Mean arterial pressure/norepinephrine equivalent dose index as an early measure of initiation time for enteral nutrition in patients with shock: A prospective observational study.

ABSTRACT

OBJECTIVES: The aim of this study was to compare the predictive ability of the norepinephrine dose (NE), norepinephrine equivalent dose (NEQ), and mean arterial pressure (MAP)/NEQ index to predict the optimal time to initiate enteral nutrition in patients with shock on vasopressors. METHODS: We prospectively enrolled patients with shock who were receiving vasopressors and followed them for ≤28 d after enrollment. Patients who developed feeding intolerance (FI) during the follow-up period were allocated to the FI group and the remaining patients were allocated to the non-feeding intolerance (non-FI) group. The primary outcome was FI occurrence. The receiving operating characteristic curve (ROC) was used to evaluate the thresholds and predictive ability of NE, NEQ, and the MAP/NEQ index to predict FI. RESULTS: Of the 66 patients enrolled, 47 developed FI. The MAP/NEQ index showed good predictive ability 6 h before EN initiation. The threshold of the MAP/NEQ index for predicting FI was 417 mmHg·µg·kg·min-1 (specificity 52.9%, sensitivity 81%) with an area under the ROC curve (AUC) of 70.3% (95% confidence interval [CI], 55.1-85.5; P = 0.015). The threshold for the NE was 0.2 µg·kg/min-1 (specificity 47.1%, sensitivity 88.1%), with an AUC of 65.3% (95% CI, 48.2-82.5; P = 0.067), and that for the NEQ was 0.2 µg·kg/min-1 (specificity 47.1%, sensitivity 88.1%), with an AUC of 66.2% (95% CI, 49.3-83; P = 0.053). CONCLUSIONS: Compared with the NE and NEQ, it could be possible with the MAP/NEQ index to distinguish earlier whether patients with shock receiving vasopressors were suitable for initiation of EN, thereby avoiding FI.