Effectiveness of dopamine in patients with cardiogenic shock

Achieving Functional Outcomes after Surgical Management of Catastrophic Vasopressor-induced Limb Ischemia

Vasopressor-induced limb ischemia is an unfortunate complication that can occur in patients treated for septic shock. Current literature lacks surgical treatment recommendations for this condition, besides amputation. We describe various reconstructive surgeries and functional outcomes in patients treated surgically for vasopressor-induced limb ischemia.

Methods

We retrospectively reviewed patients who were treated for septic shock and developed vasopressor-induced limb ischemia at our tertiary referral academic medical center. We reviewed presentation, treatment, surgical outcomes, and long-term functional outcomes.

Results

We present three previously healthy patients who developed gangrene of multiple limbs following the use of vasopressors to treat septic shock. Each patient underwent amputations or limb salvage procedures.

Conclusions

Limb ischemia is a devastating complication that can occur after prolonged vasopressor use. The decision to proceed with limb salvage versus amputation of ischemic extremities should be tailored to the individual patient. The main objective should be for the patient to obtain optimal function and quality of life, regardless of the type of surgery.

Amputation of multiple limbs caused by use of inotropics: Case report, a report of 4 cases

RATIONALE

We present 4 cases of symmetrical peripheral gangrene (SPG) associated with use of inotropic agent to elevate blood pressure. SPG is a relatively rare phenomenon characterized by symmetrical distal ischemic damage that leads to gangrene of 2 or more sites in the absence of large blood vessel obstruction, where vasoconstriction rather than thrombosis is implicated as the underlying pathophysiology. We present 4 SPG cases of the multiple limbs amputation, associated with inevitable use of inotropic agents.

PATIENT CONCERNS

Inotropic agents including dopamine and norepinephrine are used frequently in the treatment of hypotension, and its effectiveness in treating shock is firmly established. However, it can be caused peripheral gangrene by prolonged administration of high dose inotropics, inducing the constant contraction of the peripheral blood vessels.

DIAGNOSIS

These 4 patients had different clinical histories and background factors, but each experienced sepsis. The level of amputation is determined by the line of demarcation in concert with considerations of the biomechanics of stump stability, weight bearing, and ambulation.

INTERVENTIONS

After recovering of general conditions and completion of demarcation, these 4 patients underwent the amputation of multiple limbs.(bilateral amputations of upper extremities or bilateral amputations of lower extremities).

OUTCOMES

In each patient, there was no additional amputation caused by extension of SPG, and the rehabilitation with appropriate orthosis was performed. Treatment of underlying disease were continued too.

LESSONS

It is important to alert the possibility of amputations, according to the use of inevitable inotropics. We recommended the careful use of the inotropic agents to the physicians in treating septic shock.

Four limb amputations due to peripheral gangrene from inotrope use - Case report and review of the literature

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Rare case of 4 limb amputations due to peripheral gangrene from inotrope use.

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Contributing factors include disseminated intravascular coagulation and septic shock.

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Differential diagnoses include symmetrical peripheral gangrene and purpura fulminans.

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Some therapeutic agents are beneficial for peripheral ischemia with dopamine use.

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Single-stage elective amputations led to satisfactory rehabilitation with prosthesis.

INTRODUCTION

We present a rare case of 4 limb amputations due to peripheral gangrene which resulted from the use of inotropes for septic shock.

PRESENTATION OF CASE

A 72-year-old woman with no past medical history presented with fever and pain in bilateral big toes. She was diagnosed with Streptococcal pneumoniae septicaemia and was started on broad spectrum antibiotics, dopamine and noradrenaline in the medical intensive care unit. She developed peripheral gangrene of all 4 extremities due to microvascular spasm from inotrope use and 4 limb amputations were performed electively in a single stage.

DISCUSSION

The gangrene was contributed by the presence of disseminated intravascular coagulation and septic shock. There was no evidence of an autoimmune disorder or vasculitis on laboratory investigations and tissue histology.

CONCLUSION

Microvascular spasm is a rare complication of inotrope use which may lead to extensive peripheral gangrene. Anecdotal reports of reversal agents have been discussed. Four limb amputations are a reasonable option especially if done in an elective setting after the gangrene has demarcated itself. Rehabilitation with prosthesis after 4 limb amputations can result in good functional outcome.

Inotropic agents and vasodilator strategies for acute myocardial infarction complicated by cardiogenic shock or low cardiac output syndrome

BACKGROUND

The recently published German-Austrian S3 Guideline for the treatment of infarct related cardiogenic shock (CS) revealed a lack of evidence for all recommended therapeutic measures.

OBJECTIVES

To determine the effects in terms of efficacy, efficiency and safety of cardiac care with inotropic agents and vasodilator strategies versus placebo or against each other for haemodynamic stabilisation following surgical treatment, interventional therapy (angioplasty, stent implantation) and conservative treatment (that is no revascularization) on mortality and morbidity in patients with acute myocardial infarction (AMI) complicated by CS or low cardiac output syndrome (LCOS).

SEARCH METHODS

We searched CENTRAL, MEDLINE (Ovid), EMBASE (Ovid) and ISI Web of Science, registers of ongoing trials and proceedings of conferences in January 2013. Reference lists were scanned and experts in the field were contacted to obtain further information. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials in patients with AMI complicated by CS or LCOS.

DATA COLLECTION AND ANALYSIS

Data collection and analysis were performed according to the published protocol. All trials were analysed individually. Hazard ratios (HRs) and odds ratios with 95% confidence intervals (CI) were extracted but not pooled because of high heterogeneity between the control group interventions.

