Near-infrared spectroscopy learn more (NIRS) measures aggregate oxygen saturation in a volume of tissue. We assessed the utility of continuous StO(2) measurement in a porcine model of cardiac arrest, and explored the effects of differential vasoconstriction on StO(2). We hypothesized
that (1) StO(2) trends correspond with the onset of loss of pulses, resuscitation, and return of spontaneous circulation (ROSC); (2) epinephrine has a dose-dependent effect on StO(2).
Methods: We anesthetized and instrumented 7 female swine, placing a NIRS probe on the left forelimb to recorded StO(2). After 8 min of untreated VF and 2 min of CPR, we randomized animals to 0.015 mg kg(-1) (SDE) or 0.1 mg kg-1 (HDE) epinephrine. After 3 min of CPR, animals were defibrillated. Animals with ROSC were given SDE, then HDE for subsequent hemodynamic deteriorations. Data were analyzed with descriptive statistics and generalized linear model (alpha = 0.05) to determine overall HIF cancer slope of pooled StO(2) across animals for resuscitation segments.
Results: Four animals received HDE and three SDE. All achieved ROSC. Significant coefficients (Delta StO(2) min(-1)) were noted for resuscitation segments. StO(2) decreased after loss of pulses (-29.1; 95%CI -33.4, -24.7; p < 0.01) but plateaued during CPR (-0.2; 95%CI -1.2, 0.8; p = 0.71). There was a graded decline in StO(2) between SDE
(-1.3; 95%CI – 1.5, -1.2; p < 0.01) and HDE (-3.1; 95%CI -5.8, -0.4; p = 0.03). The slowest change occurred with ROSC (0.4; 95%CI 0.3, 0.5; p < 0.01).
Conclusions: In a porcine model of OHCA, peripheral StO(2) rapidly decreased after loss of pulses, but did not improve with
CPR or epinephrine. It increased extremely slowly after ROSC. (c) 2012 Elsevier Ireland Ltd. All rights reserved.”
“The hypothesis driving this study was that photodynamic therapy (PDT) may limit abdominal aortic aneurysm growth due to matrix changes. The aortas selleck chemical of 12 rats were incubated with elastase using a newly modified experimental aneurysm model (3.5 mg/ml). Rats were allocated to an elastase-only group (n = 6) to study the elastase-induced aneurysm growth and an elastase +/- PDT group to evaluate if PDT limited aneurysm growth (n = 6). PDT was performed with the photosensitizer methylene blue, and thermoneutral laser light (660 nm) was applied (120 J/cm(2), 100 mW/cm(2)) using a diode laser. Four untreated rats served as controls. The arteries were analysed after 4 weeks based on histology, immunohistochemistry and morphometry. This modified rat elastase model led to reproducible aneurysm development with no elastase-induced mortality compared with control animals (circumference, controls: 2.9 +/- 0.2 vs. elastase: 5.5 +/- 0.9 mm; P < 0.01). PDT after elastase incubation did not inhibit inflammatory cell infiltration.