Hemodynamic and oxygen transport effects of dobutamine in critically ill general surgical patients

The effects of dobutamine on hemodynamic and oxygen transport were evaluated in 43 studies on 34 critically ill general (noncardiac) surgical patients. Dobutamine, beginning at a low dose (2.5 micrograms/kg X min) significantly increased cardiac index (CI), oxygen delivery (DO2), and oxygen consumption (VO2), while decreasing mean arterial pressure, pulmonary artery and wedge pressures, and systemic and pulmonary vascular resistances; blood gases, pH, and pulmonary shunt were not significantly changed. These effects were seen in postoperative and septic patients, as well as in patients with normal, low, and high control CI. These responses were poor in terminally ill and hypovolemic patients; however, when the latter were given additional fluids, their responses were markedly improved. The hemodynamic effects of dobutamine are well known, but the DO2 and VO2 effects, which suggest improved tissue perfusion, have not been appreciated.     

Hemodynamic and metabolic effects of dobutamine in 18 patients after open heart surgery

Low cardiac output syndrome frequently follows cardiopulmonary bypass (CPB) surgery. In the present study, we used dobutamine to increase cardiac index (CI) and oxygen delivery (DO2) in 18 patients after open heart surgery. Using increasing doses of dobutamine up to 10 micrograms/kg.min-1, we observed statistically significant (p less than .01) increases in mean CI (2.50 +/- 0.10 to 3.56 +/- 0.18 L/min.m2) and in mean heart rate (HR) (83 +/- 3 to 105 +/- 3 beat/min). Mean systemic vascular resistance index decreased significantly (p less than .01) in all patients (2271 +/- 101 to 1648 +/- 83 dyne.sec/cm5.m2). Pulmonary vascular resistance index did not change in the ten coronary artery bypass graft patients, but decreased significantly (p less than .01) in the eight valve replacement patients (561 +/- 98 to 421 +/- 79 dyne.sec/cm5.m2). Mean DO2 increased in all patients, although there was no concomitant increase in oxygen consumption (VO2) in four patients. We observed a significant (p less than .01) increase in mean VO2 in the remaining 14 patients (110 +/- 6 to 148 +/- 12 ml/min.m2), in spite of significant decreases in PaO2 and increases in right-to-left intrapulmonary shunting. Although increases in HR and ventricular arrhythmias may limit its use, dobutamine increases CI and DO2 in patients after CPB. In the present study, dobutamine's varying metabolic effect exemplifies the need for close monitoring of hemodynamic and metabolic variables when using vasoactive drugs in the postoperative period.     

Blood polymorphonuclear dysfunction in patients with alcoholic cirrhosis

Polymorphonuclear leucocyte function was investigated in twenty patients with alcoholic cirrhosis and three patients with cryptogenic cirrhosis. Bacterial ingestion, oxygen-dependent bactericidal capacity, and chemotactic response were measured. Serum dependent abnormalities were common; they included deficiencies of ingestion and of all subsequent oxygen-dependent metabolic events (three patients), all oxygen-dependent metabolic events (one patient), cytochrome c reduction and iodination deficiencies (six patients), isolated cytochrome c reduction deficiency (ten patients), and chemotactic deficiencies (fourteen out of eighteen patients). Serum-independent abnormalities were much less common; they included increased ingestion rate (four patients), decreased stimulated reduction of nitroblue tetrazolium (three patients), and decreased myeloperoxidase content (eight patients). Polymorphonuclear leucocyte abnormalities are frequent in cirrhosis and may account in part for increased susceptibility to infection in that disease.     

Hemodynamic effects of dobutamine in an intact animal model.

BACKGROUND AND METHODS: Actions of dobutamine at the beta 1, beta 2, and alpha 1 adrenoreceptors were studied in anesthetized dogs. Six animals received dobutamine (at infusion rates of 0 to 160 micrograms/kg/min) with and without beta-adrenergic receptor blockade. Five animals received phenylephrine (0 to 16 micrograms/kg/min), with and without concurrent dobutamine (20 micrograms/kg/min); this procedure was repeated in five animals after beta-blockade. RESULTS: Dobutamine (10 to 160 micrograms/kg/min) increased heart rate (HR), cardiac output, and left ventricular change in pressure over time, and decreased systemic vascular resistance. beta-blockade prevented only dobutamine-induced changes in HR. Mean arterial pressure (MAP), unaffected by dobutamine alone, decreased with concurrent beta-blockade. Phenylephrine (1 to 16 micrograms/kg/min)-induced increases in MAP were unaffected by dobutamine; with beta-blockade, phenylephrine reduced MAP. Dobutamine prevented a phenylephrine-induced increase in systemic vascular resistance, an effect eliminated by beta-adrenergic receptor blockade. CONCLUSIONS: Dobutamine appeared to be an agonist at the beta 1- and beta 2-adrenoreceptors and at the myocardial alpha-adrenoreceptor. Dobutamine appeared to be an alpha-adrenergic receptor antagonist in the peripheral vasculature.     

