Non-invasive Blood Pressure Recordings Research Articles

Moving On—On Average in the Right Direction?

See related article, p 865–870 For >100 years, aortic hemodynamics have been the subject of systematic physiological investigations. Already in the early days, Otto Frank introduced the Windkessel model to describe the aorta, in particular, its function as cushion against cardiac pulsatility, providing reduced pressure load to large vessels. In engineering terms, this behavior of the aorta can be described by a low-pass filter. In contrast to the intermittent pumping left ventricle with consecutive pulsatile pressure and flow in the aorta and the large arteries, the microcirculation is designed to provide virtually steady blood flow at low pressure for the maintenance of proper organ perfusion. This modification of pressure and flow is achieved mainly by variation of vessel diameter and wall composition and can be monitored through changes in the amplitude and shape of pressure and flow pulses downward the arterial bed. With respect to the large arteries, central (ascending aortic) systolic pressures and central pulse pressures are lower than their counterparts at the sites of noninvasive blood pressure recordings (usually at the brachial artery), whereas diastolic pressure is almost equal. This effect is called aortic to peripheral systolic or pulse pressure amplification and depends among other factors on age and the elastic properties …

Ambulatory non-invasive blood pressure recording in a freely moving cynomolgus monkey using High Definition Oscillometry (HDO) and Bluetooth technology

Ambulatory non-invasive blood pressure recording in a freely moving cynomolgus monkey using High Definition Oscillometry (HDO) and Bluetooth technology

The Mean Prehospital Machine; accurate prehospital non-invasive blood pressure measurement in the critically ill patient

Non-invasive blood pressure recordings may be inaccurate in the critically ill patient and measurement difficulties are intensified in the prehospital setting. This may adversely impact upon outcomes for many critically ill patients, particularly those with traumatic brain injury and/or lengthy prehospital times. This study aimed to validate a non-invasive, oscillometric, ambulatory blood pressure measuring device, the Oscar 2, Model 222 (SunTech Medical, Morrisville, USA) during the ambulance transport of critically ill patients. We have previously shown that mean arterial blood pressures observed by Intensive Care Unit nurses from a patient monitor can be considered interchangeable with reference intra-arterial integrated mean pressures. In the current study, we compared non-invasive device mean pressures to intra-arterial pressures observed by retrieval nurses from the patient monitor, during the ambulance transportation of critically ill patients. Device performance was required to fulfil the Association for the Advancement of Medical Instrumentation (AAMI) protocol requirements. Additionally, linear mixed effects analyses and Bland-Altman comparisons were undertaken. For 157 measurements recorded from 23 patients, when the Oscar 2 did not indicate a measurement was associated with a fault, the device fulfilled the AAMI protocol requirements, with a mean error of -1.1 mmHg (standard deviation 7.8 mmHg), 95% confidence intervals (linear mixed effects analysis) -2.9, 0.8; P = 0.26. Bland-Altman plots indicated uniform agreement across a wide range of blood pressures. Sixteen percent of recordings were associated with a patient, environment, or device generated fault. When the Oscar 2 does not indicate a fault has occurred, clinicians may be confident the mean pressure, within acceptable limits, is accurate, even during ambulance motion, administration of high doses of vasopressors and mechanical ventilation. The Oscar 2 appears to be an accurate and rugged out-of-hospital device.

Pressor and Baroreflex Effects of Ouabain in (mRen2)27 and mRen2.Lewis Rats

Previous studies show that endogenous ouabain, a cardiac digitalis‐like compound, may play a role in development of elevated pressure. The current study investigated the effect of acute intravenous (i.v.) ouabain on mean arterial blood pressure (MAP) in (mRen2)27 and mRen2.Lewis rats models of hypertension. Non‐invasive blood pressure recordings verified elevated systolic pressure in conscious rats. Under urethane/chloralose anesthesia, MAP was normalized in (mRen2)27 and mRen2.Lewis rats (101 ± 6 mmHg and 84.6 ± 6 mmHg). I.V. ouabain (40 μg/kg/bwt) increased MAP to 25% above baseline in (mRen2)27 and 45% in mRen2.Lewis rats, returning to baseline within 30 minutes. The effect of ouabain on baroreceptor reflex sensitivity (BRS) was measured before and after ouabain treatment. At baseline, BRS was similar in (mRen2)27 and mRen2.Lewis rats (0.49 ± 0.13 vs 0.37 ± 0.08 msec/mm Hg). BRS was decreased following ouabain injections in mRen2.Lewis animals (0.005 ± 0.01 msec/mm Hg; p < 0.05 vs baseline) but was unaffected in (mRen2)27 (0.37 ± 0.07 msec/mm Hg). Thus, an exacerbated pressor response was associated with suppression of the BRS in mRen2.Lewis rats. MD000232, MD002303, HL51952

