Final answer:
Hyperventilation in laboring clients causes respiratory alkalosis, and breathing into a paper bag is the correct action for a nurse to relieve the condition by rebalancing blood CO₂ levels.
Step-by-step explanation:
Hyperventilation often occurs in the laboring client and can lead to respiratory alkalosis, which is a condition where there is a primary deficiency of carbonic acid and CO₂ in the blood, resulting in overly alkaline blood pH. This happens due to excessive CO₂ being exhaled from the lungs. To relieve this condition, the nurse should have the client breathe into a paper bag. This action helps by re-inhaling some of the exhaled CO₂, thereby correcting the imbalance in the blood's carbon dioxide levels and alleviating symptoms of respiratory alkalosis.