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Biomedical subjects

H Ring-Larsen

Publications and source records attributed to H Ring-Larsen.

At least 55 records · Page 3Linked to original sources
PubMed1988

Plasma catecholamine level and portal venous pressure as guides to prognosis in patients with cirrhosis.

Circulating noradrenaline is increased in patients with cirrhosis, especially in decompensated patients with ascites. Eighty-one patients with alcoholic cirrhosis were followed for up to 8 years in order to establish a possible relationship between plasma catecholamines, haemodynamics, and routine clinical and biochemical variables and survival. Forty-seven (58%) of the patients died during the follow-up period. Univariate analysis showed that plasma noradrenaline and adrenaline concentrations, portal pressure, indocyanine green clearance, serum sodium, bilirubin, and albumin concentrations, and the presence of ascites or cardiovascular disease were of significant prognostic value. In a multivariate analysis (Cox regression model), plasma noradrenaline concentration, portal pressure, serum bilirubin concentration, and the presence of ascites and cardiovascular disease remained significant independent predictors of survival. The results suggest that determination of the circulating level of noradrenaline and portal pressure may add to the prognostic information on survival obtained from routine tests. Thus, the activity of the sympathetic nervous system may indicate the severity of cirrhosis with respect to survival.

Adult↗
PubMed1988

Kidney, lower limb and whole-body uptake and release of catecholamines in alcoholic liver disease.

Regional (kidney, lower limb) and whole-body kinetics of endogenous noradrenaline (NA) and tritium-labelled L-noradrenaline (3H-NA) were determined in patients with alcoholic liver disease (one alcoholic hepatitis, 12 cirrhosis) and in control subjects (n = 6) in order to get information on the sympatho-adrenal system in liver disease. Arterial NA was significantly elevated in ascitic patients (median 2.5 nmol/l, n = 9, P less than 0.05) as compared to non-ascitic patients (1.6 nmol/l) and controls (1.7) nmol/l). NA spillover per unit NA inflow was increased in the kidney in patients with ascites (0.69 vs. 0.45 pmol/min.g per pmol/min.g in controls, P less than 0.005) but not in the lower limb (0.23 vs. 0.49 in controls, P less than 0.01). In patients with ascites the spillover rate of NA from the kidney into plasma (1.9 pmol/min.g) was significantly increased (P less than 0.02) compared to controls and non-ascitic patients (1.2 and 1.0 pmol/min.g, respectively. Patients and control kidneys and limbs extracted almost the same fraction of 3H-NA (0.34 vs. 0.32 NS and 0.34 vs. 0.37 NS, respectively). Whole-body clearance of 3H-NA was not significantly different in cirrhotics and controls (median 0.89 vs. 0.91 l/min.m2), indicating that the raised NA in decompensated cirrhosis reflects enhanced sympatho-adrenal activity rather than decreased metabolism of this amine. Our results do not point towards a uniform sympatho-adrenal overactivity in decompensated cirrhosis, but rather indicate regional differences with different order of NA spillover. The renal sympathetic overactivity, as indicated by the increased renal NA overflow, is likely to be important to the decreased renal perfusion and increased salt-water retention characteristic of this clinical condition.

Adult↗
PubMed1987

Hepatic intestinal uptake and release of catecholamines in alcoholic cirrhosis. Evidence of enhanced hepatic intestinal sympathetic nervous activity.

Hepatic intestinal and whole body plasma clearance and appearance of noradrenaline (NA) was quantified in patients with alcoholic cirrhosis (n = 12) and in controls (n = 6). As NA may be released as well as removed in the same vascular bed, infusion of tritium labelled NA (3H-NA) was carried out during hepatic vein catheterisation in order to determine both flux rates. In alcoholic cirrhosis plasma concentrations of endogenous NA and adrenaline (A) were significantly above control values (NA: median 2.4 v 1.7 nmol/l, p less than 0.02; A: 0.38 v 0.19 nmol/l, p less than 0.01). Whole body clearance of 3H-NA equal in the two groups (1.6 v 1.7 l/min, ns), while as the overall appearance rate of NA was significantly higher in alcoholic cirrhosis (4.2 v 2.6 nmol/min, p less than 0.02) indicating an enhanced sympathoadrenal activity in this group. The hepatic intestinal clearances of A, NA, and 3H-NA were not significantly different in patients and controls, but the estimated hepatic intestinal spillover rate of NA was 0.24 nmol/min in patients as compared with 0.0 nmol/min in controls (p less than 0.02). As a result of portosystemic shunting in cirrhosis the present estimation of NA spillover represents a minimum value. Our results indicate that the augmented circulating catecholamines in cirrhosis do not result from diminished removal but are contributed to from increased sympathetic nervous activity in the hepatic intestinal area (enhanced mesenteric sympathetic nervous activity).

