title: Intermittent positive pressure ventilation with constant positive end-expiratory pressure and alveolar recruitment manoeuvre during inhalation anaesthesia in horses undergoing surgery for colic, and its influence on the early recovery period.
abstract: OBJECTIVE
  To compare, ventilation using intermittent positive pressure ventilation (IPPV) with constant positive end-expiratory pressure (PEEP) and alveolar recruitment manoeuvres (RM) to classical IPPV without PEEP on gas exchange during anaesthesia and early recovery.
  
  
  METHODS
  Prospective randomized study.
  
  
  METHODS
  Twenty-four warm-blood horses, weight mean 548 ± SD 49 kg undergoing surgery for colic.
  
  
  METHODS
  Premedication, induction and maintenance (isoflurane in oxygen) were identical in all horses. Group C (n = 12) was ventilated using conventional IPPV, inspiratory pressure (PIP) 35-45 cmH2O; group RM (n = 12) using similar IPPV with constant PEEP (10 cmH2O) and intermittent RMs (three consecutive breaths PIP 60, 80 then 60 cmH2O, held for 10-12 seconds). RMs were applied as required to maintain arterial oxygen tension (PaO2) at >400 mmHg (53.3 kPa). Physiological parameters were recorded intraoperatively. Arterial blood gases were measured intra- and postoperatively. Recovery times and quality of recovery were measured or scored.
  
  
  RESULTS
  Statistically significant findings were that horses in group RM had an overall higher PaO2 (432 ± 101 mmHg) than those in group C (187 ± 112 mmHg) at all time points including during the early recovery period. Recovery time to standing position was significantly shorter in group RM (49.6 ± 20.7 minutes) than group C (70.7 ± 24.9). Other measured parameters did not differ significantly. The median (range) of number of RMs required to maintain PaO2 above 400 mmHg per anaesthetic was 3 (1-8).
  
  
  CONCLUSIONS
  Ventilation using IPPV with constant PEEP and RM improved arterial oxygenation lasting into the early recovery period in conjunction with faster recovery of similar quality. However this ventilation mode was not able to open up the lung completely and to keep it open without repeated recruitment.
  
  
  CONCLUSIONS
  This mode of ventilation may provide a clinically practicable method of improving oxygenation in anaesthetized horses.
authors.affiliation: Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany. klaus.hopster@tiho-hannover.de
authors.forename: Klaus
authors.initials: K
authors.lastname: Hopster
authors.forename: Sabine B R
authors.initials: SB
authors.lastname: Kästner
authors.forename: Karl
authors.initials: K
authors.lastname: Rohn
authors.forename: Berhard
authors.initials: B
authors.lastname: Ohnesorge
mesh_terms: D000208:Acute Disease; D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation / Q000379:methods / Q000662:veterinary*; D000818:Animals; D001784:Blood Gas Analysis / Q000662:veterinary; D003085:Colic / Q000097:blood / Q000601:surgery / Q000662:veterinary*; D006734:Horse Diseases / Q000601:surgery*; D006736:Horses; D007385:Intermittent Positive-Pressure Ventilation / Q000379:methods / Q000662:veterinary; D011175:Positive-Pressure Respiration / Q000379:methods / Q000662:veterinary*; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange