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Tissue Oxygen Tension (tissue + oxygen_tension)
Selected AbstractsA study of the effect of a resistive heat moisture exchanger (trachinaze) on pulmonary function and blood gas tensions in patients who have undergone a laryngectomy: A randomized control trial of 50 patients studied over a 6-month periodHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 5 2003Andrew Simpson Jones MD Abstract Background. Previous work from this department has shown that resistive tracheostomy filters increase the partial pressure of oxygen in capillary blood and also provide a significant amount of heat/moisture exchange. Until now it has not been shown whether there is any long-term beneficial effect and in particular whether raised tissue oxygenation is maintained using a practical filter device. Methods. We carried out a 6-month randomized control trial including 50 laryngectomees. Twenty-five patients were treated with the Liverpool Heat Moisture Exchange device incorporating an airway resistor (Trachinaze). Another 25 patients were treated with a placebo device. Relevant subjective and objective data were collected before and at the end of the study. The objective measurements were capillary oxygen tension (which parallels blood arterial tension), carbon dioxide tension, FEV1, FVC, and PIF. Patients were reviewed at intervals throughout the study. Data were analyzed using the Mann,Whitney U test and the paired t test to test the difference between the active device and placebo at 6 months. Results. Subjective lower airway parameters, including cough, number of chest infections, mucus production, and shortness of breath at rest, were significantly improved in the active group compared with the placebo group. The objective parameters FEV1, FVC, and PIF were not significantly different. Capillary oxygen tension, however, was highly significantly raised in the active group at 6 months. Conclusions. Trachinaze is highly superior to placebo at improving subjective pulmonary parameters, including shortness of breath. It is also superior in its ability to maintain an increased peripheral tissue oxygen tension over a 6-month period. © 2003 Wiley Periodicals, Inc. Head Neck 25: 000,000, 2003 [source] Does dopexamine influence regional vascular tone and oxygenation during intestinal hypotension?ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 10 2002S. Lehtipalo Background: Local effects of dopexamine on intestinal vascular tone and oxygenation were investigated during intestinal hypotension. To this end, we employed an experimental model, in which the superior mesenteric arterial pressure (PSMA) was controlled by an adjustable perivascular clamp. This approach enabled us to keep the intestinal perfusion pressure (IPP) constant in the face of any systemic circulatory alterations. Methods: In 11 barbiturate-anesthetized pigs, we instrumented the superior mesenteric circulation for assessments of vascular resistance (RMES), IPP, jejunal mucosal perfusion (Laser Doppler) and intestinal tissue oxygenation (microoximetry). Measurements were carried out before and during dopexamine infusions (0.5 and 1.0 µg·kg,1·min,1) at a freely variable PSMA (i.e. the perivascular clamp fully open) and at a PSMA of 50 mmHg and 30 mmHg. Results: At a constant PSMA of 50 mmHg, dopexamine had no significant intestinal vascular effects. However, at a constant PSMA of 30 mmHg, both doses of dopexamine were associated with decreases in RMES. Effects of dopexamine on intestinal oxygen delivery and extraction were minimal during these procedures, while a minor decrease in intestinal tissue oxygen tension was observed during dopexamine administration at the lowest IPP level. Conclusion: At very low intestinal perfusion pressures (approximately 30 mmHg) dopexamine produces intestinal vasodilation in excess of what is produced by intrinsic autoregulation. This suggests that there is a vasodilatory reserve in the intestine under such conditions and that a pharmacological vasodilator like dopexamine may improve intestinal circulation during regional severe hypotension. [source] Activated macrophages in the tumour microenvironment,dancing to the tune of TLR and NF-,B,THE JOURNAL OF PATHOLOGY, Issue 2 2009Simon Hallam Abstract A large number of variables have been identified which appear to influence macrophage phenotype within the tumour microenvironment. These include reciprocal chemical and physical interactions with tumour cells and with non-malignant cells of the tumour microenvironment, tissue oxygen tension, and the origin and prior experience of the particular macrophage population. In this review we outline the key evidence for these influences and consider how macrophage phenotype is acquired and the relevance of the TLR,NF-,B pathway. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] PERIOPERATIVE HIGH-DOSE OXYGEN THERAPY IN VASCULAR SURGERYANZ JOURNAL OF SURGERY, Issue 6 2007Phillip J. Puckridge Background: Patients undergoing infrainguinal bypass surgery have reduced baseline tissue oxygen tension and high rates of wound infections. The hypoxaemia worsens during surgery, potentially reducing the ability to combat bacterial lodgement. We investigated whether high-dose perioperative oxygen administration to patients undergoing infrainguinal arterial surgery results in increased tissue oxygenation. Methods: Ten consecutive patients undergoing infrainguinal arterial surgery had transcutaneous partial pressure of oxygen (TcpO2) measured preoperatively, intraoperatively after arterial clamps applied, postoperatively and at discharge. Measurements were taken with inspired oxygen concentration (FiO2) of 30% then 80%. Arterial blood gases were measured at the same times. Results: Tissue oxygenation showed no difference intraoperatively while arterial clamps were in place, but significantly higher tissue oxygenation was seen with use of high-dose oxygen (FiO2 80%) postoperatively (P < 0.05). Carbon dioxide levels in tissue increased while arterial clamps were in place (P < 0.01) and pH fell intraoperatively and following reperfusion (P < 0.05). Conclusion: The administration of high-dose oxygen to vascular surgical patients undergoing lower-limb arterial surgery results in increased tissue oxygen concentrations when perfusion is not reduced by the presence of arterial clamps. These results suggest the administration of high-dose oxygen intraoperatively may be beneficial in reducing wound infections, but further research is required. [source] Authors' reply: Laparoscopic surgery impairs tissue oxygen tension more than open surgery (Br J Surg 2007; 94: 362,368)BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 7 2007E. Fleischmann No abstract is available for this article. [source] Laparoscopic surgery impairs tissue oxygen tension more than open surgeryBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 3 2007E. Fleischmann Background: Wound infection remains a common and serious complication after colonic surgery. Although many colonic operations are performed laparoscopically, it remains unclear whether this has any impact on the incidence of wound infection. Subcutaneous tissue oxygenation is an excellent predictor of surgical wound infection. The impact of open and laparoscopic colonic surgery on tissue oxygenation was compared. Methods: Fifty-two patients undergoing elective open and laparoscopic left-sided colonic resections were evaluated in a prospective observational study. Anaesthesia management was standardized and intraoperative arterial partial pressure of oxygen was kept at 150 mmHg in both groups. Oxygen tension was measured in the subcutaneous tissue of the right upper arm. Results: At the start of surgery subcutaneous tissue oxygen tension (PsqO2) was similar in both groups (mean(s.d.) 65·8(17·2) and 63·7(23·6) mmHg for open and laparoscopic operations respectively; P = 0·714). Tissue oxygen remained stable in the open group, but dropped significantly in the laparoscopic group during the course of surgery (PsqO2 after operation 53·4(12·9) and 45·5(11·6) mmHg, respectively; P = 0·012). Conclusion: Laparoscopic colonic surgery significantly decreases PsqO2, an effect that occurs early in the course of surgery. As tissue oxygen tension is a predictor of wound infection, these results may explain why the risk of wound infection after laparoscopic surgery remains higher than expected. Copyright © 2006 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] | ||||||||||