Right- and left-arm blood pressure discrepancies in vascular surgery patients

Inter-Arm Blood Pressure Difference an Indicator of Coronary Artery Disease

INTRODUCTION

Considering the scarcity of the literature on the association between inter-arms blood pressure difference (IABPD) and coronary artery disease (CAD).

AIM

We performed this study to investigate the prevalence of IABPD within the Jordanian population and to assess if it has an association with CAD.

METHODS

We sampled patients visiting the cardiology clinics at the Jordan University Hospital between October, 2019 and October 2021 into two groups. Participants were divided into two groups; patients with severe CAD and control group who had no evidence of CAD.

RESULTS

We measured the blood pressure for a total of 520 patients. Of the included patients, 289 (55.6 %) had CAD while 231 (44.4%) were labeled as controls who were normal. A total of 221 (42.5%) participants had systolic IABPD above 10 mmHg, while 140 (26.9%) had a diastolic IABPD above 10 mmHg. Univariate analysis demonstrated that patients with CAD were significantly more likely to be older (p < 0.001), of the male gender (p < 0.001), hypertensive (p < 0.001), and having dyslipidemia (p < 0.001). Moreover, they had significantly higher IABPD differences in terms of both systolic and diastolic blood pressure (p < 0.001 and p = 0.022, respectively). Multivariate analysis showed that CAD was a positive predictor of abnormal systolic IABPD.

CONCLUSION

In our study, elevated systolic IABPD was associated with a higher prevalence of severe CAD. Patients with abnormal IABPD might be subjected to more specialist investigation as IABPD consistently predicts coronary artery disease, peripheral arterial disease or other vasculopathy throughout the literature.

Moderate to severe obstructive sleep apnea is independently associated with inter-arm systolic blood pressure difference: Tokyo Sleep Heart Study

OBJECTIVE

Obstructive sleep apnea (OSA) is recognized as an independent risk factor for cardiovascular disease. On the other hand, inter-arm systolic blood pressure difference (IAD), inter-ankle systolic blood pressure difference (IAND), and ankle-brachial index (ABI) are all known predictors of cardiovascular events. The aim of the present study was to investigate the association between OSA and four-limb blood pressure differences.

METHODS

We conducted this cross-sectional study in a large sleep cohort from Tokyo Sleep Heart Study. In 2643 consecutive patients who visited our sleep clinic for polysomnography between 2005 and 2017, all the patients underwent blood pressure measurement simultaneously in all the four limbs by oscillometric methods.

RESULTS

The prevalence rate of IAD ≥10 mmHg was significantly higher in the moderate OSA (15 ≤ apnea-hypopnea index [AHI] < 30) group (4.2%) and severe OSA (AHI ≥ 30) group (4.6%) than that in the no/mild (AHI < 15) OSA group (1.4%). Multivariate logistic regression analysis also identified moderate to severe OSA as being significantly associated with IAD ≥10 mmHg, even after adjustments for confounding variables (moderate OSA: odds ratio [OR], 4.869; 95% confidence interval [CI], 1.080-21.956; P = 0.039; severe OSA: OR, 5.301; 95% CI, 1.226-22.924; P = 0.026). However, there were no significant associations of the OSA severity with IAND ≥15 mmHg or ABI <0.9.

CONCLUSIONS

Moderate to severe OSA was independently associated with the IAD, not but with the IAND or ABI.

Inter-arm blood pressure difference and mortality: a cohort study in an asymptomatic primary care population at elevated cardiovascular risk

BACKGROUND

Differences in blood pressure between arms are associated with increased cardiovascular mortality in cohorts with established vascular disease or substantially elevated cardiovascular risk.

AIM

To explore the association of inter-arm difference (IAD) with mortality in a community-dwelling cohort that is free of cardiovascular disease.

DESIGN AND SETTING

Cohort analysis of a randomised controlled trial in central Scotland, from April 1998 to October 2008.

METHOD

Volunteers from Lanarkshire, Glasgow, and Edinburgh, free of pre-existing vascular disease and with an ankle-brachial index ≤0.95, had systolic blood pressure measured in both arms at recruitment. Inter-arm blood pressure differences were calculated and examined for cross-sectional associations and differences in prospective survival. Outcome measures were cardiovascular events and all-cause mortality during mean follow-up of 8.2 years.

