An assessment of introducers used for airway management

Different introducers are available to assist with tracheal intubation. Subtle differences in the design of introducers can have a marked effect on safety and performance. The Difficult Airway Society's Airway Device Evaluation Project Team proposal states that devices should only be purchased for which there is at least a case-control study on patients assessing airway devices. However, resources are not currently available to carry out a case-control study on all introducers available on the market. This study comprised a laboratory and manikin-based investigation to identify introducers that could be suitable for clinical investigation. We included six different introducers in laboratory-based assessments (design characteristics) and manikin-based assessments involving the participation of 30 anaesthetists. Each anaesthetist attempted placement in the manikin's trachea with each of the six introducers in a random order. Outcomes included first-time insertion success rate; insertion success rate; number of attempts; time to placement; and distance placed. Each anaesthetist also completed a questionnaire. First-time insertion success rate depended significantly on the introducer used (p = 0.0016) and varied from 47% (Armstrong and P3) to 77% (Intersurgical and Frova). Median time to placement (including oesophageal placement) varied from 10 s (Eschmann and Frova) to 20 s (P3) (p = 0.0025). Median time to successful placement in the trachea varied from 9 s (Frova) to 22 s (Armstrong) (p = 0.037). We found that the Armstrong and P3 devices were not as acceptable as other introducers and, without significant improvements to their design and characteristics, the use of these devices in studies on patients is questionable. The study protocol is suitable for differentiating between different introducers and could be used as a basis for assessing other types of devices.

Meeting report on the Bellagio Conference ‘prevention of vascular diseases in the emerging world: An approach to global health equity’

Representatives from five international organizations (International Society of Nephrology, World Heart Federation, International Diabetes Federation, International Atherosclerosis Federation, and International Society of Hypertension) participated in a strategic planning workshop in December 2005 in Bellagio, Italy sponsored by the Rockefeller Foundation. There were equal representatives from developed and developing countries. Global perspectives on diabetes and cardiovascular and renal diseases were presented, with special emphasis on China, India, Latin America, and Africa. The rationale and effectiveness of preventive measures were discussed. It was apparent that measures for primary prevention and early intervention for all the chronic vascular diseases are similar. The five organizations agreed that an integrated global approach to chronic vascular diseases is needed. They resolved to collaborate and work towards an integrated approach to chronic vascular diseases with the establishment of a 5-year plan for the prevention and treatment of chronic vascular diseases, including public advocacy, advising international and national agencies, and improving education and the practice of established approaches.

[Serum uric acid--a cardiovasular risk factor?]

Serum uric acid represents an important, independent risk factor for cardiovascular and renal disease in patients with hypertension, heart failure, or diabetes. Elevated serum uric acid is highly predictive of mortality in patients with heart failure or coronary artery disease and of cardiovascular events in patients with diabetes. Although the mechanism(s) by which uric acid may play a pathogenetic role in cardiovascular disease is unclear, hyperuricemia is associated with deleterious effects on endothelial dysfunction, oxidative metabolism, platelet adhesiveness, hemrheology, and aggregation. Whether a reduction in uric acid impacts CV and renal disease remains to be determined. However, recent findings from LIFE in hypertensive patients with LVH suggest the possibility that a treatment-induced decrease in serum uric acid may indeed attenuate cardiovascular risk. Almost one third of the treatment benefit of a losartan-based versus atenolol-based therapy on the composite endpoint (death, myocardial infarction, or stroke) may be ascribed to differences in achieved serum uric acid levels. Clearly, randomized clinical trials are needed to investigate further the long-term cardioprotective benefits issue of reducing hyperuricemia in hypertensive patients.

Replacement-ready? Succession planning tops health care administrators' priorities

Nurses' increasing age coupled with health care's rapidly changing environment moves succession planning, originally only a business sector tool, to a top administrative priority. Through active support of your facility's executive leadership and a clear linkage to long range organization objectives, you can implement this progressive procedure.

