We conducted a prospective, observational study to determine the incidence of feeding intolerance (FI) within 7 d of initiating enteral nutrition (EN) in patients undergoing cardiopulmonary bypass (CPB) and to evaluate the association between FI and a poor prognosis. Patients who underwent CPB surgery at Fujian Medical University Union Hospital between March 2020 and June 2020 were enrolled. According to the presence or absence of FI within 7 d after EN, patients were divided into FI and non-FI groups. According to the occurrence of a poor prognosis (death, gastrointestinal haemorrhage, acute kidney injury, liver insufficiency, neurological events (cerebral infarction, cerebral haemorrhage and epilepsy) and prolonged mechanical ventilation (> 48 h)), patients were divided into poor prognosis and good prognosis groups. The mean age of the 237 CPB patients, including 139 men and ninety-eight women, was 53·80 (sd 12·25) years. The incidence of FI was 64·14 %. Multivariate logistic regression analysis showed factors independently associated with poor prognosis after CPB included FI (OR 2·138; 95 % CI 1·058, 4·320), age (OR 1·033; 95 % CI 1·004, 1·063), New York Heart Association (NYHA) class III/IV cardiac function (OR 2·410; 95 % CI 1·079, 5·383), macrovascular surgery (OR 5·434; 95 % CI 1·704, 17·333) and initial sequential organ failure assessment score (OR 1·243; 95 % CI 1·010, 1·530). Thus, the incidence of FI within 7 d of EN after CPB was high, which was associated with a poor prognosis.

A randomized double-blind study was carried out on 20 patients after coronary artery bypass surgery to investigate the effects of graded doses of dopexamine hydrochloride or placebo on systemic haemodynamic responses and renal vascular resistance index (RVRI) measured using Doppler ultrasound. Pre-operatively, all patients had good left ventricular function and normal renal function. Eleven were allocated randomly to receive incremental infusions of dopexamine 0.5, 1, 2, and 4 μg kg−1 for 40 min each, and nine received corresponding infusions of placebo. One patient was withdrawn from the dopexamine group because of tachycardia. In the remaining 19, heart rate (HR) and cardiac index (CI) were significantly (P < 0.05) increased from base-line with dopexamine: the HR values with dopexamine differed significantly from those with placebo at the 2 and 4 μg kg−1 min−1 dose, and at 4 μg kg−1 min−1 for CI. Systemic vascular resistance index (SVRI) fell significantly in both groups: the reduction was significantly greater with dopexamine 4 μg kg−1 min−1 than with the corresponding infusion of placebo. RVRI increased and urine output decreased significantly during the infusions in both groups, but with no significant difference between groups. There were no changes in systemic arterial pressures, pulmonary artery occlusion pressures, stroke volume index or left ventricular stroke work index. Where changes from base-line occurred in either group, they had not returned to base-line within 40 min of stopping the infusions (except perhaps for CI in the dopexamine group). Dopexamine appears to offer no particular protection to the renal vascular bed.