Clinical trial NCT02267031: The Role of Perioperative Ventilation (Gas Exchange) During Intrabdominal Surgery on Cognitive Function
Official title: The Role of Perioperative Ventilation (Gas Exchange) During Intrabdominal Surgery on Cognitive Function: a Randomized Clinical Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Response to Hyperoxia
Hypocapnia
Keywords: cognitive dysfunction
mechanical ventilation
hyperoxia
hypocapnia
Lead sponsor: Northern State Medical University
Sponsor class: OTHER
First posted: 2014-10-17
Enrollment: 109
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: Abdominal surgery commonly requires perioperative relaxation and therefore controlled mechanical ventilation. However, respiratory support can be associated with minor, yet clinically significant changes in blood gas content. The inadvertent hyperoxia (excessively high oxygen) and/or hypocapnia (excessively low carbon dioxide) can result in transient changes in cerebral blood flow and cognitive impair.

Detailed description: The moderate hyperventilation resulting in hypocapnia as well as hyperoxia are common features of mechanical ventilation during general anesthesia. While mild hyperventilation is routinely advocated in laparoscopic surgical interventions, increased FiO2 is set to reinforce safety of respiratory support. Hypocapnia may cause disturbances of cerebral blood flow due to narrowing of cerebral vessels and a decrease cerebral blood flow. Hypocapnia is particularly injurious to the brain in premature infants. Factors that may predispose the immature brain to such injury include poorly developed vascular supply to vulnerable areas, antioxidant depletion by excitatory amino acids, and the lipopolysaccharide and cytokine effects that potentiate destruction of white matter. Data from neonates clearly suggest that severe hypocapnia after hyperventilation contribute to adverse neurologic outcomes. The use of high concentrations of oxygen can lead to a number of events such as the formation of harmful free radicals and activation of lipid peroxidation, resulting in secondary brain injury due to hyperoxia, particularly after suffering anoxia of the brain in resuscitated victims of sudden cardiac arrest. It is recommended to use the fraction of oxygen to maintain saturation at the level of 94-98% when performing cardiopulmonary resuscitation (CPR), due to the risk of reperfusion injury. These disturbances of gas exchange, yet transient can interfere in cerebral blood flow and therefore mental functions.

The primary aim of this study was the assessment of the impact of intraoperative gas exchange (hypocapnia, hyperoxia and their combinations) on the state of higher nervous activity

Eligibility criteria: Inclusion Criteria:

* Informed consent
* Age \> 18 years and below 80 yrs
* Elective abdominal endoscopic intervention

Exclusion Criteria:

* Known cerebral disorder, incl. traumatic injury and severe vascular impairment
* Known psychiatric illness
* Severe drug or alcohol abuse
* Resent stroke (during last 6 months)
* Pregnancy
* Within the 30 days prior to this study, either entry into any other randomized therapeutic study of an agent not licensed for the intended use or administration of any other investigational agent for the treatment of ALI. Patients must not participate in such studies for at least 30 days after enrolment into this study.

Primary outcomes:
measure: Cognitive function
timeFrame: 36 hrs
Secondary outcomes:
measure: Psychological Changes
timeFrame: 6 months
measure: Pain perception
timeFrame: 6 hrs
measure: Pain perception
timeFrame: 36 hrs
Other outcomes:
Locations:
city: Arkhangelsk
country: Russian Federation
facility: City hospital # 1 / Northern State Medical University,
Study officials:
affiliation: Northern State Medical University
name: Mikhail Y. Kirov, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: