Bennett-Guerrero E, Lockhart EL, Bandarenko N, Campbell ML, Natoli MJ, Jamnik VK, Carter TR, Moon RE. A Randomized Controlled Pilot Study of VO2 Max Testing: A Potential Model for Measuring Relative In Vivo Efficacy of Different Red Blood Cell Products. Transfusion. 2016 Nov 23. [Epub ahead of print]
BACKGROUND: Randomized trials, for example, RECESS, comparing “young” (median, 7-day) versus “middle-aged” (median, 28-day) red blood cells (RBCs), showed no difference in outcome. These data are important; however, they do not inform us about the safety and effectiveness of the oldest RBCs, which some patients receive. It may not be feasible to conduct a clinical trial randomizing patients to receive the oldest blood. Therefore, we propose strenuous exercise (VO2 max testing) as a model to study the relative efficacy to increase oxygen delivery to tissue of different RBC products, for example, extremes of storage duration.
STUDY DESIGN AND METHODS: In this pilot study, eight healthy subjects had 2 units of leukoreduced RBCs collected by apheresis in AS-3 using standard methods. Subjects were randomized to receive both (2) units of their autologous RBCs at either 7 or 42 days after blood collection. VO2 max testing on a cycle ergometer was performed 2 days before (Monday) and 2 days after (Friday) the transfusion visit (Wednesday). This design avoids confounding effects on intravascular volume from the 2-unit blood transfusion. The primary outcome was the difference in VO2 max between Friday and Monday (delta VO2 max).
RESULTS: VO2 max increased more in the 7-day RBC arm (8.7 ± 6.9% vs. 1.9 ± 6.5%, p = 0.202 for comparison between arms). Exercise duration (seconds) increased in the 7-day RBC arm (8.4 ± 1.7%) but actually decreased in the 42-day arm (-2.6 ± 3.6%, p = 0.002).
CONCLUSIONS: This pilot study suggests that VO2 max testing has potential as a rigorous and quantitative in vivo functional assay of RBC function. Our preliminary results suggest that 42-day RBCs are inferior to 7-day RBCs at delivering oxygen to tissues.
Cobey FC, Ferreira R, Ursprung WW, Karhausen J, Swaminathan M, Mackensen GB. A Novel Approach to Assess the Three-Dimensional Anatomy of a Mitral Valve Regurgitant Jet Orifice. J Cardiothorac Vasc Anesth. 2016 Sep 13. pii: S1053-0770(16)30386-X. [Epub ahead of print]
Ilfeld BM, Grant SA, Gilmore CA, Chae J, Wilson RD, Wongsarnpigoon A, Boggs JW. Neurostimulation for Postsurgical Analgesia: A Novel System Enabling Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation. Pain Pract. 2016 Dec 2. [Epub ahead of print]
While neurostimulation-stimulation of the nervous system using electrical current-has been used to treat chronic pain, its use treating postsurgical pain has been limited. Here we report on the clinical application of a novel investigational lead to provide analgesia following total knee arthroplasty. In 5 subjects, leads were inserted percutaneously using ultrasound guidance within 0.5 to 3.0 cm of the femoral and/or sciatic nerve(s). With the delivery of current, pain decreased an average of 63% at rest, with 4 of 5 subjects having relief of >50%. During passive and active knee flexion, pain decreased an average of 14% and 50%, with 0/3 and 1/2 subjects attaining >50% relief, respectively. Ultrasound-guided percutaneous peripheral nerve stimulation may be a practical modality for the treatment of postsurgical pain.