The precise determination of the window of implantation significantly improves ART outcomes.

The human endometrium is receptive to the embryo for a specific period of time known as the window of implantation (WOI). During this period, the endometrium shows a specific gene expression profile suitable for endometrial function evaluation. ER Map is a molecular tool able to accurately predict endometrial receptivity status by transcriptomic analysis. In this retrospective study, including 2256 subfertile patients undergoing ART treatment, the clinical value of precise WOI determination is studied in detail. Results obtained when single embryo transfers (sET) were scheduled either within the WOI timeframe as established by ER Map, or deviating from this WOI, are assessed and compared. Data obtained showed that 34.18% (771/2256) of patients had a displaced WOI. Analysis of ART outcomes showed significantly higher pregnancy rates in transfers scheduled within the WOI predicted compared to transfers that deviated more than 12h from this WOI (44.35% vs 23.08%, p < 0.001). The deviation from the WOI had also an impact on the progression of pregnancy, with a significant increase in pregnancy loss (~ twofold) observed in transfers that deviated more than 12h from the WOI predicted. These results indicate that the precise determination of the WOI and personalised embryo transfer can significantly improve clinical outcomes.

Euploid embryos selected by an automated time-lapse system have superior SET outcomes than selected solely by conventional morphology assessment.

PURPOSE: We investigated if automated TLI selection may be a valuable strategy to identify those euploid embryos with the best chances of success. METHODS: This is a unicentric and retrospective study involving 244 patients undergoing preimplantational genetic screening (PGS) cycles with autologous oocytes or oocyte donation (OD) with single euploid embryo transferred. We examined euploid embryos selected for transfer based on morphology evaluation alone (PGS-only; control group) or by assessment using an automated TLI system (Eeva™; PGS-TLI group). RESULTS: In both, autologous oocytes and OD patients, significantly better implantation and clinical and ongoing pregnancy rates were obtained in the PGS-TLI group when euploid embryos with high implantation potential as predicted by the automated TLI System (Eeva™) were transferred compared with the PGS-only group. This improvement was also observed when only transfers of good morphological quality embryos were compared. TLI categories showed significant differences on blastocyst formation and euploidy rate. CONCLUSIONS: Automated TLI combined with PGS is a useful prognostic tool to identify euploid embryos with the highest potential for implantation and pregnancy. Further, these results provide evidence that a healthy pregnancy does not only depend upon normal chromosomal status.

Development of a new comprehensive and reliable endometrial receptivity map (ER Map/ER Grade) based on RT-qPCR gene expression analysis.

STUDY QUESTION: Is it possible to determine the receptivity status of an endometrium by combined quantitative reverse transcription PCR (RT-qPCR) expression analysis of genes involved in endometrial proliferation and immunity? SUMMARY ANSWER: The new ER Map®/ER Grade® test can predict endometrial receptivity status by RT-qPCR using a new panel of genes involved in endometrial proliferation and the maternal immune response associated to embryonic implantation. WHAT IS KNOWN ALREADY: The human endometrium reaches a receptive status adequate for embryonic implantation around Days 19-21 of the menstrual cycle. During this period, known as the window of implantation (WOI), the endometrium shows a specific gene expression profile suitable for endometrial function evaluation. The number of molecular diagnostic tools currently available to characterize this process is very limited. In this study, a new system for human endometrial receptivity evaluation was optimized and presented for the first time. STUDY DESIGN, SIZE, DURATION: ER Map®/ER Grade® validation was achieved on 312 endometrial samples including fertile women and patients undergoing fertility treatment between July 2014 and March 2016. Expression analyses of 184 genes involved in endometrial receptivity and immune response were performed. Samples were additionally tested with an independent endometrial receptivity test. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 96 fertile women and 120 assisted reproduction treatment (ART) patients participated in the study. Endometrial biopsy samples were obtained at LH + 2 and LH + 7 days in fertile subjects in a natural cycle and at the window of implantation (WOI) in patients in a hormone-replacement therapy (HRT) cycle. Total RNA was purified, quality-checked and reverse-transcribed. Gene expression was quantified by high-throughput RT-qPCR and statistically analyzed. Informative genes were selected and used to classify samples into four different groups of endometrial receptivity status. MAIN RESULTS AND THE ROLE OF CHANCE: Significantly different gene expression levels were found in 85 out of 184 selected genes when comparing LH + 2 and LH + 7 samples (paired t-test, P < 0.05). Gene ontology analyses revealed that cell division and proliferation, cell signaling and response, extracellular organization and communication, immunological activity, vascular proliferation, blood pressure regulation and embryo implantation are the most over-represented biological terms in this group of genes. Principal component analysis and discriminant functional analysis showed that 40 of the differentially expressed genes allowed accurate classification of samples according to endometrial status (proliferative, pre-receptive, receptive and post-receptive) in both fertile and infertile groups. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: To evaluate the efficacy of this new tool to improve ART outcomes, further investigations such as non-selection studies and randomized controlled trials will also be required. WIDER IMPLICATIONS OF THE FINDINGS: A new comprehensive system for human endometrial receptivity evaluation based on gene expression analysis has been developed. The identification of the optimal time for embryo transfer is essential to maximize the effectiveness of ART. This study is a new step in the field of personalized medicine in human reproduction which may help in the management of endometrial preparation for embryo transfer, increasing the chances of pregnancy for many couples. STUDY FUNDING/COMPETING INTEREST(S): The authors have no potential conflict of interest to declare. No external funding was obtained for this study.

