Oxygen Extraction and Delivery in Elderly During Major Surgery

Exploring New Grounds in Physiology of the Elderly- Oxygen Extraction and Delivery During Anaesthesia and Major Surgery

This clinical observational study investigates perioperative oxygen consumption and delivery in elderly patients undergoing major surgery. The primary objectives are to characterise the perioperative oxygen delivery, consumption and potential markers of oxygen debt. Secondary objective is to estimate the correlation between oxygen delivery/consumption and postoperative outcomes to guide the design of a future trial.

Study Overview

• Status: Completed
• Conditions: Postoperative Complications; Surgery; Peroperative Complication; Impaired Oxygen Delivery
• Intervention / Treatment: Other: General anaesthesia and major surgery

Detailed Description

Background Intra- and postoperative fluid therapy aims to achieve or maintain pre-specified thresholds of oxygen delivery/blood flow which can be accomplished by use of fluids with or without inotropic drugs. The used thresholds of oxygen delivery were suggested over 40 years ago, in considerably younger patients compared to the current patients. Update of the characteristics of perioperative oxygen delivery and consumption is reasonable in modern clinical settings.

Primary outcome:

relative changes of oxygen consumption induced by anaesthesia

Secondary outcomes:

relative changes of oxygen consumption and delivery during surgery and postoperatively, oxygen extraction ratio (measured and estimated), potential markers of oxygen debt frequency of in-hospital postoperative complications, mortality (30 Days)

Population:

Men and women ≥65 years undergoing major/complex surgical procedures, when intra-operative cardiovascular monitoring is justified according to clinical decision.

Intervention: no study related intervention, general anaesthesia and surgery according to clinical routine

Blinding: no blinding

Study size:

Pilot study 1: feasibility assessment of study protocol of intra-operative measurements (n= max 10) Pilot study 2: feasibility assessment of study protocol of postoperative measurements (n= max 10) Main study: 60 subjects (20+´40) Planned analysis of oxygen consumption after 20 monitored subjects

Study duration:

Duration of haemodynamic monitoring 24-36 hours Duration of observation of clinical outcomes: 7-10 days, mortality at 30 days postop.

Investigational events:

monitoring of oxygen consumption and delivery monitoring of postoperative clinical outcomes monitoring of markers of tissue injury

Assessments, Procedures and Schedule of Investigational Events:

Subjects are identified by the operation planning list and assessed for eligibility. The study information will be given verbal during the first hospital visit. Subjects who give written informed consent will be included in the study.

Measurements:

oxygen consumption by indirect calorimetry via face mask (in awake state) and via expiratory extension tube of anaesthesia machine (unconscious state) cardiac output monitoring via arterial line (LiDCO) blood samples: arterial and venous blood gase samples, Troponin-T urine samples: N-gal

Clinical outcomes:

Data collection from medical records on postoperative complications using the POMS (postoperative morbidity survey) screening survey at days 3,7 and 10. Postoperative mortality at day 30.

• Study Type: Observational
• Enrollment (Actual): 20

Contacts and Locations

Study Locations

• Sweden
  • Stockholm, Sweden, 141 86
    • Karolinska University Hospital Huddinge

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years and older (OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Men and women ≥65 years undergoing major/complex surgical procedures at the Karolinska University Hospital in Huddinge, Stockholm

Description

Inclusion Criteria:

1. Men and women aged ≥65 years
2. Major/complex surgery (BUPA AXA classification of surgical severity)
3. Central and arterial venous catheterization for hemodynamic monitoring.
4. Written informed consent
5. Available research team for the measurements If two subjects are eligible the elder one will be chosen. If there are two subjects eligible of different gender and almost the same age, the subject with a gender that is underrepresented by two or more will be chosen. This is consistent with the purpose of including subjects with as high age as possible without interfering with recruitment.

Exclusion Criteria

1. Concomitant medication with Lithium (interferes with calibration of the LiDCO monitor)
2. Weight≤ 40 kg.
3. Not possible to establish arterial or central venous line.
4. Planned postoperative care at high-dependency unit (POP/IMA) <12hrs.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
oxygen consumption	change of oxygen consumption after anaesthesia induction	prior to and 15 minutes after anaesthesia induction

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
oxygen consumption	changes of oxygen consumption during surgery and postoperative recovery	perioperatively 0-36hrs
oxygen extraction ratio	ratio between oxygen consumption and oxygen delivery	perioperatively 0-36hrs
oxygen extraction ratio: estimated and measured	ratio between oxygen consumption and oxygen delivery estimated from blood gases and measured by indirect calorimetry and cardiac output monitoring	perioperatively 0-36hrs
C(v-a)pCO2/C(a-v)O2	Ratio: venoarterial pCO2 difference/arterio-venous oxygen content difference	perioperatively 0-36hrs
postoperative complications	postoperative complications described by Postoperative Morbidity Survey (8)	postoperative days 3,5 and 10
mortality	postoperative mortality	postoperative days 30

Collaborators and Investigators

• Sponsor: Karolinska Institutet
• Investigators: Study Director: Erzsebet Bartha, MD PhD, Karolinska University Hospital Huddinge, Stockholm, Sweden; Principal Investigator: Julia Jakobsson, MD, Karolinska University Hospital Huddinge, Stockholm, Sweden

Publications and helpful links

General Publications

• Jakobsson J, Noren C, Hagel E, Kalman S, Bartha E. Peri-operative oxygen consumption revisited: An observational study in elderly patients undergoing major abdominal surgery. Eur J Anaesthesiol. 2021 Jan;38(1):4-12. doi: 10.1097/EJA.0000000000001302.

Study record dates

Study Major Dates

• Study Start (ACTUAL): November 27, 2017
• Primary Completion (ACTUAL): March 23, 2018
• Study Completion (ACTUAL): April 4, 2018

Study Registration Dates

• First Submitted: November 22, 2017
• First Submitted That Met QC Criteria: November 22, 2017
• First Posted (ACTUAL): November 28, 2017

Study Record Updates

• Last Update Posted (ACTUAL): June 30, 2022
• Last Update Submitted That Met QC Criteria: June 28, 2022
• Last Verified: June 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications; Intraoperative Complications; Physiological Effects of Drugs; Central Nervous System Depressants; Anesthetics
• Other Study ID Numbers: K2017-0373; 4-500/2017 (OTHER: Karolinska Institutet)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No