Anesthetic Preferences for Cardiac Anesthesia: A Survey of the Society of Cardiovascular Anesthesiologists

Abstract

Background:

Volatile anesthetics have been historically preferred for cardiac anesthesia, but the evidence for their superiority to intravenous agents is mixed. We conducted a survey to better understand the current state of practice and the rationale behind provider preferences for anesthesia for cardiac surgery with cardiopulmonary bypass. We hypothesized that anesthetic preference would vary considerably among surveyed providers without a clear majority, as would the rationale behind those preferences.

Methods:

Email invitations were sent to members of the Society of Cardiovascular Anesthesiologists. Members were asked to identify the anesthetics or sedatives they typically prefer to administer during induction, pre-bypass, bypass, post-bypass, and postoperative periods and why they prefer those agents. Members’ beliefs regarding the importance of anesthetics on postoperative outcomes were also assessed.

Results:

Invites were sent to 3,328 and 3,274 members on two separate dates, of which 689 (21%) responded. The median (IQR) respondent age was 45 (37, 56) years, 79% were male, and 75% were fellowship trained. The most frequently chosen drug for induction was propofol (80%). Isoflurane was the most frequently selected primary agent for the pre-bypass (57%), bypass (62%), and post-bypass periods (50%). Sevoflurane was the second most frequently selected (30%, 17%, and 24%, respectively). Propofol was the third most frequently selected agent for the bypass (14%) and post-bypass periods (17%). Ease of use was the most frequently selected reason for administering isoflurane and sevoflurane for each period. During bypass, the second most frequently selected rationale for using isoflurane and sevoflurane was institutional practice. 76% responded that the perfusionist typically delivers the on-bypass anesthetic. Ischemic preconditioning, organ protection, and postoperative cognitive function were infrequently selected as rationales for preferring the volatile anesthetics. Most respondents (73%) think that anesthetics have organ protective properties, especially isoflurane (74%) and sevoflurane (59%), and 72% believed that anesthetic choice contributes to patient outcome. The median (IQR) agreement (0=strongly disagree to 100=strongly agree]) was 72 (63, 85) for the statement that “inhaled anesthetics are an optimal maintenance anesthetic for cardiac surgery.”

Conclusion:

In a survey of cardiac anesthesiologists, a majority of respondents indicated they prefer volatile anesthetics for maintenance of anesthesia, that anesthetic selection impacts patient outcomes and that volatile anesthetics have organ protective properties. The members’ rationales for preferring these agents possibly reflect that practical considerations such as ease of use, effectiveness, and institutional practice also influence anesthetic selection during cardiac surgery in addition to considerations such as organ protection.

Introduction

Anesthesia for cardiac surgery is complex, balancing the core aims of general anesthesia with hemodynamic stability, preservation of myocardial function and organ protection, often in the unique context of cardiopulmonary bypass (CPB).¹ There are numerous anesthetics that may be used to achieve those goals, however a definite superior agent or approach has yet to be identified. Volatile anesthetic use during CPB was first described in 1974 and remained popular due to potential myocardial protective properties and the desire to avoid contemporary long-acting intravenous agents.^{1, 2} High-dose opioid use during cardiac anesthesia was first described as beneficial for patients with limited cardiovascular reserve in 1969, and the use of newer ultra-short acting opioids continues today.³ When propofol was introduced in the early 2000s, providers could opt for a short acting intravenous alternative to volatile agents and high dose opioids.

With the increasing availability of intravenous and volatile agents with similar anesthetic efficacy, investigations focused on potential differences in their non-anesthetic effects have sought to guide practice. For example, data from several small clinical trials suggest that preferential use of volatile agents may infer myocardial, renal, and cerebral protection.^4–6 The potential for volatile agents to prevent postoperative myocardial infarction after cardiac surgery led to the American College of Cardiologists and American Heart Association to recommend their use during non-cardiac surgery in the 2007 version of their guidelines for perioperative management.⁷ Additionally, volatile agents have been shown in some studies to reduce hospital and intensive care unit (ICU) length of stay, duration of mechanical ventilation, and mortality when compared to intravenous agents.^8–11 However, other clinical trials have found no differences in postoperative myocardial injury and mortality between volatile and intravenous anesthetic regimens.^{8, 10, 12, 13} Most notably, a recent multicenter single-blinded controlled trial compared volatile and intravenous anesthetics in 5400 cardiac surgery patients and found no difference in one-year mortality or myocardial infarction.¹⁴

Given these conflicting results, there remains considerable scientific equipoise regarding the superior anesthetic agent for cardiac surgery with CPB. It is unknown whether current practice reflects this uncertainty or whether particular approaches predominate. Furthermore, it is unknown whether the scientific rationales underlying the previously mentioned investigations and their findings influence providers’ anesthetic preferences as opposed to other factors. To help better understand the current state of practice and the rationale behind anesthetic selection, we conducted a survey of cardiac anesthesiologists. We hypothesized that anesthetic preference would vary considerably among surveyed providers without a clear majority, as would the rationale behind those preferences.