Noninvasive blood pressure cuff causing humerus fracture

Blood pressure recording is a part of the routine set of initial observations for any patient. It is performed by variety of medical and paramedical personnel universally. Bone metastases and pathologic fracture of the bone are common in the elderly patient. Noninvasive blood pressure recording is innocuous procedure, although on rare occasions can cause iatrogenic fracture of the asymptomatic pathologic bone. This case report highlights the importance of vigilance to look for pain and tender area over the site of blood pressure cuff placement and before its inflation to record blood pressure, as it can be "traumatic" for the asymptomatic weak pathologic bone leading to a fracture. Iatrogenic fracture can add to the burden of a patient's medical problem, necessitating secondary surgical procedure, delaying recovery, and having the possibility of medicolegal problems.

Noninvasive assessment of arterial pressure

To briefly review recent advances in the noninvasive assessment of arterial pressure (indirect methods) in the field of critical care. Automated oscillometric measurements underestimate intraarterial systolic blood pressure. Digital photoplethysmography has led to conflicting results, although the obtained respiratory pulse pressure variation correlates with the fluid-challenge-induced changes in stroke volume. The pulse oximetry photoplethysmographic signal recorded at the digital or ear level may be useful in monitoring respiratory arterial pressure variations, although technical improvements and clarifications are needed. Arterial tonometry is increasingly used in the cardiovascular field to reconstruct central aortic pressure. A recent study has shown that radial artery tonometry is feasible in hemodynamically stable patients and that peripheral pulse pressure reflects the combined influences of arterial stiffness and stroke volume, especially in elderly patients. The limitations of this technique include the potential bias related to the use of a generalized transfer function and the difficulty in obtaining reliable recordings in hemodynamically unstable patients. Intraarterial blood pressure must be preferred over noninvasive blood pressure recordings when critical decisions are required. In hemodynamically stable patients, valuable information may be obtained by using noninvasive techniques, amongst which arterial tonometry seems especially promising.

Evaluation of the SCHILLER BR-102 plus noninvasive ambulatory blood pressure monitor according to the International Protocol introduced by the Working Group on Blood Pressure Monitoring of the European Society of Hypertension

To evaluate the SCHILLER BR-102 plus (Schiller AG, Baar, Switzerland) noninvasive ambulatory blood pressure recorder according to the International Protocol for validation of blood pressure measuring devices in adults introduced by the Working Group on Blood Pressure Monitoring of the European Society of Hypertension. One SCHILLER BR-102 plus blood pressure recorder was tested by a validation team, consisting of three persons: two observers (nurses) and a doctor, acting as supervisor and 'expert'. The European Society of Hypertension International Protocol comprises two phases. Fifteen participants were recruited for the first phase and, following a successful test, a further 18 persons (giving a total of 33) were recruited additionally. For phase 1, five of the 15 participants had systolic blood pressure and diastolic blood pressure in each of the ranges: low, medium and high. For phase 2, 11 of the 33 participants (including the first 15 participants) had systolic blood pressure and diastolic blood pressure in each of the ranges. The mercury standard for validation was preferred over the optional Sphygmocorder. Because the SCHILLER BR-102 plus has the oscillometric method as backup to the basic auscultatory measurement, both systems of measurement were subjected to individual validations. Results obtained show that the SCHILLER BR-102 plus noninvasive ambulatory blood pressure recorder meets all the requirements specified in the International Protocol for both oscillometric and auscultatory methods. On the basis of these results, the SCHILLER BR-102 plus can be recommended for ambulatory blood pressure measurement in clinical practice using both auscultatory and oscillometric modes.

