Summary
Extracorporeal life support (ECLS) is one of the recent fields in cardiac surgery which has improved significantly the quality of patient care in acute or chronic end-stage heart disease. The ...safe use of this new technology requires many different prerequisites which are summarized in this position article. It includes the necessary personnel and their qualifications, the structural assumptions, the required equipment, and the parameters which have to be monitored for the safe usage of these devices. In addition, indications and contraindications for ECLS, the management and control of a wide range of parameters related to the extracorporeal circulation, as well as the necessary equipment are described. Quality assurance and education are also described in this position article.
Background:
Performing cardiopulmonary bypass is a complex task which involves evaluating visual input from patient monitors and technical parameters displayed at the heart-lung machine console as ...well as reacting to other sensory input. Only few studies are available concerning the competency requirements for clinical cardiovascular perfusionists, including attention, perception, and coping with mental stress. This study aims at evaluating attention, perception, and stress levels of clinical cardiovascular perfusionists during cardiopulmonary bypass.
Methods:
Nine clinical cardiovascular perfusionists voluntarily offered to participate in the study. Participants were asked to wear Tobii 2 eye-tracking glasses throughout the procedures. Specific time points were analyzed (cardiopulmonary bypass on, initial cardioplegia delivery, steady state, cross-clamp off, and weaning from cardiopulmonary bypass). Data acquisition was supplemented by participants’ self-evaluation regarding their stress levels and by National Aeronautics and Space Administration Task Load Index (NASA TLX) questionnaires.
Results:
Seven datasets were sufficient to be evaluated. The clinical cardiovascular perfusionists’ professional experience ranged from 0.5 to 24 years. Evaluation of eye-tracking data revealed large variations in areas of interest hits, fixation, and dwell times. Across all phases, the venous reservoir, mean arterial pressure, arterial pump display, cardioplegia control, and data management system received the highest levels of attention. Pupil diameter measurements increased at start of cardiopulmonary bypass, cardioplegia delivery, and weaning off, but returned to base level during steady state. Clinical cardiovascular perfusionists’ self-evaluation showed that subjective stress level was highest at the start and the end of the procedure. NASA TLX questionnaires revealed medium-to-high mental and temporal workloads, but low physical workloads. Performance, effort, and frustration indices showed medium workloads.
Conclusion:
During cardiopulmonary bypass, perfusionists are subjected to stress. Peak stress levels were highest during start and end of cardiopulmonary bypass. Furthermore, visual attention and perception varied between the operative phases. Further studies are indicated to evaluate the design of heart-lung machines and stress-coping strategies during cardiopulmonary bypass.
Different mechanical circulatory support (MCS) systems are used in children with intractable heart failure. However, the need for anticoagulation leads to hemorrhage with subsequent use of blood ...products. We compared the coagulation disorders and the need for blood products in children treated either with extracorporeal membrane oxygenation (ECMO) or with the Berlin Heart pulsatile pneumatic ventricular assist device.
We retrospectively reviewed the first 8-day course of 64 children who were on MCS for more than 2 days between 1990 and 2002. Thirty children (median age 7.4 years, weight 25.5 kg) received Berlin Heart support and 34 children (median age 1.8 years, weight 9.2 kg) ECMO. Anticoagulation was accomplished by continuous infusion of heparin. Red blood cell count, platelet count, aPTT, AT III, fibrinogen, and ACT were measured regularly. Depending on blood loss and the coagulation disorder, red blood cells, fresh frozen plasma, platelets, and AT III were substituted.
There were no preoperative differences in hematological parameters between the two groups. In the Berlin Heart group platelet transfusion was 4.3 ml x kg x day vs 24.6 ml x kg x day in the ECMO group. Red blood cell substitution was 17.2 vs 60.3 ml.kg.day. Fresh frozen plasma substitution was 8.5 ml x kg x day vs 46.9 ml x kg x day (P<0.001). Even in the congenital heart defect subgroups, when MCS was implanted without recent cardiotomy, the differences were significant. Nevertheless, the mean daily values for hemoglobin, platelets, and fibrinogen were lower in the ECMO group. There was lower overall mortality in the Berlin Heart group.
Compared to ECMO, use of the Berlin Heart in children results in less blood loss and lower consumption of red blood cells, platelets, and fresh frozen plasma.
Objectives:
The AngioVac system (AngioDynamics, Latham, NY, USA) provides a method for the minimally invasive, percutaneous aspiration of thrombus formations originating from the central venous ...system as well as solid matter such as lead vegetations and right atrial thrombi.
Methods:
This retrospective, observational study describes the initial experience in 52 adult patients with the AngioVac system, focusing mainly on the development of the extracorporeal circuit to improve usability and safety.
Results:
The mean patient age was 62.9 years (range 23-86 years). 22 patients were female and 30 were male. Indications for percutaneous aspiration were lead vegetations (n = 36; 69.2%), right atrial thrombi (n = 9; 17.3%), central venous thrombi (n = 5; 9.6%) and pulmonary embolisms (n = 2; 3.8%). Successful aspiration was performed in 44 cases (84.6%) and partial success was achieved in five patients (9.6%), while failure to remove thrombi or vegetations occurred in three cases (5.8%). Our practical experience led to the installation of a shunt line for recirculation and the implementation of safety features concerning air handling, which are also employed in minimally invasive extracorporeal bypass circuits. Initial tests monitored the level of negative pressure according to differences in flow and access sites but these still have to be validated on a larger scale.
Conclusion:
In this initial experience, the AngioVac system appeared to be safe regarding the extracorporeal circulation and the elimination of thrombi and lead vegetations.
Background:
With the aim of integrating simulation training into the training of perfusionists, we examined whether the participants were able to transfer a specific learning content to the same and ...different situations and assessed their feedback on the simulation training. Eye-tracking was tested as a measure and supplemented by additional measures.
Methods:
A 2 × 2 mixed design was used, with test time (pre- and post-test) and training group (same and different content training) as factors. In the pre- and post-test, the participant had to handle a critical situation on the cardiopulmonary bypass, namely, a drop in arterial partial oxygen pressure. Between the two test times, the participant practised under guidance the handling of either the same critical situation (Group 1) or a different one, that is, impaired venous return (Group 2). Dependent measures were fixations of the eyes on specific areas of interest on the heart-lung machine, measures of latency and subjective assessments. Moreover, participants gave feedback on the simulation training.
Results:
Fixation analyses showed that the training led to an increased gaze on areas of interest relevant to the drop in arterial partial oxygen pressure in both groups, with a significant increase only for Group 1. The surveys revealed a great interest in the integration of simulation training into education.
Conclusion:
In combination with other measures, eye-tracking is suitable for the evaluation of simulation training. Due to the positive training effects and positive participant feedback, the integration of simulation into the training of perfusionists is advocated. Concerning transfer of learning content, more research is needed.
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