Auscultatory measurement of arterial pressure during anaesthesia: a reassessment of Korotkoff sounds

The accuracy of the indirect auscultatory method, using Korotkoff sounds for determination of arterial pressures, was investigated by comparison with direct intra-arterial measurements. Eight hundred and sixty-three comparisons were made in 25 patients aged between 27 and 75 years over blood pressures ranging from 59 to 235 mmHg for systolic and 28 to 145 mmHg for diastolic. The regression equation for all systolic pressure measurements was y = 13.9 + 0.81x, and for all diastolic pressure measurements was y = 21.4 + 0.71x. Although there was a significant (P less than 0.001) correlation coefficient between direct and indirect measurements for both systolic (r = 0.93) and diastolic pressures (r = 0.79), the 95% confidence limits (+/- 22 mmHg for systolic and +/- 19 mmHg for diastolic) were very wide, reflecting the influences of observer variation and other sources of error.     

Ambulatory blood pressure monitoring in patients receiving long, slow home haemodialysis.

BACKGROUND: Good blood pressure (BP) control has been reported previously in haemodialysis (HD) patients receiving 8-h dialysis sessions. Home HD allows patients to dialyze for long periods, but there are few data on the BP control achieved by these patients. We studied BP control, using ambulatory blood pressure monitoring (ABPM), in our home-HD patients who were receiving long-hours dialysis. METHODS: Twenty-four patients aged 52.7+/-11 years underwent ABPM. They had been on home HD for 52.9+/-39 months and dialysed for 7.2+/-1.1 h thrice weekly. Two patients were taking antihypertensive drugs. Historical data on BP and weight gains were obtained from the patients' own records. Left ventricular (LV) mass was assessed by echocardiography and total body water (TBW) by bioelectrical impedance. RESULTS: The mean 24-h BP was 129+/-17 mmHg (systolic) and 83+/-14 mmHg (diastolic). The daytime BP was 131+/-17 mmHg (systolic) and 84+/-14 mmHg (diastolic), while the night-time BP was 126+/-22 mmHg (systolic) and 81+/-17 mmHg (diastolic). Six patients (25%) had a normal circadian BP rhythm, but the rest showed a subnormal fall or an increase in BP at night. Mean 24-h BP did not correlate significantly with time on dialysis, dialysis session length, Kt/V, haemoglobin, interdialytic weight gain, or TBW. Twenty-one patients (87%) had LV hypertrophy and 16 of these had diastolic dysfunction. LV mass index was inversely correlated with nocturnal BP fall (r=-0.54, P=0.03). Non-dippers had been treated longer than dippers (29 vs 59.2 months, P=0.03) but they were similar in respect to age, dialysis session length or Hb concentration. CONCLUSIONS: Long, slow haemodialysis at home provides satisfactory daytime BP control in the majority of patients without the need for antihypertensive drugs but abnormal circadian BP rhythm and LV hypertrophy remain common.     

An evaluation of non-invasive blood pressure (NIBP) monitoring on the wrist: comparison with upper arm NIBP measurement

The arm is the traditional site for application of an oscillometric non-invasive blood pressure (NIBP) cuff This study, which compares upper arm NIBP to wrist NIBP, involved 510 same arm sequential paired blood pressure (BP) measurements in 85 volunteers. Wrist NIBP consistently overestimated mean arterial, systolic and diastolic pressure by approximately 10 mmHg. Ninety per cent of the mean arterial pressure differences at the wrist were within a range of +/- 9 mmHg around a mean difference of 10.6 mmHg. The systolic pressure difference was 11.2 mmHg with 90% of differences between +/- 12 mmHg. The diastolic pressure difference was 10.2 mmHg with 90% of differences between +/- 9 mmHg. With the device used and within the normal blood pressure range, compensation can be performed by subtracting 10 mmHg from the measured values or simply by elevating the wrist about 15 cm and taking the BP at face value. Wrist NIBP may be a viable clinical alternative in situations where difficulty occurs with upper arm NIBP measurement.     

Evaluation of a new blood pressure cuff for patients with large and normal arm circumferences

A new multisize blood pressure cuff (TriCuff; Inmed) which automatically adjusts to fit any size arm was tested against the routinely used 12 x 23 cm cuff in patients with an arm circumference less than 33 cm (group A = 30) and against the 15 x 33 cm cuff as well as the 12 x 23 cm cuff in patients with arm circumference greater than 33 cm (group B = 26). Arm circumference in group A was 25 +/- 3 cm and in group B 38 +/- 3 cm (P less than 0.01). Systolic blood pressure (SBP) and diastolic blood pressure (DBP) in group A was 125 +/- 20 mmHg and 78 +/- 11 mmHg respectively with the TriCuff and 124 +/- 19 mmHg and 78 +/- 13 mmHg with the 12 x 23 cm cuff. In group B SBP and DBP with the TriCuff was 134.6 +/- 13.3 mmHg and 84 +/- 17 mmHg respectively compared with 132 +/- 15 mmHg and 83.8 +/- 16 mmHg measured by the 15 x 33 cm cuff. SBP and DBP with the 12 x 23 cm cuff was 139.8 +/- 16 mmHg and 90.8 +/- 14 mmHg respectively. Both these values are significantly higher (P less than 0.05) compared with the new cuff and the larger cuff. Using the 12 x 23 cm cuff in group B resulted in the false diagnosis of hypertension in 3 normotensive patients. The TriCuff gives accurate blood pressure measurements in patients with different arm circumferences and should prevent false-positive diagnoses of hypertension in obese patients.     

Arterial tonometry for noninvasive, continuous blood pressure monitoring during anesthesia.

Arterial tonometry is a technique used to measure arterial blood pressure noninvasively. The authors developed a new tonometer system containing an array of 15 piezoresistive pressure transducers, a mechanical positioning system, signal conditioning and multiplexing electronics, and a display and control console. The authors evaluated the accuracy, reliability, and clinical acceptability of this system by comparing tonometric blood pressure measurements with intraarterial blood pressure measurements in 60 anesthetized patients. Blood pressure was measured intraarterially in either the right or left radial artery by a Gould P23XL calibrated transducer, whereas blood pressure was measured by tonometer at the radial artery of the other arm. The tonometric waveform was similar to the intraarterial waveform. Simultaneous tonometer and intraarterial systolic blood pressures of the 60 patients (3,036 data sets) had an overall regression coefficient, r = 0.97, and an equation, regression equation = 0.95X + 5.8. Similar values were obtained for mean and diastolic pressures. Regression analyses of the paired tonometric and intraarterial blood pressure values showed good correlations in both sexes and in ages ranging from 8 to 82 yr (r = 0.94-0.97). Mean absolute values of error (precision) for the systolic, mean, and diastolic measurements did not differ significantly among the five systolic, five mean, and four diastolic pressure groups and ranged from 3.6 to 6.6 mmHg, with negligible bias, with intraarterial pressure used as the reference. Bias for the various pressure groups was small: -0.9-3.6 mmHg for systolic; -3.0-0.7 mmHg for mean; and -2.1-4.5 mmHg for diastolic. The "limits of agreement" (mean difference +/- two standard deviations) were within an acceptable range for clinical anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Twenty-four hour blood pressure profile and left ventricular hypertrophy early after renal transplantation

BACKGROUND: Left ventricular hypertrophy is common in renal transplant patients but the factors influencing its development remain to be determined. The present investigation was conducted to study the effect of blood pressure load on the left ventricular mass of recently transplanted patients using 24-h ambulatory blood pressure monitoring (ABPM). METHODS: We studied 30 renal transplant (RT) patients (36.1+/-13.7 years old, 11 males, 26 Whites, 4 diabetics, 15 under antihypertensive medication, 21 recipients of cadaver donors, and all treated with steroids, cyclosporin and azathioprine and with adequate (serum creatinine < 1.8 mg/100 ml) renal function). The median duration of dialysis treatment before transplant was 37 months, and the studies were performed during the first 40 days post-transplantation. Blood pressure was measured after a 15-min rest (casual blood pressure) and during a 24-h period with a SpaceLabs apparatus. Echocardiograms were obtained from all patients. RESULTS: Mean left ventricular mass index (LVMI) was 153+/-44 g/m2; casual systolic and diastolic BP (mmHg) was 152+/-25 and 92+/-13, whereas systolic and diastolic 24-h BP was 133+/-12 and 85+/-8, respectively. The systolic sleeping BP/awake systolic BP (SSBP/ASBP) ratio was 0.94+/-0.07, and 73% of the patients did not show a significant (>10%) fall of systolic blood pressure during sleep. Multivariate analysis showed that awake systolic blood pressure was the only variable that independently influenced LVMI after adjusting for confounding factors (regression coefficient = 0.49, p = 0.01). Casual systolic and diastolic BP, sleeping systolic and diastolic blood pressure, 24-h heart rate, age, race, gender, smoking, body mass index, duration of dialysis, diabetes, antihypertensive and immunosuppressive drugs and levels of hematocrit, creatinine and serum lipids did not correlate with LVMI. CONCLUSION: The data indicate that left ventricular hypertrophy during the early post-transplant period is mainly influenced by awake blood pressure load. They also suggest that ABPM may be more useful in the diagnosis and management of post-transplant hypertension than casual BP. The findings emphasize the importance of rigid blood pressure control in renal transplant recipients.     

Effect of Lisinopril on the progression of renal insufficiency in mild proteinuric non-diabetic nephropathies.

BACKGROUND: The aim of the study was to determine whether Lisinopril, an ACE-inhibitor (ACEi), was more effective than other antihypertensive agents in slowing the progression of non-diabetic chronic renal diseases in patients with baseline proteinuria < or =1.0 g/day. METHODS: In an open, multicentre study all eligible patients entered a 3 months run-in phase during which antihypertensive therapy (with exclusion of ACEi) was adjusted in order to obtain a supine diastolic blood pressure < or =90 mmHg and urinary protein excretion and renal function stability were verified. One hundred and thirty-one patients with chronic renal insufficiency (Clcr between 20-50 ml/min) because of primary renoparenchymal diseases and proteinuria < or =1.0 g/day, were randomized to Lisinopril (L=66) or alternative antihypertensive therapy (C=65). Changes in renal function were assessed by inulin (Clin) clearance. RESULTS: During the follow-up period of 22.5+/-5.6 months, Clin did not change significantly in group L (-1.31+/-0.6 ml/min/1.73 m(2)) differing significantly from group C in which it declined markedly (-6.71+/-3.6 ml/min/1.73 m(2)) (P<0.04). Seven patients experienced adverse events that prompted discontinuation of treatment: four in group L and three in group C; in addition seven patients showed severe deterioration in renal function requiring dialysis: two in group L and five in group C. The overall risk of the combined end-points: need for dialysis or halving of GFR was significantly higher in group C versus group L. During the study the mean value for systolic blood pressure was 137.8+/-14.6 SD mmHg in group L and 140.8+/-14.1 SD mmHg in group C; the mean difference between groups, during and at the end of the study, was 2 mmHg (NS). The mean diastolic blood pressure during the study was 83.8+/-8.6 SD mmHg in group L and 84.3+/-7.56 SD mmHg in group C; during and at the end of the study the mean diastolic difference between groups was 1 mmHG: CONCLUSION: This study, employing a sensitive measurement of renal function and with similar blood pressure in both groups, provides support to the hypothesis that ACEi have a specific renoprotective effect, in addition to blood pressure control, also in patients with mild proteinuria.     

Blood pressure changes after aortic coarctation surgery performed in adulthood

OBJECTIVE: The aim of this study was to assess the effect of aortic coarctation surgery in adult patients on arterial blood pressure in the early postoperative period. METHODS: Ninety-three adult patients (61 male, 32 female) aged 15-43 years who had operation since 1962 for aortic coarctation in Siyami Ersek Cardiovascular Surgery Center were retrospectively evaluated. Tube graft interposition was done in 31 patients; resection and end-to-end anastomosis were performed in 32 patients; 24 patients had undergone pathchplasty; and 6 patients by-pass shunting performed. The effect of surgery on the blood pressure was investigated. RESULTS: The mean systolic and diastolic blood pressure significantly reduced after operation (systolic 193.6 +/- 33.7 mmHg vs 147.4 +/- 22.0 mmHg, diastolic 99.8 +/- 17.9 mmHg vs 82.0 +/- 10.8 mmHg). From 93 patients (all with hypertension) 54 (58%) became normotensive after operation according to VIth Joint National Committee classification. The number of normotensive patients after operation was 28 (of 37) for 15-19 years age group, 14 (of 23) for the 20-24 years age group, 4 (of 16) for 25-29 years age group, 6 (of 11) for 30-34 years age group, and 2 (of 6) for the over 35 years old age group. CONCLUSION: The diastolic and systolic blood pressures reduce significantly in the adult patients operated for aortic coarctation. On the other hand, persistent hypertension seemed to increase in the older age groups in spite of the surgery.     

