The Normal Difference in Bilateral Indirect Blood Pressure Recordings in Hypertensive Individuals

OBJECTIVE: If there is a significant dichotomy between bilateral systolic blood pressure determinations in both arms in hypertensive individuals, it is often taken as a sign of underlying pathology. The primary objective was to determine what the normal variation might be for a significant difference between blood pressures in both arms. A clinically significant difference was chosen as a systolic blood pressure value greater than 10 mm Hg between the upper extremities, as is commonly quoted at the bedside and in the literature. METHODS: Bilateral indirect blood pressure determinations were obtained in 100 subjects with hypertension in the sitting position. The blood pressure was obtained by two observers, one the recorder and the other who obtained the blood pressure but was blinded to the actual values taken. The order of blood pressure determination in the first arm was determined prior to the study from a table of random numbers. The coefficient of variation in obtaining the blood pressure in each arm was determined in 5 of the 100 subjects. The age, sex, and handedness of each individual were recorded as demographic variables. RESULTS: The average left and right systolic blood pressures were 139 +/- 22 and 141 +/- 22 mm Hg, respectively. The average left and right diastolic blood pressures were 78 +/- 12 and 79 +/- 13 mm Hg, respectively. There was no significant difference between left minus right systolic or diastolic differences (paired t-test). There was no significant difference between systolic or diastolic blood pressures between gender or between left- and right-handed individuals (nonpaired t-test). The average coefficients of variation for taking right and left arm systolic pressures were 2.90% and 1.32%, respectively. Eighteen subjects (18%) had differences in systolic blood pressure between both arms exceeding 10 mm Hg (10% to 26%, 95% confidence interval). CONCLUSIONS: Differences of more than 10 mm Hg in indirect systolic blood pressure recordings between arms are frequent in asymptomatic hypertensive individuals and do not per se indicate any pathologic condition. In the right clinical situation, differences that are noted should be repeated and should be added to the total clinical picture when used to determine whether a pathologic condition is present. Assuming no significant aortic or subclavian disease in the population tested, the specificity of the bilateral blood pressure test was 82%.     

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.     

两种体位对不同血压计血压测量值的影响

目的探讨坐位与卧位对电子血压计和汞柱血压计测量值差异的影响,以便在临床工作中正确使用电子血压计及指导患者正确地使用电子血压计进行自测血压。方法对142例查体患者在坐位和卧位时由2名护士分别使用电子血压计和汞柱血压计测量左、右臂的收缩压和舒张压,比较两种血压计血压测量值的差异。结果坐位时电子血压计和汞柱血压计所测得的左臂收缩压、左臂舒张压、右臂收缩压、右臂舒张压差异无统计学意义（t=-0．315,1．560,-1．472,1．156,P〉0．05）。卧位时电子血压计和汞柱血压计所测得的左臂收缩压差异无统计学意义（t=-0．370,P〉0．05）,但卧位时左臂舒张压、右臂收缩压、右臂舒张压差异有统计学意义（t=5．172,-5．402,2．979,P〈0．05）。结论坐位测量血压时,电子血压计可以替代汞柱血压计。     

Labetalol infusion in hypertensive emergencies

The antihypertensive effects of labetalol infusion (2 mg/min; maximal dose 150 mg) were evaluated in 22 subjects requiring rapid lowering of blood pressure because of severe hypertension, a hypertensive crisis after surgery, or before angiographic examination. Overall systolic and diastolic blood pressures were reduced from 201 +/- 4 to 164 +/- 4 mm Hg and from 123 +/- 3 to 107 +/- 3 mm Hg, respectively. By the end of the infusion, diastolic blood pressure in 16 (73%) subjects was lowered to less than or equal to 110 mm Hg. No adverse effects were encountered, but one subject had a transitory hypotensive episode that did not require treatment. Intravenous labetalol appears effective and well tolerated in the control of blood pressure in hypertensive emergencies.     

Effect of the 30 degree lateral recumbent position on pulmonary artery and pulmonary artery wedge pressures in critically ill adult cardiac surgery patients.

