Biomedical subjects
R C Pattinson
Publications and source records attributed to R C Pattinson.
Screening for anemia in pregnancy with copper sulfate densitometry.
OBJECTIVE: The copper sulfate method of screening for anemia was evaluated to determine its accuracy in antenatal patients. METHODS: In an antenatal clinic in a tertiary referral center, which also serves a local urban black community, 100 antenatal patients were prospectively tested for anemia by Coulter hemoglobin analysis in comparison with the copper sulfate test. The respective accuracy and costs of the tests were evaluated. RESULTS: Once initial technical difficulties had been overcome, the copper sulfate test proved accurate in detecting a hemoglobin level < 10 g% in pregnancy (sensitivity 94%, specificity 95%, positive predictive value 80%, negative predictive value 99%). The cost of the copper sulfate test is estimated to be less than 0.3% that of the Coulter test. CONCLUSION: The copper sulfate test is accurate and inexpensive, and can be recommended for screening for anemia in pregnancy.
The potential for preventing the delivery and perinatal mortality of low-birth-weight babies in a black urban population.
OBJECTIVE: To determine the potential for preventing the delivery and perinatal mortality of low-birth-weight (LBW) babies in a black urban population. DESIGN: Cross-sectional descriptive study. SETTING: All women delivering babies weighing less than 2,500 g at Kalafong Hospital in a 6-month period (December 1991-May 1992). MAIN OUTCOME MEASURES: The primary obstetric reason for delivery; whether the labour was of spontaneous onset or iatrogenic; whether labour was theoretically preventable using currently accepted practice; the number of patients in whom suppression of delivery was attempted in the theoretically preventable group; and the perinatal mortality rate of that group. RESULTS: There were 124 perinatal deaths (22.5%) in the 550 LBW babies delivered from 465 singleton pregnancies, 42 twin pregnancies and 1 triplet pregnancy. The primary obstetric reasons for delivery were spontaneous preterm labour (28%), hypertensive diseases (19%), premature rupture of membranes (18%), spontaneous labour in light-for-gestational-age babies (16%), unexplained intra-uterine deaths (8%), antepartum haemorrhage (8%) and other causes (3%). A medical decision to terminate the pregnancy before labour was made in 177 (34.8%) cases, the major reason being hypertensive diseases (84 mothers; 47.5%). In the remaining 331 mothers with spontaneous onset of labour, labour was theoretically preventable in 63 (19%) and prevention was only attempted in 12 (2.4% of the total mothers). The major reason for not attempting to suppress labour in the others was that the patients arrived too late at the hospital for intervention to take place. CONCLUSION: Hospital staff can do little to prevent the delivery of LBW babies in a black urban population.
Improving care for patients undergoing curettage for incomplete abortion.
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Induction of labour at term--misoprostol, efficacy, economics and ethics.
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Randomised clinical trial of medical evacuation and surgical curettage for incomplete miscarriage.
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Relationship between the fetal heart rate pattern and perinatal mortality in fetuses with absent end-diastolic velocities of the umbilical artery: a case-controlled study.
Fetal decompensation is usually diagnosed by the onset of late decelerations and decreased fetal heart rate (FHR) variability and is associated with fetal hypoxemia and acidemia and has a high perinatal mortality. Objective analysis of the FHR pattern can be performed using the Fischer score and a score of less than 6 correlates with fetal decompensation. Fetuses with absent end-diastolic velocities (AEDV) of the umbilical artery have severe placental disease and coupled with this a high perinatal mortality and morbidity. Importantly, AEDV is usually observed before the occurrence of fetal decompensation. In fetuses with AEDV, delivery before decompensation may improve the perinatal mortality and morbidity. To test this hypothesis, the perinatal outcome of fetuses with AEDV delivered before decompensation (Fischer score of 6 or more), were compared with similar fetuses delivered after decompensation (Fischer score of less than 6). All FHR pattern records of fetuses who had AEDV with a birthweight greater than 750 g and a gestational age of 28 weeks or more were evaluated using Fischer's score by a single observer unaware of the perinatal outcome. Fifty-seven fetuses qualified for the study and 17 of these babies subsequently died. The babies who died had significantly lower mean Fischer scores during the preceding 6 hours before delivery (5.9 +/- 1.8 SD) than the survivors (7.7 1.9; p < 0.05), but also had lower birthweights and gestational ages.(ABSTRACT TRUNCATED AT 250 WORDS)
Practical application of data obtained from a Perinatal Problem Identification Programme.
