Parenteral amino acid and metabolic acidosis in premature infants.
BACKGROUND
Aggressive parenteral nutrition (PN) including amino acids is recommended for low-birth-weight infants to prevent energy and protein deficit. Their impact on acid-base homeostasis has not been examined.


METHODS
We investigated the impact of dose and duration of parenteral amino acids, with cysteine, on acid-base parameters in 122 low-birth-weight infants. Premature infants <or=32 weeks, <or=1850 g, and receiving parenteral amino acids at 1.5 g/kg/d for an extended period (>24 hours), or 3 g/kg/d for a short (5 hour), extended (24 hour), or prolonged (3-5 days) duration were included in the study. Data were obtained at age 0-3 days (n = 43) or, when clinically stable, age 3-5 days (n = 49). Data from 30 infants, matched for birth weight and gestational age, receiving PN during the first 5 days after birth were also obtained. Acidosis was defined as pH <7.25.


RESULTS
Acidosis was evident in all infants between 2 and 5 days after birth. Infants with large patent ductus arteriosus (PDA) exhibited significantly (p < .05) lower pH early, had higher blood urea nitrogen levels (26 +/- 9 vs 18 + 8 mg/dL; p < .05), and had greater weight loss ( approximately 17% of birth weight) when compared with infants without PDA. Gestational age, weight loss, and patent ductus arteriosus accounted for 65% of variance in acidosis.


CONCLUSIONS
Low-birth-weight infants develop metabolic acidosis between 2 and 5 days after birth, irrespective of dose and duration of parenteral amino acid administration. Careful management of parenteral fluids and comorbidities may lower the incidence of acidosis and promote protein accretion.
Jadhav
Pushkaraj
P
Schwartz Center for Metabolism and Nutrition and Department of Pediatrics, Case Western Reserve University, MetroHealth Medical Center, Cleveland, Ohio, USA.
Parimi
Prabhu S
PS
Kalhan
Satish C
SC
D000136:Acid-Base Equilibrium / Q000187:drug effects* / Q000502:physiology; D000138:Acidosis / Q000453:epidemiology* / Q000517:prevention & control; D000596:Amino Acids / Q000008:administration & dosage*; D001639:Bicarbonates / Q000097:blood; D001724:Birth Weight; D001806:Blood Urea Nitrogen; D004305:Dose-Response Relationship, Drug; D004374:Ductus Arteriosus, Patent / Q000097:blood / Q000150:complications; D005260:Female; D005865:Gestational Age; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007227:Infant Nutritional Physiological Phenomena; D007230:Infant, Low Birth Weight / Q000097:blood / Q000254:growth & development; D007231:Infant, Newborn / Q000097:blood / Q000254:growth & development; D007234:Infant, Premature / Q000097:blood / Q000254:growth & development*; D008297:Male; D010288:Parenteral Nutrition; D013997:Time Factors; D015430:Weight Gain
D000596:Amino Acids; D001639:Bicarbonates