Measuring blood pressure using an automated sphygmomanometer

An analysis of blood pressure measurement in a primary care hospital in Swaziland

Background

Measurement of blood pressure (BP) is done poorly because of both human and machine errors.

Aim

To assess the difference between BP recorded in a pragmatic way and that recorded using standard guidelines; to assess differences between wrist- and mercury sphygmomanometer-based readings; and to assess the impact on clinical decision-making.

Setting

Royal Swaziland Sugar Corporation Mhlume hospital, Swaziland.

Method

After obtaining consent, BP was measured in a pragmatic way by a nurse practitioner who made treatment decisions. Thereafter, patients had their BP re-assessed using standard guidelines by mercury (gold standard) and wrist sphygmomanometer.

Results

The prevalence of hypertension was 25%. The mean systolic BP was 143 mmHg (pragmatic) and 133 mmHg (standard) using a mercury sphygmomanometer; and 140 mmHg for standard BP assessed using wrist device. The mean diastolic BP was 90 mmHg, 87 mmHg and 91 mmHg for pragmatic, standard mercury and wrist, respectively. Bland Altman analyses showed that pragmatic and standard BP measurements were different and could not be interchanged clinically. Treatment decisions between those based on pragmatic BP and standard BP agreed in 83.3% of cases, whilst 16.7% of participants had their treatment outcomes misclassified. A total of 19.5% of patients were started erroneously on anti-hypertensive therapy based on pragmatic BP.

Conclusion

Clinicians need to revert to basic good clinical practice and measure BP more accurately in order to avoid unnecessary additional costs and morbidity associated with incorrect treatment resulting from disease misclassification. Contrary to existing research, wrist devices need to be used with caution.

[Nurses of adult intensive care unit: evaluation about direct and indirect blood pressure measurement]

This is a descriptive and cross-sectional study with the aim to evaluate and self-evaluate the knowledge of nurses from adult Intensive Care Units about direct and indirect blood pressure measurement. Fifty-four nurses from three Intensive Care Units were approached. They answered a self-administered questionnaire with 65 questions (40 related to blood pressure). Nurses had insufficient performance on the test that assessed knowledge (average score 4.6). Half of the sample felt dissatisfied with their knowledge about blood pressure. After answering the questionnaire the subjects self-rated their knowledge as regular (48.2%), bad (27.8%) and poor (9.3%) indicating they are aware of the importance for the subject to practice. The results show the need of urgent implementation of continuing education for this sample, since they are professionals who work directly with a priority vital sign on care to critical patients.

Sera from preeclampsia patients elicit symptoms of human disease in mice and provide a basis for an in vitro predictive assay

Early diagnosis and treatment of preeclampsia would significantly reduce maternal and fetal morbidity and mortality. However, its etiology and prediction have remained elusive. Based on the hypothesis that sera from patients with preeclampsia could function as a "blueprint" of causative factors, we describe a serum-based pregnancy-specific mouse model that closely mirrors the human condition as well as an in vitro predictive assay. We show that a single administration of human preeclampsia serum in pregnant IL-10-/- mice induced the full spectrum of preeclampsia-like symptoms, caused hypoxic injury in uteroplacental tissues, and elevated soluble fms-like tyrosine kinase 1 and soluble endoglin, markers thought to be related to the disease. The same serum sample(s) induced a partial preeclampsia phenotype in wild-type mice. Importantly, preeclampsia serum disrupted cross talk between trophoblasts and endothelial cells in an in vitro model of endovascular activity. Disruption of endovascular activity could be documented in serum samples as early as 12 to 14 weeks of gestation from patients who subsequently developed preeclampsia. These results indicate that preeclampsia patient sera can be used to understand the pregnancy-specific disease pathology in mice and can predict the disorder.