Final answer:
In a case of respiratory arrest with poor perfusion in a child, begin cardiopulmonary resuscitation (CPR) immediately, following the standard CPR guidelines of chest compressions combined with artificial respiration, and continue until medical assistance arrives or the child recovers.
Step-by-step explanation:
If you are caring for a child who is in respiratory arrest with a central pulse of 55 bpm and showing signs of poor perfusion, you need to take immediate emergency action. The child should not be placed in the recovery position to simply monitor until help arrives; instead, you need to begin cardiopulmonary resuscitation (CPR) immediately.
According to medical guidelines, CPR involves compressions to the chest to manually pump blood through the heart and into the systemic and pulmonary circuits, especially vital for brain function. For a child, you would use one or two hands, depending on the size of the child, pressed in the center of the chest to compress the chest at least 5 cm deep, at a rate of around 100 compressions per minute, which coincides with the beat of the song 'Staying Alive' by the Bee Gees.
In the described scenario with a child showing poor perfusion and a low heart rate (< 60 bpm for infants), along with respiratory arrest, it is crucial to provide ventilatory support along with chest compressions. This is because both airway and breathing are compromised; hence artificial respiration, in combination with chest compressions, would be required. CPR should be continued until the child shows signs of recovery or until professional medical help takes over.