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Biomedical subjects

S Chua

Publications and source records attributed to S Chua.

At least 37 records · Page 2Linked to original sources
PubMed1998

Arterial embolization for bleeding following hysterectomy for intractable postpartum hemorrhage.

Angiographic embolization is a well documented technique that has been utilized for controlling pelvic hemorrhage. A case is described of a 41-year-old para 3 woman with intractable bleeding following a cesarean hysterectomy for postpartum hemorrhage due to uterine atony and coagulopathy. On angiogram, no bleeding was seen from the uterine vessels. An injection of dye above the origin of the gonadal vessels showed persistent hemorrhage from the left ovarian artery. This report illustrates the importance of intensive resuscitation and supportive measures, and the value of angiographic embolization after failed surgery. It also emphasizes the need to locate the exact bleeding vessel on angiography for embolization to be successful.

Adult↗
PubMed1998

Lactate and acid-base balance at delivery in relation to cardiotocography and T/QRS ratios in the second stage of labour.

OBJECTIVE: To compare foetal electrocardiogram (T/QRS ratio) and cardiotocography (CTG) during the second stage of labour with lactate and acid-base balance in cord artery blood at delivery. DESIGN: Forty-six parturients delivered at the National University of Singapore were monitored during the second stage of labour with T/QRS ratios and CTG. At delivery blood from a segment of clamped cord was sampled for lactate and acid-base balance analyses. The Spearman Rank correlation, the Mann Whitney U-test and the Kruskal Wallis ANOVA were used when appropriate. RESULTS: Maternal pushing time was significantly correlated to lactate (R = 0.51; P = 0.0003), pH (R = -0.38; P = 0.009) and base deficit (R = 0.33; P = 0.026), but not to T/QRS ratio (R = 0.002; P = 0.99). No significant correlation between lactate and T/QRS ratios (R = 0.06; P = 0.70) or type of CTG pattern was found (P = 0.10), though there were significant differences in pH (P = 0.029) and T/QRS ratios (P = 0.037) between groups with different FHR abnormalities. CONCLUSION: Lactate increases progressively with maternal pushing time. No significant correlation was found between lactate and the T/QRS ratio. Lack of correlation is likely to be due to poor sensitivity of foetal ECG at this level of foetal stress, though the influence from transplacentally transferred maternal lactate cannot be excluded.

Acid-Base Equilibrium↗
PubMed1998

The reliability of catheter-tip transducers for the measurement of intrauterine pressure in the third stage of labour.

In order to assess the reliability of intrauterine pressure measurements in the third stage of labour, catheter-tip transducers were used in 20 women randomly allocated into two groups of 10. In each case in the first group two catheters were tied together and introduced transcervically into the uterine cavity after delivery of the placenta. In each case in the second group two catheters were inserted independently into the same uterine cavity. The active and cumulative active pressures recorded from the pairs of catheters within each uterine cavity were compared. Comparison of individual active pressure readings from separate transducers revealed good agreement whether the catheters were tied together or were separate. Cumulative active pressure was very similar when assessed by each catheter in the same uterus. Intrauterine catheter-tip transducers can be used reliably to measure uterine activity in the third stage of labour although there may be minor contraction by contraction differences in recordings of individual active pressures.

Catheterization↗
PubMed1998

Evaluation of a new portable system for cord lactate determination.

To evaluate a new reflectance photometer (Accusport) for blood lactate determination, a prospective non-interventional study was performed on blood obtained from the umbilical cord artery immediately after delivery of the baby in 109 consecutive women. For each sample, the results of cord arterial blood lactate values measured with the reflectance photometer were compared with those obtained using a reference method in the laboratory. The values obtained using Accusport were comparable in accuracy with those obtained using a laboratory reference method (Ektachem 9501RC). The instrument provides a simple and reliable method for determining cord arterial blood lactate levels in a small blood sample.

Blood Chemical Analysis↗
PubMed1998

Validation of a laboratory method of measuring postpartum blood loss.

