Page 33 - ANZCP Gazette November 2021

Steel and Bui
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25 20 15 10
5 0
23
15
13
8
4
<=100 cases
101-250 cases
251-400 cases
401-550 cases
> 551 cases
Figure 1. Annual caseload across Australian units.
region. This information will also provide direction for future research into priming practices with a view to improve patient outcomes.
Method
Following local ethical (Western Sydney Local Health District Human Research Ethics committee, approval #LNR/17/WMEAD/439/5361) and governance approval, a survey of 15 questions covering various aspects of priming constituents was sent via email to all 63 adult open-heart centres across Australia.
The survey was in the form of a free Google Docs Survey (Google LLC, Mountain View, CA, USA) accessed online through a link sent within the invitation email. One respondent per unit was selected to com- plete the survey and only one response per unit was accepted. Respondents were contacted by a phone call to their unit to obtain their email addresses.
Results were collected directly by Google Docs into a spreadsheet and the data deidentified here. Microsoft Excel 2013 (Microsoft Corp., Redmond, WA, USA) was used to analyse the data.
The survey was open for 5 months from Dec 2017. A follow-up email was sent after 6 weeks to prompt com- pletion as required. Respondents were able to opt out of this survey by declining to provide their email address upon the initial phone call or by declining to complete the online survey once it was emailed.
Respondents were asked two demographic questions on their unit, namely, the public or private nature of their unit and their annual caseload. Demographic data was used to group like centres for analysis purposes only. The data on each unit’s caseload was also used to assess the nationwide extent of the various prime inter- ventions.
The nature of their base priming solution was sur- veyed, as was any additional constituents, together with their dosage and the rationale for adding these. Some questions had multiple-choice-style answers with a free text option, while others were open-ended questions. This allowed the respondents to provide more than one reason or add comments with their answers. Respondents were also asked if there were additives they
would like to add or no longer add to their prime and the reason why. Priming volume was not included within the scope of this survey.
Additional questions were asked to determine if the respondent varied their priming constituents for par- ticular scenarios, for instance, for diabetic patients or deep hypothermic circulatory arrest (DHCA) cases. Who determined the prime constituents was also sur- veyed.
Results
All 63 adult open-heart centres replied to our online survey, giving us a 100% response rate. Australia has 25 public units which conduct 12,365 cases annually. These public units represent 40% of the total open-heart cen- tres conducting 57% of the annual total of open-heart procedures within Australia. Thus, the 38 private units (60% of total units) conduct 9,385 cases (43% of the total open-heart procedures) in Australia.
One-third of the units perform between 100 and 250 cases annually and one-third perform over 400 cases per year (Figure 1).
Hartmann’s and Plasma-Lyte 148 (Plasma-Lyte) are the main base solutions used for priming across Australian adult units. Figure 2 details the types of prime base solutions used, together with the count and percentage of units that use it and the annual Australian caseload for that solution.
It is interesting to note that three units currently using Hartmann’s solution as a prime base commented in their survey responses that they were in the process of transitioning to Plasma-Lyte (representing another 1,350 patients annually).
The most common rationale for the choice of base crystalloid solution was historic precedent (20 responses). All respondents’ rationales are shown in Figure 3. Figure 4 lists the composition of the two crys- talloid solutions for comparison.
The use of prime base solutions was similar between public and private practice within adult Australian units. And 58% of private units used Hartmann’s as a prime base as did 42% of public units.
All adult Australian centres routinely add heparin to their prime solutions for anticoagulation. The dose of heparin ranges from 5,000 to 20,000 IU. Most units (43 units; 68%) add 10,000 IU heparin to their prime solu- tion, with five units adding 5,000 IU and nine units add- ing 15,000IU of heparin. The remaining units add a variety of doses within the above range.
Heparin is the only additive to the prime base solu- tion for 12 adult Australian units (performing 4,850 cases annually). Five of these were Hartmann’s units (1,860 patients per year) and seven were Plasma-Lyte units (2,990 patients per year). Another four units (1,670
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Number of units