CHICAGO – A few simple baseline variables predict if heart surgery patients will need early nutritional support after their operations, based on a review of more than 1,000 cardiac surgery patients from Johns Hopkins Hospital in Baltimore.
Nonelective surgery and a cardiopulmonary bypass time of 100 minutes or more, plus five preop variables – previous cardiac interventions; total albumin below 4 g/dL; total bilirubin at or above 1.2 mg/dL; white blood cell counts at or above 11,000/mcL; and hematocrit below 27% – predict the need for nutrition in the first few days after cardiac surgery, they found (J Am Coll Surg. 2015 Oct: 221;e70).
The Hopkins team has combined those factors into a risk score, with 4 points assigned for low albumin, 6 points for nonelective surgery, 6 points for low hematocrit, and 5 points for the other four variables, yielding a maximum score of 36 points.
The researchers developed the system after discovering that it sometimes took more than a week for cardiac patients who needed postop nutrition to get it. About 40% of patients with scores of 20 or higher will need early nutritional support, and those heart patients are now the ones at Hopkins who get a nutrition consult as soon as they return from the operating room, said Dr. Rika Ohkuma, a general surgery research fellow at Johns Hopkins. “The score can be used for risk stratification and has potential quality improvement implications related to early initiation of nutritional support in high-risk patients.”
Just 2% of patients who score 10 points or below need early nutrition, so consults are less pressing. About 9% of patients who score from 10-20 points will require nutrition, so consults are at the discretion of the physician, the investigators concluded.
Those insights came from a review of 1,056 adult heart cases in 2012. Just 87 patients (8%) had a postop consult for nutritional support. Most wound up with enteral feedings, but they started an average of 5 days after surgery. The handful that needed both parenteral and enteric feedings started them an average of 7 days after surgery.
Meanwhile, those 87 patients had significantly higher hospital mortality (29% vs. 3%), ventilator time (278 vs. 20 hours), and gastrointestinal complications (32% vs. 5%), and fewer discharges to home (49% vs. 84%) than did other patients.
The team thought that the delay in feeding might have had something to do with the poor outcomes, so “we tried to improve our behavior. We know that nutrition is beneficial for critically ill patients and that we need to start early, but there was no gold standard for when to start,” Dr. Ohkuma said.
The investigators came up with the risk score after figuring out how patients who needed nutrition differed from those who did not. They found, for example, that patients who have emergent surgery were more than three times as likely to have a nutrition consult than were those who had elective procedures.
Now when patients are admitted to the ICU after cardiac surgery, “we all know their [nutrition] score; if they are likely to need support, we immediately call the nutritional support service for a consult.” Patients no longer have to wait, Dr. Ohkuma said.
The researchers launched a prospective study in January 2015. Nutritional needs were addressed sooner, at about postop day 4, for the 70 patients who have needed, and mortality seems to be dropping.
The investigators have no relevant disclosures.