Ventilation Strategies, Anesthetic Techniques and Cerebral Oxygenation in the Beach Chair Position

NCT ID: NCT01535274

Last Updated: 2022-04-06

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 67 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2012-09-30
• Study Completion Date: 2014-09-30

Brief Summary

The seated or "beach chair" position during surgery and general anesthesia decreases brain oxygen levels and can result in stroke. As such, poor neurological outcome following beach chair positioning is a growing concern. In the proposed study the investigators test the hypothesis that changes in ventilation strategy and anesthetic technique can affect cerebral oxygenation in anesthetized patients in the beach chair position.

Detailed Description

This is a prospective cohort study with randomized nested design. Patients presenting for shoulder surgery will be randomized to receive desflurane or total intravenous anesthesia with propofol. Regional cerebral oxygenation will be measured using the INVOS 5100C monitor (Covidien, Boulder, CO). Depth of anesthesia will be maintained within a Bispectral Index range of 40-60. Following positioning, inspired oxygen fraction and minute ventilation will be sequentially adjusted. At each set point, regional cerebral oxygenation will be recorded and venous blood gas analysis performed. Statistical analysis will be repeated measures analysis of variance in which ventilation strategy is the within-subjects factor and anesthetic technique is the between-subjects factor; post hoc Tukey's correction will be used for multiple comparisons. If simple maneuvers of ventilation and anesthetic technique can prevent low brain oxygen levels, patient outcome may be improved.

Conditions

Stroke

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

Desflurane

Patients will receive general anesthesia with desflurane. Both arms have rSO2 measured and undergo identical changes in ventilation strategy.

Group Type: EXPERIMENTAL

Inspired oxygen fraction / end tidal carbon dioxide

Intervention Type: OTHER

Following induction of anesthesia, FIO2 and minute ventilation will be sequentially adjusted to achieve:

1. FIO2 30% (70% nitrogen), PETCO2 30mmHg - supine position.

2. FIO2 30% (70% nitrogen), PETCO2 30mmHg - beach chair position.

3. FIO2 100%, PETCO2 30mmHg - beach chair position.

4. FIO2 100%, PETCO2 45mmHg - beach chair position.

5. FIO2 30% (70% nitrogen), PETCO2 30mmHg - beach chair position.

Propofol

Patients will receive total intravenous general anesthesia (TIVA) with propofol. Both have rSO2 measured and undergo identical changes in ventilation strategy.

Group Type: EXPERIMENTAL

Inspired oxygen fraction / end tidal carbon dioxide

Intervention Type: OTHER

Following induction of anesthesia, FIO2 and minute ventilation will be sequentially adjusted to achieve:

1. FIO2 30% (70% nitrogen), PETCO2 30mmHg - supine position.

2. FIO2 30% (70% nitrogen), PETCO2 30mmHg - beach chair position.

3. FIO2 100%, PETCO2 30mmHg - beach chair position.

4. FIO2 100%, PETCO2 45mmHg - beach chair position.

5. FIO2 30% (70% nitrogen), PETCO2 30mmHg - beach chair position.

Interventions

Inspired oxygen fraction / end tidal carbon dioxide

Following induction of anesthesia, FIO2 and minute ventilation will be sequentially adjusted to achieve:

1. FIO2 30% (70% nitrogen), PETCO2 30mmHg - supine position.

2. FIO2 30% (70% nitrogen), PETCO2 30mmHg - beach chair position.

3. FIO2 100%, PETCO2 30mmHg - beach chair position.

4. FIO2 100%, PETCO2 45mmHg - beach chair position.

5. FIO2 30% (70% nitrogen), PETCO2 30mmHg - beach chair position.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• scheduled for elective arthroscopic shoulder surgery in the beach chair position under general anesthesia with supplemental interscalene block

Exclusion Criteria

• refusal to give consent
• ineligible for interscalene block
• history of cardiovascular disease
• history of cerebrovascular disease
• hypertension
• respiratory failure
• non-English speaker

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 85 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Michigan

OTHER

Sponsor Role: lead

Responsible Party

Paul Picton

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Paul Picton, MD

Role: PRINCIPAL_INVESTIGATOR

University of Michigan

Locations

University of Michigan

Ann Arbor, Michigan, United States

Countries

United States

References

Picton P, Dering A, Miller B, Shanks A, Mashour GA. The influence of basic ventilation strategies and anesthetic techniques on cerebral oxygenation in the beach chair position: study protocol. BMC Anesthesiol. 2012 Sep 20;12:23. doi: 10.1186/1471-2253-12-23.

Reference Type: DERIVED

PMID: 22994896 (View on PubMed)

Other Identifiers

HUM00049747

Identifier Type: -

Identifier Source: org_study_id