The goal of this observational study is to learn about hemodynamic and respiratory repercussions during general anesthesia in patients with achalasia or gastroparesis who underwent an endoscopic treatment such as a peroral endoscopic myotomy (POEM) or gastric (GPOEM). The main questions it aims to answer are: * Are there predictable elements reliable to this study-population for the occurrence of adverse events/complications? * Is there a correlation between the value (percutaneous puncture) of the intra-abdominal pressure and the variations of the patient's respiratory and hemodynamic parameters in the event of a pneumoperitoneum complication? Participants will be treated with the usual standard of care for this procedure and no additional or specific therapy will be planned for this study.