Laboratory methods give more accurate measurement of blood loss in the postpartum period than visual estimation. In order to evaluate a laboratory method used to quantify blood loss postpartum, blood lost at gynecological operations was collected in a measuring bottle. The measured amount of blood (50-1,000 ml) was then poured onto absorbent paper towels and sanitary pads, in order to mimic conditions when measuring blood loss in clinical trials in the postpartum period. The amount of blood absorbed onto the absorbent paper and sanitary pads was measured by a rapid method of automatic extraction and photometric measurement of alkaline hematin. The study shows that the method provides a reliable and accurate means of measuring blood loss. The error in each case was less than 10% with an intraclass correlation coefficient of almost 1.

Analysis of Variance↗
PubMed1998

Correlation of change in uterine activity to blood loss in the third stage of labour.

In 47 women, the change in the uterine activity after the administration of a uterotonic agent was correlated with the amount of blood loss during the same period of time. Uterine activity was measured by a Gaeltec catheter-tipped pressure transducer inserted transcervically within 5 min of delivery of the placenta. A uterotonic agent (either intravenous syntocinon, intramuscular syntometrine or oral misoprostol) was given after the insertion of the intrauterine pressure catheter and pressure recorded for another 90 min. Blood loss over the same 2-hour period was collected with absorbent paper which was then assessed by colorimetric measurement of the haemoglobin content in the sample. Our results show that the change in uterine activity is associated with the total blood loss. However, there is a poor linear correlation between the two variables probably because of the biological variation in myometrial activity and differences in coagulation mechanisms in normal women.

Blood Coagulation↗
PubMed1998

Quality assessment of two lactate test strip methods suitable for obstetric use.

Accuracy of lactate determinations in cord blood was tested for one reflectometric (Accusport) and one amperometric (Lactate Pro) microvolume test strip lactate meter. Both meters, using a whole blood sample, measure lower levels of lactate than a reflectometric device considered as a reference method, which analyses lactate in plasma. Readings were unaffected irrespective of lactate concentrations for the Lactate Pro, whilst the Accusport overestimated low lactate concentrations and underestimated high values. Both lactate meters underestimated lactate concentrations at high hematocrits, as compared with the reference method. The Lactate Pro has a fixed sample volume of 5 microliters while the Accusport uses random blood drop as sample volume. However, in analyses with less than 20 microliters sample volume considerable underestimation was found with the Accusport. Coefficient of variation was 3.8-8.9% for the Accusport and 3.1-4.0% for the Lactate Pro within lactate concentrations between 2.1 and 5.3 mmol/l. The amperometric device, the Lactate Pro, performed best in these tests dealing with fetal blood lactate concentrations. The new technique can be a useful tool in perinatal research as well as in obstetric practice.

False Negative Reactions↗
PubMed1998

Mycotic aneurysm leading to iliac arteriovenous fistula diagnosed by vascular duplex color scan.

Arteriovenous fistula between common iliac vessels is uncommon. Most of the reported cases are secondary to lumbar disc surgery. Mycotic aneurysm of iliac vessels caused by bacterial infection is even rarer. We describe the case of a 63 year old man with dyspnea, abdominal pain, bipedal edema, chills and fever. He had a right common iliac AVF as a result of a ruptured salmonella mycotic aneurysm, and the diagnosis was made by vascular duplex color scan.

Aneurysm, Infected↗
PubMed1998

A case of accelerated development of proliferative diabetic retinopathy in a woman with type 2 diabetes mellitus after pregnancy.

Whilst it is recognised that diabetic retinopathy is a consequence of prolonged elevation of blood glucose levels, recent studies suggest rapid normalisation of blood sugar as a causal factor in accelerating its development. In this case report, a non-insulin dependent diabetic with poor blood glucose control but no retinopathy in early pregnancy had normalisation of glucose control by the third trimester. However, glucose control deteriorated rapidly postnatally, and she had a sudden blurring of vision three months after delivery of her baby, at which time severe proliferative diabetic retinopathy was diagnosed. The reason for the unusually rapid development of proliferative retinopathy was uncertain, but appeared to have a temporal association with the deterioration of her glycaemic control postnatal after a period of strict diabetes control in the perinatal period.