Fate of hypertension after repair of coarctation of the aorta in adults

BACKGROUND: Unrepaired aortic coarctation is known to have a detrimental effect on survival. The benefit of coarctation repair on systolic hypertension in adults has been questioned. This retrospective study was conducted to evaluate the impact of repair of aortic coarctation on systolic hypertension in adults. METHODS: Repair of aortic coarctation was performed in 84 patients aged 16-54 (mean 29) years. All patients were hypertensive before surgical intervention (mean systolic blood pressure 162 mmHg; mean diastolic blood pressure 93 mmHg). All patients underwent echocardiography and/or cardiac catheterization. The peak mean systolic gradient across the coarctation was 60 mmHg. The patients were followed after coarctation repair for between 1 and 12 (mean 5.2) years. RESULTS: There was significant regression of hypertension (P < 0.001) in all patients. Thirty-five patients (42 per cent) did not need any antihypertensive medication 3 months after surgery. The prevalence of hypertension at the last follow-up (after mean 5.2 years) was 31 per cent. CONCLUSION: Surgical repair of coarctation of the aorta in adults leads to regression of systolic hypertension and a decreased requirement for antihypertensive medication.     

Arteriovenous fistula closure after renal transplantation: a prospective study with 24-hour ambulatory blood pressure monitoring

We prospectively evaluated the effects of arteriovenous fistula closure on 24-hour ambulatory blood pressure measurements and on left ventricular geometry assessed by echocardiography. Sixteen kidney transplant recipients were studied before and 1 month after surgical fistula closure. The mean of 24-hour diastolic blood pressure increased from 77+/-7 mmHg to 82+/-8 mmHg (P=0.003) without systolic changes. The diastolic blood pressure increase correlated with the reduction in left ventricular mass (P=0.0034). In multivariate analysis, the diastolic blood pressure increase best correlated with preoperative cardiac index (P=0.01). After a similar time delay between two studies, blood pressure remained unchanged in 14 kidney transplant controls with a patent fistula not scheduled for closure. Because the increase in diastolic blood pressure after arteriovenous fistula closure occurred regardless of the preoperative level of diastolic pressure, we suggest that blood pressure should be monitored after fistula closure, particularly when preoperative diastolic blood pressure is borderline or elevated.     

Hypoxic reperfusion limits functional impairment following cardioplegic arrest in isolated rat heart

BACKGROUND: Reperfusion injury decreases both systolic contractility and diastolic compliance. Several studies indicate that the sustained decrease in diastolic compliance is mainly due to reactive oxygen intermediates (ROI) generation and calcium overload. METHODS: Male Wistar isolated rat hearts were divided into 2 groups (n=10 each), perfused according to Langendorff technique and exposed to 45 min of ischemia. Hearts belonging to the first group were reperfused with Krebs-Henseleit solution at 600 mmHg pO2; a 150 mmHg pO2 perfusate was utilized in the second group during the first minute and switched to 600 mmHg pO2 thereafter. Modifications in diastolic compliance and systolic contractility were assessed by changes in left ventricular end-diastolic (LVEDP) and developed pressure (LVDP), and first derivative of the pressure curve (dP/dt). RESULTS: Increase in LVEDP values, with respect to pre-ischemic data, were detected at 1, 5, 10, 20 min following reperfusion at 600 mmHg pO2, and were respectively: +40.17+/-18.61, +57.5+/-28.8, +59.8+/-30.5 and +63.2+/-34.1 mmHg. At 150 mmHg pO2 they were: +15.69+/-13.13, +22.4+/-14.1, +26.2+/-13.7 and +28.9+/-15.8, with a significant difference within the first 20 min (p<0.05). At high pO2 levels, LVDP decreased of 53.0+/-27.35, 60.5+/-22.6, 59.8+/-23.3 and 50.7+/-25.0 mmHg, versus 42.7+/-25.7, 38.0+/-29.5, 39.2+/-30.9 and 38.7+/-32.7 mmHg at lower pO2 (p=NS). The correspondent values of the dP/dt were 37.8+/-27.7, 30.1+/-17.2, 32.2+/-13.6 and 35.4+/-14.0% of pre-ischemic values at high pO2, versus 43.3+/-27.09, 51.9+/-25.1, 50.1+/-24.6 and 53.1+/-29.9% at lower pO2. Statistical significance was lower for LVDP and dP/dt than LVEDP. CONCLUSIONS: Diastolic functional impairment was partially reduced within the first 20 min following low pO2 reperfusion, but without any significant improvement of contractility.     

