• Change in postoperative maximal inspiratory mouth pressure from POD1 to POD3 [ Time Frame: 3 days ]
  Maximal inspiratory mouth pressure [cmH2O] is measured on the first and third postoperative day to asses the change
• Change in postoperative maximal expiratory mouth pressure from POD1 to POD3 [ Time Frame: 3 days ]
  Maximal expiratory mouth pressure [cmH2O] is measured on the first and third postoperative day to asses the change
• Length of surgical incision [ Time Frame: Day 1 ]
  The length of the surgical incision [cm] will be measured on the first postoperative day
• Heart Rate Variability (HRV) [ Time Frame: 3 days ]
  HRV assessed preoperatively - POD3, if this is not achievable then from POD0 - POD3
• The occurence of per- and postoperative cardiac arrhythmias (until POD3) [ Time Frame: 3 days ]
  The occurence of postoperative cardiac arrhythmia the first three days following surgery, with cardiac arrhythmia defined as:

  • Atrial fibrillation (AF) or
  • Atrial Flutter (AFL) or
  • Ventricular Tachycardia (VT- both monomorphic and polymorphic types) or
  • Recurrent sustained ventricular tachycardia (RSVT) or
  • Ventricular fibrillation (VF) or
  • Torsade de Pointes (TDP) or
  • 2nd degree atrioventricular (AV) block or
  • 3rd degree atrioventricular (AV) block
• The occurence of per- and postoperative ischemic ECG changes (until POD3) [ Time Frame: 3 days ]
  The occurence of per- and postoperative ischemic ECG changes the first three days following surgery, defined as:

  • ST-depression ≥ 0,5 mm at the J-point in ≥ 2 contiguous leads or
  • Inverted T waves ≥ 1 mm in ≥2 contiguous leads that have dominant R waves or
  • ST-elevation ≥ 1 mm in ≥ 2 contiguous leads, however
  • ST-elevation in V2-V3 ≥ 2,5 mm for males < 40 years of age in ≥ 2 contiguous leads
  • ST-elevation in V2-V3 ≥ 2,0 mm for males ≥ 40 years of age in ≥ 2 contiguous leads
  • ST-elevation in V2-V3 ≥ 1,5 mm for females in ≥ 2 contiguous leads) or
  • In V2-V3: Any q wave ≥ 0,02 seconds,
  • In other leads: Q wave ≥ 0,03 seconds and > 1 mm deep in ≥ 2 contiguous leads.
• The occurence of postoperative hypoxemia during the first three postoperative days [ Time Frame: 3 days ]
  The occurence of postoperative hypoxemia during the first three postoperative days, defined as:

  • the number of declines in saturation of 4 % (or more) lasting 20 seconds (or more) or
  • number of desaturation episodes below 90 % or
  • time (minutes( spent below 90 %,

1. Describe the incidence of postoperative hypoxemia after major emergency abdominal surgery as well as correlate this to clinical outcomes.
2. Investigate the association between postoperative pulmonary complications and respiratory muscle dysfunction.
3. Investigate the association between the length and type of incision as well as the distance to the xiphoid process and respiratory muscle dysfunction.
4. Investigate the association between postoperative hypoxemia, myocardial ischemia and ischemic electrocardiographic (ECG) changes within three days of major emergency abdominal surgery
5. Describe the incidence of postoperative cardiac arrhythmias within three days of major emergency abdominal surgery and the association with postoperative cardiovascular complications within 30 days, 90 days and 1 year of surgery.
6. Describe the association between HRV and postoperative cardiovascular and non-cardiovascular complications within 30 days, 90 days and 1 year of surgery

• Pulmonary Complication
• Cardiovascular Complication
• Postoperative Complications

Inclusion Criteria:

• Surgery within 72 hours of an acute admission to the Department of Surgery or an acute reoperation.
• Major gastrointestinal surgery on the gastrointestinal tract.

This will include:

• Open, laparoscopic, or laparoscopically-assisted procedures
• Procedures involving the stomach, small or large bowel, or rectum for conditions such as perforation, ischemia, abdominal abscess, bleeding or obstruction
• Washout/evacuation of intra-peritoneal abscess (unless due to appendicitis or cholecystitis - excluded, see below)
• Washout/evacuation of intra-peritoneal hematoma
• Bowel resection/repair due to incarcerated umbilical, inguinal and femoral hernias (but not hernia repair without bowel resection/repair)
• Bowel resection/repair due to obstructing/incarcerated incisional hernias provided the presentation and findings were acute
• Laparotomy/laparoscopy with inoperable pathology (e.g. peritoneal/hepatic metastases)
• Laparoscopic/Open adhesiolysis
• Return to theatre for repair of fascial dehiscence
• Any reoperation/return to theatre meeting the criteria above is included

If multiple procedures (primary surgery or reoperation) are performed on different anatomical sites within the abdominal/pelvic cavity, the patient would be included if the major procedure is general surgical.

Exclusion Criteria:

• Not capable of giving informed consent after oral and written information
• Previously included in the trial
• Elective laparoscopy
• Diagnostic laparotomy/laparoscopy where no subsequent procedure is performed (NB, if no procedure is performed because of inoperable pathology, then include)
• Appendectomy +/- drainage of localized collection unless the procedure is incidental to a non-elective procedure on the GI tract
• Cholecystectomy +/- drainage of localized collection unless the procedure is incidental to a non-elective procedure on the GI tract (All surgery involving the appendix or gallbladder, including any surgery relating to complications such as abscess or bile leak is excluded)
• Non-elective hernia repair without bowel resection.
• Minor abdominal wound dehiscence unless this causes bowel complications requiring resection
• Ruptured ectopic pregnancy, or pelvic abscesses due to pelvic inflammatory disease
• Laparotomy/laparoscopy for pathology caused by blunt or penetrating trauma
• Laparotomy/laparoscopy for esophageal pathology
• Laparotomy/laparoscopy for pathology of the spleen, renal tract, kidneys, liver, gall bladder and biliary tree, pancreas or urinary tract