MAIN RESULTS

Four eligible, very small studies were identified from a total of 4065 references. Three trials with high overall risk of bias compared levosimendan to standard treatment (enoximone or dobutamine) or placebo. Data from a total of 63 participants were included in our comparisons, 31 were treated with levosimendan and 32 served as controls. Levosimendan showed an imprecise survival benefit in comparison with enoximone based on a very small trial with 32 participants (HR 0.33; 95% CI 0.11 to 0.97). Results from the other similarly small trials were too imprecise to provide any meaningful information about the effect of levosimendan in comparison with dobutamine or placebo. Only small differences in haemodynamics, length of hospital stay and the frequency of major adverse cardiac events or adverse events overall were found between study groups.Only one small randomised controlled trial with three participants was found for vasodilator strategies (nitric oxide gas versus placebo) in AMI complicated by CS or LCOS. This study was too small to draw any conclusions on the effects on our key outcomes.

AUTHORS' CONCLUSIONS

At present there are no robust and convincing data to support a distinct inotropic or vasodilator drug based therapy as a superior solution to reduce mortality in haemodynamically unstable patients with CS or low cardiac output complicating AMI.

Usefulness of multiaxis echocardiography in assessment of the left ventricle in ischemic heart disease. A review

Echoventriculography, a multiaxis M-mode echocardiographic technique, was developed to examine in detail the regional wall motions of the left ventricle. The basic technical aspects and limitations are described, and experience is reviewed on 263 healthy subjects or patients with ischaemic heart disease. The reliability in detecting site and size of asynergic segments was excellent as related to electrocardiographic and thallium scintigraphic sites of acute infarction, and with left ventricular cineangiograms in chronic coronary heart disease. The correlation with pathologic anatomic size of infarct in 24 consecutive patients was r = 0.88 (p less than 0.001) when expressed by a percentage of the left ventricular horizontal circumference. 94% of 111 infarcted segments were correctly detected by echo; only the posteroseptal and the most lateral regions remain out of the methodological range. The method separated old infarct scars from fresh necrosis. Decreasing echo contraction index correlated with increasing severity of coronary obstructions in 43 patients studied for coronary artery surgery. In 15 infarct patients the M-mode technique was more sensitive than two-dimensional echocardiography in recording asynergic segments or endocardial echoes. The multiple segmental echoventriculographic index decreased parallel with clinical severity of acute infarction (r = -0.79, p less than 0.001; 30 patients). There was a 88% (p less than 0.01) concordance between the reduction of the ST segments (-30%) and the recovery of the mechanical function in the ischaemic myocardial segments (+26%) after beta blockade with pindolol in 22 patients with acute infarction. Methylprednisolone showed no improvement. With dopamine the left ventricular size decreased markedly (p less than 0.0005). Echoventriculography thus seems to be very informative in evaluation of chronic or acute left ventricular dysfunction, despite the rather demanding nature of the technique in practice.

Symmetrical peripheral gangrene

Symmetrical peripheral gangrene (SPG), seen in a wide variety of medical conditions presents as symmetrical gangrene of two or more extremities without large vessel obstruction or vasculitis. Fingers, and toes (rarely nose, ear lobes or genitilia) are affected. It may manifest unpredictably in conditions associated with sepsis, low output states, vasospastic conditions, myeloproliferative disorders or in hyperviscosity syndrome. It carries a high mortality rate with a very high frequency of multiple limb amputations in survivors. Disseminated intravascular coagulation (DIC) is seen in majority of cases of SPG. A more or less stereotyped clinical picture of SPG in spite of ever widening aetiological spectrum is suggestive of DIC as the final common pathway of its pathogenesis. Early recognition of acrocyanosis, quick reversal of DIC, effective management of the underlying condition, haemodynamic stabilization and (perhaps) anticoagulation with low dose heparin (300-500 iu/hour) may be helpful in arresting the progression of pre-gangrenous changes to frank gangrene. Vasopressors such as dopamine should be used judiciously in the presence of DIC. Development of acrocyanosis and increase in serum lactate levels may be indicative of impending SPG and the imperative need to treat DIC as well as the underlying condition.

Current treatment of cardiogenic shock

<zakljucak> S obzirom na izneto moglo bi se zakljuciti da je letalitet kod bolesnika sa kardiogenim sokom i dalje visok i iznosi od 50 do 80%. Patofiziologija soka ukljucuje jednu spiralu koja je okrenuta nadole. Ishemija izaziva miokardnu disfunkciju, koja zatim pogorsava ishemiju podrucja nefunkcionalnog, ali vijabilnog miokarda, a to doprinosi razvoju kardiogenog soka. Kljuc za uspeh je dobro organizovan pristup, brza dijagnoza i promptna terapija za odrzavanje arterijskog krvnog prtiska i minutnog volumena. Smanjenju smrtnosti doprinosi hitna srcana kateterizacija i revaskularizacija sa angioplastikom ili koronarnom operacijom i to je mozda sada jedina standardna terapija. U bolnicama koje ne primenjuju direktnu angioplastiku bila bi pozeljna hemodinamska potpora intraaortnom balon pumpom i tromboliticka terapija sa brzim transportom u ustanove koje mogu da urade PKA ili urgentnu revaskularizaciju miokarda, jer to u mnogome dovodi do smanjenja mortaliteta.

Parenteral inotropic support for advanced congestive heart failure

Parenterally administered positive inotropic agents remain an important component of the therapeutics of cardiac dysfunction and failure. Dobutamine, a catechol, remains the prototype of this drug group, but recently has been joined by the phosphodiesterase III inhibitor, milrinone. Compared with dobutamine, milrinone has greater vasodilating-unloading properties. The catecholamine, dopamine, is often used as a parenteral positive inotrope; but at moderate to high dose, it evokes considerable systemic vasoconstriction. At lower doses, dopamine appears to augment renal function. Levosimendan and toborinone, new compounds with several mechanisms of action, are under active clinical investigation and review for approval. Parenteral positive inotropic therapy is indicated for short-term (hours to days) treatment of cardiovascular decompensation secondary to ventricular systolic dysfunction, low-output heart failure. More prolonged or continuous infusion of one of these agents may be necessary as a "pharmacologic bridge" to cardiac transplantation, another definitive intervention, or more advanced, intense medical therapy. An occasional patient will require a continuous infusion via indwelling venous catheter and portable pump, simply to be able to be discharged from the hospital setting and function in the home environment. Intermittent parenteral inotropic therapy for chronic heart failure has provoked considerable controversy and passion among cardiologists and heart failure specialists; an attempt is made to present this topic in an objective manner.

