Pupillary signs that suggest deep anesthesia include which of the following?

Pupillary signs that suggest deep anesthesia include which of the following?

• A. Central, dilated pupils with absent PLR
• B. Pupils constricted with brisk PLR
• C. Pupils mid-dilated with reactive PLR
• D. Pupils small and nonresponsive to light

Answer: (A)

Pupillary signs reflect how suppressive the brain is and how well the brainstem reflexes are functioning. The pupillary light reflex requires an intact midbrain circuit and parasympathetic output to constrict the pupil. When anesthesia is very deep or the brainstem is significantly depressed, this reflex can disappear and the pupils can become larger because sympathetic tone dominates or parasympathetic pathways are suppressed. Central, dilated pupils with absent pupillary light reflex is the clearest indicator of profound CNS depression from deep anesthesia. The pupil is not only dilated but also nonreactive to light, signaling that the neural pathways mediating the reflex are not functioning. If the pupils are constricted with a brisk light reflex, the depth of anesthesia is not at a dangerous, deep level and the brainstem reflexes are preserved. A mid-dilated pupil with a reactive reflex suggests an intermediate level of depression where some reflexes remain intact. Small, nonreactive pupils could occur with opioid effects or other etiologies, but they do not specifically point to the same profound CNS suppression indicated by dilated, nonreactive pupils.

Pupillary signs reflect how suppressive the brain is and how well the brainstem reflexes are functioning. The pupillary light reflex requires an intact midbrain circuit and parasympathetic output to constrict the pupil. When anesthesia is very deep or the brainstem is significantly depressed, this reflex can disappear and the pupils can become larger because sympathetic tone dominates or parasympathetic pathways are suppressed.

Central, dilated pupils with absent pupillary light reflex is the clearest indicator of profound CNS depression from deep anesthesia. The pupil is not only dilated but also nonreactive to light, signaling that the neural pathways mediating the reflex are not functioning.

If the pupils are constricted with a brisk light reflex, the depth of anesthesia is not at a dangerous, deep level and the brainstem reflexes are preserved. A mid-dilated pupil with a reactive reflex suggests an intermediate level of depression where some reflexes remain intact. Small, nonreactive pupils could occur with opioid effects or other etiologies, but they do not specifically point to the same profound CNS suppression indicated by dilated, nonreactive pupils.