The abdominal thrust maneuver, commonly known as the Heimlich maneuver, is a first-aid procedure designed to save a person from choking due to a foreign body airway obstruction. Developed in the 1970s, the technique involves applying quick, upward pressure to the abdomen to compress the diaphragm. This action forces residual air from the lungs, creating an artificial cough powerful enough to dislodge the lodged object. While widely taught, the maneuver is not a guaranteed solution, as its success hinges on proper execution and the nature of the blockage.
Statistical Effectiveness and Why It Fails
The Heimlich maneuver is highly effective in the majority of cases where a conscious adult has a complete airway obstruction. The underlying physiological principle is sound: the rapid increase in intra-thoracic pressure generates an expulsive force greater than a natural cough. However, the maneuver is not universally successful, and failure can often be traced to procedural or physiological limitations.
One common reason for failure is the improper application of the technique, such as using insufficient force or placing the hands incorrectly below the ribcage. Forceful upward and inward thrusts must be applied to the epigastric region to adequately compress the diaphragm and lung capacity.
The effectiveness is also reduced if the obstruction is only partial, as the maneuver can potentially turn a partial blockage into a complete one. Objects that are large, irregularly shaped, or deeply lodged may resist the pressure generated by the artificial cough. A delay in intervention also decreases the chance of success, as the victim’s reserve air volume diminishes quickly.
Adapting the Technique for Special Cases
The standard abdominal thrust technique requires modification for certain groups to ensure safety and maximize effectiveness.
Infants
Standard abdominal thrusts are not recommended for infants under one year old due to the risk of internal injury. Instead, the protocol involves five firm back blows delivered between the shoulder blades, followed by five gentle chest thrusts. The infant is positioned face-down and then face-up on the rescuer’s forearm during the procedure.
Pregnant or Obese Individuals
When assisting a pregnant individual or a person with obesity, the rescuer cannot effectively wrap their arms around the abdomen or may risk injury. In these scenarios, the technique is adjusted to use chest thrusts, which are applied directly over the center of the breastbone. These thrusts use the same rapid, inward motion but avoid pressure on the lower abdomen.
Self-Administration
An individual choking alone can perform a modified version of the maneuver on themselves. This involves making a fist and placing it just above the navel, then grasping the fist with the other hand and thrusting inward and upward. A more forceful self-administered technique involves leaning over a rigid, fixed object, such as the back of a chair or a countertop, and quickly thrusting the upper abdomen against the edge.
Immediate Steps Following Failure
When the initial cycles of the Heimlich maneuver do not dislodge the obstruction, the rescuer must immediately continue life-saving measures. If a second person is present, they should call emergency services immediately; otherwise, the rescuer must call as soon as possible. The rescuer should continue the cycles of five abdominal thrusts, or the appropriate alternative for special cases, without interruption.
This repetition is maintained until the object is expelled, the person begins to breathe, or the victim loses consciousness. If the person becomes unresponsive, the rescuer must gently lower them to the floor and begin Cardiopulmonary Resuscitation (CPR).
Before starting rescue breaths, the rescuer should check the victim’s mouth for the foreign object, removing it only if it is clearly visible and easily reachable. Chest compressions, a component of CPR, can also help dislodge the obstruction by creating pressure changes within the chest cavity.