Is renal dose dopamine protective or therapeutic? Yes

In conclusion, dopamine has the unique ability, compared with other catecholamines, to improve renal blood flow, glomerular filtration rate, sodium excretion, and creatinine clearance, independent of its cardiac effects. In addition, low-dose dopamine can decrease renal and systemic vascular resistance, suppress aldosterone secretion, and interact with atrial natriuretic factor. Because of these clinically significant properties, dopamine has been used successfully to improve and treat acute oliguric renal failure in a variety of clinical situations as just described. In addition, there were no adverse or toxic cardiac effects, such as tachyarrhythmias or hypertension, detected with low-dose dopamine in studies reviewed for this publication. By increasing renal and mesenteric vasodilation, dopamine has been shown to be beneficial in preserving renal function in cardiac surgery, vascular surgery, liver transplantation, contrast-induced nephropathy, hypertension, and pediatric patients. A therapeutic renal effect has been observed in patients with hepatorenal syndrome or severe ovarian hyperstimulation syndrome, in patients requiring vasopressors and IABP, and in selected cases of acute oliguric renal failure and shock. Furthermore, the combination of low-dose dopamine with furosemide or prostaglandin results in enhanced renal effects. Further investigation is necessary to evaluate the important and specific therapeutic role of low-dose dopamine through prospective, randomized, double-blind studies. Until those data are available, the plethora of clinical evidence supporting the ability of low-dose dopamine to augment renal function continues to grow. For those who are skeptical, we offer the following suggestion: "The obscure we see eventually, the obvious takes a little longer"--E.R. Murrow.

Catecholamines in critical care. The commonly used catecholamines: receptor and clinical profile, indications and dosages

The pharmacology, pattern of receptor activation and resulting clinical impact of the currently most widely used intravenous catecholamines are reviewed. A brief physiological description of the alpha, beta and dopaminergic receptors is used in order to explain the clinical effects of norepinephrine, epinephrine, isoproterenol, dopamine, dobutamine and dopexamine. Each drug is discussed separately according to receptor profile, indications, dosages and current application in critical care. Tables are provided for comparison of relative strengths of these drugs regarding receptor activation, haemodynamic effects, organ perfusion and recommended dosages. The use of combinations of catecholamines to meet a variety of circulatory demands is commented upon.

Evaluation of long-term oral levodopa therapy in chronic congestive heart failure

To evaluate the long-term effects of orally administered levodopa, 11 patients with chronic congestive heart failure (NYHA III-IV) were studied during maintenance therapy (30 +/- 1 days) and after withdrawal from levodopa. The daily levodopa dose was 4 g in six patients; because of side effects the levodopa dose was reduced to 2-3 g in the remaining patients. After withdrawal of levodopa, mean pulmonary capillary wedge pressure and mean right atrial pressure increased significantly (from 19 +/- 2 to 24 +/- 3 and from 7 +/- 2 to 9 +/- 2 mmHg, respectively). Effective renal plasma flow was 329 +/- 57 during levodopa therapy and decreased significantly to 252 +/- 27 ml/min after withdrawal of levodopa. The number of ventricular premature contractions and couplets increased during levodopa therapy and decreased again significantly after withdrawal of levodopa. No significant differences between on and off levodopa were observed in resting heart rate, arterial blood pressure, cardiac index, stroke work index, systemic vascular resistance, sodium and water excretion, or creatinine clearance. Seven patients improved on levodopa therapy by one NYHA class; four of these seven patients deteriorated again by one NYHA class after withdrawal of levodopa. Regarding both clinical and hemodynamic changes after withdrawal of levodopa, three patients were classified as responders to long-term levodopa therapy. All three responders received 4 g levodopa per day. Average dopamine plasma level was 5.3 +/- 0.8 ng/ml in the responder group and 2.0 +/- 0.5 ng/ml in the nonresponder group. Long-term administration of oral levodopa is associated with beneficial clinical and hemodynamic response in only a minority of patients with chronic congestive heart failure.

Is inotropic therapy appropriate for patients with chronic congestive heart failure? Or is the digitalis leaf withering?

The appropriateness of inotropic therapy in chronic heart failure was examined by critically reviewing five assumptions upon which this form of therapy has been justified. Only the first, that cardiac performance can be acutely improved by inotropic therapy, has been empirically proven. That such acute improvement is sustained appears to be true with non-catecholamine agents whereas the chronic haemodynamic efficacy of oral catecholamines remains in doubt. That any inotropic agent can improve exercise tolerance, make the patient feel better, or effect a change without deleteriously affecting the myocyte is very much in doubt. Thus, although the prospect of using powerful inotropic therapy in the patient with heart failure is theoretically appealing, its utility remains to be proven.

Acute haemodynamic and metabolic effects of dopexamine, a new dopaminergic receptor agonist, in patients with chronic heart failure

Dopexamine, a new compound with postjunctional dopamine receptor activating and beta adrenoceptor agonist properties, was given to 10 patients with chronic heart failure at diagnostic cardiac catheterisation to investigate its acute haemodynamic and metabolic effects. The drug was administered by intravenous infusion in three incremental doses and produced significant dose related increases in cardiac index, stroke volume index, and heart rate and falls in systemic vascular resistance and left ventricular end diastolic pressure; aortic and pulmonary artery pressures were unchanged. Isovolumic phase (max dP/dt and KVmax) and ejection phase (peak aortic blood velocity, maximum acceleration of blood, and maximum rate of change of power with time during ejection) indices of myocardial contractility were all increased by dopexamine but these changes were hard to interpret in the presence of an increase in heart rate. Myocardial efficiency and ejection fraction were both increased and left ventricular end diastolic and end systolic volumes fell. These largely beneficial changes were achieved without a statistically significant increase in myocardial oxygen consumption or disturbance of myocardial metabolic function. Dopexamine was well tolerated but tremor was reported by two patients at the intermediate dose and mild chest pain by two patients at the high dose.