Plasma glutathione S-transferase measurements in patients with alcoholic cirrhosis

Hepatocellular damage has been assessed in 54 patients with biopsy proven alcoholic cirrhosis by measuring the activity of aspartate aminotransferase (AST) and the concentrations of glutathione S-transferase B1B1 (GST B1B1) and B2B2 (GST B2B2) in serum. The levels of AST, GST B1B1, or GST B2B2 were abnormal in 28, 28 and 17 patients respectively but abnormalities in AST and GST measurements appeared to identify different populations of patients.     

Pituitary-testicular function in patients with alcoholic cirrhosis of the liver

In forty-two patients with alcoholic liver cirrhosis and without recent alcohol ingestion the pituitary-testicular function was studied in an effort to relate the endocrine abnormalities with the degree of liver cell dysfunction, evaluated on a quantitative basis. Compared with values in twenty-one healthy controls, we found significantly elevated serum oestrone, oestradiol, follicle-stimulating hormone, luteinizing hormone and prolactin (P less than 0.01). Serum dehydro-epiandrosterone and dehydroepiandrosterone sulphate were significantly reduced in the cirrhotics (P less than 0.01), whereas serum testosterone was not significantly different from that in the controls. Raised levels of sex-hormone binding globulin were found in 71% (22/31) of the patients (median 8 x 10(-18) mol/l, range 3-17 x 10(-8) mol/l). The incidence of gynaecomastia (38%), cutaneous spiders (67%), testicular atrophy (24%) and reduced axillary hair (71%) was without significant relation to raised levels of sex-hormone binding globulin or progressively reduced liver function. In the presence of clinical or hormonal hypo-gonadism we found evidence of a state of primary hypogonadism together with an inadequate secretion of gonadotropins. The state of hyperoestrogenaemia and the concentration of gonadotropins were significantly correlated to the hepatic synthesis of coagulation factors.     

Haemodynamic response to exercise in patients with alcoholic liver cirrhosis

Summary. Physical work capacity was evaluated by a multistage bicycle exercise test in 29 patients, 22 men and seven women aged 35–61 years (mean 49) with alcoholic liver cirrhosis and in a sex- and age-matched control group. The maximal work load was reduced in the patient group, mean 122 vs. 186 watts in men (P < 0·001), and 60 vs. 119 watts in women (P < 0·005). Resting heart rate was higher in patients (91 vs. 78 beats × min¹, (P < 0·005), and the maximal heart rate was lower (159 vs. 170 beats × min^-1, (P < 0·001) compared with controls. Thirteen of 29 (45%) patients compared with 5 of 29 (17%) control subjects had an increase in left ventricular ejection fraction of ≤5% during exercise (P < 0·05). The present results suggest that an impaired capacity of the cardiac function to respond adequately to physical stress may at times contribute to the reduced physical work capacity seen in patients with alcoholic liver cirrhosis.     

酒精性肝硬化伴戒断综合征的护理干预研究

目的探讨酒精性肝硬化伴饮酒戒断综合征的有效护理干预方法。方法选择80例酒精性肝硬化伴饮酒戒断综合征患者,按随机数字表法随机分为对照组和干预组各40例,对照组在药物治疗的同时由护士对患者进行一般性指导,干预组则采取综合护理干预方法,通过量表调查对患者自我情绪改变、健康行为和生活质量角度进行测试和评定。结果干预组和对照组患者在自我情绪、健康行为和生活质量的改变方面具有统计学差异(P<0.01)。结论通过在护理上积极多方位整体干预,可使酒精性肝硬化伴饮酒戒断综合征患者以积极的心态应对并克服酒精戒断症状带来的负性心理情绪反应,从而提高治疗的依从性,明显改善肝功能。     

Pharmacokinetics and protein binding of cefpiramide in patients with alcoholic cirrhosis

The pharmacokinetics of cefpiramide, a new cephalosporin, were investigated after a single 1 gm intravenous injection in 11 patients with alcoholic cirrhosis and compared with those of 11 healthy subjects. In patients with cirrhosis the plasma elimination half-life was three times longer than that in normal subjects. The total plasma clearance was decreased significantly (p less than 0.001): 12.3 +/- 6.5 ml/min in patients and 25.6 +/- 4.6 ml/min in healthy volunteers, respectively. The urinary excretion of unchanged drug (percent of intravenous dose) for patients (69.8% +/- 29.9%) was statistically higher (p less than 0.01) than that for subjects (16.2% +/- 3.9%). The renal elimination became increasingly important with hepatic impairment. Protein binding of cefpiramide was reduced significantly in the group with cirrhosis. The average unbound fraction was 10.4% +/- 9.5% in patients with cirrhosis and 1.9% +/- 0.3% in normal subjects (p less than 0.01). Because the rate of elimination from plasma in patients is slower, the dosage regimen of cefpiramide would probably be modified in cirrhosis.     

Nature and quantity of fuels consumed in patients with alcoholic cirrhosis.

