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Cognitive Effects of Inhalational Versus Intravenous General Anesthesia in the Elderly

Does Inhalational Anesthesia Accelerate Postoperative Cognitive Decline?

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00788008
Enrollment
200
Registered
2008-11-10
Start date
2008-11-30
Completion date
2013-12-31
Last updated
2015-03-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cervical Spondylosis, Hip Osteoarthritis, Knee Osteoarthritis, Lumbar Spondylosis

Keywords

spinal, joint

Brief summary

The purpose of this research is to determine if post-operative cognition will be better if the general anesthesia for surgery is done with an inhaled (gas through a breathing tube) or intravenous (medicine injected in the IV) general anesthetic technique.

Detailed description

A prospective randomized pre-test post-test design will be used. After obtaining informed consent, patients will be randomized to either: 1) Inhalational anesthesia with isoflurane or 2) Total intravenous anesthesia(TIVA) with propofol. Randomization will be stratified by surgical type so that this variable is equally distributed between the treatment groups. All patients will be maintained at a standard depth of anesthesia (40-60) using a Bispectral Index (BIS®) monitor. Normocarbia will be maintained in the operating room using capnography monitoring. Normothermia will be maintained throughout the procedure. The anesthesia team providing care for these patients will be able to choose the premedication and muscle relaxant for the anesthetic technique. Patient controlled anesthesia or regional anesthetic techniques may be used for post-operative analgesia at the discretion of the anesthesia team providing care for these patients. Anesthesia will be induced with intravenous propofol and fentanyl in all patients, unless contraindicated. Patients will be mechanically ventilated with air/oxygen. Temperature will be maintained \> 35º C and ventilation will be adjusted to maintain end-tidal carbon dioxide (CO2) at 35 ± 5 mmHg. Mean arterial pressure will be maintained ≥ 75% of baseline or ≥ 60 mmHg, whichever is greater, in both groups. After induction of anesthesia, the maintenance anesthesia will consist of either: 1. Inhalational anesthesia group - isoflurane will be used for maintenance of anesthesia. Intravenous fentanyl and/or remifentanil will be used for supplementary analgesia. These agents will be administered to maintain a normal depth of anesthesia using the BIS® monitor and traditional signs of anesthetic depth. 2. TIVA group - propofol and opioid infusions (fentanyl or remifentanil) will be used for the maintenance of anesthesia. The infusions will be adjusted to maintain a normal depth of anesthesia using the BIS® monitor along with traditional signs of anesthetic depth. All subjects will undergo pre-operative neurocognitive testing within two weeks of their surgery, and at 3 months post-surgery. The persistence versus resolution of cognitive deficits over time will be determined with a 1 year post-surgical follow-up assessment. Pre- to post-test change scores will be compared across groups on primary and secondary outcome variables (see below) while controlling for relevant demographic variables (age, education, sex).

Interventions

DRUGinhalation anesthesia with isoflurane vs. TIVA with propofol

variable depending upon patient

Sponsors

US Department of Veterans Affairs
CollaboratorFED
Duke University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
65 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* patients (aged 65 years or older) scheduled for elective spine or major joint replacement (total hip or total knee arthroplasty) at Duke University Medical Center or the Durham VA Medical Center

Exclusion criteria

* not fluent in English and able to comprehend the English language * have severe visual or auditory handicaps * Carry a diagnosis of dementia or score \< 18 on the Mini-Mental State Examination (MMSE) as calculated from the Modified Mini-Mental State (3MS) (see D4 below) * have allergies to eggs, propofol, isoflurane, fentanyl, remifentanil, or pregabalin

Design outcomes

Primary

MeasureTime frameDescription
Change in Neurocognitive Performance (Z-score)3 months post operativelyMean change on composite scores (z-score) for memory and executive function measures. Memory measures: Hopkins Verbal Learning Test-Revised and the Brief Visuospatial Memory Test-Revised. Executive function measures: the Trail Making Test (Army, 1944), Digit-symbol substitution and Symbol Search subtests of the Processing Speed Index of the Wechsler Adult Intelligence Scale-III (WAIS-III; Wechsler, 1997) and the Controlled Oral Word Association subtest of the Multilingual Aphasia Examination. The outcomes were constructed as summed z-score composites. They are scaled as standard deviations. Thus, a score of 0 was central on each composite, and 95% of the scores would fall within -2.0 and +2.0. While there is no minimum or maximum value is rare for any score (\<1%) to fall outside the -3.0 to +3.0 range. Higher scores (and thus positive change value) indicate an improvement of function.

Countries

United States

Participant flow

Pre-assignment details

200 patients were consented. One person dropped out prior to baseline testing.

Participants by arm

ArmCount
Isoflurane
Inhalational anesthesia with isoflurane
98
Propofol
Total intravenous anesthesia with propofol
101
Total199

Baseline characteristics

CharacteristicIsofluranePropofolTotal
Age, Continuous73.38 years73.13 years73.25 years
Region of Enrollment
United States
98 participants101 participants199 participants
Sex: Female, Male
Female
32 Participants39 Participants71 Participants
Sex: Female, Male
Male
66 Participants62 Participants128 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
0 / 980 / 101
serious
Total, serious adverse events
0 / 980 / 101

Outcome results

Primary

Change in Neurocognitive Performance (Z-score)

Mean change on composite scores (z-score) for memory and executive function measures. Memory measures: Hopkins Verbal Learning Test-Revised and the Brief Visuospatial Memory Test-Revised. Executive function measures: the Trail Making Test (Army, 1944), Digit-symbol substitution and Symbol Search subtests of the Processing Speed Index of the Wechsler Adult Intelligence Scale-III (WAIS-III; Wechsler, 1997) and the Controlled Oral Word Association subtest of the Multilingual Aphasia Examination. The outcomes were constructed as summed z-score composites. They are scaled as standard deviations. Thus, a score of 0 was central on each composite, and 95% of the scores would fall within -2.0 and +2.0. While there is no minimum or maximum value is rare for any score (\<1%) to fall outside the -3.0 to +3.0 range. Higher scores (and thus positive change value) indicate an improvement of function.

Time frame: 3 months post operatively

ArmMeasureGroupValue (MEAN)
IsofluraneChange in Neurocognitive Performance (Z-score)Executive Function measures-.42 z score
IsofluraneChange in Neurocognitive Performance (Z-score)Memory measures.09 z score
PropofolChange in Neurocognitive Performance (Z-score)Memory measures-.20 z score
PropofolChange in Neurocognitive Performance (Z-score)Executive Function measures.01 z score

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026