Effect of recombinant human erythropoietin therapy on ambulatory blood pressure and heart rate in chronic haemodialysis patients.

Systemic hypertension as assessed by causal blood pressure measurements is a frequently reported side-effect of recombinant human erythropoietin (rHuEpo) treatment. We investigated the effect of rHuEpo treatment on the 24-h ambulatory blood pressure and heart rate profiles of 13 chronic haemodialysis patients. After 3-4 months of rHuEpo therapy it was found that the mean haematocrit had increased from 24.5 +/- 1.0% to 32.0 +/- 1.1% (P less than 0.005), while body-weight and control of uraemia as assessed by routine laboratory data remained unchanged. Despite gradual and incomplete correction of anaemia by use of low doses of rHuEpo, increases in the ambulatory systolic and diastolic blood pressure were found. The greatest increases affected day-time systolic blood pressure and night-time diastolic blood pressure, and these increases were significant (P less than 0.05). As a result, pulse pressure increased during day-time (P less than 0.05) while the night-time decline in diastolic blood pressure disappeared. An increase in peripheral resistance after partial correction of renal anaemia might explain these observations. rHuEpo therapy increased the percentage of abnormal ambulatory blood pressure measurements (defined as systolic blood pressure greater than 140 mmHg and/or diastolic blood pressure greater than 90 mmHg) from 33% to 52% (P less than 0.05) while in contrast, mean casual prehaemodialytic and posthaemodialytic blood pressure values remained unchanged. We conclude that changes in 24-h blood pressure profiles should be carefully assessed by ambulatory blood pressure monitoring in haemodialysis patients treated with rHuEpo, since these changes are likely to be missed when only causal blood pressures are measured.     

Dual blockade of the renin-angiotensin system in type 1 patients with diabetic nephropathy.

BACKGROUND: Albuminuria and hypertension are predictors of poor renal and cardiovascular outcome in patients with diabetes. Approximately 30% of type 1 patients with diabetic nephropathy (DN) have albuminuria >1 g/day, and blood pressure >135 and/or >85 mmHg despite antihypertensive therapy with recommended doses of ACE inhibitor (ACEI) and diuretics. We tested the effect of dual blockade of the renin-angiotensin system (RAS) in these patients. METHODS: We performed a randomised double blind crossover trial with 2 months treatment with Irbesartan 300 mg o.d. and placebo added on top of previous antihypertensive treatment. We included 21 type 1 patients with DN responding insufficiently to ACEI and diuretics, as defined above. At the end of each treatment period, albuminuria, 24-h blood pressure and glomerular filtration rate (GFR) were measured. RESULTS: Addition of 300 mg Irbesartan to the patients' usual antihypertensive therapy induced a mean reduction in albuminuria of 37% (95% CI 20-49, P<0.001); from 1574 mg/24 h (95% CI 1162-2132) to 996 mg/24 h (95% CI 699-1419), a reduction in 24-h blood pressure of 8 mmHg systolic (95% CI -2 to 18) and 5 mmHg diastolic (95% CI 1-9) (P=0.11 and 0.01, respectively) (from placebo, mean (SE) 146 (4)/80 (2) mmHg). GFR remained unchanged. Serum potassium increased (mean 4.3 to 4.6 mmol/l, P=0.02). Intervention to reduce serum potassium was needed in two patients with GFR <35 ml/min/1.73 m(2). Otherwise the dual blockade with Irbesartan was safe and well tolerated. CONCLUSIONS: Dual blockade of the RAS may offer additional renal and cardiovascular protection in type 1 patients with DN responding insufficiently to conventional antihypertensive therapy, including recommended doses of ACEI and diuretics.     

Comparison of indapamide and low-dose hydrochlorothiazide monotherapy in black patients with mild to moderate hypertension.

