Wrist blood pressure-measuring devices: a comparative study of accuracy with a standard auscultatory method using a mercury manometer

BACKGROUND: In this study, we compared two wrist blood pressure-measuring devices, the Omron RX and the Nissei WS-310, against a mercury manometer. METHOD: A total of 152 subjects attending an out-patient hypertensive clinic were recruited from a randomized blood pressure survey, 87 patients (mean 44.4 +/- 14.5 years of age) being selected according to the Association for the Advancement of Medical Instrumentation/British Hypertension Society standards. Device validation was assessed through the use of sequential same-arm readings compared with readings taken using a mercury sphygmomanometer by the two trained observers. RESULTS: There were no differences between the observers and the monitors for diastolic readings (2.8 +/- 4.8 mmHg for the Omron and 4.2 +/- 6.4 mmHg for the Nissei) according to the Association for the Advancement of Medical Instrumentation standards. The largest standard deviations -- 8.3 mmHg for the Omron and 8.8 mmHg for the Nissei, respectively -- were seen for systolic readings recorded by the observers and the monitors. According to the British Hypertension Society standards, the Omron achieved an A grade for diastolic readings and a B grade for systolic readings within 5 and 10 mmHg. The Nissei monitor achieved an A grade for diastolic readings and a B grade for systolic readings within 5 and 10 mmHg. CONCLUSION: Patients found the wrist oscillometric devices that we tested to be comfortable and easy to use. These devices are appropriate for measuring diastolic blood pressure according to the standards, but the reliability of both devices decreased when measuring systolic blood pressure.     

The Pakistan National Emergency Department Surveillance Study (Pak-NEDS): Introducing a pilot surveillance

Background

Evidence-based decision making is essential for appropriate prioritization and service provision by healthcare systems. Despite higher demands, data needs for this practice are not met in many cases in low- and middle-income countries because of underdeveloped sources, among other reasons. Emergency departments (EDs) provide an important channel for such information because of their strategic position within healthcare systems. This paper describes the design and pilot test of a national ED based surveillance system suitable for the Pakistani context.

Methods

The Pakistan National Emergency Department Surveillance Study (Pak-NEDS) was pilot tested in the emergency departments of seven major tertiary healthcare centres across the country. The Aga Khan University, Karachi, served as the coordinating centre. Key stakeholders and experts from all study institutes were involved in outlining data needs, development of the study questionnaire, and identification of appropriate surveillance mechanisms such as methods for data collection, monitoring, and quality assurance procedures. The surveillance system was operational between November 2010 and March 2011. Active surveillance was done 24 hours a day by data collectors hired and trained specifically for the study. All patients presenting to the study EDs were eligible participants. Over 270,000 cases were registered in the surveillance system over a period of four months. Coverage levels in the final month ranged from 91-100% and were highest in centres with the least volume of patients. Overall the coverage for the four months was 79% and crude operational costs were less than $0.20 per patient.

Conclusions

Pak-NEDS is the first multi-centre ED based surveillance system successfully piloted in a sample of major EDs having some of the highest patient volumes in Pakistan. Despite the challenges identified, our pilot shows that the system is flexible and scalable, and could potentially be adapted for many other low- and middle-income settings.

     

Minimizing Electromagnetic Interference from Surgical Instruments on Electromagnetic Surgical Navigation

Background

Electromagnetic computer-assisted surgery (EM-CAS) can be affected by various metallic or ferromagnetic factors.

Questions/purposes

We determined to what extent metals interfere with accuracy and identified measures to prevent interference from occurring.

Methods

Using an EM-CAS system, we made six standard measurements of tibiofemoral position and alignment on a surrogate knee. A stainless steel mallet was positioned 10 cm from the stylus, and then 10 cm from the localizer to create errors attributable to electromagnetic interference. The experiment was repeated with bars of different metals placed 10 cm from the stylus.

Results

The maximum errors recorded with a mallet were: varus/valgus alignment, −2.7° and 2.4°; flexion/extension, −5.8° and 3.0°; lateral resection level, −3.1 and 7.5 mm; and medial resection level, −4.0 and 2.3 mm, respectively. The smallest errors were recorded with cylinders of titanium, cobalt-chrome alloy, and stainless steels. When moved more than 10 cm away from the stylus, errors became negligible.

Conclusions

The accuracy of EM navigation systems is affected substantially by the size, type, proximity, and shape of metal objects.

Clinical Relevance

Stainless steel objects, such as cutting blocks and trial prostheses, should be kept more than 10 cm from EM-CAS instruments to minimize error.     

Ewing's sarcoma of the calcaneus with metastases to the tibia and fibula

Ewing's Sarcoma of the calcaneus has been infrequently reported in literature. Metastases to the adjoining tibia and fibula have been reported even more rarely. We report a patient who, at the time of presentation, showed gross destruction of the calcaneus and metastases to the ipsilateral tibia and fibula.     

Irritant potential of some constituents from the seeds of Caesalpinia bonducella (L.) Fleming

The irritant potential of four triterpenoids, isolated for the first time from the seeds of Caesalpinia bonducella, identified as f -amyrin [12-ursen-3 g -ol], g -amyrin [12-oleanex-3 g -ol], lupeol [lup-20(29)-en-3 g -ol] and lupeol acetate [lup-20(29)-en-3 g -yl acetate] was investigated by open mouse ear assay, evaluating their ID₅₀ (irritant dose in 50% animals) after acute effects and by irritant units (IU) after chronic effects. f -Amyrin, lupeol acetate and g -amyrin were the most potent and persistent irritant compounds with red weals of 1.5-2.1 cm diameter areas of the animal skin and with lowest ID₅₀ =0.078, 0.186 and 0.190 mg/10 w l after 1.5, 2.10 and 3.5 h, respectively. Their reactions lasted for 24 h with IU=2.5; 0.312 and 1.25 mg/10 w l, respectively. Lupeol was the least irritant and least persistent compound with ID₅₀ =0.603 mg/10 w l after 4.5 h. Its reaction subsided before 24 h.     

p53 gene mutations in oropharyngeal carcinomas: A comparison of solitary and multiple primary tumours and lymph-node metastases

Despite the steadily increasing number of patients suffering from squamous-cell carcinomas of the oropharyngeal region, little is known about the molecular steps involved in the induction of these neoplasms. We investigated oropharyngeal cancers from 38 patients for mutations in the p53 tumour-suppressor gene. The majority of patients (74%) had a history of tobacco and alcohol abuse. Five had lymph-node metastases, 3 had multiple primary carcinomas and 2 presented with multiple primary tumours and lymph-node metastases. Exons 5 through 8 of the p53 gene were screened by single-strand conformation polymorphism analysis followed by direct DNA sequencing. A total of 16 tumours (42%) contained point mutations which were scattered throughout exons 5 to 8. Most mutations (56%) were transitions, predominantly G→A. Among the transversions, G→T mutations prevailed; these have also been found in smoking-related lung cancer. One carcinoma of the soft palate showed a mutation which was retained in a lymph-node metastasis. In another patient, 2 primary carcinomas had different mutations, indicating that they had developed independently. Similar results were obtained in a case with a p53 mutation in the third of 3 primary tongue carcinomas which developed over a period of 23 years. One lymph-node metastasis had a 12-bp deletion which was not detected in any of the primary malignancies. The frequent occurrence of p53 mutations in oropharyngeal carcinomas supports the view that they play a role in the initiation or progression of the malignant phenotype.