The effects of dopamine on central hemodynamics and myocardial metabolism in experimental propoxyphene-induced shock

The hemodynamic and cardiometabolic effects of dopamine were evaluated in propoxyphene-induced circulatory shock in eight pentobarbital anesthetized pigs. Circulatory shock was induced by an infusion of propoxyphene chloride 15 mg . min-1 i.v. At shock, i.e. CI less than or equal to 2.0 l . min-1 . m-2 and/or MAP less than or equal to 60 mmHg, dopamine was infused at 10, 20, 40, 80 and 160 micrograms . kg-1 . min-1 with an interval between increments of 8 min. After 30 min at 160 micrograms . kg-1 . min-1, the infusion rate was reversibly decreased. The propoxyphene infusion of 15 mg . min-1 was continued throughout the study. Dopamine improved the circulation in seven animals; one animal died in refractory shock during dopamine infusion. Dopamine infusion at shock level resulted in an increase of the following variables (% of baseline value): MAP (69%), HR (109%), CI (138%) and SVI (129%). Normalisation was seen in MRAP (120%) and in MPAOP (100%). A profound decrease in systemic vascular resistance was unchanged. Increases were seen in left and right ventricular stroke work index, to 88% and 176% of baseline, respectively. Left ventricular dP/dt increased (170%). In the coronary circulation myocardial blood flow increased (133%) as did myocardial oxygen consumption (65%) concomitant with a decrease in myocardial oxygen uptake (41%), but coronary vascular resistance progressively decreased (38%). The myocardial propoxyphene extraction changed from +54% to -86% during peak dopamine infusion. In conclusion, dopamine reversed cardiac failure in propoxyphene overdose by a marked positive inotropic stimulation restoring contractility. A marked positive chronotropic stimulation maintained a sufficient cardiac index and a normal blood pressure in spite of a profound vasodilatation which was unresponsive to dopamine.

New concepts and drugs in the treatment of congestive heart failure

This article seeks to make clear the basic differences in the treatment of heart failure between therapeutic maneuvers that are aimed at improving the mechanical loading conditions of the heart and those that are aimed at augmenting the fundamental contractile or inotropic state of the myocardium. Emphasis is placed on recognizing that treatment expectations must be viewed within an age- or maturity-dependent framework, since a diminished margin of cardiocirculatory reserve exists in the smallest and youngest patients that limits the extent of benefit that may be derived from diverse treatment approaches.

Correlation between the pharmacokinetics and pharmacodynamics of dopamine in healthy subjects

The pharmacokinetics and the pharmacodynamic action of dopamine were investigated in 5 healthy subjects. Dopamine was given in different doses (200, 400 and 800 micrograms/min) by constant intravenous infusion over 90 min. In order to control the influence of the procedure on the measured parameters the subjects also received a similar infusion of saline. Dopamine, noradrenaline and adrenaline levels in plasma were followed for up to 6 h after the infusion, and arterial pressure and heart rate were monitored. Dopamine reached a steady state level within 15 to 30 min after commencement of the infusion; the steady state levels averaged 36.5 micrograms/l at 200 micrograms/min, 73.8 micrograms/l at 400 micrograms/min and 207 micrograms/l at 800 micrograms/min. The corresponding total clearances were 5.81/ min, 5.51/min and 3.91/min suggesting non-linear kinetics. The kinetics could not be described by compartmental model. Noradrenaline and adrenaline levels were found to be elevated during infusion of dopamine. Noradrenaline had returned to its pretreatment level within 15 to 30 min after cessation of the infusion, whereas the adrenaline level did not return to the pretreatment value within the observation period. Heart rate was increased by the dose of 400 micrograms/min, and the systolic and mean arterial pressures were elevated, whereas distolic blood pressure remained unchanged. Elevated systolic blood pressure was better correlated with plasma dopamine than with noradrenaline concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Response of reperfusion-salvaged, stunned myocardium to inotropic stimulation

The purpose of this study was to determine whether myocardium salvaged by reperfusion following coronary occlusion could respond to inotropic stimulation by dopamine. Mongrel dogs underwent a 2-hour occlusion of the proximal left anterior descending coronary artery, followed by reperfusion for 5 or 28 hours. Dopamine (5 to 10 micrograms/kg/min) or dextrose was administered 1 hour or 24 hours after the onset of reperfusion. Serial, computer-assisted, two-dimensional echocardiographic determination of percentage of systolic wall thickening (%SWT) and cross-sectional ejection fraction (% delta area) were used to evaluate the response to treatment. Myocardium in the region of central ischemia contracted poorly after 1 hour of reperfusion (mean %SWT = 1.3 +/- 13.3% [mean +/- SD] compared to preocclusion value of 43.6 +/- 18.5%, p less than 0.001) and tended to thin at 24 hours of reperfusion (mean %SWT = -6.0 +/- 12.3%, p less than 0.001). After 1 hour of reperfusion, dopamine produced a greater than fourfold improvement in %SWT within the reperfused zone (to 15.3 +/- 7.3%, p less than 0.05). After 24 hours of reperfusion, dopamine again produced an improvement in %SWT (to 5.8 +/- 12.5%, p less than 0.05). There were no significant changes in %SWT with dextrose infusion. Thus, dopamine stimulates the reperfusion-salvaged but noncontracting (stunned) myocardium to contract as early as 1 hour after reperfusion.

