D. Cooper

Low molecular weight versus standard heparin for prevention of venous thromboembolism after major abdominal surgery

Abstract Low-molecular-weight heparin (LMWH) is effective in the prevention of postoperative venous thromboembolism but does it have the safety advantages over standard heparin (SH) that have been claimed? In a multicentre randomised trial in 3809 patients undergoing major abdominal surgery (1894 LMWH, 1915 SH) heparin was given preoperatively and continued for at least 5 postoperative days. Patients were assessed in the postoperative period and were followed up for at least 4 weeks, the emphasis being on safety. Major bleeding events occurred in 69 (3·6%) patients in the LMWH group and 91 (4·8%) patients in the SH group (relative risk 0·77, 95% confidence interval 0·56-1·04; p=0·10). 93 indices of major bleeding were observed in the 69 LMWH patients and 141 in the SH patients. (p=0·058). Severe bleeding was less frequent in the LMWH group (1 0% vs 1·9%; p=0·02), as was wound haematoma (1·4% vs 2·7%; p=0·007). Bleeding episodes with LMWH were less likely to lead to further surgery to evacuate a haematoma or to control bleeding, and injection site bruising was also less common in the LMWH group. No significant differences were found in the efficacy of the two agents. Perioperative death rates were 3·3% in the LMWH group and 2·5% in the SH group; pulmonary emboli were detected in 0·7% and 0·7%; and deep-vein thrombosis was diagnosed in 0·6% of patients in each group. Follow-up was done on 91% of 3699 evaluable patients. There were 19 further deaths (10 LMWH, 9 SH group) and 25 patients with thromboembolic complications (15 and 10). Of the 3 patients with fatal pulmonary emboli during follow-up 2 had received LMWH and 1 SH. The two drugs were of similar efficacy. The primary end point, the frequency of major bleeding, showed a 23% reduction in the LMWH group, but this difference was not significant. The secondary safety end points revealed that LMWH was significantly better than SH. Fatal pulmonary embolism occurs rarely (0·09%) following discharge from hospital so the cost benefit ratio would not justify prolonged prophylaxis in this setting.

Doppler investigation of uteroplacental blood flow resistance in the second trimester: a screening study for pre‐eclampsia and intrauterine growth retardation

Objective— To assess the screening properties of a mid‐trimester uteroplacental Doppler scan in a normal unselected population.

Sex hormones and skin collagen content in postmenopausal women.

Skin biopsy specimens were taken from 29 postmenopausal women who had not been given hormone replacement therapy and from 26 women who had been treated with oestrogen and testosterone implants for two to 10 years. The mean hydroxyproline content and therefore the mean collagen content in the skin was found to be 48% greater in the treated than the untreated women, who were matched for age. This difference was significant (p less than 0.01). The implication of this finding is that oestrogen or testosterone, or both, prevents the decrease in skin collagen content that occurs with aging and protects skin in the same way as it protects bone in postmenopausal women.

The treatment of detrusor instability in postmenopausal women with oxybutynin chloride: a double blind placebo controlled study

Summary. Idiopathic detrusor instability is a common cause of incontinence in the elderly for which anticholinergic agents arc regularly prescribed. Oxybutynin chloride combines anticholinergic action with direct muscle relaxant properties. We performed a double blind placebo controlled fixed dose cross over study of oxybutynin chloride in postmenopausal women suffering from detrusor instability. We found oxybutynin chloride significantly more effective than placebo at reducing the symptoms of urgency and urge incontinence and more effective at reducing the height of the highest unstable detrusor contraction. This was at the expense of an increased residual urine and considerable side effects.

Correlation of urethral physiology and skin collagen in postmenopausal women

Summary. Connective tissue collagen is thought to contribute to the generation of urethral pressure. It has been previously shown that skin collagen and urethral pressure are oestrogen dependent. This study demonstrates a correlation between urethral pressure measurements and skin collagen content. It is suggested that the beneficial effect of oestrogens on urethral function may be mediated by collagen.