Comparison of noninvasive oscillometric and intra-arterial blood pressure measurements in hyperacute stroke

This study aims to compare automatic oscillometric blood pressure recordings with simultaneous direct intra-arterial blood pressure measurements in hyperacute stroke patients to test the accuracy of oscillometric readings. A total of 51 first-ever stroke patients underwent simultaneous noninvasive automatic oscillometric and intra-arterial blood pressure monitoring within 3 h of ictus. Casual blood pressure was measured in both arms using a standard mercury sphygmomanometer on hospital admission. Patients who received antihypertensive medication during the blood pressure monitoring were excluded. The estimation of systolic blood pressure (SBP) using oscillometric recordings underestimated direct radial artery SBP by 9.7 mmHg (95% confidence interval: 6.5-13.0, P<0.001). In contrast, an upward bias of 5.6 mmHg (95% confidence interval: 3.5-7.7, P<0.001) was documented when noninvasive diastolic blood pressure (DBP) recordings were compared with intra-arterial DBP recordings. For SBP and DBP, the Pearson correlation coefficients between noninvasive and intra-arterial recordings were 0.854 and 0.832, respectively. When the study population was stratified according to SBP bands (group A: SBP<or=160 mmHg; group B: SBP>160 mmHg and SBP<or=180 mmHg, group C: SBP>180 mmHg), higher mean DeltaSBP (intra-arterial SBP-oscillometric SBP) levels were documented in group C (+19.8 mmHg, 95% confidence intervals: 12.2-27.4) when compared with groups B (+8.5 mmHg, 95% confidence intervals: 2.7-14.5; P=0.025) and A (+5.9 mmHg, 95% confidence intervals: 1.8-9.9; P=0.002). Noninvasive automatic oscillometric BP measurements underestimate direct SBP recordings and overestimate direct DBP readings in acute stroke. The magnitude of the discrepancy between intra-arterial and oscillometric SBP recordings is even more prominent in patients with critically elevated SBP levels.

Analysis of cardiovascular oscillations: A new approach to the early prediction of pre-eclampsia

Pre-eclampsia (PE) is a serious disorder with high morbidity and mortality occurring during pregnancy; 3%-5% of all pregnant women are affected. Early prediction is still insufficient in clinical practice. Although most pre-eclamptic patients show pathological uterine perfusion in the second trimester, this parameter has a positive predictive accuracy of only 30%, which makes it unsuitable for early, reliable prediction. The study is based on the hypothesis that alterations in cardiovascular regulatory behavior can be used to predict PE. Ninety-six pregnant women in whom Doppler investigation detected perfusion disorders of the uterine arteries were included in the study. Twenty-four of these pregnant women developed PE after the 30th week of gestation. During pregnancy, additional several noninvasive continuous blood pressure recordings were made over 30 min under resting conditions by means of a finger cuff. The time series extracted of systolic as well as diastolic beat-to-beat pressures and the heart rate were studied by variability and coupling analysis to find predictive factors preceding genesis of the disease. In the period between the 18th and 26th weeks of pregnancy, three special variability and baroreflex parameters were able to predict PE several weeks before clinical manifestation. Discriminant function analysis of these parameters was able to predict PE with a sensitivity and specificity of 87.5% and a positive predictive value of 70%. The combined clinical assessment of uterine perfusion and cardiovascular variability demonstrates the best current prediction several weeks before clinical manifestation of PE.

A combined technique for predicting pre-eclampsia: concurrent measurement of uterine perfusion and analysis of heart rate and blood pressure variability

Pre-eclampsia is a serious complication of pregnancy with high morbidity and mortality and an incidence of 3-5% in all pregnancies. Early prediction is still insufficient in clinical practice. Although most pre-eclamptic patients have pathological uterine perfusion in the second trimester, perfusion disturbance has a positive predictive accuracy (PPA) only of approximately 30%. Non-invasive continuous blood pressure recordings were taken simultaneously via a finger cuff for 30 min. Time series of systolic as well as diastolic beat-to-beat pressure values were extracted to analyse heart rate and blood pressure variability and baroreflex sensitivity in 102 second-trimester pregnancies, to assess predictability for pre-eclampsia (n = 16). All women underwent Doppler investigations of the uterine arteries. We identified a combination of three variability and baroreflex parameters to best predict pre-eclampsia several weeks before clinical manifestation. The discriminant function of these three parameters classified patients with later pre-eclampsia with a sensitivity of 87.5%, a specificity of 83.7%, and a PPA of 50.0%. Combined with Doppler investigations of uterine arteries, PPA increased to 71.4%. This technique of incorporating one-stop clinical assessment of uterine perfusion and variability parameters in the second trimester produces the most effective prediction of pre-eclampsia to date.

