Final answer:
To ensure adequate chest compressions on a pregnant woman in cardiac arrest, perform the compressions between T4 and T9, and apply the left lateral uterine displacement to avoid aortocaval compression by the uterus.
Step-by-step explanation:
If a pregnant woman is in cardiac arrest and requires chest compressions, special considerations need to be made to ensure effective CPR. Ideally, the compression technique should be performed between the T4 and T9 vertebrae as specified in standard CPR guidelines. However, for a pregnant woman, the rescuer must also perform a manual adjustment, known as the "left lateral uterine displacement," or have an assistant gently push the uterus to the left.
This maneuver mitigates aortocaval compression by the enlarged uterus, which can limit blood return to the heart and decrease the effectiveness of chest compressions. Proper training in CPR for pregnant women is essential to perform these adjustments correctly without causing further injury. Continuous high-quality chest compressions are crucial until the heart resumes beating or the patient is declared deceased by a healthcare professional.