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At least 415 records · Page 23Linked to original sources
PubMed2006

Use of 24-h ambulatory blood pressure monitoring to assess blood pressure control: a comparison of olmesartan medoxomil and amlodipine besylate.

OBJECTIVE: Olmesartan medoxomil is an angiotensin II receptor blocker with similar antihypertensive efficacy as the calcium channel blocker amlodipine besylate in patients with mild-to-moderate hypertension. In addition to a drug's ability to lower blood pressure, the effectiveness of the agent in enabling patients to achieve specific blood pressure targets is an important clinical consideration. This secondary analysis of a randomized, double-blind study compared the efficacy of olmesartan medoxomil with that of amlodipine besylate in achieving ambulatory blood pressure goals among patients with mild-to-moderate hypertension. METHODS: Following a 4-week placebo run-in, 440 study participants aged >or=18 years were randomized to olmesartan medoxomil (20 mg/day), amlodipine besylate (5 mg/day), or placebo for 8 weeks. The proportion of participants achieving specific systolic and diastolic ambulatory blood pressure goal levels was calculated by dividing the number of participants who had achieved a particular blood pressure goal by the total number of patients in the intent-to-treat population. RESULTS: After 8 weeks of treatment, a mean 24-h ambulatory blood pressure of <130/80 or <130/85 mmHg was achieved by significantly more participants in the olmesartan medoxomil group (18.1 and 30.4%, respectively) than in the amlodipine besylate (7.0 and 14.0%, respectively) or placebo (1.9% for both) groups. The target daytime ambulatory blood pressure of <135/85 mmHg was achieved by more participants in the olmesartan medoxomil group than in the amlodipine besylate group (15.8 vs. 5.8%, respectively; P<0.01). CONCLUSION: In a previous publication of the same study, we demonstrated that starting doses of olmesartan medoxomil and amlodipine besylate produced similar mean reductions in blood pressure. In this subanalysis of the blood pressure data from that primary publication, however, olmesartan medoxomil therapy was shown to result in a greater proportion of patients achieving specific ambulatory blood pressure goals than therapy with amlodipine besylate. As blood pressure goal attainment may be of more direct clinical relevance than numerical blood pressure lowering, the achievement of blood pressure goals should be a key efficacy parameter assessed in clinical trials of antihypertensive medications.

Amlodipine↗
PubMed1993

Effect of airway and left atrial pressures on microvascular and interstitial pressures in adult lungs.

The purpose of this study was to determine the effect of lung inflation and left atrial pressure on the hydrostatic pressure gradient for fluid flux across 20- to 80-microns-diam arterioles and venules in isolated perfused lungs of adult rabbits. We used the micropuncture technique and measured microvascular or interstitial pressures at constant airway pressures of 5 and 15 cmH2O with left atrial pressure adjusted above (zone 3 conditions) or below (zone 2 conditions) airway pressure. Only in lungs inflated to the higher airway pressure did a reduction in left atrial pressure below airway pressure result in concomitant reductions in venular pressure. This suggests that the site of flow limitation in zone 2 shifted from venules > 80 microns diam toward vessels <20 microns diam with inflation from 5 to 15 cmH2O. With the lungs under zone 3 conditions, both transarteriolar and transvenular gradients (microvascular-interstitial pressures) were greater at the higher compared with the lower airway pressure. In contrast, transarteriolar and transvenular gradients changed in opposite directions when compared at the two inflation pressures under zone 2 conditions. Counteracting changes in transmicrovascular gradients make it difficult to predict the effect on fluid filtration from lung inflation under zone 2 conditions. When zone 3 conditions are maintained during inflation, the tendency for edema formation should increase.

Air Pressure↗
PubMed2001

Prospective evaluation of a method for estimating ascending aortic pressure from the radial artery pressure waveform.

