Which of the following is not a manifestation of digitalis toxicity?

Digitalis toxicity can present with various symptoms, and understanding these manifestations is crucial in ICU settings. Among the options listed, premature atrial contractions with block are typically not recognized as a direct manifestation of digitalis toxicity.

Bradycardia is a common consequence of digitalis toxicity due to its effects on the autonomic nervous system, particularly through increased vagal tone. This slowing of the heart rate can be significant and is an important sign to monitor.

Visual disturbances, such as seeing halos around lights or changes in color perception, are also well-documented effects of digitalis toxicity. They typically result from the drug's action on the central nervous system and can provide a clue in identifying toxicity.

Nausea and vomiting are gastrointestinal symptoms that frequently occur in digitalis toxicity. These symptoms can arise from the drug's effects on the gastrointestinal tract or as part of the body's response to the toxicity.

In contrast, while premature atrial contractions can occur in patients taking digitalis, they are less specific and are not as prominently associated with toxicity as the other symptoms listed. This differentiates them as not being a hallmark of digitalis toxicity, underscoring the importance of recognizing the more classic symptoms associated with excessive digitalis levels.