Authors: Robert E. Freundlich, M.D., M.S.; Adam J. Kingeter, M.D.
Anesthesiology 11 2017, Vol.127, 901-902. doi:10.1097/ALN.0000000000001852
To the Editor:
We read with great interest the manuscript in the March 2017 issue of Anesthesiology by Mathis et al.1 that provided an overview of the authors’ experiences managing patients with left ventricular assist devices (LVADs) who were undergoing noncardiac surgery. We would propose that there are no straightforward anesthetics for LVAD patients and that all cases performed on LVAD patients should be considered higher risk. In this context, risk stratification is unnecessary and, if anything, may lead to an increased sense of complacency when managing a “low-risk” LVAD patient—there is no such thing.
Certain elements of the anesthetic planning should reflect this increased risk. For example, only 20.1% of the anesthetics described by Mathis et al. involved placement of an arterial line. Given their diminished pulsatile flow and the complex physiologic changes that may occur in the LVAD heart undergoing sedation and anesthesia, we would argue that this percentage should be much higher, even in cases not involving general anesthesia. Not only does the arterial line display an accurate reflection of blood pressure and pulsatility, the waveform itself can yield valuable information about volume status.2 The authors’ observation that 5.5% of cases were performed without any recorded blood pressure (invasive or noninvasive) further highlights the importance of having a low threshold to place a reliable intraarterial blood pressure monitor. Additionally, the fact that 55% of cases had a more than 20-min intraoperative gap without recorded blood pressures is of particular concern, as duration of intraoperative hypotension has been shown to correlate with acute kidney injury, among other adverse outcomes.3,4 Given the low incidence of complications associated with radial arterial line placement and the high incidence of intraoperative hypotension in this population, we would argue that arterial line placement is underutilized in the perioperative management of these patients.5
Robert E. Freundlich, M.D., M.S., Adam J. Kingeter, M.D. Vanderbilt University Medical Center, Nashville, Tennessee (R.E.F.). firstname.lastname@example.org
Mathis, MR, Sathishkumar, S, Kheterpal, S, Caldwell, MD, Pagani, FD, Jewell, ES, Engoren, MC . Complications, risk factors, and staffing patterns for noncardiac surgery in patients with left ventricular assist devices. Anesthesiology 2017; 126:450–60
Kawahito, S, Takano, T, Nakata, K, Maeda, T, Nonaka, K, Linneweber, J, Schulte-Eistrup, S, Sato, T, Mikami, M, Glueck, J, Nosé, Y . Analysis of the arterial blood pressure waveform during left ventricular nonpulsatile assistance in animal models. Artif Organs 2000; 24:816–20
Walsh, M, Devereaux, PJ, Garg, AX, Kurz, A, Turan, A, Rodseth, RN, Cywinski, J, Thabane, L, Sessler, DI . Relationship between intraoperative mean arterial pressure and clinical outcomes after noncardiac surgery: Toward an empirical definition of hypotension. Anesthesiology 2013; 119:507–15
Sun, LY, Wijeysundera, DN, Tait, GA, Beattie, WS . Association of intraoperative hypotension with acute kidney injury after elective noncardiac surgery. Anesthesiology 2015; 123:515–23
Nuttall, G, Burckhardt, J, Hadley, A, Kane, S, Kor, D, Marienau, MS, Schroeder, DR, Handlogten, K, Wilson, G, Oliver, WC . Surgical and patient risk factors for severe arterial line complications in adults. Anesthesiology 2016; 124:590–7