Antihypertensive efficacy and safety of losartan alone and in combination with hydrochlorothiazide in adult African Americans with mild to moderate hypertension

BACKGROUND

African Americans with hypertension, particularly those with more severe blood pressure elevations, are generally less responsive to monotherapy from any antihypertensive class. These patients usually require treatment with drugs from > or = 2 antihypertensive classes to achieve adequate blood pressure control.

OBJECTIVE

The purpose of this study was to assess the antihypertensive efficacy and safety of losartan alone and in combination with hydrochlorothiazide (HCTZ) in African American adults with mild to moderate hypertension.

METHODS

In this 12-week, multicenter, double-blind, randomized, parallel-group, placebo-controlled study, African American patients were randomized in a 3:3:1 ratio to I of 3 treatment groups: placebo, losartan monotherapy (50 to 150 mg), or losartan plus HCTZ (50/0 to 50/12.5 to 100/25 mg). Doses were titrated at weeks 4 and 8 if sitting diastolic blood pressure (SiDBP) was > or = 90 mm Hg. Safety was assessed by determining the incidence of clinical and laboratory Adverse events and evaluating mean changes in pulse, body weight, electrocardiographic parameters, and laboratory test results.

RESULTS

A total of 440 patients were randomized-188 to placebo, 193 to losartan monotherapy, and 59 to losartan/HCTZ; 391 completed the study. At week 12, the response rate with losartan monotherapy was 45.8%, with a significant (P < or = 0.01) lowering in mean SiDBP by 6.6 mm Hg compared with placebo; the response rate with placebo was 27.2%, with a mean SiDBP reduction of 3.9 mm Hg. Sitting systolic blood pressure (SiSBP) was significantly lowered with losartan monotherapy, by 6.4 mm Hg, compared with placebo (reduction of 2.3 mm Hg). The response rate with losartan/ HCTZ was 62.7%, with reductions in SiSBP and SiDBP of 16.8 mm Hg and 10.8 mm Hg, respectively (P < or = 0.01 vs placebo and losartan monotherapy). The incidence of clinical adverse events was comparable in the 3 treatment groups.

CONCLUSIONS

The results of this study suggest that in African American patients, losartan monotherapy was significantly more effective than placebo in lowering SiSBP and SiDBP. Moreover, the losartan/ HCTZ combination regimen resulted in significant and clinically meaningful additional reductions in SiSBP and SiDBP compared with losartan monotherapy or placebo. Losartan monotherapy and the losartan/HCTZ regimens were generally as well tolerated as placebo.

Improving access to mammograms through community-based influenza clinics. A quasi-experimental study

BACKGROUND

It is a national priority to increase breast-cancer screening among women aged > or = 50. Annual influenza clinics may represent an efficient setting in which to promote breast-cancer screening among older women. To our knowledge, this possibility has not previously been explored.

OBJECTIVE

To examine whether offering women attending community-based influenza clinics the opportunity to receive a scheduling telephone call from a mammography facility will result in an increase in the number of mammograms performed over a 6-month period.

METHODS

We used a quasi-experimental design with 6-month follow-up. A contemporaneous population-based survey provided a further control group for comparison. The sample group consisted of a total of 284 women attending nine community-based influenza clinics in a semirural county in Connecticut. All women were aged > or = 50 and reported no mammogram in the preceding 12 months. All women received informational literature on mammography. Experimental subjects were each asked if a radiology facility chosen by the subject could call her at home to schedule a mammogram. Mammograms performed were determined by hospital record for participants who received a scheduling call from a radiology facility, and by self-report for all other participants.

RESULTS

Mammography use following access through influenza clinics was approximately twice that of women attending influenza clinics where access to mammography was not offered. Using three different assumptions regarding participants whose mammography status was unknown, the relative risks ranged between 1.6 and 2.1. For each assumption the results were statistically significant (chi(2)=8.51-12.2; p<0.001).

CONCLUSIONS

Linking access to mammography at community-based influenza clinics can significantly increase the use of mammograms among women aged > or = 50. Further studies should seek to confirm these findings and determine the degree to which they can be replicated in a variety of communities. Enhancing preventive health practice through the bundling of services suggests a new strategy to exploit available interventions to improve health.

