Abstract 6: Comparison of Intra-aortic Aqueous Oxygen Versus Intravenous Norepinephrine in a Swine Model of Hemodynamic Shock Associated with Acute Isovolemic Critical Anemia
Background: During isovolemic exchange transfusion with Lactated Ringer’s Solution (LR), hemodynamic shock (HS) occurs rapidly at a [Hb] < 3 g %. Recently, we demonstrated that IA-AO improves mean arterial pressure (MAP) and end-tidal CO2 (Et-CO2) in a swine model of HS. However, whether i.v. norepinephrine (NE) is similarly effective in this model is unknown.
Methods: Juvenile domestic swine (30 ± 5 kg; n = 10) were anesthetized with isoflurane and ventilated with 35 % FiO2. After a 2 hour baseline, blood exchange was performed with 37oC LR over 1 hour in a ratio (1: 1.2) to maintain CVP 2-8 mmHg while reducing [Hb] < 3 g %, resulting in HS, defined as < 50% of baseline MAP and Et-CO2 < 25 mmHg. In the AO group (n = 5), IA-AO was then performed with a 5F catheter at 30 mL O2/min for 1-2 min, at 5 - 8 min intervals. In the NE group (n = 5), NE was infused i.v. at 48 mcg/min. For asystole, chest compression was performed, and i.v. epinephrine 1mg given only for the NE group. Transesophageal echo (TEE) was monitored continuously and velocity time integral (VTI) determined intermittently.
Results: In the first 5 min. of HS, MAP (% baseline) significantly improved in both groups (p < 0.05). MAP was greater for the AO group than the NE group during 6-15 min (52 ± 8 vs 34 ± 13 mm Hg) and 16-30 min (98 ± 48 vs 29 ± 1 mm Hg) of HS (p < 0.05). Mean Et-CO2 in the NE group (20 ± 2 mm Hg) was significantly lower than the IA-AO group (33±3 mm Hg) throughout HS (p < 0.01). Survival at 25 min of HS was significantly longer for AO (100 %) than for NE (40 %) (P < 0.05). VTI by echo was greater for AO (12 ± 4 mL) vs. NE (4 ± 2 mL) during HS (p < 0.05).
Conclusion: IA-AO infusion is more effective than i.v. NE in treatment of hemodynamic shock in this model.
Author Disclosures: L. Muthukumar: None. N. Katukuri: None. S.K. Jafri: None. Y. Khouri: None. I. Shaik: None. R. Hammonds: None. P. Prcevski: None. S. Jahania: None. J.R. Spears: None.
- © 2014 by American Heart Association, Inc.