Methods

This prospective open survey was approved by the Beth Israel Deaconess Medical Center (BIDMC)’s Institutional Review Board (Protocol 2019P000331). This manuscript adheres to the applicable checklist for reporting results of internet e-surveys (CHERRIES) items. The survey questions were developed by two fellowship trained cardiac anesthesiologists (AK and SS), the study biostatistician (AM), and the primary investigator (BOG). Survey questions underwent multiple rounds of revisions among the investigators in an iterative process to determine the ideal format and sequencing and to minimize potential bias in the phrasing of responses. The electronic survey was tested for functionality and revised accordingly to improve usability, including the incorporation of a matrix format for questions involving similar answer options for multiple periods, branching logic to display follow-up questions only if the preceding relevant item was chosen, and automatic mandatory and missing items checks. Participants were allowed to back-navigate and change answers before submitting the completed survey. Before the study was launched a pilot test was performed in which three cardiac anesthesia fellows were asked to take the survey and provide feedback on usability, their understanding of the main objective of the survey, and on the phrasing of the answer choices. Ultimately the survey contained a maximum of 14 screens with questions, averaging 3–4 questions per page. On the first page of the survey link, a description of the background and purpose for the survey was provided, along with the estimated time needed to complete the study (5–10 minutes). Participants were notified that their entries would be de-identified. Afterwards participants provided informed consent via an electronic script. No incentives were offered for participation.

A proposal for the survey was reviewed and approved by the research committee for the Society of Cardiovascular Anesthesiologists and a final version was approved before dissemination to the membership. The society had no role in data handling, analysis, or manuscript preparation. Survey invites were sent via e-mail containing a link to a web-based survey hosted on the Research Electronic Data Capture (REDCap) platform by the society’s administration to all members of the Society of Cardiovascular Anesthesiologists with an active email registered. Invites were sent on 2/26/20 and 3/11/20. A full copy of the survey is available in the supplemental appendix (Supplemental Appendix 1).

The first page of the survey after the introduction page contained questions regarding the demographics of the participant, education levels and fellowship training (Supplemental Appendix 1: pages 2–3). Participants were also asked about their institution type, number of CPB cases performed at their institution per year as well as whether they practice concurrently in the intensive care unit (ICU). Participants were then asked to select the agent(s) they most commonly used for induction of anesthesia from a prespecified list of common induction agents and other medications typically given in the induction period (Supplemental Appendix 1 pages 4–6). Answer choices were framed in a “select all that apply” fashion.

For maintenance of anesthesia, participants were asked to select from prespecified lists for each of the pre-bypass, on-bypass, and post-bypass periods a single choice for their most commonly used primary agent, followed by any secondary agents (Supplemental Appendix 1: pages 7–14). They were also asked to select a rationale for their preference of primary agent from a prespecified list in a “select all that apply” fashion. Participants were also asked how they titrate their primary agent, again from a prespecified list. On the following screens providers’ beliefs regarding the importance of anesthetics on postoperative outcome and the potential organ protective properties of anesthetics were assessed with both yes/no and multiple-choice format questions. Additionally participants were asked to rate their agreement on a 0–100 scale (with zero indicating strongly disagree, 50 as neutral, and 100 as strongly agree) to the statements “Inhaled anesthetics are an optimal maintenance anesthetic for cardiac surgery”, “The potential protective properties of inhaled anesthetics outweigh the possibility of any adverse effects” and “More evidence is necessary before I feel comfortable declaring the inhaled anesthetics are the preferred agents for cardiac surgery.” Finally, participants were asked to select their most commonly used agents for postoperative sedation and ICU transport as well as the rationale behind these choices (Supplemental Appendix 1: page 17).

