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At least 577 records · Page 32Linked to original sources
PubMed2002

Prognostic significance of the nocturnal decline in blood pressure in individuals with and without high 24-h blood pressure: the Ohasama study.

OBJECTIVE: To examine the relationship between the normal nocturnal decline in blood pressure and the risk of cardiovascular mortality in individuals with and without high 24-h blood pressure values. METHODS: We obtained 24-h ambulatory blood pressure readings from 1542 residents of Ohasama, Japan, who were aged 40 years or more and were representative of the Japanese general population. We then followed up their survival for a mean of 9.2 years. The relationship was analysed using a Cox proportional hazards model adjusted for possible confounding factors. RESULTS: There was a linear relationship between the nocturnal decline in blood pressure and cardiovascular mortality. On average, each 5% decrease in the decline in nocturnal systolic/diastolic blood pressure was associated with an approximately 20% greater risk of cardiovascular mortality. There were no significant interactions for the risk between 24-h systolic/diastolic blood pressure values and continuous values for the nocturnal decline in blood pressure ( for interaction 0.6). Even when 24-h blood pressure values were within the normal range ( 135/80 mmHg, average 118/69 mmHg), diminished nocturnal decreases in systolic/diastolic blood pressure were associated with an increased risk of cardiovascular mortality. CONCLUSIONS: This is the first study to demonstrate that a diminished nocturnal decline in blood pressure is a risk factor for cardiovascular mortality, independent of the overall blood pressure load during a 24-h period, in the general population.

Aged↗
PubMed2001

Reference values for ambulatory blood pressure and self-measured blood pressure based on prospective outcome data.

Although self-measured blood pressure and ambulatory blood pressure are widely used for research and clinical purposes, reference values are still scarcely supported by prospective outcome data. For self-measured blood pressure, values of 135 mmHg systolic and 85 mmHg diastolic (an average of two measurements in the morning and an additional two in the evening for at least 3 working days) have been suggested as the upper-normal reference limits. Unfortunately, these values have received limited support because only one study, the Ohasama study, examined the prognostic value of self-measured home blood pressure. For non-invasive 24 h ambulatory blood pressure, there are at least 11 reports of prospective outcome studies from independent centres that have examined the prognostic values of ambulatory blood pressure, but not all have attempted to define reference values. Currently, an average daytime blood pressure of less that 135 mmHg systolic and less than 85 mmHg diastolic is generally considered to be normal, and a level below 130/80 mmHg may be considered optimal. A reduction in blood pressure of less than 10% from day to night identifies subjects with an increased cardiovascular risk. There is some evidence that cardiovascular risk is further increased when night-time blood pressure is higher than daytime blood pressure. An average 24 h pulse pressure of over 53 mmHg identifies subjects with a raised cardiovascular risk.

Blood Pressure Determination↗
PubMed2003

Finometer, finger pressure measurements with the possibility to reconstruct brachial pressure.

OBJECTIVE: To evaluate three methods aimed at the reconstruction of brachial pressure from non-invasive finger arterial pressure measurements as implemented in the Finometer trade mark, (FMS, Finapres Measurement Systems, Arnhem, Netherlands), the successor to the Finapres trade mark (TNO Biomedical Instrumentation, Amsterdam, Netherlands). METHODS: Finger arterial pressure (FinAP) may differ from intra-brachial pressure (BAP). Pulse shape differences are removed by applying a generalized waveform filter. Pressure level differences are corrected by a generalized level correction equation using filtered systolic and diastolic levels and by level calibration, which uses an additional return-to-flow (RTF) systolic pressure measurement on the ipsilateral upper arm for an individual calibration of the reconstructed brachial pressure. VALIDATION: These methods were validated in 37 subjects, aged 41 to 83 years after a cardiac catheterization procedure. Intra-brachial and Finometer pressures were recorded simultaneously. Finometer pressures were compared after application of waveform filtering and level correction (flcAP), and after an additional RTF calibration (reBAP). RESULTS: Finger arterial systolic, diastolic and mean pressures for the group differed from BAP by -9.7 +/- 13.0, -11.6 +/- 8.0 and -16.3 +/- 7.9 mmHg (mean +/- SD) respectively. Similarly flcAP differed by -1.1 +/- 10.7, -0.2 +/- 6.8 and -1.5 +/- 6.6 mmHg and reBAP differed by 3.1 +/- 7.6, 4.0 +/- 5.6 and 2.7 +/- 4.7 mmHg. CONCLUSION: Reconstruction of BAP from FinAP as implemented in the Finometer reduces the pressure differences, with an individual RTF calibration to well within AAMI requirements.