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The value of incorporating avoidable factors into perinatal audits.
OBJECTIVE: To assess whether incorporating a system of identifying, classifying and grading avoidable factors into a perinatal audit can be useful in identifying problem areas. DESIGN: Descriptive study. SETTING: Black urban population, Pretoria, South Africa. SUBJECTS: All perinatal deaths of infants weighing more than 1,000 g from urban areas served by Kalafong Hospital between August 1991 and July 1992. METHODS: All perinatal deaths were classified according to the primary obstetric cause of death and neonatal cause of death, and whether any avoidable factors were present which could have contributed to the death. RESULTS: The perinatal mortality rate was 26/1,000 deliveries. Avoidable factors occurred in 58% of perinatal deaths. Our problem areas which were immediately remedial were identified as labour management-related problems, administrative problems in obtaining syphilis results, and estimation of fetal weight. Other problem areas which need to be solved are patient education, early attendance at clinics, improved documentation and continuing education of medical personnel. CONCLUSION: The use of this classification of avoidable factors has enabled the detection of problem areas that can be improved immediately at very little cost.
Audit incorporating avoidability and appropriate intervention can significantly decrease perinatal mortality.
OBJECTIVE: To evaluate the role of the ICA (Identification, Cause, Avoidable factor) Solution method of perinatal audit in reducing perinatal mortality. DESIGN: Retrospective audit of 1,060 perinatal deaths between 1 January 1991 and 31 December 1992. SETTING: Livingstone Hospital Maternity Service. SUBJECTS: One thousand and sixty perinatal deaths, where the gestational age exceeded 28 weeks or, when gestational age was unknown, the birth weight was equal to or exceeded 1,000 g. MAIN OUTCOME MEASURES: All perinatal deaths were identified and classified by primary obstetric cause for perinatal loss. In the second year of the study avoidable factors were sought and, if found, graded and categorised. RESULTS: The major primary obstetric causes of perinatal loss identified and amenable to intervention were intrapartum trauma, intrapartum asphyxia and infection. In the second year of study potentially avoidable factors were sought and identified in almost 50% of perinatal deaths. Appropriate intervention lowered the perinatal mortality rate by 23% (P < 0.05; odds ratio 0.76; 95% confidence interval 0.67-0.86). CONCLUSION: The ICA Solution method of perinatal audit identified problems in overall obstetric care, facilitating a significant fall in perinatal mortality.
Ampicillin and metronidazole treatment in preterm labour: a multicentre, randomised controlled trial.
OBJECTIVE: To ascertain whether adjuvant ampicillin and metronidazole given to women in preterm labour with intact membranes would prolong pregnancy and decrease the perinatal mortality and morbidity. DESIGN: A multicentre, prospective, randomised controlled trial. SETTING: Three perinatal centres serving an indigent population. SUBJECTS: Eighty-one women in active preterm labour with otherwise uncomplicated singleton pregnancies between 26 and 34 weeks gestation or an ultrasound fetal weight estimate of 800 g to 1500 g. INTERVENTIONS: The study group received ampicillin and metronidazole for five days. The control group received no antibiotics. In all women contractions were suppressed with hexoprenaline and indomethacin for 24 h, and betamethasone was given for fetal lung maturity. MAIN OUTCOME MEASURES: Days gained and perinatal mortality and morbidity. RESULTS: The study (n = 43) and control groups (n = 38) were comparable at entry. In those receiving ampicillin and metronidazole the pregnancy was significantly prolonged (median 15 days versus 2.5 days, P = 0.04) with significantly more women still pregnant after seven days (63% versus 37%, P = 0.03, OR 0.34 95% CI 0.13-0.94). Significantly more infants in the control group developed necrotising enterocolitis than in the study group (5 versus 0, P = 0.02). CONCLUSION: Adjuvant ampicillin and metronidazole in the management of women in preterm labour with intact membranes significantly prolonged the pregnancy and decreased neonatal morbidity.