OBJECTIVES: To assess, using ambulatory blood pressure monitoring (ABPM), the antihypertensive efficacy of hydrochlorothiazide 12.5 mg and indapamide 2.5 mg given as a monotherapy over 3 months to black patients with mild to moderate essential hypertension. DESIGN: Single-centre, prospective, randomised open pilot study in three phases: (i) 1-week drug-free washout period; (ii) 2-week placebo run-in phase; and (iii) 3-month prospective open-label active treatment period. RESULTS: Forty-two black patients with mean daytime diastolic BP (DBP) > or = 90 mmHg and < or = 115 mmHg (mean age 57 +/- 11 years, 28 women/14 men) were enrolled into the study. Overall, a profound and sustained BP reduction was achieved with indapamide at 3 months (N = 20). The 24-hour BP decreased from 150 +/- 17/94 +/- 6 mmHg to 130 +/- 19/82 +/- 9 mmHg (P < 0.0001 for systolic BP (SBP) and DBP at 3 months versus baseline); the mean daytime BP decreased from 155 +/- 15/98 +/- 6 mmHg to 134 +/- 18/87 +/- 10 mmHg (P < 0.0001 for SBP and DBP at 3 months versus baseline). The overall control (mean daytime DBP < 90 mmHg) and response (decrease in daytime DBP > or = 10 mmHg) rates achieved with indapamide were 10/20 (50%) and 13/20 (65%), respectively. In contrast, monotherapy with hydrochlorothiazide resulted in more modest BP reduction and control and response rates at 3 months (N = 22). The 24-hour BP decreased from 147 +/- 14/94 +/- 7 mmHg to 139 +/- 19/88 +/- 2 mmHg (P < 0.05 for DBP at 3 months versus baseline, P = NS for SBP); the mean daytime BP decreased from 151 +/- 14/98 +/- 5 mmHg to 144 +/- 16/93 +/- 10 mmHg (P < 0.05 for DBP at 3 months versus baseline, P = NS for SBP). The corresponding control and response rates were 7/22 (32%) and 8/22 (36%). Both hydrocholorothiazide and indapamide caused significant hypokalaemia. CONCLUSIONS: Monotherapy with indapamide is associated with greater BP reduction and control and response rates than monotherapy with low-dose hydrochlorothiazide and may be an appropriate choice of antihypertensive diuretic therapy in black South African patients with mild to moderate hypertension.     

Supervised atenolol therapy in the management of hemodialysis hypertension

BACKGROUND: Uncontrolled hypertension continues to be a common problem, particularly in noncompliant hemodialysis patients. Atenolol, a water soluble beta-blocker has a prolonged half-life in renal failure and may serve as a useful antihypertensive agent in these patients. METHODS: Hypertension was diagnosed by ambulatory blood pressure monitoring for 44 hours during an interdialytic interval in eight chronic hemodialysis patients receiving no antihypertensive therapy. An average daytime blood pressure greater than 140/90 mm Hg or an average nighttime blood pressure greater than 120/80 mm Hg was used to define uncontrolled hypertension. Patients were then administered atenolol (25 mg) following hemodialysis three times a week. The efficacy of therapy was judged by ambulatory blood pressure monitoring three weeks after instituting atenolol therapy. Blood pressure loads above the threshold blood pressures during the day or night were also calculated and compared before and after three weeks of atenolol therapy. RESULTS: The mean 44-hour ambulatory blood pressure (ABP) fell from 144 +/- 14/80 +/- 7 mm Hg to 127 +/- 13/69 +/- 10 mm Hg (P < 0.001). The heart rate fell from 85 +/- 11 to 70 +/- 11 beats per minute. The systolic and diastolic blood pressure load was reduced from 71 +/- 25% and 30 +/- 24% to 35 +/- 26% and 11 +/- 17%, respectively (P < 0.001). There was a persistent antihypertensive effect over 44 hours. The blood pressure reduction was achieved without any increase in intradialytic symptomatic or asymptomatic hypotensive episodes, reduction in delivered dialysis, or statistically significant changes in serum potassium or glucose. CONCLUSIONS: A supervised administration of atenolol following hemodialysis effectively and safely controls hypertension in chronic hemodialysis patients. This therapy can be particularly valuable for noncompliant hemodialysis patients.     

Ambulatory blood pressure in microalbuminuric type 1 diabetic patients.

