Clinical Trials Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Jan 18, 2017; 8(1): 49-56
Published online Jan 18, 2017. doi: 10.5312/wjo.v8.i1.49
Microvascular response to transfusion in elective spine surgery
J Matthias Walz, Ottokar Stundner, Federico P Girardi, Bruce A Barton, Aimee R Koll-Desrosiers, Stephen O Heard, Stavros G Memtsoudis
J Matthias Walz, Stephen O Heard, Department of Anesthesiology and Perioperative Medicine, UMass Memorial Healthcare, Worcester, MA 01655, United States
Ottokar Stundner, Department of Anesthesiology, Hospital for Special Surgery, Weill Cornell Medical Center, New York, NY 10021, United States
Ottokar Stundner, Department of Anesthesiology, Perioperative Medicine and Intensive Care Medicine, Paracelsus Medical University, 5020 Salzburg, Austria
Federico P Girardi, Department of Orthopedic Surgery, Hospital for Special Surgery, Weill Cornell Medical Center, New York, NY 10021, United States
Bruce A Barton, Aimee R Kroll-Desrosiers, Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, MA 01655, United States
Stavros G Memtsoudis, Department of Anesthesiology, Hospital for Special Surgery, Weill Cornell Medical Center, New York, NY 10021, United States
Author contributions: Walz JM, Heard SO and Memtsoudis SG designed the research; Girardi FP, Stundner O and Memtsoudis SG conducted the research; Barton BA and Kroll-Desrosiers AR developed the statistical model and performed all statistical analysis; all authors analyzed and interpreted the data; Walz JM wrote the first draft of the manuscript; all authors revised the manuscript, approved the final manuscript, and are accountable for all aspects of the work; Walz JM is the guarantor of the manuscript and takes full responsibility for the integrity of the work as a whole, from inception to published article.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board at the Hospital for Special Surgery, NY.
Informed consent statement: All study participants provided informed written consent prior to study enrollment.
Conflict-of-interest statement: None of the authors has any conflicts of interest relevant to this study.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: J Matthias Walz, MD, Department of Anesthesiology and Perioperative Medicine, UMass Memorial Healthcare, 55 Lake Avenue North, Worcester, MA 01655, United States. matthias.walz@umassmemorial.org
Telephone: +1-508-8563266
Received: June 12, 2016
Peer-review started: June 17, 2016
First decision: July 18, 2016
Revised: August 21, 2016
Accepted: October 25, 2016
Article in press: October 27, 2016
Published online: January 18, 2017
Processing time: 212 Days and 11.3 Hours
Abstract
AIM

To investigate the microvascular (skeletal muscle tissue oxygenation; SmO2) response to transfusion in patients undergoing elective complex spine surgery.

METHODS

After IRB approval and written informed consent, 20 patients aged 18 to 85 years of age undergoing > 3 level anterior and posterior spine fusion surgery were enrolled in the study. Patients were followed throughout the operative procedure, and for 12 h postoperatively. In addition to standard American Society of Anesthesiologists monitors, invasive measurements including central venous pressure, continual analysis of stroke volume (SV), cardiac output (CO), cardiac index (CI), and stroke volume variability (SVV) was performed. To measure skeletal muscle oxygen saturation (SmO2) during the study period, a non-invasive adhesive skin sensor based on Near Infrared Spectroscopy was placed over the deltoid muscle for continuous recording of optical spectra. All administration of fluids and blood products followed standard procedures at the Hospital for Special Surgery, without deviation from usual standards of care at the discretion of the Attending Anesthesiologist based on individual patient comorbidities, hemodynamic status, and laboratory data. Time stamps were collected for administration of colloids and blood products, to allow for analysis of SmO2 immediately before, during, and after administration of these fluids, and to allow for analysis of hemodynamic data around the same time points. Hemodynamic and oxygenation variables were collected continuously throughout the surgery, including heart rate, blood pressure, mean arterial pressure, SV, CO, CI, SVV, and SmO2. Bivariate analyses were conducted to examine the potential associations between the outcome of interest, SmO2, and each hemodynamic parameter measured using Pearson’s correlation coefficient, both for the overall cohort and within-patients individually. The association between receipt of packed red blood cells and SmO2 was performed by running an interrupted time series model, with SmO2 as our outcome, controlling for the amount of time spent in surgery before and after receipt of PRBC and for the inherent correlation between observations. Our model was fit using PROC AUTOREG in SAS version 9.2. All other analyses were also conducted in SAS version 9.2 (SAS Institute Inc., Cary, NC, United States).

RESULTS

Pearson correlation coefficients varied widely between SmO2 and each hemodynamic parameter examined. The strongest positive correlations existed between ScvO2 (P = 0.41) and SV (P = 0.31) and SmO2; the strongest negative correlations were seen between albumin (P = -0.43) and cell saver (P = -0.37) and SmO2. Correlations for other laboratory parameters studied were weak and only based on a few observations. In the final model we found a small, but significant increase in SmO2 at the time of PRBC administration by 1.29 units (P = 0.0002). SmO2 values did not change over time prior to PRBC administration (P = 0.6658) but following PRBC administration, SmO2 values declined significantly by 0.015 units (P < 0.0001).

CONCLUSION

Intra-operative measurement of SmO2 during large volume, yet controlled hemorrhage, does not show a statistically significant correlation with either invasive hemodynamic, or laboratory parameters in patients undergoing elective complex spine surgery.

Keywords: Transfusion; Complex spine surgery; Near infrared spectroscopy; Microvascular blood flow; Hemodynamic monitoring

Core tip: Tissue oxygenation determined by Near Infrared Spectroscopy has been used to assess the adequacy of end-organ perfusion in models of trauma and sepsis and has been shown to correlate with stroke volume in models of hemorrhagic shock. We sought to investigate muscle tissue oxygenation (SmO2) during transfusion in patients undergoing complex spine surgery, and to study the association of SmO2 with invasive hemodynamic parameters in the clinical setting. In our study, we were unable to demonstrate a statistically significant correlation between SmO2 and either invasive hemodynamic, or laboratory parameters in patients undergoing elective complex spine surgery.