Assessment of blood pressure discrepancies in third-trimester hypertensive gravidas.

Previous studies have associated hypertension with discrepancies between right arm and left arm blood pressure (BP) measurements. The purpose of this study was to determine if there were clinically (defined as > or = 10 mm Hg disparity) and statistically significant differences between right arm and left arm BP measurements (systolic, diastolic, or mean) in 34 third-trimester hypertensive gravidas. Thirty-four third-trimester normotensive gravidas were used as controls. No subjects were in active labor. This study used a cross-sectional, 2-group design with convenience sampling. The protocol for BP measurement followed guidelines of the American Heart Association and the instrument manufacturer. The results showed a greater range in BP differences between arms for the hypertensive group in the systolic (0.67-26.67 mm Hg) and mean (0.25-67 mm Hg) pressures compared with the normotensive group (systolic, 0-14.33 mm Hg; mean, 0-12 mm Hg). The mean difference in BP between arms was greater for the hypertensive group compared with the normotensive group. Using a 1-tailed t test, the mean difference was statistically significant (P < or = .05) for the systolic pressure (P = .027) and for the mean pressure (P = .022), but not the diastolic pressure (P = .168). The frequency of clinically significant differences (> or = 10 mm Hg) was greater for the hypertensive group than for the normotensive group (13 vs 4). These differences in frequencies were not statistically significant with chi-square analysis (systolic, P = .074; diastolic, P = .303; mean, P = .303). These findings indicated BP discrepancies between arms exist in both normotensive and hypertensive gravidas, with a greater range and frequency of differences in the hypertensive group. This study supports the American Heart Association's recommendation of bilateral BP assessment.

Changes in oxygen saturation during weaning from short-term ventilator support after coronary artery bypass graft surgery.

OBJECTIVE: To evaluate changes in oxygenation as measured by pulse oximetry (SpO2) and saturated venous oxygenation (SvO2) during weaning from mechanical ventilator support. DESIGN: Exploratory, pilot study. SETTING: Cardiovascular intensive care unit in a private 691-bed acute care medical center in the South. SUBJECTS: Ten adults between 50 and 76 years of age who had uncomplicated coronary artery bypass graft surgery. OUTCOME MEASURES: SpO2 and SvO2 obtained at start of each weaning event and each minute for 5 minutes thereafter. METHOD: Five discrete events associated with the unit's weaning protocol were studied: ventilator adjustments, continuous positive airway pressure trial, respiratory mechanics, removing continuous positive airway pressure and suctioning, and extubation. Weaning events, initiated by unit staff members, were based on subjects' arterial blood gases, SpO2, respiratory rate, blood pressure, heart rate, level of alertness, and respiratory effort. RESULTS: Both SpO2 and SvO2 changed with weaning. For some subjects these changes were clinically important: SvO2 fell by 10% or more, and SpO2 fell to or below 90%. The assessment parameters guiding the weaning process resulted in some weaning events being initiated when SvO2 was at or below 60%. CONCLUSIONS: Measures of SpO2 and SvO2 are sensitive to changes in oxygenation status during weaning. Although more study is needed, SvO2 measures provide valid information about oxygen status and can be used to guide weaning.