The purpose of this study is to determine whether prophylactic nasal continuous positive
airway pressure (nCPAP) in the post-anaesthesia care unit (PACU) improves post-operative
pulmonary function following elective bowel surgery. The investigators hypothesize that one
hour of nCPAP in the PACU will result in a higher partial pressure of arterial oxygen (PaO2)
when compared to the standard treatment of low flow oxygen applied by face mask.