Adult↗
PubMed1998

Necrotising fasciitis originating from a vulval abscess--a case report.

This article reports a rare case of necrotising fasciitis starting out as a vulval abscess with rapid progression to a potentially lethal condition. Elderly people with medical conditions such as diabetes are especially prone to it. A high index of suspicion and an early surgical consult are essential in improving outcome in this condition. Once diagnosed, aggressive surgical debridement with antibiotic cover is crucial. This is followed up with meticulous nursing care of the large wound till it heals. The various diagnostic points and treatment modalities are also discussed.

Abdominal Muscles↗
PubMed1997

External cephalic version at term with tocolysis and vibroacoustic stimulation.

OBJECTIVE: This study compared the obstetric outcome in women who had external cephalic version (ECV) for breech presentation after 36 weeks gestation with those who did not, to see whether ECV reduces breech deliveries and cesarean section rates with reduced complications. METHOD: External cephalic version was attempted in 200 women (study group) with the use of tocolysis and vibroacoustic stimulation. The control group (ECV not attempted) comprised of 278 women with breech presentation after 36 weeks. RESULT: The cesarean section rate was 14.0% in the successful version group compared with 55.2% in the unsuccessful version group. The overall cesarean section rate in the study group was 32.5%. In the control group of 278, the fetus remained in the breech presentation in labor in 269 women with a cesarean section rate of 51.4% which was not different from the unsuccessful version group (55.2%). CONCLUSION: This study supports the randomized trials conducted earlier in that ECV after 36 weeks gestation reduced the number of breech deliveries and cesarean sections (32.5% in the study group compared with 51.4% in the control group) (P > 0.00001).

Acoustic Stimulation↗
PubMed1997

Preinduction cervical ripening: prostaglandin E2 gel vs hygroscopic mechanical dilator.

OBJECTIVES: To evaluate the efficacy and safety of hygroscopic mechanical dilators (Dilapan) for ripening the pregnant cervix prior to induction of labour at or near term and to compare it with an intracervical PGE2 gel (Prepidil). METHODS: One hundred and eighty-five women (69 nulliparae, 116 multiparae) at term with singleton pregnancies in cephalic presentation, who were scheduled for induction of labour in the labour ward at the National University Hospital, but had an unfavourable cervical score were randomized into 2 groups by random number table. In group 1 (Prepidil), 0.5 mg of PGE2 in 2.5 ml of triacetin gel was inserted into the endocervical canal. In women in group 2 (Dilapan) upto a maximum of 4 hygroscopic dilators were placed in the endocervical canal. If labour did not ensue at the end of 12 hours of ripening, the cervical score was assessed, amniotomy was performed and oxytocin commenced. Neonatal and obstetric outcome was compared, statistical analysis performed using Chi-square, and t-tests. RESULTS: Significantly more women in the group who received Dilapan for cervical ripening required amniotomy and oxytocin for induction of labour > 12 hours after priming compared with the group who received Prepidil (p < 0.001). Operative delivery for no progress and fetal distress respectively was similar in the 2 groups. The number of cases of hyperstimulation were higher in the Prepidil group but did not result in an increased incidence of operative deliveries for fetal distress. There was one neonatal death and one case of neonatal sepsis in the Dilapan group. Uterine rupture occurred in 1 woman who received Prepidil. CONCLUSION: Dilapan, a mechanical method of cervical ripening is as effective as the more widely accepted mode of ripening with an endocervical PGE2 gel in achieving vaginal delivery. Dilapan would be useful for cervical priming prior to induction of labour in places where prostaglandins are not available because of cost and the need for a cold chain.

