Monitoring tissue oxygenation during resuscitation of major burns

Background: Because subcutaneous and splanchnic oxygenation indices are sen sitive indicators of evolving hemorrhagic shock and adequacy of resuscitati on, we postulated that these indices might have an equivalent role in the m onitoring of severely burned patients, This observational study was underta ken to examine changes in tissue oxygenation indices during burn resuscitat ion, Methods: seven patients with major burns (54 +/- 21% total body surface are a) were studied during the first 36 hours of fluid resuscitation. Silastic tubing was placed in the subcutaneous tissue just beneath both normal skin and deep partial thickness burn. Fiberoptic sensors inserted into the tubin g measured subcutaneous oxygen and carbon dioxide tensions in the burnt ski n (Po-2scb and Pco(2scb)) and normal skin (Po-2scn and Pco(2scn)) continuou sly, Gastric intramucosal pH (pHi)and the mucosal CO2 (Pco(2m)) gap were ca lculated using gastric tonometers, Mean arterial pressure, arterial pH, lac tate, and pHi measurements were obtained for 36 hours. Results: There were no significant differences in mean arterial pressure, a rterial pH, or lactate concentrations throughout the study period, whereas indices of tissue oxygenation showed deterioration: pHi decreased from 7.2 +/- 0.1 to 6.7 +/- 0.3 (p = 0.06), the Pco(2m) gap increased from 12 +/- 17 to 108 +/- 123 mm Hg (p < 0,01), Po-2scn decreased from 112 <plus/minus> 1 8 to 50 +/- 11 mm Hg (p < 0,01), Po-2scb decreased from 62 <plus/minus> 23 to 29 +/- 16 mm Hg (p < 0,01), Pco(2scn) increased from 42 <plus/minus> 4 t o 46 +/- 10 mm Hg (p = 0.2), and Pc-2scb increased from 42 +/- 10 to 52 +/- 5 mm Hg (p = 0,05). Conclusion: Despite adequate global indices of tissue perfusion after 36 ho urs of resuscitation, tissue monitoring indicated significant deterioration in the splanchnic circulation and in the normal and burnt skin.