{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T19:30:07Z","timestamp":1786649407342,"version":"build-2736575974"},"reference-count":18,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"4","license":[{"start":{"date-parts":[[2025,9,3]],"date-time":"2025-09-03T00:00:00Z","timestamp":1756857600000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0"}],"content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2025,10]]},"abstract":"<jats:sec>\n                    <jats:title>Background:<\/jats:title>\n                    <jats:p>Pneumatic tourniquets are used in orthopedic surgeries to provide a bloodless surgical area and reduce blood loss. Tourniquet inflation causes metabolic changes, leading to cerebral vasodilatation and increased intracranial pressure (ICP). A new noninvasive method to measure optic nerve sheath diameter (ONSD) via ultrasonography to detect the raised ICP is reliable, inexpensive, and can be repeated many times.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Materials and Methods:<\/jats:title>\n                    <jats:p>In this prospective observational study, 23 patients aged between 16 and 60 years, undergoing elective lower limb orthopedic surgeries under spinal anesthesia were included. After pre-anesthetic evaluation and obtaining informed written consent, an ocular ultrasound was performed to measure baseline ONSD in both eyes. Spinal anesthesia was administered and A pneumatic thigh tourniquet was applied as close as possible to the limb root and inflated to 150 mmHg\u2013250 mmHg above the systolic blood pressure. A total of 5 measurements of ONSD were taken by the investigator (anesthetist): before giving spinal anesthesia, after giving spinal anesthesia, before tourniquet deflation, within 5 min, and after 10 min of tourniquet deflation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>\n                      In our study, the mean age of subjects was 34.57 \u00b1 13.5 years. The majority were males (83%). The subjects showed an increase in ONSD after pneumatic tourniquet deflation in comparison with the baseline values, in the left eye [0.543 cm \u00b1 0.021,\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      &lt; 0.001] and the right eye [0.549 cm \u00b1 0.021,\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      &lt; 0.001], which were statistically significant.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion:<\/jats:title>\n                    <jats:p>\n                      The impact of pneumatic tourniquet deflation on ONSD measurements recorded by ultrasound in lower limb orthopedic surgeries was significant and this change occurred with a simultaneous increase in end-tidal carbon dioxide (EtCO\n                      <jats:sub>2<\/jats:sub>\n                      ).\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.4103\/sja.sja_150_25","type":"journal-article","created":{"date-parts":[[2025,9,3]],"date-time":"2025-09-03T12:01:10Z","timestamp":1756900870000},"page":"521-525","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":0,"title":["The effects of tourniquet deflation on optic nerve sheath diameter in lower limb orthopaedic surgeries"],"prefix":"10.4103","volume":"19","author":[{"given":"Saraswathi","family":"Nagappa","sequence":"first","affiliation":[{"name":"Department of Anesthesiology, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Riya","family":"Ravindran","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yathish Sarthavalli","family":"Krishnamurthy","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chandrakala","family":"Chandrashekar","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2025,9,3]]},"reference":[{"key":"R1-20260421","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1213\/00000539-199801000-00018","article-title":"Changes in oxygen consumption and carbon dioxide elimination after tourniquet release in patients breathing spontaneously under epidural anesthesia","volume":"86","author":"Takahashi","year":"1998","journal-title":"Anesth 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