Subcutaneous hormone implants for the control of climacteric symptoms. A prospective study.

55 postmenopausal women on established hormone replacement therapy were treated with either oestradiol and testosterone implants or placebo at the time of return of climacteric symptoms. Their response to therapy was assessed prospectively. The statistically highly significant levels of symptom relief that followed an oestradiol and testosterone implant were contrasted sharply with the lack of any significant relief with placebo. Despite the success of oestradiol and testosterone implants in relieving symptoms of the climacteric, symptoms returned once the treatment was stopped. Evidence is presented that it is the fall in hormone levels rather than the level itself that provokes the return of climacteric symptoms.

Internal urinary sphincter in maintenance of female continence.

The integrity of the bladder neck was assessed in 98 continent women. Radiological and physiological evidence showed that half of these women had an incompetent bladder neck, but they were still continent. These data devalue the urodynamic finding of an incompetent bladder neck as an indication for surgery for incontinence and question the physiological importance of the internal sphincter.

NORMAL PATTERNS OF FETAL ACTIVITY IN THE THIRD TRIMESTER

The incidence and frequency of fetal respiratory movements (FRM) and fetal trunk movements (FTM) were measured in 21 normal pregnancies between 28 and 39 weeks gestation. Fetal activity was assessed with a real‐time ultrasound scanner and all observed movements were punched directly onto computer tape. Recordings were made for one hour in three over a 24 hour period, providing a total of 168 hours for analysis. The overall mean percentage incidence of FRM was 31 per cent at a mean breathing rate of 43 breaths/minute. The mean percentage incidence of FRM during the day (0800–1759 hours) was 37 per cent. The overall mean percentage incidence of FTM was 18 per cent with a mean of 29 moves per 30 minute observation period. The mean percentage incidence of FTM during the day (0800–1759 hours) was 16 per cent. There was a well‐defined circadian variation in fetal activity with FRM peaking between 1900 and 2200 hours, and FTM between 2200 and 0100 hours. There was considerable variation in the amount of FRM and FTM recorded from hour to hour. Total fetal activity rarely fell below 10 per cent in any one recording period and this measurement may be a more useful clinical test of fetal well‐being than FRM or FTM alone.

Predictive value of cervimetric labour patterns in primigravidae

Summary. From a study of 2000 consecutive labours the outcome of the 684 primigravid patients admitted in spontaneous labour has been examined according to their cervimetric progress during the first stage of labour. A partogram and labour stencil were used to identify dysfunctional labour which was treated with a standard protocol of augmentation by oxytocin. This policy achieved labours with a mean‘observed first stage’ of 6.3 h and a caesarean section rate of 8.7%. There was one stillbirth due to multiple congenital abnormalities and no increase in perinatal morbidity. Our data show that the type of first stage cervimetric pattern is helpful in predicting the outcome of labour. A normal cervimetric pattern resulted in a vaginal delivery rate of 98.4%; primary dysfunctional labour, which could be improved by oxytocin, had a 93.8% incidence of vaginal delivery, but if there was no improvement in the rate of cervical dilatation when this was administered the vaginal delivery rate was only 22.7%. A prolonged latent phase was associated with a caesarean section rate of 16.7% and the incidence of neonatal intubation was nearly as high as that found in uncorrected primary dysfunctional labour. The neonatal asphyxia in secondary arrest was minimal with an overall caesarean section rate of 28.4%; there was no increased incidence of neonatal morbidity with this cervimetric type.

Uteroplacental Doppler flow velocity waveforms in the second trimester. A complex circulation

Summary. Continuous wave Doppler ultrasound was used to examine the Uteroplacental circulation of an unselected group of 993 women between 16 and 24 weeks gestation. Reference ranges for resistance index (RI) were determined and throughout this gestation range there was a significant fall in RI with increasing gestation. The RI was lower from placental than non‐placental sites and from distal ‘arcuate’ than proximal ‘uterine’ sites. There is a need to define fixed standardized sites for sampling and for normal ranges to account for variables such as placental site.