Urinary tract injuries during obstetric intervention

A retrospective case record review of obstetric urinary tract injury in the Grampian region from 1976 to 1993 identified 16 cases of bladder injury (0.1 per 1000 deliveries, 1.4 per 1000 caesarean sections and four cases of ureteric injury (0.03 per 1000 deliveries, 0.27 per 1000 caesarean sections). Diagnosis of bladder injury was immediate, but of ureteric injury often delayed. Although the injury rates are lower than previously reported and previously reported risk factors not confirmed, this audit has resulted in guidelines for junior staff, compliance with which will be monitored, and every case of urinary tract injury will be reviewed.     

Reversal of sterilisation by the railroad technique

Objective To show that a simple, easily learned and relatively inexpensive method of reversal of sterilisation provides good results.
Design Retrospective observational study.
Setting An NHS Trust Hospital.
Sample Sixty-seven women aged 19 to 39 years who underwent reversal of sterilisation between January 1984 and December 1993.
Main outcome measures Pregnancy rate following reversal; rate of ectopic pregnancy.
Results Thirty-four women (51%) had intrauterine pregnancies after reversal of sterilisation; intrauterine pregnancy rate in women who had been sterilised with rings or clips was 64%. Five women (7.5%) had ectopic pregnancies.
Conclusion This technique provides results that compare favourably with those of microsurgery. It offers hope to couples who do not meet the restrictive criteria for microsurgery and in vitro fertilisation and should appeal to purchasing authorities.     

Neonatal mortality amongst Scottish preterm singleton births (1985–1994)

Objective To provide a valid estimate of singleton neonatal mortality based on birthweight and gestational age at delivery.
Design Record linkage of maternity data and neonatal mortality data.
Setting Scotland, UK.
Population All singleton preterm deliveries from 24 to 36 weeks inclusive between 1985 and 1994.
Main outcome measure Neonatal death.
Results There were 625,646 liveborn singleton deliveries over the study period, of which 33,912 were preterm (5.4%). The overall neonatal mortality in the preterm group was 41/1000 and the data have been presented by both gestational age and birthweight. The neonatal mortality rate fell with advancing gestation from 795/1000 live births at 24 weeks to 9/1000 live births at 36 weeks and was higher at the extremes of birthweight for a given gestational age. There was a significant increase in the proportion of babies delivered iatrogenically over the study period (χ test for trend   P < 0.001  ).
Conclusion This is the largest recent series to consider neonatal mortality using both birthweight and gestational age. These figures will be of use in obstetric management when elective preterm delivery is considered, and for providing prognostic guidance following preterm delivery.     

血液透析脑型失衡综合征发生机制的研究

目的 探讨血液透析脑型失衡综合征的发生机制。方法 采用急性肾功能衰竭的动物模型,观察血液透析后血浆渗透浓度迅速下降对脑水含量、颅内压、脑脊液生化和酸碱平衡的影响。结果 血液透析使血浆渗透浓度迅速下降,形成明显的脑/血渗透浓度梯度和尿素浓度梯度,使脑水含量明显增加,颅内压显著升高。透析后脑脊液pH下降、碳酸氢根(HCO_3~-)降低、Pco_2升高,与同期血浆相应值比较,差异有显著性意义(P<0.05)。结论 血液透析引起的血浆尿素氮快速下降可以导致脑水增加及颅压增高,其机制主要是由尿素的反向渗透效应引起。