Peggy Mann

Effects of aluminum on the liver following high-dose enteral administration to rats.

Parenteral administration of aluminum (Al) to animals can result in hepatobiliary dysfunction, including elevated total serum bile acid concentration, reduced bile flow, and reduction of mixed function oxidase activities. Despite substantial hepatic Al accumulation, biliary Al excretion is negligible. We studied the effects of enteral administration of pharmacologic doses of Al to rats in order to see if by this route Al also produced hepatobiliary dysfunction or if biliary Al excretion was enhanced following enteral administration, protecting the liver from the effects of Al. Six rats were given 100 mg/kg/day of Al for 14 days as Al citrate by duodenal cannula. Pair-fed littermate controls were given sodium citrate. Serum Al and urinary Al/creatinine were significantly higher in Al-fed rats than in controls. Liver Al was significantly increased in the Al-fed group, but very low when compared to liver Al concentration with intravenous Al administration. Biliary Al was only 2 +/- 1% of urinary Al in the experimental group. Serum bile acid concentration and bile flow were not different between groups. We conclude that Al given in pharmacologic doses is absorbed but does not accumulate in the liver. We hypothesize that a slow rate of Al absorption may not overwhelm plasma transferrin carrying capacity or renal Al excretory capacity.

POCT PT INR — Is it adequate for patient care? A comparison of the Roche Coaguchek XS vs. Stago Star vs. Siemens BCS in patients routinely seen in an anticoagulation clinic

BACKGROUND In this study we examined the difference in patient INR values as measured by the POCT CoaguChek XS device and central laboratory Stago Evolution and Siemens BCS XP analyzers. METHODS This study composed of 100 warfarin therapy patients and 20 coagulation normal subjects, showed that the difference between the POCT and clinical laboratory values increased with increasing INR and was exacerbated by the use of different thromboplastin reagents by the POCT and central lab. RESULTS The CoaguChek XS and on-site Stago analyzers which used human recombinant (ISI=1.01) and rabbit brain thromboplastin (ISI=1.25), respectively, showed reasonable agreement for INR<3.0 (k=0.62) but significant difference for INR≥3.0 (k=0.10). In contrast, the CoaguChek XS and Siemens BCS XP, which both employed human recombinant thromboplastin (BCS ISI=1.02), showed greater agreement for the complete range INR values (INR<3.0 k=0.84; INR≥3.0 k=0.70). ECAA Poller calibrant data showed the automated instruments were performing as expected, indicating that ISI calibrations were correct but insufficient to standardize the INR values for the different thromboplastin methods across the full range of measured INRs. Central lab verification of POCT INR>5.0 with the Stago Evolution prevented adverse treatment events for the warfarin therapy patients in the six months preceding and following this investigation.

Data documenting the performance of the PT/INR line correction method for reconciling INR discrepancies between central laboratory coagulation analyzers using different thromboplastins during the evaluation of a portable Coagulometer

The data presented here was produced as part of an evaluation of the performance of the CoaguChek XS point-of-care coagulation analyzer, which is discussed in the research article “POCT PT INR – Is it adequate for Patient Care? A Comparison of the Roche Coaguchek XS vs. Stago Star vs. Siemens BCS in Patients Routinely Seen in an Anticoagulation Clinic” (Baker et al., in press) [1]. An effort to reconcile discrepancies in the patient INR result distributions from different central lab instruments (Stago Star and Siemens BCS) with the PT/INR line method is described (Poller et al., 2010, 2011; Ibrahim et al., 2011) [2], [3], [4]. While regression analysis of the ECAA Poller calibrant data provided a linear PT/INR line for all methods, Pearsons chi-squared and one-way repeated measures ANOVA analyses showed that central lab INR measurements continued to exhibit measurement site dependence after the PT/INR line correction was applied. According to paired t-test analysis, only the human thromboplastin dependent methods (CoaguChek XS and Siemens BCS both before and after PT/INR line correction) showed statistically significant agreement (p-value >0.05).

Hurricanes: Are You Prepared?

Severe weather events such as hurricanes have the potential to cause significant disruption of laboratory operations. Comprehensive planning is essential to mitigate the impact of such events. The essential elements of a Hurricane Plan, based on our personal experiences, are detailed in this article.

What’s a Lab to Do During and After a Hurricane?

Although laboratories may be able to rely on a comprehensive Hurricane Plan during a hurricane, alarming and unanticipated events frequently occur. To minimize disruption of lab operations, it is important to try to mitigate the impact of these unexpected events as quickly as possible, in the quest to minimize negative outcomes. In this article, we discuss approaches to dealing with unanticipated events during and after hurricanes, based on our personal experiences.