Statistical Analysis

Descriptive statistics of the data were generated for the entire cohort of respondents. Because of the possibility of missing data, especially for questions occurring toward the end of the survey instrument, denominators are present to identify missing data. No imputation was performed for missing data. Categorical data are presented as frequencies and proportions. Continuous data are presented as median (interquartile range [IQR]) given the skewed distributions observed. Normality of continuous data was assessed with a Shapiro-Wilk test and confirmed with visual inspections of the data. To make the presentation of the results more digestible for readers, the most common responses for each main category are presented. A post hoc analysis was conducted consisting of descriptive statistics on the demographics of current SCA members to compare how those of our sample may compare to the larger membership. Given the exploratory nature of the study, no hypothesis testing was performed. All descriptive statistics were generated using SAS 9.4 (SAS Institute Inc., Cary, NC).

Results

Demographics

Invites were sent to 3,328 and 3,274 members on two separate dates and there were 689 total survey responses, corresponding to a 21% response rate. The last response before the survey was closed was on 5/11/20. The median age of respondents was 45 years, with the majority being male, having graduated from a cardiac anesthesia fellowship, and practicing in urban teaching hospitals (Table 1). Coronary artery bypass graft and valve surgery (replacement or repair) were the most frequently selected case types. The highest percentage of respondents reported working at institutions where between 251–500 CPB cases were performed each year, and the next most frequent answer selected was working at institutions with greater than 1000 CPB cases per year. Results of the post hoc analysis demonstrated that the current SCA membership is also predominantly male and practicing in academic centers in the United States (Supplemental Table 1).

Table 1.

Demographics of survey participants

	Number Assessed	Respondents
Sex, No. (%)	598
Male		470 (78.60)
Female		126 (21.07)
Other		2 (0.33)
Age, Median (IQR)	557	45 (37, 56)
Education Level, No. (%)	592
MD or Equivalent		577 (97.47)
MPH		27 (4.56)
PhD		27 (4.56)
Other		18 (3.04)
Graduated from a Cardiac Anesthesia Fellowship, No. (%)	595	444 (74.62)
Practices in the ICU, No. (%)	596	125 (20.97)
Region, No. (%)	597
Northeast		151 (25.29)
Southeast		123 (20.60)
Midwest		105 (17.59)
West		74 (12.40)
Southwest		43 (7.20)
Other		101 (16.92)
Academic Hospital Status, No. (%)	589	349 (59.25)
Teaching Status, No. (%)	594
Urban Teaching		416 (70.03)
Urban Non-Teaching		137 (23.06)
Rural		41 (6.90)
Cases Involving CPB Performed Per Year, No. (%)	596
0 – 250		109 (18.29)
251 – 500		171 (28.69)
501 – 750		82 (13.76)
751 – 1000		96 (16.11)
>1000		138 (23.15)
Case Type, No. (%)	595
Adult		590 (99.16)
Pediatrics		85 (14.29)
Commonly Performs Solo Cases, No. (%)	595	240 (40.34)
Supervising Coverage Ratio, No. (%)	576
1:1		249 (43.23)
1:2		113 (19.62)
1:3		54 (9.38)
1:4		27 (4.69)
Never Supervises		133 (23.09)
Individuals They Supervise, No. (%)	355
Residents		276 (77.75)
Fellows		184 (51.83)
CRNAs		169 (47.61)
Never Supervises		1 (0.28)
Cases Typically Performed, No. (%)	597
CABG		587 (98.32)
Valve		588 (98.49)
Combined		562 (94.14)
Congenital		156 (26.13)
Aortic		549 (91.96)
LVAD		306 (51.26)
Transplant		233 (39.03)
Other		66 (11.06)
Typically Administers the On-Bypass Anesthetic, No. (%)	531
Anesthesia Provider		144 (27.12)
Perfusionist		448 (84.37)

Abbreviations: IQR = interquartile range, CPB = cardiopulmonary bypass, MD = Doctor of Medicine, MPH = master of public health, PhD = Doctor of Philosophy, CRNA = certified registered nurse anesthetist, CABG = coronary artery bypass grafting, LVAD = left ventricular assist device

Anesthetic Induction

The most frequently chosen drug for induction was propofol (Figure 1). Ease of use and effectiveness were the two most common reasons given for preferring propofol. Fentanyl was the second most frequently chosen drug for induction with hemodynamic stability and effectiveness cited as the most common rationales for their preference. Midazolam was the third most frequently chosen drug for induction with effectiveness and hemodynamic stability most frequently given as rationales. Our questionnaire did not directly ask respondents to name the combinations of drugs they most commonly use, but we analyzed the combinations of drugs selected by respondents to determine the most frequent responses consisting of multiple agents. The most frequently selected two-drug combination for induction was propofol and fentanyl and the most frequent three-drug combination for induction was propofol, fentanyl and midazolam. Etomidate was selected by 27% respondents as an agent most commonly used during induction (data not shown) and was a component of the second most frequently selected three-drug combination, namely etomidate, fentanyl and midazolam. Sufentanyl was selected by 15% of respondents (data not shown).