RESULTS

Based on a single pair of measurements, 60% of 3350 participants had a systolic IAD ≥5 mmHg and 38% ≥10 mmHg. An IAD ≥5 mmHg was associated with increased cardiovascular mortality (adjusted hazard ratio [HR] 1.91, 95% confidence interval [CI] = 1.19 to 3.07) and all-cause mortality (adjusted HR 1.44, 95% CI = 1.15 to 1.79). Within the subgroup of 764 participants who had hypertension, IADs of ≥5 mmHg or ≥10 mmHg were associated with both cardiovascular mortality (adjusted HR 2.63, 95% CI = 0.97 to 7.02, and adjusted HR 2.96, 95% CI = 1.27 to 6.88, respectively) and all-cause mortality (adjusted HR 1.67, 95% CI = 1.05 to 2.66, and adjusted HR 1.63, 95% CI = 1.06 to 2.50, respectively). IADs ≥15 mmHg were not associated with survival differences in this population.

CONCLUSION

Systolic IADs in blood pressure are associated with increased risk of cardiovascular events, including mortality, in a large cohort of people free of pre-existing vascular disease.

[The interarm blood pressure difference in the critically ill patient]

BACKGROUND AND OBJECTIVE

To evaluate the prevalence of a difference in systolic blood pressure (SBPd) ≥ 10 mmHg between arms in patients admitted in a Critical Care Unit and to examine the clinical characteristics associated with such blood pressure difference.

METHODS

Observational cross-sectional study. Two blood pressure measurements in each arm were carried out at unit admission. The firstly measured arm was chosen at random.

RESULTS

One-hundred and sixty-eight patients were studied, with a mean age of 61 (SD=16), 67.3% male and 45% with a previous hypertension diagnosis. On admission, 27.4% presented SBPd ≥ 10 mmHg. Among them, 54% had higher SBP in the right arm and 46% in the left one. A SBPd ≥ 10 mmHg was associated with a previous hypertension diagnosis (67.4 versus 36.9%; P<.001) and with reduced consciousness (76.1 versus 52.5%; P=.006).

CONCLUSIONS

Over a quarter of critically ill patients have a SBPd ≥ 10 mmHg between arms. This feature is associated with a previous hypertension diagnosis and reduced consciousness. It should be assessed in the future if the choice of a control arm would help improve patient's care as it would become a more accurate guide for hemodynamic management.

A difference in systolic blood pressure between arms and between lower limbs is a novel risk marker for diabetic nephropathy in patients with type 2 diabetes

Recent studies have demonstrated that a difference in systolic blood pressure (SBP) between arms is associated with both vascular disease and mortality. The aim of this study was to investigate the relationship between a difference in SBP between arms and between lower limbs and the degree of albuminuria, which is an established marker for cardiovascular disease and diabetic nephropathy in patients with Type 2 diabetes. We measured blood pressure in the arms and lower limbs of 314 consecutive patients with Type 2 diabetes, and we calculated a difference in SBP between arms and between lower limbs. We then evaluated the relationship of the difference in SBP between arms and between lower limbs to the degree of urinary albumin excretion (UAE). The average difference in SBP between arms and between lower limbs was 3.52±3.94 and 9.66±14.1 mm Hg, respectively. Multiple regression analyses demonstrated that a difference in SBP between arms (β=0.172, P=0.0239) and between lower limbs (β=0.238, P=0.0033) independently correlated with the logarithm of the UAE. Multiple logistic regression analyses showed that a difference in SBP of 10 mm Hg between arms (odds ratio 12.23 (95% CI 1.130-132.35), P<0.0393) and a difference in SBP of 15 mm Hg between lower limbs (odds ratio 4.291 (95% CI 1.403-13.123), P<0.0106) correlated with the risk of albuminuria. A difference in SBP between arms and between lower limbs, therefore, could be a novel risk marker for diabetic nephropathy in patients with Type 2 diabetes.

The difference in blood pressure readings between arms and survival: primary care cohort study

OBJECTIVE

To determine whether a difference in systolic blood pressure readings between arms can predict a reduced event free survival after 10 years.