Adult↗
PubMed1986

Diuretic treatment in decompensated cirrhosis and congestive heart failure: effect of posture.

The diuretic effect of the supine position was evaluated in six patients with cirrhosis and ascites and six with congestive cardiac failure. After fasting overnight in bed the patients received bumetanide 1 mg intravenously and were then immediately randomly assigned to either bed rest in the supine position or normal daily activity in the upright position for the next six hours. Two days later the procedure was repeated, the patients being assigned to the other posture. The diuretic response was similar in patients with heart failure and cirrhosis, and was significantly greater in the supine than in the upright position: mean 1133 v 626 ml/6 h (p less than 0.01). The natriuresis was similarly larger during recumbency: mean sodium 96 v 45 mmol(mEq)/6h (p less than 0.01), and the excreted potassium in six hours was similar in both postures. The glomerular filtration rate was 100 and 66 ml/min (p less than 0.01) and heart rate 76 and 83 beats/min (p less than 0.01) in the supine and upright positions respectively. Plasma concentrations of noradrenaline, renin, and aldosterone were all raised even when the patient adopted the supine position, and a further significant rise was observed during the upright position. The results suggest that the attenuated response to intravenous bumetanide in the upright position and during normal daily activity may be due to the activation of several homeostatic mechanisms that may reduce the excretion of water and salt.

Adult↗
PubMed1986

Pulmonary extraction of circulating noradrenaline in man.

Pulmonary plasma kinetics of endogenous noradrenaline (NA) and tritium labelled L-noradrenaline (3H-NA) was studied in fifteen subjects during pulmonary arterial catheterization. Plasma NA concentration in femoral artery ranged from 0.5 to 8.2 nmol l-1, mean 2.3 nmol l-1, which was not significantly different from that of age-matched control subjects. The lungs extracted both endogenous NA and 3H-NA significantly, but no significant pulmonary extraction of endogenous adrenaline was found. The pulmonary arterial-systemic arterial extraction ratio of NA was mean 0.08 (n = 9) as compared to that of 3H-NA: mean 0.07 (n = 8, NS). Likewise mean pulmonary clearances of NA and 3H-NA were not significantly different (97 ml min-1 X M-2 v. 124 ml min-1 X M-2, NS). Estimated whole-body clearance of noradrenaline was mean 0.80 l min-1 X M-2 (n = 6) while the pulmonary clearance amounted to 19% of this value. The small, but significant, pulmonary extraction of circulating noradrenaline implies that whole-body clearance, as estimated from infusion rate and systemic arterial sampling, will be overestimated by approximately 7%. As pulmonary extraction of NA and 3H-NA was almost identical, the results indicate no significant pulmonary contribution to circulating noradrenaline.

Adult↗
PubMed1986

Catecholamines in plasma from artery, cubital vein, and femoral vein in patients with cirrhosis. Significance of sampling site.

The concentration of noradrenaline (NA) and adrenaline (A) was measured in arterial, cubital venous and femoral venous plasma in order to determine possible differences in different vascular beds in the peripheral circulation. In patients with cirrhosis, arterial plasma NA (median 2.54 nmol/l, n = 40) was significantly increased compared to controls (median 1.42 nmol/l, n = 17, p less than 0.001). Arterial plasma A was not significantly different (0.41 vs. 0.38 nmol/l). Cubital and femoral venous NA and A were positively correlated to the arterial values in both cirrhosis and controls (r = 0.86 to 0.97, p less than 0.01). In cirrhosis, median cubital venous:arterial NA ratio was significantly above unity (1.14, n = 36, p less than 0.001) as compared to unity in controls (1.00, n = 8), whereas the femoral venous:arterial NA ratio was similar in cirrhosis and controls, and significantly below unity (median 0.86 and 0.87). Cubital venous:arterial and femoral venous:arterial A ratios were significantly below unity in cirrhosis as well as in controls. The results point towards an enhanced sympathetic nervous activity in cirrhosis which may involve, among other organs, the upper limb (especially the skin of forearm and hand). To assess circulating levels of catecholamines, the importance of arterial sampling is stressed as peripheral venous samples may also reflect local factors.

