title: Breath metabolite response to major upper gastrointestinal surgery.
abstract: BACKGROUND
  Esophagectomy and gastrectomy are associated with profound metabolic changes and significant postoperative morbidity. The aim of this prospective clinical study was to determine whether breath analysis can offer novel insight into the surgical metabolic response and identify biomarkers of postoperative complications, including lung injury.
  
  
  METHODS
  Breath samples were collected preoperatively and at 24, 48, 72, 96 and 168 h after esophagectomy (n = 25) and gastrectomy (n = 15). Targeted analysis of four prominent breath metabolites was performed by selected ion flow-tube mass spectrometry. Patients with nonsurgical lung injury (community-acquired pneumonia) were recruited as positive controls.
  
  
  RESULTS
  Perioperative starvation and subsequent reintroduction of nutritional input were associated with significant changes in breath acetone levels. Breath acetone levels fell after esophagectomy (P = 0.008) and were significantly lower than in gastrectomy patients at postoperative time points 48 (P < 0.001) and 72 h (P < 0.001). In contrast, concentrations of isoprene increased significantly after esophagectomy (P = 0.014). Pneumonia was the most frequently observed postoperative complication (esophagectomy 36% and gastrectomy 7%). The concentration of hydrogen cyanide was significantly lower in the breath of patients who developed pneumonia, 72 h after surgery (P = 0.008). Exhaled hydrogen cyanide (P = 0.001) and isoprene (P = 0.014) were also reduced in patients with community-acquired pneumonia compared with healthy controls.
  
  
  CONCLUSIONS
  Selected ion flow-tube mass spectrometry can be used as a totally noninvasive resource to monitor multiple aspects of metabolic alterations in the postoperative period. Exhaled concentrations of several prominent metabolites are significantly altered after major upper gastrointestinal surgery and in response to pneumonia.
authors.affiliation: Department of Surgery and Cancer, Imperial College London, St Mary's Hospital, London, United Kingdom.
authors.forename: Piers R
authors.initials: PR
authors.lastname: Boshier
authors.affiliation: Department of Surgery and Cancer, Imperial College London, St Mary's Hospital, London, United Kingdom.
authors.forename: Vikash
authors.initials: V
authors.lastname: Mistry
authors.affiliation: Department of Surgery and Cancer, Imperial College London, St Mary's Hospital, London, United Kingdom.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Cushnir
authors.affiliation: Department of Respiratory Medicine, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom.
authors.forename: Onn Min
authors.initials: OM
authors.lastname: Kon
authors.affiliation: Department of Respiratory Medicine, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Elkin
authors.affiliation: Department of Microbiology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom.
authors.forename: Sally
authors.initials: S
authors.lastname: Curtis
authors.affiliation: Section of Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Imperial College London, Chelsea and Westminster Hospital, London, United Kingdom; Department of Anaesthetics, Harefield Hospital, The Royal Brompton and Harefield NHS Foundation Trust, Harefield, Middlesex, United Kingdom; Department of Anaesthesia and Intensive Therapy, Semmelweiss University, Budapest, Hungary. Electronic address: n.marczin@imperial.ac.uk.
authors.forename: Nandor
authors.initials: N
authors.lastname: Marczin
authors.affiliation: Department of Surgery and Cancer, Imperial College London, St Mary's Hospital, London, United Kingdom.
authors.forename: George B
authors.initials: GB
authors.lastname: Hanna
mesh_terms: D019342:Acetic Acid / Q000032:analysis; D000096:Acetone / Q000032:analysis; D000368:Aged; D001944:Breath Tests; D002070:Butadienes / Q000032:analysis; D016629:Esophagectomy; D005260:Female; D005743:Gastrectomy; D045782:Hemiterpenes / Q000032:analysis; D006801:Humans; D006856:Hydrogen Cyanide / Q000032:analysis; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D009752:Nutritional Status; D018384:Oxidative Stress; D010420:Pentanes / Q000032:analysis; D059035:Perioperative Period; D011183:Postoperative Complications / Q000175:diagnosis* / Q000378:metabolism*; D011446:Prospective Studies
chemical_list: D002070:Butadienes; D045782:Hemiterpenes; D010420:Pentanes; C005059:isoprene; D000096:Acetone; D006856:Hydrogen Cyanide; D019342:Acetic Acid
keywords: Esophagectomy; Exhaled breath; Gastrectomy; Metabolism; Pneumonia; Selective ion flow tube mass spectrometry