title: Respiratory acidosis in adolescents with anorexia nervosa hospitalized for medical stabilization: a retrospective study.
abstract: OBJECTIVE
  To examine the effect of malnutrition due to anorexia nervosa (AN) on venous blood gases of adolescents with AN hospitalized for medical stabilization.
  
  
  METHODS
  This retrospective study included 45 adolescents with recent onset (<1 year) AN diagnosed by DSM-IV criteria and excluded subjects with a history of lung disease.
  
  
  RESULTS
  Mean (± SD) age at hospitalization was 15.0 ± 2.0 years; time from onset of symptoms was 6.8 ± 3.0 months; body mass index (BMI) was 15.2 ± 1.5 kg/m(2) ; and minimal nocturnal heart rate (MNHR) was 39.8 ± 7.2 beats/min. On admission, pH was 7.32 ± 0.02, pCO(2) was 53.8 ± 4.6 mm Hg, and HCO(3) was 28.1 ± 2.1 mEq/l. Significant changes (p < .001) occurred during the relatively short hospitalization (9.7 ± 5.1 days): venous pH increased, pCO(2) decreased, HCO(3) decreased, MNHR increased, and heart rate orthostasis decreased. Mild respiratory acidosis (pH < 7.35 and pCO(2) > 45 mm Hg) was observed in 78% of the patients on admission and only in 35% at discharge (p = .0003). Positive correlations were found between % of weight loss and pCO(2) on admission and between BMI on admission and the delta pCO(2) during hospitalization.
  
  
  CONCLUSIONS
  Mild respiratory acidosis is common in adolescents with recently diagnosed AN, hospitalized for medical stabilization. Respiratory acidosis improves with bed rest and refeeding. The clinical significance of these findings should be further evaluated.
authors.affiliation: Department of Pediatrics, Bnai Zion Medical Center, The Bruce Rappaport Faculty of Medicine, Haifa, Israel.
authors.forename: Nogah C
authors.initials: NC
authors.lastname: Kerem
authors.forename: Arieh
authors.initials: A
authors.lastname: Riskin
authors.forename: Elvira
authors.initials: E
authors.lastname: Averin
authors.forename: Isaac
authors.initials: I
authors.lastname: Srugo
authors.forename: Amir
authors.initials: A
authors.lastname: Kugelman
mesh_terms: D000142:Acidosis, Respiratory / Q000175:diagnosis / Q000209:etiology*; D000293:Adolescent; D000856:Anorexia Nervosa / Q000150:complications* / Q000175:diagnosis; D002648:Child; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D055815:Young Adult