Anales de la RANM

206 A N A L E S R A N M R E V I S T A F U N D A D A E N 1 8 7 9 SIMULATED PERIPHERAL VEIN CATHETERIZATION SKILL Guasch E, et al. An RANM. 2024;141(03): 201 - 208 DISCUSSION The placental model has proven to be at least as useful for learning PVC as mannequins, considered as a current reference model in 6 th year medical students. Furthermore, the number of attempts required to reach channeling proficiency was similar comparing both models. Numerous simulation studies use mannequins for learning venous cannulation in nursing (8) and medical (9) students. There are also publica- tions on the use of cadavers (10) and other simpler venipuncture devices (11). This is the first descrip- tion that an attempt has been investigated to validate a human placenta model for learning this technique, as suggested by our group recently (2). The fact that the activity under study (PVC), can be performed and quantified in the placenta, determines its content validity as a simulation model. In addition, the similarity of results in the placenta and the reference model (mannequin) determines their concurrency validity, as it is compared to “gold standard”. These concepts were defined by McDougall in 2007 (12) on validation criteria for surgical simulators and have served as a reference for other authors (13). It is not only interesting to know that the placenta model contributes to learning, but also to what extent it may serve as a preparation for students to face the live PVC in their future patients. The usefulness of the CUSUM curves is based on setting the level of learning from which it is considered that the student masters the technique sufficiently to reproduce it safely in the current clinical practice. The use of these curves in Medicine is common to assess the progress of residents and students acquiring a skill in procedures of some technical difficulty, such as orotracheal intubation (14) or epidural anesthesia (5, 15), among other skills. There are publications of studies similar to the present one, in which the puncture was tested in patients (16) or in mannequins (8), and with ten cannulations success rates of 67-77% were achieved. In our study, ten punctures were enough for at least eight students in each of the models tested to master the technique. This fact, raises the need to individualize the number of punctures in students who require more attempts, since the percentage of successes set to acquire the competence (80%) could be very strict. This conclusion is reached by other studies that have used the CUSUM method to assess the learning of medical residents (14, 15, 17). Simulation is essential nowadays in our educational system, to teach the basics of clinical procedures and skills in the development of a safe environ- ment for students. These fictional activities provide strategies to face real situations with greater skill, confidence, and adaptability (8, 18). The benefits for the student depend to a large extent on how Figure 4. CUSUM curves in pla- centa (A) and mannequin (B). Footnote 4: X axis: number of channels (0-10). Y axis: CUSUM value. E1: student 1; E2: student 2; E3: student 3; E4: student 4; E5: student 5; E6: student 6; E7: student 7; E8: student 8; E9: stu- dent 9; E10: student 10. In graph A, all the curves cross the lower limit after 5 (range 4-8) trials, except E1 and E9. In graph B, all the curves cross the lower limit after 6 (range 5-9) trials, except E1 and E10.