New permeable cryoprotectant-free vitrification method for native human sperm.

STUDY QUESTION: Is permeable cryoprotectant-free vitrification of native sperm samples a good alternative to conventional slow freezing? SUMMARY ANSWER: The permeable cryoprotectant-free sperm vitrification protocol tested in this study renders considerably better recovery rates of good quality sperm compared to slow freezing. WHAT IS KNOWN ALREADY: Slow freezing is currently the most commonly used technique for sperm cryopreservation, though this method has been repeatedly shown to have negative effects on both structural and functional sperm features. New alternative methods such as vitrification have been established as a successful alternative in other reproductive cell types, but vitrification of spermatozoa is still a rather unexplored methodology, with limited studies showing its efficacy in male gametes. STUDY DESIGN SIZE, DURATION: This study included 18 normozoospermic sperm samples from patients seeking ART treatment between 2014 and 2015. The effects of a new vitrification protocol on functional and structural sperm quality parameters in comparison to fresh and slow-frozen samples were assessed. PARTICIPANTS/MATERIALS, SETTING, METHODS: All samples were divided into three aliquots: fresh (F), slow freezing-thawing (S) and vitrification-warming (V). Sperm concentration, motility, morphology, vitality, DNA fragmentation, cytoskeleton integrity and spontaneous acrosome reaction were assessed and compared between the groups. MAIN RESULTS AND THE ROLE OF CHANCE: Results showed improved preservation of sperm features after vitrification compared to conventional freezing. Permeable cryoprotectant-free vitrification presented a significantly higher percentage of live spermatozoa, than slow freezing, better preservation of acrosomes was achieved in vitrified samples and DNA fragmentation was reduced approximately one-third on average compared to slow freezing. Regarding tubulin assay, three different labelling patterns were observed. The frequency of these labelling patterns was similar in F and V groups but this was not the case of the S group. The multivariate analysis of all sperm quality parameters studied revealed that the V group presented features that are closer to the F group than the S group, indicating that samples are better preserved through vitrification than slow freezing. LIMITATIONS REASONS FOR CAUTION: This validation has been undertaken only on normozoospermic sperm samples. It would be necessary to compare these results in pathological samples and also to evaluate the influence of the application of this methodology on clinical outcomes. WIDER IMPLICATIONS OF THE FINDINGS: The sperm vitrification protocol here described warrants better maintenance of sperm quality parameters than traditional freezing methods and may be a good alternative to preserve sperm samples from patients seeking IVF treatment. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by IVF-Spain Foundation. The authors have no conflicts of interest to declare.

The 'heritability' of domestication and its functional partitioning in the pig.

