Machine Learning Modeling of Intraoperative Hemodynamic Predictors of Postoperative Outcomes

NCT04014010 | Completed

• 1 other identifier: 1024251
• Study Type: observational
• Target: 35,000
• Locations: 0 countries
• Sites: N/A

Brief Summary

With population aging and limited resources, strategies to improve outcomes after surgery are ever more important. There is a limited understanding of what ranges of hemodynamic variables under anesthesia are associated with better outcomes. This retrospective cohort study will analyze how hemodynamic variables during surgeries predict mortality, morbidity, Intensive Care Unit admission, length of hospital stay, and hospital readmission. The use of machine learning in a large, broad surgery population dataset could detect new relationships and strategies that may inform current practice, and generate ideas for future research.

Conditions

Perioperative/Postoperative Complications; Morbidity, Multiple; Surgery; Anesthesia; Death

Keywords

Perioperative; Anesthesia; Hemodynamics; Machine Learning; Non-cardiac Surgery

Outcome Measures

Primary Outcomes (1)

• Mortality

  All-cause postoperative mortality (yes/no)

  30 days after date of surgery

Secondary Outcomes (12)

• In-hospital Morbidity: Any

  30 days after date of surgery

• In-hospital Morbidity: Cardiac

  30 days after date of surgery

• In-hospital Morbidity: Respiratory

  30 days after date of surgery

• In-hospital Morbidity: Acute Kidney Injury

  30 days after date of surgery

• In-hospital Morbidity: Cerebrovascular

  30 days after date of surgery

Study Arms (1)

Cohort

Patients ages ≥ 45 receiving their index (i.e. first) non-cardiac surgery with an overnight stay at the Nova Scotia Health Authority Queen Elizabeth II (QEII) hospitals (Victoria General and Halifax Infirmary) Halifax, Canada, from January 1, 2013 to December 1, 2017 will be included. Patients under going cardiac surgery or deceased organ donation will be excluded. Patients without an electronic anesthetic record during surgery will also be excluded. Preliminary analysis of the intraoperative database estimates approximately 35,000 patients in this cohort.

Other: Blood pressure; Other: Heart rate; Other: Use of hemodynamic medications (i.e. special medications for blood pressure); Other: Oxygen saturation by pulse oximetry (SpO2); Other: End-tidal Carbon dioxide (EtCO2)

Interventions

Blood pressure OTHER

Systolic Blood Pressure (SBP) 1. Maximum change from preoperative SBP, in a) absolute change (mmHg), and b) relative change (%)(emergency and elective cases analyzed separately) 2. Cumulative duration (minutes) \>=20% below preoperative SBP 3. Longest single episode (minutes) below a) 80, b) 90, and c)100 mmHg 4. Cumulative duration (minutes) below a) 80, b) 90, and c)100 mmHg Mean Arterial Pressure (MAP) 1. Maximum change from preoperative MAP, in a) absolute change (mmHg), and b) relative change (%) (emergency and elective cases analyzed separately) 2. Cumulative duration (minutes) \>=20% below preoperative MAP 3. Longest single episode (minutes) below a) 60, b) 65, c) 70, and d) 80mmHg 4. Cumulative duration (minutes) below a) 60, b) 65, c) 70, and d) 80mmHg

Cohort

Heart rate OTHER

1. Maximum change (beats per minute, BPM) from preoperative heart rate (positive and negative) 2. Relative change (%) from preoperative heart rate (positive and negative) 3. Maximum pulse variation (maximum heart rate minus minimum heart rate) 4. Longest single episode (minutes) a) below 60, and b) above 100BPM 5. Cumulative duration (minutes) a) below 60, and b) above 100BPM

Cohort

Use of hemodynamic medications (i.e. special medications for blood pressure) OTHER

1. Vasopressor/inotrope use (yes vs. no): phenylephrine, norepinephrine, epinephrine, vasopressin, dobutamine, or milrinone 2. Infusion of any vasopressor/inotropes above (yes vs. no) (identified by unit of weight over time) 3. Phenylephrine/ephedrine bolus (yes vs. no) (identified by unit of weight only) 4. Vasodilator use (yes vs. no): labetalol, esmolol, nitroglycerin, nitroprusside 5. Infusion of any vasodilator above (yes vs. no) (identified by unit of weight over time)

Cohort

Oxygen saturation by pulse oximetry (SpO2) OTHER

1. Longest single episode (minutes) below a) 88, and b) 90% 2. Cumulative duration (minutes) below a) 88, and b) 90%

Cohort

End-tidal Carbon dioxide (EtCO2) OTHER

1. Longest single episode (minutes) a) below 30, and b) above 45mmHg 2. Cumulative duration (minutes) a) below 30, and b) above 45mmHg

Cohort

Eligibility Criteria

• Age: 45 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

For data analysis in summer 2019, we have access to mortality data up to December 31, 2017. We chose December 1, 2017, as the last surgery date to be included, to allow for a complete data set 30 days after surgery. January 1, 2013 was chosen to obtain a study period of 5 years.

You may qualify if:

• All patients ages ≥ 45 receiving their index (i.e. first) non-cardiac surgery with an overnight stay at the Nova Scotia Health Authority Queen Elizabeth II (QEII) hospitals (Victoria General and Halifax Infirmary) Halifax, Canada, from January 1, 2013 to December 1, 2017.
• For patients who had multiple surgeries, only the first non-cardiac surgery with an overnight stay at QEII will be included to avoid confounding from previous surgical admissions (i.e. one surgical admission per patient).

You may not qualify if:

• No intraoperative anesthetic records
• Cardiac surgery patients
• Deceased organ donation

Sponsors & Collaborators

• Janny Xue Chen Ke: lead
• Dalhousie University: collaborator
• Harvard University: collaborator
• University of Toronto: collaborator
• University of Ottawa: collaborator

Related Publications (1)

• Ke JXC, McIsaac DI, George RB, Branco P, Cook EF, Beattie WS, Urquhart R, MacDonald DB. Postoperative mortality risk prediction that incorporates intraoperative vital signs: development and internal validation in a historical cohort. Can J Anaesth. 2022 Sep;69(9):1086-1098. doi: 10.1007/s12630-022-02287-0. Epub 2022 Aug 22.

  PMID: 35996071 DERIVED

MeSH Terms

Conditions

Postoperative Complications; Death

Interventions

Blood Pressure; Heart Rate; Oxygen Saturation

Condition Hierarchy (Ancestors)

Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Vital Signs; Physical Examination; Diagnostic Techniques and Procedures; Diagnosis; Hemodynamics; Cardiovascular Physiological Phenomena; Circulatory and Respiratory Physiological Phenomena; Metabolism

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Anesthesiology Resident

Study Record Dates

• First Submitted: July 7, 2019
• First Posted: July 10, 2019
• Study Start: January 1, 2013
• Primary Completion: December 31, 2017
• Study Completion: December 31, 2017
• Last Updated: June 30, 2020

Record last verified: 2020-06

Data Sharing

• IPD Sharing: Will not share