Autonomic Cardiovascular Control in Pregnancies With Abnormal Uterine Perfusion

Abnormal uterine perfusion is associated with the development of hypertensive pregnancy disorders. However, its impact on maternal autonomic cardiovascular control is poorly understood. The aim of our study was to investigate the adaptation of autonomic control during pregnancy with abnormal uterine perfusion with normal and pathologic outcome in comparison to normal pregnancies. based on blood pressure variability (BPV), baroreflex sensitivity (BRS), and heart rate variability (HRV) analyses. A total of 32 healthy pregnant women (CON, age 28 years, range 24 to 31 years); 16 women with abnormal uterine perfusion and normal outcome (AP-NO, age 29 years, range 28 to 33 years); and 19 women with abnormal uterine perfusion and pathologic outcome (AP-PO, age 26 years, range 25 to 30 years), were recruited for this longitudinal study. Beginning in the 20th week of pregnancy, the women were monitored every fourth week until delivery. For the analysis of BPV, BRS, and HRV, high-resolution ECG, and noninvasive continuous blood pressure (BP) recordings were taken simultaneously for 30 minutes. CON showed pregnancy-induced adaptation of cardiovascular control; in the course of gestation BPV was increased while parameters of HRV and BRS were reduced. On the contrary, no changes during the second half of pregnancy could be observed in pregnancies with abnormal perfusion. Variability parameters were significantly altered in women with abnormal perfusion compared with CON, whereas these changes were more pronounced in AP-PO compared with AP-NO. Abnormal uterine perfusion, independently of the pregnancy outcome, has a significant impact on maternal cardiovascular control. Measures of BPV, BRS and HRV might be used for improved risk stratification.

Noninvasive measurement of blood pressure variability: accuracy of the Finometer monitor and comparison with the Finapres device

To assess the accuracy of spectral indices of arterial pressure variability and baroreflex sensitivity obtained from beat-by-beat noninvasive blood pressure recordings by the Finometer device, we compared these measures with those obtained from intra-arterial recordings. The performance of the Finometer was also compared to the traditional Finapres device. In 19 cardiac disease patients, including myocardial infarction, heart failure and cardiac transplant, we estimated the power of systolic and diastolic pressures in the VLF (0.01–0.04 Hz), LF (0.04–0.15 Hz) and HF (0.15–0.45 Hz) bands and computed absolute and percentage errors relative to intra-arterial brachial pressure. We also computed the characteristic frequency of each band (i.e. the barycentric frequency of spectral components identified in the band). The variability of systolic pressure in the VLF and LF bands was markedly overestimated by both the Finometer and Finapres (p < 0.01), with percentage median errors of respectively 130% and 103% (Finometer), and 134% and 78% (Finapres). The HF power was substantially unchanged using the Finometer and reduced using the Finapres (−28%, p < 0.05). The limits of agreement between noninvasive and invasive spectral measurements were wide. Linear system analysis showed that most (>80%) of the power of noninvasive signals was linearly related to the power of the invasive signal. The characteristic frequency of each band was substantially preserved in both noninvasive signals. The results for diastolic pressure were similar, but the Finapres errors in the VLF and LF bands were lower. Baroreflex sensitivity was significantly underestimated by both devices (Finometer: −31%, Finapres: −24%). Despite previous studies having shown that brachial artery waveform reconstruction performed by the Finometer has improved the accuracy of blood pressure measurement compared to the Finapres device, measurement of blood pressure variability in cardiac disease patients provides worse results in most spectral parameters and a better accuracy only in the HF band of systolic pressure.