We propose to estimate the proportion of variance explained by regression on genome-wide markers (or genomic heritability) when wild/domestic status is considered the phenotype of interest. This approach differs from the standard Fst in that it can accommodate genetic similarity between individuals in a general form. We apply this strategy to complete genome data from 47 wild and domestic pigs from Asia and Europe. When we partitioned the total genomic variance into components associated to subsets of single nucleotide polymorphisms (SNPs) defined in terms of their annotation, we found that potentially deleterious non-synonymous mutations (9566 SNPs) explained as much genetic variance as the whole set of 25 million SNPs. This suggests that domestication may have affected protein sequence to a larger extent than regulatory or other kinds of mutations. A pathway-guided analysis revealed ovarian steroidogenesis and leptin signaling as highly relevant in domestication. The genomic regression approach proposed in this study revealed molecular processes not apparent through typical differentiation statistics. We propose that at least some of these processes are likely new discoveries because domestication is a dynamic process of genetic selection, which may not be completely characterized by a static metric like Fst. Nevertheless, and despite some particularly influential mutation types or pathways, our analyses tend to rule out a simplistic genetic basis for the domestication process: neither a single pathway nor a unique set of SNPs can explain the process as a whole.

A combined coalescence gene-dropping tool for evaluating genomic selection in complex scenarios (ms2gs).

We present ms2gs, a combined coalescence - gene dropping (i.e. backward-forward) simulator for complex traits. It therefore aims at combining the advantages of both approaches. It is primarily conceived for very short term, recent scenarios such as those that are of interest in animal and plant breeding. It is very flexible in terms of defining QTL architecture and SNP ascertainment bias, and it allows for easy modelling of alternative markers such as RADs. It can use real sequence or chip data or generate molecular polymorphisms via the coalescence. It can generate QTL conditional on extant molecular information, such as low-density genotyping. It models (simplistically) sequence, imputation or genotyping errors. It requires as input both genotypic data in plink or ms formats, and a pedigree that is used to perform the gene dropping. By default, it compares accuracy for BLUP, SNP ascertained data, sequence, and causal SNPs. It employs VanRaden's linear (GBLUP) and nonlinear method for incorporating molecular information. To illustrate the program, we present a small application in a half-sib population and a multiparental (MAGIC) cross. The program, manual and examples are available at https://github.com/mperezenciso/ms2gs.

The chimerical genome of Isla del Coco feral pigs (Costa Rica), an isolated population since 1793 but with remarkable levels of diversity.

The history of domestic species and of their wild ancestors is not a simple one, and feral processes can clarify key aspects of this history, including the adaptive processes triggered by new environments. Here, we provide a comprehensive genomic study of Isla del Coco (Costa Rica) feral pigs, a unique population that was allegedly founded by two individuals and has remained isolated since 1793. Using SNP arrays and genome sequencing, we show that Cocos pigs are hybrids between Asian and European pigs, as are modern international pig breeds. This conclusively shows that, as early as the 18th century, British vessels were loading crossbred pigs in Great Britain and transporting them overseas. We find that the Y chromosome has Asian origin, which has not been reported in any international pig breed. Chinese haplotypes seem to have been transmitted independently between Cocos and other pig breeds, suggesting independent introgression events and a complex pattern of admixing. Although data are compatible with a founder population of N = 2, variability levels are as high in Cocos pigs as in international pig breeds (~1.9 SNPs/kb) and higher than in European wild boars or local breeds (~1.7 SNPs/kb). Nevertheless, we also report a 10-Mb region with a marked decrease in variability across all samples that contains four genes (CPE, H3F3C, SC4MOL and KHL2) previously identified as highly differentiated between wild and domestic pigs. This work therefore illustrates how feral population genomic studies can help to resolve the history of domestic species and associated admixture events.

Pipeliner: software to evaluate the performance of bioinformatics pipelines for next-generation resequencing.

The choice of technology and bioinformatics approach is critical in obtaining accurate and reliable information from next-generation sequencing (NGS) experiments. An increasing number of software and methodological guidelines are being published, but deciding upon which approach and experimental design to use can depend on the particularities of the species and on the aims of the study. This leaves researchers unable to produce informed decisions on these central questions. To address these issues, we developed pipeliner - a tool to evaluate, by simulation, the performance of NGS pipelines in resequencing studies. Pipeliner provides a graphical interface allowing the users to write and test their own bioinformatics pipelines with publicly available or custom software. It computes a number of statistics summarizing the performance in SNP calling, including the recovery, sensitivity and false discovery rate for heterozygous and homozygous SNP genotypes. Pipeliner can be used to answer many practical questions, for example, for a limited amount of NGS effort, how many more reliable SNPs can be detected by doubling coverage and halving sample size or what is the false discovery rate provided by different SNP calling algorithms and options. Pipeliner thus allows researchers to carefully plan their study's sampling design and compare the suitability of alternative bioinformatics approaches for their specific study systems. Pipeliner is written in C++ and is freely available from http://github.com/brunonevado/Pipeliner.

