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Biomedical subjects

R F Harrison

Publications and source records attributed to R F Harrison.

At least 109 records · Page 6Linked to original sources

Pain relief in labour using transcutaneous electrical nerve stimulation (TENS). A TENS/TENS placebo controlled study in two parity groups.

The analgesic effects of transcutaneous electrical nerve stimulation (TENS) in labour and effects on outcome were investigated in a double-blind TENS/TENS placebo controlled trial in 100 primigravidae and 50 women in their third labour. There were no differences between the TENS and the TENS placebo users in terms of pain concept or relief, and only 12 and 13% of primigravidae and 48 and 39% of the para 2 women completed labour without requiring other analgesia in their respective groups. The primigravidae who used either TENS or TENS placebo alone had shorter labours than those who required further analgesia. Although the outcome of labour for mother and infant were similar in the two groups, there was a higher operative delivery rate in women who also had epidural analgesia. There were highly significant differences between the TENS and the TENS placebo users in terms of favourable and unfavourable comments by the mothers and the midwives at 1 and 24 h after delivery. The evident consumer satisfaction for TENS suggests TENS has a part to play in analgesia in labour but the equivocal findings in terms of factors associated with pain relief points to the need for apparatus more specifically designed to cope with the special characteristics of the pain of labour.

Clinical Trials as Topic↗

Retinal hemorrhage thresholds for Q-switched neodymium-Yag laser exposures.

Thresholds for retinal vitreal and contained hemorrhages were determined for 1064 nm laser light at 30-nsec and 4-nsec pulsewidths. Rhesus monkeys received graded exposures from a neodymium-yag laser onto either the macular or extramacular region of the retina. Contained hemorrhages appeared as concentric ring structures with white punctate centers. The vitreal hemorrhage was characterized by the presence of choroidal blood in the vitreal chamber at the exposure site. The 30-nsec contained hemorrhage threshold (ED50) was 1.7 mJ on the macula and 2.1 mJ for an extramacular exposure. The 30-nsec vitreal hemorrhage macular threshold was 2.3 mJ, and the extramacular threshold was 6.6 mJ. The threshold for the 4-nsec pulsewidths to produce a hemorrhage (vitreal or contained) on the retina (macula or extramacular) was 340 microJ.

Animals↗

Treatment of habitual abortion with human chorionic gonadotropin: results of open and placebo-controlled studies.

Human chorionic gonadotropin was administered intramuscularly in an open study of 32 women whose last three pregnancies had ended in spontaneous abortion. An initial dosage of 10 000 iu on earliest diagnosis of pregnancy was followed up by 5000 IU twice weekly up to wk 12, then once weekly up to wk 16. Only 2 of the 32 patients aborted (6.2%). Using the same regime a further 20 habitual aborters were randomly allocated double-blind to either hCG or placebo. All 10 women on active therapy continued (100%) compared with only 3 on placebo (30%) (P less than 0.01). These results suggest that hCG should be considered as treatment in women with habitual abortion where other specific causes have been ruled out and a potentially treatable hormonal imbalance surmised.

Abortion, Habitual↗

Ocular effects of pulsed Nd laser radiation: variation of threshold with pulsewidth.

This study of retinal damage thresholds in the rhesus monkey eye investigated the effects of Nd:YAG laser radiation at four pulsewidths; 4, 30, and 200 ns, and 10 microseconds. The thresholds for induction of minimal ophthalmoscopically visible lesions for the four pulsewidths were 158, 326, 170, and 425 microJ, respectively, incident at the eye in single-pulse exposures. The data are interpreted to imply a flat trend of threshold with pulsewidth over the range of pulsewidths examined, in agreement with maximum permissible exposures quoted in existing laser safety standards. This finding is in contrast with the hypothesis of an anomalous trend of increasing threshold with decreasing pulsewidth which was suggested for the nanosec-microsec pulsewidth range based on the sparse data base previously available.

Animals↗

Is routine episiotomy necessary?

