Epidural Blood Patches Performed with Miethke Sensor Reservoir for Continuous Intracranial Pressure Monitoring

An epidural blood patch (EBP) is a procedure performed by injecting autologous blood into a patient’s epidural space, usually at the site of a suspected CSF leak. It is typically performed in patients with characteristic postural headaches due to low intracranial pressure. We report a case of a young female with an implanted Miethke Sensor Reservoir, which was used for continuous intracranial pressure (ICP) monitoring during a two-level epidural blood patch. ICP increased only with thoracic injection, suggesting thoracic EBP may have greater efficacy than lumbar EBP in treating SIH and PDPH when the site of CSF leak is unknown.

Effects of Continuous Non-Invasive Blood Pressure Monitoring on Intraoperative Hemodynamics and Postoperative Myocardial Injury in Craniotomy:Comparison Between Groups Based on Self-Control and Propensity Score Matching

Objective:To explore the effect of continuous non-invasive blood pressure monitoring on intraoperative hemodynamics and postoperative myocardial injury in craniotomy.Methods:120 cases of elective craniotomy were divided into the self-control group(continuous non-invasive blood pressure monitoring and intermittent cuff non-invasive blood pressure monitoring,CNAP group)and propensity score matching group(only intermittent cuff non-invasive blood pressure measurement in previous craniotomy,PSM group);Goal-directed hemodynamic management in CNAP group included heart rate(HR),blood pressure(BP),stroke volume(SV),stroke variability(SVV),and systemic vascular resistance index(SVRI).The main index is to compare the troponin level within 72 hours after operation between the CNAP group and the PSM group;The secondary indicators are the comparison of the hemodynamic conditions between the CNAP group and the PSM at 10 specific time points.Results:The incidence of postoperative myocardial injury in the CNAP group was significantly lower than that in the PSM group(12%vs.30%,P=0.01);in the CNAP group hypotensive episodes(6 vs.3,P=0.01),positive balance of fluid therapy(700 vs.500 mL,P<0.001),more use of vasoactive drugs(29 vs.18,P=0.04),more stable hemodynamics medical status(P=0.03)were recorded.Conclusion:The hemodynamic management strategy based on continuous non-invasive blood pressure monitoring can reduce the incidence of myocardial injury after elective craniotomy and maintain a more stable hemodynamic state.

Ambulatory blood-pressure monitoring, antihypertensive therapy and the risk of fall injuries in elderly hypertensive patients

Background Fall injuries are common among the elderly. The aim of this study was to investigate whether blood-pressure patterns, as measured by 24-h ambulatory blood pressure monitoring （ABPM）, or intensification of antihypertensive therapy following the 24-h ABPM, may be associated with fall injuries in hypertensive elderly patients. Methods In a retrospective study, community-based elderly patients （age ≥ 70 years） who were referred to 24-h ABPM were evaluated for fall injuries within one-year post-ABPM. We compared the clinical characteristics, 24-h ABPM patterns and the intensification of hypertensive therapy following 24-h ABPM, between patients with and without a fall injury. Results Overall 1032 hypertensive elderly patients were evaluated. Fifty-five （5.3%） had a fall injury episode in the year following ABPM. Patients with a fall injury were significantly older, and with higher rates of previous falls. Lower 24-h diastolic blood-pressure （67.3 ± 7.6 vs. 70.7 ± 8.8 mmHg; P 〈 0.005） and increased pulse-pressure （74.7 ± 14.3 vs. 68.3 ± 13.7 mmHg; P 〈 0.005）, were found in the patients with a fall injury, compared to those without a fall injury. After adjustment for age, gender, diabetes mellitus and previous falls, lower diastolic blood-pressure and increased pulse-pressure were independent predictors of fall injury. Intensification of antihypertensive treatment following the 24-h ABPM was not associated with an increased rate of fall injury. Conclusions Low diastolic blood-pressure and increased pulse-pressure in 24-h ABPM were associated with an increased risk of fall injury in elderly hypertensive patients. Intensification of antihypertensive treatment following 24-h ABPM was not associated with an increased risk of fall injury.

