J C Puyana1, B R Soller, S Zhang, S O Heard. 1. Department of Surgery, Brigham & Women's Hospital, Boston, Massachusetts 02115, USA. jcpuyana@zeus.bwh.harvard.edu
Abstract
BACKGROUND: The rate and magnitude of pH changes in the bowel during hemorrhagic shock are greater than those in the stomach, implying that gastric intramucosal pH may not be a reliable indicator of gut perfusion. Here, we evaluate near-infrared spectroscopy (NIRS) to assess bowel pH in a swine shock model. METHODS: Laparotomy was performed to place flow probes, pH microelectrodes, and NIRS probes. Shock was maintained for 45 minutes at a blood pressure of 45 mm Hg, and resuscitation was achieved with shed blood and lactated Ringer's solution to baseline over 60 minutes. RESULTS: Hemodynamic measurements were significantly reduced during shock. Lactic acid peaked during resuscitation and remained elevated. NIRS-measured pH was correlated to electrode-measured pH (R2 = 0.903 [ischemia] and R2 = 0.889 [reperfusion]). Estimated measurement accuracy after subject-specific offset correction was 0.083 pH units during ischemia and 0.076 pH units during reperfusion. CONCLUSION: NIRS determination of small-bowel pH may be a good tool to monitor the adequacy of resuscitation.
BACKGROUND: The rate and magnitude of pH changes in the bowel during hemorrhagic shock are greater than those in the stomach, implying that gastric intramucosal pH may not be a reliable indicator of gut perfusion. Here, we evaluate near-infrared spectroscopy (NIRS) to assess bowel pH in a swine shock model. METHODS: Laparotomy was performed to place flow probes, pH microelectrodes, and NIRS probes. Shock was maintained for 45 minutes at a blood pressure of 45 mm Hg, and resuscitation was achieved with shed blood and lactated Ringer's solution to baseline over 60 minutes. RESULTS: Hemodynamic measurements were significantly reduced during shock. Lactic acid peaked during resuscitation and remained elevated. NIRS-measured pH was correlated to electrode-measured pH (R2 = 0.903 [ischemia] and R2 = 0.889 [reperfusion]). Estimated measurement accuracy after subject-specific offset correction was 0.083 pH units during ischemia and 0.076 pH units during reperfusion. CONCLUSION: NIRS determination of small-bowel pH may be a good tool to monitor the adequacy of resuscitation.
Authors: Todd W Costantini; Brian P Eliceiri; Carrie Y Peterson; William H Loomis; James G Putnam; Andrew Baird; Paul Wolf; Vishal Bansal; Raul Coimbra Journal: Mol Imaging Date: 2010-02 Impact factor: 4.488
Authors: Hyun-Joong Chung; Matthew S Sulkin; Jong-Seon Kim; Camille Goudeseune; Hsin-Yun Chao; Joseph W Song; Sang Yoon Yang; Yung-Yu Hsu; Roozbeh Ghaffari; Igor R Efimov; John A Rogers Journal: Adv Healthc Mater Date: 2013-07-19 Impact factor: 9.933