Adult↗
PubMed2006

Blood pressure in acute ischemic stroke and mortality: a study with noninvasive blood pressure monitoring.

BACKGROUND: In acute ischemic stroke, a transient elevation of blood pressure is common; its significance and its relationship with the neurological outcome are still unclear. METHODS: In 71 consecutive patients with acute ischemic stroke, aged 25-94 years, admitted to our unit, we investigated the relationships between the blood pressure variation during the first 24 h and mortality at 3 months (study endpoint). Neurological status was assessed with the National Institutes of Health Stroke Scale. Blood pressure was measured with bedside noninvasive blood pressure monitoring every 15 min. The mean of four measurements at the emergency department and the mean of 12 measures (during a 3-h interval) at 12 and at 24 h after stroke onset were considered for analysis. Antihypertensive treatment was given in accordance with the Recommendations for Stroke Management of European Stroke Initiative. RESULTS: In the whole series, 21% were atherothrombotic, 32% cardioembolic, 34% lacunar, and 13% of unknown or other cause. Blood pressure was 160+ or -3/86+ or -2 mmHg at the emergency department, 148+ or -3/82+ or -2 mmHg at 12 h, and 147+ or -3/81+ or -2 mmHg at 24 h (P<0.05). Four patients (11%) of those in whom mean blood pressure decreased >5 mmHg, and 12 (33%) of the others, in whom mean blood pressure decreased < or =5 mmHg or did not decrease, reached the endpoint (P<0.05). According to the multivariate Cox model, NIHSS score at the emergency department (95% confidence interval: 1.025-1.238, P=0.013) and age (95% confidence interval: 1.007-1.259, P=0.038) were predictors of reaching the endpoint, whereas mean blood pressure reduction 24 h after stroke onset had a protective effect (95% confidence interval: 0.845-0.995, P=0.038). Diabetes, mean blood pressure at the emergency department and the need for antihypertensive therapy did not correlate with the outcome. CONCLUSIONS: Noninvasive blood pressure monitoring during the first 24 h of acute ischemic stroke may be useful in the prognostic stratification by showing moderate blood pressure decrease, either spontaneous or drug induced, which is associated with a favorable prognosis at 3 months.

Adult↗
PubMed2006

Daytime ambulatory systolic blood pressure is more effective at predicting mortality than clinic blood pressure.

OBJECTIVES: To assess the prognostic value of daytime ambulatory blood pressure compared with routine clinic blood pressure in determining mortality. METHODS: Prospective multicentre study in 48 general practices in Oxfordshire, a hypertension clinic in Oxford and a hypertension clinic in London. RESULTS: A cohort of 10 129 patients from Oxford and London was followed up for a median of 8.2 years. Nine hundred and one deaths were recorded (8.9%) corresponding to a mortality rate per 1000 years of follow-up of 10.8 (99% confidence interval 9.9-11.8). Comparing the highest quartile for systolic ambulatory blood pressure with the lowest (>or=160 vs. <135 mmHg) gives an estimated age sex-adjusted hazard ratio for mortality of 1.51 (95% confidence interval 1.25-1.83, P<0.001). The corresponding comparison for clinic systolic blood pressure (>or=174 vs. <148 mmHg) results in a hazard ratio of 1.02 (95% confidence interval 0.84-1.24, P=0.9). Comparing ambulatory versus clinic systolic blood pressure (10 mmHg groupings) using nested statistical modelling, removal of the ambulatory blood pressure term from the baseline Cox model (nine 10 mmHg categories) resulted in a highly significant likelihood ratio test statistic of 52.5 (df=8, P<0.0001). The corresponding result for removal of the clinic blood pressure term was 18.1 (df=8, P=0.02), thus reinforcing the finding that ambulatory blood pressure monitoring has greater prognostic significance. Ambulatory blood pressure was also a better predictor of all-cause mortality both in patients taking medication and those not taking medication at the time of monitoring. CONCLUSION: Daytime ambulatory blood pressure monitoring is a much better prognostic indicator of all-cause mortality than clinic blood pressure.