How hypertensive patients in the rural areas use home blood pressure monitoring and its relationship with medication adherence: A primary care survey in China

Despite an increasing popularity of home blood pressure monitoring (HBPM) over the last few decades, little is known about HBPM use among hypertensive patients in the rural areas. A cross-sectional survey including 318 hypertensive patients was conducted in a rural community in Beijing, China, in 2012. Participants were mainly recruited from a community health clinic and completed the questionnaires assessing HBPM usage. Binary logistic regression models were used for the analysis of medication adherence with age, gender, level of education marital status, perceived health status, duration of hypertension, HBPM use, and frequency of performing BP measurement. Among the total population, 78 (24.5%) reported currently use of HBPM. Only 5.1% of the HBPM users cited doctor’s advice as the reason for using HBPM. Analysis of the risk factors of poor medication adherence by multivariable modeling indicated significant associations between the duration of hypertension (adjusted OR, 3.31;95% CI, 1.91-5.72;P 01), frequency of performing BP measurements (adjusted OR, 2.33;95% CI, 1.42-3.83;

A survey of recent reports on ambulatory blood pressure monitoring

This article is a review of 25 publications on ambulatory blood pressure monitoring(ABPM) and the importance of its results in everyday clinical practice. These studies, published in 2008-2011, were selected from the Scopus database, but are also available in Pubmed. They were prepared by researchers from around the world, concerned with the problems of proper control of blood pressure(BP), and of abnormalities in the circadian pattern of BP in patients with arterial hypertension, diabetes mellitus or renal failure. In the first part of this article, I analyse publications focused on some nuances in the methodology of ABPM and recommend ways to avoid some traps, related not only to the individual patient but also to the device used and the technical staff. The next section is devoted to the advantages of ABPM as a diagnostic tool which enables clinicians to learn about patients' BP during sleep, and emphasizes the practical implications of this information for so-called chronotherapy. This section also presents some new studies on the prognostic value of ABPM in patients with cardiovascular(CV) risk. Some recent articles on the results of various methods of pharmacological treatment of arterial hypertension in different agegroups are then described. The observations presented in this article may be helpful not only for researchers interested in the chronobiology of the CV system, but also for general practitioners using ABPM.

Could Ambulatory Blood Pressure Monitoring Be a Routine Investigation for Patients with Mild Cognitive Impairment?

Objectives: To study the ambulatory measured blood pressure (ABPM) profile in normotensive patients with mild cognitive impairment (MCI). Patients and Methods: The study was designed as a case control study including 50male patients with mild cognitive impairment in the age group of 30 - 50 years old. The control group included 30 volunteers with no cognitive impairment and in the same age group (30 - 50 years old) and same gender. Mini-mental estate examination, office and ABP monitoring (ABPM) and brain MRI scans were done for cases and controls. Results: Thirty patients (60%) with MCI revealed a non-dipper blood pressure pattern. Sleeping systolic blood pressure and sleeping systolic load were significantly higher in patients with MCI than in normal volunteers (p = 0.01). MRI brain showed more white matter lesions (WMLs) in patients with MCI than in normal volunteers;however, this didn’t reach significance level (p = 0.056). Conclusion: MCI in normotensive young adult patients could reflect an abnormal circadian blood pressure rhythm. Ambulatory blood pressure monitoring could be an essential investigation in young adult MCI patients.

The Clinical Application of Ambulatory Blood Pressure Monitoring in Pediatrics

Management of hypertension (HTN) largely relies on proper and accurate measurement of blood pressure (BP). Even following the criteria for HTN diagnosis defined in the Fourth report on high BP in children and adolescents, inaccurate diagnosis and misdiagnosis can occur with white coat effect and masked HTN. The use of Ambulatory Blood Pressure Monitoring (ABPM) has been increasing in pediatrics in the last 20 years. The main use of ABPM is to differentiate between sustained HTN and white coat HTN in patients who have elevated casual BP measurements and to detect masked HTN in high risk patients. ABPM is most useful in patients with casual BP within 20% of the 95th percentile for age, gender, and height. This report will highlight the use of ABPM in the evaluation of elevated BP and management of HTN in pediatrics. The discussion includes a review of various non-invasive BP measuring techniques, a description of ABPM and ABPM-unique data and diagnoses, updated ABPM clinical data more specific to pediatrics, its use in HTN clinical trials, and future outlook and direction of ABPM in pediatrics.

