Feng Chang Lin

Acupuncture sensation during ultrasound guided acupuncture needling

Background Although acupuncture sensation (also known as de qi) is a cornerstone of traditional acupuncture therapy, most research has accepted the traditional method of defining acupuncture sensation only through subjective patient reports rather than on any quantifiable physiological basis. Purpose To preliminarily investigate the frequency of key sensations experienced while needling to specific, quantifiable tissue levels (TLs) guided by ultrasound (US) imaging. Methods Five participants received needling at two acupuncture points and two control points at four TLs. US scans were used to determine when each TL was reached. Each volunteer completed 32 sets of modified Southampton Needle Sensation Questionnaires. Part one of the study tested sensations experienced at each TL and part two compared the effect of oscillation alone versus oscillation + rotation. Results In all volunteers, the frequency of pricking, sharp sensations was significantly greater in shallower TLs than deeper (p=0.007); the frequency of sensations described as deep, dull and heavy, as spreading, and as electric shocks was significantly greater in deeper TLs than shallower (p=0.002). Sensations experienced did not significantly differ between real and control points within each of three TLs (p>0.05) except TL 4 (p=0.006). The introduction of needle rotation significantly increased deep, dull, heavy sensations, but not pricking and sharp sensations; within each level, the spectrum of sensation experienced during both oscillation + rotation and oscillation alone did not significantly differ between acupuncture and control points. Conclusion The preliminary study indicates a strong connection between acupuncture sensation and both tissue depth and needle rotation. Furthermore, the new methodology has been proven feasible. A further study with an objective measurement is warranted.

Composite variables: when and how.

Background:Use of composite variables is a common practice, but knowledge about what researchers should consider when creating composite variables is lacking. Objective:The purpose of this paper was to present methods used to create composite variables with attention to advantages and disadvantages. Methods:Methods of simple averaging, weighted averaging, and meaningful grouping to create composite variables are described briefly, and the context in which one method might be more suitable than the others is discussed. Study examples and comparisons of statistical power among these methods as well as Bonferroni correction are described. Discussion:Each approach to creating composite variables has advantages and disadvantages that researchers should weigh carefully. With normally distributed data, composite variables provide the greatest increases in power when the original variables (that make up the composite variable) have similar associations with the outside outcome variable.

Procoagulant Microparticles Promote Coagulation in a Factor XI-Dependent Manner in Human Endotoxemia

Essentials The procoagulant effects of microparticles (MPs) on coagulation in endotoxemia are not known. MPs from endotoxemia volunteers were evaluated for procoagulant activity in a plasma milieu. MPs from endotoxemia volunteers shortened clotting times and enhanced thrombin generation. MP procoagulant effects were mediated in a factor XI‐dependent manner.

Bleeding risk in warfarinized patients with a therapeutic international normalized ratio: the effect of low factor IX levels.

Bleeding is the main complication of warfarin therapy, even patients with an international normalized ratio (INR) in the target range can suffer bleeding, suggesting that INR does not perfectly reflect the therapeutic effect of warfarin. We hypothesized the INR might underestimate the level of anticoagulation in a subject with a lower factor (F) IX level than average.

The fibrinogen γA/γ’ isoform does not promote acute arterial thrombosis in mice

Elevated plasma fibrinogen is associated with arterial thrombosis in humans and promotes thrombosis in mice by increasing fibrin formation and thrombus fibrin content. Fibrinogen is composed of six polypeptide chains: (Aα, Bβ, and γ)2. Alternative splicing of the γ chain leads to a dominant form (γA/γA) and a minor species (γA/γ′). Epidemiological studies have detected elevated γA/γ′ fibrinogen in patients with arterial thrombosis, suggesting that this isoform promotes thrombosis. However, in vitro data show that γA/γ′ is anticoagulant due to its ability to sequester thrombin and suggest its expression is upregulated in response to inflammatory processes.

Blood utilization in patients with burn injury and association with clinical outcomes (CME)

Uncontrolled bleeding is an important cause of increased transfusion in burn victims; however, description of blood utilization patterns in the burn population is lacking.

Major Burn Injury is not Associated with Acute Traumatic Coagulopathy

BACKGROUND The pathophysiology and time course of coagulopathy after major burns are inadequately understood. Our study objectives were to determine whether acute traumatic coagulopathy (ATC) is seen in burn patients at admission and to determine the changes in international normalized ratio (INR), activated partial thromboplastin time (aPTT), platelet count (PLT), and hemoglobin (Hgb) in the first 7 days after injury. METHODS We conducted a retrospective study of patients with burn injury of at least 15% total body surface area who presented to the University of North Carolina. Data on patient demographics, injury characteristics, and laboratory data (INR, aPTT, PLT, and Hgb) at admission and within the first 7 days after injury were recorded. We defined ATC as INR of 1.3 or greater, aPTT of 1.5 or greater times the mean normal limit, and normal PLT at admission. RESULTS We studied the hematologic profile of 102 patients with burn injury of 15% to 100% total body surface area but did not identify a single patient with ATC at admission. The screening hematologic profile at admission was not influenced by burn severity. In the first 7 days after injury, the INR and aPTT were relatively preserved, while the PLT quickly recovered to baseline after an early decline and the Hgb remained stable at around 10 g/dL; all these changes occurred during the time when the burn patients had received large amounts of fluid resuscitation. CONCLUSION The screening hematologic profile of burn patients at admission is normal, and the standard screening assays do not suggest the existence of ATC at admission. While this is a relatively small study, it provides evidence to suggest that ATC is unique to trauma patients. LEVEL OF EVIDENCE Prognostic study, level III.

