Background and aims There is limited information on reference values for lipids and lipoproteins in an Irish population. In this observational study, we have described the distributions of lipids in a large Irish cohort. Methods Over 110,000 lipid profiles were selected from a database of almost 1.5 million consecutive lipid profiles performed in the Clinical Biochemistry Laboratory in University Hospital Galway between 2004 and 2017 to best represent the Irish population. Age- and sex-related reference intervals for both sexes for total cholesterol, triglycerides, HDL cholesterol and LDL cholesterol, from the age of ten to greater than 90 years, were determined. Two methods for estimating LDL cholesterol were also compared. Results Sex-related differences in lipid distributions arise before the age of 20 years and are life-long. In both sexes total and LDL cholesterol levels gradually increased towards middle age with a decrease towards old age. Levels tended to be higher in males than in females up to mid-life at which stage they cross over with females having on average higher levels. The median of the triglyceride distributions show similar age- and sex-related changes to total cholesterol, but the distributions show a very marked positive skew that is particularly obvious in middle aged males. HDL cholesterol distributions change little throughout life with males having lower levels than females. Changing from the Friedewald formula to that proposed by Martin would impact the management of some patients with dyslipidaemia. Conclusions This study provides lipid reference values for clinical biochemistry laboratories and clinicians working in Ireland. It is informative for public health initiatives wishing to target dyslipidaemia as a modifiable risk for cardiovascular disease and for investigators researching geographical and temporal variances in lipid parameters.

DISTRICT & COUNTY PRESIDENTS Geoffrey R. Hamilton, MD Bristol County Medical Society Herbert J. Brennan, DO Kent County Medical Society Jayanthi Parameswaran, MD Newport County Medical Society Martin R. Papazian, MD Pawtucket Medical Association Patrick J. Sweeney, MD, PhD, MPH Providence Medical Association Nitin S. Damie, MD Washington County Medical Society Naeem M. Siddiqi, MD Woonsocket District Medical Society RHODEISLAND Medicine Health 

DISTRICT & COUNTY PRESIDENTS Pamela A. Harrop, MD Bristol County Medical Society Gary A. L’Europa, MD Kent County Medical Society Jayanthi Parameswaran, MD Newport County Medical Society Stephen T. Conway, MD Pawtucket Medical Association Patrick J. Sweeney, MD, PhD, MPH Providence Medical Association R. Scott Hanson, MD Washington County Medical Society Naeem M. Siddiqi, MD Woonsocket District Medical Society RHODEISLAND Medicine Health

BACKGROUND: Preoperative bleeding time (BT) does not correlate with postoperative bleeding in patients subjected to surgical procedures. A significant positive correlation has been reported between the BT 2 hours after cardiopulmonary bypass surgery and the nonsurgical blood loss during the first 4 hours after bypass surgery. This study was done to investigate the effect of Hct and platelet count on the BT measurement in normal, healthy men and women.STUDY DESIGN AND METHODS: To assess the relative effect of RBCs and platelets on the BT, 22 healthy male and 7 healthy female volunteers were subjected to the removal of 2 units of RBCs (360 mL), followed by the return of the platelet‐rich plasma (PRP) from both units and the infusion of 1000 mL of 0.9‐percent NaCl. Four of the men and all seven women received their RBCs 1 hour after their removal. Shed blood levels of thromboxane B2 (TXB2), 6‐keto prostaglandin F1α, and peripheral venous Hct were measured. BTs were measured in 15 men and 13 women before and after a plateletpheresis procedure to collect 3.6 × 1011 platelets per unit.RESULTS: The 2‐unit RBC apheresis procedure produced a 60‐percent increase in the BT associated with a 15‐percent reduction in the peripheral venous Hct and a 9‐percent reduction in the platelet count. The plateletpheresis procedure produced a 32‐percent decrease in the platelet count, no change in peripheral venous Hct, and no change in the BT. After the removal of 2 units of RBCs, the shed blood TXB2 level decreased significantly. Reinfusion of 2 units of RBCs restored the BT and restored the TXB2 level to the baseline levels.CONCLUSION: The acute reduction in Hct produced a reversible platelet dysfunction manifested by an increase in BT and a decrease in the shed blood TXB2 level at the template BT site. Return of the RBCs restored both the BT and the shed blood TXB2 level to normal. The platelet dysfunction observed with the reduction in Hct was due in part to a reduction in shed blood TXB2 and other, unknown mechanisms.

“This study considers the nature of medieval literary authority, and the ways in which it has been constructed in several important medieval and non-medieval texts and contexts. Most of the editorial and critical work with medieval manuscripts has operated under the assumption of a single, static, and non-historicized authority behind each text, but literary authority is always potentially diffuse. Works we currently know in more than one version receive the majority of attention here, because they show in a very tangible way the results of dynamic interaction among authors, audiences, and other agents of literary production and consumption.

The benefits of a Hct range of 30 to 35 percent include improved oxygen delivery and enhanced hemostasis, which help minimize complications in patients at high risk for ischemia and perioperative nonsurgical bleeding. In these settings, the conservative transfusion practice of using a lower Hct range should be replaced with a more aggressive approach. The known risks of blood transfusion would appear to be sufficiently low and the benefits sufficiently high to justify maintaining a Hct of at least 30 percent. An even higher Hct, of 35 percent, may be desirable in patients who have overt cardiopulmonary disease or who are at high risk for myocardial ischemia. Many retrospective studies have been conducted to persuade us that a conservative transfusion trigger is a safe and prudent practice, but retrospective studies are not what we need. What we need is a series of well-designed, prospective, randomized trials to evaluate the impact of a more aggressive transfusion policy on perioperative mortality, morbidity, and nonsurgical bleeding in patients with known cardiopulmonary disease or who are at high risk for myocardial and cerebrovascular ischemia.