Genome data from a sixteenth century pig illuminate modern breed relationships.

Ancient DNA (aDNA) provides direct evidence of historical events that have modeled the genome of modern individuals. In livestock, resolving the differences between the effects of initial domestication and of subsequent modern breeding is not straight forward without aDNA data. Here, we have obtained shotgun genome sequence data from a sixteenth century pig from Northeastern Spain (Montsoriu castle), the ancient pig was obtained from an extremely well-preserved and diverse assemblage. In addition, we provide the sequence of three new modern genomes from an Iberian pig, Spanish wild boar and a Guatemalan Creole pig. Comparison with both mitochondrial and autosomal genome data shows that the ancient pig is closely related to extant Iberian pigs and to European wild boar. Although the ancient sample was clearly domestic, admixture with wild boar also occurred, according to the D-statistics. The close relationship between Iberian, European wild boar and the ancient pig confirms that Asian introgression in modern Iberian pigs has not existed or has been negligible. In contrast, the Guatemalan Creole pig clusters apart from the Iberian pig genome, likely due to introgression from international breeds.

Resequencing studies of nonmodel organisms using closely related reference genomes: optimal experimental designs and bioinformatics approaches for population genomics.

Decreasing costs of next-generation sequencing (NGS) experiments have made a wide range of genomic questions open for study with nonmodel organisms. However, experimental designs and analysis of NGS data from less well-known species are challenging because of the lack of genomic resources. In this work, we investigate the performance of alternative experimental designs and bioinformatics approaches in estimating variability and neutrality tests based on the site-frequency-spectrum (SFS) from individual resequencing data. We pay particular attention to challenges faced in the study of nonmodel organisms, in particular the absence of a species-specific reference genome, although phylogenetically close genomes are assumed to be available. We compare the performance of three alternative bioinformatics approaches ­ genotype calling, genotype­haplotype calling and direct estimation without calling genotypes. We find that relying on genotype calls provides biased estimates of population genetic statistics at low to moderate read depth (2­8X). Genotype­haplotype calling returns more accurate estimates irrespective of the divergence to the reference genome, but requires moderate depth (8­20X). Direct estimation without calling genotypes returns the most accurate estimates of variability and of most SFS tests investigated, including at low read depth (2­4X). Studies without species-specific reference genome should thus aim for low read depth and avoid genotype calling whenever individual genotypes are not essential. Otherwise, aiming for moderate to high depth at the expense of number of individuals, and using genotype­haplotype calling, is recommended.

Genomic relationships computed from either next-generation sequence or array SNP data.

The use of sequence data in genomic prediction models is a topic of high interest, given the decreasing prices of current 'next'-generation sequencing technologies (NGS) and the theoretical possibility of directly interrogating the genomes for all causal mutations. Here, we compare by simulation how well genetic relationships (G) could be estimated using either NGS or ascertained SNP arrays. DNA sequences were simulated using the coalescence according to two scenarios: a 'cattle' scenario that consisted of a bottleneck followed by a split in two breeds without migration, and a 'pig' model where Chinese introgression into international pig breeds was simulated. We found that introgression results in a large amount of variability across the genome and between individuals, both in differentiation and in diversity. In general, NGS data allowed the most accurate estimates of G, provided enough sequencing depth was available, because shallow NGS (4×) may result in highly distorted estimates of G elements, especially if not standardized by allele frequency. However, high-density genotyping can also result in accurate estimates of G. Given that genotyping is much less noisy than NGS data, it is suggested that specific high-density arrays (~3M SNPs) that minimize the effects of ascertainment could be developed in the population of interest by sequencing the most influential animals and rely on those arrays for implementing genomic selection.