Acute inotropic stimulation with dopamine in severe congestive heart failure: beneficial hemodynamic effect at rest but not during maximal exercise

Hemodynamic and metabolic effects of dopamine were studied at rest and during maximal exercise in 13 patients with severe chronic congestive heart failure (CHF). During exercise before the administration of dopamine, the stroke volume index increased from 17.1 +/- 5.2 ml/m2 at rest to 28.1 +/- 10.9 ml/m2 (p less than 0.001) at exhaustion, while pulmonary capillary wedge (PCW) pressure increased from 22.7 +/- 12.7 to 43.9 +/- 11.9 mm Hg (p less than 0.001). The arteriovenous oxygen difference increased from 8.9 +/- 2.3 ml/100 ml to 12.4 +/- 2.0 ml/100 ml (p less than 0.001) and oxygen uptake increased from 3.5 +/- 0.6 0.6 to 11.9 +/- 2.5 ml/kg/min (p less than 0.001). At rest, dopamine increased the stroke volume index to 23.3 +/- 8.1 ml/m2 (p less than 0.001) and reduced the PCW pressure to 20.5 +/- 1.1 mm Hg (p less than 0.05). However, during maximal exercise, the stroke volume index and PCW pressure were not changed by dopamine: 28.1 +/- 10.9 versus 28.6 +/- 10.2 ml/m2 (difference not significant [NS]) and 43.9 +/- 11.9 versus 42.5 +/- 11.2 mm Hg (NS), respectively. In contrast, the maximal heart rate achieved during exercise was significantly higher with dopamine, 140.3 +/- 29.3 versus 136.0 +/- 29.7 beats/min (p less than 0.05), which contributed to a slight augmentation in the maximal cardiac index, 3.82 +/- 1.13 versus 3.64 +/- 1.17 liters/min/m2 (p less than 0.05). Nonetheless, neither peak arteriovenous oxygen difference nor maximal oxygen uptake were significantly changed by dopamine.(ABSTRACT TRUNCATED AT 250 WORDS)

The hemodynamic response to dopamine and nitroprusside following right atrium-pulmonary artery bypass (Fontan procedure)

Cardiac output is critically dependent upon pulmonary vascular resistance after right atrium-pulmonary artery bypass (Fontan procedure), since there is no pulmonary ventricle in the circulation. Inotropic agents, including dopamine, may increase pulmonary vascular resistance and, therefore, might have an adverse effect on cardiac output. The present study determined the hemodynamic responses to dopamine and nitroprusside of 9 patients following right atrium-pulmonary artery bypass. Particular attention was given to effects on cardiac output (CI), pulmonary vascular resistance, and right atrial pressure (RAP). Baseline hemodynamic data were measured without drugs, with dopamine at 7.5 micrograms/kg/min, with sodium nitroprusside up to 5.0 micrograms/kg/min, and with a combination of dopamine, 7.5 micrograms/kg/min, and sodium nitroprusside, 1.0 micrograms/kg/min. Right and left atrial pressures (LAP), mean arterial blood pressure (BP), heart rate (HR), and CI were measured. Stroke volume index and pulmonary arteriolar resistance index were calculated. The increase in CI from baseline (1.98 +/- 0.86 liters per minute) was significant for infusions of dopamine (2.75 +/- 1.05, p less than 0.001), sodium nitroprusside (2.57 +/- 0.78, p less than 0.001), and both drugs (2.74 +/- 0.84, p less than 0.001). The increased CI was achieved primarily by a significant increase in HR with dopamine and by an increase in stroke volume index with sodium nitroprusside. With a similar increment in CI, the RAP was significantly decreased from baseline (21 +/- 4 torr) with sodium nitroprusside (15 +/- 3, p less than 0.001) but was unchanged with dopamine. Pulmonary arteriolar resistance index decreased significantly from baseline (375 +/- 230 dynes sec cm-5/m2) with sodium nitroprusside (169 +/- 132, p less than 0.001), and, interestingly, with dopamine as well (273 +/- 165, p less than 0.05). Both dopamine and sodium nitroprusside in these dosages have favorable effects on CI and pulmonary arteriolar resistance index in patients after right atrium-pulmonary artery bypass. Whenever feasible, sodium nitroprusside is preferred for increasing CI after such a bypass procedure, since lower RAP decreases the severity of fluid retention, ascites, and chest tube drainage.

Comparative hemodynamic effects of dopamine and dobutamine in patients with acute cardiogenic circulatory collapse

The hemodynamic effects of dopamine (DPM) and dobutamine (DBM) were compared in 13 patients with acute cardiogenic circulatory collapse. All patients presented with acute pump failure and inadequate systemic perfusion, and most were hypotensive. Nine patients had an acute myocardial infarction (AMI); the other four patients had an acute decompensation of a previously stable ischemic cardiomyopathy, and presented with a low-output syndrome in the absence of documented AMI. Patients were studied with a randomized single crossover design using each patient as his own control. Both drugs were given at doses of 2.5, 5, and 10 micrograms/kg/min for periods of 10 minutes at each dose while hemodynamics were monitored. No other vasoactive drugs were used during the study. Because of advanced age or severe peripheral vascular disease, no patient was considered suitable for intra-aortic balloon counterpulsation. There were no significant differences between the two drugs with regard to heart rate, mean-arterial pressure, systemic vascular resistance, stroke work index, or mean right atrial pressure. DBM improved stroke index and cardiac index significantly (p less than 0.05) more than DPM at doses of 5 micrograms/kg/min. DPM increased left ventricular filling pressure (LVFP) more than DMB at 5 micrograms/kg/min (p less than 0.001) and at 10 micrograms/kg/min (p less than 0.05). Although both DPM and DBM are useful in acute cardiogenic circulatory collapse, there appear to be important differences in their effect on LVFP and in the mechanisms whereby they increase blood pressure.