DESIGN

Cohort study.

SETTING

Rural general practice in Devon, United Kingdom.

PARTICIPANTS

230 people receiving treatment for hypertension in primary care.

INTERVENTION

Bilateral blood pressure measurements recorded at three successive surgery attendances.

MAIN OUTCOME MEASURES

Cardiovascular events and deaths from all causes during a median follow-up of 9.8 years.

RESULTS

At recruitment 24% (55/230) of participants had a mean interarm difference in systolic blood pressure of 10 mm Hg or more and 9% (21/230) of 15 mm Hg or more; these differences were associated with an increased risk of all cause mortality (adjusted hazard ratio 3.6, 95% confidence interval 2.0 to 6.5 and 3.1, 1.6 to 6.0, respectively). The risk of death was also increased in 183 participants without pre-existing cardiovascular disease with an interarm difference in systolic blood pressure of 10 mm Hg or more or 15 mm Hg or more (2.6, 1.4 to 4.8 and 2.7, 1.3 to 5.4). An interarm difference in diastolic blood pressure of 10 mm Hg or more was weakly associated with an increased risk of cardiovascular events or death.

CONCLUSIONS

Differences in systolic blood pressure between arms can predict an increased risk of cardiovascular events and all cause mortality over 10 years in people with hypertension. This difference could be a valuable indicator of increased cardiovascular risk. Bilateral blood pressure measurements should become a routine part of cardiovascular assessment in primary care.

Association of a difference in systolic blood pressure between arms with vascular disease and mortality: a systematic review and meta-analysis

BACKGROUND

Differences in systolic blood pressure (SBP) of 10 mm Hg or more or 15 mm Hg or more between arms have been associated with peripheral vascular disease and attributed to subclavian stenosis. We investigated whether an association exists between this difference and central or peripheral vascular disease, and mortality.

METHODS

We searched Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane, and Medline In Process databases for studies published before July, 2011, showing differences in SBP between arms, with data for subclavian stenosis, peripheral vascular disease, cerebrovascular disease, cardiovascular disease, or survival. We used random effects meta-analysis to combine estimates of the association between differences in SBP between arms and each outcome.

FINDINGS

We identified 28 eligible studies for review, 20 of which were included in our meta-analyses. In five invasive studies using angiography, mean difference in SBP between arms was 36·9 mm Hg (95% CI 35·4-38·4) for proven subclavian stenosis (>50% occlusion), and a difference of 10 mm Hg or more was strongly associated with subclavian stenosis (risk ratio [RR] 8·8, 95% CI 3·6-21·2). In non-invasive studies, pooled findings showed that a difference of 15 mm Hg or more was associated with peripheral vascular disease (nine cohorts; RR 2·5, 95% CI 1·6-3·8; sensitivity 15%, 9-23; specificity 96%, 94-98); pre-existing cerebrovascular disease (five cohorts; RR 1·6, 1·1-2·4; sensitivity 8%, 2-26; specificity 93%, 86-97); and increased cardiovascular mortality (four cohorts; hazard ratio [HR] 1·7, 95% CI 1·1-2·5) and all-cause mortality (HR 1·6, 1·1-2·3). A difference of 10 mm Hg or higher was associated with peripheral vascular disease (five studies; RR 2·4, 1·5-3·9; sensitivity 32%, 23-41; specificity 91%, 86-94).

INTERPRETATION

A difference in SBP of 10 mm Hg or more, or of 15 mm Hg or more, between arms might help to identify patients who need further vascular assessment. A difference of 15 mm Hg or more could be a useful indicator of risk of vascular disease and death.

FUNDING

Royal College of General Practitioners, South West GP Trust, and Peninsula Collaboration for Leadership in Applied Health Research and Care.

The epidemiology of subclavian stenosis and its association with markers of subclinical atherosclerosis: the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Recent studies indicate that subclavian stenosis (SS), diagnosed by a large systolic blood pressure difference (SBPD) between the right and left brachial arteries, is associated with cardiovascular disease (CVD) risk factors and outcomes. We sought to describe the epidemiology of SS and determine its association with markers of subclinical CVD in the baseline cohort of the Multi-Ethnic Study of Atherosclerosis.

