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Effect of Different Positive End Expiratory Pressures on Regional Cerebral Oxygen Saturation

Not Applicable
Completed
Conditions
Regional Cerebral Oxygen Saturation
Interventions
Other: 5 cmH2O Positive end-expiratory pressure (PEEP)
Other: 10 cmH2O Positive end-expiratory pressure (PEEP)
Registration Number
NCT05961917
Lead Sponsor
Bozyaka Training and Research Hospital
Brief Summary

The goal of this prospective single-blind randomized clinical trial is to compare the effect of two different positive end expiratory pressure (PEEP) levels on regional cerebral oxygen saturation in patients scheduled for craniotomy due to supratentorial masses.

The main question it aims to answer is that how high PEEP level effects the regional cerebral oxygen saturation in patients with high intracranial pressure due to mass effect. Patients will be divided into two groups as Group low PEEP (5 cmH2O) and Group high PEEP (10 cmH2O). Researchers will compare the changes of regional cerebral oxygen saturations between two groups by near infra-red spectroscopy.

Detailed Description

In this prospective single-blind study, American Society of Anesthesiologists physical status classification system (ASA) I and II patients aged older than 18 years undergoing craniotomy will be enrolled for the study. Patients will be divided into two groups with computer-based randomization technique. Written and verbal approval will be taken from all patients. Premedication will not be used. Patients will be monitorized by standard non-invasive monitorization (electrocardiography, non-invasive blood pressure measurement, peripheral oxygen saturation) in the operating room. Cerebral/somatic oximeter, near infra-red spectroscopy (NIRS) sensor will be placed on the frontotemporal area and regional cerebral oxygen saturation will be monitorized continuously. Remifentanil infusion with a dose of 0.25 mcg/kg/min will be started two minutes before the induction. After preoxygenation with 6 L/min oxygen for 5 minutes, general anesthesia induction for patients in both groups will be held with intravenous 2 mg/kg propofol. Rocuronium bromide (0.6 mg/kg) will be used for muscle relaxation. Endotracheal intubation will be performed. Controlled mechanical ventilation will be used during the surgery. Invasive arterial blood pressure monitorization will be done and a central venous catheter will be placed in both groups.

In group low PEEP, the patients' settings of mechanical ventilation will be as tidal volume 6-8 mL/kg, inspired oxygen fraction (FiO2) 0.4, PEEP 5 cmH2O. Frequency will be set according to the end tidal carbon dioxide pressure (ETCO2) where it will be 30-32 mmHg.

In group high PEEP, the patients' settings of mechanical ventilation will be as tidal volume 6-8 mL/kg, inspired oxygen fraction (FiO2) 0.4, PEEP 10 cmH2O. Frequency will be set according to the end tidal carbon dioxide pressure (ETCO2) where it will be 30-32 mmHg.

Remifentanil with a dose of 0.05-2 mcg kg/min and propofol with a dose of 50-200 mcg/kg/min will be infused for general anesthesia maintenance in both groups. Dose of remifentanil infusion will be changed according to the blood pressure. If the mean arterial blood pressure and/or heart rate will decrease to 20% of the baseline mean arterial blood pressure and heart rate, the infusion dose will be lowered. If this decrease in heart rate will be over 25%, intravenous 0.5 mg atropin will be administered. If the mean arterial blood pressure will be under 55 mmHg, intravenous 5 mg ephedrine will be administered. If the mean arterial blood pressure will continue to decrease, PEEP will be lowered. If the peripheral oxygen saturation will be under 92%, the inspired oxygen fraction or PEEP will be increased. In these conditions, the patient will be out of study.

1 gr paracetamol will be given intravenously for pain relief. Sugammadex will be used with a dose of 4 mg/kg for extubation.

Regional cerebral oxygen saturation measures will be recorded nine (9) times during the study; pre-induction (period 1), post-induction (period 2), skull pinning (period 3), before dura opening (period 4), after dura opening (period 5), surgical resection of the mass (period 6), dura closure (period 7), end of the surgery (period 8) and end of anesthesia (period 9).

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
64
Inclusion Criteria
  • Older than 18 years
  • American Society of Anesthesiologists physical status classification system (ASA) I and II
  • Patients scheduled for elective craniotomy
  • Patients with supratentorial mass
Exclusion Criteria
  • Hemoglobin concentration lower than 9 mg/dL
  • Uncontrolled hypertension
  • Congestive heart failure
  • Severe chronic obstructive lung disease
  • Cerebrovascular disease
  • Pulmonary edema
  • History of carotis surgery or stenosis of carotid artery
  • Unstable hemodynamics
  • Pregnancy
  • Skin reaction to the NIRS sensor
  • Patient's refusal

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Group low PEEP5 cmH2O Positive end-expiratory pressure (PEEP)Positive end-expiratory pressure will be set at 5 cmH2O during controlled mechanical ventilation.
Group high PEEP10 cmH2O Positive end-expiratory pressure (PEEP)Positive end-expiratory pressure will be set at 10 cmH2O during controlled mechanical ventilation.
Primary Outcome Measures
NameTimeMethod
regional cerebral oxygen saturation (SrO2) period 2Up to 5 minutes after anethesia induction

The measurement of regional cerebral oxygen saturation after anesthesia induction

regional cerebral oxygen saturation (SrO2) period 1Pre-induction

The measurement of regional cerebral oxygen saturation before anesthesia induction

regional cerebral oxygen saturation (SrO2) period 8Within 5 minutes after the surgery

The measurement of regional cerebral oxygen saturation at the end of surgery

regional cerebral oxygen saturation (SrO2) period 3From skull-pinning to final head position

The measurement of regional cerebral oxygen saturation during skull pinning

regional cerebral oxygen saturation (SrO2) period 4Just before dura opening

The measurement of regional cerebral oxygen saturation before dura opening

regional cerebral oxygen saturation (SrO2) period 5Up to 5 minutes of dura opening

The measurement of regional cerebral oxygen saturation after dura opening

regional cerebral oxygen saturation (SrO2) period 7Up to 5 minutes of dura closure

The measurement of regional cerebral oxygen saturation after dura closure

regional cerebral oxygen saturation (SrO2) period 6During surgical resection

The measurement of regional cerebral oxygen saturation during surgical resection of the mass

regional cerebral oxygen saturation (SrO2) period 9Within 5 minutes after end of anesthesia

The measurement of regional cerebral oxygen saturation at the end of anesthesia

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

University of Health Sciences İzmir Bozyaka Education and Research Hospital

🇹🇷

İzmir, Bozyaka, Turkey

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