The role of Doppler velocimetry in the management of high risk pregnancies.
OBJECTIVE: To determine whether knowledge of the result of Doppler velocimetry of the umbilical artery is beneficial to the management of a high risk pregnancy. DESIGN: Randomised controlled trial. The trial was of the management type, designed to assess benefit accruing from additional information supplied by Doppler velocimetry. SETTING: Tygerberg Hospital, Cape Town, South Africa. The hospital serves a population from the lower socio-economic groups. SUBJECTS: Women with pregnancies 28 or more weeks gestation with hypertensive diseases and/or suspected small for gestational age fetuses were referred for Doppler velocimetry. From this population, three subsets were formed: 1. those with fetuses with absent end-diastolic velocities (20 fetuses); 2. those with hypertension but with fetuses with end-diastolic velocities (89 fetuses); and 3. those with fetuses suspected of being small for gestational age but with end-diastolic velocities (104 fetuses). INTERVENTIONS: Doppler velocimetry on all subjects. The study group consisted of 10 cases with absent end-diastolic velocities, 47 cases with hypertensive diseases with end-diastolic velocities and 51 cases with suspected small for gestational age fetuses but with end-diastolic velocities in which the result was revealed to the clinician. The control group consisted of 10, 42 and 53 cases, respectively, in which the Doppler results were not revealed. All other routine investigations (sonar and antenatal fetal heart rate monitoring) were available to the clinicians. Standard management protocols were followed in all groups. MAIN OUTCOME MEASURES: Perinatal mortality and morbidity, antenatal hospitalisation, maternal intervention, admission to the neonatal intensive care unit and hospitalisation until discharge from the neonatal wards. RESULTS: In the study and control groups the gestational age at entry to the study, maternal age, parity and various complications were not significantly different. In the subset with absent end-diastolic velocities, there was one neonatal death in the study group, but in the control group there were six deaths, five intrauterine and one perinatally related infant death (P = 0.029). Because of this significant finding, the study was stopped. There were no differences in outcome in the subset where there was hypertensive disease with end-diastolic velocities between the study and control groups. In the subset in which small for gestational age fetuses were suspected, but in which end-diastolic velocities were present, the women in the study group had significantly fewer days in hospital before delivery (P < 0.001) and tended to have fewer maternal interventions (study group = 27%, control group = 43%; P = 0.07; odds ratio (OR) 0.49, 95% confidence limits (CL) 0.2 and 1.25) and caesarean sections (study group = 13%, control group = 27%; P = 0.08; OR 0.43, 95% CL 0.14 and 1.32). The infants of the study group in this subset also spent significantly less time in the neonatal wards (P = 0.029).
Is ward evacuation for uncomplicated incomplete abortion under systemic analgesia safe and effective? A randomised clinical trial.
OBJECTIVE: To compare evacuation under systemic analgesia (fentanyl and midazolam) in a treatment room (ward group) with evacuation under general anaesthesia in theatre. DESIGN: A prospective randomised clinical trial. SETTING: A tertiary medical centre serving a black urban population. SUBJECTS: One hundred and forty-two patients with uncomplicated incomplete abortions. INTERVENTION: Randomisation into two groups, those for evacuation under systemic analgesia and those for evacuation under general anaesthesia. MAIN OUTCOME MEASURES: Both groups were compared in terms of safety, efficacy, acceptability, blood consumption and time delay between admission and evacuation. RESULTS: Significantly less blood was used in the ward group (37 units for 13 patients) than in the theatre group (65 units for 24 patients) (P < 0.03). Significantly less time was taken between admission and evacuation in the ward group (median 7 hours 15 minutes) than in the theatre group (median 12 hours 38 minutes) (P < 0.0003). Evacuation under fentanyl and midazolam was safe, effective and acceptable for the majority of patients compared with evacuation under general anaesthesia. CONCLUSION: Patients with uncomplicated incomplete abortions (uterine size equivalent to a pregnancy of 14 weeks' duration or less) can undergo evacuation safely and effectively under fentanyl and midazolam and have a significantly smaller chance of requiring a blood transfusion.