Adult↗
PubMed1985

Sympathetic nervous activity in cirrhosis. A survey of plasma catecholamine studies.

This review summarizes recent progress in the knowledge of catecholamines in cirrhosis. Compensated patients have normal plasma concentration of noradrenaline. Highly elevated plasma noradrenaline concentration in decompensated patients indicates that the sympathetic nervous system is enhanced in this condition. This may especially apply to the sympathetic tone in the kidney, as evaluated by regional measurements of noradrenaline overflow. Hepatic elimination of catecholamines is only slightly reduced. Activation of the sympathetic nervous system seems to play an important role in the avid sodium-water retention and decreased kidney perfusion observed in decompensated cirrhosis. Volume- en baro-receptors are likely to elicit this overactivity. The decreased systemic arterial blood pressure may be a primary event which is in part counteracted by enhanced sympathetic nervous activity and activated renin-angiotensin system. The role of a non-volume-dependent hepatic baro-receptor, false neurotransmitters, postsynaptic receptors, and autonomous neuropathy are yet unknown issues of further research.

Blood Pressure↗
PubMed1985

Bed rest and increased diuretic treatment in chronic congestive heart failure.

To elucidate the effect of bed rest used as an adjunct to increased diuretic treatment, twelve patients with chronic congestive heart failure (CHF) had a 50% increase in loop diuretic dosage and were allocated to either continuous bed rest or bed rest during nights only. The 24-hour bed rest group reduced their weight significantly (mean +/- SEM: 2.00 +/- 0.79 kg, P less than 0.001), whereas the night bed rest group had no significant weight reduction (1.10 +/- 0.37 kg, 0.1 less than P less than 0.2) during three days of observation. Furthermore, the 24-hour bed rest group had a significantly increased diuresis (P less than 0.05) during the first day of the study and a tendency towards increased natriuresis. The cumulated diuresis for the two groups (24-hour bed rest versus night bed rest) during the three days of study were 7773 +/- 700 ml and 5861 +/- 909 ml (0.05 less than P less than 0.1), respectively. Plasma concentrations of adrenaline, noradrenaline, renin and aldosterone were increased, as measured in the supine position. No significant differences were found between the two groups. Plasma concentrations of antidiuretic hormone were within normal limits. In conclusion, continuous bed rest is a reasonable adjunct to diuretic treatment in patients with CHF.

Adult↗
PubMed1985

Circulating noradrenaline and central haemodynamics in patients with cirrhosis.

Cardiovascular haemodynamics and circulating catecholamines were studied in 22 patients with cirrhosis. Arterial plasma noradrenaline (NA) was significantly increased (median, 0.48 ng/ml, versus controls, 0.24 ng/ml; n = 17; P less than 0.001), indicating enhanced sympathetic nervous activity. Heart rate was also increased (88 min-1 versus controls, 68 min-1; P less than 0.001), and mean arterial blood pressure was significantly decreased (81 mm Hg, versus controls, 88 mm Hg; P less than 0.002). Cardiac output was above the upper reference limit in eight patients and below the lower limit in two patients. Arterial NA was inversely correlated to stroke volume (r = -0.55; P less than 0.01) and to cardiac output (r = -0.53; P less than 0.02). Statistically significant relationships could not be demonstrated between NA and heart rate, arterial blood pressure, or right atrial pressure, but NA was slightly positively correlated to systemic vascular resistance (r = 0.51; P less than 0.02). The results may suggest that a relatively insufficient cardiac performance in the hyperkinetic circulatory state in cirrhosis may elicit an enhanced sympathetic nervous activity, which may contribute to maintenance of cardiovascular homeostasis.

Adult↗
PubMed1984

Splanchnic and renal elimination and release of catecholamines in cirrhosis. Evidence of enhanced sympathetic nervous activity in patients with decompensated cirrhosis.