Individualized Isonatremic and Hyponatremic Dialysate Improves Blood Pressure in Patients with Intradialytic Hypertension: A Prospective Cross-Over Study with 24-h Ambulatory Blood Pressure Monitoring

Background. Intradialytic hypertension, a paradoxical rise in systolic blood pressure from pre- to postdialysis, is a poorly understood and difficult-to-treat phenomenon. We examined the effects of individually adjusted isonatremic and hyponatremic dialysate on intradialytic and interdialytic blood pressure in patients with intradialytic hypertension. Methods. We enrolled 11 patients with intradialytic hypertension in a prospective randomized cross-over study, with 4 treatment periods of different dialysate sodium concentrations. Period 1 (run-in) and 3 (wash-out) were standardized at 140 mEq/L;period 2 and 4 with iso- or hyponatremic sodium dialysate. Blood pressure was recorded each dialysis session, and 24-hour ambulatory blood pressure monitoring was performed at the end of each treatment period. Results. Isonatremic and hyponatremic dialysate were associated with significantly lower pre- and post-dialysis blood pressure as compared to baseline 140 mEq/L dialysate (predialysis 148.3 ± 24.7/67.7 ± 12.0 and 144.4 ± 16.5/68.8 ± 13.3 vs. 158.0 ± 18.3/75.6 ± 11.4 mmHg, resp p = 0.04 and 0.007 for systolic and p = 0.004 and 0.04 for diastolic blood pressure;postdialysis 154.2 ± 25.5/76.6 ± 14.1 and 142.5 ± 20.7/73.0 ± 12.9 vs. 159.1 ± 21.6/80.3 ± 12.1 mmHg, resp NS and p = 0.01 for systolic and NS and p = 0.04 for diastolic blood pressure). Postdialysis and 24 h systolic blood pressure tended to be lower with hyponatremic compared to isonatremic dialysate. Conclusion. Individually tailoring dialysate sodium concentration, based on the sodium set-point of each patient, resulted in a lower pre- and post-dialysis blood pressure in patients with intradialytic hypertension. 24 h blood pressure values tended to be lower as well with hyponatremic dialysate.

Clinical Study on Evaluation of Autonomic Nervous Dysfunction Based on Imaging Urodynamic Examination with Slow Filling and Synchronous Blood Pressure Monitoring in the Patients with Cervicothoracic Spinal Cord Injury

Objective: Explore the rule of autonomic nervous dysfunction in the patients with urination disorder after high level spinal cord injury, and seek a safe, objective and accurate method to evaluate autonomic nervous function. Patients and Method: 48 patients with dysuria after cervicothoracic SCI were selected. Before, during and after imaging urodynamic examination with slow filling in supine position, blood pressure and ECG were monitored simultaneously. The symptoms of sweating, shivering, headache, flushing and chills were observed and recorded. The study of the relationship among the changes of blood pressure, heart rate and urodynamic indexes and the above symptoms was analyzed. Results: They were divided into three groups: group A (no obvious abnormality), group B (hyperactivity) and group C (hypoactivity) according to their BP, HR and existing the symptoms or not. Conclusion: The incidence of autonomic dysfunction in the high level SCI patients with dysuria was very high (79.17%), most of them were hyperactivity, and a few were low function. The changes of SBP and DBP in the hypoactivity group all appeared an increasing and then declining trend, while the change of HR in the low function one was lower than normal and decreased continuously. The main inducements of AD are neurogenic detrusor overactivity, detrusor sphincter dyssynergia, elevated abdominal pressure and abnormal bladder sensitivity. The asymptomatic patients had a higher occurrence rate (43.75%). Only by imaging urodynamic examination with slow filling and synchronous blood pressure monitoring, can autonomic nervous function of the patients be evaluated safely, objectively, early and accurately.

