title: The author responds.
authors.affiliation: Unità Operativa di Pronto Soccorso e Medicina D'urgenza, Dipartimento di Emergenza e Urgenza, Ospedale Maggiore Niguarda, Milano, Italy. Electronic address: francesca.cortellaro@gmail.com.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cortellaro
mesh_terms: D002405:Catheterization, Central Venous / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015641:Radiography, Interventional / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D018084:Ultrasonography, Interventional / Q000379:methods*