Pressure wave reflection in the upper limb causes amplification of the arterial pulse so that radial systolic and pulse pressures are greater than in the ascending aorta. Wave transmission properties in the upper limbs (in contrast to the descending aorta and lower limbs) change little with age, disease, and drug therapy in adult humans. Such consistency has led to use of a generalized transfer function to synthesize the ascending aortic pressure pulse from the radial pulse. Validity of this approach was tested for estimation of aortic systolic, diastolic, pulse, and mean pressures from the radial pressure waveform. Ascending aortic and radial pressure waveforms were recorded simultaneously at cardiac surgery, before initiation of cardiopulmonary bypass, with matched, fluid-filled manometer systems in 62 patients under control conditions and during nitroglycerin infusion. Aortic pressure pulse waves, generated from the radial pulse, showed agreement with the measured aortic pulse waves with respect to systolic, diastolic, pulse, and mean pressures, with mean differences <1 mm Hg. Control differences in Bland-Altman plots for mean+/-SD in mm Hg were systolic, 0.0+/-4.4; diastolic, 0.6+/-1.7; pulse, -0.7+/-4.2; and mean pressure, -0.5+/-2.0. For nitroglycerin infusion, differences respectively were systolic, -0.2+/-4.3; diastolic, 0.6+/-1.7; pulse, -0.8+/-4.1; and mean pressure, -0.4+/-1.8. Differences were within specified limits of the Association for the Advancement of Medical Instrumentation SP10 criteria. In contrast, differences between recorded radial and aortic systolic and pulse pressures were well outside the criteria (respectively, 15.7+/-8.4 and 16.3+/-8.5 for control and 14.5+/-7.3 and 15.1+/-7.3 mm Hg for nitroglycerin). Use of a generalized transfer function to synthesize radial artery pressure waveforms can provide substantially equivalent values of aortic systolic, pulse, mean, and diastolic pressures.

Aged↗
PubMed1989

[The usefulness of lumbar epidural pressure as an index of intracranial pressure].

The reliability of lumbar intraspinal epidural pressure (ISEDP) as an index of intracranial pressure was investigated in seven patients with high intracranial pressure following neurosurgery. ISEDP and intracranial epidural pressure (ICEDP) were measured simultaneously, the latter by the conventional method. ISEDP was measured with a Gaeltec catheter-tip pressure transducer placed percutaneously in the lumbar epidural space via Touhy's needle. In five of seven patients, the ISEDP value was consistently 70 to 100% of the ICEDP value. In all patients, ISEDP always fluctuated in parallel with ICEDP, and the time courses of both were quite similar in response not only to normal cardiac pulsation but also to various manipulations, such as neck compression, coughing, breath holding, mannitol administration, and compression at the cranial defect. In one patient with communicating hydrocephalus following subarachnoid hemorrhage, the relationship between ISEDP and cerebrospinal fluid (CSF) pressure was studied. Upon gradual withdrawal of CSF, ISEDP decreased in parallel with CSF pressure until the latter reached 8 mmHg. Below 8 mmHg CSF pressure, ISEDP did not correlate with CSF pressure. This phenomenon was attributed to slackness of the dural sac due to lowering of CSF pressure, which severed contact between the spinal dural theca and the sensor. Although the discrepancy between ISEDP and ICEDP was prominent in some patients, especially those with low intracranial pressure or blockage of the subarachnoid space, in this study ISEDP reliably reflected ICEDP. The results suggest that ISEDP measurement is useful in monitoring intracranial pressure in patients with increased intracranial pressure. Also, the procedure is simple and relatively noninvasive.

Adult↗
PubMed1976

Isofiltration capillary pressure and compartmental vascular resistances following elevation of venous pressure in subcutaneous tissue.

Isofiltration technique was used to measure the functional capillary pressure in 10 canine hindpaw (mainly subcutaneous tissue) preparations. With simultaneous determinations of arterial pressure, blood flow and venous pressure, the changes in total, precapillary and postcapillary resistances were assessed at different levels of venous pressure. When the tibial arterial pressure was 100 mm Hg. at an initial venous pressure of 5 mm Hg, the isofiltration capillary pressure averaged 12.8 mm Hg, the ratio of pre-to post-capillary resistance 9.9. The precapillary resistance accounted for 90.8% of the total vascular resistance. The isofiltration capillary pressures were 24.9 and 38.0 mm Hg, respectively when venous pressure was elevated to 20 and 35 mm Hg. Capillary pressure (Pc) was approximately related to venous pressure (Pv) by: Pc=0.82Pvm8. Upon elevation of venous pressure, the total and precapillary resistances were not significantly altered. The paw resistance vessels possess neither myogenic nor metabolic autoregulation. With increasing venous pressure, presumably due to passive distension of venules, the postcapillary resistance fell and the ratio of pre-to post-capillary resistance increased.

