Clinical trial NCT02933749: Effects of the Prone and the Sitting Positions on the Brain Oxygenation in Posterior Fossa Surgery
Official title: Effects of the Prone and the Sitting Positions on the Brain Oxygenation in Posterior Fossa Surgery
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Infratentorial Neoplasms
Lead sponsor: Istanbul University
Sponsor class: OTHER
First posted: 2016-10-14
Enrollment: 62
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: FACTORIAL
Primary purpose: DIAGNOSTIC

Brief summary: The sitting or prone positions are used for posterior fossa surgery. Although the sitting position may cause hemodynamic instability, venous air embolism, it also provides optimum access to midline lesions, decreases intracranial pressure. The sitting position has not been only used in neurosurgery, it has been also used in the shoulder surgery. The sitting position related hypotension may reduce the cerebral perfusion pressure, therefore may cause cerebral ischemia. The sitting position related cerebral ischemia has been shown in the shoulder surgery. The non invasive cerebral oxymetry (INVOS-Covidien) has been used to measure cerebral oxygen saturation. Some studies has been done to investigate whether the sitting position cause cerebral desaturation or not in the shoulder surgery by non invasive cerebral oxymetry. The study results are controversial.

It has been investigated that the effect of the prone position on the cerebral oxygenation in the spine surgery and the investigators found that the prone position may increase cerebral oxygenation.

However, all studies have been done in patients without intracranial pathology. We speculate that due to the sitting position reduces the intracranial pressure, it may improve the cerebral oxygenation in the patients have intracranial pathology. Therefore we will compare the sitting and the prone positions effects on the cerebral oxygenation in patients undergoing posterior fossa tumour surgery by non invasive cerebral oxymetry.

Method: 62 patients have posterior fossa tumour will include the study. Patients will divide to 2 groups according to the surgical position, the prone (n=31) or the sitting (n=31). Patients heart rate, mean blood pressure (MAP), cerebral oxygen saturation (SctO2), peripheral oxygen saturation (SpO2), BIS values will record before the induction of anesthesia. Five minutes after the standard anesthesia induction all values will record and it will accept as a baseline. After that all these parameters will record in each 3 minutes until the beginning of surgery. Mean while, more than 5 % reduction in SctO2 and more than 20 % reduction in SctO2 and/or MAP will record. As well as, if the SctO2 reduces than 55 and 60 %, it will record.

Detailed description: The sitting or prone positions are used for posterior fossa surgery. Although the sitting position may cause significant complications such as including hemodynamic instability, venous air embolism, paradoxical air embolism (PAE), pneumocephalus, peripheral neuropathy, quadriplegia and macroglossia, it also provides optimum access to midline lesions in posterior fossa and cervical spine, improves blood and cerebral spinal fluid drainage, decreases intracranial pressure, lowers airway pressure, and improves access to the endotracheal tube and ability to observe the face for signs of cranial nerves stimulations. The sitting position has not been only used in neurosurgery, it has been also used in the shoulder surgery. The sitting position related hypotension may reduce the cerebral perfusion pressure, therefore may cause cerebral ischemia. The sitting position related cerebral ischemia has been shown in the shoulder surgery.

The non invasive cerebral oxymetry (INVOS-Covidien) has been used to measure cerebral oxygen saturation. Some studies has been done to investigate whether the sitting position cause cerebral desaturation or not in the shoulder surgery by non invasive cerebral oxymetry. The study results are controversial.

It has been investigated that the effect of the prone position on the cerebral oxygenation in the spine surgery and the investigators found that the prone position may increase cerebral oxygenation.

However, all studies have been done in patients without intracranial pathology. We speculate that due to the sitting position reduces the intracranial pressure, it may improve the cerebral oxygenation in the patients have intracranial pathology. Therefore we will compare the sitting and the prone positions effects on the cerebral oxygenation in patients undergoing posterior fossa tumour surgery by non invasive cerebral oxymetry.

Method: 62 patients have posterior fossa tumour will include the study. Patients will divide to 2 groups according to the surgical position, the prone (n=31) or the sitting (n=31). Patients heart rate, mean blood pressure (MAP), cerebral oxygen saturation (SctO2), peripheral oxygen saturation (SpO2), BIS values will record before the induction of anesthesia. Five minutes after the standard anesthesia induction all values will record and it will accept as a baseline. After that all these parameters will record in each 3 minutes until the beginning of surgery. Mean while, more than 5 % reduction in SctO2 and more than 20 % reduction in SctO2 and/or MAP will record. As well as, if the SctO2 reduces than 55 and 60 %, it will record.

Eligibility criteria: Inclusion Criteria:

* Diagnosis of infratentoril neoplasms

Exclusion Criteria: Stroke

* Diabetes mellitus
* Chronic obstructive pulmonary disease
* Anemia

Primary outcomes:
measure: Cerebral oxygen saturation
timeFrame: Change from baseline cerebral oxygen saturation up to skin incision
Secondary outcomes:
Other outcomes:
Locations:
city: Istanbul
country: Turkey
facility: Ozlem Korkmaz Dilmen
Study officials:
affiliation: Istanbul University - Cerrahpasa
name: Ozlem Korkmaz Dilmen
role: STUDY_DIRECTOR
References:
citation: Dilmen OK, Akcil EF, Tureci E, Tunali Y, Bahar M, Tanriverdi T, Aydin S, Yentur E. Neurosurgery in the sitting position: retrospective analysis of 692 adult and pediatric cases. Turk Neurosurg. 2011;21(4):634-40.
citation: Pohl A, Cullen DJ. Cerebral ischemia during shoulder surgery in the upright position: a case series. J Clin Anesth. 2005 Sep;17(6):463-9. doi: 10.1016/j.jclinane.2004.09.012.
citation: Murphy GS, Szokol JW, Marymont JH, Greenberg SB, Avram MJ, Vender JS, Vaughn J, Nisman M. Cerebral oxygen desaturation events assessed by near-infrared spectroscopy during shoulder arthroscopy in the beach chair and lateral decubitus positions. Anesth Analg. 2010 Aug;111(2):496-505. doi: 10.1213/ANE.0b013e3181e33bd9. Epub 2010 May 27.