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At least 19 recordsLinked to original sources

Left heart assist device: early clinical experiences with management of postperfusion low cardiac output.

Low cardiac output is a continuing cause of mortality after intracardiac operation in patients coming to surgery with advanced myocardial dysfunction. A simple method using a left heart assist device (LHAD) after open heart surgery to manage low cardiac output resistant to all adjuvant therapy is described. Except for the special cannulas, all equipment necessary for the LHAD is available in any unit performing open-heart surgery. Fifteen patients who could not be separated from conventional cardiopulmonary bypass underwent postoperative support with the LHAD (up to 501 hours). Ten patients were weaned from the device and 6 were dismissed from the hospital. Four patients remain alive, the longest period after operation being 24 months. A major asset of the LHAD is that thoracic reentry is not required at termination of LHAD support, since their design permits the cannulas to remain permanently in situ. This is thought to be an important concept, since critically ill patients requiring support are precisely those in whom added risk would be imposed by a second operation.

Adult↗

Gastric intramucosal pH: a predictor of survival in cardiac surgery patients with low cardiac output?

OBJECTIVE: To assess the value of gastric intramucosal pH measurement in patients with low output after cardiac surgery. DESIGN: Prospective clinical study. SETTING: University hospital. PARTICIPANTS: Fifteen patients with low output after cardiac surgery were included. Those who survived the first postoperative day (n = 14) remained in the study. INTERVENTIONS: Gastric intramucosal pH and arterial lactate concentrations were measured 6, 12, and 24 hours after admission to the intensive care unit. Intravenous infusion of buffer solutions was strictly avoided during the equilibration period and in the half hour before injection of saline into the gastric balloon of the tonometer. MEASUREMENTS AND MAIN RESULTS: Eight patients survived during the 28-day observation period, and six patients died. On admission to the intensive care unit, no difference in cardiac index (1.56 v 1.54 L/min/m2) or pulmonary capillary wedge pressure (17.3 v 17.7 mmHg) was found between survivors and nonsurvivors. During the first 24 hours after surgery, arterial lactate was significantly higher in the nonsurvivor group (61 v 23 mg/dL), but there was no difference between the gastric intramucosal pH of survivors and nonsurvivors (7.41 v 7.42 on admission). CONCLUSIONS: Calculated gastric mucosal pH is not an early predictor of survival in cardiac surgery patients with postoperative low cardiac output syndrome. Further studies are required to assess whether the gradient between arterial and intramucosal partial pressure of carbon dioxide (PCO2) might be a more useful predictive value.

Adult↗

Comparison of the use of a propofol infusion in cardiac surgical patients with normal and low cardiac output states.

OBJECTIVES: This study compared the hemodynamic effects of a propofol infusion with fentanyl analgesia in patients undergoing cardiac surgery with normal and low cardiac output states. Low cardiac output was defined as a cardiac index less than 2.5 L/min/m2 with a minimum pulmonary capillary wedge pressure of 7 mmHg. DESIGN: A prospective and open study. SETTING: A single center cardiothoracic unit within a teaching hospital. PARTICIPANTS: Patients were assigned to group P, poor cardiac output or group N, normal cardiac output, after thermodilution pulmonary artery catheter assessments. INTERVENTIONS: Both groups received a propofol infusion, 8 mg/kg/hr, until induction of anesthesia, followed by 4 mg/kg/hr until the intensive care unit. Fentanyl, 15 micrograms/kg, and pancuronium, 0.15 mg/kg, were administered after induction. The lungs were ventilated with oxygen. MEASUREMENTS AND MAIN RESULTS: Hemodynamic assessments were repeated at intervals until cardiopulmonary bypass. Changes within and between groups were compared using t tests on percentage change from baseline. Group N had significantly greater decreases in cardiac index, stroke volume, and left ventricular stroke work index than group P. There were comparable decreases in mean arterial pressure on induction of anesthesia, 14% and 8% in group N and group P, respectively. In both groups, right ventricular ejection fraction was unchanged. CONCLUSIONS: The use of a propofol infusion for induction and maintenance of anesthesia in patients with low cardiac output states undergoing cardiac surgery is not contraindicated.

Analgesics, Opioid↗

Effects of variable dose milrinone in patients with low cardiac output after cardiac surgery. European Multicenter Trial Group.