BACKGROUND: Despite demonstrated benefits of lateral positioning, critically ill patients may require prolonged supine positioning to obtain reproducible hemodynamic measurements. OBJECTIVES: TO determine the effect of 30 degree right and left lateral positions on pulmonary artery and pulmonary artery wedge pressures after cardiac surgery in critically ill adult patients. METHODS: An experimental repeated-measures design was used to study 35 patients with stable hemodynamics after cardiac surgery. Subjects were randomly assigned to 1 of 2 position sequences. Pulmonary artery and pulmonary artery wedge pressures were measured in each position. RESULTS: Measurements obtained from patients in the 30 degree left lateral position differed significantly (all Ps < .05) from measurements obtained from patients in the supine position for pulmonary artery systolic, end-diastolic, and mean pressures. Pulmonary artery wedge pressures did not differ significantly; however, data were available from only 17 subjects. The largest mean difference in pressures between the 2 positions was 2.0 +/- 2.1 mm Hg for pulmonary artery systolic pressures, whereas maximum differences for end-diastolic and pulmonary artery wedge pressures were 1.4 +/- 2.7 mm Hg and 1.6 +/- 2.4 mm Hg, respectively. Clinically significant position-related changes in pressure occurred in 12 (2.1%) of 581 pressure pairs. Clinically significant changes occurred in end-diastolic pressure in 2 subjects and in pulmonary artery wedge pressure in 1 subject. CONCLUSiONS: In patients with stable hemodynamics during the first 12 to 24 hours after cardiac surgery, measurements of pulmonary artery and pulmonary artery wedge pressures obtained in the 30 degree lateral and supine positions are clinically interchangeable.     

高血压患者不同体位动态血压的监测

目的了解高血压患者仰卧位、侧卧位、坐位、站立位动态血压测量有否不同。方法对51例动态血压监测的高血压患者,选用右上肢肱动脉测压法,分别测量不同体位的血压。结果仰卧位、左侧卧位、右侧卧位、坐位、站立位时的收缩压平均分别是152.10±14.55、129.21±14.92、150.42±15.54、149.87±14.84、147.85±12.67 mm Hg;舒张压平均分别是87.81±6.92、70.83±8.32、88.33±11.52、88.81±9.15、87.25±11.15 mm Hg。与仰卧位时动态血压测量的结果比较,左侧卧位时收缩压平均低22.89 mm Hg,舒张压平均低16.98 mm Hg,P<0.01;右侧卧位时收缩压平均低1.68 mm Hg,舒张压平均高0.52 mm Hg,P>0.05;坐位时收缩压平均低2.23 mm Hg,舒张压平均高1.00 mm Hg,P>0.05;站立位时收缩压平均低4.25 mm Hg,舒张压平均低0.56 mm Hg,P>0.05。结论高血压患者右侧卧位、坐位、站立位时与仰卧位时动态血压测量的结果无明显变化,左侧卧位时动态血压测量的结果显著低于仰卧位时动态血压测量的结果。     

Baseline hemodynamics in anesthetized landrace-large white swine: reference values for research in cardiac arrest and cardiopulmonary resuscitation models.

The use of swine in cardiopulmonary resuscitation (CPR) research has increased in the last decades. Landrace-Large White (LLW) swine are a farm breed of pigs. The aims of the present study were to describe the baseline hemodynamics of this breed and to demonstrate that it is suitable for CPR research. The systolic and diastolic pressures of the descending aorta (mean +/- 1 standard deviation; n = 29) were 111.72 +/- 13.61 and 79.03 +/- 12.08 mm Hg, respectively, whereas the mean systolic and diastolic pressures of the left ventricle were 108.97 +/- 12.06 and 8.88 +/- 1.81 mm Hg, respectively. The mean pressures of the right atrium were 10.93 +/- 1.36 mm Hg (systolic) and 4.10 +/- 1.01 mm Hg (diastolic), whereas the value obtained by using near-infrared spectroscopy to determine brain regional oxygen saturation was 64.55% +/- 3.88%. LLW can be considered a suitable breed for CPR research because of the close similarity of its hemodynamic values to those of humans.     