Animals↗
PubMedDate not supplied

Toe blood pressure. A valuable adjunct to ankle pressure measurement for assessing peripheral arterial disease.

Ankle pressure measurements fail to reflect the severity of peripheral ischemia when the underlying vessels are calcified or when there is extensive pedal or digital arterial disease. These problems may be obviated by measuring pressures at toe level. In this study, toe pressures were correlated with ankle pressures, clinical symptoms, and the presence or absence of diabetes in 294 limbs. The relationship of toe pressures to healing of ulcers or amputations of the foot was investigated in 58 limbs. Measurements were made with a digital pneumatic cuff and a photoplethysmograph. The ability of absolute toe pressure, ankle/brachial index, toe/brachial index, toe/ankle index, and the brachial pressure minus the toe pressure to differentiate between asymptomatic, claudicating, and ischemic limbs was determined. The toe/brachial index, arm minus toe pressure, and the absolute toe pressure had an average sensitivity and specificity of 85% and 88% for asymptomatic limbs and 89% and 86% for ischemic limbs. A toe pressure greater than 30 mmHg was indicative of a good healing potential, and ankle pressure less than 80 mmHg was associated with poor healing. The correlation between ankle and toe pressures was essentially the same in both diabetic (r = 0.60) and non-diabetic limbs (r = 0.62).

Amputation, Surgical↗
PubMedDate not supplied

[The indices of pressure variability by noninvasive ambulatory monitoring of the arterial pressure. A study in 2 normotensive and hypertensive populations].

OBJECTIVE: Analysis of different indices of blood pressure (BP) variability using the ambulatory blood pressure monitoring (ABPM) method in two populations of hypertensive patients (HTA Group) and normotensive volunteers (NOR Group). SETTING: Noninvasive prospective ambulatory study to assess the alterations of the circadian blood pressure profile through ABPM indices of blood pressure variability. PATIENTS: Patients with the diagnosis of essential arterial hypertension referred for clinical investigation to the Cardiology Department of Egas Moniz Hospital in Lisbon. MATERIAL AND METHODS: 40 hypertensive patients (HTA Group) and 30 normal subjects (NOR Group) were included in this study. We calculated the short and long term variability indices. The short term variability indices were the casual and mean immediate BP deviation, percentage of BP peaks and BP peak relative deviation and maximal range variation. Some clinical and general factors considered were namely age, gender, height, weight, body area and index, mean and casual systolic-diastolic blood pressure. RESULTS: Concerning systolic blood pressure in hypertension Vs normal groups respectively, the casual BP deviation was 15 +/- 4 mmHg and 7 +/- 4 mmHg (p 0.003), the mean immediate BP deviation was 18.5 +/- 4 mmHg and 7.5 +/- 3 mmHg (p 0.002), the percentage of BP peaks was 27 +/- 6% (p < 0.001), the percentage of BP peak area was 29 +/- 7% and 6 +/- 3% (p 0.001) and the percentage of relative deviation was 14 +/- 4% and 8 +/- 3% (p 0.03). For diastolic blood pressure all differences were not statistically significant between the two groups and the same happened for systolic blood pressure in relation to standard deviation and maximal range variation. Among these parameters and general and clinical characteristics, the systolic mean and casual blood pressure level showed an acceptable correlation with mean immediate deviation (R = 0.54/0.49), percentage of BP peaks (R = 0.56/0.49) and percentage of BP peak area (R = 0.60/0.53). CONCLUSIONS: Blood pressure variability can be adequately evaluated through the method of ambulatory blood pressure monitoring. Some variability indices can be extracted from the 24 hour curves of ambulatory blood pressure monitoring. Long-term variability indices are not related to the level of blood pressure. In the hypertension group we found a greater variability concerning short term indices, namely immediate deviation, percentage and are of peak curve.

Adult↗
PubMedDate not supplied

[Role of renal interstitial pressure on chronic control of arterial blood pressure].

