Effect of Probiotics and Therapeutic Additives on the Osmolality of Pasteurized Donor Human Milk

This study aims to examine changes in the osmolality of pasteurized donor human milk (PDHM) following the addition of probiotics and commonly used neonatal additives.

The osmolality of PDHM was measured at 10 minutes using a calibrated osmometer by a technician blinded to the probiotics and additives used in the study. The osmolality of 5 mL of PDHM was measured after the addition of four different probiotics and commonly used additives, including caffeine, cephalexin, domperidone, esomeprazole, fluconazole, furosemide, ibuprofen, lansoprazole, levetiracetam, paracetamol, phenobarbitone, sildenafil, and ursodeoxycholic acid, administered separately in therapeutic doses. The osmolality of the oral iodinated non-ionic contrast agent (Omnipaque) was measured after 1:2 and 1:4 dilution with sterile water. The volume of PDHM required to be added to each additive to keep the osmolality below 450 mOsm/kg, as recommended by the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN), was calculated.

The mean osmolality of PDHM was 256 mOsm/kg, which, on reconstitution with most additives, exceeded 450 mOsm/kg. The osmolality of pure additives ranged from 161 to >2000 mOsm/kg. There was a significant increase in the osmolality of PDHM beyond the recommended 450 mOsm/kg with most additives, except caffeine, cephalexin, esomeprazole, fluconazole, furosemide, lansoprazole, and sildenafil. A maximum increase in osmolality to 1723 mOsm/kg (range 260-1723 mOsm/kg) was observed with probiotics. Domperidone, ibuprofen, levetiracetam, paracetamol, phenobarbitone, and ursodeoxycholic acid increased the osmolality beyond 450 mOsm/kg. The osmolality of the iodinated non-ionic contrast agent (Omnipaque), when diluted with sterile water in a 1:4 ratio, was 461 mOsm/kg.

The addition of probiotics to PDHM increases osmolality and requires appropriate dilution to maintain levels below the recommended 450 mOsm/kg. Therapeutic additives such as domperidone, ibuprofen, levetiracetam, paracetamol, phenobarbitone, and ursodeoxycholic acid also increase the osmolality of PDHM and require appropriate dilution. Future research should focus on developing probiotics and additives with lower osmolality to improve safety in neonates.