Prophylactic efficacy of BeneFIX vs Alprolix in hemophilia B mice

FIX binds tightly to collagen IV. Furthermore, a FIX mutant, FIXK5R, which binds better than wild-type FIX to collagen IV, provides better hemostasis than wild-type FIX, long after both are undetectable in the plasma. There is also credible evidence of extravascular FIX. Here, we use the saphenous vein bleeding model to compare the efficacy of recombinant FIXFc (Alprolix) and wild-type FIX (BeneFIX) in hemophilia B mice 7 days postinfusion. Although the terminal half-life of Alprolix is significantly longer than that of BeneFIX, at equal doses Alprolix is not better at controlling bleeding 7 days postinfusion, presumably because of the extravascular FIX. Both BeneFIX and Alprolix exhibit a linear response in clotting efficacy up to 150 IU/kg, where they appear to saturate an extravascular compartment, because there is no additional prophylactic benefit from higher doses. A robust pool of extravascular FIX is clearly observed surrounding blood vessels, localized to the same region as collagen IV, in 2 representative human tissues: liver and skeletal muscle. We see no increased risk for thrombosis at 250 IU/kg FIX at 6 hours postinfusion. In summary, 7 days postinfusion into hemophilia B mice, BeneFIX and Alprolix are hemostatically indistinguishable despite the latters increased half-life. We predict that doses of FIX ∼3 times higher than the currently recommended 40 to 50 IU/kg will, because of FIXs large extravascular compartment, efficiently prolong prophylactic hemostasis without thrombotic risk.

Estimated incidence and risk factors of sudden unexpected death

Objective In this manuscript, we estimate the incidence and identify risk factors for sudden unexpected death in a socioeconomically and racially diverse population in one county in North Carolina. Estimates of the incidence and risk factors contributing to sudden death vary widely. The Sudden Unexpected Death in North Carolina (SUDDEN) project is a population-based investigation of the incidence and potential causes of sudden death. Methods From 3 March 2013 to 2 March 2014, all out-of-hospital deaths in Wake County, North Carolina, were screened to identify presumed sudden unexpected death among free-living residents between the ages of 18 and 64 years. Death certificate, public and medical records were reviewed and adjudicated to confirm sudden unexpected death cases. Results Following adjudication, 190 sudden unexpected deaths including 122 men and 68 women were identified. Estimated incidence was 32.1 per 100 000 person-years overall: 42.7 among men and 22.4 among women. The majority of victims were white, unmarried men over age 55 years, with unwitnessed deaths at home. Hypertension and dyslipidaemia were common in men and women. African-American women dying from sudden unexpected death were over-represented. Women who were under age 55 years with coronary disease accounted for over half of female participants with coronary artery disease. Conclusions The overall estimated incidence of sudden unexpected death may account for approximately 10% of all deaths classified as ‘natural’. Women have a lower estimated incidence of sudden unexpected death than men. However, we found no major differences in age or comorbidities between men and women. African-Americans and young women with coronary disease are at risk for sudden unexpected death.

Relation of Household Income to Incidence of Sudden Unexpected Death in Wake County, North Carolina

The incidence of out-of-hospital sudden unexpected death (OHSUD) in a racially and socioeconomically diverse population has been inadequately studied. We collated all OHSUDs over a 24-month period among 18- to 64-year olds in Wake County, North Carolina, to investigate geographic and socioeconomic disparity in incidence of OHSUD. An electronic query of Wake County Emergency Medical Services (EMS) identified all EMS attended out-of-hospital deaths. After excluding trauma, expected deaths, and deaths occurring in non-free-living subjects, medical records and medical examiners reports were reviewed by a committee of cardiologists to make the determination of OHSUD. Victims were geocoded to census tracts, and demographic and socioeconomic data were obtained from the 2014 American Community Survey and 2010 US Census. Incidence was examined by sociodemographic group with univariate analysis and multivariable regression. There were 397 OHSUDs, and 53% of census tracts had >1 event. The incidence of OHSUD was 64 of 100,000; 107 of 100,000 among blacks; and 60 of 100,000 among whites. Census tracts with >1 OHSUD had a higher population of blacks, a greater proportion unmarried, a lower median household income, and a greater proportion residing in a rural area. Only median household income remained a significant predictor of OHSUD after adjustment in multivariable analysis. Low median household income of a community portends a higher incidence of sudden death. In conclusion, interventions to reduce the incidence of sudden death need to be developed with these specific communities in mind.