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during CPB procedures. This sample size of this survey was primarily determined based on a two-week time frame. The survey collected data from 66 Perfusionists using an online platform targeting perfusionists across Pakistan.
Ethical considerations were upheld to ensure participant anonymity and voluntary participation. The survey consisted of multiple-choice and open-ended questions, allowing for the collection of both quantitative and qualitative data.
With an estimated total of 350 practicing perfusionists in Pakistan, the survey achieved a response rate of approximately 18.9 %, representing a significant portion of the perfusion community. Conducted via an online platform, the survey targeted participants nationwide. While specific regional data was not collected due to the anonymous nature of the survey, efforts were made to encourage participation from diverse regions across the country.
To ensure the survey was reliable and valid, several important steps were taken before distribution. The questionnaire was reviewed by a panel of experts in perfusion and cardiopulmonary bypass practices to confirm that the questions accurately represented the intended topics and were relevant to the study’ s goals. A pilot test was then conducted with a small group of perfusionists to check for clarity and relevance. Based on their feedback, the questionnaire was refined to improve its quality. Additionally, initial responses during data collection were monitored to ensure the survey remained aligned with the study’ s objectives. These steps helped ensure that the survey was welldesigned and capable of gathering reliable and meaningful data.
Ethical considerations
In conducting this survey, ethical considerations were paramount. Anonymity and confidentiality were upheld, with no personally identifiable information collected or disclosed. Participation was voluntary, ensuring no coercion. Data collected was used solely for research purposes, maintaining privacy.
Results
The Survey report“ Perfusion Practices and Safety Standards in Pakistan: Insights from a Preliminary Nationwide Survey” was conducted over a period of two weeks, yielding a total of 66 responses.
The survey consisted of five structured questions focusing on adherence to safety standards, with most responses being( Yes / No) or conditional. While this format ensured clarity in data collection, it did not include demographic information such as age, gender, or experience, which could offer additional insights. Future studies should incorporate demographic variables to provide a more comprehensive understanding of factors influencing safety practices.
The survey results were analyzed using descriptive statistics, with Yes / No responses reported as percentages and continuous variables expressed as mean values to ensure clarity and consistency. The distribution of responses for each question is visually represented in the accompanying pie charts, offering a clear snapshot of participants’ choices and opinions on the minimum standards of perfusion quality and safety in Pakistan from a professional perspective( Figs. 1 – 5, Tables 1 and 2).
Discussion
Safety features are paramount in providing good outcomes in CPB. They help prevent and manage problems that can occur during surgery. The heart lung machine is configured to sound an alarm and stop the arterial pump in the event of a high pressure, if there is too little volume in the venous reservoir, and when a bubble is detected. This prevents entry of an air embolus into the patient which can cause stroke and severe multiple organ dysfunctions. Saturation monitoring alarms are also often present in the heart lung machine are also seen as essential monitoring for the efficacy of the perfusion to the organs. Collectively these alarms can help improve perfusion of the patient, overall safety of the procedure, and ultimately better outcomes in the patient.
One of the main reasons a bubble alarm is used is to prevent gross air entrainment into the patient such as from emptying the reservoir, this is a catastrophic event where vast amounts of air is pumped into the arterial side of the patient, and can eventually lead to death. Gaseous microemboli( GME) may also arise from a number of sources during cardiac surgery such as manipulation of the aorta, cannulation, cross clamping, entrainment of air into the CPB venous line, during drug injection into the sampling manifold or from emptying the reservoir. Gaseous air is associated with covert cerebral insults, stroke and cognitive decline which has been seen in patients exposed with > 500 GME than those exposed to less [ 1 ]. A survey by Kelting T surveyed 559 certified perfusionists looking at placement of the bubble alarm and their reasons [ 2 ]. Most people( 35.6 %) placed it on the outlet of the venous reservoir as this is felt to be the most likely source of gross air if the level alarm fails. 3.8 % placed it between the arterial pump and oxygenator. 35.1 % placed it between the oxygenator and arterial line filter and 23.6 % distal to arterial filter. The reasoning being that both oxygenator and arterial filter are potential sources of where smaller bubbles may get caught and then passed on from. Specifically, placement distal to the arterial filter was seen as the protecting from all possible entry points of air. Nowadays integrated filters are common so a more recent study may show increased numbers of placement distal to the oxygenator as this will now be the most distal part of the circuit. The survey highlights many potential areas where a bubble alarm may be useful [ 3 ]. However, a study by Newlands et al comparing air bubble detectors from a Stockert S5 and S3 heart lung machine and an Emboli detection and classification quantifier found weak correlations between the two, suggesting the heart lung machine bubble detectors are not as clinically relevant when it comes to GME, but this does not negate its value for gross air detection. 27.3 % of survey respondents of our survey stated they do not use bubble detectors in their unit. Although more recent studies may help our understanding in their use for GME, potentially perfusionists not using a bubble alarm may be exposing themselves to unrecognised emboli and certainly gross air [ 1 ].
Level detectors are essential for preventing air entrainment and maintaining proper fluid balance in the circuit. A catastrophic event may occur if the reservoir empties. The level alarm is the first alert the Perfusionist will receive in this event and can be seen as a major emergency if the issue goes