Treatment of hypertension in the elderly

We have evaluated the effectiveness of antihypertensive therapy for predominant systolic hypertension in 55 patients, aged 61 to 76 years, with untreated systolic blood pressures of at least 160 mm Hg and diastolic blood pressures less than 100 mm Hg. In this retrospective analysis, 41 of the patients had been treated with the centrally acting agent guanabenz (average dose 24 +/- 14 [SD] mg daily) given alone, and 14 had received a combination of guanabenz (17 +/- 10 mg daily) and hydrochlorothiazide (60 +/- 30 mg daily). After six months of therapy, each regimen significantly decreased both systolic and diastolic blood pressures. Moreover, there were no differences between the two treatment regimens in their antihypertensive efficacy, and there was no evidence of orthostatic effects. In both treatment groups, approximately 50% of the patients had excellent therapeutic responses (decrease in supine systolic blood pressure of at least 20 mm Hg). The main side effects of treatment were drowsiness and dry mouth, though these tended to be mild and of short duration. Thus, in predominant systolic hypertension in elderly patients, guanabenz, either alone or in combination with a diuretic, appears to be an effective and well tolerated form of treatment.     

Blood pressure decrease prior to initiating pharmacological therapy in nonemergent hypertension

In order to characterize the decrease in blood pressure that occurs in the emergency department (ED) setting in cases of nonemergent hypertension before beginning pharmacological therapy, 94 consecutive cases of hypertension seen at the University of Illinois Hospital were reviewed. Each patient in the analysis had a triage blood pressure recorded by the nursing staff and second blood pressure reading taken between 10 minutes and 2 hours after the triage pressure before pharmacological therapy was begun. Patients with diastolic pressures less than 90 mm Hg were excluded, as were patients with acute end-organ pathology secondary to hypertension. In the remaining 54 cases, the mean arterial pressure fell by 6% (P less than .003), the systolic pressure fell by 6% (P less than .022), and the diastolic pressure fell by 6.4% (P less than .003), suggesting that in nonemergent hypertension, a significant decrease in blood pressure occurs in the ED before pharmacological therapy is begun. The blood pressure decrease was not statistically different when sex and age were considered, but when patients were grouped into those with diastolic pressures between 90 mm Hg and 114 mm Hg and those with diastolic pressures greater than or equal to 115 mm Hg, there was a statistically significant decrease in systolic, diastolic, and mean arterial pressures only in patients with diastolic pressures greater than or equal to 115 mm Hg. Our findings suggest that patients with nonemergent hypertension do not always require immediate and aggressive pharmacological intervention in the ED setting and are best observed for a short period and then reassessed before beginning pharmacological therapy.     

Heart remodeling in case of isolated systolic arterial hypertension

Examination of 32 patients with isolated systolic arterial hypertension (office blood pressure 171.9 = -3.3/79.7 +/- 0.2 mm Hg) and 54 ones with systolic/diastolic hypertension) 179.8 +/- 3.9/114.8 +/- 1.9 mm Hg) showed that the former are characterized by isolated hypertrophy of interventricular septum, the latter by symmetric hypertrophy of the septum and free left ventricular wall. Septal hypertrophy affects the initial phase of diastolic filling of the left ventricle as appears from longer time of isovolume relaxation and low peak rate of early transmitral blood flow; it does not influence diastolic function of the right ventricle. Hypertrophy of the free left ventricular wall disturbs the final stage of early diastolic filling of both right and left ventricles manifest as increased duration of their slowed early filling.     