Do SpaceLabs ambulatory non-invasive blood pressure recorders measure blood pressure consistently over several years use?

To assess the measurement consistency of SpaceLabs ambulatory recorders (Spacelabs, Washington, USA) that are in regular use. A total of 14 SpaceLabs 90207 and one 90217 ambulatory recorders were tested for measurement consistency using the Dynatech CuffLink (Dynatech, Nevada, USA), a commercially available non-invasive blood pressure (NIBP) simulator. The NIBP recorders were tested at a range of pressures with 20 repeated determinations at a simulated 120/80 mmHg and five repeated determinations at simulated pressures of 80/50, 100/80, 150/100, 200/165 and 250/195 mmHg. Tests were carried out in 1998, 2002 and late 2003 or early 2004. All 15 SpaceLabs recorders measured consistently over the 6 years with 89.5% of the differences in average pressures, recorded by any particular device at each recorded pressure, less than 2 mmHg between successive test episodes. The maximum difference was 4.5 mmHg and 60.1% of the differences were less than 1 mmHg. The measurements for all devices were within the tolerances specified by the supplier for the device when tested with the simulator. Maintenance records also show that most devices required breakdown maintenance less than once every 3 years. The results show that the SpaceLabs devices maintain measurement consistency in the demanding conditions of ambulatory pressure recording over several years.

Intratumoral Cancer Chemotherapy Through a Flexible Bronchoscope

Intratumoral Cancer Chemotherapy Through a Flexible Bronchoscope

Influence of sleep related hypoxaemia on left ventricular hypertrophy in mild to moderate hypertensives

To evaluate the possible relationship between the nocturnal hypoxaemia and left ventricular hypertrophy (LVH) in patients (pts) with arterial hypertension (AH), we investigated untreated 50 hospitalized pts (mean age 52±2y, 40m and 10f) with mild to moderate AH. Noninvasive 24-h blood pressure (BP) recordings (SpaceLabs 90207 or TM-2425, AD) were performed with intervals of 15 min during the day- and 30 min during the nighttime. Left ventricular mass was assessed by echocardiography (Devereux) and normalized by body surface area (LVMI). The pts underwent 7–8 hours of continuos monitoring (NONIN-8500 M) of arterial oxygen saturation during sleep. The results were analyzed with original program ≪ARM-SaO2≫. The nocturnal hypoxaemia was assessed using the number of 4% desaturation (DN) from the baseline stabile value, during the monitoring. According by tertil values of DN, pts were divided into three groups: Gr.I (DN<10), Gr.II (10≤DN<35) and Gr.III (DN≤35). Differences of estimated parameters between groups were tested by Kruskal-Wallis ANOVA, the prevalence of LVH (LVMI>125 g/m2 for males and LVMI>110 g/m2 for females) - by Fisher's exact test. The relationship between LVMI, LVH and other variables were assessed by Spearman rank order correlation analysis. There were no significant differences between groups by body mass index (29±6 vs 28±3 vs 31±6 kg/m2) and duration of AH (12±9 vs 10±5 vs 11±7 y). The pts in the Gr.I and Gr.II were significantly younger in comparison with Gr.III (49±10. 49±9 vs 57±11 y; p<0.05). There were no significant differences between groups by daytime (D) and nighttime (N) values of systolic and diastolic BP-s (SBP and DBP). LVMI and the presence of LVH were significantly higher in the Gr.III. Spearman rank order correlation analysis showed, that DN significantly correlated with LVMI (0.41, p<0.003) and the presence of LVH (0.32, p<0.05). There is not significant correlation between the age of patients and LVMI (0.2, p=0.1). Our results suggests that the number of nocturnal desaturation is a risk factor for left ventricular hypertrophy in patients with mild to moderate arterial hypertension. (See Table) −P<0.05 Gr.II and Gr.III. −p<0.05 Gr.I and Gr.III −p<0.05 all Gr. −P<0.05 Gr.II and Gr.III. −p<0.05 Gr.I and Gr.III −p<0.05 all Gr.