Noncontact Monitoring of Relative Changes in Blood Pressure Using Microwave Radar Sensors

This study aims to confirm whether noncontact monitoring of relative changes in blood pressure can be estimated using microwave radar sensors. First, an equation to estimate blood pressure was derived, after which, the effectiveness of the estimation equation was confirmed using data obtained by a noncontact method while inducing variations in blood pressure. We considered that the Bramwell-Hill equation, which contains some parameters that directly indicate changes in blood pressure, would be an appropriate reference to construct an estimation equation for the noncontact method, because measurements using microwave radar sensors can measure minute scale motion on the skin surface induced by the pulsation of blood vessels. In order to estimate relative changes in blood pressure, we considered a simple equation including the pulse transit time (PTT), amplitude of signals and body dimensions as parameters. To verify the effectiveness of the equation for estimating changes in blood pressure, two experiments were conducted: a cycling task using an ergometer, which induces blood pressure fluctuations because of changes in cardiac output, and a task using the Valsalva maneuver, which induces blood pressure fluctuations because of changes in vascular resistance. The results obtained from the two experiments suggested that the proposed equation using microwave radar sensors can accurately estimate relative changes of blood pressure. In particular, relatively favorable results were obtained for the changes in blood pressure induced by the changes in cardiac volume. Although many issues remain, this method could be expected to contribute to the continuous evaluation of cardiac function while reducing the burden on patients.

Home Blood Pressure Monitoring and Its Association With Blood Pressure Control Among Hypertensive Patients With High Cardiovascular Risk in China

Objective:Home blood pressure monitoring(HBPM)is viewed as a facilitating factor in the initial diagnosis and long-term management of treated hypertension.However,evidence remains scarce about the effectiveness of HBPM use in the real world.This study aimed to examine the associations of HBPM use with blood pressure(BP)control and medication adherence.Methods:This prospective cohort study included hypertensive patients with high cardiovascular risk who were aged≥50 years.At baseline,information about types of BP monitor,frequency of HBPM,perception of anti-hypertensive treatment,and measured office BP were collected.During the 1-year follow-up(visits at 1,2,3,6,and 12 months),information on medication adherence was collected at each visit.The 2 major outcomes were BP control at baseline and medication adherence during the 1-year follow-up.A log-binomial regression model was used to examine the association between frequency of HBPM and outcomes,stratified by the perceptions of anti-hypertensive treatment.Results:A total of 5,363 hypertensive patients were included in the analysis.The age was(64.6±7.2)years,and 41.2%(2,208)were female.Of the total patients,85.9%(4,606)had a home BP monitor and 47.8%(2,564)had an incorrect perception of anti-hypertensive treatment.Overall,24.2%(1,299)of patients monitored their BP daily,37.6%(2,015)weekly,17.3%(926)monthly,and 20.9%(1,123)less than monthly.At baseline,the systolic BP and diastolic BP were(146.6±10.8)mmHg and(81.9±10.6)mmHg,respectively,and 28.5%(1,527)of patients had their BP controlled.Regardless of whether the patients had correct or incorrect perceptions of anti-hypertensive treatment,there is no significant association between HBPM frequency and BP control at baseline.During the 1-year follow-up,23.9%(1,280)of patients had non-adherence to medications at least once.In patients with an incorrect perception of anti-hypertensive treatment,those monitoring BP most frequently(daily)had the highest non-adherence rate(29.9%,175/585).Compared with those monitoring their BP less than monthly,patients who monitored their BP daily were more likely not to adhere to anti-hypertensive medications(adjusted relative risk=1.38,95%confidence interval:1.11–1.72,P=0.004).Conclusions:HBPM performance among hypertensive patients in China is,in general,sub-optimal.No association was observed between using HBPM alone and hypertension control,indicating that the effects of HBPM could be conditional.Patients’misconceptions about anti-hypertensive treatment may impair the role of BP monitoring in achieving medication adherence.Fully incorporating the correct perception of hypertension into the management of hypertensive patients is needed.

