Bernardo Martinez

Proximal Tubule Function and Free Water Clearance: Comparisonbetween Healthy Elderly and Young HIV+ Patients

In previous studies it was documented that proximal tubule sodium reabsorption capability was preserved in healthy elderly, while Thick Ascending Loop of Henle (TALH) one was reduced. Aim: Since, it has also been documented that senile changes are accelerated in HIV patients, we performed a prospective study in order to evaluate if there was a significant difference in proximal and TALH function between healthy elderly and HIV patients. Methods: Proximal and TALH was analyzed by performing hyposaline infusion test in 10 young (≥ 18-≤ 40 years old) HIV volunteers under treatment with tenofovir, free of viral charge, and normal renal function: serum creatinine, urinary sediment, and renal ultrasound), with the control group made up of 10 healthy old volunteers (≥ 65 years old). Results: During the test, it was observed that the HIV group had a significant reduction of natremia (HIV: 133 ± 1 mmol/l vs. healthy elderly: 139 ± 1 mmol/l, p=0.03), serum osmolarity (HIV: 276 ± 4 mOsm/l vs. elderly: 288 ± 3 mOsm/l, p=0.03) and free water clearance (HIV: 3.5 ± 3 ml/min/1.73 m² vs. elderly: 5 ± 8 ml/min/1.73 m², p ≤ 0.01). Besides, HIV patients showed an inadequate and significant increase in their urinary tonicity in comparison with the healthy elderly group: HIV: 170 ± 18 mOsm/l vs. elderly: 90 ± 10, p ≤ 0.01. Regarding proximal tubular function, it was found that it was preserved in both groups. Conclusion: Proximal tubule sodium reabsorption was normal, while free water clearance was significantly reduced in young HIV patients in comparison with healthy elderly volunteers.

Descripción de las características del fenómeno Crowding en la Central de Emergencia de Adultos, en un hospital universitario de alta complejidad: estudio de cohorte retrospectiva

Crowding in Emergency Departments (ED), results from the imbalance between the simultaneous demand for health care and the ability of the system to respond. The NEDOCS scale (National Emergency Department Crowding Scale) measures the degree of crowding in an ED. Aim: To describe ED Crowding characteristics, using the NEDOCS scale, in an Argentinean hospital. Material and Methods: A retrospective cohort study was conducted with all adult patient consultations between July 2013 and July 2014 at the ED of Hospital Italiano de Buenos Aires. We included all hours in the analysis period (365 days x 24 h = 8,760). The NEDOCS value was calculated for each hour using an automatic algorithm and was quantified in a six points score. Levels 4 (overcrowded), 5 (severely overcrowded) and 6 (dangerously overcrowded) were defined as overcrowding. Contour plots analysis was applied to identify patterns. Results: During the study period, 124,758 visits to the ED were registered. Overcrowding was present in 57.7% (5,055) of the analyzed hours. A predominance of scores between four and five was observed between 10:00 and 24:00 hours. The months with predominance of overcrowding were June, July and August (southern winter). Conclusions: The calculation of the NEDOCS score and the analysis of its temporal distribution are highly relevant to identify opportunities for improvement and to develop mechanisms to prevent the highest categories of overcrowding

Creatinine clearance with cimetidine in the elderly: response to Dr. Chia-Ter Chao

We thank Dr. Chia-Ter Chao for his comments about our paper. In responding, we will take the opportunity to correct a mistake. Unfortunately, in the paper, we reported the wrong dose of cimetidine: Instead of 800 mg OD (once per day), it should have been written 800 mg BID (twice a day), a dose most recommended in the literature for achieving a complete creatinine secretion inhibition (we referenced these articles in our original paper). We thank Dr. Chao for pointing out this error and giving us the opportunity to correct it [1–3]. Regarding Dr. Chao0s comment on the accuracy of the method used for evaluating the renal reserve, we would like to emphasize that to evaluate this physiological variable we obtained the DELTA value between a peak GFR value and a basal one; thus, obtained DELTA value will be an accurate representation of the magnitude of GFR increase, independently of the accuracy of the applied method for measuring it. Regarding Dr. Chao0s concern about the accuracy of urine volume measurement, we would like to clarify that all the volunteers had a normal bladder voiding (presence of urine retention was one of the exclusion criteria evaluated before the study), and additionally, their urine residual volume was checked by bladder ultrasound after each micturition (this is mandatory when a timed clearance is evaluated). We agree with Dr. Chao that more research is needed in order to know how the aged kidney handles not only creatinine but also cimetidine.

Erratum to: Renal creatinine handling in very old patients with chronic renal disease

Erratum to: Int Urol NephrolDOI 10.1007/s11255-010-9886-5The original version of our paper unfortunatelycontained a mistake. We reported the wrong dose ofcimetidine: instead of 800 mg OD (once per day) itshould have been written 800 mg BID (twice a day),a dose most recommended in the literature forachieving a complete creatinine secretion inhibition.