Several lines of evidence support the hypothesis that the kidney is involved in the generation and maintenance of arterial hypertension. The evidence comes from: 1) experimental models of hypertension showing that induction of all secondary forms of hypertension require some maneuvers to reduce the renal sodium and water excretion; 2) the existence of several rat models with genetic hypertension exhibiting a shift of the pressure-natriuresis relationship toward higher pressures; 3) renal transplantation experiments between normal and genetically hypertensive rats showing that hypertension follows the kidney; and 4) human genetic disease with chronic changes in arterial blood pressure levels in which all identified genes so far are part of a common pathway for renal sodium reabsorption. It is well known that pressure-natriuresis is the mechanisms by which any changes in arterial pressures are followed by changes in renal sodium excretion. However, it has been recognized now that the interstitial pressure in renal medulla is the linkage between arterial pressure levels and the amount of sodium reabsorption. Thus, the medullary interstitial pressure might be involved in the long-term control of systemic arterial pressure. Part of these new lines of evidence associating the renal medullary interstitial pressure in the control of arterial pressure are due to the availability of new methods such as laser-doppler flowmetry and videomicroscopy, that allows the measurement of blood flow in renal cortex and medulla separately. Several studies with this methodology show that medullary, but not cortical pressure and blood flow correlate positively with natriuresis. What still remains unsolved is the mechanism by which renal sodium reabsorption increases or decreases after changes in the medullary interstitial pressure occur.

Animals↗
PubMed2003

Right atrial pressure as a measure of ventricular constraint arising from positive end-expiratory pressure during mechanical ventilation of the neonatal lamb.

OBJECTIVE: By constraining the heart, the chest wall, lungs, and pericardium limit diastolic filling and thus have a major role in determining cardiac output. Although intermittent positive pressure ventilation and the application of positive end-expiratory pressure amplifies this constraint, no clinical method exists to assess the impact that positive end-expiratory pressure has on ventricular constraint in the newborn. In this study, we tested the hypothesis that a change in right atrial pressure (Pra) reflects the change in ventricular constraint associated with a change in airway pressure. DESIGN: Experimental, comparative animal study. SETTING: Ritchie Centre for Baby Health Research cardiovascular laboratory. SUBJECTS Neonatal (4-wk-old, n = 6) and newborn (3-day-old, n = 6) Merino/Border-Leicester cross lambs. INTERVENTIONS: Lambs were anesthetized (alpha-chloralose and ketamine), ventilated, and instrumented to record Pra, thoracic inferior vena caval pressure (Pivc, saline-filled catheters), and pericardial pressure (Pper, liquid-containing balloon). MEASUREMENTS AND MAIN RESULTS: Changes (Delta) in Pra, Pivc, and Pper were assessed while airway pressure was rapidly reduced from four set levels of continuous positive airway pressure (2.5, 5, 7.5, and 15 cm H2O) to atmospheric pressure. A strong linear relationship was observed between DeltaPra and DeltaPper (DeltaPra = 0.90 DeltaPper - 0.02, r =.98), and between DeltaPivc and DeltaPper (DeltaPivc = 0.86 DeltaPper - 0.02, r =.98) in both the 4-wk-old lambs and the 3-day-old lambs. CONCLUSIONS: Our experiments demonstrate that, in the newborn and neonatal lamb, DeltaPra provides an accurate measure of the change in ventricular constraint that accompanies a change in airway pressure, and thus may provide a means of quantifying the magnitude of ventricular constraint imposed by positive end-expiratory pressure and mechanical ventilation during neonatal intensive care.

Age Factors↗
PubMed1975

Effect of increased intraabdominal pressure on lower esophageal sphincter pressure.

This study evaluates the effect of intraabdominal pressure increases on lower esophageal sphincter (LES) pressure in normal subjects and in patients with reflux esophagitis. Intraabdominal and intragastric pressure were increased by abdominal compression, the Valsalva maneuver, and leg raising. In normal subjects changes in pressure recorded from the LES equaled the changes in gastric pressure induced by abdominal compression and Valsalva. Consquently the LES-gastric pressure gradient remained unchanged. During leg raising, pressure recorded from the LES increased more than gastric pressure, thereby increasing the LES-gastric pressure gradient. Although statistically significant, the LES pressure increases associated with leg raising were modest, unrelated to initial sphincter pressure, and unaffected by atropine. When individuals demonstrating a "common cavity" phenomenon were exculed, LES pressure changes during abdominal compression were similar in patients with esophagitis and in normal volunteers. Consequently, response of the LES to abdominal compression generally does not separate patients with esophagitis from normal subjects. We believe that the LES responses to increased intra-abdominal pressure observed in this study are better accounted for by mechanical factors than by a physiologic adaptive response of intrinsic LES tone.