We studied 99 adult patients after elective cardiac surgery who had low cardiac output (cardiac index less than 2.5 L/min/m2) in spite of adequate cardiac filling pressure (pulmonary capillary wedge pressure less than 8 mm Hg). Patients received milrinone by loading dose (50 micrograms/kg over a 10-minute period), followed by a continuous infusion of either 0.375, 0.5, or 0.75 micrograms/kg/min (low-, middle-, and high-dose groups, respectively) given for a minimum of 12 hours. Patients were allocated to each dosage group sequentially, not randomly. Hemodynamic measurements were made before the loading dose and at 15, 30, 45, and 60 minutes, 3, 6, and 12 hours after the start of milrinone therapy. Further measurements were made at 2 and 4 hours after treatment was stopped. Milrinone therapy was associated with a rapid, well-sustained, and highly significant increase in cardiac index in all three dose groups (p less than 0.001), and a similar fall occurred in pulmonary capillary wedge pressure in all groups (p less than 0.001). Significant increases occurred in heart rate in all three groups (p less than 0.001). Systemic and pulmonary vascular resistance also fell significantly, although changes in this latter parameter were less predictable and more dose dependent. Few serious treatment-related adverse effects were seen. We conclude that intravenous milrinone is an effective and safe therapy for the treatment of low output states after cardiac surgery.

Cardiac Output↗

Agreement and clinical utility of 2 techniques for measuring cardiac output in patients with low cardiac output.

BACKGROUND: The reliability of cardiac output obtained with the bolus technique is a problem. OBJECTIVES: To compare measurements of cardiac output measured with bolus and continuous techniques in patients with low cardiac output and to determine if measurements obtained with the continuous technique increased the number of subsequent clinical decisions. METHODS: In 60 intensive care patients, a nurse recorded a single continuous cardiac output measurement and then obtained the mean of 3 consecutive bolus determinations. The medical records of these 60 patients (experimental group) for the next 48 hours and of 60 other patients with regular or mixed venous oximetry catheters (control group) were reviewed to assess the occurrence of cardiac output events and the frequency of clinical decisions based on the events. RESULTS: Mean cardiac output was 4.46 L/min by the continuous technique and 5.20 L/min by the bolus technique (P = .011) for the experimental group. Median bias between the 2 types of measurements was -0.10 L/min (P = .79). Twenty-three of the pairs (38%) had an absolute percent difference greater than 15%. Of these, 18 (78%) had a higher bolus reading. Treatment decisions per 48 hours were 9.9 for the experimental group and 8.6 for the control group (P = .014). Median length of stay was 2 days less in the experimental group (P = .02), and mean highest cardiac output was 0.81 L/min higher (P = .009). CONCLUSIONS: Measurements of cardiac output determined with the continuous technique may be more precise than measurements determined with the bolus technique. Continuous cardiac output information increases the number of treatment decisions and actions that may shorten hospital length of stay.

Cardiac Output↗

[Treatment of low cardiac output following extracorporeal circulation with captopril].

Seven patients in low-output cardiac failure, resistant to conventional vasodilators and inotropic agents, following surgery with extra-corporeal circulation were given oral captopril, an angiotensin converting enzyme inhibitor. The effects of captopril on haemodynamic and renal function were studied after 2, 6, 12 and 24 hours of treatment. After two hours, there was a mean reduction in systemic arterial resistance of 29%, in pulmonary arterial resistance of 18% and in pulmonary wedge pressure of 15%. The mean increase in the cardiac index was 28%. This marked initial haemodynamic improvement was either maintained or increased over the rest of the 24 hours. By 24 hours there had been a mean increase in urinary sodium excretion of 200%. The urinary sodium/potassium ratio increased from 0.62 to 1.45. Oral captopril thus seems suitable for treating low-output cardiac failure following surgery requiring extra-corporeal circulation.

Adult↗

Low cardiac output following cardiac surgery: critical thinking steps.

Patients often experience low cardiac output following cardiac surgery and as many as 90% of patients experience a decreased left ventricular ejection fraction (LVEF) and cardiac index (CI). Causes may vary from volume depletion to global myocardial dysfunction. Critical thinking skills, combined with diligent patient monitoring and a knowledge of cardiovascular physiology and pharmacology are required for prompt recognition and treatment of low cardiac output following cardiac surgery.

Aged↗

[Peritoneal dialysis in the treatment of the low cardiac output after extracorporeal circulation].