Figure 1. Preferred anesthetics for induction and rationale.

Panel A depicts the most commonly selected anesthetic agents during induction (left; 591 responses), and the most commonly selected two- (middle) and three-drug (right) combinations

Panel B depicts the top three rationales for the three most commonly selected induction agents: propofol (left; 464 responses), fentanyl (middle; 418 responses) and midazolam (right; 332 responses).

Anesthetic Maintenance

The most frequently selected primary agents in the pre-bypass period were isoflurane, sevoflurane, fentanyl and propofol (Figure 2). The most frequently selected primary agents in the bypass period were isoflurane, sevoflurane and propofol. The most frequently selected primary agents in the post-bypass period were isoflurane, sevoflurane and propofol.

Figure 2. Preferred primary anesthetics for maintenance of anesthesia.

Preferred agents during during the pre-bypass (562 responses), bypass (554 responses) and post-bypass periods (554 responses) are reported.

Ease of use was the most frequently selected reason in each period for administering isoflurane as well as for sevoflurane (Figure 3). During cardiopulmonary bypass, the second most frequently selected rationale was institutional practice for both isoflurane and sevoflurane. Of note, 76% of participants responded that the perfusionist typically administers the on-bypass anesthetic (data not shown). Infrequently selected rationale options for the volatile anesthetics included ischemic preconditioning (isoflurane, pre-bypass: 15%; bypass: 21%; and post-bypass: 9%), cardiac organ protection (17%, 32%, and 13% respectively), pulmonary organ protection (2%; 6%; and 5%) and postoperative cognitive function (2%, 9%, and 19%) (data not shown).

Figure 3. Rationales underlying provider preferences for a given primary maintenance anesthetic.

Each panel depicts the three most commonly selected rationales for the top three primary anesthetics preferred by members during defined periods of a typical case

Panel A (pre-bypass period): isoflurane (303 responses), sevoflurane (164 responses), and fentanyl (39 responses).

Panel B (on-bypass period): isoflurane (323 responses), sevoflurane (87 responses), and propofol (77 responses).

Panel C (post-bypass period):isoflurane (266 responses), sevoflurane (122 responses) and propofol (86 responses).

The most commonly preferred secondary agents for the pre-bypass period were fentanyl (61%), midazolam (21%) and propofol (16%) (data not shown). Frequently selected secondary agents during bypass included fentanyl (39%), midazolam (20%) and dexmedetomidine (20%). The most commonly selected secondary agents for the post-bypass period were dexmedetomidine (36%), fentanyl (35%) and propofol (24%).

Agent Titration

During the pre-bypass period, hemodynamics was the most frequently selected titration method for isoflurane (80%) and sevoflurane (80%), as well as for fentanyl (78%) (data not shown). Minimum alveolar concentration (MAC) was the second most frequently selected titration method for all three agents (isoflurane: 68%; sevoflurane: 63%; and fentanyl 40%). Hemodynamics was also the most frequently selected titration method for those who preferred inhaled agents during bypass (isoflurane: 57%, sevoflurane: 67%), with bispectral index (BIS) the second most frequently selected (40% and 55%, respectively). MAC was the third most frequently selected titration method during bypass for both isoflurane (31%) and sevoflurane (34%). BIS was the most frequently selected titration method on bypass for members who indicated propofol as their preferred primary agent (73%). During the post-bypass period, hemodynamics was also the most frequently selected titration method for both inhaled agents isoflurane (81%) and sevoflurane (83%), as well as for propofol (76%). MAC was the second most frequently selected post-bypass method of titration for those preferring either isoflurane (64%) or sevoflurane (61%) while BIS was the second most frequently selected for those who preferred propofol as their primary post-bypass agent (67%).

Importance of Anesthetic Selection

The majority of respondents indicated that anesthetic choice contributes to patient outcomes (Table 2). Seventy three percent of respondents indicated that they think anesthetics have organ protective properties, especially isoflurane, sevoflurane and propofol. When asked what period of the case was critical for organ protection, the most frequently selected response was that all periods of the case are equally critical for organ protection, followed by the pre-bypass period and during CPB. Finally, there was moderate agreement with the statement “inhaled anesthetics are an optimal maintenance anesthetic for cardiac surgery” and “the potential protective properties of inhaled anesthetics outweigh the possibility of any adverse effects” whereas respondents were neutral when asked whether “more evidence is necessary before I feel comfortable declaring the inhaled anesthetics are the preferred agents for cardiac surgery.”