Abdomen↗
PubMed1999

Estimation of beat-to-beat changes in stroke volume from arterial pressure: a comparison of two pressure wave analysis techniques during head-up tilt testing in young, healthy men.

OBJECTIVE: The aim of this study was to compare beat-to-beat changes in stroke volume (SV) estimated by two different pressure wave analysis techniques during orthostatic stress testing: pulse contour analysis and Modelflow, i.e., simulation of a three-element model of aortic input impedance. METHODS: A reduction in SV was introduced in eight healthy young men (mean age, 25; range, 19-32 y) by a 30-minute head-up tilt maneuver. Intrabrachial and noninvasive finger pressure were monitored simultaneously. Beat-to-beat changes in SV were estimated from intrabrachial pressure by pulse contour analysis and Modelflow. In addition, the relative differences in Modelflow SV obtained from intrabrachial pressure and noninvasive finger pressure were assessed. RESULTS: Beat-to-beat changes in Modelflow SV from intrabrachial pressure were comparable with pulse contour measures. The relative difference between the two methods amounted to 0.1+/-1% (mean +/- SEM) and was not dependent on the duration of tilt. The difference between Modelflow applied to intrabrachial pressure and finger pressure amounted to -2.7+/-1.3% (p = 0.04). This difference was not dependent on the duration of tilt or level of arterial pressure. CONCLUSIONS: Based on different mathematical models of the human arterial system, pulse contour and Modelflow compute similar changes in SV from intrabrachial pressure during orthostatic stress testing in young healthy men. The magnitude of the difference in SV derived from intrabrachial and finger pressure may vary among subjects; Modelflow SV from noninvasive finger pressure tracks fast and brisk changes in SV derived from intrabrachial pressure.

Adult↗
PubMed2003

Pressure breathing in fighter aircraft for G accelerations and loss of cabin pressurization at altitude--a brief review.

PURPOSE: The purpose of this brief review is to outline the past and present use of pressure breathing, not by patients but by fighter pilots. SOURCE: Of the historical and recent references quoted, most are from aviation-medicine journals that are not often readily available to anesthesiologists. PRINCIPAL FINDINGS: Pressure breathing at moderate levels of airway pressure gave World War II fighter pilots a tactical altitude advantage. With today's fast and highly maneuverable jet fighters, very much higher airway pressures of the order of 8.0 kPa (identical with 60 mmHg) are used. They are used in conjunction with a counterpressure thoracic vest and an anti-G suit for the abdomen and lower body. Pressurization is activated automatically in response to +Gz accelerations, and to a potentially catastrophic loss of cabin pressurization at altitude. During +Gz accelerations, pressure breathing has been shown to maintain cerebral perfusion by raising the systemic arterial pressure, so increasing the level of G-tolerance that is afforded by the use of anti-G suits and seat tilt-back angles alone. This leaves the pilot less reliant on rigorous, and potentially distracting, straining maneuvers. With loss of cabin pressurization at altitude, pressure breathing of 100% oxygen at high airway pressures enables the pilot's alveolar PO(2) to be maintained at a safe level during emergency descent. CONCLUSION: Introduced in military aviation, pressure breathing for G-tolerance and pressure breathing for altitude presented as concepts that may be of general physiological interest to many anesthesiologists.

Acceleration↗
PubMed2004

Static pressure-volume curve characteristics are moderate estimators of optimal airway pressures in a mathematical model of (primary/pulmonary) acute respiratory distress syndrome.

