TITLE:
Pyloric Stenosis and Nonbilious Vomiting in Infants: Negative Base Excess and Hypercapnia—Two Opposing Points of One Scale a Comparative Case Series
AUTHORS:
Ralf-Bodo Tröbs, Tomasz Baranski, Andreas Lipphaus, Matthias Nissen
KEYWORDS:
Pyloric Stenosis, Nonbilious Vomiting, Hypoventilation, Base Excess, Hypercapnia
JOURNAL NAME:
Open Journal of Pediatrics,
Vol.13 No.1,
January
16,
2023
ABSTRACT: Background: Blood pH and bicarbonate estimations are basal acid-base laboratory tests
that are performed in infants with infantile hypertrophic pyloric stenosis
(IHPS). This study aimed to define the clinical value of pCO2 and BE
in infants suspected to have IHPS. Methods: We collected data from 80
“surgical” infants younger than 100 days with prolonged nonbilious vomiting who
were suspected to have IHPS. In 65 infants, pyloric stenosis was confirmed, and
15 infants had nonsurgical conditions. Capillary blood was tested for standard
acid-base parameters and lactate. The two groups were compared. Results: Eighty-eight
percent of the IHPS infants had elevated standard bicarbonate levels (st
bicarb) > 25 mmol/l, and 60% had BE > 3.5 mmol/l; 12% of the infants
showed hypercapnia (pCO2 ≥ 50 mmHg) associated with markedly
increased standard bicarbonate and BE. Infants with nonsurgical vomiting were
older at admission (p = 0.002), had a longer duration of vomiting (p 2 (p = 0.021), lower st bicarb (p Conclusions: In infants with IHPS/nonbilious vomiting, acid-base
analysis (ABA) is equivocal or inconclusive. These findings may be misleading
and could result in a false clinical decision. Nonsurgical vomiting is
associated with a lower degree of alkalosis, normocapnia to slight hypercapnia
and a base deficit. However, even infants with IHPS may present with a negative
BE. In infants with IHPS and severe alkalosis, hypercapnia carries a risk for
respiratory depression. Monitoring the infant’s respiration allows for the
early detection of respiratory deterioration.