Routine antenatal ultrasound in low- and middle-income countries: first look - a cluster randomised trial

OBJECTIVE

Ultrasound is widely regarded as an important adjunct to antenatal care (ANC) to guide practice and reduce perinatal mortality. We assessed the impact of ANC ultrasound use at health centres in resource-limited countries.

DESIGN

Cluster randomised trial.

SETTING

Clusters within five countries (Democratic Republic of Congo, Guatemala, Kenya, Pakistan, and Zambia) METHODS: Clusters were randomised to standard ANC or standard care plus two ultrasounds and referral for complications. The study trained providers in intervention clusters to perform basic obstetric ultrasounds.

MAIN OUTCOME MEASURES

The primary outcome was a composite of maternal mortality, maternal near-miss mortality, stillbirth, and neonatal mortality.

RESULTS

During the 24-month trial, 28 intervention and 28 control clusters had 24 263 and 23 160 births, respectively; 78% in the intervention clusters received at least one study ultrasound; 60% received two. The prevalence of conditions noted including twins, placenta previa, and abnormal lie was within expected ranges. 9% were referred for an ultrasound-diagnosed condition, and 71% attended the referral. The ANC (RR 1.0 95% CI 1.00, 1.01) and hospital delivery rates for complicated pregnancies (RR 1.03 95% CI 0.89, 1.20) did not differ between intervention and control clusters nor did the composite outcome (RR 1.09 95% CI 0.97, 1.23) or its individual components.

CONCLUSIONS

Despite availability of ultrasound at ANC in the intervention clusters, neither ANC nor hospital delivery for complicated pregnancies increased. The composite outcome and the individual components were not reduced.

TWEETABLE ABSTRACT

Antenatal care ultrasound did not improve a composite outcome that included maternal, fetal, and neonatal mortality.

Specialty choices of medical students and house officers in Karachi, Pakistan

Unerstanding patterns of career choices inmedicine is importnat for educators and policy-makers to plan the supply of specialists. This study analysed the career choices made by medical students and house officers in 2 private and 2 public medical schools in Karachi, Pakistan. An anonymous, self-administered and gynaecology were the 4 highest ranked specialties, with internal medicine ranked top as both the 1st and 2nd choice. Internal medicine was the 1st choice for significantly more students in public than private medical colleges (22.2% versus 1l4.9%). Students from private medical institutions chose a wider range of specialties than those from publicly-funded colleges. A high proportion of medical students and graduates in Karachi favour the same medical specialties, which may lead to saturation in those areas of specialization.

Weight change associated with valproate and lamotrigine monotherapy in patients with epilepsy

OBJECTIVE

To compare the incidence and magnitude of change in body weight associated with lamotrigine or divalproex sodium monotherapy in patients with epilepsy.

METHODS

A randomized, double-blind study with 8-week escalation phase and 24-week maintenance phase was conducted. Target maintenance dosage was 200 mg/day (lamotrigine) and 20 mg/kg/day (valproic acid), with adjustment from 100 to 500 mg/day (lamotrigine) and 10 to 60 mg/kg/day (valproate) based on investigators' judgment. Eligible patients were > or = 12 years old with new-onset or previously diagnosed partial or generalized seizures. Weight change was primary and seizure frequency and tolerance were secondary outcome measures.

RESULTS

For the lamotrigine group, 65 patients (mean age 34.5 years) were investigated; for the valproate group, 68 patients (mean age 30.1 years) were investigated. Weight remained stable in lamotrigine-treated patients. Significant weight gain occurred in valproate-treated patients by the 10th week of treatment; weight continued to increase throughout the study. After 32 weeks of treatment, mean weight gain was significantly higher in valproate-treated (12.8 +/- 9.3 lb) than lamotrigine-treated (1.3 +/- 11.9 lb) patients. Similar proportions of patients in lamotrigine (29%) and valproate (26%) groups were seizure-free. Overall frequency of adverse events was similar between the two treatment groups. Mean time to withdrawal from the study due to adverse events was 103 +/- 70 days for the lamotrigine group and 79 +/- 48 days for the valproate group.

CONCLUSION

Valproate monotherapy was associated with significantly greater weight gain than lamotrigine monotherapy. Weight gain associated with valproate was significant within 10 weeks after initiating therapy and continued throughout the study. Efficacy of lamotrigine was comparable with that of valproate; lamotrigine tended to be better tolerated.

Contributions of GABAA receptors and GABAC receptors to acetylcholine release and directional selectivity in the rabbit retina

