Hyperbaric oxygen therapy induces kidney protection in an ischemia/reperfusion model in rats.

Ischemia/reperfusion (I/R) injury remains a major cause of graft dysfunction, which impacts short- and long-term follow-up. Hyperbaric oxygen therapy (HBO), through plasma oxygen transport, has been currently used as an alternative treatment for ischemic tissues. The aim of this study was to analyze the effects of HBO on kidney I/R injury model in rats, in reducing the harmful effect of I/R. The renal I/R model was obtained by occluding bilateral renal pedicles with nontraumatic vascular clamps for 45 minutes, followed by 48 hours of reperfusion. HBO therapy was delivered an hypebaric chamber (2.5 atmospheres absolute). Animals underwent two sessions of 60 minutes each at 6 hours and 20 hours after initiation of reperfusion. Male Wistar rats (n = 38) were randomized into four groups: sham, sham operated rats; Sham+HBO, sham operated rats exposed to HBO; I/R, animals submitted to I/R; and I/R+HBO, I/R rats exposed to HBO. Blood, urine, and kidney tissue were collected for biochemical, histologic, and immunohistochemical analyses. The histopathological evaluation of the ischemic injury used a grading scale of 0 to 4. HBO attenuated renal dysfunction after ischemia characterized by a significant decrease in blood urea nitrogen (BUN), serum creatinine, and proteinuria in the I/R+HBO group compared with I/R alone. In parallel, tubular function was improved resulting in significantly lower fractional excretions of sodium and potassium. Kidney sections from the I/R plus HBO group showed significantly lower acute kidney injury scores compared with the I/R group. HBO treatment significantly diminished proliferative activity in I/R (P < .05). There was no significant difference in macrophage infiltration or hemoxygenase-1 expression. In conclusion, HBO attenuated renal dysfunction in a kidney I/R injury model with a decrease in BUN, serum creatinine, proteinuria, and fractional excretion of sodium and potassium, associated with reduced histological damage.

Lymphscintigraphic evaluation of manual lymphatic drainage for lower extremity lymphedema.

To evaluate the effect of manual lymphatic drainage on technetium-99m-labeled dextran (99mTcDx) transport, 16 patients with lymphedema of lower extremities underwent two lymphscintigraphy exams by injecting 99mTcDx intradermally into the first interdigital space of the affected extremity. The first was a control examination at rest followed by an examination which included a manual lymphatic drainage session after the injection of the 99mTcDx. Images were obtained 45 minutes and three hours after the injection of the radioisotope. Extremity volumes were also measured before and after the drainage session. The findings from the examinations were assessed in a quantitative, semiquantitative and qualitative manner and compared without and with drainage. The analyses of the extremities' circumference before and after the drainage by paired t-test revealed a significant decrease. The analyses of the quantitative, semi-quantitative and qualitative evaluations evidenced no significant difference, without or with drainage, within the 45-minute and three-hour periods. Thus, manual lymphatic drainage caused an effective reduction in the circumference of the extremities but did not have a significant effect in the transport of 99mTcDx.

Pulmonary hypertension and systemic vasoconstriction may offset the benefits of acellular hemoglobin blood substitutes.

OBJECTIVE: We tested the hypothesis that the pharmacologic properties of a small volume of alpha alpha-cross-linked hemoglobin (alpha alpha Hb) could effectively resuscitate pigs subjected to hemorrhage. METHODS: Fourteen pigs hemorrhaged to a mean arterial pressure (MAP) of 40 mm Hg for 60 minutes were treated with a 4-mL/kg 2-minute infusion of 10 g/dL alpha alpha Hb or 7 g/dL human serum albumin, an oncotically matched control solution. RESULTS: The removal of blood (17 +/- 1.5 mL/kg) caused the typical physiologic responses to hemorrhagic hypovolemia. Infusion of alpha alpha Hb restored mean arterial pressure and coronary perfusion pressure, but cardiac output and mixed venous O2 saturation did not improve significantly. Pulmonary arterial pressure and pulmonary vascular resistance increased markedly and were higher than baseline levels after alpha alpha Hb. Infusion of human serum albumin produced only minor hemodynamic changes. Brain blood flow did improve to baseline values after alpha alpha Hb, but was the only tissue to do so. In the human serum albumin group, superior mesenteric artery blood flow recovered to baseline values, whereas brain blood flow did not. Blood flows to other tissues were similar in both groups. CONCLUSION: Small-volume infusion of alpha alpha Hb restored mean arterial pressure and brain blood flow, but pulmonary hypertension and low peripheral perfusion may offset benefits for trauma patients.