"Active core rewarming" refers to

(D) All of the above # REWARMING STRATEGIES> There are numerous widely available active core rewarming options.> Airway rewarming with heated humidified oxygen (4degC to 45degC) is a convenient option via mask or endotracheal tube.> Although airway rewarming provides less heat than some other forms of active core rewarming, it eliminates respiratory heat loss and adds 1deg to 2degC to the overall rewarming rate.> Crystalloids should be heated to 40degto 42degC. The quantity of heat provided is significant only during massive volume resuscitation.> The most efficient method for heating and delivering fluid or blood is with a countercurrent in-line heat exchanger.> Heated irrigation of the gastrointestinal tract or bladder transfers minimal heat because of the limited available surface area.> These methods should be reserved for patients in cardiac arrest and then used in combination with all available active rewarming techniques.> Closed thoracic lavage is far more efficient in severely hypothermic patients with cardiac arrest.> The hemithoraces are irrigated through two large-bore thoracostomy tubes that are inserted into the left or both of the hemithoraces.> Thoracostomy tubes should not be placed in the left chest of a spontaneously perfusing patient for purposes of rewarming.> Peritoneal lavage with the dialysate at 40deg to 45degC efficiently transfers heat when delivered through two catheters with outflow suction.> Like peritoneal dialysis, standard hemodialysis is especially useful for patients with electrolyte abnormalities, rhabdomyolysis, or toxin ingestions.> The efficacy of arteriovenous anastomoses rewarming, which provides exogenous heat by immersion of the hands, forearms, feet, and calves in 44deg to 45degC water, is unclear.