Twenty-four-hour ambulatory blood pressure (AMBP) was performed in microalbuminuric (micro.) type 1 diabetic patients, with the aim of comparison with a matched group of normoalbuminuric patients (normo.) and healthy controls. Thirty-four patients without antihypertensive medication were investigated in each group. Urinary albumin excretion (UAE) for micro. was (geometric mean, tolerance factor microgram/min) 51.7 x/divided by 1.94, 5.1 x/divided by 1.88 for normo. and 5.2 x/divided by 1.75 for controls. Twenty-four-hour AMBP (mean systolic/diastolic mm Hg +/- SD) was significantly higher in micro. (131 +/- 10/78 +/- 7) than in normo. (122 +/- 8/73 +/- 6; P less than 0.001/P less than 0.01). No 24-hour AMBP difference between normo. and controls (120 +/- 9/71 +/- 7) was found. No difference in the night/day ratio of blood pressure was found between the diabetic groups. Coefficient of variation for day time systolic measurements did not show any intergroup difference. Systolic day time blood pressure for the pooled diabetic group correlated significantly with UAE (r = 0.45, P less than 0.001), whereas no significant correlation with auscultatory systolic values in the clinic was found (r = 0.21; P = 0.09). In conclusion, blood pressure in micro. as compared to normo. is not more labile but is elevated day and night without significant alteration of the diurnal rhythm. AMBP reflects the association between UAE and blood pressure more precisely than clinical measurements and may be preferable for identifying candidates for antihypertensive treatment.     

Optimal dose of losartan for renoprotection in diabetic nephropathy.

BACKGROUND: Angiotensin II subtype-1 receptor antagonists represent a valuable new class of drugs in the treatment of diabetic nephropathy. The aim of our study was to evaluate the optimal dose of losartan for renoprotection and blood pressure reduction in diabetic nephropathy. METHODS: Fifty consecutive hypertensive type 1 diabetic patients with diabetic nephropathy received increasing doses of losartan, 50, 100, and 150 mg once daily in three periods each lasting 2 months. At baseline and at the end of each treatment period, albuminuria, 24-h blood pressure (TM2420 A&D), and glomerular filtration rate (GFR) ([(51)Cr]EDTA plasma clearance) were determined. RESULTS: Baseline values of albuminuria (geometric mean (95% CI)) and GFR (means+/-SEM) were 1138 (904-1432) mg/24 h and 91+/-3 ml/min/1.73 m(2), respectively. The blood pressure at baseline was 155/81+/-3/2 mmHg. All doses of losartan reduced albuminuria and blood pressure. Albuminuria was reduced by 30% (95% CI (15-41)) on losartan 50 mg, 48% (35-57) by losartan 100 mg, and 44% (32-56) by losartan 150 mg (all P values <0.01 vs baseline). Losartan 100 mg daily was significantly more effective than 50 mg daily in reducing albuminuria (P<0.01) without differences between the two high doses. Losartan 50, 100, and 150 mg daily decreased systolic/diastolic blood pressures by 7/4, 12/6, and 10/5 mmHg, respectively (all P<0.05). Losartan 100 mg daily was more effective than 50 mg daily in reducing systolic, diastolic, and mean arterial blood pressure (P=0.05), without differences between the high doses. Treatment with losartan 100 and 150 mg lowered GFR by 4 ml/min/1.73 m(2) (P<0.05). CONCLUSION: Our study suggests that the optimal dose of losartan is 100 mg daily for renoprotection and blood pressure reduction in type 1 diabetic patients with diabetic nephropathy.     

Correlation and linear regression between blood pressure decreases after a test dose injection of propofol and that following anaesthesia induction

Propofol reduces systemic vascular resistance and suppresses cardiac function when injected rapidly. In this study we investigated whether blood pressure decrease after a minimal dose (test-dose) injection of propofol correlates with that after an induction-dose injection. Patients were randomly divided into two groups; anaesthesia was induced in group A (n = 60) using 1.5 mg/kg propofol and in group B (n = 61) using 2.0 mg/kg. Blood pressure reduction after a minimal dose injection (0.4 mg/kg) was examined non-invasively prior to anaesthetic induction. Bispectral Index monitoring was measured and sedation level scored to evaluate anaesthetic depth. After the minimal dose injection, 18 of 121 patients showed behaviour suggesting minor disinhibition, five patients were sedated and seven were drowsy. Oxygen saturation was not significantly changed after test-dose injection. Reduction in systolic blood pressure (mean +/- SD) was 17 +/- 11 mmHg after the minimal dose injection, 42 +/- 20 mmHg after a 1.5 mg/kg induction dose injection, and 42 +/- 22 mmHg after a 2.0 mg/kg induction-dose injection. In both groups, blood pressure after induction was significantly lower than the control value (P < 0.05). In both groups, a positive correlation was observed between blood pressure reduction after the minimal dose injection and that after the induction-dose injection [P < 0.01, R value for systolic blood pressure correlation in group A 0.712 (P < 0.01) and in group B 0.758 (P < 0.01)]. We concluded there was a positive correlation between blood pressure reduction after a minimal (test-dose) injection and that after an induction-dose injection.     

