Gas anesthetics are substances used to induce a state of controlled unconsciousness during surgical procedures. They are inhaled through a mask or breathing tube, allowing for quick absorption into the bloodstream. Common examples include nitrous oxide and isoflurane, which help manage pain and anxiety while ensuring the patient remains unconscious. These anesthetics work by altering brain activity, specifically affecting neurotransmitters that regulate consciousness and sensation. The dosage can be adjusted throughout the procedure to maintain the desired level of anesthesia, ensuring patient safety and comfort during operations.