Dopamine gangrene. Association with disseminated intravascular coagulation

Multiple extremity gangrene developed in five patients as a complication of dopamine therapy. The clinical conditions were (1) penetrating chest trauma requiring pneumonectomy with postoperative sepsis, (2) cardiac arrest with aspiration pneumonia, (3) lymphoma with sepsis, (4) Klebsiella pneumonia, and (5) myocardial infarction. The development of acrocyanosis leading to gangrene occurred at dopamine dosages of 5.1 to 10.2 micrograms/kg/min. The alpha-adrenergic vasoconstriction effects of dopamine would not be expected from the doses employed in these patients. Thus, other factors beside pure alpha vasoconstriction are responsible for tissue necrosis after the use of dopamine. We believe that the embolic complications of disseminated intravascular coagulation and hypovolemia are serious risk factors in the development of dopamine gangrene. Peripheral vasoconstriction from dopamine, even at low doses, may set the stage for thrombotic complications of disseminated intravascular coagulation and lead to tissue damage. In laboratory models of disseminated intravascular coagulation, an alpha-adrenergic drug is required to produce peripheral ischemic tissue damage. Treatment of tissue ischemia related to dopamine depends on early recognition of acrocyanosis. Phentolamine, an alpha blocker, has been recommended for treating dopamine ischemia, either through local instillation into ischemic tissues or intravenous infusion. We recommend a high index of suspicion for, and early treatment of, underlying consumptive coagulopathy in all patients requiring dopamine.

Low cardiac output states after open heart surgery. Comparative hemodynamic effects of dobutamine, dopamine, and norepinephrine plus phentolamine

The hemodynamic effects of dobutamine, dopamine, and a combination of norepinephrine-phentolamine were compared in nine patients with low cardiac output state after open heart surgery. Using a Latin square design for drug sequence, each patient was given each drug at three levels by continuous intravenous infusion. For dobutamine and dopamine the doses were 2.5, 5.0 and 10.0 microgram/kg/min; for norepinephrine, 0.02, 0.05 and 0.10 microgram/kg/min with phentolamine in the ratio of 1 (norepinephrine) to 2.5 (phentolamine). Dobutamine and dopamine both produced an increase in heart rate, mean arterial pressure, cardiac index, and stroke volume index. Both drugs reduced total pulmonary and systemic vascular resistance in the dose range of 5.0 to 10.0 microgram/kg/min. When the maximum tolerated doses were compared, the drugs equally increased cardiac index and stroke volume index, but dopamine did so at a smaller dose than dobutamine. At equivalent doses, dobutamine tended to produce less tachycardia and vasoconstriction than dopamine. The norepinephrine-phentolamine combination resulted in increases in both systemic arterial pressure and vascular resistance with no significant increase in cardiac index. Its unique feature was its predictable vasopressor response with absence of chronotropic effects and ventricular irritability.

Hemodynamic and cardiometabolic effects of prenalterol in patients with acute myocardial infarction and shock

Five patients with acute myocardial infarction and shock were treated with a new, highly selective beta-1-adrenoreceptor agonist, prenalterol. After 1 and 2 mg of the drug, all patients had markedly increased blood pressure and cardiac output, but no changes in heart rate or systemic vascular resistance. Left- and right-sided filling pressures decreased in three of the patients. In two of the patients, however, the increase in contractility and afterload was followed by a marked increase in left- and right-sided filling pressures, and myocardial lactate uptake changes to lactate production. After addition of sodium nitroprusside, blood pressure and filling pressures returned towards normal, and myocardial lactate uptake was restored. As anticipated from the hemodyanamic findings, myocardial oxygen consumption increased after prenalterol. It is suggested that the potent inotropic agent prenalterol may be used with great caution in cardiogenic shock.

Comparison of haemodynamic responses to dopamine and salbutamol in severe cardiogenic shock complicating acute myocardial infarction

Twelve patients with severe persistent cardiogenic shock complicating acute myocardial infarction underwent single crossover treatment with intravenous dopamine and salbutamol to determine the more beneficial therapy. Salbutamol (10 to 40 microgram/min) reduced systemic vascular resistance and progressively increased both cardiac index and stroke index. Heart rate increased from 95 to 104 beats/min. Changes in mean arterial pressure and pulmonary artery end-diastolic pressure were small and insignificant. Dopamine infusion at rates of 200 and 400 micrograms/min also increased cardiac index and stroke index. Systemic vascular resistance fell slightly but mean arterial pressure rose from 57 to 65 mm Hg. Heart rate increased from 95 to 105 beats/min. Changes in pulmonary artery end-diastolic pressure were again small and insignificant. Dopamine infusion at 800 micrograms/min caused an appreciable increase in systemic vascular resistance; a further increment in mean arterial pressure was observed, though cardiac index fell slightly. Heart rate and pulmonary artery end-diastolic pressure rose steeply. Salbutamol, a vasodilator, increased cardiac output in patients with cardiogenic shock complicating acute myocardial infarction but did not influence blood pressure. If correction of hypotension is essential dopamine in low doses may be the preferred agent. Doses of 800 microgram/min, which is within the therapeutic range, worsen other manifestations of left ventricular dysfunction.

Sympathomimetic amines

The autonomic nervous system may play an important role in tissue autoregulation as the neurohumoral transmission process has been shown to constitute the final common pathway by which the effects of many physiological and pharmacological substances are mediated. The effects of the administration of a sympathomimetic amine cannot be accurately predicted in a subject. Choice of which sympathomimetic amine to use should be determined on the basis of data obtained in relevant clinical circumstances, but the dose should always be titrated against the effect in each individual. It is interesting that adrenaline, "the original autonomic drug" with its "venerable history", is still a first line drug in many of the situations for which it was being prescribed in 1907. It is the drug of first choice in anaphylactic reactions and for severe allergic bronchospasm, and is widely used as a vasoconstrictor in surgery and with local anaesthetic agents. Adrenaline in "physiological" doses is a satisfactory and cheap alternative to other available drugs for use in septic shock and in emergence from cardiopulmonary bypass.

The hemodynamic effects of dopamine in infants after corrective cardiac surgery

The hemodynamic effects of dopamine were measured during the immediate postoperative period in five infants with low cardiac output following repair of congenital cardiac defects. Dopamine was administered at doses of 5, 10, 15, 20 and 25 micrograms/kg/minute. Heart rate, systemic arterial pressure, and cardiac index increased significantly at a dose of 15 micrograms/kg/minute or greater. There were no significant changes in right atrial pressure, left atrial pressure, pulmonary artery pressure, pulmonary vascular resistance, systemic vascular resistance, or stroke volume. These data support the hypothesis that inants respond to dopamine in a fashion qualitatively and quantitatively different from that in adults.

Comparative haemodynamic effects of dopamine and dobutamine in septic shock

Septic shock associated with depressed myocardial function generally requires the use of catecholamine. Currently dopamine is often selected. Dobutamine is a newly developed catecholamine which has been shown to be of value in severe cardiomyopathic disease. The aim of this work was to determine the most appropriate drug by comparing haemodynamic responses to dopamine and dobutamine in 19 studies carried out in 11 patients with septic shock and heart failure. Cardiac index increased siliarly with dopamine and dobutamine (33%), as did stroke volume (respectively 26.4 and 25%). Arterial pressure increased by 17% with dopamine whereas it did not significantly change with dobutamine due to reduction in vascular resistance of 19%. Dobutamine decreased filling pressure, either right (14%) of left (28%) whilst they slightly but unsignificantly increased with dopamine. Pulmonary shunting increased more with dopamine (47%) than with dobutamine (16%), but PaO2 remained constant with both. Since septic shock is characterized by lowered arterial pressure and vasodilatation it is concluded that effects of dopamine on capacitance and resistance vessels make this drug more suitable. In addition it selectively increases renal blood flow. Nevertheless dobutamine could be appropriate, in case of very high filling pressures, severe peripheral vasoconstriction, marked pulmonary shunting and in some cases where dopamine becomes ineffective.

Haemodynamic effects of dobutamine with special reference to myocardial blood flow. A comparison with dopamine and isoprenaline

The haemodynamic effects of dobutamine (2.5 to 10 micrograms/min per kg) were determined in 5 patients without cardiac failure who were undergoing cardiac catheterisation for suspected coronary disease. Myocardial blood flow was determined by the coronary sinus thermodilution technique. Data were compared with those from two groups of 5 patients who received dopamine (4-8 micrograms/min per kg) and isoprenaline (0.005-0.025 micrograms/min per kg). Each drug was given in a lower and a higher dose, and all increased mean cardiac index (dobutamine, 18% and 39%; dopamine, 11% and 23%; isoprenaline, 15% and 44%). These increases were associated with significant increases in mean myocardial oxygen consumption (dobutamine, 38% and 61%; dopamine, 25% and 62%; isoprenaline, 20% and 45%). Mean myocardial blood flow was increased by each drug but mean myocardial oxygen extraction was decreased by isoprenaline, was increased by dopamine, and was unchanged by dobutamine. Each inotropic agent has a similar effect on myocardial oxygen consumption, but isoprenaline has a direct coronary vasodilator action while dopamine has a coronary vasoconstrictor action. Dobutamine has no direct effect upon coronary vascular tone.

Beneficial effects of prolonged low dose dopamine in hospitalized patients with severe refractory heart failure

In 10 hospitalized patients with severe congestive heart failure refractory to standard medical therapy for three days, low dose intravenous dopamine (2-4 micrograms/kg/min) was infused for 48 h. Heart rate and systolic blood pressure were unchanged throughout the study. Mean pulmonary artery wedge pressure decreased significantly during the dopamine infusion from 27 +/- 6 (SD) to 18 +/- 6 mmHg (p less than 0.01) and cardiac output increased from 3.2 +/- 1.1 to 4.6 +/- 0.8 l/min (p less than 0.001). A diuresis was initiated in all patients and there was a significant weight loss during the study which averaged 5 lbs (p less than 0.01). All patients improved symptomatically from class IV (NYHA) to class III and were more responsive to conventional therapy after the study. No adverse reactions were noted in this dose range. We conclude that low dose intravenous dopamine is efficacious in improving hemodynamics and initiating a diuresis in patients with severe refractory congestive heart failure.

Vasodilator therapy of pump failure complicating acute myocardial infarction

In patients with pump failure complicating acute infarction, vasodilating drugs, by reducing impedance to left ventricular outflow and venous return to the heart, improve cardiac performance without affecting myocardial contractility. Sodium nitroprusside currently is the vasodilator of choice in most patients with both elevated left ventricular filling pressures and reduced cardiac output. Patients with accompanying mechanical defects, such as acute mitral regurgitation or ventricular septal rupture, are particularly amenable to vasodilator therapy. Some patients may require combined therapy, with inotropic catecholamines or mechanical assistance devices together with vasodilators, in order to avoid undesirable hypotension. Side effects and toxicity are rare when patients are carefully selected and monitored. It is uncertain whether vasodilators reduce ischemia or salvage jeopardized myocardium, but they appear to improve the initial prognosis of some patients with severe pump failure. The long-term prognosis of these patients remains poor, however, and therefore a more aggressive approach to their chronic management seems warranted.

Treatment of aneurysmal hemiplegia with dopamine and mannitol

Three patients with severe postoperative hemiplegia and one with hemiplegia following a subarachnoid hemorrhage are presented. None had hematomas. All were treated with dopamine-induced hypertension, mannitol, and large quantities of intravascular fluids. All showed a remarkable degree of clinical improvement, presumably secondary to an increase in cerebral blood flow.