Plasma noradrenaline (NA) and adrenaline (A) concentrations were determined in different vascular areas in 32 patients with cirrhosis and in nine controls during a right sided heart, liver, and renal vein catheterisation. The patients were divided into four groups: (I) Compensated (without ascites); (II) Recompensated on diuretic treatment because of former ascites; (III) Decompensated (with ascites) without treatment and (IV) Decompensated on diuretic treatment. Median arterial noradrenaline concentrations were 1.48, 1.07, 2.66, 4.14 and 2.50 nmol/l in controls, group I, II, III, and IV, respectively, the three last mentioned values being significantly raised (p less than 0.01). Median arterial adrenaline concentrations were not significantly increased. In patients arterial-hepatic venous extraction ratios of noradrenaline and adrenaline were on the average 25% (p less than 0.01) and 20% (p less than 0.02) less than those of the controls, indicating a slightly reduced splanchnic elimination of catecholamines in cirrhoses. In controls and group I significant renal venous-arterial noradrenaline differences were absent (0.00 and 0.03 nmol/l) while renal venous-arterial noradrenaline differences were significantly increased in groups II, III and IV (0.47, 0.53 and 0.68 nmol/l, p less than 0.01), indicating a significant net release of noradrenaline from the kidneys in recompensated and decompensated patients. Renal extraction of adrenaline was normal. In conclusion, increased arterial noradrenaline in decompensated and recompensated cirrhosis is only to a limited extent owing to reduced net splanchnic elimination. More likely the increase is caused by release of noradrenaline from the kidneys and possibly other organs indicating enhanced sympathetic nervous tone in these conditions.

Adult↗
PubMed1984

Determination of albumin transport rate between plasma and peritoneal space in decompensated cirrhosis.

Plasma-to-peritoneal transport rate of albumin (TERperit.space) was determined in eighteen patients with decompensated cirrhosis by sampling ascitic fluid after i.v. injection of 125I-labelled serum albumin. Median TERperit.space was 0.30% of the intravascular albumin mass (IVM) per hour (range 0.10-0.59). The transport rate of albumin from ascitic fluid back to plasma was measured in eight patients by plasma sampling after intraperitoneal injection of 131I-labelled serum albumin. After correction for tracer re-extravasation this back transport (median 0.31, range 0.07-0.44% IVM/h-1) was not significantly different from the simultaneously determined TERperit.space, indicating steady state with respect to albumin flux. Analysis of errors of the method was performed from experiments in pigs, and it is concluded that especially a high content of non-protein bound iodine and even minor bleeding from the abdominal puncture may lead to overestimation of TERperit.space, whereas systematic understimation seems less likely. This may besides differences in patient selection and unsteady state, account for the discrepancy between the present relatively low value and earlier reports on much higher values of TERperit.space in cirrhosis.

Adult↗
PubMed1984

Decreased blood platelet volume and count in patients with liver disease.

Mean platelet volume (MPV) and count (PLT) were assessed in patients with moderately affected liver function. PLT was significantly decreased in patients with liver disease (197 X 10(9)l-1 +/- 87 (SD), no. = 79) compared with that of controls (273 X 10(9)l-1 +/- 53 (SD), no. = 37, P less than 0.001). MPV in patients with liver disease (9.25 +/- 1.14 fl) was significantly lower than that of controls (10.52 +/-0.74 fl, P less than 0.001). In control subjects MPV and PLT were inversely correlated (r = -0.48, P less than 0.01), but statistical significance was not found in patients with liver disease (r = -0.2, 0.05 less than P less than 0.1). It is concluded that the low MPV and PLT are compatible with an intravascular activation (loss of granules) and increased consumption of platelets, which may take place in the diseased liver even in patients with a relatively well preserved liver function.

Adult↗
PubMed1984

Whole body and regional clearances of noradrenaline and adrenaline in man.

The whole body clearance of noradrenaline (NA) was measured in seven patients pre- and postoperatively. L-3H-NA was infused intravenously for 90 min and steady-state concentrations of L-3H-NA were measured in both arterial and peripheral venous blood. Preoperatively, in the resting supine position the clearance values based on arterial and venous sampling averaged 1.4 and 2.5 l/min, respectively (p less than 0.02). The difference in clearance values was due to peripheral uptake of NA averaging 45%. The plasma appearance rate on NA averaged 2.4 nmol/min before surgery and it increased to 9.5 nmol/min postoperatively (p less than 0.02). The plasma clearance of NA did not change. These results indicate that the calculation of plasma NA clearance based on venous sampling results in values that are too high. Furthermore, such values may be influenced by individual variations in the peripheral uptake of NA, since we found no correlation between clearance values based on venous and arterial sampling. In other experiments we measured the influence of physical exercise in young healthy subjects on the clearance rate of plasma adrenaline (A). The clearance of A, which at rest averaged 1.9 l/min tended to increase at low work loads and to decrease below resting levels at high exercise intensity. The changes were, however, small (+/- 20% of resting values). The regional extraction ratio of NA was 0.5 to 0.6 in the forearm, the liver and the kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