Non-invasive and invasive measurement of skeletal muscular oxygenation during isolated limb perfusion.

BACKGROUND: Isolated limb perfusion (ILP) is a regional surgical treatment for localized metastatic disease. High doses of chemotherapeutic agents are administered within an extracorporeal circulated isolated extremity, treating the metastasis, while systemic toxicity is avoided. To our knowledge, indexed oxygen supply/demand relationship during ILP has not previously been described. Our aim was to measure and describe oxygen metabolism, specifically oxygen delivery, consumption, and extraction, in an isolated leg/arm during ILP. Also investigate whether invasive oxygenation measurement during ILP correlates and can be used interchangeable with the non-invasive method, near infrared spectroscopy (NIRS). METHODS: Data from 40 patients scheduled for ILP were included. At six time points blood samples were drawn during the procedure. DO2, VO2, and O2ER were calculated according to standard formulas. NIRS and hemodynamics were recorded every 10 min. RESULTS: For all observations, the mean of DO2 was 190±59 ml/min/m2, VO2 was 35±8 ml/min/m2, and O2ER was 21±8%. VO2 was significantly higher in legs compared to arms (38±8 vs. 29±7 ml/min/m2, p=0.02). Repeated measures showed a significant decrease in DO2 in legs (209±65 to 180±66 ml/min/m2, p=<0.01) and in arms (252±72 to 150±57 ml/min/m2, p=<0.01). Significant increase in O2ER in arms was also found (p=0.03). Significant correlation was detected between NIRS and venous extremity oxygen saturation (SveO2) (rrm=0.568, p=<. 001, 95% CI 0.397-0.701). When comparing SveO2 and NIRS using a Bland-Altman analysis, the mean difference (bias) was 8.26±13.03 (p=<. 001) and the limit of agreement was - 17.28-33.09, with an error of 32.5%. CONCLUSION: DO2 above 170 ml/min/m2 during ILP kept O2ER below 30% for all observations. NIRS correlates significant to SveO2; however, the two methods do not agree sufficiently to work interchangeable. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT04460053 and NCT03073304.

Whole Blood Adsorber During CPB and Need for Vasoactive Treatment After Valve Surgery in Acute Endocarditis: A Randomized Controlled Study.

OBJECTIVES: Patients with endocarditis requiring urgent valvular surgery with cardiopulmonary bypass are at a high risk of developing systemic inflammatory response syndrome and septic shock, necessitating intensive use of vasopressors after surgery. The use of a cytokine hemoadsorber (CytoSorb, CytoSorbents Europe GmbH, Germany) during cardiac surgery has been suggested to reduce the risk of inflammatory activation. The study authors hypothesized that adding a cytokine adsorber would reduce cytokine burden, which would translate into improved hemodynamic stability. DESIGN: A randomized, controlled, nonblinded clinical trial. SETTING: At a university hospital, tertiary referral center. PARTICIPANTS: Nineteen patients with endocarditis undergoing valve surgery. INTERVENTION: A cytokine hemoadsorber integrated into the cardiopulmonary bypass circuit. MEASUREMENTS AND MAIN RESULTS: The accumulated norepinephrine dose in the intervention group was half or less at all postoperative time points compared to the control group, although it did not reach statistical significance; at 24 and 48 hours (median 36 [25-75 percentiles; 12-57] µg v 114 [25-559] µg, p = 0.11 and 36 [12-99] µg v 261 [25-689] µg, p = 0.09). There was no significant difference in chest tube output, but there was a significantly lower need for the transfusion of red blood cells (285 [0-657] mL v 1,940 [883-2,148] mL, p = 0.03). CONCLUSIONS: There was no statistically significant difference between the groups with regard to vasopressor use after surgery for endocarditis with the use of a cytokine hemoadsorber during cardiopulmonary bypass. Additional, larger randomized controlled trials are needed to definitely assess the potential effect.