Increased numbers of DNA-damaged spermatozoa in samples presenting an elevated rate of numerical chromosome abnormalities.

STUDY QUESTION: Is there a relationship between DNA damage and numerical chromosome abnormalities in the sperm of infertile patients? SUMMARY ANSWER: A strong link between DNA fragmentation and the presence of numerical chromosome abnormalities was detected in human sperm. Chromosomally abnormal spermatozoa were more likely to be affected by DNA fragmentation than those that were chromosomally normal. WHAT IS KNOWN ALREADY: Several studies have described the presence of elevated levels of DNA damage or chromosome defects in the sperm of infertile or subfertile men. However, the nature of the relationship between sperm DNA damage and chromosome abnormalities is poorly understood. The fact that some assisted reproductive techniques have the potential to allow abnormal spermatozoa to achieve oocyte fertilization has led to concerns that pregnancies achieved using such methods may be at elevated risk of genetic anomalies. STUDY DESIGN, SIZE, DURATION: For this prospective study, semen samples were collected from 45 infertile men. PARTICIPANTS, SETTING, METHODS: Samples were assessed for DNA fragmentation using the Sperm Chromatin Dispersion Test (SCDt) and for chromosome abnormalities using multi-colour fluorescence in situ hybridization (FISH) with probes specific to chromosomes 13, 16, 18, 21, 22, X and Y. Additionally, both parameters were assessed simultaneously in 10 of the samples using a protocol combining SCDt and FISH. MAIN RESULTS AND THE ROLE OF CHANCE: A significant correlation between the proportion of sperm with a numerical chromosome abnormality and the level of DNA fragmentation was observed (P < 0.05). Data from individual spermatozoa subjected to combined chromosome and DNA fragmentation analysis indicated that chromosomally abnormal sperm cells were more likely to display DNA damage than those that were normal for the chromosomes tested (P < 0.05). Not only was this association detected in samples with elevated levels of numerical chromosome abnormalities, but it was also evident in samples with chromosome abnormality rates in the normal range. LIMITATIONS, REASONS FOR CAUTION: The inability to assess the entire chromosome complement is the main limitation of all studies aimed at assessing numerical chromosome abnormalities in sperm samples. As a result, some of the sperm classified as 'chromosomally normal' may be aneuploid for chromosomes that were not tested. WIDER IMPLICATIONS OF THE FINDINGS: During spermatogenesis, apoptosis (a process that involves active DNA degradation) acts to eliminate abnormal sperm. Failure to complete apoptosis may explain the coincident detection of aneuploidy and DNA fragmentation in some spermatozoa. In addition to shedding light on the biological mechanisms involved in the processing of defective sperm, this finding may also be of clinical relevance for the identification of patients at increased risk of miscarriage or chromosomally abnormal pregnancy. In some instances, detection of elevated sperm DNA fragmentation may indicate the presence of chromosomal abnormalities. It may be worth considering preimplantation genetic screening (PGS) of embryos produced using such samples in order to minimize the risk of aneuploidy.

Worldwide genetic relationships of pigs as inferred from X chromosome SNPs.

The phylogeography of the porcine X chromosome has not been studied despite the unique characteristics of this chromosome. Here, we genotyped 59 single nucleotide polymorphisms (SNPs) in 312 pigs from around the world, representing 39 domestic breeds and wild boars in 30 countries. Overall, widespread commercial breeds showed the highest heterozygosity values, followed by African and American populations. Structuring, as inferred from FST and analysis of molecular variance, was consistently larger in the non-pseudoautosomal (NPAR) than in the pseudoautosomal regions (PAR). Our results show that genetic relationships between populations can vary widely between the NPAR and the PAR, underscoring the fact that their genetic trajectories can be quite different. NPAR showed an increased commercial-like genetic component relative to the PAR, probably because human selection processes to obtain individuals with high productive parameters were mediated by introgressing boars rather than sows.

Porcine colonization of the Americas: a 60k SNP story.