Uric acid in hypertension and cardiovascular disease

Cardiovascular disease, and particularly coronary artery disease, remains the leading cause of mortality worldwide, despite recent substantial declines. Hypertension, long recognized as a risk factor for both stroke and myocardial infarction, is an important target for preventive intervention. However, effective hypotensive therapy produces incomplete cardioprotection, and most events that would have occurred in the natural state continue to occur among controlled hypertensive patients. Further progress in reducing the burden of cardiac disease will depend on early identification of risk in successfully treated hypertensive subjects and the development of preventive interventions that go beyond simple reduction of blood pressure. Recently, elevation of uric acid has been found to be associated with subsequent morbidity and mortality in the general population among patients with congestive heart failure, diabetes and hypertension. A prospective study in a large cohort of well controlled hypertensive subjects has revealed a strong, specific, stepwise, independent association of increasing serum uric acid and cardiac morbidity and mortality. Unanswered, however, is the question of whether uric acid is simply an associated phenomenon, or actually contributes to the occurrence of cardiac events.

Urinary sodium excretion and myocardial infarction in hypertensive patients: a prospective cohort study

Reduced-sodium diets are frequently recommended for hypertensive patients. To determine the relation of sodium intake to subsequent cardiovascular disease, 24-h urinary excretion of sodium, potassium, and creatinine and plasma renin activity (PRA) were measured in 2937 mildly and moderately hypertensive patients unmedicated for > or = 3-4 wk. Morbidity and mortality in these treated subjects were ascertained. Subjects were stratified by sex-specific quartiles of urinary sodium excretion; race, cardiovascular status, and blood pressure before and during treatment were similar for each stratum. Patients with lower urinary sodium excretion were thinner, excreted less potassium, and had higher PRA. During an average 3.8-y follow-up, 55 myocardial infarctions (MIs) occurred. Incidence of MIs and urinary sodium excretion were inversely associated in the total population and in males but not in females. In males, age- and race-adjusted MI incidence in the lowest compared with the highest quartile of urinary sodium excretion was 11.5 compared with 2.5 (RR: 4.3; 95% CI: 1.7, 10.6). No association was observed between mortality from causes other than cardiovascular disease (n = 11) and urinary sodium excretion. There was a significant linear trend in proportions of MI by quartile of urinary sodium excretion, with a breakpoint after the lowest quartile. In Cox multivariate analysis, the logarithm of PRA, age, systolic blood pressure, and cholesterol as continuous variables, as well as left ventricular hypertrophy and smoking, had a direct association and urinary sodium excretion an inverse, independent association (P = 0.036) with incidence of MI.

Novel delivery system for verapamil designed to achieve maximal blood pressure control during the early morning

Because the risk of cardiovascular events appears to be greatest in the early morning, this period is a time during which adequate blood pressure (BP) control appears to be most desirable. In this study, a controlled-onset extended-release system (COER-24) that delivers verapamil in a manner designed to achieve maximal levels of drug during the early morning surge in BP was compared with placebo. Ninety-five patients with mild to moderate hypertension were studied. Of this group, 49 patients (mean age 57.6 +/- 1.4 years; 35 men and 14 women) were randomized to take verapamil COER-24 240 mg at 10 PM, and 46 subjects (mean age 55.8 +/- 1.5 years; 29 men and 17 women) were randomized to take placebo. Ambulatory BP monitoring was performed after a 4-week initial placebo period and was repeated after 4 weeks of treatment with verapamil or placebo. Verapamil COER-24 resulted in significant (p < 0.001) decreases in mean whole-day systolic and diastolic BP (-8.2/-6.3 mm Hg; baseline 152/93.0 mm Hg) when compared with placebo (+0.3/-0.9 mm Hg; baseline 150.3/93.2 mm Hg). From 6 AM to noon, verapamil COER-24 resulted in a change in systolic and diastolic BP of -11.6/-9.0 mm Hg, which was significantly (p < 0.001) greater than the change that occurred with placebo (-0.5/-1.0 mm Hg) during the same period. In the last 4 hours of the dosing interval (6 PM to 10 PM), verapamil COER-24 caused significantly greater (p < 0.001) decreases in BP (-7.4/-4.8 mm Hg) than did placebo (+2.7/+1.0 mm Hg). These data demonstrate that the COER-24 system, when administered in the late evening, achieves maximal BP reduction during the early morning hours. Moreover, BP reductions were sustained throughout the 24-hour period.

