Both body and arm position significantly influence blood pressure measurement.

The position of both the body and the arm during indirect blood pressure (BP) measurement is often neglected. The aim of the present study was to test the influence of the position of the patient on BP readings: (1) sitting with the arms supported precisely at the right atrium level and (2) supine: (a) with the arms precisely at the right atrium level and (b) with the arms on the examination bed. In a first group of 57 hypertensive patients, two sessions of BP and heart rate (HR) measurements were performed in two positions: sitting and supine with the arms supported precisely at right atrium level in both positions. BP was measured simultaneously at both arms, with a Hawksley Random Zero sphygmomanometer at the right arm, and with an automated oscillometric device (Bosomat) at the left arm. BP and HR readings obtained in the two positions were then compared. In a second group of 25 normo- and hypertensive persons, two sessions of BP and HR readings were performed in supine with the arms in two different arm positions: (a) the arm placed precisely at right atrium level and (b) the other arm on the examination bed. The measurements were performed at both arms with two automated devices (Bosomat). The readings taken in the two positions were compared. Both systolic BP (SBP; by 9.5 +/- 9.0 (standard deviation, s.d.); right arm) and diastolic BP (DBP; by 4.8 +/- 6.0 mmHg; right arm) were significantly higher in the supine than in the sitting position. When the two different arm positions (body continously supine) were compared in the second part of the study, significantly higher SBP (by 4.6 +/- 6.1 mmHg) and DBP (by 3.9 +/- 2.8 mmHg) were obtained when the arm of the patient was placed on the bed (below the right atrium level), than when the arm was placed at the level of the right atrium. BP readings in sitting and supine positions are not the same. When according to guidelines the arm of the patient is meticulously placed at the right atrium level in both positions, the difference is even greater than when the arm rests on the desk or on the arm support of the chair. Moreover, in the supine position small but significant differences in BP are measured between arm on a 5 cm-high pillow and arm on the bed. In every study reporting BP values, the position of both the body and especially the arm should be precisely mentioned.

Body position and blood pressure measurement in patients with diabetes mellitus.

AIMS: World Health Organization (WHO) guidelines recommend that the blood pressure (BP) should be routinely measured in sitting or supine followed by standing position, providing that the arm of the patient is placed at the level of the right atrium in each position. The aim of our study was to test the influence of body and arm position on BP measurement in diabetic patients. METHODS: In 142 patients with diabetes mellitus the BP was measured using a semiautomatic oscillometric device (Bosomat-R): (i) after 5 min of rest sitting on a chair with one arm supported at the right atrial level and with the other arm placed on the arm support of the chair, (ii) after 5 min of rest lying on a bed with both arms placed on a bed, and (iii) after 30 s and after 2 min of standing with one arm (the same as in sitting position) supported at the right atrial level and with the other arm vertical, parallel to the body. RESULTS: Both systolic (SBP) and diastolic (DBP) blood pressures were significantly lower in sitting position with the arm at the right atrial level than in supine position (by 7.4 and 6.6 mmHg, respectively, P < 0.01). In sitting and standing positions, SBP and DBP were higher when the arm was placed either on the arm support of the chair or vertical, parallel to the body, than when the arm was supported at the level of the right atrium (by 6-10 mmHg, P < 0.001). Duration of standing did not influence the estimation of orthostatic hypotension. CONCLUSIONS: The data of this study indicate that the WHO recommendation with regard to the equivalence of sitting and supine BP readings is incorrect at least in diabetic patients, as the sitting BP is lower than the supine BP when the arm was positioned at the right atrial level. In addition, incorrect positioning of the arm in standing position results in an underestimation of prevalence of orthostatic hypotension. We conclude that during BP measurement the arm should be placed at the right atrial level regardless of the body position.

Lipoprotein (a) concentrations in patients with familial combined hyperlipidemia and hypertension.

