Reattachment of the retina requires intraocular gas. What are the
different types of gases that can be used, and what are the anesthetic
implications of their use?
The surgeon may use intraocular air,
sulfurhexafluo-ride (SF6), octafluorocyclobutane (C4F8),
or perfluoro-propane (C3F8). Since these gases are mixed
with air in concentrations that normally do not expand, they will expand in
volume with the coincident use of nitrous oxide (N2O). If the
procedure is performed under gen-eral anesthesia, N2O should be
discontinued at least 10–15 minutes prior to intraocular gas injection. In the
case of C3F8 and SF6, N2O is
contraindicated for at least 30 days to prevent subsequent increases in intraocular
pressure. Intraocular gases are resorbed very slowly. Occasionally, intraocular
silicone is injected, which does not resorb.
Postoperatively, intraocular gas may be
directed to a par-ticular portion of the retina by adjusting the patient’s
position. Prone, lateral decubitus, and sitting are commonly prescribed
positions. Such departures from standard postanesthetic nursing care mandate an
awake, cooperative patient.
Regional anesthesia techniques are most
compatible with these postoperative requirements.
Nausea and vomiting are not only frequent
sequelae of anesthesia but may also indicate increased intraocular pressure
secondary to overinflation with intraocular gas. Nausea and vomiting often
follow scleral buckling without gas injection and may be reduced by
administration of perioperative ketorolac to diminish traction and