The Effect of Ventilation on Cerebral Oxygenation in the Sitting Position

NorthShore University HealthSystem

Status: Completed

Conditions: Cerebral Ischemia

Treatments: Other: Normocapnic group; Other: Hypocapnic group

Study type: Interventional

Funder types: Other

Identifiers

NCT01546636

EH10-184

Details and patient eligibility

About

The aim of this clinical investigation is to determine the effect of intraoperative ventilation on cerebral oxygen saturation in patients undergoing arthroscopic shoulder surgery in the beach chair position (BCP)

Full description

Recent developments in near-infrared spectroscopy technology now permit rapid assessment of cerebral oxygenation (SctO2) using non-invasive probes. A high incidence cerebral desaturation events (CDE-defined as a decrease in SctO2 values below 20% of baseline measures or absolute SctO2 values ≤ 55 for ≥ 15 seconds) have been observed in previous investigation of patients undergoing shoulder surgery in BCP with hyperventilation. The investigators hypothesize that the incidence of CDE will be reduced in patients ventilated at normocapnic levels (end-tidal carbon dioxide values (ETCO2) of 40-42 mm Hg) when compared to subjects hyperventilated (ETCO2 of 30-32 mm Hg) in the operating room. Patients undergoing shoulder surgery in the BCP will be randomized to a hypocapnic group (ETCO2 of 30-32 mm Hg) or a normocapnic group (ETCO2 of 40-42 mm Hg). Cerebral oxygenation will be measured continuously throughout the procedure to assess perioperative SctO2 values and the incidence of CDE. The investigators previously observed an association between CDE in the operating room and postoperative nausea and vomiting. Therefore, the effect of ventilatory pattern and intraoperative SctO2 on clinical recovery will also be determined.

Enrollment: 70 patients

Sex: All

Ages: 18 to 90 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients presenting for elective shoulder arthroscopy under general anesthesia in the BCP.

Exclusion criteria

• Exclusion criteria include 1) history of pre-existing cerebrovascular disease or orthostatic hypotension 2) age < 18 years 3) American Society of Anesthesiologists Physical Status IV or V.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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70 participants in 2 patient groups, including a placebo group

Hypocapnic group

Placebo Comparator group

Description:

Patients will be ventilated to an ETCO2 of 30-32 mm Hg.

Treatment:

Other: Hypocapnic group

Normocapnic group

Active Comparator group

Description:

Patients will be ventilated to an ETCO2 of 40-42 mm Hg

Treatment:

Other: Normocapnic group