BACKGROUND: Lipoprotein (a) (Lp(a)) is an independent risk factor for coronary heart disease (CHD), and its association with hyperlipidemia and/or hypertension greatly increases the risk of premature CHD. METHODS: The present study assessed plasma concentrations of Lp(a) in hyperlipidemic subjects from families with well-defined familial combined hyperlipidemia (FCH) (n = 262) and from patients with hypertension (n = 168), and to compare it with Lp(a) plasma levels in healthy volunteers (n = 371). Lp(a) concentrations were measured using a specific radioimmunoassay. RESULTS: The Lp(a) plasma concentrations were similar in FCH patients (median 204 mg/l, range 16-2163 mg/l) and in the control group (155, 16-1846 mg/l; P > 0.05). The Lp(a) levels in patients with hypertension (157, 10-1985 mg/l) did not differ from those of controls (P > 0.05). The Lp(a) concentrations were similar in patients with essential hypertension (EH) and normal lipid levels, and in hyperlipidemic EH patients. A tendency towards higher levels of Lp(a) was observed in patients with secondary hypertension due to renal artery stenosis (RAS) (n = 26, Lp(a) 232, 16-1110 mg/l), but this was not statistically significant. CONCLUSIONS: Plasma concentrations of Lp(a) are similar in patients with FCH, with EH, either normo- or hyperlipidemic, and with RAS, when compared with healthy controls. However, measuring the Lp(a) levels in patients with either hyperlipidemia or hypertension remains important for assessing the risk potential for severe atherosclerosis in these patients.

Arm position is important for blood pressure measurement.

AIM: To test the effect of positioning the arm on the arm-rest of a common chair, below the officially recommended right atrial level, on the blood pressure (BP) readings in a group of out-patients. PATIENTS AND METHODS: A group of 69 patients (58 hypertensives; 39 males; mean +/- s.d. age 54.1 +/- 16.0 years) participated in the present study. BP and heart rate values obtained in each of the following two positions were compared: (1) sitting with the arms supported on the arm-rests of the chair and (2) sitting with the arms supported at the level of the mid-sternum (the approximation of the right atrial level). BP was measured simultaneously at both arms, with a mercury sphygmomanometer at the right arm and with an automatic oscillometric device at the left arm. RESULTS: Both the systolic and diastolic BPs were significantly higher (P < 0.0001) when the arm was placed on the arm-rest of the chair than at the right atrial level. The same differences +/- s.d. in BP between the two positions were obtained with both measurement techniques: 9.7 +/- 9.4 mm Hg (systolic) and 10.8 +/- 5.8 mm Hg (diastolic) with the mercury sphygmomanometer and respectively 7.3 +/- 8.9 mm Hg and 8.3 +/- 6.0 mm Hg with the oscillometric device. No difference in the heart rate was found between the two positions. CONCLUSIONS: Placing the patient's arms on the arm-rest of the chair instead of at the reference right atrial level, BP measurement will result in spuriously elevated BP values. This may be of great importance for the diagnosis and the subsequent treatment decisions for patients with hypertension.

Influence of the arm position on intra-arterial blood pressure measurement.

The reference level for the measurement of blood pressure (BP) is the level of the right atrium. In practice this is regularly disregarded, as the patient's arm is usually placed lower than the right atrial level. The aim of the study was to determine the influence of first, different arm positions and second, different transducer positions on the intra-arterially (i.a.) recorded BP. In 16 healthy men (age 28.1 +/- 8.0 (s.d.) years), i.a. BP was recorded at the left arm in supine position, using a 5-7 cm long cannula. The baseline position was with the tip of the cannula placed precisely at the level of the right atrium. Subsequently, the following changes were made: 5, 10, 15 and 20 cm above and 5, 10, 15, and 20 cm below the baseline position. A 2-min rest period was allowed in each position before the BP was measured. The whole procedure was done either with the transducer connected to the arm at the place of the cannula (n = 7), or with the transducer placed next to the subject and continuously kept at the right atrial level during the BP measurement (n = 9). Simultaneously, baseline BP was measured indirectly, with a standard mercury sphygmomanometer, in the opposite arm maintained with the cubital fossa at the right atrial level during the whole procedure. This resulted in the first group of seven volunteers for both the i.a. systolic (SBP) and diastolic BP (DBP) values to significantly decrease (P < 0.001) when the arm together with the transducer were elevated above the level of the right atrium, and returned to the initial value when the arm and the transducer were placed back at the right atrial level. Intra-arterial SBP and DBP significantly (P < 0.001) increased as the arm, together with the transducer, were lowered below the right atrial level and returned to the initial value when the arm and the transducer were placed back at the right atrial level. In both directions, each 5 cm change in the arm level was accompanied by a 3-4 mm Hg change in the i.a. BP value. The baseline BP, measured sphygmomanometrically at the contralateral arm, remained constant during the whole duration of the procedure. The changes in the i.a. BP were minimal in the second group of nine subjects in which only the arm but not the transducer was placed at different levels. We conclude that small deviations in arm position above or below the 'gold standard', ie, the fossa cubiti at the right atrial level, will result in largely erroneous BP values. The correct positioning of the arm during BP measurement is therefore mandatory for the diagnosis and follow-up of hypertensive subjects.