METHODS

We defined SS by an absolute SBPD>or=15 mmHg. Peripheral artery disease (PAD) was defined by an ankle-brachial index<or=0.90. The coronary artery calcium score (CAC) and the common carotid artery intima-media thickness (CCA-IMT) were measured by computed tomography and B-mode ultrasound, respectively. Odds ratios for the associations of SS with risk factors and subclinical disease were estimated using logistic regression.

RESULTS

Of 6743 subjects studied, 307 participants (4.6%) had SS, with a higher prevalence in women (5.1%) than men (3.9%), and in African Americans (7.4%) and non-Hispanic whites (5.1%) than Hispanic (1.9%) or Chinese (1.0%) participants (p<0.01). In a model including age, gender, ethnicity, traditional and novel CVD risk factors, significant associations with SS were observed for C-reactive protein (highest vs. three lower quartiles: OR=1.41; 95%CI: 1.06-1.87) and brachial artery pulse pressure (OR=1.12/10 mmHg; 95%CI: 1.03-1.21). Adjusted for age, gender, ethnicity, traditional and novel CVD risk factors, SS was significantly associated with PAD (OR=2.35; 1.55-3.56), with CCA-IMT (highest vs. the lower three quartiles: OR=1.32; 1.00-1.75), and high CAC (score>100 vs. score=0; OR=1.43; 1.03-2.01).

CONCLUSIONS

The subclavian stenosis is positively associated with other markers of subclinical atherosclerosis.

Inter-arm blood pressure differences in pregnant women

OBJECTIVE

To determine the prevalence of blood pressure inter-arm difference (IAD) in early pregnancy and to investigate its possible association with maternal characteristics.

DESIGN

A cross-sectional observational study.

SETTING

Routine antenatal visit in a university hospital.

POPULATION

A total of 5435 pregnant women at 11-14 weeks of gestation.

METHODS

Blood pressure was taken from both arms simultaneously with a validated automated device.

MAIN OUTCOME MEASURES

The presence of inter-arm blood pressure difference of 10 mmHg or more.

RESULTS

The IAD in systolic and diastolic blood pressure was 10 mmHg or more in 8.3 and 2.3% of the women, respectively. Systolic IAD was found to be significantly related to systolic blood pressure and pulse pressure, and diastolic IAD was found to be significantly related to maternal age, diastolic blood pressure and pulse pressure. The systolic and diastolic IAD were higher in the hypertensive group compared with the normotensive group and absolute IAD increased with increasing blood pressure. About 31.0 and 23.9% of cases of hypertension would have been underreported if the left arm and the right arm were used, respectively, in measuring the blood pressure.

CONCLUSIONS

There is a blood pressure IAD in a significant proportion of the pregnant population, and its prevalence increases with increasing blood pressure. By measuring blood pressure only on one arm, there is a one in three chance of underreporting hypertension. Therefore, it would be prudent that during the booking visit blood pressure should be taken in both arms and thus provide guidance for subsequent blood pressure measurements during the course of pregnancy.

Interarm blood pressure differences in the women's interagency HIV study

Hypertension has been reported in 8-32% of HIV-infected individuals. Large interarm blood pressure differences (IABPD) may cause misclassification of blood pressure (BP) status. The objectives of this study were to determine the magnitude and factors associated with IABPD in HIV-infected women and uninfected controls. Using automated devices, two BP recordings were measured and averaged from each arm in Brooklyn enrollees of the Women's Interagency HIV Study. Absolute IABPD was calculated for each patient. Among 335 subjects, 238 were HIV infected and 97 were uninfected. Mean systolic and diastolic IABPD were 6 +/- 5 mm Hg and 4 +/- 3 mm Hg, respectively. Twenty-six percent of subjects had systolic IABPD >10 mm Hg and 6% had systolic IABPD >20 mm Hg. Fifteen percent of subjects had diastolic IABPD >10 mm Hg. Interarm BP differences were not associated with HIV serostatus, CD4(+) cell count, and use of highly active antiretroviral therapy. Systolic IABPD >20 mm Hg was associated with obesity (ORadj 5.37, 95% CI 1.47, 19.65), and LDL cholesterol above 160 (ORadj 9.12, 95% CI 2.53, 32.88). Right arm BP measurement resulted in 10% of subjects with high/uncontrolled BP. Bilateral arm BP measurement increased the yield to 15% (p < 0.001). In conclusion, systolic and diastolic IABPD are common and appear to be of clinically important magnitude. Systolic IABPD are related to cardiovascular risk factors but not to HIV-related factors. Bilateral BP determination is important to detect and manage hypertension as well as for accurate cardiovascular risk assessment.

