Role of fatty acids in the recovery of cardiac function during resuscitation from hemorrhagic shock.

This study tested the hypothesis that removal of fatty acids as a fuel source would improve cardiac efficiency at the expense of reduced cardiac contractile function in the isolated working heart after hemorrhage-retransfusion. Non-heparinized male Sprague-Dawley rats were anesthetized with ketamine-xylazine and were hemorrhaged to a mean arterial blood pressure of 40 mmHg for 1 h. Two-thirds volume of shed blood was reinfused together with 0.9% NaCl in a volume equal to 2.3 times the shed blood volume, followed by continuous infusion of 0.9% NaCl at 10 mL/kg per h for 3 h. Hearts were removed and perfused in closed, recirculating working mode for 60 min to measure hydraulic work and cardiac efficiency. Rates of glycolysis and glucose oxidation were assessed with [5-3H/U-14C] glucose (11 mM) in the absence or presence of 0.4 mM palmitate. Compared to baseline measurements, hemorrhage-retransfusion significantly reduced arterial blood glucose (228+/-7 versus 118+/-12 mg/dL) and non-esterified fatty acid concentrations (0.36+/-0.01 versus 0.30+/-0.02 mM), while elevating blood lactate (0.8+/-0.1 versus 2.5+/-0.4 mM). Perfusion of sham hearts with glucose-only did not alter cardiac work compared to shams perfused with glucose plus palmitate. However, shocked hearts perfused with glucose-only demonstrated a significant reduction in cardiac work compared to shocked hearts perfused with glucose plus palmitate and compared to sham hearts perfused with glucose only (P < 0.05, repeated measures ANOVA). Shocked hearts perfused with glucose plus palmitate showed no reduction in cardiac work compared to shams. Shocked hearts perfused with glucose-only had increased glucose oxidation rates compared to shams perfused with glucose plus palmitate. In sham hearts perfused with glucose-only, myocardial glycogen and triacylglycerol contents were significantly reduced compared to hearts freeze-clamped in situ. These endogenous fuels were not decreased in shocked hearts. These data indicate that hemorrhagic shock renders the heart unable to mobilize endogenous fuels, and suggest that withdrawal of fatty acid oxidation will impair myocardial energy metabolism during resuscitation.

Unique curriculum for emergency medicine residents as medical directors for rural out-of-hospital agencies.

BACKGROUND: Many rural communities have difficulty maintaining a medical director for their emergency medical services (EMS). Local physicians may be overwhelmed, be hesitant to take on additional responsibilities, and feel unskilled in providing the necessary leadership. Without a medical director, rural EMS agencies are frequently forced to shut down, thus depriving the community of local out-of-hospital care. OBJECTIVES: To meet the needs of rural EMS agencies for medical direction, to provide a unique opportunity for emergency medicine (EM) residents to acquire EMS medical direction skills, and to fulfill the obligation of EM residencies to provide both didactic and experiential training in EMS. PROGRAM DESCRIPTION: This article describes a curriculum, now being used in Colorado, for placing EM residents as EMS medical directors for rural out-of-hospital agencies that have lost their medical directors. Residents visit these rural communities 6-12 times a year, provide continuing education through interactive lectures, develop or revise EMS protocols and policies, perform quality assurance reviews, troubleshoot problems, and assist in EMS planning for the community. Residents are supervised by the Colorado state EMS medical director. CONCLUSIONS: This unique program enables local EMS agencies to continue their service while providing clear educational benefit for the EM residents. This paper demonstrates how this program has been working successfully in the state of Colorado by placing residents in four distinct rural and mountainous communities.