Does it matter whether blood pressure measurements are taken with subjects sitting or supine?

BACKGROUND: Several guidelines for the management of hypertension do not give special preference to a specific position of the patient during blood pressure measurement, suggesting that blood pressure readings taken with patients sitting and with patients supine are interchangeable. OBJECTIVE: To test whether there is any difference between the blood pressure readings with patients sitting and supine. DESIGN AND METHODS: Blood pressure and heart rate were measured three times each for 245 subjects (171 hypertensives), with subjects both sitting and supine, simultaneously on both arms, with a Hawksley random-zero sphygmomanometer on the right arm and a semi-automatic oscillometric device (Bosomat) on the left arm. The sequence of the two positions was randomized. The procedure was repeated on a second occasion for 49 subjects (41 hypertensives) with the sequence of the positions reversed. Because there was no systematic difference among the three readings per position, the averages of the three blood pressure and heart rate readings with subjects sitting and supine were compared and the influences of age, body mass index, hypertension and medication on the difference were examined. RESULTS: We found no influence of the subject's body posture on the systolic blood pressure. We found a higher diastolic blood pressure [by 5.2+/-0.4 mmHg (mean+/-SEM), P< 0.001 with Hawksley random-zero sphygmomanometer] and a greater heart rate [by 1.5+/-0.3 beats/min (mean+/-SEM), P< 0.001] with subjects sitting. The sitting minus supine differences for diastolic blood pressure and heart rate decreased significantly with increasing age (P< 0.001). We found no effect of body mass index, hypertension and medication on the sitting - supine differences. CONCLUSIONS: The subject's body posture influenced especially the diastolic blood pressure and heart rate, both of them being significantly higher with patients sitting rather than supine. This effect decreased with age. Thus, for indirect blood pressure measurement, diastolic blood pressure values obtained with subjects sitting and supine cannot automatically be regarded as equivalent.

The role of hyperuricemia in the increased cytokine production after lipopolysaccharide challenge in neutropenic mice.

Patients with severe granulocytopenia are more susceptible to severe infections and sepsis. Proinflammatory cytokines such as tumor necrosis factor-alpha (TNF), interleukin-1 alpha (IL-1 alpha), and IL-1 beta play an important role in the pathophysiology of sepsis. The profile of these proinflammatory cytokines after lipopolysaccharide (LPS) challenge in cyclophosphamide-induced neutropenic mice was assessed, and possible mechanisms responsible for the modified cytokine production were studied. After LPS, both circulating concentrations of TNF and IL-1 alpha in neutropenic mice were 50% to 200% higher than those of controls, whereas IL-1 beta concentrations were not modified. The kinetics of cytokine production were similar in neutropenic and control animals. The susceptibility of neutropenic mice to an LPS challenge was increased. The observed overproduction of TNF and IL-1 alpha was not due to a direct effect of cyclophosphamide treatment. Because circulating concentrations of uric acid were increased in the neutropenic mice, the effect of hypouricemic treatment with allopurinol and sodium bicarbonate was investigated; such treatment in neutropenic mice challenged with LPS was followed by an improved survival and a reduced proinflammatory cytokine production towards the concentrations in control mice. Hyperuricemia induced by repeated administrations of uric acid in normal mice led to an increased TNF production after LPS. In conclusion, neutropenic mice respond with enhanced cytokine production and increased susceptibility to an LPS challenge, and hyperuricemia probably plays an important role in this phenomenon.