Prevalence and clinical implications of the inter-arm blood pressure difference: a systematic review

A blood pressure (BP) difference between arms was first reported over 100 years ago. Knowledge of its prevalence and relevance to the accurate measurement of BP remains poor. Current hypertension guidelines do not emphasise it. The objectives of this study were to establish the best estimate of prevalence of the inter-arm difference (IAD) in the population, to consider its implications for accurate BP measurement and treatment, and to discuss its aetiology and potential as a risk marker for cardiovascular disease. Systematic literature review was carried out. The data sources were Medline EMBASE and CINAHL databases, and Index of Theses. Studies reporting prevalence rates of IAD were retrieved and considered for inclusion against explicit methodological criteria. Point prevalence rates were extracted and weighted mean prevalence rates calculated. The main outcome measures were weighted mean prevalences of systolic IAD > or =10 and > or =20 mm Hg and of diastolic IAD > or =10 mm Hg. Thirty-one studies were identified. Most had methodological weaknesses; only four met the inclusion criteria. Pooled prevalences of the IAD from these four studies were 19.6% systolic > or =10 mm Hg (95% CI 18.0-21.3%), 4.2% systolic > or =20 mm Hg (95% CI 3.4-5.1%) and 8.1% diastolic > or =10 mm Hg (95%CI 6.9-9.2%). In conclusion, an IAD is present in a substantial number of patients and should be looked for whenever diagnosis and treatment depend on accurate measurements of BP. The importance of an IAD should be better emphasised in current hypertension management guidelines. There is evidence associating an IAD with peripheral vascular disease, raising the possibility that its presence may predict cardiovascular events.

The unilateral measurement of blood pressure may mask the diagnosis or delay the effective treatment of hypertension

Several studies have indicated the presence of significant interarm blood pressure (BP) differences; this could result in misclassification of BP status. Nevertheless, the findings of these studies were not consistent. This prospective, observational study investigated the presence and magnitude of interarm BP differences and determined the influence of age, gender, arm circumference, smoking, being hypertensive or diabetic, or having a previous history of cardiovascular disease in these differences. The study included 384 subjects, who were patients, ward visitors, and members of the nursing staff of this Department. BP measurements were recorded simultaneously in both arms by using 2 validated, fully automated oscillometric electronic devices. There were significant differences between the right arm and left arm systolic BP (p < 0.0005), between right arm and left arm diastolic BP (p < 0.05), and between right arm and left arm pulse pressure (p = 0.006). The mean interarm differences in systolic and diastolic BP measurements were 1.2 +/-5.0 mm Hg and 0.4 +/-4.2 mm Hg, respectively. There were 13 subjects (3.4%) and 4 subjects (1.04%) with an interarm systolic and diastolic BP difference of > 10 mm Hg, respectively, and a single patient with both interarm systolic and diastolic BP differences of > 10 mm Hg (0.26%). None of the studied demographic or clinical characteristics was a significant predictor of interarm systolic and diastolic BP differences. The authors conclude that significant interarm systolic and diastolic BP differences are frequently present. Therefore, the unilateral measurement of BP may mask the diagnosis or delay the effective treatment of hypertension. It is thus recommended that BP should be simultaneously measured in both arms at the initial consultation and the higher of the 2 readings should be used to guide further management decisions.

The Validity, Reliability, Reproducibility and Extended Utility of Ankle to Brachial Pressure Index in Current Vascular Surgical Practice

BACKGROUND

Despite the increasing sophistication of vascular surgical practice, more than three decades after its introduction to clinical practice, the ankle to brachial pressure index (ABPI) remains the cornerstone of non-invasive assessment of the patient with symptomatic peripheral arterial disease (PAD).