Efficacy and safety of losartan in patients with proteinuria

The renoprotective effect and safety of an angiotensin II receptor blocker, losartan, were studied in 11 diabetic and 14 nondiabetic patients with a daily urinary protein excretion >500 mg. Once-daily losartan was administered to all patients for 16 weeks without diuretics or other antihypertensive agents. A daily dose of 50 mg was given to those patients with a sitting systolic blood pressure of between 130 and 170 mm Hg; 25 mg was given to patients with a systolic blood pressure of between 110 and 130 mm Hg. Sixteen patients (6 diabetic and 10 nondiabetic patients) had a more than 25% decrease of their daily urinary protein excretion (response rate 64%). The mean decrease in these 16 patients was 57 +/- 17% (p < 0.05). Two patients (1 diabetic and 1 nondiabetic) had more than a 25% increase of their urinary protein excretion. The trough sitting systolic blood pressure of all patients (n = 25) decreased from 142 +/- 17 to 125 +/- 13 mm Hg (p < 0.05) and the trough sitting diastolic blood pressure from 87 +/- 11 to 78 +/- 11 mm Hg (p < 0.05). Serum uric acid was measured in 16 patients; a decrease from 7.3 +/- 1.6 to 6.6 +/- 1.4 mg/dl (a 9.6% decrease, p < 0.05) was found after 16 weeks. Our study showed that in both diabetic and nondiabetic proteinuric patients once-daily losartan, given as monotherapy at doses of 25 or 50 mg, was effective in reducing blood pressure, serum uric acid levels, and daily urinary protein excretions.     

Ambulatory blood pressure monitoring in hypertensive CAPD patients

The periodic structure of 24-hour blood pressure variation(circadian rhythm of blood pressure by ambulatory blood pressure monitoring(ABPM) in hypertensive CAPD patients was investigated by a new method of analysis based upon the maximum entropy method(MEM). In addition, this method allows the adequacy of antihypertensive therapies to be evaluated in such patients. The results were as follows; 1) The frequency of non-dipper type hypertension was 88%(36/41 cases), and the remaining 12% (5/41) were dipper type hypertension patients. The rise in morning blood pressure(morning surge: MS) was noted in 64% of the former. 2) Night time systolic blood pressure(182 +/- 22 mmHg, n = 36) was higher in patients with non-dipper type hypertension than in those with the dipper type(151 +/- 17 mmHg, n = 5, p < 0.01). 3) The standardized level of systolic blood pressure(SLSBP) calculated by MEM analysis in patients with non-dipper type hypertension(177 +/- 7 mmHg) was comparable with that in those with dipper type hypertension(168 +/- 13 mmHg, ns). 4) Treatment with long-acting Ca antagonist alone significantly reduced both SLSBP and the area over the SLSBP from 188 +/- 18 mmHg to 160 +/- 7 mmHg(p < 0.01, n = 8), and area over the SLSBP from 2,735 +/- 340 mmHg.hr to 1,945 +/- 298 mmHg.hr(p < 0.01, n = 8). 5) In addition to long-acting Ca antagonist, administration of alpha 1-blocker given at bed time was significantly efficacious in reducing the rise in morning blood pressure, MS. The present study using MEM analysis of ABPM suggests that the blood pressure profile of hypertensive CAPD patients is characterized by a non-dipper type dominance and a frequent morning surge. Furthermore, the combined therapy with long-acting Ca antagonist and alpha 1-blocker was substantially effective both in reducing the overall blood pressure level, and in inhibiting the MS. This combined antihypertensive therapy may be potentially useful to prevent CAPD patients from the future development of cardiovascular complications.