Parenterally administered amino acids decrease acute mortality in fasting patients with aspiration pneumonia: A retrospective study

Background & aims

To prevent food aspiration, numerous patients with aspiration pneumonia are restricted from eating early during their hospital stay. Although they receive parenteral nutrition (PN) on a fasting regimen, the optimal dose and composition remain unknown. The current study aimed to investigate whether PN with amino acids (AA) affects 30-day mortality of patients with aspiration pneumonia.

Methods

This retrospective study included 115 patients with aspiration pneumonia who were admitted to our hospital between November 2019 and November 2023. All patients followed the clinical pathway for aspiration pneumonia, had been fasting for >5 days, and received PN alone on admission. Given that treating physicians could modify the standard PN regimen by including AA, some patients received maintenance infusion without AA. The patients were divided in those who received PN with AA (>15 g/day, AA group) and those who did not (0–15 g/day, non-amino acid [NAA] group). The primary endpoint was 30-day in-hospital mortality.

Results

Among the 115 patients, 65 (57 %) received PN with AA from days 2–5. No significant differences in background characteristics and severity of pneumonia were observed, except for heart failure. Serum albumin levels were significantly lower in the AA group than in the NAA group (median, 2.9 vs. 3.2 g/dL; P = 0.003). Median energy intake on days 2 and 5 were significantly higher in the AA group than in the NAA group (day 2: 10.7 vs. 3.7 kcal/kg/day; day 5: 10.6 vs. 4.2 kcal/kg/day, respectively). The AA group had a median protein dose of 0.76 and 0.74 g/kg/day on days 2 and 5, respectively, whereas the NAA group had a median protein dose of 0.00 g/kg/day on both days. After adjusting for age, sex, body mass index, albumin, and pneumonia severity, 30-day in-hospital mortality was lower in the AA group than in the NAA group (hazard ratio, 0.31; 95 % confidence interval, 0.10–0.99).

Conclusions

Early PN with AA may play an important role in improving 30-day in-hospital mortality among fasting patients with aspiration pneumonia after hospital admission.