Adolescent↗
PubMed1980

Effects of hypercapnia and arterial hypotension and hypertension on cerebrospinal fluid pulse pressure and intracranial volume-pressure relationships.

In twelve anaesthetised, ventilated dogs the effects of hypercapnia and pharmacologically induced arterial hypotension and hypertension on the interrelation between volume-pressure response (VPR) and cerebro-spinal fluid (CSF) pulse pressure were studied during continuous inflation of a supratentorial extradural balloon. Hypercapnia did not significantly affect the intracranial volume-pressure relationships, but did cause a significant increase in gradient of the relationship between CSF pulse pressure and intracranial pressure (ICP). Alteration of the arterial blood pressure showed opposite effects on VPR and CSF pulse pressure. A decrease in VPR and an increase in pulse pressure were observed during arterial hypotension; the reverse was found during arterial hypertension. The discrepancy between the effects on VPR and CSF pulse pressure of the variables under study was explained by changes in the transient increase in cerebral blood volume per cardiac cycle. On the basis of the results of this study it will be possible, during clinical ICP monitoring, to interpret changes in the CSF pulse pressure to ICP ratio in terms of changes in intracranial volume-pressure relationships.

Animals↗
PubMed1995

Alteration of testicular microvascular pressures during venous pressure elevation.

We have addressed the hypothesis that varicocele-related infertility is caused in part by a pressure-induced disturbance of testicular convective transport that upsets the testicular hormonal environment and thus impairs spermatogenesis. The left testis of the hamster [pentobarbital sodium (Nembutal), 70 mg/kg ip] was prepared for microcirculatory observations. Testicular venous pressure was acutely elevated by ligating collateral routes of venous outflow and partially occluding, via a snare, the main venous outflow distal to the pampiniform plexus. Simultaneous direct pressure measurements (servo-null method) were made to monitor venous pressure elevation and quantify resulting pressure and diameter changes in the arterial feed to the testis and in postcapillary venules. The data show that over 90% of the venous pressure elevation (VPE) was transmitted to the postcapillary venules. VPE affected intravascular pressures throughout the testis microvasculature; on average, capsular artery pressure increased by 83% of the VPE, although part of this increase was due to a rise in systemic arterial pressure. Vasoconstriction helped to buffer the pressure rise in the capsular artery, probably at the expense of flow amplitude. Yet the vasoconstriction was ineffective in preventing a rise in exchange vessel pressure. These data suggest that microvascular fluid exchange may be dramatically altered in varicocele, upsetting the hormonal and paracrine environment of the testis, and hence, impairing physiological regulation of gametogenesis.

Animals↗
PubMed1997

Effects of transient intrathoracic pressure changes (hiccups) on systemic arterial pressure.

The purpose of the study was to determine the effect of transient changes in intrathoracic pressure on systemic arterial pressure by utilizing hiccups as a tool. Values of systolic and diastolic pressures before, during, and after hiccups were determined in 10 intubated preterm infants. Early-systolic hiccups decreased systolic blood pressure significantly (P < 0.05) compared with control (39.38 +/- 2.72 vs. 46.46 +/- 3.41 mmHg) and posthiccups values, whereas no significant change in systolic blood pressure occurred during late-systolic hiccups. Diastolic pressure immediately after the hiccups remained unchanged during both early- and late-systolic hiccups. In contrast, diastolic pressure decreased significantly (P < 0.05) when hiccups occurred during diastole (both early and late). Systolic pressures of the succeeding cardiac cycle remained unchanged after early-diastolic hiccups, whereas they decreased after late-diastolic hiccups. These results indicate that transient decreases in intrathoracic pressure reduce systemic arterial pressure primarily through an increase in the volume of the thoracic aorta. A reduction in stroke volume appears to contribute to the reduction in systolic pressure.

Blood Pressure↗
PubMed1992

Evaluation of noninvasive blood pressure monitoring devices Spacelabs 90202 and 90207 versus resting and ambulatory 24-hour intra-arterial blood pressure.