AIM

To summarise what is known about ABPI and critically appraise its validity, reliability, reproducibility and extended utility.

METHODS

A MEDLINE (1966-2004) and Cochrane library search for articles relating to measurement of ABPI was undertaken; see text for further details.

RESULTS

There is considerable disagreement as to how ABPI should be measured. Furthermore, various factors, including the type of equipment used, and the experience of the operator, can result in significant inter- and intra-observer error. As such, care must be taken when interpreting data in the literature. ABPI is valuable in the assessment of patients with atypical symptoms, venous leg ulcers and after vascular and endovascular interventions. However, absolute pressures are probably more valuable in patients with critical limb ischaemia. ABPI is also useful in subjects with asymptomatic PAD where it correlates well with, and may be used in screening studies to quantify, cardiovascular risk.

CONCLUSIONS

While its apparent simplicity can beguile the unwary, ABPI will continue to have a key role in the assessment of symptomatic PAD. ABPI is also likely to have extended utility in health screening and institution of best medical therapy in asymptomatic subjects.

Subclavian Artery Stenosis: Prevalence, Risk Factors, and Association With Cardiovascular Diseases

OBJECTIVES

The objective was to assess the prevalence of subclavian artery stenosis (SS) in four cohorts (two free-living and two clinical populations) and determine both risk factors for this condition and the association with other cardiovascular conditions.

BACKGROUND

The prevalence of SS in the general population is unknown, and its association with risk factors and other cardiovascular diseases is not well-established.

METHODS

A total of 4,223 subjects (2,975 from two free-living cohorts and 1,248 from two clinical cohorts) were included in this cross-sectional analysis. Subclavian artery stenosis was defined as > or =15 mm Hg interarm pressure difference.

RESULTS

The prevalence of SS was 1.9% in the free-living cohorts and 7.1% in the clinical cohorts; SS was significantly (p < 0.05) associated with past smoking (odds ratio [OR] = 1.80), current smoking (OR = 2.61), and higher levels of systolic blood pressure (OR = 1.90 per 20 mm Hg). Higher levels of high-density lipoprotein (HDL) cholesterol were inversely and significantly associated with SS (OR = 0.87 per 10 mg/dl). In regression analyses relating SS to other cardiovascular diseases, the only significant finding was with peripheral arterial disease (PAD) (OR = 5.11, p < 0.001).

CONCLUSIONS

Significant SS is present in approximately 2% of the free-living population and 7% of the clinical population. Additionally, SS is correlated with current and past smoking histories, systolic blood pressure, HDL levels (inversely), and the presence of PAD. These findings suggest that bilateral brachial blood pressure measurements should routinely be performed in patients with an elevated risk profile, both to screen for SS, and to avoid missing a hypertension or PAD diagnosis because of unilateral pressure measurement in an obstructed arm.

Monitoring arterial blood pressure during whole body hyperthermia

BACKGROUND

For monitoring of arterial blood pressure (ABP) during whole body hyperthermia (WBH) different methods have been recommended. This investigation was performed to evaluate the agreement of invasive measurements at various sites, and to compare invasive and non-invasive methods of ABP monitoring under conditions of a heat-induced extreme vasodilation.

METHODS

In 19 patients, 48 treatments with WBH were performed. Measurements of ABP in the radial and femoral artery by oscillometry and by sphygmomanometry were taken at four temperature levels during WBH (37, 40, 41.8 and 39 degrees C).

RESULTS

Significant differences were observed between invasive and non-invasive methods for systolic ABP, with higher values for non-invasive measurements. When compared with both invasive measurements for diastolic blood pressures, sphygmomanometry gave higher values and oscillometry gave lower values. Sphygmomanometry also showed higher values for mean ABP compared with all other techniques, while measurements in radial and femoral artery and by oscillometry only differed by approximately 5 mmHg.

CONCLUSION

The mean arterial pressure and not the systolic and/or diastolic pressure should guide hemodynamic management during WBH. The sphygmomanometric technique is not recommended for use during hyperthermia.

