How is the effectiveness of nitrous oxide assessed after administration?

The effectiveness of nitrous oxide is primarily assessed by monitoring behavior and vital signs due to its relatively rapid onset and short duration of action. After administration, patients typically exhibit signs of sedation, relaxation, and decreased anxiety, which can be observed through their behavior. This might include their level of responsiveness, comfort, and ability to communicate.

Vital signs, such as heart rate and respiratory rate, are also critical indicators. Changes in these parameters can reflect the patient's physiological response to the nitrous oxide. For instance, an increase in respiratory rate might indicate that the patient is feeling anxious or uncomfortable, while a decrease could suggest deeper sedation.

The other options do not directly reveal the immediate effectiveness of nitrous oxide. For instance, measuring blood pressure may not provide specific insight into the sedation level, as it can be affected by various factors unrelated to the nitrous oxide itself. Checking patient weight is irrelevant in assessing the immediate effects of the gas on sedation and pain management. Observing skin color, while useful in monitoring for potential adverse reactions, does not reflect the subjective experience of sedation and pain relief that nitrous oxide is intended to provide. Thus, behavior and vital signs offer the most immediate and relevant means to evaluate effectiveness after administration.