CVICU nursing might be described as hard because it requires a very specialized knowledge set and demands a high level of critical thinking. Other critical care units also require these skills, but there is a stereotype that cardiothoracic critical care nurses are especially intense and passionate about their work.

In the nursing community, the CVICU (Cardiovascular Intensive Care Unit) and the Neuro ICU are frequently cited as the most difficult, though for different reasons. The CVICU is notoriously intense because of its "high-acuity" patients who are often on complex life-support machines like ECMO, Impellas, or CRRT. The physiological monitoring is constant, and the "margin for error" is virtually zero; a tiny change in a medication drip can have immediate, life-threatening consequences. On the other hand, the Neuro ICU is often considered the hardest due to the "emotional and cognitive load." Nurses deal with traumatic brain injuries and strokes where the patient’s personality may change or their prognosis is extremely grim, requiring difficult conversations with families. Other contenders include the PICU (Pediatric ICU) due to the emotional toll of caring for sick children. Ultimately, "hardness" is subjective: some find the fast-paced, high-tech nature of the CVICU exhilarating, while others find the unpredictability and slow-moving sadness of the Neuro ICU far more taxing.