Twenty-four-hour ambulatory blood pressure changes in older patients with essential hypertension receiving monotherapy or dual combination antihypertensive drug therapy

Objective To evaluate the differences in 24-hour ambulatory blood pressure (BP) in older patients with hypertension treated with the five major classes of antihypertensive drugs,as monotherapy or dual combination therapy,to improve daytime and nighttime BP control. Methods We enrolled 1920 Chinese community-dwelling outpatients aged ≥ 60 years and compared ambulatory BP values and ambulatory BP control (24-hour BP < 130/80 mmHg;daytime mean BP < 135/85 mmHg;and nighttime mean BP < 120/70 mmHg),as well as nighttime BP dip patterns for monotherapy and dual combination therapy groups. Results Patients’ mean age was 71 years,and 59.5% of patients were women. Calcium channel blockers (CCBs) constituted the most common (60.3% of patients) monotherapy,and renin–angiotensin system (RAS) blockers combined with CCBs was the most common (56.5% of patients) dual combination therapy. Monotherapy with beta-blockers (BB) provided the best daytime BP control. The probabilities of having a nighttime dip pattern and nighttime BP control were higher in patients receiving diuretics compared with CCBs (OR = 0.52,P = 0.05 and OR = 0.41,P = 0.007,respectively). Patients receiving RAS/diuretic combination therapy had a higher probability of having controlled nighttime BP compared with those receiving RAS/CCB (OR = 0.45,P = 0.004). Compared with RAS/diuretic therapy,BB/CCB therapy had a higher probability of achieving daytime BP control (OR = 1.27,P = 0.45). Conclusions Antihypertensive monotherapy and dual combination drug therapy provided different ambulatory BP control and nighttime BP dip patterns. BB-based regimens provided lower daytime BP,whereas diuretic-based therapies provided lower nighttime BP,compared with other antihypertensive regimens.

Night time blood pressure dip

The advent of ambulatory blood pressure monitoring permitted examination of blood pressures during sleep and recognition of the associated circadian fall in pressure during this period. The fall in pressure,called the "dip",is defined as the difference between daytime mean systolic pressure and nighttime mean systolic pressure expressed as a percentage of the day value. Ten percent to 20% is considered normal. Dips less than 10%,referred to as blunted or absent,have been considered as predicting an adverse cardiovascular event. This view and the broader concept that white coat hypertension itself is a forerunner of essential hypertension is disputable. This editorial questions whether mean arterial pressures over many hours accurately represent the systolic load,whether nighttime dipping varies from measure to measure or is a fixed phenomenon,whether the abrupt morning pressure rise is a risk factor or whether none of these issues are as important as the actual night time systolic blood pressure itself. The paper discusses the difference between medicated and nonmedicated white coat hypertensives in regard to the cardiovascular risk and suggests that further work is necessary to consider whether the quality and duration of sleep are important factors.

Effects of seasonal variation on blood pressure nocturnal fall in hypertensive patients

Objective Knowledge of seasonal variation of circadian blood pressure(BP)rhythm is still limited.The present study aimed to evaluate the seasonal influences on circadian BP variation based on a telemonitoring system in a large-scale hypertensive patients.Methods Between May 2017 and March 2018,10,988 participants received ambulatory blood pressure monitoring(ABPM),of which the values were automatically and immediately transmitted through the mobile internet to a Hypertension Management Cloud Platform which stored and analyzed the data.The patients from 63 centers residing in the northern cities of China and measured in summer(June-August)and winter(December-February)were included in the analyses.