OBJECTIVE: To study the value of objective pressure-volume characteristics for predicting optimal airway pressures and the development of atelectasis and overstretching during a structured lung volume recruitment procedure with subsequent reduction in airway pressures. METHODS: We used a mathematical model of a lung with adjustable characteristics of acute respiratory distress syndrome (ARDS) characteristics. Simulations were performed in five grades of ARDS in the presence of pure alveolar or combined alveolar-small airway closure as well complete or incomplete lung volume recruitability. For each simulation optimal end-expiratory pressure was determined. A static pressure-volume curve was constructed and objective characteristics of this curve calculated. The predictive value of these characteristics for end-expiratory atelectasis, overstretching, and optimal end-expiratory pressure was assessed. RESULTS: Simultaneous alveolar recruitment and overstretching during inflation were more pronounced than alveolar derecruitment and overstretching during deflation. End-expiratory pressure needed to prevent significant alveolar collapse in severe ARDS resulted in maximal safe tidal volumes that may be insufficient for adequate ventilation using conventional mechanical ventilatory modes. Plateau pressures well below the "upper corner point" (airway pressure where compliance decreases) resulted in significant alveolar overstretching. CONCLUSIONS: A recruitment maneuver followed by subsequent reduction in airway pressure limits end-expiratory atelectasis, overstretching, and pressure. None of the objective characteristics of the pressure-volume curve was predictive for end-expiratory atelectasis, overstretching, or optimal airway pressure.

Humans↗
PubMed1995

Urethral closure pressure and leak-point pressure in incontinent women.

OBJECTIVE: To examine the association between maximum urethral closure pressure and Valsalva leak-point pressure in women with genuine stress incontinence (GSI). METHODS: Fifty-six women with GSI were evaluated in a urodynamics laboratory. Maximum urethral closure pressure and vesical leak-point pressure were measured with multichannel urodynamic testing. The correlation coefficient and regression line were calculated. RESULTS: Forty subjects demonstrated a leak on Valsalva maneuver and, in these women, maximum urethral closure pressure and leak-point pressures were related significantly (r = 0.62, P < .001). The relationship was strongest between leak-point pressure up to 120 cm H2O and absolute vesical pressure with Valsalva rather than with a change in vesical pressure. The sensitivity of leak-point pressure for predicting low urethral pressure was 100%. CONCLUSION: There is a correlation between maximum urethral closure pressure and leak-point pressure that can provide useful information about incontinence in women.

Female↗
PubMed1993

Response of the interatrial septum to transatrial pressure gradients and its potential for predicting pulmonary capillary wedge pressure: an intraoperative study using transesophageal echocardiography in patients during mechanical ventilation.

OBJECTIVES: We hypothesized that the directional movement of the interatrial septum and its curvature may reflect the pressure relations between the left and right atria. BACKGROUND: Interventricular septal shape is primarily dependent on the pressure gradient between the left and the right ventricle. No analogous study has carefully evaluated the determinants of interatrial septum shape and motion. METHODS: Patients (n = 52) undergoing cardiac or vascular surgery were studied intraoperatively at multiple intervals with transesophageal echocardiography and simultaneous measurement of central venous pressure, pulmonary capillary wedge pressure and airway pressure. RESULTS: Overall interatrial septum shape, which usually curved toward the right atrium, changed concordantly with the interatrial pressure gradient (pulmonary capillary wedge pressure-central venous pressure difference). The degree of interatrial septum curvature was also primarily dependent on the interatrial pressure gradient and, to a lesser extent, was affected by changes in left atrial size (F = 130.4 vs. F = 14.1). During passive mechanical expiration, the interatrial pressure gradient, usually positive, often reverses transiently and the interatrial septum momentarily bows toward the left atrium. Midsystolic reversal was seen in 64 of 72 episodes when the pulmonary capillary wedge pressure was < or = 15 mm Hg but in only 2 of 40 episodes when it was > 15 mm Hg (sensitivity = 0.89, specificity = 0.95, positive predictive value = 0.97). CONCLUSIONS: These findings suggest that overall interatrial septum shape depends on the pressure gradient between the left and right atria. Midsystolic reversal of the interatrial septum, which probably reflects the increased venous return in the right relative to the left atrium during mechanical expiration, may be a useful indicator of the pulmonary capillary wedge pressure.

Atrial Function↗
PubMed1997

Prediction of young adult blood pressure from childhood blood pressure, height, and weight.

