IGFBP) in 90 patients. Daily glucose determinations were obtained from a larger fraction of the PICARD cohort ( n = 509). Among the 90 patients with intensive metabolic monitoring, glucose concentrations in survivors were significantly lower than in nonsurvivors throughout the 5-wk period ( P = 0.008, adjusted P = 0.013). In the larger PICARD cohort ( n = 509), hyperglycemia was also significantly associated with in-hospital mortality. Mean insulin concentrations were significantly higher (431 ± 508 vs. 234 ± 189 pmol/l, P = 0.03), mean homeostasis model of insulin resistance levels were significantly higher (24.1 ± 30.0 vs. 11.7 ± 12.5, P = 0.04), and IGFBP-3 concentrations were significantly lower (1,190 ± 498 vs. 1,470 ± 581 μg/l, P = 0.02) among nonsurvivors compared with survivors. Insulin resistance as defined by hyperglycemia in the setting of higher insulin concentrations may be associated with mortality in critically ill patients with ARF. The IGF-IGFBP axis may play an important role in this process.

Effect of Renal Transplantation on Biomarkers of Inflammation and Oxidative Stress in End-Stage Renal Disease Patients

BACKGROUND

Chronic kidney disease patients have a high prevalence of inflammation and oxidative stress, and this has been associated with the excess cardiovascular morbidity and mortality observed in this population. Because maintenance hemodialysis is ineffective in controlling these factors, we hypothesized that restoration of kidney function by transplantation would be required to improve uremic inflammation and oxidative stress.

METHODS

This was a prospective cohort study evaluating time-dependent changes in biomarkers of inflammation and oxidative stress before and after renal transplantation. Nineteen end-stage renal disease (ESRD) patients (age 38.3+/-13.7 years, 58% male, 95% white, 21% diabetic) undergoing living-donor renal transplantation were enrolled. C-reactive protein (CRP), interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-alpha, protein-associated carbonyl content, and F2-isoprostanes were assessed at 1 week pretransplantation and at 1 week and 2 months posttransplantation.

RESULTS

Pretransplant levels of the pro-inflammatory proteins IL-6, TNF-alpha, and CRP, as well as the oxidative stress markers plasma protein carbonyls and F2-isoprostanes, were significantly elevated in ESRD patients compared with healthy control subjects. We observed rapid and significant declines in all of these biomarkers after transplantation that persisted for 2 months.

CONCLUSIONS

Our findings indicate that restoration of renal function by transplantation improves the chronic inflammation and increased oxidative stress associated with uremia, which may contribute to the improved survival afforded to ESRD patients by renal transplantation.

Plasma cytokine levels predict mortality in patients with acute renal failure

BACKGROUND

Critically ill patients with acute renal failure (ARF) experience a high mortality rate. Animal and human studies suggest that proinflammatory cytokines lead to the development of a systemic inflammatory response syndrome (SIRS), which is temporally followed by a counter anti-inflammatory response syndrome (CARS). This process has not been specifically described in critically ill patients with ARF.

METHODS

The Program to Improve Care in Acute Renal Disease (PICARD) is a prospective, multicenter cohort study designed to examine the natural history, practice patterns, and outcomes of treatment in critically ill patients with ARF. In a subset of 98 patients with ARF, we measured plasma proinflammatory cytokines [interleukin (IL)-1beta, IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha)], the acute-phase reactant C-reactive protein (CRP), and the anti-inflammatory cytokine IL-10 at study enrollment and over the course of illness.

RESULTS

When compared with healthy subjects and end-stage renal disease patients on maintenance hemodialysis, patients with ARF had significantly higher plasma levels of all measured cytokines. Additionally, the proinflammatory cytokines IL-6 and IL-8 were significantly higher in nonsurvivors versus survivors [median 234.7 (interdecile range 64.8 to 1775.9) pg/mL vs. 113.5 (46.1 to 419.3) pg/mL, P= 0.02 for IL-6; 35.5 (14.1 to 237.9) pg/mL vs. 21.2 (8.5 to 87.1) pg/mL, P= 0.03 for IL-8]. The anti-inflammatory cytokine IL-10 was also significantly higher in nonsurvivors [3.1 (0.5 to 41.9) pg/mL vs. 2.4 (0.5 to 16.9) pg/mL, P= 0.04]. For each natural log unit increase in the levels of IL-6, IL-8, and IL-10, the odds of death increased by 65%, 54%, and 34%, respectively, corresponding to increases in relative risk of approximately 30%, 25%, and 15%. The presence or absence of SIRS or sepsis was not a major determinant of plasma cytokine concentration in this group of patients.