The relation between prognosis and nocturnal blood pressure variation in hypertensive patients with lacunar infarct

Objective We conducted a study using MRI and ambulatory blood pressure monitoring(ABPM) to determine whether an in-apporpriately low nocturnal blood pressure, or an excess fall in nocturnal blood pressure, might be responsible for lacunar infarct. Method ABPM and Casul blood pressure(CBP) were examined in 35 hypertentives with lacunar infarct(LI)and 33 hypertentives without lacunar infarct as control group. Results There is no significant difference of CBP between two groups. But the mean nighttime systolic blood pressure (nSBP) and diastolic blood pressure (nDBP) in patients with lacunar infarct were significantly smaller than in patients without lacunar infarct. The ratio of nSBP/dSBP and nDBP/dDBP in SI were smaller than in control group respectively. Conclusions The results indicate that an inap-propriately low nocturnal blood pressure, or an excessive fall in nocturnal blood pressure, is associated with lacunar infarct. It is necessary not only to control high blood pressure but also to pay attention to circadian changes of blood pressure during the course of anti-hypertensive treatment.

Predictive Value of Blood Pressure,Heart Rate,and Blood Pressure/Heart Rate Ratio in a Chinese Subpopulation with Vasovagal Syncope

Objective:The head-up tilt test(HUTT)is widely used but is time-consuming and not cost-effective to evaluate patients with vasovagal syncope(VVS).The present study aims to verify the hypothesis that ambulatory blood pressure(BP)monitoring(ABPM)and the simplistic tilt test may be potential alternatives to the HUTT.Methods:The study consecutively enrolled 360 patients who underwent the HUTT to evaluate VVS.BP),heart rate(HR),and BP/HR ratios derived from ABPM and the simplistic tilt test were evaluated to predict the presence,pattern,and stage of syncope during the HUTT.Results:Mixed response was the commonest pattern,and syncope occurred frequently with infusion of isoproterenol at a rate of 3μg/min.During the simplistic tilt test,the cardioinhibitory group had higher tilted BP/HR ratios than the vasodepressor group,while the vasodepressor group had a faster tilted HR and a larger HR difference than the cardioinhibitory group.The higher the BP/HR ratio in the tilted position,the higher the isoproterenol dosage needed to induce a positive response.During ABPM,BP/HR ratios were signifi cantly higher in the cardioinhibitory group than in the vasodepressor group.The higher the ABPM-derived BP,the higher the dosage of isoproterenol needed to induce syncope.There were signifi cant correlations in BP/HR ratios between ABPM and the supine position in the vasodepressor group,while signifi cant correlation was found only for the diastolic BP/HR ratio between ABPM and the tilted position in the cardioinhibitory group.The mixed pattern shared correlative features of the other two patterns.Conclusion:ABPM and the simplistic tilt test might be used as promising alternatives to the HUTT in VVS evaluation in clinical settings.

The Relationship between Abnormal Circadian Blood Pressure Rhythm and Risk of Readmission in Patients with Heart Failure with Preserved Ejection Fraction

Objective:Abnormal circadian blood pressure rhythm has been revealed to be associated with hypertensive target organ damage and cardiovascular events,but its association with readmission risk in patients with heart failure with preserved ejection fraction(HFpEF)remains unknown.We conducted a retrospective study to explore the relationship between circadian blood pressure rhythm and readmission risk in HFpEF patients.Methods:We retrospectively collected baseline and follow-up data on HFpEF patients who underwent ambulatory blood pressure monitoring(ABPM)from May 2015 to October 2019.Patient circadian blood pressure rhythms defi ned by ABPM were grouped as dipper,nondipper,or riser patterns.Univariate and multivariate linear regression analyses were performed to assess the association between circadian blood pressure rhythm and readmission risk.Results:A total of 122 patients were enrolled in this study.The mean age and ejection fraction were 69.87 years and 61.44%,respectively,with mean the N-terminal pro-B-type natriuretic peptide(NT-proBNP)level being 1048.15 pg/mL.There were signifi cant differences in the 24-hour systolic blood pressure(SBP),sleep SBP,and sleep diastolic blood pressure(DBP)among the three groups,where the 24-hour SBP,sleep SBP,and sleep DBP in the riser pattern group were markedly higher than in the dipper pattern group.Notably,serum NT-proBNP levels,the proportion of patients readmitted for heart failure and the mean number of admissions differed markedly among three groups.Instructively,multivariate linear regression analysis showed that the riser pattern was a signifi cant and independent risk factor for increased serum NT-proBNP level(β=929.16,95%confi dence interval 178.79–1679.53,P=0.016).In multivariate logistic regression analysis,the riser pattern was demonstrated to be a signifi cant risk factor for readmission(odds ratio 11.23,95%confi dence interval 2.01–62.67,P=0.006)in HFpEF patients.Conclusion:The riser blood pressure pattern is a potential risk factor for elevated serum NT-proBNP level and readmission in HFpEF patients.

