Accuracy assessment of a PION TCI pump based on international standards

BACKGROUND: Inaccuracies associated with target-controlled infusion (TCI) delivery systems are attributable to both software and hardware issues, as well as pharmacokinetic variability. However, little is known about the inaccuracy of the syringe pump operating in TCI mode. This study aimed to evaluate the accuracy of the TCI pump based on international standards.METHODS: A test apparatus for accuracy evaluation of a syringe pump (PION TCI®, Bionet Co. Ltd.) was designed to apply the gravimetric method. Pump accuracy was evaluated in terms of deviation defined by the following equation: infusion rate deviation (%) = (Rate(mea) − Rate(est)) / Rate(est) × 100, where Rate(mea) is the infusion rate (ml/h) as measured by the gravimetric system, and Rate(est) is the infusion rate (ml/h) as estimated by the pump. An infusion rate representing TCI mode was determined from previous clinical trial data which evaluated the predictive performance of the pharmacokinetic model. The PION TCI pump used in that clinical trial was used to evaluate accuracy of the syringe pump. The distribution of infusion rates obtained from the clinical trial was calculated, and the median value of the distribution was determined as the representative value.RESULTS: The representative infusion rate representing TCI mode was 31 ml/h, at which the infusion rate deviation was 4.5 ± 1.6%.CONCLUSIONS: The inaccuracy of the syringe pump contributing to TCI system inaccuracy is insignificant.

Predictive performance of a target controlled infusion of Aquafol(TM) by use of a PION TCI(R) pump

BACKGROUND: The performance of a target controlled infusion (TCI) system needs to be confirmed in a clinical setting. Aquafol(TM), a microemulsion propofol, can be used for TCI with its pharmacokinetic parameters. The aim of this study is to evaluate the predictive performance of Aquafol(TM) TCI by using a PION TCI(R) pump incorporating the previously established pharmacokinetic parameters and ke0. METHODS: Thirty adult patients were enrolled in the study. General anesthesia was maintained with TCI of Aquafol(TM) and remifentanil using a PION TCI(R) pump. During the maintenance of anesthesia with a constant target effect-site concentration of propofol for at least for 20 minutes, blood was drawn and the propofol plasma concentration was measured. The predictive performance of Aquafol(TM) TCI was evaluated by determining the median performance error (MDPE), median absolute performance error (MDAPE), divergence, and wobble from the intra-individual and pooled performance errors. The acceptability of the TCI system was determined based on the pooled predictive performance. RESULTS: A total of 153 propofol blood samples were analyzed. The estimates of pooled MDPE, MDAPE, divergence and wobble were 8.59% (1.61), 19.1% (1.12), -1.12%/h and 9.87% (1.01), respectively. The MDAPE indicating the accuracy of the TCI infusion system was within the clinically acceptable range (< 20-30%) and the bias (MDPE) was also acceptable (< 10-20%). CONCLUSIONS: The performance of Aquafol(TM) TCI using a PION TCI(R) pump was acceptable for the clinical use.

Bilateral Posterior Ischemic Optic Neuropathy associated with Hemodialysis in a patient with Chronic Renal Failure

Bilateral posterior ischemic optic neuropathy (PION) has rarely been documented in chronic renal failure (CRF). A 78-year-old woman with CRF, who had undergone hemodialysis for 14 years, was admitted due to rapidly progressive visual loss. Her pupils were unreactive to light, but ocular motility and fundoscopic examinations were normal. A brain MRI with angiogram revealed no abnormality and a VEP showed no wave formation bilaterally. Intravenous corticosteroid therapy was conducted without improvement. We report a case of bilateral PION associated with CRF, presumably due to chronic hypotension and anemia occurring during hemodialysis.

Academic Influence on Japan of Edmund Alexander Parkes, Pioneer of Modern Hygiene

In Japan, Max von Pettenkofer is highly regarded as a pioneer of modern hygiene. The contribution of Edmund Alexander Parkes, however, is not yet sufficiently appreciated. This paper outlines the life and achievements of E.A. Parkes and discusses his influence in Japan.