The pig, Sus scrofa, is a foreign species to the American continent. Although pigs originally introduced in the Americas should be related to those from the Iberian Peninsula and Canary islands, the phylogeny of current creole pigs that now populate the continent is likely to be very complex. Because of the extreme climates that America harbors, these populations also provide a unique example of a fast evolutionary phenomenon of adaptation. Here, we provide a genome wide study of these issues by genotyping, with a 60k SNP chip, 206 village pigs sampled across 14 countries and 183 pigs from outgroup breeds that are potential founders of the American populations, including wild boar, Iberian, international and Chinese breeds. Results show that American village pigs are primarily of European ancestry, although the observed genetic landscape is that of a complex conglomerate. There was no correlation between genetic and geographical distances, neither continent wide nor when analyzing specific areas. Most populations showed a clear admixed structure where the Iberian pig was not necessarily the main component, illustrating how international breeds, but also Chinese pigs, have contributed to extant genetic composition of American village pigs. We also observe that many genes related to the cardiovascular system show an increased differentiation between altiplano and genetically related pigs living near sea level.

Genome-wide association study for intramuscular fatty acid composition in an Iberian × Landrace cross.

The lipid content and fatty acid (FA) profile have an important impact in human health as well as in the technological transformation and nutritional and organoleptic quality of meat. A genome-wide association study (GWAS) on 144 backcross pigs (25% Iberian × 75% Landrace) was performed for 32 traits associated with intramuscular FA composition and indices of FA metabolism. The GWAS was carried out using Qxpak 5.0 and the genotyping information obtained from the Porcine SNP60K BeadChip (Illumina Inc., San Diego, CA). Signals of significant association considering a false- discovery rate (q-value < 0.05) were observed in 15 of the 32 analyzed traits, and a total of 813 trait-associated SNP (TAS), distributed in 43 chromosomal intervals on almost all autosomes, were annotated. According to the clustering analysis based on functional classification, several of the annotated genes are related to FA composition and lipid metabolism. Some interesting positional concordances among TAS and previously reported QTL for FA compositions and/or other lipid traits were also found. These common genomic regions for different traits suggest pleiotropic effects for FA composition and were found primarily on SSC4, SSC8, and SSC16. These results contribute to our understanding of the complex genetic basis of FA composition and FA metabolism.

Development of a novel synthetic oligopeptide for the detection of DNA damage in human spermatozoa.

BACKGROUND: The integrity of DNA in spermatozoa is considered an additional parameter of semen quality and a potential fertility predictor. Significant progress has been made in recent years towards the development of reliable tests for sperm chromatin integrity and DNA damage assessment. However, most of the techniques available are labor intensive, require expensive instrumentation or utilize enzymes whose activity could be compromised by the highly condensed nature of sperm chromatin. In addition, all the methods currently available involve the destruction of the sperm tested; none is able to select intact spermatozoa that could then be used for fertilization. The aim of the present study was to create a peptide ligand-based stain, capable of binding specific DNA structures, thereby revealing the presence of DNA damage, preferably in living cells. METHODS: The peptide was bioinformatically modelled on the critical region of the p53 protein associated with DNA binding and fluorescently labeled with a terminal rhodamine B dye. The ability of this 21 amino acid synthetic peptide (DW1) to detect DNA damage in intact and fixed human spermatozoa was assessed in detail. Human sperm samples (n=20) were treated with reagents that induce single- and/or double-stranded DNA breaks. The effect of these treatments on peptide-labelling was measured and compared with results obtained using established tests for the evaluation of DNA damage, such as comet assay, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and sperm chromatin dispersion test. RESULTS: The peptide had a high affinity for single-stranded DNA, and DNA lesions such as double- and single-stranded breaks. The proportion of spermatozoa with intense staining was found to be closely associated with the percentage of cells possessing DNA damage. The analysis of 10 sperm samples using DW1 staining and TUNEL technique showed a significant correlation between the extent of DNA fragmentation for the two methods (r=0.892, Pearson's correlation, P<0.05). CONCLUSIONS: We have produced a novel peptide-based stain capable of detecting DNA damage in individual sperm cells. Evaluation of sperm DNA fragmentation using this peptide may be an inexpensive and easier to use alternative to the tests in current use. Additionally, although DW1 currently requires removal of the membrane using a detergent, further research may allow this approach to be applied to the selection of viable spermatozoa with intact DNA for use in ICSI and/or intra-cytoplasmic morphologically selected sperm injection.

