Clinical Abstracts
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November 2012 Editor:
Massive transfusion protocols and the optimal ratio of blood components for maximum benefit to trauma patients is a highly debated topic. Recent studies explored whether a 1:1 ratio of red blood cells (RBC) to fresh frozen plasma (FFP) constitutes the best strategy for improved outcomes following acute traumatic coagulopathy. Other components, such as platelets and cryoprecipitate, are included in some studies for their role in reversing traumatic blood loss. And off-label uses for factors such as Factor VII (rFVIIa) are used by trauma programs for massive and uncontrolled blood loss. The authors conducted a study to evaluate the use of rFVIIa in trauma patients following the use of a 1:1 or 1:2 RBC/FFP ratio during massive transfusions. They performed a retrospective analysis to determine utilization of their newly created massive transfusion protocol and to track the timely receipt of blood bank specimens sent to the lab. The authors reviewed the records from 49 trauma patients who received at least 10 units of packed RBCs in a 24-hour period and compared the records with a historic massively transfused cohort. They examined the outcome variables of mortality, length of intensive care unit stay, number of ventilator days, and 24-hour blood component use. The results showed that the cohort with the 1:1 or 1:2 ratio of RBC/FFP used fewer blood components and did not require rescue with rFVIIa compared to the historic cohort. Furthermore, the historic rFVIIa cohort showed a trend toward longer hospital stays, more days in the intensive care unit, and more days on the ventilator, but these outcomes did not reach statistical significance. The authors concluded that lower blood component use and avoidance of rFVIIa use led to an overall cost savings of $13,270 per massive transfusion protocol patient. Tan JNM, Burke PA, Agarwal SK, et al. A massive transfusion protocol incorporating a higher FFP/RBC ratio is associated with decreased use of recombinant activated factor VII in trauma patients. Am J Clin Pathol. 2012;137:566–571. Correspondence: Dr. Josenia Tan, Dept. of Pathology and Laboratory Medicine, Boston University Medical Center, 1 Boston Medical Center Place, Boston, MA 02118 [ Top ]
Acceptable blood lead levels by national standards are less than 1.21 µmol/L (less than 25 µg/dL). Lead toxicity is associated with gouty arthritis, but it is not known if low-level lead exposure is associated with risk of gout. Lead toxicity is associated with hyperuricemia and gout through increased production or decreased excretion of uric acid. The acceptable ranges of blood lead levels defined by the Centers for Disease Control and Prevention may not represent the true incidence of harm from lead exposure since these ranges were shown to be associated with cardiovascular mortality and chronic kidney disease progression. The authors conducted an observational population-based cross-sectional study to determine if lower levels of blood lead are associated with gout. They used data from the National Health and Nutrition Examination Survey from 2005 to 2008. The population, which ranged in age from 40 to 85 years, represented a demographically diverse cohort selected to represent national statistics. The authors collected and analyzed data on levels of serum creatinine and heavy metals in blood, as well as serum urate concentration. They found that the study population with the highest quartile of blood lead level had an odds ratio of 3.62 (95 percent confidence interval [CI], 2.10–6.25) for gout and 1.85 (CI, 1.34–2.56) for hyperuricemia. The authors concluded that blood lead levels as low as 0.06 µmol/L (1.2 µg/dL) may be associated with an increased prevalence of gout independent of other factors. They noted that a limitation of the study is the method of blood lead measurement, which is less sensitive than other tests, including bone lead measurement. However, this study still has implications for examining the current standards for acceptable blood lead levels, which may impact environmental sources of exposure and prompt clinicians to measure blood lead levels when a secondary cause of gout is suspected. Krishnan E, Lingala B, Bhalla V. Low-level lead exposure and the prevalence of gout: an observational study. Ann Intern Med. 2012;157:233–241. Correspondence: Dr. Eswar Krishnan, Stanford University School of Medicine, 1000 Welch Rd., Suite 203, Palo Alto, CA 94304 [ Top ]
Adults can lower their blood pressure by eating dark chocolate on a regular basis. Antioxidants in the cocoa improve endovascular function and increase bioactive nitric oxide. Because higher blood pressure strongly predicts cardiovascular disease, maintaining lower blood pressure starting in childhood may prevent this disease later in life. The benefits of dark chocolate intake are not well known in children. Most children have blood pressure in the normal range, so a nonpharmacological intervention like chocolate may have increasing benefits. The authors performed a randomized intervention study involving 194 children to examine the feasibility of distributing dark chocolate at school and to study its short-term effect in reducing the children’s mean group blood pressure. They also assessed how eating dark chocolate could possibly harm the children’s body mass index, body fat, health-related quality of life, body satisfaction, and self-perception. For the study, children were randomized by class to receive dark chocolate (7 g daily before lunch) or no intervention. The two groups were similar with respect to outcome measurements, and both groups showed little evidence of negative effects on any measure of anthropometry or well-being. However, the intervention students reported a slightly higher score for body dissatisfaction. The authors noted that their small trial did not show evidence that dark chocolate offers a short-term benefit to blood pressure in healthy children. However, they recommend a larger, longer trial or higher daily doses of chocolate, or both, to detect effects. The authors also noted that this study proved the feasibility of performing this type of intervention in school-age children. They concluded that more data are needed to assess if a dark chocolate supplement has benefit for lowering children’s blood pressure and preventing untoward effects of cardiovascular disease later in life. Chan EK, Quach J, Mensah FK, et al. Dark chocolate for children’s blood pressure: randomised trial. Arch Dis Child. 2012;97:637–640. Correspondence: Melissa Wake at melissa.wake@rch.org.au [ Top ]Clinical pathology abstracts editor: Deborah Sesok-Pizzini, MD, MBA, associate professor, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, and medical director, Blood Bank and Transfusion Medicine, Children’s Hospital of Philadelphia. |
