Which of the following is NOT a sign of effective ventilation?

Effective ventilation can be assessed through several signs that indicate that air is being adequately moved into the lungs and that oxygen exchange is occurring efficiently. One of the key signs is the rising of the chest with each breath; this indicates that the lungs are expanding and air is being inhaled. Additionally, improved oxygen saturation levels are critical measures of effective ventilation since they directly reflect the amount of oxygen in the blood. Finally, a return of patient responsiveness suggests that they are starting to recover and respond to stimuli, implying that the brain is receiving adequate oxygen.

A decreased heart rate, on the other hand, is not typically a sign of effective ventilation. Rather, an effective ventilation process aims to ensure that there is enough oxygen available, which often leads to a normalized or increased heart rate, especially in cases of initial hypoxia when the heart rate might be elevated. Thus, a decreased heart rate may indicate inadequate perfusion or other underlying issues rather than effective ventilation.