An oxygenator combines, in a single structure, a heat exchanger, a gas exchanger and an arterial filter. Such an oxygenator permits fewer fluid connections and thus may simplify an extracorporeal blood circuit, including a heart-lung machine and a blood reservoir, in which it is used. In some cases, the oxygenator may be configured to include multiple purge ports for purging bubbles both before and after filtering the blood.