Table 2.

The importance of anesthetic selection on outcomes and organ protection

	Number Assessed	Respondents
Respondent Believes Anesthetic Choice Contributes to Patient Outcome, No. (%)	521	376 (72.17)
Respondent Indicated the Following Period(s) were Most Influential on Outcome, No. (%)	374
Pre-Bypass		129 (34.49)
On-Bypass		60 (16.04)
Post-Bypass (Anytime)		92 (24.60)
Post Reperfusion (Removal of Cross Clamp)		38 (10.16)
Post Chest Closure		27 (7.22)
ICU Transport		39 (10.43)
All Periods are Equally Important		217 (58.02)
Respondent Believes Anesthetic Agents Have Organ Protective Properties, No. (%)	516	376 (72.87)
Respondent Believes the Following Agent(s) Have Organ Protective Properties, No. (%)	370
Propofol		128 (34.59)
Isoflurane		274 (74.05)
Sevoflurane		220 (59.46)
Desflurane		70 (18.92)
Narcotics		78 (21.08)
Other		32 (8.65)
Respondent Believes the Following Period is Most Critical for Organ Protection, No. (%)	371
Pre-Bypass		112 (30.19)
On-Bypass		80 (21.56)
Post-Bypass (Anytime)		3 (0.81)
Post Reperfusion (Removal of Cross Clamp)		23 (6.20)
Post Chest Closure		2 (0.54)
ICU Transport		2 (0.54)
All Periods are Equally Important		149 (40.16)
Respondents Level of Agreement to the Following Statements, (0: Strongly Disagree, 100: Strongly Agree), Median (IQR)
Inhaled anesthetics are an optimal maintenance anesthetic for cardiac surgery	446	72 (63, 85)
The potential protective properties of inhaled anesthetics outweigh the possibility of any adverse effects.	401	67 (50, 78)
More evidence is necessary before I feel comfortable declaring the inhaled anesthetics are the preferred agents for cardiac surgery.	401	50 (28, 70)

Postoperative Sedation

Propofol (50%) was the most commonly chosen primary agent for postoperative sedation during ICU transport with ease of use (88%) as the most frequently selected rationale (data not shown). Dexmedetomidine (42%) was the second most selected option, with sedative efficacy (63%) being the most frequently selected rationale. Notably, 8% of respondents indicated that they typically extubate in the operating room.

Discussion

In an online survey of members of the Society of Cardiovascular Anesthesiologists, we found that the respondents employ various agents or combinations of agents at different timepoints during a typical case. Although there were many different primary agents preferred by the respondents, a clear majority prefer volatile anesthetics for maintenance of anesthesia during cases with CPB, a time period critical for perioperative organ protection that has been the subject of multiple investigations to determine the potential role of the anesthetic in postoperative outcomes. A smaller proportion prefers propofol or other intravenous anesthetics. We found that practical considerations such as ease of use, effectiveness, or institutional practice predominated over other proposed rationales for anesthetic preference such as ischemic preconditioning, organ protection or postoperative cognitive function. Hemodynamics was the most commonly selected method of anesthetic titration during CPB especially for the inhaled agents, and for both the inhaled agents and propofol in the post-bypass period, with MAC and BIS less frequently selected. There was agreement among respondents that the choice of anesthetic contributes to patient outcome and that anesthetic agents have organ protective properties. Lastly, there was agreement that inhaled anesthetics are the optimal agents for maintenance of anesthesia during cardiac surgery and that their potential protective properties outweigh the possibility of any adverse events. Our study is novel in that it attempts to describe the current state of practice for cardiac anesthesiologists using a large sample of providers and adds additional value by describing providers’ rationales underlying these practice patterns.

A recent systematic review on anesthetic management during CPB stated that the use of volatile agents predominates in North America and intravenous agents are more common in Europe, citing personal communications with colleagues.² Our findings both confirm and add substantially to this review, providing a quantifiable estimate of the preference for volatile agents in a large sample of providers mainly from the United States. In Europe, the use of intravenous anesthetics during CPB likely arises from a European Council Directive prohibiting the attachment of an anesthetic vaporizer to a CPB machine.¹⁵ Similar logistics may also shape the anesthetic preferences for our respondents, however in this case in favor of the volatile agents given the demographics of our sample. Additionally, it is notable that the majority indicated that the perfusionist delivers the on-bypass anesthetic. In certain practices, the choice of agent may be similarly reduced to what has been conventionally done at that institution, or what is available.

