Abstract 142: Augmentation of Negative Intrathoracic Pressure Improves Hemodynamics Without Popping the Clot: A Randomized Study Comparing an Impedance Threshold Device vs Saline to Treat Severe Hemorrhage Through Permissive Hypotension in a Spontaneously Breathing Porcine Model
Objective: An evolving concept in the field of trauma care is the prehospital management of shock associated with uncontrolled hemorrhage. Traditional prehospital care includes early and aggressive intervention focusing on fluid resuscitation. In recent years, however, early aggressive fluid replacement has become the subject of controversy as studies have demonstrated increased blood loss and mortality associated with this therapy. In contrast to aggressive fluid resuscitation, the technique of permissive hypotension has demonstrated increased long-term survival in both animal and human studies. Permissive hypotension minimizes hemodilution, intra-operative blood loss, and prehospital blood loss by preventing popping of the clot. We hypothesized that that augmentation of negative intrathoracic pressure (nITP) by spontaneously breathing through an impedance threshold device (ITD) would improve hemodynamics and provide permissive hypotension with less hemodilution and risk of popping the clot in a porcine model of severe hemorrhagic shock.
Methods: Twenty-seven spontaneously breathing female pigs (30.6 ± 0.5 kg), anesthetized with propofol, were subjected to a 55% bleed and randomized equally in a prospective, blinded manner to either nITP, no treatment, or iv bolus of 1 L of saline (NaCl) and evaluated acutely for 30 minutes.
Results: Results are reported as mean ± SEM and shown in Table 1.
Conclusion: In this porcine model of hemorrhagic shock, the nITP treatment significantly improved systolic blood pressure (SBP) and pulse pressure (PP) for 30 minutes in an equivalent manner to the 1L NaCl treatment without exceeding SBPs associated with popping the clot and hemodilution.
- © 2011 by American Heart Association, Inc.