A simple and novel equation to estimate the degree of bleeding in haemorrhagic shock: mathematical derivation and preliminary in vivo validation

Determining blood loss [100% – RBV (%)] is challenging in the management of haemorrhagic shock. We derived an equation estimating RBV (%) via serial haematocrits (Hct1 , Hct2 ) by fixing infused crystalloid fluid volume (N) as [0.015 × body weight (g)]. Then, we validated it in vivo. Mathematically, the following estimation equation was derived: RBV (%) = 24k / [(Hct1 / Hct2 ) – 1]. For validation, nonongoing haemorrhagic shock was induced in Sprague–Dawley rats by withdrawing 20.0%–60.0% of their total blood volume (TBV) in 5.0% intervals (n = 9). Hct1 was checked after 10 min and normal saline N cc was infused over 10 min. Hct 2 was checked five minutes later. We applied a linear equation to explain RBV (%) with 1 / [(Hct1 / Hct2 ) – 1]. Seven rats losing 30.0%–60.0% of their TBV suffered shock persistently. For them, RBV (%) was updated as 5.67 / [(Hct1 / Hct2 ) – 1] + 32.8 (95% confidence interval [CI] of the slope: 3.14–8.21, p = 0.002, R2 = 0.87). On a Bland-Altman plot, the difference between the estimated and actual RBV was 0.00 ± 4.03%; the 95% CIs of the limits of agreements were included within the pre-determined criterion of validation (< 20%). For rats suffering from persistent, non-ongoing haemorrhagic shock, we derived and validated a simple equation estimating RBV (%). This enables the calculation of blood loss via information on serial haematocrits under a fixed N.Clinical validation is required before utilisation for emergency care of haemorrhagic shock.

Tree Pollen Sensitization and Cross-Reaction of Children with Allergic Rhinitis or Asthma / 고신대학교의과대학학술지

OBJECTIVES: Tree pollen causes allergic rhinitis and asthma. We investigated children who diagnosed as rhinitis or asthma, living in Busan, for tree allergen sensitization, component allergen, oral allergy syndrome, and the relationship between pollen counts and allergen sensitization.METHODS: Pollen were collected in Busan, from January 1 to December 31, 2017, using a Rotorod sampler and enumerated using a microscope. We conducted a study of children with rhinitis or asthma at Busan St. Mary's Hospital in 2017, administered an ISAAC questionnaire, and an oral allergy syndrome survey. Serum specific Ig E tests were performed.RESULTS: Among the 57 patients, the mean age was 9.3 years. The pollen counts in decreasing order were as follows: pine, alder, oak, juniper, beech, ginkgo, and birch. For sensitization, birch and alder 35.1%, Japanese cedar 19.3%, juniper 17.5%, pine 10.5%, and Japanese cypress 8.2%. The component Ig E was tested in 27 patients. Bet v 1 had a high correlation with birch, alder, and peach. Bet v 2 showed a statistically significant correlation with all tree pollen except cypress. Bet v 4 did not have any apparent correlation. Bet v 6 had the same pattern as Bet v 2, but correlation coefficient was higher than that of Bet v 2. Oral allergy syndrome was noted in 7 patients, including peach, peanut, apple, tomato, kiwi, and sesame.CONCLUSIONS: Alder and juniper are clinically important tree pollens in Busan. These pollens cause sensitization to birch and Japanese cedar by cross-reaction.

Developing a Basic Scale for Workers' Psychological Burden from the Perspective of Occupational Safety and Health

BACKGROUND: Organizations are pursing complex and diverse aims to generate higher profits. Many workers experience high work intensity such as workload and work pressure in this organizational environment. Especially, psychological burden is a commonly used term in workplace of Republic of Korea. This study focused on defining the psychological burden from the perspective of occupational safety and health and tried to develop a scale for psychological burden. METHODS: The 48 preliminary questionnaire items for psychological burden were prepared by a focus group interview with 16 workers through the Copenhagen Psychosocial Questionnaire II and Mindful Awareness Attention Scale. The preliminary items were surveyed with 572 workers, and exploratory factor analysis, confirmatory factor analysis, and correlation analysis were conducted for a new scale. RESULTS: As a result of the exploratory factor analysis, five factors were extracted: organizational activity, human error, safety and health workload, work attitude, and negative self-management. These factors had significant correlations and reliability, and the stability of the model for validity was confirmed using confirmatory factor analysis. CONCLUSION: The developed scale for psychological burden can measure workers' psychological burden in relation to safety and health. Despite some limitations, this study has applicability in the workplace, given the relatively small-sized questionnaire.

Endoscopic drainage in patients with inoperable hilar cholangiocarcinoma

Hilar cholangiocarcinoma has an extremely poor prognosis and is usually diagnosed at an advanced stage. Palliative management plays an important role in the treatment of patients with inoperable hilar cholangiocarcinoma. Surgical, percutaneous, and endoscopic biliary drainage are three modalities available to resolve obstructive jaundice. Plastic stents were widely used in the past; however, self-expanding metal stents (SEMS) have become popular recently due to their long patency and reduced risk of side branch obstruction, and SEMS are now the accepted treatment of choice for hilar cholangiocarcinoma. Bilateral drainage provides more normal and physiological biliary flow through the biliary ductal system than that of unilateral drainage. Unilateral drainage was preferred until recently because of its technical simplicity. But, with advancements in technology, bilateral drainage now achieves a high success rate and is the preferred treatment modality in many centers. However, the choice of unilateral or bilateral drainage is still controversial, and more studies are needed. This review focuses on the endoscopic method and discusses stent materials and types of procedures for patients with a hilar cholangiocarcinoma.