Data from both preclinical and clinical studies have sought to identify whether intravenous or volatile agents are superior for cardiac anesthesia. Numerous studies suggest that volatile anesthetics protect against postoperative organ dysfunction and are associated with shorter ICU length of stay, lower postoperative troponin levels and rates of postoperative myocardial infarction, and reduced mortality when compared to the use of intravenous agents.^{4–6, 9–11, 16–18} On the other hand, other studies suggest that there is no difference between volatile and inhaled anesthetics in hospital and ICU length of stay, postoperative troponin levels, rates of myocardial infarction and mortality.^{8, 10, 12–14} Most notable among these is the recent trial demonstrating no difference in postoperative mortality or multiple secondary outcomes including myocardial infarction for 5400 patients randomized to inhaled or total intravenous anesthesia.¹⁴ These conflicting findings may stem from differences in trial protocols and a failure of positive results in surrogate outcomes to translate to differences in rare outcomes like postoperative mortality, but nonetheless this leaves the question of the ideal agent for cardiac anesthesia as of yet unanswered.

Given the lack of evidence clearly supporting one anesthetic approach we hypothesized that current anesthetic practice may reflect this uncertainty. Furthermore, we anticipated that the reasons why providers chose certain anesthetics would vary considerably, possibly reflecting the proposed benefits for certain agents such as ischemic preconditioning or organ protection, or that provider preference may possibly reflect logistical or practical considerations. Our findings suggest, however, that volatile agents are predominantly preferred for anesthetic maintenance among the respondents in our sample. Additionally, they suggest that considerations such as ease of use and institutional practice may also contribute to the anesthetic preferences of providers, perhaps more so than organ protection and ischemic preconditioning. Perhaps this result reflects that providers may be opting for the conventional approach with inhaled anesthetics in lieu of one that has not proven superior. Of course, there is the potential that future investigations could identify a superior cardiac anesthetic agent, and then over time ideally this would become the institutional standard if a change in practice is warranted by the evidence.

Our findings should be interpreted in the context of the study’s limitations. First, we only surveyed members of one professional society composed mainly of providers in urban academic centers in the United States. This limits the generalizability of our findings in international settings and smaller centers. Second, our study had a response rate of 21%, which, although is above the range of 10–13% that is typical of the response rates of physicians from online surveys, may nonetheless result in nonresponse bias.^19–21 The number of participants who completed each section decreased as the survey went on, subjecting answers from those later sections to increasing non-response bias. Further, it is possible that the way we formulated our answer choices might have prompted respondents to select “conventional” or “safe” answers such as ease of use and institutional practice. The consistent ordering of our answer choices might bias respondents to pick these options before reading through all the other answer choices. We considered randomizing the order of responses but elected not to do so to facilitate completion of a complex survey containing multiple questions where answer options could be presented uniformly. Future surveys of anesthetic practice patterns could account for this by randomizing the order of answer choices.

In conclusion, our study suggests that the inhaled anesthetics are predominantly used for maintenance of anesthesia for cardiac surgery with CPB despite ongoing scientific equipoise as to their superiority. Practical considerations appear to influence anesthetic preferences as much if not more so than rationales proposed from preclinical and human studies. Thus, future investigations or efforts seeking to guide practice by identifying the superiority of a particular agent should keep these additional barriers to practice change in mind if a change is recommended.

Key Points:

Question:

Among members of the Society of Cardiovascular Anesthesiologists, what are the preferred anesthetics for a typical case with cardiopulmonary bypass, and why are those agents preferred?

Findings:

Clear preferences for isoflurane and sevoflurane during maintenance of anesthesia including during cardiopulmonary bypass were evident, and ease of use and institutional practice were most frequently selected as the rationales for their use as compared to ischemic preconditioning, organ protection, or postoperative cognition which were rarely selected.

Meaning:

In the midst of ongoing scientific equipoise as to the optimal anesthetic for cardiac surgery, respondents from a society of cardiac anesthesiologists mainly from the United States prefer the volatile agents for both practical and clinical reasons.

Glossary of Terms:

IQR

Interquartile range

CPB

Cardiopulmonary bypass

REDCap

Research electronic data capture

ICU

Intensive care unit

MAC

Minimum alveolar concentration

BIS

Bispectral Index