Adult↗
PubMed1997

Is there a need to treat hypokalaemia associated with intravenous salbutamol infusion?

OBJECTIVES: To investigate the evolution of metabolic effects associated with intravenous salbutamol infusion given together with 2 doses of intramuscular steroids in the treatment of preterm labour. METHODS: Preterm labour was inhibited with an intravenous infusion of salbutamol in 8 women between 26 and 32(+6) weeks with normal singleton pregnancies. Serum glucose concentration, serum potassium, sodium and insulin concentrations, and total white cell count both during the infusion as well as post-therapy, were plotted against time. RESULTS: Intravenous salbutamol infusion administered at a rate required to inhibit uterine contractions in preterm labour causes a rise in serum glucose and plasma insulin concentrations. The serum glucose and plasma insulin levels peaked soon after cessation of therapy and took 2-3 hours to come to pre-infusion levels. The decline in serum potassium concentration was gradual and plateaued after 2 hours. Once the salbutamol infusion was stopped the potassium levels were back to normal by 2 hours. There is an increase in total white cell count within an hour of the initiation of therapy. CONCLUSION: There is no need to administer insulin for hyperglycaemia and/or potassium for hypokalaemia unless the patient is a known diabetic or when a patient needs immediate surgery.

Adrenergic beta-Agonists↗
PubMed1997

Fetal oxygen saturation during labour.

OBJECTIVE: To derive oxygen saturation by pulse oximetry (SpO2) values at each cervical dilation in labour in fetuses with normal neonatal outcome. PARTICIPANTS: One hundred and forty-five women at term in established labour with ruptured membranes and cervical dilation at least 2 cm who had normal delivery outcome. The infants had 5 minute Apgar scores > or = 7, birthweight > or = 2500 g, umbilical cord artery pH > or = 7.15 and did not require assisted ventilation or admission to neonatal intensive care. METHODS: Women were monitored continuously with cardiotocography and fetal pulse oximetry using the Nellcor N-400 fetal pulse oximeter and FS-14 fetal oxisensor till delivery. Labour was managed according to established protocol without recourse to SpO2 readings. RESULTS: There was a wide range of SpO2 values during labour in fetuses with normal outcome. Mean values averaged 50% +/- 10% throughout the first stage of labour, with lower ranges of SpO2 values above 30%. There was no significant difference in SpO2 readings at different cervical dilatations in the first stage of labour. Mean SpO2 values in the last 10 minutes before delivery were also not significantly different from those in the first stage of labour. CONCLUSION: The range of SpO2 in 115 healthy fetuses during normal labour was wide, but always above 30%. There was no trend of SpO2 values in this study of 115 fetuses with normal neonatal outcome.

Apgar Score↗
PubMed1997

Trial of scar.

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Cesarean Section, Repeat↗
PubMed1997

Intrapartum care.

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Anesthesia, Epidural↗
PubMed1997

Reasoning and delusions.

BACKGROUND: Delusions are assumed to reflect disordered reasoning. but with little empirical support. We attempted to study this in 16 relatively intelligent deluded patients and 16 normal volunteers. METHOD: Standard tests were used which required subjects to choose between logically fallacious and valid responses, both of which were plausible. The tests were: (a) conditional statements (if...then), (b) syllogisms (e.g. no A are C, some B are C, some C are not A), and (c) judgements of probability. All three tasks incorporated neutral and emotive content. RESULTS: Both normal and deluded subjects frequently made logical errors. With conditionals, deluded subjects tended to endorse fallacies more often than normal controls and this was accentuated when the content was emotive. Similarity, with syllogisms, the effect of emotional content on the endorsement of unbelievable responses was increased slightly in the deluded group. Finally, the deluded patients showed a trend to be less prone to the conjunction fallacy than normals, suggesting less reliance on existing schema. conclusions: Differences in reasoning between deluded patients and controls are surprisingly small. Patients are somewhat more prone to endorse invalid or fallacious responses, especially when emotive themes are involved.

Adult↗