Inotropic agents in the treatment of cardiogenic shock

Utility of glucagon in the emergency department

Glucagon is a pancreatic polypeptide hormone that has diverse utility as both a therapeutic and diagnostic agent. Many of its pharmacologic actions are pertinent to the practice of emergency medicine. The author reviews the literature supporting each potential use of the drug and the purported physiologic mechanisms by which glucagon exerts these actions. The indications and proper dosages for glucagon in the acute care setting are summarized.

Septic shock. When patients fail to respond to conventional therapy

Patients in septic shock require rapid evaluation and prompt initiation of therapy with appropriate antibiotics and fluids. When fluids do not restore perfusion, dopamine (Dopastat, Inotropin) therapy is begun. Some patients who fail to respond to these measures will respond to a combination of low-dose dopamine and regulation of blood pressure with norepinephrine (Levophed).

Anaesthetic management of emergency caesarean section followed by pulmonary embolectomy

This report discusses the anaesthetic management of a patient undergoing emergency Caesarean section followed by an open pulmonary embolectomy with cardiopulmonary bypass. This case was complicated by the major physiological alterations associated with pregnancy and delivery, massive blood loss, cardiac dysrhythmias, hypotension, and cardiac arrest. Both patients, mother and child, made a full recovery.

Quantitative two-dimensional echocardiography in massive pulmonary embolism: emphasis on ventricular interdependence and leftward septal displacement

In 14 patients requiring aggressive therapy for circulatory failure resulting from massive pulmonary embolism, hemodynamic and two-dimensional echocardiographic data were obtained at bedside (acute phase) and again after circulatory improvement (intermediate phase) and during recovery. The acute stage was characterized by a low cardiac output state despite inotropic support (cardiac index 1.9 +/- 0.6 liters/min per m2) associated with increased right atrial pressure (12.4 +/- 4.2 mm Hg), increased right ventricular end-systolic and end-diastolic area (12.4 +/- 3.4 and 15.4 +/- 4.1 cm2/m2, respectively) and reduced right ventricular fractional area contraction (20.1 +/- 8.6%). Two-dimensional echocardiography also revealed interventricular septal flattening at both end-systole and end-diastole and markedly decreased left ventricular end-diastolic dimensions. Left ventricular fractional area contraction remained normal. Hemodynamic improvement occurred during the intermediate phase as shown by restoration of cardiac index (3.3 +/- 0.6 liters/min per m2), decrease in right atrial pressure (8.3 +/- 4.8 mm Hg), reduction in right ventricular end-systolic area (9.0 +/- 3.6 cm2/m2 at the intermediate stage and 6.1 +/- 1.8 cm2/m2 at recovery) and end-diastolic area (10.5 +/- 3.6 cm2/m2 at the intermediate stage and 8.9 +/- 2.9 cm2/m2 at recovery) and improvement in right ventricular fractional area contraction (31.5 +/- 16.4%). The interventricular septum progressively returned to a more normal configuration at both end-systole and end-diastole, and left ventricular diastolic dimension steadily increased. It is concluded that circulatory failure secondary to massive pulmonary embolism was mediated through a profound decrease in left ventricular preload, resulting from both pulmonary outflow obstruction and reduced left ventricular diastolic compliance.(ABSTRACT TRUNCATED AT 250 WORDS)

Short- and long-term dobutamine treatment in chronic ischemic heart failure

This study was undertaken in order to characterize the short-term (1 hour) and long-term (72 hours) effect of dobutamine on hemodynamic and regional ejection fraction parameters measured by radionuclear angiography in patients with chronic congestive heart failure due to coronary artery disease. Baseline hemodynamic and radionuclear parameters were measured and then intravenous dobutamine (8.5 mu/kg/min) was administered. The above parameters were determined again after 1 hour and 72 hours of continuous dobutamine administration. Sixty minutes (short-term) after dobutamine administration heart rate and cardiac index increased significantly (p less than 0.001 for both) and peripheral resistance decreased concomitantly (p less than 0.005). Global left ventricular ejection fraction (LVEF) as measured by multigated equilibrium nuclear angiography (MUGA) increased from 21.8 +/- 10.6% to 25 +/- 13.5 (p less than 0.02). Count-based mean regional ejection fraction in the septal, inferoapical, posterolateral (45 degrees left anterior oblique view) and inferior apical and anterolateral (30 degree right anterior oblique gated first pass) regions increased also. At 72 hours (long-term) after continuous dobutamine infusion, heart rate and cardiac index were still significantly higher and peripheral resistance lower than in the control study. However, global and count-based regional ejection fraction decreased to control values in the right anterior oblique view (first-pass analysis) and the left anterior oblique view (MUGA). Global LVEF measured in the right anterior oblique view by first-pass technique was significantly higher than control in the long-term study (23 +/- 9.7 vs. 27.8 +/- 2.4; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary resuscitation. A current perspective

Cardiopulmonary resuscitation is effective if established early and coupled with specific therapeutic interventions. Most cardiopulmonary arrest is due to ventricular fibrillation and early defibrillation offers the highest probability of success. External cardiac compression alone is inadequate to provide adequate perfusion to vital organs and, therefore, cannot sustain life unless coupled with advanced therapeutic interventions. Many new techniques for increasing flow have been developed, but have not been established clinically. The American Heart Association guidelines for CPR are still valid and are the basis for our current CPR. A practical perspective is presented whereby the therapeutic interventions are pursued systematically in an expeditious and coordinated fashion so that the key interventions are made within the first 10 to 15 minutes of the arrest.