This study evaluated the accuracy of blood pressure values provided by the Spacelabs 90202 and 90207 devices in comparison with intra-arterial recording in 19 subjects at rest and in nine subjects in ambulatory conditions (Oxford method). At rest Spacelabs monitors reflected intra-arterial systolic blood pressure values very closely but overestimated to a considerable extent intra-arterial diastolic blood pressure (Spacelabs-intra-arterial differences, -0.8 +/- 9.2, NS, and 9.1 +/- 8.8 mm Hg, p less than 0.01, for systolic and diastolic blood pressures, respectively). In ambulatory conditions Spacelabs-intra-arterial average differences in 24-hour values were +0.4 +/- 5.1 mm Hg for systolic blood pressure (NS) and +14.0 +/- 2.9 mm Hg for diastolic blood pressure (p less than 0.01) when group data were considered. The performance of both Spacelabs devices was worse when assessed in individual subjects or for each hourly interval. In spite of these differences between noninvasive and intra-arterial absolute blood pressure values, however, Spacelabs 90202 and 90207 monitors were able to faithfully reflect directional hour-to-hour changes in intra-arterial blood pressure (chi 2 = 18.2 and chi 2 = 23.1 for systolic and diastolic blood pressures, respectively, p less than 0.01). No differences were found between the performance of the two Spacelabs devices. Thus, although the absolute accuracy of blood pressure values provided by these monitors in ambulatory subjects is still limited, they seem to be suitable for studies aimed at assessing 24-hour blood pressure profiles quantitatively as well as qualitatively.

Adolescent↗
PubMed1993

Effects of positive end-expiratory pressure and body position on pressure in the thoracic great veins.

Positive end-expiratory pressure (PEEP) commonly decreases cardiac output. The major cause of this is believed to be decreased venous return due to increased right atrial pressure. We hypothesized that when the lungs were hyperinflated they could also restrict venous return by directly compressing the thoracic vena cavae. We measured the longitudinal distribution of pressure in the thoracic vena cavae of 10 dogs on and off 10 mm Hg PEEP, in the supine (S), prone (P), right lateral (RL), and left lateral decubitus (LL) positions. In the superior vena cava (SVC) both on and off PEEP, and in the inferior vena cava (IVC) off PEEP, pressure fell uniformly from the thoracic inlet to the right atrium. However, in the IVC on PEEP, intravascular pressure fell abruptly by up to 5 mm Hg. This pressure drop occurred in a discrete (1 to 2-cm) segment of the IVC, suggesting a localized increased in extravascular surface pressure. When this pressure inflection was present, changes in right atrial pressure had no effect on pressure in the IVC upstream of the inflection, consistent with a "vascular waterfall." These observations were most prominent in the LL, least common in the RL, and variably present in the P and S positions. Occlusion of the right bronchus intermedius prior to PEEP (preventing right lower, middle, and accessory lobe inflation) prevented the appearance of the pressure inflection during PEEP in the LL but not in the S or P positions. We conclude that PEEP impedes venous return partly by direct compression of the IVC, predominantly in positions in which the IVC is non-dependent.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1971

Effective glomerular filtration pressure and single nephron filtration rate during hydropenia, elevated ureteral pressure, and acute volume expansion with isotonic saline.

Free-flow and stop-flow intratubular pressures were measured in rats with an improved Gertz technique using Landis micropipets or a Kulite microtransducer. In hydropenia, average single nephron glomerular filtration rate was 29.3 nl/min, glomerular hydrostatic pressure (stop-flow pressure + plasma colloid osmotic pressure) was 70 cm H(2)O and mean glomerular effective filtration pressure was 12.7-14.3 cm H(2)O, approaching zero at the efferent end of the glomerulus. Thus, the glomerulus is extremely permeable, having a filtration coefficient four to five times greater than previously estimated. Mean effective filtration pressure and single nephron glomerular filtartion rate fell with elevated ureteral pressure and rose with volume expansion, more or less proportionately. Changes in effective filtration pressure were due primarily to increased intratubular pressure in ureteral obstruction and to reduced plasma colloid osmotic pressure in volume expansion; glomerular hydrostatic pressure remained constant in both conditions and thus played no role in regulation of filtration rate.

Animals↗
PubMed2004

Relationship between blood pressure measurements recorded on patients' charts in family physicians' offices and subsequent 24 hour ambulatory blood pressure monitoring.

