The impact of prehospital blood sampling on the emergency department process of patients with chest pain:a pragmatic non-randomized controlled trial

BACKGROUND:In patients with chest pain who arrive at the emergency department(ED)by ambulance,venous access is frequently established prehospital,and could be utilized to sample blood.Prehospital blood sampling may save time in the diagnostic process.In this study,the association of prehospital blood draw with blood sample arrival times,troponin turnaround times,and ED length of stay(LOS),number of blood sample mix-ups and blood sample quality were assessed.METHODS:The study was conducted from October 1,2019 to February 29,2020.In patients who were transported to the ED with acute chest pain with low suspicion for acute coronary syndrome(ACS),outcomes were compared between cases,in whom prehospital blood draw was performed,and controls,in whom blood was drawn at the ED.Regression analyses were used to assess the association of prehospital blood draw with the time intervals.RESULTS:Prehospital blood draw was performed in 100 patients.In 406 patients,blood draw was performed at the ED.Prehospital blood draw was independently associated with shorter blood sample arrival times,shorter troponin turnaround times and decreased LOS(P<0.001).No differences in the number of blood sample mix-ups and quality were observed(P>0.05).CONCLUSION:For patients with acute chest pain with low suspicion for ACS,prehospital blood sampling is associated with shorter time intervals,while there were no significant differences between the two groups in the validity of the blood samples.

Accurate laser skin perforation technique aimed at promoting bleeding and reducing pain

Laser skin perforation is an effective and promising technique for use in blood collection.In this study,the relation between the perforation profile of skin and laser irradiation at various energies is discussed.Increasing laser energy does not uniformly expand the size and depth of a hole because the shallow depth of field(DOF)of the focused light primarily concentrates energy on the skin surface.In practice,the hole gradually transforms from a semielliptical shape to an upsidedown avocado shape as the laser energy increases.This phenomenon can increase the amount of bleeding and reduce pain.The findings support the feasibility of developing an accurate laser skin perforation method.

Blood collection procedures influence contamination rates in blood culture： a prospective study

Background Blood culture contamination is a significant adverse event. The aim of this project was to evaluate the efficacy of a strict blood collection procedure in reducing the blood culture contamination rate. Methods A prospectively controlled study was performed in two different medical areas in Peking Union Medical College Hospital （PUMCH） for 16 months （from May 2006 to September 2007）. In test group, a strict blood collection procedure was carried out by trained nurses with the veinpuncture sites were scrupulously disinfected with 2.5% tincture of iodine plus 70% alcohol. In control group, commonly used procedure in PUMCH was performed with 0.45% chlorhexidine acetate plus 0.2% iodine. Blood culture positive results for 4 target organisms （Coagulase-negafive staphylococci, Propionibacterium acnes, physicians from infectious department to （contamination）. Corynebacterium species and Bacillus determine whether a sample was true species） were further assessed by positive （pathogen） or false positive Results Total 9321 blood culture collections were analyzed. The blood culture contamination rate in test group was significantly lower than that in control group （5/3177 （0.16%） vs. 77/6144 （1.25%）; x2=13.382, P 〈0.001）. The most common contaminant was Coagulase-negative staphylococcus （76.83%）. The average cultural time during which contaminated samples became positive was longer than that for true pathogen samples （42.0 hours vs. 13.9 hours, P=-0.041）. Conclusion Using a strict blood collection procedure can significantly reduce blood culture contamination rate.

Prenatal cytogenetic diagnosis study of 2782 cases of high-risk pregnant women

Background Prenatal diagnoses are extremely advantageous for pregnant women with high-risk indicators and can help prevent the birth of malformed infants. However, no large-scale statistical study analyzing the correlation between fetal chromosome disorders and abnormal indicators during pregnancy has been done in China. The objectives of this study were to diagnose and analyze fetal chromosome abnormalities, determine the feasibility of the various prenatal test methods and establish diagnostic guidelines for the early, middle, and late trimesters. Methods From January 2004 to May 2009, 2782 pregnant women at high-risk underwent prenatal diagnoses. Categorized data expressed as either actual counts or percentages were analyzed by the chi-square or Fisher＇s exact test. Chorionic villus sampling was performed in the early-trimester （10-12 weeks of gestation）, amniocentesis in mid-trimester （16-28 weeks of gestation）, and umbilical cord blood collection in mid- or late-trimester （16-37 weeks of gestation）. In 51 cases either autopsy samples from intrauterine fetal deaths or placental tissues from aborted fetuses were tested. Results Chromosomal abnormalities were observed in 3.99% （111/2782） of the samples. Overall, the success rate of cytogenetic analysis for high-risk pregnancy groups was 98.17% （2731/2782）. It was significantly less successful when used to analyze data from the chorionic villus sampling compared with that from amniocentesis and umbilical cord blood （P=-0.000）. Abnormal chromosome carriers had the highest percentage of abnormal chromosomes （67.86%） when compared with chromosomal abnormalities in patients with ultra-sonographic ＂soft markers＂ （11.81%）, advanced maternal age （4.51%） and those who had positive serum screening results （P=-0.000）. Conclusions Invasive prenatal diagnostic techniques are feasible tools for confirming fetal chromosomal abnormalities. Abnormal chromosomes detected in one of the parents carrying abnormal chromosome, ultrasound soft markers, advanced maternal age or positive serum screening results were associated with a higher frequency of fetal genetic diseases.