Nationwide efficacy-safety study of nebivolol in mildly hypertensive patients

Nebivolol has been adequately tested in clinical efficacy trials of patients with mild hypertension. Clinical efficacy trials or their meta-analyses did not accurately predict the outcome of subsequent large studies. The primary objective was to assess the efficacy/safety of nebivolol 5-10 mg daily in a nationwide study of patients with mild hypertension. Secondary objectives were (1) to compare efficacy/safety as monotherapy versus add-on therapy and (2) to assess the effect of nebivolol on ISH. This was an open-label, 6-week follow-up study of 6,356 patients with mild hypertension or ISH, as defined by the 1999 World Health Organization guidelines, recruited from 2,700 facilities. Previous monotherapies were continued except for beta-blockers. Results are reported as means+/-SDs. Intention-to-treat analysis is given. A total of 5,740 patients completed the study; of the withdrawals, 90% were lost for follow-up or were noncompliant, 38% were untreated before, 23% had beta-blockers. In the accumulated data, mean systolic and diastolic blood pressures fell by 24+/-14 and 13+/-9 mm Hg (both P<0.001). The differences between the blood pressure-reducing effects of nebivolol monotherapy and add-on therapy were not statistically significant: 28+/-16 and 22+/-14 mm Hg for systolic and 15+/-11 and 11+/-8 mm Hg for diastolic blood pressures. Adverse events were limited to 0.5% of the patients, no serious adverse events were observed. In the ISH patients, diastolic blood pressure fell by 4+/-6 mm Hg compared with 15+/-10 mm Hg in the no-ISH patients (P<0.01). Efficacy-safety effects of nebivolol in patients with mild hypertension can be generalized in a nationwide assessment. The efficacy of nebivolol as monotherapy and as the efficacy as add-on therapy are very similar. Nebivolol is highly efficacious in patients with ISH.     

Effects of delapril in combination with indapamide on blood pressure and left ventricular mass in elderly hypertensive patients

We present a single-blinded, placebo-controlled trial of the effects on blood pressure and left ventricular mass and of the safety of a combined antihypertensive treatment with delapril, a new nonsulfhydryl angiotensin-converting enzyme inhibitor, and indapamide, a sulfonamide diuretic. We studied 28 elderly patients aged 65-85 years (mean age, 69 +/- 1) with sitting systolic/diastolic blood pressure of 160-200/95-115 mm Hg (at the end of the placebo period). After a 2-week placebo run-in, patients took 30 mg delapril in combination with 1.25 mg indapamide once daily for 24 weeks. Twenty-four-hour ambulatory blood pressure was monitored and M- and B-mode echocardiography were performed before and after 24 weeks of treatment. Blood pressure decreased from 156 +/- 1.5/101 +/- 1 mm Hg before treatment to 133 +/- 1/73 +/- 1 mm Hg after treatment. The total blood pressure burden also decreased; the percentage of measurements with a systolic blood pressure > or = 140 mm Hg and a diastolic blood pressure > or = 90 mm Hg decreased from 48.7% +/- 5%/31.5% +/- 4.3% to 23.5% +/- 4%/20.5% +/- 2.9% (p < 0.0005 and p < 0.05). The area under the curve of the 24-hour blood pressure decreased from 250 +/- 41/103 +/- 21 mm Hg to 97 +/- 21/37 +/- 8.5 mm Hg (p < 0.001 and p < 0.005). The left ventricular mass index (LVMI) in the 15 patients with pretreatment left ventricular hypertrophy was reduced after therapy from 167.5 +/- 8.5 g/m 2 to 152.2 +/- 7.6 g/m 2 (p < 0.05). A positive correlation was observed between percent changes of the area under the curve of the 24-hour diastolic blood pressure and percent changes of LVMI (r = 0.6; p < 0. 05) in the 15 patients with left ventricular hypertrophy. Only 2 patients reported side effects: 1 developed skin rash and 1 developed headache. The safety of the treatment was confirmed by laboratory tests. In elderly hypertensive patients, the combination of delapril and indapamide at low doses reduced blood pressure and had favorable effects on LVMI with few side effects.     