Characterization of Heparin:PF4 Isoantibody Interaction to Platelets in Heparin-Induced Thrombocytopenia/ Thrombosis / 대한임상병리학회지

BACKGROUND: Heparin-induced thrombocytopenia/ thrombosis (HITT) is recognized as the most frequent and fatal symptom complexes in patients receiving heparin therapy. The antibodies of HITT are not directly bound to heparin but bound to complexes of heparin and platelet factor 4 (PF4) derived from platelet alpha-granules. That is, HITT IgG antibody-heparin-PF4 immune complexes are bound to FcgammaRII receptor of platelets, which induced thrombocytopenia. Some researches showed the antibodies reactive to platelets could be IgM or IgA as well as IgG. So in this study, the authors tried to explain the molecular basis of heparin-PF4-isoantibody complexes . METHODS: In HITT patients who had received long-term heparin therapy, we determined HITT isoantibodies and titers using heparin:PF4 ELISA. When fifteen HITT patients with high titer antibodies (more than 1 : 100) were selected, reaction patterns of isoantibodies with the platelets were examined through serotonin release test and flow cytometry. RESULTS: All patients showed one or more isotype antibodies and the most frequent isotype was IgGl (nine patients) . In the presence of optimal concentra pion of heparin and PF4, ten patients had antibodies which activated platelets, and all of them were positive in serotonin release test. Reactive plasmas had IgGl, IgG3, IgA or IgM antibodies, and each of them except one had IgGl. These platelet activations could be blocked in vitro by anti-IV.3 antibody. Non-reactive plasmas were negative In serotonin release assay nor had TgGl. The plasmas 4hat had two or more isoantibodies showed a similar pattern of the IgG antibody by flow cytometry. CONCLUSIONS: The HITT antibodies can be all kinds of antibody isotopes, but IgA and IgM may not bind to the platelets directly. It seems to be possible only after reacting with heparin-PF4-IgG complexes.

Comparison of Maximal Removal Rate of Indocyanine Green and Monoethylglycinexylidide Test in Quantitative Assessment of Hepatic Function / 대한임상병리학회지

BACKGROUND: The maximal removal rate of indocyanine green (ICG Rmax), which has been used as a useful indicator of quantitative assessment of the hepatic function, has some disadvantages such as high cost, requirement of multiple sampling, and long turn-around time. This study was designed to clarify that the measurement of the lidocaine metabolite, monoethylglycinekylidide (MEGX) test, can replace the ICG Rmax. And in healthy adults, MEGX forma pion was measured and compared according to methods of measurement and serf. METHOD: In 18 patients to whom ICG Rmax test was requested, ICG Rmax test was carried out at two doses of 0.5 mg/kg and 5 mg/kg and MEGX formation after 15 minute of 1 mg/kg lidocaine Injection was measured by fluorescence polarization immunoassay (FPIA) method. The correlation between them was analyzed, To 25 healthy volunteers included in this study as normal control, lidocaine was given intravenously at, a dose of 1 mg/kg and MEGX forma pion was measured IS and 30 minute later (MEGX15, MEGX30) using both high performance liquid chromatography (HPLC) and FPIA methods. RESULT: Patient group resealed significant correlation between ICG Rmax and MEGX15 (r=0.7674, p<0.001) and also between ICG Rl5 and MEGX15 (r=0.5612, p=0.008). There was significant difference between MEGX15 of 9 patients with chronic liver diseases and those of normal controls (22.24+/- 13.18 and 35.40+/- 14.43 ng/mL, respectively) (p=0.01). In normal controls, the correlation between methods was significant (p=0.001) and the values measured by FPIA method was significantly higher than that by HPLG (p(0.001). Of the normal controls, male group had higher MEGX15 values than female group in both methods (in HPLC method 33.89+/-15.95 and 22.53+/- 8.36, and in FPIA method 41.48+/-16.61 and 28.81+/-7.88 ng/mL, respectively), and in female group MEGX30 values was significantly elevated compared to MEGX15 (p<0.001). CONCLUSION: Inferred from the fact that the correlation between ICG Rmax and MEGX was good, MEGX test can be considered a replacement for ICG Rmax. In healthy adults, it is considered that there is serf-related difference In the rate of lidocaine metabolism so we should pay attention to it in interpreting the MEGX results.