Low cardiac output after cardiopulmonary bypass is not uncommon. This per- and postoperative cardiac depression is accompanied by an impairment of renal function, which recovers with the improvement of the low cardiac output. These two correlated failures may become resistant to cardiotonic and diuretic drugs. Indeed the fluid balance is strongly disturbed, although venous pressure is only moderately increased. The only possible treatment could be water withdrawal. Nine patients are reported, all suffering from cardiac and renal failure after cardiopulmonary bypass. They were successfully treated with the method of continuous ambulatory peritoneal dialysis. This method allowed us to stop all intravenous cardiac drugs within 36 h, whilst diuresis reappeared together with a better efficacy of diuretic drugs. This beneficial haemodynamic effect of water withdrawal is discussed. This phenomenon may be related to an influence of right ventricular filling on the left ventricle. Low cardiac output may occur as a result of septal displacement, especially if there is concomitant myocardial suffering. Withdrawing a small volume of water may have modified the septal displacement, and improved cardiac output. Continuous ambulatory peritoneal dialysis was simple and well tolerated; it seemed to have contributed to the haemodynamic recovery of all the nine patients.

Aged↗

Relationship between renin activity and aldosterone release in the patients with low cardiac output syndrome after open cardiac surgery.

Plasma renin activity and aldosterone concentration were measured by radioimmunoassay technique in seven patients with low cardiac output syndrome after open cardiac surgery. Plasma renin activity and aldosterone concentration markedly increased, and plasma renin activity was well correlated with plasma aldosterone concentration. Plasma renin activity and aldosterone concentration, however, had no direct correlation with plasma sodium and potassium concentration or administered doses of inotropic agent, potassium and diuretic. Sodium and potassium balance was closely correlated with plasma aldosterone concentration. In the present study, it was suggested that the secondary hyperaldosteronism following low cardiac output syndrome after open cardiac surgery was mainly induced by the increased release of renin and that it influenced on the balance of sodium and potassium metabolism under such disturbed circulatory circumstances.

Adolescent↗

Haemodynamic and biological effects of intravenous milrinone in patients with a low cardiac output syndrome following cardiac surgery: multicentre study.

The haemodynamic and biological effects of intravenous milrinone were studied in 24 adult patients with a low cardiac output syndrome following cardiac surgery. The patients received a milrinone bolus of 50 micrograms kg-1 over 10 min followed by a 0.375-0.750 micrograms kg-1 min-1 infusion over 48 h. After the first hour of treatment, an increase in cardiac index, systolic index and left ventricular stroke work index, and a decrease in right and left loading pressures, pulmonary artery pressure, systemic vascular resistance and pulmonary vascular resistance were observed while heart rate and systemic arterial pressure were not modified. These haemodynamic effects were maintained over the 48 h of treatment and persisted 3 h after discontinuation of treatment. Milrinone, which possesses inotropic and vasodilatory effects, increased cardiac performance and corrected the low cardiac output in all patients.

Adult↗

[Comparison of enoximone versus tobutamine in the treatment of low cardiac output after cardiac surgery].

Enoximone, a new cardiotonic agent not related to glycosides or catecholamines, has been suggested for treatment of low cardiac output syndromes occurring after cardiopulmonary bypass (CPB). The aim of the present study was to compare enoximone with dobutamine in the management of such cases. Twenty consecutive patients who had undergone cardiac surgery with CPB and who had a cardiac index (CI) less than 2.5 l.min-1.m-2, pulmonary capillary wedge pressure greater than 12 mmHg, and no renal failure, were randomly assigned to receive either enoximone (group E, n = 10) or dobutamine (group D, n = 10). The following parameters were monitored at baseline, 15, 30, 60, 90 min, 2, 6, 10 and 14 h: arterial, central venous, pulmonary arterial and capillary wedge pressures (PCWP), cardiac index (CI), stroke volume index (SVI), stroke work index (SWI), systemic (SVR) and pulmonary vascular resistances, as well as heart rate-pressure product (HRPP). Patients in group E were given a bolus of 0.5-1 mg.kg-1 enoximone over a 20 min period, followed by a continuous infusion of 2-20 micrograms.kg-1.min-1, depending on clinical response. In group D, patients were given 2.5 to 15 micrograms.kg-1.min-1 dobutamine according to clinical response. No other inotropic drug was used during the study period. The aim was to obtain an increase in CI greater than or equal to 30% at the end of the first hour of treatment. Excessive systemic hypotension with low SVR was treated with volume loading.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Clinical and haemodynamic effects of milrinone in the treatment of low cardiac output after cardiac surgery.