Comparison of the effectiveness of a beta blocker (atenolol) and a diuretic (chlorthalidone) in black hypertensive patients

A double-blind crossover trial of atenolol and chlorthalidone was done in black Jamaican hypertensive patients. After an initial four weeks of single drug therapy, the beta blocker and thiazide diuretic were used in combination. Chlorthalidone at a daily dose of 25 mg produced a significant (P less than .05) fall in the mean systolic and diastolic pressures (19.4 mm Hg and 12.2 mm Hg, respectively); atenolol produced a significant fall in the diastolic blood pressure (6.5 mm Hg); and combination therapy produced a reduction in systolic and diastolic blood pressures (27.8 mm Hg and 17.8 mm Hg, respectively). The study showed that combination therapy using a low dose of thiazide diuretic and a beta blocker was synergetic, but that a thiazide was more effective than a beta blocker in lowering the blood pressure in black hypertensive patients.     

The effect of sodium on hemodynamic changes during coronary angiography with nonionic contrast media

To investigate the effect of sodium on cardiac hemodynamics, sodium chloride was added to nonionic contrast media to a 0.9% concentration and was compared with the standard media iohexol, iopamidol, and ioversol. Left coronary angiography was performed in 10 closed-chest, atrial-paced dogs with 10 ml injections of each preparation in a randomized and blinded fashion. The maximum changes in left ventricular systolic pressure, mean aortic pressure, left ventricular and diastolic pressure, and maximal rise of left ventricular pressure were measured. The left ventricular systolic pressure and mean aortic pressure decreased by 17 +/- 7 mm Hg and by 12 +/- 5 mm Hg with iohexol plus 0.9% NaCl, but only by 5 +/- 4 mm Hg and by 4 +/- 3 mm Hg with iohexol alone (p less than 0.001). The left ventricular and end diastolic pressure increased by 2.2 +/- 0.6 mm Hg with iohexol plus 0.9% NaCl, but did not change with iohexol alone (p less than 0.001). Left ventricular dp/dt decreased by 204 +/- 161 mm Hg/sec with iohexol plus 0.9% NaCl but increased by 392 +/- 122 mm Hg/sec with iohexol alone (p less than 0.001). Similar results were obtained from experiments with iopamidol versus iopamidol plus 0.9% NaCl and ioversol versus ioversol plus 0.9% NaCl. Ioversol plus 5% dextrose or ioversol plus 2.1% choline chloride (isomolar to ioversol plus 0.9% NaCl) produced a significant increase in left ventricular systolic pressure and left ventricular dp/dt (versus ioversol plus 0.9% NaCl, p less than 0.001). Thus, sodium, but not the osmolality or chloride, contributed to the negative inotropic effect of the contrast media.(ABSTRACT TRUNCATED AT 250 WORDS)     

Treatment of hypotension in pigs with an inspiratory impedance threshold device: a feasibility study

OBJECTIVE: An inspiratory impedance threshold device was evaluated in spontaneously breathing animals with hypotension to determine whether it could help improve systemic arterial pressures when fluid replacement was not immediately available. DESIGN: Prospective, randomized. SETTING: Animal laboratory. SUBJECTS: Thirty-nine female farm pigs (weight, 28-33 kg). INTERVENTIONS: A total of 39 anesthetized spontaneously breathing pigs were treated with an impedance threshold device, with cracking pressures from 0 to -20 cm H2O. Four separate experimental protocols were performed: protocol A, in which the hemodynamics of seven pigs were examined during application of an impedance threshold device at various levels of inspiratory impedance (-5, -10, -15, and -20 cm H(2)O), both before and after a severe, controlled hemorrhage to a systolic blood pressure of 50 - 55 mm Hg; protocol B, in which nine pigs bled to systolic blood pressure of 50 -55 mm Hg were treated with an impedance threshold device set at -12 cm H2O and were compared with nine others treated with a sham device; protocol C, in which the effects of the impedance threshold device on mixed venous gases were measured in seven hemorrhaged pigs; and protocol D, in which the effects of the impedance threshold device on cardiac output in seven hemorrhaged pigs were measured. METHODS AND MAIN RESULTS: During initial studies with both normovolemic and hypovolemic pigs, sequential increases in inspiratory impedance resulted in a significant increase in systolic blood pressure, whereas diastolic left ventricular and right atrial pressures decreased significantly and proportionally to the level of impedance. When comparing the sham vs. active impedance threshold device (-12 cm H(2)O) in hypotensive pigs, systolic blood pressure (mean +/- sem) with active impedance threshold device treatment increased from 70 +/- 2 mm Hg to 105 +/- 4 mm Hg (p <.01). Pressures in the control group remained at 70 +/- 4 mm Hg (p <.01). Cardiac output increased by nearly 25% (p <.01) with the active impedance threshold device when calculated using the mixed gas equation and when determined by thermodilution. CONCLUSIONS: These studies demonstrate that it is feasible to use a device that creates inspiratory impedance in spontaneously breathing normotensive and hypotensive pigs to increase blood pressure and enhance cardiopulmonary circulation in the absence of immediate fluid resuscitation. Further studies are needed to evaluate the potential long-term effects and limitations of this new approach to treat hypovolemic hypotension.     

