Evaluation of methods based on creatinine and cystatin C to estimate glomerular filtration rate in chronic kidney disease

Purpose

Estimated glomerular filtration rate (GFR) is a useful tool for the detection of chronic kidney disease (CKD). Several methods have been proposed, but findings can vary in specific groups such as patients with diabetes, elderly and high and low body mass index and, also, with the stage of CKD. The objective of this study was comparing the accuracy of the currently used equations for estimating GFR with that of the gold standard technetium-(99m)-diethylene triamine pentaacetic acid (99mTc-DTPA).

Methods

We performed a cross-sectional study of 129 patients with all five CKD stages. GFR was estimated using the following: 24-h urine creatinine clearance, Cockcroft–Gault equation, MDRD equation, CKD-EPI equation, Hoek’s cystatin C equation, and isotopic 99mTc-DTPA (as gold standard). We evaluated agreement in the whole study population and according to age, sex, weight, and diabetes.

Results

All methods had good agreement. The best agreement was observed with the cystatin C [intraclass coefficient correlation (ICC) 95 % confidence interval (95 % CI), 0.87 (0.82–0.91)], followed by CKD-EPI [ICC 0.83 (0.77–0.88)]. Twenty-four-hour urine creatinine clearance showed the worst agreement in patients older than 65 years [ICC 0.70 (0.56–0.79)]. The Cockcroft–Gault equation showed the worst agreement in younger than 65 years [ICC 0.64 (0.42–0.79)]. The best agreement for classification in the correct CKD stage was with the cystatin C equation [κ = 0.80 (0.74–0.87)]. GFR was overestimated with all methods in CKD stages 4 and 5.

Conclusions

The methods used in clinical practice are adequate for classification of CKD. Cystatin C is the most accurate method, followed by CKD-EPI. The Cockcroft–Gault equation is not accurate in young patients. Twenty-four-hour urine creatinine clearance loses accuracy in patients aged older than 65 years.     

Neurofibromatosis diagnosed on CT with MR correlation

We report a young man with asymptomatic neurofibromatosis type-1 initially diagnosed on CT. CT demonstrated the typical lesions of this disorder: extensive cervical, thoracic, abdominal and pelvic masses and spinal alterations. The symmetrical distribution and the location of the lesions as well as their attenuation are characteristic of NF-1 and may be considered diagnostic for this disease.     

Antinociceptive Effect of Low-Dose Intrathecal Neostigmine Combined with Intrathecal Morphine following Gynecologic Surgery

Background: The purpose of this study was to determine whether combination of 1-5 [mu]g intrathecal neostigmine would enhance analgesia from a fixed intrathecal dose of morphine.

Methods: A total of 60 patients undergoing gynecologic surgery were randomized to one of five groups. Patients received 15 mg bupivacaine plus 2 ml of the test drug intrathecally (saline, 100 [mu]g morphine, or 1-5 [mu]g neostigmine). The control group received spinal saline as the test drug. The morphine group received spinal morphine as test drug. The morphine + 1 [mu]g neostigmine group received spinal morphine and 1 [mu]g neostigmine. The morphine + 2.5 [mu]g neostigmine group received spinal morphine and 2.5 [mu]g neostigmine. Finally, the morphine + 5 [mu]g neostigmine group received spinal morphine and 5 [mu]g neostigmine.

Results: The groups were demographically similar. The time to first rescue analgesic (minutes) was longer for all patients who received intrathecal morphine combined with 1-5 [mu]g neostigmine (median, 6 h) compared with the control group (median, 3 h) (P < 0.02). The morphine group (P < 0.05) and the groups that received the combination of 100 [mu]g intrathecal morphine combined with neostigmine (P < 0.005) required less rescue analgesics in 24 h compared with the control group. The incidence of perioperative adverse effects was similar among groups (P > 0.05).     

Hydroxytyrosol increases norepinephrine transporter function in pheochromocytoma cells

INTRODUCTION: The norepinephrine transporter is responsible for the intracellular uptake of (131)I- iodometaiodobenzylguanidine ((131)I-MIBG), which is used for the diagnostic localization and treatment of pheochromocytomas as well as other tumors such as neuroblastomas and carcinoids. This agent is variably delivered into tumor cells by the norepinephrine transporter, but few studies have shown treatments that work to increase norepinephrine transporter activity. The objective of the present study was to test the possible beneficial effects of hydroxytyrosol in enhancing norepinephrine transporter function, which may have implications for its combined use with (131)I-MIBG in the diagnosis and treatment of pheochromocytomas. METHODS: Rat pheochromocytoma PC12 cells were labeled with [(3)H]-norepinephrine in the presence or absence of different concentrations of hydroxytyrosol, a naturally occurring compound with strong antioxidant properties, followed by measurements of uptake and release of radiolabeled norepinephrine. RESULTS: Hydroxytyrosol pronouncedly increased norepinephrine transporter activity, with the rapid onset excluding effects on norepinephrine transporter expression levels. Concomitant with increased norepinephrine transporter activity, hydroxytyrosol caused a decrease of both spontaneous and evoked norepinephrine release, indicating that it affects pre-existing plasma membrane-associated norepinephrine transporter, rather than the incorporation of novel norepinephrine transporter molecules into the plasma membrane. CONCLUSION: Hydroxytyrosol potently enhances norepinephrine transporter activity in pheochromocytoma PC12 cells, suggesting that combinatorial therapy employing hydroxytyrosol may improve the effectiveness of (131)I-MIBG as a diagnosis and treatment modality.     

Epidural morphine and neostigmine for postoperative analgesia after orthopedic surgery

In this study, we examined the side effects and analgesia of the combination of epidural neostigmine and morphine in patients undergoing orthopedic surgery. Sixty patients undergoing knee surgery were divided into four groups. The intrathecal anesthetic was 15 mg of bupivacaine. The epidural test drug was diluted in saline to a final volume of 10 mL. The control group received saline as the epidural test drug. The morphine group received 0.6 mg of epidural morphine. The neostigmine group (NG) received 60 micro g of epidural neostigmine. The morphine/neostigmine group received 0.6 mg of epidural morphine combined with 60 micro g of epidural neostigmine. The groups were demographically the same and did not differ in intraoperative characteristics. The visual analog scale score at first rescue analgesic and the incidence of adverse effects were similar among groups (P > 0.05). One patient from the NG complained of intraoperative nausea, closely related to spinal hypotension. Postoperatively, two patients from the NG had vomited once. The time (min) to first rescue analgesic was longer in the morphine/neostigmine group ( approximately 11 h) compared with the other groups (P < 0.05). The analgesic consumption (number of analgesic administrations in 24 h) was larger in the control group compared with the other groups (P < 0.05). IMPLICATIONS: The combination of epidural morphine and epidural neostigmine resulted in postoperative analgesia (11 h) devoid of side effects, being an alternative analgesic technique in the population studied.