雄黄的毒性研究

目的 研究雄黄的毒性特点,提出雄黄的相对安全用药剂量和用药时间建议,为雄黄的临床安全用药提供科学依据.方法 小鼠单次灌胃给药,测定LD50.采用SD大鼠随机分为对照组和雄黄5,10,20,80,160 mg· kg-1·d-1(相当于药典剂量高限的1/2,1,2,8,16倍)剂量组,各剂量组均每日灌胃给药1次,连续3个月,于给药后1,2,3个月和停药1个月,测定尿液定性、血常规以及血清生化指标,并观察肝、肾、心、脑等主要脏器的组织形态学变化,确定无明显不良作用水平( NOAEL).以世界卫生组织认为的人群内对化合物的敏感性差异倍数(10)乘以药理学上按照体表面积折算大鼠与人剂量的倍数(约为6)作为安全系数(60),结合NOAEL估计不同用药周期内的相对安全剂量.参照我国相关的技术指导原则规定的1个月动物长期毒性试验支持临床试验用药周期2周的方法,估计雄黄相对安全的用药时间.结果 在雄黄中As2S2质量分数为90%,可溶性砷为1.696 mg·g-1情况下,给小鼠单次灌胃给药的LD50为20.5 g·kg -1(等于摄入可溶性砷34.8 mg·kg-1),相当于人日用量约12812倍.而给大鼠反复灌胃给药时,雄黄超过一定剂量用药达到2个月或以上时,可造成肾脏和肝脏病理损害,其中肾脏显示更为敏感.大鼠灌胃雄黄1,2,3个月的无明显毒性剂量(NOAEL)分别为160,20,10 mg· kg-1·d-1(累积摄入可溶性砷8.14,2.04,1.53 mg·kg-1).估计临床使用雄黄的相对安全剂量范围为10～160mg(依用药时间不同).结论 反复使用雄黄时,建议在可溶性砷≤1.7mg·g-1的条件下,雄黄用药1～2周时,剂量不超过160 mg;用药2～4周时,剂量不超过20 mg;如果降低剂量至10 mg或以下,则在用药6周内相对安全.     

Registered nurses' efforts to ensure safety for home-dwelling older patients

Background

The international development of health care, an ageing population and rapid technical development mean that more care is being performed in patient homes. This care environment is often unpredictable and involves both formal and informal caregivers, making it potentially unsafe. There is sparse knowledge about how patient safety is protected in home health care in Sweden and how registered nurses work to prevent risks and promote safe care.

Aim

The aim of the study was to explore registered nurses' efforts to reduce perceived risks for home-dwelling older patients and ensure safe home health care.

Method

We used a qualitative design with individual interviews with 13 registered nurses working in municipalities in southeast Sweden. The narratives were analysed with inductive content analysis.

Findings

The findings showed that the registered nurses tried to secure a safe care environment and took an active role in care, striving to stay one step ahead of the patient. These three types of efforts are likely interdependent, suggesting they are all needed to reduce perceived risks for home-dwelling older patients and ensure patient safety in home health care.

Conclusions

It is a challenge for registered nurses to maintain patient safety when performing care in patient homes. Continuity of care is required and must be based not only on self-reliance among registered nurses but also on trusting relationships with patients, next of kin, colleagues and other personnel, as well as on the development of organisational conditions adapted to patient needs.     

Insomnia symptoms and risk of bloodstream infections: prospective data from the prospective population-based Nord-Trøndelag Health Study (HUNT), Norway

Previous research suggests decreased immune function and increased risk of infections in individuals with insomnia. We examined the effect of insomnia symptoms on risk of bloodstream infections (BSIs) and BSI-related mortality in a population-based prospective study. A total of 53,536 participants in the second Norwegian Nord-Trøndelag Health Study (HUNT2) (1995–97) were linked to prospective data on clinically relevant BSIs until 2011. In Cox regression, we estimated hazard ratios (HRs) with 95% confidence intervals (CIs) for a first-time BSI and for BSI-related mortality (BSI registered ≤30 days prior to death) associated with insomnia symptoms. Compared with participants who reported “no symptoms”, participants reporting having “difficulty initiating sleep” (DIS) often/almost every night had a HR for a first-time BSI of 1.14 (95% CI 0.96–1.34). Participants reporting “difficulties maintaining sleep” (DMS) often/almost every night had a HR of 1.19 (95% CI 1.01–1.40), whereas those having a feeling of “non-restorative sleep” once a week or more had a HR of 1.23 (95% CI 1.04–1.46). Participants frequently experiencing all three of the above symptoms had a HR of 1.39 (1.04–1.87), whilst those who had both DIS and DMS had a HR of 1.15 (0.93–1.41) and being troubled by insomnia symptoms to a degree that affected work performance was associated with a HR of 1.41 (95% CI 1.08–1.84). The HRs for BSI-related mortality suggest an increased risk with increasing insomnia symptoms, but the CIs are wide and inconclusive. We found that frequent insomnia symptoms and insomnia symptoms that affected work performance were associated with a weak positive increased risk of BSI.