Although alcoholism is a leading cause of morbidity and mortality of middle-aged Americans, there are no data available pertaining to the consequences of Laennec's cirrhosis on total body energy requirements or mechanisms for maintaining fuel homeostasis in this patient population. Therefore, we simultaneously used the techniques of indirect calorimetry and tracer analyses of [14C]palmitate to measure the nature and quantity of fuels oxidized by patients with biopsy-proven alcoholic cirrhosis and compared the results with values obtained from health volunteers. Cirrhotic patients were studied after an overnight fast (10-12 h). Normal volunteers were studied after an overnight fast (12 h) or after a longer period of starvation (36-72 h). Total basal metabolic requirements were similar in overnight fasted cirrhotic patients (1.05 +/- 0.06 kcal/min per 1.73 m2), overnight fasted normal subjects (1.00 +/- 0.05 kcal/min per 1.73 m2), and 36-72-h fasted normal volunteers (1.10 +/- 0.06 kcal/min per 1.73 m2). Indirect calorimetry revealed that in cirrhotic patients the percentages of total calories derived from fat (69 +/- 3%), carbohydrate (13 +/- 2%), and protein (17 +/- 4%) were comparable to those found in 36-72-h fasted subjects, but were clearly different from those of overnight fasted normal individuals who derived 40 +/- 6, 39 +/- 4, and 21 +/- 2% from fat, carbohydrate, and protein, respectively. These data are strikingly similar to data obtained through tracer analyses of [14C]palmitate, which showed that in overnight fasted patients with alcoholic cirrhosis, 63 +/- 4% of their total CO2 production was derived from oxidation of 287 +/- 28 mumol free fatty acids (FFA)/min per 1.73 m2. In contrast, normal overnight fasted humans derived 34 +/- 6% of their total CO2 production from the oxidation of 147 +/- 25 mumol FFA/min per 1.73 m2. On the other hand, values obtained from the normal volunteers fasted 36-72 h were similar to the overnight fasted cirrhotic patients. These results show that after an overnight fast the caloric requirements of patients with alcoholic cirrhosis are normal, but the nature of fuels oxidized are similar to normal humans undergoing 2-3 d of total starvation. Thus, patients with alcoholic cirrhosis develop the catabolic state of starvation more rapidly than do normal humans. This disturbed but compensated pattern for maintaining fuel homeostasis may be partly responsible for the cachexia observed in some patients with alcoholic cirrhosis. This study also showed remarkably good agreement between the results obtained with indirect calorimetry and those obtained with 14C tracer analyses.     

Influence of portocaval anastomosis on lipid parameters in patients with alcoholic cirrhosis

The effect of portocaval shunt operation on lipid metabolism was investigated in 10 patients with alcoholic cirrhosis. Portocaval shunt operation resulted in a significant decrease of concentration of total serum cholesterol, total serum triglycerides, LDL cholesterol, VLDL cholesterol, VLDL triglycerides, and LCAT activity. The concentrations of free cholesterol, esterified cholesterol, phospholipids, LDL triglycerides, HDL cholesterol, and HDL triglycerides were unaffected.     

Systemic and microcirculatory effects of dobutamine in patients with septic shock

Purpose

The aim of this study was to characterize the cardiovascular responses to dobutamine and their predictors. Our hypotheses were that dobutamine mainly produces tachycardia and vasodilation and fails to improve the microcirculation of patients with septic shock.

Materials and Methods

Systemic hemodynamics and sublingual microcirculation were evaluated with dobutamine (0, 2.5, 5.0, and 10.0 μg kg^− 1 min^− 1) in 23 patients with septic shock.

Results

Dobutamine increased heart rate, cardiac index, and stroke volume index (SVI). Mean blood pressure was unchanged, and systemic vascular resistance decreased. Individual responses were heterogeneous. Stroke volume index increased in 52% of the patients. These patients showed lower changes in mean blood pressure (3 ± 16 mm Hg vs − 10 ± 6 mm Hg, P < .05) and higher increases in cardiac index (1.47 ± 0.93 L m^− 1 m^− 2 vs 0.20 ± 0.5 L m^− 1 m^− 2) than did nonresponders. Changes in SVI significantly correlated with echocardiographic left ventricular ejection fraction (r = 0.55). In the whole group, perfused capillary density remained unchanged (14.0 ± 4.3 mm/mm² vs 14.8 ± 3.7 mm/mm²), but improved if basal values were 12 mm/mm² or less (9.1 ± 4.3 mm/mm² vs 12.5 ± 4.8 mm/mm²).

Conclusions

Dobutamine produced variable hemodynamic effects. Systolic dysfunction was the only variable associated with increases in SVI. Finally, dobutamine only improved sublingual microcirculation when severe alterations were found at baseline.     

Spontaneous bacterial peritonitis in alcoholic cirrhosis with ascites

Taking part in recreation or tourist pursuits far from medical resources can tax the ingenuity of even the best-prepared wilderness traveler. In part 1 of this three-part article, which appeared in the June issue, means of preventing illness and injury in the “wilds” were discussed. This part outlines the specific management of several illnesses and injuries that might occur on the trail. In part 3, to appear in August, items for inclusion in a medical kit for wilderness travel will be detailed.