To assess the ability of childhood blood pressure, height, and weight to predict young adult blood pressure, the authors examined data obtained over multiple visits for four years on 339 children aged 8-18 years in East Boston, Massachusetts. These subjects were again seen 8-12 years later when they were aged 20-26 years. Multivariate regression models were used to predict true blood pressure in young adulthood from observed childhood measurements closest to age 10 (n = 219), adjusting for within-person variability. Without adjusting for childhood blood pressure, childhood height, weight and body mass index were at least marginally associated with young adult systolic blood pressure in boys and girls, with similar coefficients for each gender. The strongest predictor was weight (beta = 0.6 mmHg/10 lbs for girls, and beta = 0.7 mmHg/10 lbs for boys), and height was no longer predictive with weight in the model. With childhood blood pressure included, neither childhood height nor weight were predictors of future systolic blood pressure. However, change in height and weight were predictors of future systolic blood pressure. Weight change was a stronger predictor in girls than boys with beta = 0.9 mmHg/10 lbs. For diastolic blood pressure, height and weight had limited predictive ability in these data. These models, which allow for both between- and within-person variability in young adulthood, may be used to estimate the predictive value for future high blood pressure of a child's current blood pressure, height and weight, as well as future change in height and weight. These data suggest that the effects of childhood height and weight on future blood pressure may be negligible given childhood blood pressure, but that later height and weight remain predictive.

Adolescent↗
PubMed2001

Pressure sores in intensive care: defining their incidence and associated factors and assessing the utility of two pressure sore risk assessment tools.

Patients in intensive care units (ICU) are at high risk of developing pressure sores and the use of pressure sore risk tools has been advocated as a means of identifying patients at risk. A prospective multi-site observational study was conducted to define the incidence of pressure sores, assess two pressure sore risk scales and to define risk factors relevant to intensive care. Patients (n = 534) were assessed for the presence of pressure sores. The Waterlow and Jackson/Cubbin risk scales were completed each day for 314 and 188 of these patients respectively. A total of 75 pressure sores were recorded. Of these, 34 were present on admission. Of the remaining 41, 16 were classified as Grade 1 and 24 as Grade 2 sores. The pressure sore (PS) incidence was 5.2 per cent. Expressed as PS/1000 patient days there were 18.48 pressure sores per 1000 patient days. The ability of the risk scores to predict pressure sores was tested using a Receiver Operating Characteristic (ROC) analysis. The association of risk score with pressure sores was analysed using a survival function (Kaplan Meier) and variables compared using a logrank test (Mantel-Cox). Factors associated with pressure sore occurrence were developed and tested using a survival regression model. Both risk scales were poor predictors of pressure sores (ROC curve area approximately 70 per cent for both). The factors, coma/unresponsiveness/paralysed & sedated and cardiovascular instability were significantly associated with pressure sores with relative risks of 4.2 and 2.5 respectively. Risk increased as a function of time such that the cumulative risk was 50 per cent at 20 days.

Adolescent↗
PubMed2002

Relationship between blood pressure level in early pregnancy and subsequent changes in blood pressure during pregnancy.

BACKGROUND: It is not known whether women with high blood pressure in the first trimester are likely to exhibit a large increase in blood pressure during pregnancy. METHODS: We conducted a retrospective, longitudinal study of 1599 pregnant women, among whom 29 women (1.8%) received antihypertensive medication during pregnancy. The blood pressure levels measured during the first (7.9 +/- 2.4 weeks), second (20.7 +/- 1.2 weeks) and third trimesters (38.4 +/- 1.7 weeks) were analyzed. The obstetric outcomes were examined in five subgroups divided according to the quintile of the first-trimester mean arterial pressure level. RESULTS: The net change in blood pressure levels (third-trimester value minus first-trimester value) was significantly inversely correlated with the first-trimester blood pressure levels irrespective of the use or lack of use of antihypertensive drugs. Women with the highest quintile first-trimester mean arterial pressure had the largest body weight, exhibited a fall in blood pressure and had the smallest increase in body weight during pregnancy, and were significantly more likely to have a growth-restricted infant. CONCLUSIONS: Women with high initial blood pressure tended to exhibit a fall in blood pressure, whereas women with low initial blood pressure tended to exhibit a large increase in blood pressure during pregnancy. Women with high initial blood pressure and a small increase in body weight during pregnancy tended to have growth-restricted infants.

Adolescent↗