BACKGROUND: In most western countries 20% of adults have hypertension. Reports in the literature suggest that from 31 to 86% of treated patients are not at recommended target levels. However it is important to consider how we are determining whether targets are unmet and the degree to which they are unmet. Our underlying hypothesis is that white coat effect is partially responsible for the reported low rates of control of hypertension by primary care practitioners. METHODS: The study population consists of 1142 patients who are being assessed for enrollment in two community-based randomized controlled trials. Patients must have essential hypertension, be on antihypertensive medication, and must not have met their blood pressure targets. We are reporting on the proportion of patients who have not achieved target, and the degree to which they have not achieved their target. We also report on the mean daytime blood pressures on 24 hour ABPM and compare these to mean blood pressures found on the patients' charts. RESULTS: We identified 3284 patient charts of patients with hypertension. Of these, 1142 were determined to be "out of control" (did not achieve target) and 436 agreed to undergo 24 hour ABPM for final determination of eligibility. Overwhelmingly (95.8% of the time) it was the systolic blood pressure that was not under control. However, most of the patients who had not achieved target according to our criteria were within 10 mmHg of the recommended targets. Isolated systolic blood pressure was the best predictor of elevated mean daytime blood pressure on 24 hour ABPM. CONCLUSIONS: At least 35% of patients had not achieved target blood pressure levels and this is primarily due to lack of control of systolic blood pressure. The best predictor of continuing hypertension on 24 hour ABPM was the mean systolic blood pressure on the patients chart. However, only 69% of patients who were uncontrolled according blood pressures recorded in the chart were uncontrolled according to 24 hour ABPM criteria. This suggests that the white coat effect makes blood pressure measurements in the doctor's offices, at least as currently done, not sufficiently accurate for determining treatment endpoint.

Adult↗
PubMed2000

Nasal continuous positive airway pressure devices do not maintain the set pressure dynamically when tested under simulated clinical conditions.

STUDY OBJECTIVES: Nasal continuous positive airway pressure (CPAP) is standard therapy for obstructive sleep apnea syndrome. The effective nasal mask pressure may be adversely affected by factors that increase system resistance (eg, long tubing and/or water condensation) and by dynamic variables (breathing frequency [f] and tidal volume [VT]). The present study was conducted in order to assess the performance of CPAP machines throughout a range of simulated clinical conditions. DESIGN: Four currently used CPAP machines were tested at settings of 5, 10, 15, and 20 cm H(2)O using a pulmonary waveform generator to produce VTs of 0.4, 0.8, and 1.2 L at frequencies of 10, 20, and 30 breaths/min. Machines were tested under five conditions: 6-foot and 12-foot tubing, with and without an in-line humidifier, and 12-foot tubing with humidifier and water condensation. MEASUREMENTS: Maximum and minimum mask pressure measurements were obtained during five respiratory cycles for each dynamic variable under each of the five conditions and CPAP settings (180 experiments on each of four CPAP models). RESULTS: Using typical clinical parameters (VT, 0.4 L and 0.8 L; f, 10 breaths/min and 20 breaths/min; and CPAP, 5 to 15 cm H(2)O), mask pressure consistently varied above and below the set point when additional tubing and/or a humidifier were added to the system (0.7 to 2.9 cm H(2)O below and 0.5 to 1.0 cm H(2)O above the set pressure). Water condensation caused large pressure deviations (inspiratory pressure ranged from 3.5 to 5.6 cm H(2)O below set pressure, and expiratory pressure ranged from 0.7 to 3.5 cm H(2)O above set pressure). CONCLUSIONS: Therapy and compliance could be adversely affected because some CPAP machines in current use do not maintain constant continuous mask pressure when tested using simulated conditions, especially when water condenses in the tubing.

Equipment Design↗
PubMed1977

Multidisciplinary treatment of chronic pulmonary insufficiency. 4. The influence of intrathoracic pressure variations on increases in pulmonary vascular pressure during exercise in patients with chronic obstructive pulmonary disease.

