Back blows are a time-sensitive first aid technique used to clear a severe airway obstruction (choking). This action uses mechanical force to create a burst of pressure in the lungs, which helps expel the foreign object blocking the windpipe. The effectiveness of this maneuver relies heavily on correct positioning, which leverages gravity and provides necessary support to the person receiving aid.
Recognizing a Severe Airway Obstruction
The decision to administer back blows begins with recognizing the signs of a severe airway blockage. If an adult or child has a mild obstruction, they can still cough forcefully or speak, indicating some air movement. The most appropriate action is to encourage them to continue coughing, as this is the body’s most effective self-clearing mechanism.
A severe airway obstruction demands immediate intervention. The person will be unable to speak, cry, or cough effectively, and they may clutch at their throat (the universal distress signal for choking). Breathing may be noisy or absent, and the skin, lips, or nails may turn pale or blue due to lack of oxygen. Recognizing these signs means the rescuer must immediately proceed to the five-and-five approach, starting with back blows.
Positioning the Conscious Victim for Back Blows
The precise positioning of the conscious person is critical for maximizing the effectiveness of back blows. The goal is to orient the person so that gravity assists the blows in dislodging the obstruction from the airway. The rescuer should stand slightly to the side and just behind the person who is choking.
The person must be bent over significantly at the waist, positioning their upper body nearly parallel to the ground. This extreme forward lean ensures that if the object is dislodged, it will fall forward and out of the mouth, rather than slipping further down the airway. To maintain this position, the rescuer must place one arm diagonally across the person’s chest to provide firm support.
This supporting arm acts as a brace, keeping the person stable and preventing them from collapsing forward during the forceful application of the blows. For a smaller child, the rescuer may need to kneel down behind them to achieve the correct angle and body position for effective support.
Delivering Effective Back Blows and Next Steps
With the person correctly positioned and bent forward, the rescuer delivers the back blows using the heel of the free hand. This is the firm, muscular part of the palm just below the wrist. The target area is the space directly between the person’s shoulder blades.
The technique involves delivering five separate, distinct, and forceful blows in rapid succession. Each strike should be delivered with enough force to create a sudden compression of air within the lungs, which then acts as a powerful, upward cough to eject the foreign body. After the five blows are completed, the rescuer must check the person’s mouth to see if the obstruction has been cleared.
If the airway obstruction is not relieved after the initial set of five back blows, the rescuer must immediately transition to five abdominal thrusts (the Heimlich maneuver). The recommended protocol is to alternate continuously between five back blows and five abdominal thrusts until the object is expelled, the person begins to breathe normally, or they become unresponsive. If the person loses consciousness, first aid protocols shift entirely to initiating cardiopulmonary resuscitation (CPR).
Adjustments for Infants and Vulnerable Adults
Specific populations require significant modifications to the standard positioning and technique due to their size or physical condition. For an infant under one year of age, back blows are administered while the baby is placed face down along the rescuer’s forearm, which rests on the thigh. The infant’s head must be held lower than the rest of their body, with the rescuer supporting the head and neck without compressing the throat.
Instead of forceful strikes, the rescuer gives five gentle yet firm back thumps between the shoulder blades, using the heel of the hand. If this is unsuccessful, the infant is turned face-up, and the rescuer delivers five chest thrusts using two fingers on the center of the breastbone.
For adults who are visibly pregnant or severely obese, standard abdominal thrusts must be avoided entirely to prevent internal injury. In these instances, the rescuer must administer chest thrusts instead, focusing the force on the middle of the chest rather than the abdomen.