The relationship between 'job strain,' workplace diastolic blood pressure, and left ventricular mass index. Results of a case-control study

To determine whether "job strain" (defined as high psychological demands and low decision latitude on the job) is associated with increased workplace diastolic blood pressure and the left ventricular mass index, we conducted a case-control study at seven urban work sites of 215 employed men aged 30 to 60 years without evidence of coronary heart disease. After comprehensive blood pressure screening of male employees (N = 2556) at the work site, 87 cases of hypertension and a random sample of 128 controls were studied. In a multiple logistic regression model, job strain was significantly related to hypertension, with an estimated odds ratio of 3.1, after adjusting for age, race, body-mass index, type A behavior, alcohol intake, smoking, work site, 24-hour urine sodium excretion, education, and physical demand level of the job. Controlling for the above variables in subjects aged 30 to 40 years with job strain, we found that the echocardiographically determined left ventricular mass index was, on average, 10.8 g/m2 greater than in subjects without job strain. We conclude that job strain may be a risk factor for both hypertension and structural changes of the heart in working men.

The coming of age in nursing care of the elderly

Worldwide trends and developments point the way toward a restructuring of health care delivery systems to meet increased demands from the elderly and disabled. As nursing, by virtue of its unique position, can play a major role in gerontological care, below the authors present three models that optimize nursing care to ensure effective and efficient service.

A longitudinal study of urinary creatinine and creatinine clearance in normal subjects. Race, sex, and age differences

The purpose of this study was to examine the variability of 24-hour urinary and serum creatinine levels and creatinine clearance in normal subjects and to develop nomograms for assessing the adequacy of 24-hour urine collections. The data were from a longitudinal research program examining biochemical, hormonal, and hemodynamic parameters in normal subjects. Bloods and 24-hour urine specimens were collected at yearly intervals from 144 people over 9 years, and from an additional 110 over 4 years. The subjects were originally distributed equally by sex, race (black, white), blood pressure (three groups within the normal range), and age (three groups). Men had 33% higher urine creatinines per weight than females (P less than 0.001). Because they only had 8% higher creatinine clearance per weight they also exhibited 21% higher serum creatinine. Blacks had 5% higher urine creatinine per weight than whites, perhaps reflecting greater muscle mass, but their serum creatinines were not different from those of whites, reflecting a 5% higher creatinine clearance by weight than whites (P less than 0.01). Interestingly, older black men (age greater than 60 years) had 12% lower urine creatinine/weight than younger black men (P less than 0.001). They also had 13% lower creatinine clearance by weight, resulting in no net difference in serum creatinine. The intraindividual variability in urine creatinine excretion averaged 15% and did not differ between blacks and whites and men and women. The within individual variability in serum creatinine and creatinine clearance averaged 14 and 20%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Renin relationship to sex, race and age in a normotensive population

The relationship of renin activity to sex, race (black or white) and age (less than 50 or greater than or equal to 50 years of age) was examined in 236 normal subjects measure yearly for up to 9 years. There were 58 white women (34 less than 50 years, 24 greater than or equal 50 years), 66 white men (30 less than 50 years, 36 greater than or equal to 50 years), 57 black women (34 less than 50 years, 23 greater than or equal to 50 years) and 55 black men (34 less than 50 years, 21 greater than or equal to 50 years). The results showed men had higher mean renin activities than women, whites had higher activities than blacks and those of under 50 years had higher activities than those of over 50 years. However, the sex and race differences primarily occurred as a consequence of a lack of decline in renin activity with age among white men. The relationship with age as a continuous variable was weak (r = -0.21) and no relationship with age was found in 22 subjects with a least 7 years of data. No significant differences in urinary sodium excretion were observed between the groups. These results suggest that renin activity tends to be lower in older subjects and that differences in renin activity related to sex and race, while statistically significant, may not be physiologically important.