In the present era of direct monitoring of pressure in patients with chronic obstructive pulmonary disease (COPD), an appreciation of all factors that may influence the observed pulmonary vascular pressures is essential. Our study examines the impact of respiratory variations in intrathoracic pressure on the recorded pulmonary vascular pressures in 28 patients with COPD. Althouth pulmonary hypertension was present in only nine subjects at rest, all had an abnormal increase in the mean pulmonary arterial pressure during supine exercise. In 15 subjects, this abnormal response was, in part, related to an increase in pulmonary arterial wedge pressure to 15 mm Hg or more. The increase in pulmonary arterial wedge pressure was directly related to the amplitude of the peak-to-peak respiratory variation of such wedge pressure. This variation correlated with the specific airway resistance but was not related to the arterial oxygen pressure or pulmonary vascular resistance. These findings indicate the important influence of exaggerated respiratory effort on the measurement of pulmonary arterial wedge pressure and mean pulmonary arterial pressure in patients with chronic obstructive pulmonary disease.

Airway Obstruction↗
PubMed2004

Comparison of total body tissue interface pressure of specialized pressure-relieving mattresses.

OBJECTIVE: The pressure-relieving ability of three specialized support surface mattresses was investigated and compared to a standard hospital mattress by measuring total body tissue interface pressure in a laboratory experiment designed to simulate clinical conditions predisposing to formation of pressure ulcers. SUMMARY BACKGROUND DATA: Pressure ulcers are commonly seen in the elderly; in patients with trauma, burns, spinal cord injury, neurological deficits, peripheral vascular disease, and stroke; and in other patient groups with debilitating or emaciating illness. They represent from 4 to 29% of all hospital admissions. This study was undertaken to compare three different types of specialty beds to a standard hospital mattress in order to find a mattress that prevents the occurrence of pressure ulcers. METHODS: The tested beds and mattresses were the Orthoderm Convertible II (Bio-Clinic Inc., Ontario, Canada) low air-loss mattress on a Stryker PMS (Stryker Inc., Kalamazoo, Michigan, USA) bed; the FluidAir Elite (KCI Inc., San Antonio, Texas, USA) air-fluidized bed; the Pegasus Airwave mattress (Pegasus Airwave Inc., Boca Raton, Florida, USA) on a Stryker PMS bed; and a standard hospital mattress on a Stryker PMS bed. The nineteen test subjects were all healthy with exclusion criteria of spinal cord injury, immobility, or other neurological or physical impairment. The Force Management System (Numotech Inc., Northridge, California, USA) was used to measure tissue interface pressure. RESULTS: The study data show that the Pegasus Airwave mattress total surface pressure values of the anatomical regions (total body, torso, hips) of the body are lower than those of the other three tested mattresses. The total body and hip pressure resulting from pressure maturation is significantly less on the Pegasus Airwave mattress than on to the hospital bed, the air-fluidized bed, and the low air-loss bed. CONCLUSIONS: The Pegasus Airwave mattress outperforms the other tested support surfaces by decreasing overall pressure. Therefore, the Pegasus Airwave mattress is an excellent addition to augment nursing care in the prevention and treatment of pressure sores.

Beds↗
PubMed1986

Cerebral perfusion pressure, intracranial pressure, and head elevation.

Previous investigations have suggested that intracranial pressure waves may be induced by reduction of cerebral perfusion pressure (CPP). Since pressure waves were noted to be more common in patients with their head elevated at a standard 20 degrees to 30 degrees, CPP was studied as a function of head position and its effect upon intracranial pressure (ICP). In 18 patients with varying degrees of intracranial hypertension, systemic arterial blood pressure (SABP) was monitored at the level of both the head and the heart. Intracranial pressure and central venous pressure were assessed at every 10 degrees of head elevation from 0 degree to 50 degrees. For every 10 degrees of head elevation, the average ICP decreased by 1 mm Hg associated with a reduction of 2 to 3 mm Hg CPP. The CPP was not beneficially affected by any degree of head elevation. Maximal CPP (73 +/- 3.4 mm Hg (mean +/- standard error of the mean] always occurred with the head in a horizontal position. Cerebrospinal fluid pressure waves occurred in four of the 18 patients studied as a function of reduced CPP caused by head elevation alone. Thus, elevation of the head of the bed was associated with the development of CPP decrements in all cases, and it precipitated pressure waves in some. In 15 of the 18 patients, CPP was maintained by spontaneous 10- to 20-mm Hg increases in SABP, and pressure waves did not occur if CPP was maintained at 70 to 75 mm Hg or above. It is concluded that 0 degree head elevation maximizes CPP and reduces the severity and frequency of pressure-wave occurrence. If the head of the bed is to be elevated, then adequate hydration and avoidance of pharmacological agents that reduce SABP or prevent its rise are required to maximize CPP.