We have studied the haemodynamic effects of i.v. milrinone, a new phosphodiesterase inhibitor, in patients with low cardiac output after cardiac surgery. Thirty-five patients with a cardiac index (Cl) less than 2.5 litre min-1 m-2 and a pulmonary capillary wedge pressure (PCWP) greater than 8 mm Hg were given a loading dose of milrinone 50 micrograms kg-1 followed by an infusion at one of three rates: 0.375 micrograms kg-1 min-1, 0.5 micrograms kg-1 min-1 or 0.75 micrograms kg-1 min-1 for 12 h. After 1 h there were increases in Cl (35%) (P less than 0.001), heart rate (13%) (P less than 0.01) and stroke volume index (19%) (P less than 0.005). There were decreases in mean arterial pressure (12%) (P less than 0.01), systemic vascular resistance (35%) (P less than 0.001) and PCWP (24%) (P less than 0.05). Pulmonary vascular resistance was unchanged or reduced and left ventricular stroke work index was unchanged or increased. The haemodynamic improvements were sustained throughout the infusion period. Milrinone was tolerated well: three patients developed tachycardia greater than 125 beat min-1, one patient developed atrial fibrillation and one patient had a short run of atrial bigemini. We conclude that milrinone is a useful agent in the treatment of patients with a reduced cardiac output after cardiac surgery.

Adult↗

A bolus dose of 1.5 mg/kg amrinone effectively improves low cardiac output state following separation from cardiopulmonary bypass in cardiac surgical patients.

BACKGROUND: The aim of this study was to evaluate the efficacy of 1.5 mg/kg bolus of amrinone on low cardiac output (CO) state following emergence from cardiopulmonary bypass (CPB) in cardiac surgical patients. METHODS: Immediately after emergency from CPB, 14 patients with a cardiac index (CI) less than 2.2 l.min-1.m-2 despite administration of inotropes and nitroglycerin, received 1.5 mg/kg amrinone over 3 min without changing catecholamine infusion rates (amrinone group). Hemodynamics and left ventricular short axis views with transesophageal echocardiography were recorded at baseline, 3, 4, and 10 min following amrinone administration. Left ventricular filling volumes were maintained constant by volume reinfusion from the CPB reservoir. We matched the data of the amrinone group with the other 14 patients who did not receive amrinone (non-amrinone group) to evaluate the efficacy of amrinone in low CO state. RESULTS: At baseline, CI (1.8 +/- 0.1 l.min-1.m-2) in the amrinone group was significantly lower than CI (3.0 +/- 0.2) in the non-amrinone group. Following amrinone administration, CI and velocity of circumferential fibershortening corrected for heart rate (Vcfc) significantly increased, and systemic vascular resistance index and pulmonary vascular resistance index significantly decreased from the baseline within 10 min without changes in heart rate, mean arterial blood pressure, or pulmonary artery occlusion pressure, and became equivalent with those of the non-amrinone group. CONCLUSIONS: A 1.5 mg/kg amrinone loading dose to patients in a low CO state, despite catecholamine therapy immediately after emergence from CPB, effectively improves ventricular function when loading conditions are maintained constant.

Adult↗

Propofol and fentanyl anaesthesia for patients with low cardiac output state undergoing cardiac surgery: comparison with high-dose fentanyl anaesthesia.

We have compared the haemodynamic effects of an infusion of propofol 8 mg kg-1 h-1 followed by 4 mg kg-1 h-1 and fentanyl 15 micrograms kg-1 (group 1) with midazolam 3-6 mg and fentanyl 60 micrograms kg-1 (group 2) in patients with a low cardiac output state undergoing cardiac surgery. Heart rate was lower in group 1 throughout the period before cardiopulmonary bypass. There were no significant differences between the groups in other measured variables. Arterial pressure decreased in both groups after induction, by 21% in group 1 and 18% in group 2. Thermodilution assessment of right ventricular ejection fraction was unchanged. Myocardial contractility was not affected adversely. Patients in group 1 who received an infusion of propofol and a smaller dose of fentanyl awakened sooner and the trachea was extubated earlier.

Adult↗

[Pharmacological correction of low cardiac output syndrome in hemofiltration].

Low cardiac output was corrected by catecholamines in the course of hemofiltration (HF) administered to 37 patients with multiple organ failure after surgery. Catecholamines (adrenaline hydrochloride, noradrenaline hydrotartrate, dopamine hydrochloride, and dobutamine hydrochloride) were used as monotherapy or in various combinations (two, three, or four drugs). Ninety percent of patients with low cardiac output subjected to HF were administered combined catecholamine therapy. Catecholamines provided the hemodynamic stability of HF in patients with low cardiac output. The frequency of noradrenaline administrations and its mean doses were reliably decreased in the course of HF, whereas the mean doses of adrenaline, dopamine, and dobutamine remained virtually the same.

