The investigators measured changes in cerebral oxygen saturation (rSO2) and MMSE scores after retrobulbar block performed with levobupivacaine and lidocaine in patients undergoing vitreoretinal surgery.A total of 66 patients over the age of 60 undergoing vitreoretinal surgery with a total duration of less than 1 hour were included in this prospective, double-blinded study. The patients were randomly divided into two groups: group L (5ml, 2% lidocaine) and group LB (5ml, 0.5% levobupivacaine). Bilateral rSO2 measurements were recorded before the retrobulbar block and at 1-5 minutes post-block, during the procedure, and at 10-40 minutes post-op. MMSE was performed preoperatively and postoperatively in order to evaluate short term cognitive function. Sensory and motor block durations, pain, akinesia and conjunctival feeling scores, patient-surgeon satisfaction, and complications were also recorded.
A total of 66 patients undergoing vitreoretinal surgery (total duration \< 60 minutes) using retrobulbar block, who were classified as category I-III according to the ASA (American Society of Anesthesiologists) Classification system, who were over the age of 60, and who had no cognitive dysfunction were included in the study. Exclusion criteria were as follows: contraindication for retrobulbar block, preoperative systolic blood pressure of 180 mmHg, diastolic blood pressure of above 100 mmHg, uncontrolled diabetes, body mass index ≥ 30 kg/m2, MMSE ≤ 24, advanced organ failure, or Hb \< 9gr/dl.The patients were randomly divided into two groups using a sealed-envelope method: Group L: Patients undergoing block with lidocaine (n = 33) Group LB: Patients undergoing block with levobupivacaine (n = 33) The patients did not undergo premedication in order to accommodate the postoperative MMSE evaluation. For intra-operative sedation, remifentanil (UltivaR, GlaxoSmithKline, Berntford, UK) was initiated as an infusion at a dose range of 0.05-0.1 mcg/kg/min. The mean arterial pressure and heart rate values were allowed to vary up to 20% of the preoperative values of the patients. For this purpose, the remifentanil infusion rate was increased or decreased at the determined dose interval. Retrobulbar block was performed with 5 ml of 2% lidocaine hydrochloride (AritmalR, Osel, Istanbul, Turkey) in Group L patients and 5ml of 0.5% levobupivacaine (ChirocaineR, Abbvie, Chicago, USA) in Group LB patients. The block was performed by the same practitioner (fourth year assistant of Ophthalmology Department) using inferotemporal approach as described by Sanderson using 27 gage disposable needles (Atkinson Retrobulbar NeedleR, Asico, USA). Sensory and motor block onset and end times and akinesia score were recorded. The mean arterial pressure (MAP), heart rate (HR), and oxygen saturation (SpO2) were recorded in the preoperative period, at minutes 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 intra-operatively, and at 10, 20, 30, and 40 minutes postoperatively in the recovery room. . The patients were transferred to the operating table for measurement of bilateral rSO2, and preoxygenation was performed for three minutes using 4 L/min 100% oxygen via nasal cannula. The basal oxygenation values were determined by taking the average of the last 30 s measurements. The rSO2 values were recorded at 1, 3, 5, 10, 15, 20, 25, 30th, 35, 40, 45, 50, 55, and 60 minutes after retrobulbar block, and at 10, 20, 30, and 40 minutes after the completion of the procedure. Cognitive functions were assessed by the same technician using MMSE in the preoperative period, 40 minutes postoperatively and at 7 days after the operation (short term).Surgeon satisfaction was queried at the end of the case and patient satisfaction was questioned at the end of day.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SUPPORTIVE_CARE
Masking
SINGLE
Enrollment
66
Retrobulbar block was performed with 5 ml of 2% lidocaine hydrochloride (AritmalR, Osel, Istanbul, Turkey) in Group L patients. The block was performed by the same practitioner (fourth year assistant of Ophthalmology Department) using inferotemporal approach as described by Sanderson using 27 gage disposable needles (Atkinson Retrobulbar NeedleR, Asico, USA)
and 5ml of 0.5% levobupivacaine (ChirocaineR, Abbvie, Chicago, USA) in Group LB patients. The block was performed by the same practitioner (fourth year assistant of Ophthalmology Department) using inferotemporal approach as described by Sanderson using 27 gage disposable needles (Atkinson Retrobulbar NeedleR, Asico, USA)
Ondokuz Mayis Universitesi
Samsun, Atakum, Turkey (Türkiye)
Cerebral oxygen saturation changes (rSO2)
The NIRS device probes (INVOS-3100AR; Somanetics Inc., Troy, MI, USA) were placed at least 2 cm above the eyebrows and 3 cm away from the mid-line of the forehead, on right and left, in accordance with the instructions of manufacturer.The patient's forehead was cleaned with acetone alcohol before the sensor pads were glued, and wrapped with a bandage so that the sensors were not affected by ambient light. The patients were transferred to the operating table for measurement of bilateral rSO2, and preoxygenation was performed for three minutes using 4 L/min 100% oxygen via nasal cannula.