Unselected referrals from peripheral provincial hospitals.
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The relationship between absent end-diastolic velocities of the umbilical artery and perinatal mortality and morbidity.
To determine the perinatal mortality and neonatal morbidity of fetuses with absent end-diastolic velocities (AEDV) of the umbilical artery, the outcome of 120 fetuses, with a gestational age of 24 weeks or more and a birth weight of 500 g or more, with AEDV at the last Doppler examination, were analyzed. The study population came from 348 women who had pregnancies at high risk of placental insufficiency and had had Doppler velocimetry examinations. In all the women, the Doppler velocimetry result was withheld from the clinician managing the woman. Of the fetuses with AEDV, 57 (52%) died and only 26 (22%) babies had minimal or no neonatal morbidity. All 24 fetuses with AEDVs delivering before 28 weeks gestation and having a birth weight less than 750 g died. When compared with fetuses from the study population with end-diastolic velocities present, the gestational age and birth weight at delivery was significantly lower, and the perinatal mortality, neonatal morbidity and number of light for gestational age (LGA) babies was significantly higher in the AEDV group. The LGA babies from both groups were compared by gestational age category and the LGA babies with AEDV still had a significantly higher perinatal mortality. There was no difference in the pattern of neonatal complications or causes of neonatal deaths between the two groups.
Obstetric and neonatal outcome in fetuses with absent end-diastolic velocities of the umbilical artery: a case-controlled study.
Absence of end-diastolic velocities (AEDV) is the most severe waveform abnormality detected by Doppler ultrasound examination of the umbilical artery. It is associated with fetal hypoxemia and acidemia. If AEDV predisposed to more neonatal complications, then it might be an indication for earlier delivery. This was investigated in 21 preterm fetuses with AEDV who were matched for gestational age at delivery with 21 with end-diastolic velocities. All fetuses were delivered electively before 36 weeks' gestation of mothers who were hypertensive. The fetal heart rate (FHR) variability, birthweight, and umbilical arterial blood pH were significantly lower in the AEDV group. However, the neonatal outcomes were similar except for less severe hyaline membrane disease and lower initial platelet counts in the AEDV group. At present, fetuses with umbilical arterial AEDV need not be delivered earlier than indicated by the FHR pattern, nor should neonatal management be altered on the basis of antenatal AEDV.
The use of Doppler velocimetry of the umbilical artery before 24 weeks' gestation to screen for high-risk pregnancies.
OBJECTIVE: To describe the prevalence and natural history of absent end-diastolic velocities (AEDV) in the umbilical artery of the fetus between 16 and 24 weeks' gestation, and to evaluate its role as a screening test. DESIGN: Population-based descriptive study. SETTING: Tygerberg Hospital, Tygerberg, South Africa. The hospital serves a population from the lower socio-economic bracket. SUBJECTS: Doppler velocimetry was performed at routine ultrasound examinations for confirmation of gestational age in 496 women. MAIN OUTCOME MEASURES: The occurrence of perinatal death, small-for-gestational-age (SGA) babies and proteinuric hypertension. RESULTS: Forty-four (8.9%) patients had AEDVs at the first examination, but AEDV persisted in only 1. In this case, severe proteinuric hypertension developed unexpectedly at 29 weeks' gestation and the fetus needed delivery because of persistent late decelerations of the fetal heart rate pattern. There was a significant association between the group with AEDV at first examination and the development of proteinuric hypertension (P < 0.05), but no association with SGA babies. The association with proteinuric hypertension was too weak to be of clinical use. CONCLUSION: Doppler velocimetry of the umbilical artery, performed along with routine ultrasound examination to confirm gestational age, is not of use as a screening test for identifying high-risk pregnancies.