One hundred and eighty one primigravid women delivering vaginally in July and August 1982 in the Rotunda Hospital, Dublin, were randomly allocated to one of two groups. Patients in one group were to undergo episiotomy. Those in the other group were not to undergo episiotomy unless it was considered to be essential. The outcome was compared with that of the clinical practice over the previous six months at the hospital. Of the 92 patients allocated not to undergo episiotomy, seven (8%) had one done for medical reasons compared with 507 (89%) in the previous six months. First degree tears occurred in 23 (25%) and second degree tears in 43 (47%). Nineteen (21%), however, retained an intact perineum compared with only 35 (6%) of the women who had delivered in the preceding six months. Assessments of perineal pain, bruising, swelling, and healing and records of ingestion of analgesics were made for the first four days after delivery, and again at a check up six weeks after delivery, in patients who had had spontaneous vertex deliveries. Forty patients who underwent episiotomy and 37 who sustained a second degree tear formed two comparable groups. There was no difference in outcome between them. Data were also evaluated for 19 women who retained an intact perineum, 22 who sustained a first degree tear, and 11 who underwent episiotomy and epidural anaesthesia; all 52 of these women had spontaneous vertex deliveries. Despite severe soft tissue injury in two patients those who fared best were those who retained an intact perineum. First degree tears were associated with symptoms similar to those associated with second degree tears. Those who fared worst were women who underwent episiotomy after epidural anaesthesia. The value of routine episiotomy in primigravid patients is questioned, but the final decision can be made only by the accoucheur at the time of imminent delivery.

Adolescent↗

Corneal damage induced by pulsed CO2 laser radiation.

Corneal damage thresholds were determined in Dutch Belted rabbits following CO2 laser radiation with pulse widths of 1.7, 25 and 250 ns. The threshold values for corneal clouding found for the 3 cases were 0.33, 0.54 and 0.18 J/cm2, respectively. These results are in accord with expectations based on a thermal-damage mechanism, with no evidence of acoustic shock or other mechanisms contributing to the observed damage for the exposure parameters used in this study. The data support the suggested maximum permissible exposure levels for short-pulse far-infrared laser radiation as quoted in current laser safety standards.

Animals↗

Psychosomatic aspects in idiopathic infertility: effects of treatment with autogenic training.

It has long been recognised that there is a relationship between emotional stress and some forms of infertility. We have endeavoured to estimate "stress' levels before and after Autogenic Training in 15 couples with infertility of at least two years' duration. Potential stress markers were: plasma prolactin, total urinary free cortisol and catecholamines, and four psychological tests: Spielberger State-Trait anxiety scale, Taylor Manifest Anxiety Scale, the Cattell 16 personality factor questionnaire, and the Eysenck Personality Questionnaire. A control group of ten normal couples was included for comparison. The biochemical finding of higher mean prolactin levels in the female patients vs their controls was of particular interest. The significant reduction of the prolactin level, in parallel with decreased anxiety scores following treatment, supports the hypothesis that the elevated prolactin levels in these patients are indeed linked with emotional stress.

Adult↗

Ethamsylate in the treatment of climacteric flushing.

Ethamsylate, a non-hormonal agent acting at the capillary level, was compared with a placebo in a double-blind trial of 12 wk duration in 20 post-menopausal patients with hot flushes. Both ethamsylate and placebo patients showed fluctuations in the frequency of flushes during the trial, but there was a significant downward trend in the ethamsylate group. Capillary strength was measured but was not found to be low or to alter during the trial except in 1 patient in the placebo group. No side-effects attributable to trial medication were reported. Other symptoms recorded during the trial were probably climacteric and occurred more frequently during placebo treatment than during treatment with ethamsylate.

Adult↗

The diagnostic and therapeutic potential of the postcoital test.

An analysis was made of postcoital tests carried out on 423 couples attending the Rotunda and St. James Hospitals in Dublin. Initially 66.6% of tests were abnormal, but 21.3% of these were invalid because of the presence of seminal or cervical abnormalities, leaving 57.7% of couples with initially valid negative tests. Retesting showed 30.3% of couples to have persistently negative tests, 24.5% of whom achieved pregnancy. Three per cent of abnormalities were immunologic in origin. The most common cause why a subsequently positive test was initially negative was failure to observe correct clinical procedures, but unadmitted psychosexual problems were present in 17.6% of cases. Of the best postcoital tests, 78.5% correlated well with semen analyses and 90.9% with basal body temperature charts. In total, 6.2% of all pregnancies achieved in the clinics followed postcoital testing.

Cervix Mucus↗