Blood pressure lowering and potassium conservation by triamterene-hydrochlorothiazide and amiloride-hydrochlorothiazide in hypertension

Effects of once-daily doses of 50 mg triamterene with 25 mg hydrochlorothiazide and 5 mg amiloride with 50 mg hydrochlorothiazide were compared in a randomized, multicenter study of 84 adult subjects with mild to moderate hypertension (diastolic blood pressure 90 to 114 mm Hg). After a 3-wk placebo lead-in period, the subjects entered a 6-wk treatment period. The two drug regimens were compared with respect to antihypertensive effects and effects on serum potassium and magnesium levels during the final week of drug therapy, with the use of the last week of placebo therapy as a covariate. Both drug regimens substantially reduced mean supine systolic and diastolic blood pressures to well within normal limits; there was no significant difference the two groups. Twenty-four of the 41 subjects receiving triamterene-hydrochlorothiazide (59%) and 29 of the 43 patients receiving amiloride-hydrochlorothiazide (67%) had diastolic blood pressure less than 90 mm Hg at week 9. Five subjects receiving amiloride-hydrochlorothiazide (12%) and two subjects receiving triamterene-hydrochlorothiazide (5%) had hypokalemia (serum potassium level less than 3.5 mEq/l) at week 9. The average decrease in serum potassium levels during amiloride-hydrochlorothiazide therapy (-0.33 +/- 0.08 mEq/l) was greater than that after triamterene-hydrochlorothiazide (- 0.08 +/- 0.07 mEq/l). Serum magnesium levels were not changed by either regimen. Weight loss was greater in the amiloride-hydrochlorothiazide group than in the triamterene-hydrochlorothiazide group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Right ventricular infarction: recognition and assessment of its hemodynamic significance by two-dimensional echocardiography

To evaluate the ability of two-dimensional echocardiographic indexes to determine the hemodynamic significance of the right ventricular infarction, 24 patients with electrocardiographic evidence of right ventricular infarction were studied. Hemodynamic significance was defined as a jugular venous pressure greater than 17 cm H2O or a right atrial pressure greater than 13 mm Hg. Patients with hemodynamically significant right ventricular infarctions (group I, n = 9) had a 56% incidence of hypotension (blood pressure less than 90 mm Hg) with a mean systolic blood pressure of 93 +/- 23 mm Hg, whereas patients with nonhemodynamically significant right ventricular infarctions (group II, n = 15) had no hypotension and a mean systolic blood pressure of 121 +/- 18 mm Hg (p less than 0.01). The ratio of right atrial to pulmonary capillary wedge pressure was 1.1 +/- 0.6 in group I and 0.6 +/- 0.2 in group II (p less than 0.05). Echocardiography demonstrated right ventricular free wall motion abnormalities in seven patients in group I and in 10 patients in group II. The descent of the right ventricular base was 0.7 +/- 0.2 cm in group I, 1.3 +/- 0.4 cm in group II, and 2.0 +/- 0.2 cm in a group of 20 normal control patients (p less than 0.001 for all comparisons). The respiratory caval index (percentage of collapse of the inferior vena cava with inspiration) was 22% +/- 11% in group I, 45% +/- 15% in group II, and 64% +/- 17% in the control subjects (p less than 0.05 for all comparisons).(ABSTRACT TRUNCATED AT 250 WORDS)     