Forearm Loss Caused by Automated Non-Invasive Blood Pressure Cuff Malfunction: A Hearsay Report

Failure of an automated blood pressure cuff to deflate when a patient is under general anesthesia can lead to catastrophic consequences if unnoticed for more than three hours [1]. We present this as a hearsay case in which an automated blood pressure cuff of the Spacelabs Ultraview Clinical Workstation monitor (model No. 90385) applied pressure for about five hours resulting in limb thrombosis. In order to analyze this catastrophe, simulation scenarios were tested to elucidate the possible errors and malfunctions that may have led to this injury. We present the analysis of the advantages and validity of the hearsay case report. We also include our proposed criteria that should be required when a hearsay case is considered for publication.

A Survey of the Incidence and Consequences of Invasive Blood Pressure Measuring Errors Caused by Arterial Line Occlusion

Objective: The objective is to investigate the incidence and consequences of arterial line occlusion during invasive blood pressure monitoring in the form of questionnaire survey. Methods: The questionnaires were randomly distributed to the anesthesiologists who participated the 22nd annual meeting of Chinese society of anesthesiology. The main contents of this survey included the arterial line managing status, the incidence of arterial line occlusion, the effects of arterial line occlusion on the anesthesiologists’ therapy and consequences caused by arterial line occlusion. Results: Totally 294 questionnaires were collected, in which 261 questionnaires were valid. In all respondents, 28.3% expressed that they could not flush arterial line on time, and 95.4% had experienced flushing arterial line only or sometimes or occasionally when the arterial waveform was not normal. Furthermore, 93.9% had experienced partial occlusion of the arterial line, and 79.3% had experienced complete occlusion. According to the serious recall of the respondents, the incidence of partial arterial line occlusion was 17.7% ± 22.0%, and the incidence of complete arterial line occlusion was 3.6% ± 8.1%. For all the respondents, 89.7% had experienced suspecting arterial line occlusion while real hypotension occurred, 65.1% had experienced not treating hypotension timely due to this suspicion, and 31% had experienced serious consequences caused by this suspicion. Conclusion: The incidence of arterial line occlusion is high during invasive blood pressure monitoring, which is a threat to the patients’ safety. So, intensive attention should be paid to the arterial line management.

THE CIRCADIAN ALTERATIONS OF BLOOD PRESSURE IN PATIENTS WITH SECONDARY HYPERTENSION

Objective To study the pattern of circadian blood pressure changes in patients with se-condary hypertension. Methods The 24h ambulatory blood pressure monitoring was performed in 80 patients with secondary hypertension (SH) including primary aldosteronism in 44, pheochromocytoma in 11, renovas-cular hypertension in 10, renoparenchymal hypertension in 15 and compared with 80 patients with essential hy-pertension (EH) matched by age and sex. Results The diurnal rhythm in patients with SH was different from that of patients with EU. The diurnal curves in SU and EU was overlapped in daytime and separated from each other at nighttime. The nocturnal blood pressure fall was less and average blood pressure at nighttime was higher in patients with SH than those in patients with Eli (P <0. 01). The nighttime blood pressure loading and non-dipper phenomenon were much more frequently seen in patients with SH than those in patients with Eli (P <0. 01). The nighttime blood pressure/daytime blood pressure ratio was significantly higher in patients with SH than that in patients with Eli (P <0. 01). Conclusion The non-invasive 24h ambulatory blood pressure monitoring may be a useful method in screening for