Intra-ocular Pressure and Ventilation

Study Overview
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Brief Summary
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Background: Positive pressure pneumoperitoneum (PP) may involve adverse pathophysiological changes, including increased intra-thoracic and ocular pressure, when combined with standard ventilation. High frequency jet ventilation (HFJV) was reported to reduce the adverse cardiovascular effects during laparoscopic cholecystectomy. Aim: To study the effects of HFJV on intra-ocular pressure changes (reflecting intra-cranial pressure) during laparoscopic surgery under PP.

Detailed Description
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Patients and methods: The investigators studied 2 groups of patients electively scheduled for laparoscopic cholecystectomy. The study group included 10 patients that were ventilated by high frequency jet ventilation (HFJV). In the control group (16 patients) the investigators used the standard intermittent positive pressure ventilation (IPPV). Both groups were matched according to clinical and hemodynamic parameters. Intra-ocular pressure was measured by a senior ophthalmologist that was blinded to the ventilation technique. Laparoscopic surgery was done as usual, and the intra-peritoneal pressure was automatically set on 14 mmHg. Statistical significance was considered whenever P value was less than 0.05. The investigators anticipate that the use of HFJV during laparoscopic operations under PP may prevent increased intra-ocular pressure that accompanies increased intra-abdominal pressure under conventional ventilation (IPPV).

Official Title
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The Effects of High Frequency Jet Ventilation on Intra-ocular Pressure During Laparoscopic Operations (Lap. Cholecystectomy) With Positive Pressure Pneumoperitoneum

Conditions
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Pneumoperitoneum

Intervention / Treatment
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* Procedure: HFJV ventilation
* Procedure: IPPV ventilation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing elective laparoscopic cholecystectomy Exclusion Criteria: Ophthalmologic and severe Cardiopulmonary diseases

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

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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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: IPPV ventilation<br>standard intermittent positive pressure ventilation in patients undergoing laparoscopic cholecystectomy | Procedure: IPPV ventilation<br>* The investigators used the Perkins tonometer for monitoring intra-ocular pressure. Evaluation of intra-ocular pressure was done before induction of anesthesia, end of induction, during surgery and at the end of surgery.<br>|
| Other: HFJV ventilation<br>high frequency jet ventilation in patients undergoing laparoscopic cholecystectomy | Procedure: HFJV ventilation<br>* The investigators used the Perkins tonometer for monitoring intra-ocular pressure. Evaluation of intra-ocular pressure was done before induction of anesthesia, end of induction, during surgery and at the end of surgery.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intra-ocular pressure |  | During procedure |