[Physical principles of renal replacement therapy applied to end stage renal disease patients]

Piperacillin Population Pharmacokinetics and Dosing Regimen Optimization in Critically Ill Children Receiving Continuous Renal Replacement Therapy

We aimed to develop a piperacillin population pharmacokinetic (PK) model in critically ill children receiving continuous renal replacement therapy (CRRT) and to optimize dosing regimens. The piperacillin plasma concentration was quantified by high-performance liquid chromatography. Piperacillin PK was investigated using a nonlinear mixed-effect modeling approach. Monte Carlo simulations were performed to compute the optimal scheme of administration according to the target of 100% interdose interval time in which concentration is one to four times above the MIC (100% fT > 1 to 4× MIC). A total of 32 children with a median (interquartile range [IQR]) postnatal age of 2 years (0 to 11), body weight (BW) of 15 kg (6 to 38), and receiving CRRT were included. Concentration-time courses were best described by a one-compartment model with first-order elimination. BW and residual diuresis (Q_u) explained some between-subject variabilities on volume of distribution (V), where [Formula: see text], and clearance (CL), where [Formula: see text], where CL_pop and V_pop are 6.78 L/h and 55.0 L, respectively, normalized to a 70-kg subject and median residual diuresis of 0.06 mL/kg/h. Simulations with intermittent and continuous administrations for 4 typical patients with different rates of residual diuresis (0, 0.1, 0.25, and 0.5 mL/kg/h) showed that continuous infusions were appropriate to attain the PK target for patients with residual diuresis higher than 0.1 mL/kg/h according to BW and MIC, while for anuric patients, less frequent intermittent doses were mandatory to avoid accumulation. Optimal exposure to piperacillin in critically ill children on CRRT should be achieved by using continuous infusions with escalating doses for high-MIC bacteria, except for anuric patients who require less frequent intermittent doses.

3D Low-Cost Equipment for Automated Peritoneal Dialysis Therapy

A breakthrough in peritoneal dialysis (PD) therapy occurred in 1977 with the development of continuous ambulatory peritoneal dialysis (CAPD). Its simplicity, low cost, and ease with which CAPD could be performed on patients at home contributed to the popularity of this procedure. However, there is a need for continuous improvement in building optimal systems for incident chronic kidney disease (CKD) patients. This research showed the design and construction of a simplified prototype of low-cost automated peritoneal dialysis (APD) equipment that meets international standards to automatically regulate infusion and fluid drainage in and out of a patient with low margins of error. Experimental tests allowed the adjustment of the RPM values concerning the flow rate provided. In addition, thanks to the pressure sensor, it was possible to observe a fluctuation ranging from 9 to 13 kPa, which is within the permissible average specified in the catalogs of medical instruments and equipment. Furthermore, a turbidity sensor was added to decrease the possibility of presenting peritonitis. The results showed absolute values of flow, angular velocity, and pressure that it could deliver for use in APD therapies. Finally, the construction of the APD equipment is presented generally, showing the electronic and mechanical components that constitute it.

Effects of Hemodialysis on Intraocular Pressure and Ocular Biological Parameters in Different Angle Structures

Purpose

This study is aimed at evaluating the effects of hemodialysis on intraocular pressure (IOP) and exploring the possible factors affecting IOP.

Methods

Fifty-two patients with hemodialysis (HD) that were diagnosed with chronic renal failure by nephrology were divided into four groups: wide angle, narrow angle, extremely narrow angle, and closed angle. IOP, central anterior chamber depth (ACD), lens thickness (LT), angle opening distance (AOD), trabecular-iris angle (TIA), iris thickness (IT), and ciliary body thickness (CBT) were recorded before and after HD. The Pearson coefficient test was used to determine correlations among changes in IOP and AOD, ACD, TIA, IT, CBT, and LT.

Results

The IOP in the extremely narrow angle group had significant difference compared with that in the wide angle group and narrow angle group (P < 0.05, P < 0.01). In the narrow angle group, change in LT was positively correlated with change in IOP (P < 0.05). In the extremely narrow angle group, change in LT was positively correlated with change in IOP (P<0.01), whereas changes in AOD and TIA were negatively correlated with change in IOP (P < 0.01; P < 0.05).

Conclusion

The effect of HD on IOP varies with the structure of the anterior chamber. The increasing of IOP in the extremely narrow-angle group is related with the changes of structure of anterior chamber.

Analysis of the relationship between postoperative ophthalmic complications and dialysis time of pre-kidney transplantation

AIM

To determine the influence of the dialysis time before kidney transplantation on postoperative ophthalmic complications.

METHODS

One hundred and eighty three patients who were given the follow-up after kidney transplantation were selected, including 124 males and 59 females. The dialysis time before kidney transplantation was (2.9±2.1) years. Among them, there were 93 cases having cadaveric renal transplantation and 90 cases having living relative renal transplantation. The conditions of ophthalmic complications in all the patients after kidney transplantation were investigated and the incidence rate on ophthalmic complications having different dialysis time before kidney transplantation was given Chi-square test and Chi-square linear trend test.

RESULTS

Among 183 patients with kidney transplantation, 95 patients (51.9%) had at least one ophthalmic complication and the rest 88 patients (48.1%) had no significant abnormality at the eye region. The most common ophthalmic complications were pinguecula/conjunctival degeneration (31 cases), the following was caligo lentis (24 cases). The main manifestations were grayish white granule and plaque turbidity occurred in posterior capsule at the posterior pole of crystaline lens. The angulus iridocornealis of 5 patients (5.3%) with cataract and glaucoma were all open-angle through the detection by gonioscope. Through visual field examination, there were 2 patients with paracentral scotoma, 2 patients with arcuate scotoma and one case with nasal step.

CONCLUSION

The experiments verify that the incidence of glaucomawas relates to the dialysis time before kidney transplantation, and the incidence rate might be higher if the dialysis time is longer.