Perioperative management of clopidogrel therapy: the effects on in-hospital cardiac morbidity in older patients with hip fractures.

BACKGROUND: Increasing numbers of older patients prescribed clopidogrel are presenting for urgent hip fracture surgery. Best practice for the management of clopidogrel therapy is unknown, although delays to surgery are associated with increased mortality. We investigated the influence of perioperative management of clopidogrel therapy on in-hospital cardiac morbidity and transfusion in this population. METHODS: Retrospective review of all patients aged >60 yr, admitted to a single centre with hip fractures between June 2005 and November 2008. Acute coronary syndrome (ACS) was defined as a raised plasma troponin concentration >0.04 µg litre(-1) associated with chest pain, new ECG changes, or both. RESULTS: Of 1381 patients admitted with hip fractures, 114 were receiving regular clopidogrel therapy with a median age of 83.7 (60-98) yr. Clopidogrel was withheld perioperatively in 111 (98%) of these patients. Twenty-three patients (20.2%) suffered an ACS. Risk peaked for ACS [odds ratio (OR) 6.7 (95% confidence interval, CI, 1.7-25.8)] (P=0.006) between days 4 and 8 after clopidogrel withdrawal. The OR for requiring a blood transfusion during or after surgery peaked at day 1 after clopidogrel withdrawal [OR 2.31 (95% CI, 1.02-5.21)] (P=0.044). CONCLUSIONS: The length of withdrawal of clopidogrel therapy perioperatively was associated with a significantly increased incidence of ACS. An association between shorter withdrawal and increased blood transfusion requirements was also seen. The study emphasizes the cardiovascular risks of routinely interrupting clopidogrel therapy in this at-risk population and that a more considered, individualized, evidenced-based approach is needed.

Influence of postexercise glucose ingestion upon serum potassium levels and ECG function.

Thirteen trained runners were studied to determine whether postexercise glucose ingestion contributes to electrocardiogram (ECG) alterations by enhancing decreases in serum potassium (K+) concentrations. For the two randomly ordered trials, subjects ingested a 100 g (25% w/v glucose polymer) drink, either alone or with the addition of 3 g of potassium chloride (KCl), within 15 min following a 90-min run. ECG parameters, serum K+, and glucose concentrations were measured preexercise (Time 0), 2-3 min post-exercise (Time 1), and 25 (Time 2) and 60 (Time 3) min postexercise. The data suggest that postexercise glucose ingestion may cause ECG changes that are not directly related to the return of K+ to muscle, and that these changes, although characteristic of hypokalemia, may be related to serum glucose excursions rather than to absolute levels of serum K+. The addition of KCl may have prevented these changes by delaying gastric emptying of glucose.

Reproductive and vegetative morphology of a cretaceous angiosperm.

Recent collections from plant-bearing deposits of Cenomanian age in central Kansas have yielded angiosperm axes with helically arranged, seed-bearing, conduplicate carpels. Large leaves associated with these fruits are thought to represent parts of the same kind of plant because the leaves and fruits are the only plant fossils at this locality to have distinctive, morphologically identical, yellow bodies within their carbonaceous remains. These fossils provide a rare opportunity to study the morphology of an ancient angiosperm and illustrate the antiquity of certain features considered primitive by comparative angiosperm morphologists.