The first match from that sentence seems to be from a Podemos reddit channel tittled "¿Qué pregunta para el cambio en Andalucía le harías a Teresa Rodríguez?" (trans. "What question to achieve the change in Andalusia would you make to Teresa Rodríguez?") where a commenter says on 03/10/2015 the following:
pablo iglesias hace un comentario en twitter hace 6 días. en que dice
lo siguiente : (preguntémonos si es lógico que el esfuerzo humano de
los celadores y celadoras sea menos recompensado que el de la casta
médica) Soy un médico anestesiólogo ...
Pablo Iglesias made 6 days ago a comment on twitter in which he says the following: "Lets ask ourselves if it's logical that human effort of the orderlies is paid less than that of the medical cast". I am a anesthetist medic ...
As the allegedly original source did not include link or proof, there is no way to know whether the tweet did exist and was deleted or whether that comment was fake and Pablo Iglesias is right.