Blood Pressure↗
PubMed2000

[Experimental study. Reduction of pressure in areas of risk of developing pressure ulcers with a hydrocellular dressing].

INTRODUCTION: The handling of pressure is a basic measure in the prevention and treatment of bed sores. It is possible to reduce and ease pressure by various means including changes in posture, use of special surfaces for handling pressure as well as the use of local applications or external applications which reduce pressure. Today nurses have a large quantity of external applications available to use although only some hydrocellular ones are capable to reduce pressure due to their hydrocellular structure. METHODS AND MATERIALS: An experimental study was designed to calculate the level of pressure before and after applying an Allevyn hydrocellular external application in the area of the sacrum, ischium, and heel of three healthy volunteers; first, Volunteer A, a 85 kg. 170 cm man; second, Volunteer B, a 54.3 kg. 159 cm woman; and third, Volunteer C, a 69.4 kg 164 cm man. Measures were taken on two types of surfaces: a viscoelastic foam mattress and a conventional hospital mattress. All measurements were repeated at 0, 30, 45 and 60 degrees of inclination. Pressure was determined by means of a Talley pressure monitor, Oxford Pressure Monitor MK II. RESULTS: A total of 144 pressure reading were taken. The overall average reduction after applying a external hydrocellular application on all volunteers, at all inclinations and on all surfaces for each of the three zones were 19.5% in the sacrum, 13.8% in the ischium and 20.15% in the heel. COMMENTARY: Even though our study has its limitations, such as young, healthy volunteers, we can establish that the external hydrocellular application studied does have a local reducing effect on pressure. Since every external hydrocellular application has its own specific structure, the results of our study can not be applied with certainty to other external applications inside the hydrocellular group.

Bandages, Hydrocolloid↗
PubMed2001

[Blood pressure variability on the basis of 24-hour ambulatory blood pressure monitoring in a group of healthy persons].

The aim of our research was to test twenty four hour variabilities of blood pressure (BPV) in a group of healty persons. The group consisted of 125 healthy persons (58 men and 67 women) 14-70 years old (mean age 33.8 +/- 14 years). Standard deviation (SD) from average blood pressure and the presence and size of night fall of arterial blood pressure (dippers and non dippers) was tested as parameters of BPLV. Average twenty four hours systolic blood pressure (SBP) in all the group was 119.7 +/- 10.9 mm Hg (123.5 +/- 11.5 mm Hg during the day and 106.2 +/- 12.2 at night). Average twenty-four-hour diastolic blood pressure (DBP) in all group was 71.9 +/- 9.0 mm Hg (74.0 +/- 9.5 during the day, 62.8 +/- 9.3 mm Hg at night). The mean SD of 24-hour SBP was 15.2 +/- 3.5 mm Hg (13.6 +/- for day's hours and 11.2 +/- 4.1 mm Hg at night). The mean SD of 24-hour DBP was 13.0 +/- 2.6 mm Hg (12.1 +/- 2.8 at the day and 9.8 +/- 3.0 at night). There were no correlation between and SBP SD or DBP SD and sex, age of the investigated patients and their membership to dipper and nondipper group. The positive correlation between SBP and and its SD was observed in the group with SBP below 120 mmHg and the same was ascertained in group of people below 40 years of life. Average night fall of SBP was 17.17 +/- 9.42 mm Hg (13.9 +/- 7.4%). Average night fall of DBP was 11.70 +/- 6.91 mmHg (15.7 +/- 8.8%) Nondippers ascertained 28.8% of all group. (32.8% of women and 24.4% of men). Multivariate analysis showed relationship between membership to dipper group and mean diurnal systolic blood pressure (odds ratio 0.93, 95% confidence interval 0.89-0.97, p = 0.02) and between low value of systolic pressure SD during all day monitoring and mean diurnal systolic blood pressure (odds ratio 0.94, 95% confidence interval 0.89-0.99, p = 0.02). Variability of arterial blood pressure is sex, age and mean diurnal pressure related. Parameters of short and long term variability are characterised by large repeatability. Our variability values can be voice in discussion on the norms in analysis of normal blood pressure patients.

Adolescent↗