The natural history of medication compliance in a drug trial: limitations of pill counts

To assess medication compliance over time, we prospectively performed pill counts among 121 ambulatory hypertensive subjects for less than or equal to 12 months. Prescribed regimens consisted of pinacidil or hydralazine administered four times a day and of secondary drugs administered up to twice daily. Surreptitious pill counts occurred every 1 to 12 weeks. Among a middle-aged subject group that had been selected for high rates of compliance, we observed mean compliance rates that approximated 100%. We noted marked intrasubject and intersubject variability for any one medication, between medications, and over time. From baseline blood pressures (+/- SE) of 155.5 +/- 1.9/97.3 +/- 1.0 mm Hg, subsequent mean blood pressures varied by compliance subgroup: "hypocompliers" (less than 80%), 151.3/91.0 mm Hg; "hypercompliers" (greater than or equal to 120%), 147.6/91.4 mm Hg; and "eucompliers" (80% to 119%), 143.3/88.5 mm Hg (systolic blood pressure: F1,52 = -220.9, NS; diastolic blood pressure: F1,52 = -121.4, NS). We concluded that weekly pill counts indicated marked intersubject and intrasubject variability, obscured by long-term averages; that compliance lapses appeared to be random; and that excessive medication-taking was the most consistent with "pill dumping."     

Intraosseous Pressure Monitoring in Healthy Volunteers

Study Objective: Invasively monitoring blood pressure through the IO device has not been thoroughly demonstrated. This study attempted to establish baseline values of IO pressure in a healthy human population. Methods: This was a prospective, healthy volunteer, observational study. Participants had two IO devices placed (humerus and tibia), and participant IO pressures, vital signs, and pain scores were monitored for up to 60 minutes. Participants were contacted at 24-hours and 7 days post-testing to assess for adverse events. Summary statistics were calculated for systolic, diastolic, and mean humeral and tibial IO pressure. The ratio of IO to non-invasive blood pressure was calculated, and Bland Altman plots were created. The slope (linear) of the mean humeral and the tibial IO pressures were also calculated. Results: Fifteen subjects were enrolled between April and July 2015. Fourteen of 15 humeral IOs were placed successfully (93.3%) and all 15 of the tibial IOs were placed successfully. Mean tibial systolic, diastolic, and mean IO pressure were 55.8 ± 27.9, 49.3 ± 27.1, and 48.4 ± 29.4 mm Hg, respectively. Humeral systolic, diastolic, and mean IO pressure were 32.9 ± 16.0, 27.4 ± 15.2, and 24.5 ± 14.3 mm Hg. The mean tibial IO pressure was 52.5% ± 32.0% of external cuff pressure ratio. The mean humeral IO pressure was 26.5% ± 15.2% of the external mean blood pressure. The Bland Altman plots showed an inconsistent relationship between the systolic and diastolic cuff pressure and the IO pressures. We observed a 1% per minute decrease in IO pressure from the initial placement until the final reading. Conclusions: Intraosseous pressure readings can be obtained in healthy human volunteers. However, absolute IOP values were not consistent between subjects. Future research may determine how IO pressure can be used to guide therapy in ill and injured patients.     

缬沙坦对高血压患者左心室壁厚度和舒张功能的影响

目的观察缬沙坦的降压效果,及其对左心室壁厚度和舒张功能的影响。方法对55例高血压患者使用缬沙坦降压治疗6个月,观察其降压效果及对左心室功能影响。结果治疗6个月后患者血压明显下降,收缩压平均下降27.7 mm Hg(1 mm Hg=0.133 kPa),舒张压平均下降16.4 mm Hg,左心室壁厚度及左心室舒张末期内径也明显下降。结论缬沙坦降压效果较好,且不良反应轻微,并可逆转左心室肥厚及改善左心室舒张功能。