Prone Position, Blood Volume, Intraocular Pressure
Conditions
Keywords
pulse pressure variation, intraocular pressure, optic sheath diameter, spine surgery, prone position
Brief summary
The purpose of this trial is to compare the effect of different fluid volume infusion on ocular parameters in patients undergoing spine surgery in prone position.
Detailed description
In the prone position, the intraocular pressure and optic nerve sheath diameter increase progressively with time as compared with those in the supine position. Excessive fluid infusion may further increase intraocular pressure and optic nerve sheath diameter. Pulse pressure variation (PPV) is a dynamic index which can effectively assess fluid responsiveness during general anesthesia.Therefore,the investigators have designed a study to compare the effect of different fluid volume infusion guided by low and high PPV indices on intraocular pressure and optic nerve sheath of patients undergoing prone spine surgery with general anesthesia. One group of the patients will receive relatively loose fluid infusion (target value of PPV: 6%-9%),while the other group of the patients will receive limited fluid infusion (target value of PPV: 13%-16%).
Interventions
Patients in both groups will receive Ringer's lactate solution continuously during operation with different infusion volume.
PROCEDURESpine surgery under general Anesthesia in the prone position
The surgery, general anesthesia, and the placement of the prone position will be performed according to the standard procedures.
Sponsors
Huashan Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Intervention model description
Patients will be randomly assigned to the limited fluid infusion group and the loose fluid infusion group.
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
* Scheduled for elective spine surgery in prone position under general anesthesia * American Society of Anesthesiologists (ASA) physical status I or II * Have signed consent form
Exclusion criteria
* History of eye disease or eye surgery * Pregnancy or breast feeding * Known Allergy to latex or Ringer's lactate solution * Hyperlactacidemia，uncontrolled hypertension, diabetes mellitus, arrhythmia, cardiovascular disease，chronic pulmonary disease, swelling of any body part, abnormal of liver or renal function, anemia, etc. * Body mass index（BMI）\>30 * Expected operation time \>6 hours * Estimated Intraoperative hemorrhage \>1000ml * Taking part in other clinical trials in the last 3 months or at present
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The change of intraocular pressure | 10min after anesthesia induction（supine1）, 10min after prone position(prone1), 1 hour after the prone position(prone2), 2 hour after the prone position(prone3),at the end of the surgery(prone4), and 10min after return to the supine position(supine2). | Intraocular pressure will be measured with a TONO-PEN AVIA handheld tonometer. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The change of the optic sheath diameter | 10min after anesthesia induction（supine1）, 10min after prone position(prone1), 1 hour after the prone position(prone2), 2 hour after the prone position(prone3),at the end of the surgery(prone4), and 10min after return to the supine position(supine2). | The optic sheath diameter will be measured with a Sonocite Portable Ultrasonic System EDGE. |
Countries
China
Outcome results
None listed