Dynamic cerebral autoregulation testing as a diagnostic tool in patients with carotid artery stenosis

Evaluation of dynamic cerebral autoregulation might yield a physiologically more adequate measure of cerebral hemodynamic impairment in carotid artery stenosis than CO2-reactivity. This study re-evaluates and compares the Valsalva maneuver (VM) and phase shift during deep breathing. Nineteen patients with severe carotid artery stenosis and 17 age-matched controls were examined using transcranial Doppler sonography and non-invasive blood pressure recordings (Finapres). Phase shift was determined by crossspectral analysis, responses to VM were graded by the formerly-introduced autoregulation slope index (ASI) and the new Valsalva time index (VTI). Phase shift and autoregulatory indices were significantly reduced on the affected side (p < 0.001). Correlations with CO2-reactivity were significant when pooling values of controls and patients (r from 0.54 to 0.78; p < 0.001). Correlations except for the VTI (r = -0.65; p = 0.002) were not significant considering only the affected side in patients. Correlations of pooled values between phase shift and VM-derived indices were significant (VTI r = -0.62; p < 0.001; ASI r = 0.49; p < 0.001), within patients only when comparing side-to-side differences (VTI r= -0.58; p = 0.009; ASI r = 0.52; p = 0.023). In conclusion, detection of impaired cerebral autoregulation is possible both by deep breathing and VM. The new VTI seems to be more suitable than the conventional ASI. Inter-method agreement concerning the extent of impairment is only acceptable for intra-individual side-to-side differences. Since absolute values of one autoregulation testing method or CO2-reactivity alone might fail, various tests should be combined for comprehensive assessment of cerebral hemodynamic impairment. [Neurol Res 2001; 23: 55-63]

Spontaneous oscillations of arterial blood pressure, cerebral and peripheral blood flow in healthy and comatose subjects

Slow and rhythmic spontaneous oscillations of cerebral and peripheral blood flow occur within frequencies of 0.5-3 min~1 (0.008-0.05 Hz, B-waves) and 3-9 min~1 (0.05-0.15 Hz, M-waves). The generators and pathways of such oscillations are not fully understood. We compared the coefficient of variance (CoV), which serves as an indicator for the amplitude of oscillations and is calculated as the percent standard deviation of oscillations within a particular frequency band from the mean, to study the impairment of generators or pathways of such oscillations in normal subjects and comatose patients in a controlled fashion. With local ethic committee approval, data were collected from 19 healthy volunteers and nine comatose patients suffering from severe traumatic brain injury (n = 3), severe subarachnoid hemorrhage (n = 3), and intracerebral hemorrhage (n = 3). Cerebral blood flow velocities were measured by transcranial Doppler ultrasound (TCD), peripheral vasomotion by finger tip laser Doppler flowmetry (LDF), and ABP by either non-invasive continuous blood pressure recordings (Finapres method) in control subjects, or by direct radial artery recordings in comatose patients. Each recording session lasted ~ 20-30 min. Data were stored in the TCD device for offline analysis of CoV. For CoV in the cerebral B-wave frequency range there was no difference between coma patients and controls, however there was a highly significant reduction in the amplitude of peripheral B-wave LDF and ABP vasomotion (3.8 ±2.1 vs. 28.2 ± 76.7 for LDF, p < 0.00 7; and 1.2±0.7 vs. 4.6±2.8 for ABP, p < 0.001) This observation was confirmed for spontaneous cerebral and peripheral oscillations in the M-wave frequency range. The CoV reduction in peripheral LDF and ABP oscillations suggest a severe impairment of the proposed sympathetic pathway in comatose patients. The preservation of central TCD oscillations argues in favor of different pathways and/or generators of cerebral and peripheral B- and M-waves. [Neurol Res 1999; 21: 665-669]

Evaluation of noninvasive blood pressure recording by photoplethysmography in clinical studies using angiotensin challenges