Intermittent claudication: a double-blind crossover trial of pentoxifylline

The influence of the xanthine derivative pentoxifylline ('Trental' or BL191; Hoechst-Roussel) on exercise tolerance was measured in 38 subjects with stable, severe to moderately severe, intermittent claudication who completed a randomised, double-blind, placebo controlled, cross-over clinical trial. Patients received placebo tablets or 400 mg slow-release pentoxifylline tablets ('Trental 400') twice a day for one week, followed by three times daily for seven weeks, and then crossed over to receive the alternate preparation for another eight weeks. Claudication distance and walking distance were measured on a treadmill before starting treatment and again at four-week intervals during the trial. At the same times, red blood cell filterability, plasma fibrinogen concentration and blood viscosity, resting and post-ischemic calf muscle blood flow, and the resting and post-exercise ankle/brachial systolic pressure ratio were also measured. In this study, the observed effects of pentoxifylline treatment were no greater than those of placebo, even though serum levels of pentoxifylline and its hydroxy-metabolite were within the anticipated range. This was shown by a 'therapeutic effect ratio' of 0.98 for treadmill claudication distance and 0.96 for treadmill walking distance after within-patient analysis at the end of the cross-over (where a ratio of 1.0 means the test drug and placebo effects are identical). These ratios have 95% confidence limits of 0.72-1.34 and 0.74-1.25, respectively.

Absenteeism and labelling in hypertensive subjects. Prevention of an adverse impact in those at high risk

In this work-site population, the illness absenteeism of 259 hypertensive subjects was studied in the year after they were screened and labelled. Absenteeism due to illness increased more in 48 patients who were unaware of their hypertension (newly labelled) than in the 211 subjects who were aware. Among the newly labelled subjects, only the young subjects and those with "pure" systolic hypertension experienced increased absenteeism; the older subjects with diastolic hypertension did not. The newly labelled subjects who received active follow-up and treatment with antihypertensive medication had only minimal increases in absenteeism. In contrast, those who received active follow-up without medication, and those who received only episodic follow-up had significantly greater increases. Vigorous efforts are warranted to insure active follow-up and treatment for hypertensive subjects after their condition has been labelled. Caution should be exercised in labelling, however, if no antihypertensive treatment is initiated.

Plasma prorenin: cryoactivation and relationship to renin substrate in normal subjects

We previously demonstrated an inactive form of renin, termed prorenin, in the plasma of normal, hypertensive and anephric patients. Prorenin activity can be determined in plasma from the total renin activity after activation, minus the prior endogenous plasma renin activity. In the present study, conditions for cryoactivation of prorenin have been defined. Plasma prorenin is slowly converted to active renin-like material at -5 degrees C at pH 7.4. Activation takes four days and does not occur at pH 5.0. The degree of activation increases above pH 5 and is greatest between pH 7 and pH 9. Thus, almost no cryoactivation of prorenin occurs at the pH optimum for renin (5.7) in contrast to maximum activation at pH 7.4. No activation has been observed in the frozen state, but it does occur with decreasing rapidity at temperatures from -5 degress to +4 degress C. Since blood samples obtained for the determination of plasma renin activity are routinely chilled upon collection by most laboratories, some activatin of prorenin most likely occurs in all routine renin assays. The pH optimum of the enzymatic reaction of the activated prorenin in plasma is 5.8, the same as for renal renin, and the shape of the pH optimum curve is similar to that of renal renin added to human plasma. In a group of 23 normal subjects with plasma renin activity of 3.5 +/- 2.9 (SD), the activated prorenin increment was found to be significantly higher, 6.3 +/- 5.0 (SD) ng/ml/hour. Unlike plasma renin activity, prorenin activity in these normal subjects was directly related to the concentration of renin substrate (p less than 0.001). When the actual "concentration" of prorenin was calculated using renal renin as the reference standard, a direct relationship was also found between the concentration of prorenin and renin substrate (p less than 0.01). The observed relationship between prorenin and renin substrate concentrations might be a consequence of their regulation by common factors.