GABA is a major inhibitory neurotransmitter in the mammalian retina and it acts at many different sites via a variety of postsynaptic receptors. These include GABAA receptors and bicuculline-resistant GABAC receptors. The release of acetylcholine (ACh) is inhibited by GABA and strongly potentiated by GABA antagonists. In addition, GABA appears to mediate the null inhibition which is responsible for the mechanism of directional selectivity in certain ganglion cells. We have used these two well-known examples of GABA inhibition to compare three GABA antagonists and assess the contributions of GABAA and GABAC receptors. All three GABA antagonists stimulated ACh release by as much as ten-fold. By this measure, the ED50s for SR-95531, bicuculline, and picrotoxin were 0.8, 7.0, and 14 microM, respectively. Muscimol, a potent GABAA agonist, blocked the effects of SR-95531 and bicuculline, but not picrotoxin. This indicates that SR-95531 and bicuculline are competitive antagonists at the GABAA receptor, while picrotoxin blocks GABAA responses by acting at a different, nonreceptor site such as the chloride channel. In the presence of a saturating dose of SR-95531 to completely block GABAA receptors, picrotoxin caused a further increase in the release of ACh. This indicates that picrotoxin potentiates ACh release by a mechanism in addition to the block of GABAA responses, possibly by also blocking GABAC receptors, which have been associated with bipolar cells. All three GABA antagonists abolished directionally selective responses from ON/OFF directional-selective (DS) ganglion cells. In this system, the ED50S for SR-95531, bicuculline, and picrotoxin were 0.7 microM, 8 microM, and 94.6 microM, respectively. The results with SR-95531 and bicuculline indicate that GABAA receptors mediate the inhibition responsible for directional selectivity. The addition of picrotoxin to a high dose of SR-95531 caused no further increase in firing rate. The comparatively high dose required for picrotoxin also suggests that GABAC receptors do not contribute to directional selectivity. This in turn suggests that feedforward GABAA inhibition, as opposed to feedback at bipolar terminals, is responsible for the null inhibition underlying directional selectivity.

Vagus nerve stimulation for treatment of partial seizures: 1. A controlled study of effect on seizures. First International Vagus Nerve Stimulation Study Group

Vagus nerve stimulation (VNS) was shown to reduce seizure frequency in refractory epilepsy patients in two pilot studies. Based on these results, a multicenter, prospectively randomized, parallel, double-blind study of patients with refractory partial seizures was initiated. After a 12-week baseline period, identical vagus nerve stimulators were implanted and patients randomized to either a high or low 14-week VNS treatment paradigm. The primary objective was to demonstrate that high VNS (therapeutic parameters) was more effective in reducing partial seizure frequency than was low VNS (less or noneffective parameters). Patients continued receiving antiepileptic drugs (AEDs) with plasma concentrations held constant throughout the study. We report results of the first 67 patients to exit the 14-week acute phase. After 14 weeks of VNS, 31 patients receiving high VNS experienced a mean seizure frequency percentage reduction of 30.9%, which was statistically significant as compared with the mean seizure frequency percentage reduction of 11.3% in 36 patients receiving low VNS (p = 0.029, t test; p = 0.036, Wilcoxon rank-sum test). In addition to the significant intragroup p-values, mean seizure frequency percentage change reached statistical significance for high VNS (p < 0.001) but not low VNS (p = 0.072) as compared with baseline. Twelve of 31 (38.7%) patients receiving high VNS achieved at least 50% reduction in seizure frequency whereas 7 of 36 (19.4%) patients receiving low VNS experienced at least 50% reduction after 14 weeks. The implant procedure and VNS therapy were well tolerated. Our study confirmed the effectiveness of VNS as treatment for epilepsy patients with refractory partial seizures.

Valproate-associated pancreatitis

To assess the clinical characteristics of valproate (VPA)-associated pancreatitis, information from three sources was gathered: (a) a survey among 507 physicians with a special interest in treatment of epilepsy, (b) a review of the authors' patient population, and (c) a review of the literature. Of 366 physicians answering the survey, 53 (14.5%) reported a case of pancreatitis. Thirty-nine cases were available for review (24 from the medical literature, 12 from the survey, and 3 from the authors). Pancreatitis appeared to be more frequent in young persons (mean age 16.4 years) but may occur at any age. The highest risk appears to exist during the first months of treatment: 43.8% of the cases developed during the first 3 months, and 68.8% developed during the first year. Seventy-six percent of patients were receiving polytherapy, and 41% had some form of associated chronic encephalopathy. In most patients, the reaction was rapidly reversible when VPA was discontinued. It was severe in 6 patients, with 3 deaths reported. Rechallenge with VPA was attempted in 9 patients, with a high incidence of relapses. Asymptomatic elevation of serum amylase in patients receiving VPA was reported by 40 (10.9%) of the physicians surveyed. Awareness of the problem and early discontinuation of VPA may be effective in preventing serious reactions.

MR imaging in chronic partial epilepsy: role of contrast enhancement

Gadopentetate dimeglumine was administered prospectively to 150 consecutive patients who had had partial epilepsy for longer than 1 year to determine whether it is routinely indicated for the diagnosis of this disorder. MR abnormalities correlating with clinical or electroencephalographically documented seizure foci were detected in 69 cases (46%). Contrast enhancement was seen in 33 of these lesions, but the presence of enhancement altered the original radiologic diagnosis in only 17 (11%) of 150 cases. In only two cases (1%) did contrast administration reveal lesions that were not definitely apparent on the unenhanced images. The utility of contrast administration could not be predicted on the basis of seizure type (simple or complex) or the presence of secondary generalization. Gadopentetate dimeglumine does not appear to be routinely required in the MR workup of patients with chronic partial epilepsy. It should be used selectively to clarify or better define the nature of abnormalities encountered on unenhanced images.

Catastrophic neurologic signs due to drug interaction: Tegretol and Darvon

Eight cases of carbamazepine toxicity from interaction with propoxyphene are reported. Serum concentrations of carbamazepine increased up to sixfold. All patients were symptomatic and two were hospitalized. Practitioners prescribing propoxyphene acutely for pain should be aware of this significant interaction.