Continuous noninvasive blood pressure measurement by photoplethysmography has been regularly used in the experimental paradigm of angiotensin challenges, applied to the phase I clinical testing of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists. This work aims to evaluate the performance of this measurement method, in terms of reliability, reproducibility and dependence on technical settings. Data have been gathered from 13 clinical studies on antihypertensive drugs, using the Finapres device for measuring the response to exogenous angiotensin challenges. The agreement between simultaneous recordings at different fingers and the influence of the reading method are assessed. A literature review addresses the question of the concordance between results obtained noninvasively and through arterial cannulation. The relative precision of blood pressure monitoring by photoplethysmography allows reproducible determination of angiotensin-induced blood pressure peaks (agreement limits for systolic and diastolic peaks: 12 and 6 mmHg respectively). The reading method influences the results to a similar extent. As compared with blood pressure measured intra-arterially, the difference is usually within limits of clinical acceptability. In the context of phase I studies using the angiotensin challenges methodology, the reliability and reproducibility of noninvasive blood pressure measurement appear satisfactory, despite the technical limitations of this method. The impact of selected changes in the settings and reading methods is limited.

Adverse Events in Autologous Blood Donation and Plasmapheresis – a 6-Year Analysis in 28,244 Patients with 50,542 Donations

Background: 6-year analysis of adverse events (AE) in a preoperative autologous deposit (PAD) program. Patients and Methods: This analysis was performed in 28,244 patients who underwent major bone and joint surgery from 1989 to 1994 and who took part in our PAD program. Patients were included into the PAD program if eligible for elective surgery with supposed blood loss requiring blood transfusion. Patient’s physical status was rated according to the ASA score. Blood or plasma volume donated was replaced routinely, mostly with polygeline. Monitoring during donation included ECG (lead II) and noninvasive blood pressure recording. Oxygen (2 l/min) was applied via nasal sponges. AE were rated as mild (grade I), moderate (grade II), severe (grade III), and fatal (grade IV). All AE happening in the blood bank were taken into account; additionally, all grade III and grade IV AE occurring within 24 h after PAD were considered, independent of a relationship between PAD and AE. AE were analyzed in relation to age and ASA status of the patients. Data were evaluated using descriptive statistics, chi-square test, and Spearman rank correlation; statistical significance was considered for p < 0.05. Results: 28,244 patients underwent 50,542 PAD sessions and donated a total of 132,093 autologous units. A total of 588 AE happened; i.e. in 2.08% of all participating patients and in 1.17% of all donations (not units obtained!). With increasing ASA score, i.e. with worsening of the patient’s physical status, the frequencies of mild and moderate AE decreased. 65.9% (n = 388) of all AE were considered as mild, 33.2% (n = 195) were rated as moderate, 0.51% (n = 3) were graded as severe, and 0.34% (n = 2) were fatal. No overall relation between patients’ age and frequency of AE could be demonstrated. However, patients over 70 years (21.1%) accounted for 30.7% of AE (p < 0.05). The rate of AE associated with autologous plasmapheresis was 3.4-times higher than that associated with autologous blood donation. With one exception, all severe and fatal AE were found in patients over 70 years with ASA score III and a history of cardio- or cerebrovascular diseases. All these patients had undergone autologous plasmapheresis. Conclusion: The overall frequency of AE in our PAD program was not higher than that reported for homologous programs. However, severe and fatal AE exclusively happened in patients who underwent autologous plasmapheresis. Therefore, in elderly patients and in those with concomitant cardio- or cerebrovascular diseases the indication for participation in a PAD/autologous plasmapheresis program has to be made very cautiously and by weighing pros and cons.

Psychosocial influences on blood pressure during daily life

Ambulatory blood pressure (ABP) monitoring allows frequent non-invasive blood pressure (BP) recordings in a variety of settings. Emerging evidence suggests that ABP is a better predictor of cardiovascular morbidity than clinic BP. Ambulatory blood pressure is influenced by a variety of physical, psychological and behavioral factors that comprise an individual's daily life. The present article reviews psychosocial research relating ABP to psychological factors (e.g. Type A behavior pattern, anger/hostility) and environmental influences (e.g. job strain). Psychological factors and environmental factors alone and in interaction with each other appear to substantially influence ABP. Interacting physical, psychosocial and behavioral factors that comprise daily life provide unique methodological challenges to ABP research. Methodological considerations (e.g. activity patterns, caffeine and alcohol consumption) for performing ABP research are discussed. Evidence outlined in this review suggests that psychosocial factors contribute to ABP level. To the extent that psychosocial factors contribute to ABP cardiac disease, it will be important to analyze their effects on underlying disease processes.