Problems with the airway can become fatal within minutes, so recognizing and relieving obstruction is one of the most important first aid skills. The signs of an obstructed airway include sudden inability to speak, cough, or breathe; the person clutching at their throat; blue lips or skin; and high-pitched breathing sounds. For a conscious choking adult, the Heimlich maneuver is performed by standing behind the person, placing a fist just above the navel and below the ribcage, grasping it with the other hand, and delivering quick upward thrusts until the object is expelled or the casualty becomes unresponsive.
Cardiopulmonary Resuscitation, or CPR, is a lifesaving technique that combines chest compressions with rescue breaths to restore blood circulation and oxygenation. It is performed on adults who are unresponsive, not breathing normally, and have no pulse. The correct technique requires compressing the chest at least \(5{-}6\) cm (about \(2{-}2.4\) inches) deep at a rate of \(100{-}120\) compressions per minute, allowing the chest to recoil fully between compressions. When an automated external defibrillator (AED) is available, it should be used promptly: turn the device on, follow the voice prompts, attach the pads to the bare chest, ensure no one touches the casualty during analysis, and deliver a shock if advised before resuming CPR.
Bleeding and shock are equally urgent circulation emergencies. Severe bleeding is recognized by bright red blood spurting or flowing heavily from a wound, dressings soaking through quickly, pale skin, a rapid pulse, or signs of shock. To control it, apply firm direct pressure with a sterile dressing or clean cloth, elevate the limb if possible, and reserve a tourniquet as a last resort for life-threatening limb bleeding while noting the time it was applied. Shock itself is a life-threatening condition in which vital organs receive inadequate blood flow; its signs include pale, cold, clammy skin; a rapid weak pulse; nausea; restlessness; and rapid shallow breathing. A casualty in shock should be laid down with the legs elevated about \(30\) cm (unless a spinal injury is suspected), kept warm, reassured, and given nothing to eat or drink, with breathing and pulse monitored continuously.