The Journal of ExtraCorporeal Technology Issue 55-1 | Page 12

4 B . Lohbusch et al .: J Extra Corpor Technol 2023 , 55 , 3 – 22

Materials and methods

Following exempt status approval from the Institutional Review Boards ( IRB ) of the University of Michigan ( HUM00194742 ) and the Medical University of South Carolina ( Pro00107747 ), an 81-question , the closed-question survey was distributed through the Research Electronic Data Capture ( REDCap ; Nashville , TN ). REDCap is a web-based and secure application for data capture and clinical research database development [ 15 ]. The survey topics included program staffing and demographics , equipment , techniques and monitoring , and clinical protocols ( Appendix ). The unit of analysis were centerlevel adult cardiovascular perfusion programs located in the eastern and mid-Atlantic regions of the United States . A database repository consisting of chief perfusionists ( or designee ) contact information from programs located in the Zone IV region of AmSECT was previously collected and maintained at the University of Michigan ( Cardiovascular Perfusion Data

Repository : Submission ID : REP00000060 ). AmSECT Zone

IV comprises 15 states and the District of Columbia across the eastern region of the United States , ranging from Maine to South Carolina . A total of 234 cardiac surgical programs were identified in the Zone IV region ( Appendix ).

The survey questionnaire requested program and procedural data that described clinical practice for the 2020 calendar year . Several questions were also included to identify practice trends over the previous three-year period . Subjects were recruited directly via email invitation on June 8th , 2021 . The survey invitation remained open for five weeks , with a closure date of July 16th , 2021 . To maximize response rates , non-respondent subjects received up to three notices for participation prior to survey closure . The initial survey was sent to 234 cardiac institutions ; however , removing pediatric programs , duplicate or erroneous entries , and missing data resulted in 167 confirmed centers .

Descriptive statistics were used to analyze survey responses . Responses collected from the University of Michigan REDCap repository were de-identified by a database analyst and provided to study investigators . De-identified data were imported into SPSS ( IBM SPSS Statistics for Macintosh , Version 27.0 , Armonk , NY : IBM Corp .) for analysis and reporting of completed surveys .

Results

Responses were received from 58 of 167 centers for an overall response rate of 34.7 %. Survey responses were received from 13 states with the number of responses between states ranging from 1 to 16 ( Table 1 ). Pennsylvania , New Jersey , New York , and Massachusetts represented 67.3 % ( n = 39 ) of the responses received .

Staffing and demographics

Thirty-two ( 55.2 %) centers reported performing 600 CPB procedures or less in 2020 , with 16 ( 28 %) reporting less than 300 ( Figure 1 ). Centers performing 150 CPB standby or less were reported in 35 ( 60.3 %) of responses ( Figure 2 ). The reported distribution of surgical case type is reported in Figure 3 .

Table 1 . Number of respondents and location ( n = 58 ).

The most frequently reported surgical procedures were coronary artery bypass grafting ( CABG ) and valve repair / replacement procedures ( n = 57 , 98.3 %). Most programs reported the use of both veno-arterial ( VA ) and veno-venous ( VV ) extracorporeal membrane oxygenation ( ECMO ) support ( 91.4 % and 87.9 %, respectively ). The least frequent surgical procedures reported were ex-vivo lung perfusion ( n = 1 , 1.7 %) and organ procurement during transplant ( n = 3,5.2 %).

The mean number of full-time perfusionists was 6.43 , with teams ranging from 1 to 33 perfusionists ( Figure 4 ). Eleven programs ( 19 %) had part-time perfusionists on staff , with 32 ( 55.2 %) reporting the use of per diem or locum tenens coverage over the previous three years . Most respondents ( n = 43 , 72.4 %) indicated that the annual number of clinical hours provided by the perfusion team had increased from 2017 to 2020 .

The n + 1staffing model , as defined by Guideline 15.1 in the AmSECT Standards and Guidelines for Perfusion Practice , establishes the minimum safe number of perfusion staff required to support operating rooms at any one given time per surgical center [ 7 ]. This guideline calls for the presence of one staff member above the number of procedures underway [ 7 ]. Respondents reported implementing N + 1 during the elective schedule in 50 % ( n = 29 ) of centers . A total of 4 ( 6.9 %) respondents indicated using more than the n + 1 , and nine programs ( 15.5 %) reported staffing the minimum 1 perfusionist per procedure . The use of the n + 1 model for both elective scheduled and off-hour procedures was reported by 14 ( 24 %) of respondents .

Equipment

Survey response rate (%)

n – number of center respondents , N – number of state centers , % – percent responses . Centrifugal pumps were reported at 47 ( 81 %) centers and 56 ( 96.6 %) utilized an open venous system and hard-shell venous reservoir ( Table 2 ). Most centers reported utilizing arterial and cardioplegia line pressures ( 100 %, n = 58 ), level detectors , and arterial and venous blood temperature monitoring ( 100 % and 98.6 %, respectively ). Among the lowest reported safety features were one-way valves with centrifugal pumps