Complete Myocardial Revascularization in Severe Arteriopathy

Multivessel coronary revascularization was successfully performed in a 75-year-old man with severe atherosclerosis of the ascending aorta and aortic arch, significant stenoses in the right subclavian, innominate, and aortoiliac arteries, renal impairment, and conduit shortage, by combining the beating-heart approach with aorta-sparing pedicled arterial and venous grafts. No postoperative complications were encountered.

A study of inter-arm blood pressure differences in primary care

OBJECTIVES

To investigate whether there are inter-arm blood pressure differences that are of clinical importance to general practice.

DESIGN AND SETTING

Pragmatic study with randomised order of use of left or right arm carried out in routine surgeries in an inner city and suburban general practice.

SUBJECTS

There were 237 patients presenting opportunistically for blood pressure measurement to a nurse or general practitioner.

MAIN OUTCOME MEASURES

95% limits of agreement between measurements on the left and right arm and bias between arms.

RESULTS

Large inter-arm blood pressure differences exist reflected in wide 95% limits of agreement; -16 mm Hg to 24 mm Hg for the right minus the left arm diastolic blood pressure. There is a small but statistically significant bias to the right arm blood pressure measuring higher than the left (3.7 mm Hg diastolic, 2.4 to 5 mm Hg 95% confidence intervals). An interarm difference of 10 mm Hg or greater for diastolic blood pressure occurred in 40% of subjects and a difference of 20 mm Hg or more for systolic blood pressure occurred in 23% of subjects.

CONCLUSIONS

In a primary care setting blood pressure should be measured routinely in both arms. If one arm is to be preferred for pragmatic clinical purposes, then this should be the right arm.

Radial artery pressure monitoring underestimates central arterial pressure during vasopressor therapy in critically ill surgical patients

OBJECTIVES

Radial artery pressure is known to differ from central arterial pressure in normal patients (distal pulse amplification) and in the early postcardiopulmonary bypass period. The adequacy of the radial artery as a site for blood pressure monitoring in critically ill patients receiving high-dose vasopressors has not been carefully examined.

DESIGN

Prospective observational study comparing simultaneous intra-arterial measurements of radial (peripheral) and femoral artery (central) pressures.

SETTING

Clinical investigation in a university-based surgical intensive care unit.

PATIENTS

Fourteen critically ill patients with presumed sepsis who received norepinephrine infusions at a rate of > or =5 microg/min.

INTERVENTIONS

All patients were managed in accordance with our standard practice for presumed sepsis, which consisted of intravascular volume repletion followed by vasopressor administration titrated to a mean arterial pressure of > or =60 mm Hg.

MEASUREMENTS AND MAIN RESULTS

Systolic and mean arterial pressures were significantly higher when measured from the femoral vs. radial site (p < .005). The higher mean arterial pressures enabled an immediate reduction in norepinephrine infusions in 11 of the 14 patients. No change in cardiac output or pulmonary artery occlusion pressure was noted after dose reduction. In the two patients in whom simultaneous recordings were made after discontinuation of norepinephrine infusions, equalization of mean arterial pressures was observed.

CONCLUSIONS

Radial artery pressure underestimates central pressure in hypotensive septic patients receiving high-dose vasopressor therapy. Clinical management, based on radial pressures, may lead to excessive vasopressor administration. Awareness of this phenomena may help minimize adverse effects of these potent agents by enabling dosage reduction.

What's new in monitoring the coronary surgery patient?

Monitoring has been extensively reviewed in most textbooks of cardiothoracic surgery and anaesthesia, particularly in the recent textbooks on monitoring edited by Carol L Lake 1 and Casey D Blitt 2 and in the Journal of Clinical Monitoring. Although monitoring properly includes both pre- and postoperative periods, this review will concentrate exclusively on the operative period. I will also concentrate on new approaches or information which relate to more traditional approaches to monitoring. The emphasis in this review will not be on what we can monitor, but rather on what we should monitor. In this regard, I will analyse accuracy and identify sources of error and try to answer the following questions. Does the device or parameter measure (monitor) what we want to know? Does it improve patient outcome and safety? Is it cost-effective? Unfortunately, data are not always available to answer all these questions at present, but hopefully the discussions will make us aware of what we do and do not know, and what we should look for in the near future.