[Assessment of learning in blind orotracheal intubation with Fastrach masks using a cumulative sum curves (CuSum) in the SimMan Universal Simulator]. / Evaluación del aprendizaje de intubación orotraqueal a ciegas a través de mascarillas Fastrach mediante curvas de sumas acumulativas (CuSum) en el Simulador Universal SimMan.

OBJECTIVE: To assess training in blind intubation with the Fastrach laryngeal mask in a simulation model by applying the cumulative sums (CuSum) method. MATERIAL AND METHODS: Six anaesthesiology resident doctors, with no previous experience of the technique, participated, three in their first year, and three in the second. The study was conducted with the help of the SimMan Universal Simulator. Fifty attempts by each one of them over a four month period, divided into two stages: the first 20 with minimum airway difficulty, and the next 30 with limitations of flexion-extension movements to <80°. An unacceptable failure rate was set at 10% after a second failed attempt. The time limit set to be considered a success was 60seconds. RESULTS: A total of 120 attempts in the first stages, and the remaining 180 in the second were analysed individually, all managing to achieve acceptable success rates of 90%: 84% in the first attempt and 13.33% in the second. A total of 2.66% failures were recorded. The learning curve showed that the residents began to achieve an acceptable 90% success rate in case number 25±11.76 of the 50 attempts. CONCLUSIONS: This statistical method and the SimMan simulator, used together, have demonstrated to be very useful tools in assessing learning curves in this technique.

Evaluación del aprendizaje de intubación orotraqueal a ciegas a través de mascarillas Fastrach mediante curvas de sumas acumulativas (CuSum) en el Simulador Universal SimMan / Assessment of learning in blind orotracheal intubation with Fastrach masks using a cumulative sum curves (CuSum) in the SimMan Universal Simulator

Objetivos: Evaluar el aprendizaje de intubación a ciegas a través de mascarilla laríngea Fastrach en un modelo de simulación, mediante la aplicación del método de sumas acumulativas CuSum. Material y métodos: Participaron seis médicos residentes de Anestesiología, tres en su primer año y tres en el segundo, sin experiencia previa en la técnica. El estudio se realizó con la ayuda del Simulador Universal SimMan. A lo largo de 4 meses, se registraron 50 intentos en cada uno de ellos, divididos en dos etapas: los primeros 20 con mínima dificultad de vía aérea y los siguientes 30 con limitación a los movimientos de flexoextensión a < 80°. Se aceptó como índice inaceptable de fallo el 10% tras un segundo intento fallido. El límite temporal fijado para considerarlo éxito fue de 60 s. Resultados: Se analizaron 120 intentos en la primera etapa y los 180 restantes en la segunda, individualmente; todos lograron unos índices aceptables de éxito del 90%: el 84% en el primer intento y el 13,33% en el segundo. Se registró un 2,66% de fallos del total. La curva de aprendizaje mostró que los residentes lograron alcanzar el índice aceptable de éxito del 90% como media en el caso número 25 ± 11,76, de 50 casos. Conclusiones: Se ha demostrado que este método estadístico y el simulador SimMan utilizados conjuntamente son unas herramientas muy útiles en la evaluación del aprendizaje de esta técnica(AU)

Objective: To assess training in blind intubation with the Fastrach laryngeal mask in a simulation model by applying the cumulative sums (CuSum) method. Material and methods: Six anaesthesiology resident doctors, with no previous experience of the technique, participated, three in their first year, and three in the second. The study was conducted with the help of the SimMan Universal Simulator. Fifty attempts by each one of them over a four month period, divided into two stages: the first 20 with minimum airway difficulty, and the next 30 with limitations of flexion-extension movements to <80°. An unacceptable failure rate was set at 10% after a second failed attempt. The time limit set to be considered a success was 60 seconds. Results: A total of 120 attempts in the first stages, and the remaining 180 in the second were analysed individually, all managing to achieve acceptable success rates of 90%: 84% in the first attempt and 13.33% in the second. A total of 2.66% failures were recorded. The learning curve showed that the residents began to achieve an acceptable 90% success rate in case number 25±11.76 of the 50 attempts. Conclusions: This statistical method and the SimMan simulator, used together, have demonstrated to be very useful tools in assessing learning curves in this technique(AU)