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Biomedical subjects

L B Roberts

Publications and source records attributed to L B Roberts.

16 recordsLinked to original sources
PubMed1982

Effect of favourable treatment of samples on indices of performance in external quality assessment schemes.

This study was carried out to examine the effect on performance, as assessed by external quality assessment schemes, of (a) replicate analysis of external quality assessment samples, and positioning of external quality assessment samples immediately after the calibrants, and (b) alteration of results on the basis of previous performance in order to bring them closer to the method mean values obtained from all laboratories participating in the external quality assessment scheme. Indices of performance were then compared with those obtained from our normal practice where external quality assessment samples were treated as patient samples. Using these methods we were unable to improve significantly our precision or league ranking based on precision over the six-month period of study. We were able to reduce our bias from method means but at the expense of making precision and league ranking worse.

Chemistry, Clinical↗
PubMed1981

The amylase-creatinine clearance ratio following cardiopulmonary bypass.

The incidence of unexplained pancreatitis in patients dying after cardiac operations has been recorded as 16%, with evidence to implicate ischemia in the pathogenesis of the pancreatitis. Increased amylase--to--creatinine clearance ratios (ACCR), suggesting pancreatic dysfunction, have been reported in patients following nonpulsatile cardiopulmonary bypass (CPB). Pulsatile CPB is increasingly recognized to be a more physiological form of perfusion, particularly with respect to capillary blood flow. In this study the ACCR has been determined before, during, and after cardiac operations performed with both nonpulsatile and pulsatile CPB. Twenty patients undergoing elective cardiac operations were studied. Ten patients had nonpulsatile CPB (nonpulsatile group) and 10 had pulsatile CPB (pulsatile group). The two groups were comparable as regards perioperative variables and perfusion parameters. In both groups the ACCR was estimated preoperatively, on three occasions during the operation, and daily on the first 5 postoperative days. A significant elevation in ACCR was observed in nine of 10 patients in the nonpulsatile group but in only one of 10 patients in the pulsatile group (p less than 0.001). The significant improvement of ACCR stability following pulsatile CPB may indicate that this form of perfusion will reduce the risk of pancreatitis following cardiac operations performed with CPB.

Adult↗
PubMed1978

An evaluation of the Jeol Clinalyzer.

The Jeol Clinalyzer was evaluated over a period of 15 weeks. The operating principles are briefly described. The functions of the mechanical components were tested and assessments made of the instrument's safety and reliability. The mechanical and electrical reliability of the instrument was excellent and the pumps and spectrophotometer gave good accuracy and precision. Between-batch precision of the analytical methods was good for urea, protein and bilirubin and acceptable for alkaline phosphatase and aspartate transaminase. There was a poor relative accuracy for alkaline phosphatase and aspartate transaminase and some proportional inaccuracy for urea and bilirubin.

Alkaline Phosphatase↗