Time frame: The rSO2 value changes were recorded from baseline up to 40 minutes after surgery
Cognitive function measurement
Cognitive functions were assessed by the same technician using the Mini Mental State Examination (MMSE) test.
Time frame: Cognitive functions were assessed from baseline up to 7 days after the surgery
Sensory block onset time by the conjunctival feeling score using the cotton contact test.
The sensory block onset time was recorded as the moment when the patient did not feel a piece of cotton touching the cornea. This time was measured by the conjunctival feeling score using the cotton contact test (0: normal, 1: less sensitive, 2: complete sensory loss). Score of 2 on the scale was considered as onset time for sensory block.
Time frame: The sensory block onset time was recorded at the beginning of surgery till the first 15 min
Sensory block end time by the conjunctival feeling score using the cotton contact test.
The time at which recovery of sensory block was recovered was measured by the conjunctival feeling score using the cotton contact test (0: normal, 1: less sensitive, 2: complete sensory loss). Score of 0 on the scale was considered as end time for sensory block.
Time frame: The sensory block end time was recorded at the end of surgery till the first 24 h
Motor block onset time by eye movements score.
The motor block onset time was recorded as the time that the patient's eye movements score was four or less. Eye movements score was measured over three points in each of the four quadrants as follows: 3, full eye movement and 0, no movement.
Time frame: The motor block onset time was recorded at the beginning of surgery till the first 15 min
Motor block end time by eye movements score.
The time at which recovery of motor block was recovered was measured by the eye movements score (three points in each of the four quadrants as follows: 3, full eye movement and 0, no movement). Score of 12 on the scale was considered as end time for motor block.
Time frame: The motor block end time was recorded at the end of surgery till the first 24 h
The akinesia score measurement
The akinesia score was assessed between 0-12 points after 10 minutes of block application. Eye movements were measured over three points in each of the four quadrants as follows: 3, full eye movement and 0, no movement. The sum of the movement scores across all four quadrants was recorded as the akinesian score. An eye with full movement was scored as 12, and an immobile eye was scored as 0. If the akinesia score was four or less, the block was considered successful.
Time frame: The akinesia score was assessed at the beginning of surgery till the first 15 min.
The mean arterial pressure (MAP) measurement
The mean arterial pressure (MAP) was recorded in the preoperative period, at minutes 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 intra-operatively, and at 10, 20, 30, and 40 minutes postoperatively in the recovery room.
Time frame: The mean arterial pressure was recorded from baseline up to 40 minutes after surgery
The heart rate (HR) measurement
The heart rate (HR) was recorded in the preoperative period, at minutes 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 intra-operatively, and at 10, 20, 30, and 40 minutes postoperatively in the recovery room.
Time frame: The heart rate (HR) was recorded from baseline up to 40 minutes after surgery
The oxygen saturation (SpO2) measurement
The oxygen saturation (SpO2) was recorded in the preoperative period, at minutes 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 intra-operatively, and at 10, 20, 30, and 40 minutes postoperatively in the recovery room.
Time frame: The oxygen saturation (SpO2) was recorded from baseline up to 40 minutes after surgery
Surgeon satisfaction
They were asked to score over 10 point scale. Surgeon satisfaction was evaluated using 10 point scale ( 0 = not satisfied at all and 10 = very satisfied)
Time frame: Surgeon satisfaction was queried at the end of the surgery till the first 15 min.
Patient satisfaction
They were asked to score over 10 point scale. Patient satisfaction was evaluated using 10 point scale ( 0 = not satisfied at all and 10 = very satisfied)
Time frame: Patient satisfaction was questioned 24 hours after surgery
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