CONCLUSION

There is evidence of ongoing SIRS with concomitant CARS in critically ill patients with ARF, with higher levels of plasma IL-6, IL-8, and IL-10 in patients with ARF who die during hospitalization. Strategies to modulate inflammation must take into account the complex cytokine biology in patients with established ARF.

Urea space and total body water measurements by stable isotopes in patients with acute renal failure

BACKGROUND

Knowledge of urea volume of distribution (Vurea) in patients with acute renal failure (ARF) is critical in order to prescribe and monitor appropriate dialytic treatment. We have recently shown that in ARF patients, Vurea estimation by urea kinetic modeling is significantly higher than total body water (TBW) by anthropometric estimation. However, these estimates of Vurea and TBW have not been validated by isotopic methods, considered as reference measurement standards.

METHODS

In this study, we measured Vurea by [13C]urea and TBW by deuterium oxide (D2O) in 21 patients with ARF (14 males, 7 females, age 62.0 +/- 10.6 years old, 83% Caucasian, 17% African American) at three different centers. These measurements were compared to TBW estimates from anthropometric and bioelectrical impedance (BIA) measurements.

RESULTS

Our results show that Vurea by [13C]urea (51.0 +/- 11.7 L) is significantly higher than TBW estimated by all other methods (TBW by D2O: 38.3 +/- 9.8 L, P < 0.001; TBW by BIA: 45.7 +/- 15.7 L, P= 0.08; TBW by Watson formula: 38.3 +/- 7.3 L, P < 0.001; TBW by Chertow formula: 39.3 +/- 7.8 L, P= 0.002, all versus Vurea). Despite significant overestimation of the absolute value and considerable variation, Vurea significantly correlated with TBW by BIA (r= 0.66, P < 0.01) and TBW by D2O (r= 0.5, P= 0.04). There was also significant correlation between D2O and BIA determined TBW (r= 0.8, P < 0.001).

CONCLUSION

In terms of useful guidelines to prescribe a specific dose of dialysis in patients with ARF, conventional estimates of TBW as surrogates for Vurea should be used with caution. We propose that these conventional estimates of TBW should be increased by approximately 20% (a factor of 1.2) to avoid significant underdialysis.

Amyloidosis of the tongue with kappa light chain disease

A 70-year-old woman presented with a painful, red tongue with papules associated with xerostomia and systemic symptoms including weight loss, difficulty in swallowing and breathing, haemochezia and leg swelling. Biopsy from the tongue demonstrated amyloid deposits and, on further investigation, kappa chain disease was diagnosed. Primary systemic amyloidosis was diagnosed and the patient died within weeks of presentation.

Response to triple treatment with omeprazole, amoxicillin, and clarithromycin for Helicobacter pylori infections in continuous ambulatory peritoneal dialysis patients

In this study, the response to triple treatment with omeprazole, amoxicillin, and clarithromycin was investigated in continuous ambulatory peritoneal dialysis (CAPD) patients with Helicobacter pylori (Hp) infections. The study enrolled 20 CAPD patients (11 male, 9 female) who had dyspeptic complaints. The mean age of the patients was 46 (range: 21-65). The study also enrolled, as a control group, 124 patients (66 male, 58 female) who had no systemic disease, but who had upper gastrointestinal endoscopy for dyspeptic complaints. The mean age of the patients in the control group was 47 years (range: 20-74 years). Upper gastrointestinal endoscopy, rapid urease test (CLO test), and direct histologic examination were carried out to detect Hp infection. Hp infection was detected in 10 cases (50%) in the CAPD group and in 53 cases (43%) in the control group. In both groups, patients with Hp infection received the triple treatment of omeprazole 20 mg twice daily for 30 days, amoxicillin 500 mg thrice daily for 15 days, and clarithromycin 500 mg thrice daily for 15 days. To assess response to treatment, upper gastrointestinal endoscopy, CLO test, and direct histologic examination were repeated 3 months after initiation of the treatment. Hp was eradicated in all of the 11 CAPD patients (100%), and in 42 of the control patients (92%). Our results suggest that the triple treatment with omeprazole, amoxicillin, and clarithromycin for Hp infection is as effective in CAPD patients as in the normal population.