Optical Nerve Sheath Changes During Head Down Laparoscopy

Study Overview
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Brief Summary
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Patient undergoing laparoscopic radical prostatectomy in steep trendelenburg position are at risk to develop complication from brain edema. Ultrasound assessment of optical nerve sheath diameter is a simply, non-invasive method to estimate the increase of intracranial pressure. It is unknown how optical nerve sheath diameter changes after prolonged head down position.

Official Title
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Optical Nerve Sheath Diameter Changes During Steep Trendelenburg Position for Laparoscopic Prostatectomy

Conditions
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Intracranial Hypertension, Brain Edema, Pneumoperitoneum, Surgery, Laparoscopic

Intervention / Treatment
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* Diagnostic Test: Optical nerve sheath diameter ultrasound measurement


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients undergoing elective laparoscopic prostatectomy in steep Trendelenburg position American Society of Anesthesiologists risk I-III Exclusion Criteria: Age <18 or >70 years American Society of Anesthesiologists risk >III Assumption of beta-2-blockers, diuretics Heart failure with NYHA class ≥ IIb Diabetes with ocular (i.e. retinopathy), neurologic (i.e. peripheral neuropathy), or renal complications History of cardiac surgery, thoracic surgery, suprainguinal vascular surgery, head surgery, ocular surgery, stroke, hydrocephalus.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Steep Trendelenburg<br>Patients undergoing elective laparoscopic prostatectomy in steep Trendelenburg position (25 degrees head down position) | Diagnostic Test: Optical nerve sheath diameter ultrasound measurement<br>* In cases: ultrasound measurement of the diameter of the optical nerve sheath at (T1) baseline before the induction of general anesthesia (5 min after the beginning of mechanical ventilation in supine position); (T2) after 10 min from 25 degrees head down positioning and with pneumoperitoneum insufflation; (T3) after 60 min from T2, in head down position; (T4) after 10 min from tracheal tube removal, in supine position. In healthy controls: ultrasound measurement of the diameter of the optical nerve sheath at (T1) baseline in supine position; (T2) after 10 min from 25 degrees head down positioning; (T3) after 60 min from T2, in a head down position; (T4) after 10 min from positioning supine<br>|
| Healthy controls<br>Healthy awake volunteers undergoing steep Trendelenburg position (25 degrees head down position) | Diagnostic Test: Optical nerve sheath diameter ultrasound measurement<br>* In cases: ultrasound measurement of the diameter of the optical nerve sheath at (T1) baseline before the induction of general anesthesia (5 min after the beginning of mechanical ventilation in supine position); (T2) after 10 min from 25 degrees head down positioning and with pneumoperitoneum insufflation; (T3) after 60 min from T2, in head down position; (T4) after 10 min from tracheal tube removal, in supine position. In healthy controls: ultrasound measurement of the diameter of the optical nerve sheath at (T1) baseline in supine position; (T2) after 10 min from 25 degrees head down positioning; (T3) after 60 min from T2, in a head down position; (T4) after 10 min from positioning supine<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Optical nerve sheath diameter changes during steep Trendelenburg position | changes of optical nerve sheath diameter in millimeters measured by ultrasound in patients undergoing laparoscopic radical prostatectomy and in healthy volunteers | 2 months |