Intraoperative intravenous fluid management practice varies greatly between anesthesiologists. Postoperative fluid based weight gain is associated with major morbidity. Postoperative respiratory complications are associated with increased morbidity, mortality and hospital costs. The literature shows conflicting data regarding intraoperative fluid resuscitation volume. No large-scale studies have focused on intraoperative fluid management and postoperative respiratory dysfunction.

Hypotheses:

Primary - Liberal intraoperative fluid resuscitation is associated with an increased risk of 30 day mortality Secondary - Liberal intraoperative fluid resuscitation is associated with increased likelihood of postoperative respiratory failure, pulmonary edema, reintubation, atelectasis, acute kidney injury and peri-extubation oxygen desaturation.

Inclusion Criteria:

• Ages 18 upwards
• Tracheally intubated at the beginning of the procedure and extubated at the end of the procedure

Exclusion Criteria:

• Cases where the subject had additional surgeries within the previous four weeks
• Ages under 18

All surgical patients aged 18 upwards receiving general anesthesia at Massachusetts General Hospital between January 2007 and November 2012