ABSTRACT
Blood gas determination provides physicians with detailed information regarding cardiopulmonary and metabolic homeostasis in the emergency patient. When integrated with the history and physical examination, the rapidly available arterial blood gas (ABG) analysis is useful in the resuscitation of the acutely ill or injured patient. This article discusses the physiology, analysis, and interpretation of ABG.
Subject(s)
Blood Gas Analysis/methods , Carbon Dioxide/blood , Oxygen/blood , Acid-Base Equilibrium , Acidosis/blood , Acidosis/etiology , Acidosis/metabolism , Adult , Alkalosis/blood , Alkalosis/etiology , Alkalosis/metabolism , Bicarbonates/blood , Bicarbonates/metabolism , Carbon Dioxide/metabolism , Emergencies , Female , Homeostasis , Humans , Hydrogen-Ion Concentration , Hypoxia/metabolism , Male , Oxygen/metabolism , Oxygen ConsumptionABSTRACT
The effect of antishock trouser inflation on plasma renin activity during hypovolemic shock was studied in dogs. Following anesthesia, six dogs were bled to a systolic blood pressure of 60 mm Hg. Antishock trousers were inflated to 40 to 100 mm Hg for 20 minutes each. Plasma renin activity was measured before phlebotomy, after phlebotomy, and after each 20-minute period of antishock trouser inflation. Three dogs without antishock trousers served as controls. Experimental animals had a significant rise in blood pressure when the antishock trousers were inflated to 100 mm Hg. Plasma renin activity showed a marked increase following phlebotomy (experimental, 1.55 ng/mL/h to 13.63 ng/mL/h; control, 2.71 ng/mL/h to 19.7 ng/mL/h). Both groups had a continued small, statistically insignificant rise in plasma renin levels throughout the remainder of the experiment. Plasma renin level changes did not explain the observed rise in blood pressure following antishock trouser inflation. Plasma renin levels remained elevated in spite of improvement of blood pressure after application of antishock trousers.
Subject(s)
Gravity Suits , Hemodynamics , Renin/blood , Shock/therapy , Animals , Blood Pressure , Dogs , Renal Circulation , Shock/blood , Shock/physiopathology , VasoconstrictionABSTRACT
The general concepts of defibrillation are reviewed. Research continues in the area of implanted defibrillators, new circuiting, and more effective current transfer.
Subject(s)
Electric Countershock , Resuscitation/methods , Ventricular Fibrillation/therapy , Cardiac Catheterization , Electric Countershock/adverse effects , Electric Countershock/instrumentation , Electric Countershock/methods , Electricity , Heart/physiopathology , Humans , Ventricular Fibrillation/physiopathologyABSTRACT
A technique of direct mechanical ventricular assistance (DMVA) has been available since 1966. Ventricular assistance is provided by a glass cup lined with a Silastic diaphragm. It is held on the cardiac ventricles by suction. Alternating positive and negative pressure in the space between the cup and the diaphragm provides a pumping mechanism for blood flow. DMVA was compared to closed chest massage (CCM) and open chest massage (OCM) during ventricular fibrillation in six dogs. Each technique was applied for 10 minutes. Three dogs had CCM followed by OCM and then DMVA. Three dogs had only OCM and DMVA. Blood pressure and cardiac output were measured. All variables were calculated as a percentage of pre-ventricular-fibrillation values. Mean blood pressure was 19.7% with CCM, 39.8% with OCM, and 55.1% with DMVA. Systolic blood pressure was 25.8% with CCM, 51.9% with OCM, and 64.0% with DMVA. Diastolic blood pressure was 17.3% with CCM, 37.3% with OCM, and 48.9% with DMVA. Cardiac output was 13.8% with CCM, 37.1% with OCM, and 58.0% with DMVA. For each variable, OCM produced statistically higher values than did CCM. DMVA produced statistically higher values than did OCM for all variables. These preliminary results suggest that DMVA may be superior to currently available methods of cardiac massage during ventricular fibrillation.
