Pre-emptive Hemodynamic Optimization of High Risk Patients Undergoing Elective Major Surgical Procedures

• Duration of mechanical ventilation. Duration of ICU and hospital stay. Infection Renal function. Bowel movement. Oral intake. 3-month period Quality of life. [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
  

• As in the primary [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
  

This is a randomized, prospective study which will include a total of 200 patients who are scheduled to undergo major elective surgery with an anticipated blood loss of ≥ 500 ml. The research participants will be randomly assigned to a control group (n=100) that will receive the standard of care for intraoperative management by the anesthesia. Minimal resuscitation standards include a mean arterial pressure > 65 mm Hg, SpO2 > 90% and evidence of end-organ perfusion (i.e. mentation prior to induction of anesthesia, urine output > 20 ml/hr) and absence of tachycardia (HR < 100/min). The protocol group (n=100) will, in addition, receive further resuscitation to achieve an increased oxygen delivery (DO2) to a targeted of 600 ml/min/m2. This approach is called goal-directed therapy. This target DO2 will be achieved via a treatment algorithm that includes intraoperative volume expansion and/or dobutamine infusion, guided by the LiDCO cardiovascular monitoring of stroke volume and cardiac output. All patients will also have non-invasive tissue O2 saturation (StO2) monitoring using the InSpectra probe on their hand. Patients in the protocol group will be subdivided to 2 subgroups. Group one subjects will be those patients that are directly admitted to the ICU following surgery and group two subjects will be those patients discharged to the PAR and then a regular hospital ward. All subjects will continue to receive goal directed therapy for as long as they are in the PAR or ICU or until 8 hours of post-operative time has elapsed. All participants will be followed daily during their hospital stay to assess the development of complications, length of stay and discharge status. All patients will receive phone interview at one and 3 months after the surgery to inquire about their quality of life since their surgery using the SF36 instrument. The total duration of participant's commitment to the study will be 3 months, during which their lab and clinical data will be recorded. Statistical analysis of the data will be performed at the conclusion of the study period by professional statistician to determine the difference in the outcome and morbidity and mortality between the two groups using multiple logistic regression and Cox proportional hazard scoring with primary outcome variables being length of stay, total complications, and mortality.