Cardiac Output, Low↗

Pharmacologic support for postoperative low cardiac output.

This review has outlined a rational approach to the understanding and pharmacologic treatment of low output states after cardiac surgery. There are clearly other reasonable schemes for the use of these agents for management of these difficult patients. However, the principles of management remain the same. Data about the specific effects of these drugs must be applied to specific patients whose particular hemodynamic derangements have been analyzed carefully. However, the complex and changing interactions between the heart and the peripheral vascular system and the effects of these agents on both signify that these analyses must be made continuously during the early hours after cardiac surgery. Rational use of these agents requires careful analysis of the specific hemodynamic disorder in a given patient. Pharmacologic inotropic therapy should then be tailored to these abnormalities and based on what is known about the expected effects of these drugs on the heart and peripheral circulation. Careful and repeated follow-up measurements to document both the effects of the drugs and potential changes in the patient's hemodynamic state are required if successful therapy is to be achieved. A rational approach to the selection of the inotropic agents requires not only an understanding of the effects of the drugs, but continuous monitoring of the patient's hemodynamic state and recognition that the patient's condition and needs may change and dictate alteration in subsequent therapy.

Cardiac Output, Low↗

Comparative effects of combined dopamine and nitroprusside versus dobutamine and nitroprusside infusions for computer-controlled management of low-output cardiac failure after open heart surgery.

In order to evaluate the possible differences in response to two currently preferable inotropic-vasodilator drug combinations, the hemodynamic effects of automated infusions of nitroprusside-dobutamine and nitroprusside-dopamine were studied in two clinically similar groups of patients with low-output syndrome after aorto-coronary bypass surgery. Nitroprusside, when infused in combination with dopamine, was effective in lowering filling pressures of both ventricles and systemic and pulmonary arterial pressures reflecting the reversal of deleterious rise of these parameters including determinants of myocardial oxygen consumption (mean arterial pressure rate by +6%, heart rate by +20%) caused by dopamine (6 micrograms/kg/min) infused alone. The combination of the more cardioselective catecholamine dobutamine with nitroprusside brought about similar increase in cardiac output by 50%, but derived its hemodynamic efficiency from the sum of separate effects of components and produced less in the way of elevation of determinants of oxygen consumption. Dobutamine when infused alone (6 micrograms/kg/min) has not affected systemic and pulmonary arterial pressures and stroke index rose more markedly (+9%) as a result of more moderate heart rate increase (+13%). Nitroprusside contributed in an additive manner to the achieved overall reduction of SVR and PVR by 43% and 50%, resp., the automated infusion being helpful in maintaining these values within close tolerances.

Cardiac Output, Low↗

Continuous extracorporeal fluid removal in children with low cardiac output after cardiac operations.

Eleven hypervolemic and oliguric children with low cardiac output after cardiac operations were treated by slow continuous ultrafiltration or continuous arteriovenous hemofiltration. A mean negative fluid balance of 1.63 +/- 0.37 ml/kg/hr (standard error of the mean [SEM]) significantly improved the hemodynamic status within 59 +/- 6.1 hours (SEM). Although the central venous pressure decreased significantly from 15.2 +/- 0.84 to 8.8 +/- 0.92 mm Hg (p less than 0.0001), the mean arterial pressure increased significantly from 41.5 +/- 2.54 to 53.5 +/- 2.21 mm Hg (p less than 0.001). In addition, pH increased significantly from 7.31 +/- 0.01 (SEM) to 7.43 +/- 0.001 (SEM) (p less than 0.001) and oxygenation index (arterial oxygen tension/inspired oxygen fraction) from 119 +/- 15.2 (SEM) to 214 +/- 27.0 (SEM) (p less than 0.001). Hemodynamic improvement during slow continuous extracorporeal fluid removal allowed a significant decrease of the catecholamine infusion rate. After normovolemia had been achieved, continuous arteriovenous hemofiltration had to be continued in four children because of persistent anuria. Eight patients could be weaned from artificial ventilation and vasopressor support. Two patients died without recovery of renal function and one with restored renal function. Slow continuous ultrafiltration and continuous arteriovenous hemofiltration improve the cardiovascular function in children with low cardiac output by optimizing the preload conditions of the failing heart. In addition, they improve acid-base balance and pulmonary gas exchange.

Blood Pressure↗