title: Pulmonary gas exchange and plasma lactate in horses with gastrointestinal disease undergoing emergency exploratory laparotomy: a comparison with an elective surgery horse population.
abstract: OBJECTIVE
  To characterize pulmonary gas exchange and arterial lactate in horses with gastrointestinal disease undergoing anesthesia, compared with elective surgical horses, and to correlate these variables with postoperative complications and mortality.
  
  
  METHODS
  Prospective clinical study.
  
  
  METHODS
  Horses undergoing emergency laparotomy for acute intestinal disease (n = 50) and healthy horses undergoing elective surgery in dorsal recumbency (n = 20).
  
  
  METHODS
  Arterial blood gas analysis was performed at predetermined intervals on horses undergoing a standardized anesthetic protocol. Alveolar-arterial oxygen gradient was calculated. Predictive factors for postoperative complications and death in colic horses were determined.
  
  
  RESULTS
  Arterial oxygen tension (P(a) O(2)) varied widely among horses in both groups. P(a) O(2) significantly increased in the colic group after exteriorization of the ascending colon. P(a) O(2) and alveolar-arterial oxygen gradient were not significantly different between groups, and neither were correlated with horse outcome. Arterial lactate in recovery ≥ 5 mmol/L was associated with a 2.25 times greater relative risk of complications and lactate ≥ 7 mmol/L was associated with a 10.5 times higher relative risk of death.
  
  
  CONCLUSIONS
  Colic horses in this population were not more likely to be hypoxemic than elective horses, nor was gas exchange impaired to a greater degree in colic horses relative to controls. Arterial lactate sampled immediately after anesthetic recovery was predictive for postoperative complications and death.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
authors.forename: Annette M
authors.initials: AM
authors.lastname: McCoy
authors.forename: Eileen S
authors.initials: ES
authors.lastname: Hackett
authors.forename: Ann E
authors.initials: AE
authors.lastname: Wagner
authors.forename: Khursheed R
authors.initials: KR
authors.lastname: Mama
authors.forename: Dean A
authors.initials: DA
authors.lastname: Hendrickson
mesh_terms: D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation / Q000662:veterinary; D000818:Animals; D003085:Colic / Q000097:blood / Q000601:surgery / Q000662:veterinary*; D017558:Elective Surgical Procedures / Q000662:veterinary; D004638:Emergency Treatment / Q000662:veterinary*; D005767:Gastrointestinal Diseases / Q000097:blood / Q000601:surgery / Q000662:veterinary*; D006734:Horse Diseases / Q000097:blood / Q000601:surgery*; D006736:Horses; D019344:Lactic Acid / Q000097:blood*; D007813:Laparotomy / Q000401:mortality / Q000662:veterinary*; D011183:Postoperative Complications / Q000453:epidemiology / Q000662:veterinary; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D016896:Treatment Outcome
chemical_list: D019344:Lactic Acid