Hospital treatment of congestive heart failure. Management according to hemodynamic profile

Selection of therapy for subjects with acute congestive dardiac failure usually involves a choice among a diuretic, a vasodilator and an inotropic agent. Three principal questions are involved in the decision: (1) Is cardiac out normal or depressed? (2) Is blood pressure normal or depressed? (3) is regional myocardial ischemia present? Diuretics are safe and easy to administer, but they do not increase cardiac output or relieve hypoperfusion. Inotropic agents increase cardiac output but differ widely in their effects on blood pressure: selection of specific agents is influenced by their blood pressure effect. All inotropic agents, however, potentially aggravate regional myocardial ischemia. In ischemic heart failure, therefore, vasodilators which also increase cardiac output, may be chosen. Vasodilator administration is in turn limited by the decrease in arterial pressure which accompanies increasing infusion rate. When these three questions are considered in combination, an effective therapeutic regimen can be identified. Thus, congestion without hypoperfusion requires a diuretic if blood pressure is normal; and a vasodilator when blood pressure is increased. In the presence of congestion with hypoperfusion, a vasodilator is employed if blood pressure is normal; and a positive inotropic drug when blood pressure is depressed.

The MAST suit in the treatment of cardiogenic shock

Based on initial success using the medical antishock trouser (MAST) suit in treating 150 patients in traumatic, hypovolemic shock in the city of Bellingham and Whatcom County, Washington, at St. Luke's Hospital, the indications for its use have been expanded to include certain types of cardiogenic shock. The rationale was based on the frequent inability to differentiate hypo-, hyper-, and normovolemia in patients in cardiogenic shock and the need for a safe, reversible fluid challenge to differentiate these conditions. Changes in the condition of 14 patients in cardiogenic shock after application of the MAST suit were evaluated. Six patients responded with improved cardiac output and blood pressure. Four had no significant change in their condition and four became worse. In all patients whose condition was unchanged or worsened, the fluid challenge was reversed by deflating the suit. Based on these preliminary findings, it would seem that extended indications exist for using the MAST suit.

The use of dopamine in children

Dopamine was used as the primary catecholamine to treat circulatory shock, manifested by either systemic arterial hypotension or oliguria or both, in 24 children two days to 18 years (mean = 39 months) of age. The dose of dopamine ranged from 0.3 to 25 (mean = 9.3) microgram/kg/minute. The primary problem in four of the 24 patients was infection; two of these patients survived. The other 20 patients had congenital heart disease; 18 developed shock following surgery. Even of these 20 patients survived. With dopamine infusion the average systolic blood pressure increased from 69 +/- 4 (mean +/- SEM) to 81 +/- 4 mm Hg (P less than 0.001) and the mean urine output increased from 0.8 +/- 0.2 to 2.7 +/- 0.8 ml/kg/hour (P less than 0.05). Dopamine produced no adverse consequences. Thirteen patients responded favorably to the drug, with a significant increase in systemic arterial blood pressure and urine production. Four patients did not respond to dopamine and seven had an equivocal response. None of the four patients in whom dopamine was ineffective survived. Although only nine of the 20 patients who responded favorably or equivocally survived, conventional therapy had failed to alter the unfavoarble course in any of the patients.

Effect of dopamine on hemodynamics and myocardial metabolism in shock following acute myocardial infarction in man

Eight patients in shock associated with acute myocardial infarctions were treated with dopamine. We titrated the dopamine dose to increase mean arterial pressure to 65-70 mm Hg and urine output to greater than 40 ml/hr. Increase of heart rate to 120-125 beats/min and occurrence of potentially dangerous arrhythmias were limiting end-points. Dopamine administration averaged 17.2 microgram/kg/min. Heart rate increased from 95 to 118 beats/min (P less than 0.001), and mean arterial pressure rose from 60 to 65 mm Hg (P less than 0.05). Dopamine increased myocardial contractility as indicated by increase in cardiac index and systolic ejection rate, with only moderate decrease in systemic vascular resistance. Pulmonary wedge pressure and right atrial pressure decreased from 23 to 18 mm Hg (P less than 0.05) and from 10 to 8 mm Hg (P less than 0.001) respectively. Improvement in hemodynamic status by dopamine was associated with deterioration of myocardial metabolism. Myocardial oxygen extraction ratios and arterial-coronary sinus oxygen differences increased from 73 to 76% (P less than 0.05) and from 13.02 to 14.19 ml/100 ml (P less than 0.02) respectively. Myocardial lactate production increased from -8 to -15% (P = 0.05). We conclude that dopamine improved cardiac performance at the expense of myocardial oxygenation and that dopamine is potentially harmful to acutely ischemic myocardium.

Haemodynamic effects of dopamine, epinephrine and orciprenaline (Alupent) in patients early after cardiac surgery

The haemodynamic effects of Dopamine (100, 250 and 500 mcg/min), Epinephrine (4 and 8 mcg/min), Orciprenaline (4 and 8 mcg/min) and two combinations of Dopamine 250 mcg/min with Epinephrine and Orciprenaline 4 mcg/min respectively at constant infusion rates were studied in 21 patients after cardiac surgery. Special attention was payed to four types of catecholamine infusions during which the highest cardiac index (CI), 161-168% of control, was seen: Dopamine 500 mcg/min (D 500), Epinephrine 8 mcg/min (E 8), Dopamine 250 mcg/min combined with Epinephrine 4 mcg/min (D 250 + E4) and Dopamine 250 mcg/min combined with Orciprenaline 4 mcg/min (D 250 + Or 4). At the same time mean arterial pressure (MAP) was highest with D 500 (137%) and lowest during both combined infusions (120 and 125%). Total peripheral resistance (TPR) was lowest during the combined infusions (80 and 81% of control) and highest during D 500 (89%). The relative increase of stroke index (SVI) and heart rate (HR) in favor of SVI, given as a quotient SVI/HR, was highest with D 250 + E4(3.7), followed by E 8 (1.9), D 500 (1.6) and D 250 + Or 4 (1.3). It was concluded that a combined infusion of Dopamine and Epinephrine, both in low doses, is preferable to a high dose of Dopamine, or Epinephrine alone, producing the same increase of cardiac output with less afterload and less chronotropic effect than high doses of either drug alone.