الفهرس 
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Abstract
The aim of sedation is to minimise anxiety without increasing risk while providing the maximum degree of safety. The effects of the sedation should be easily controlled, with smooth onset, rapid recovery and minimal side-effects. Ideally, the patient undergoing ophthalmic surgical procedures should be fully conscious, responsive, and without anxiety, discomfort or pain.
Ketofol is an intravenous anesthetic agent that could be used for:
1- Anesthetic induction
2- Procedural Sedation and analgesia
The combination of ketamine with propofol reduces the levels of both anesthetic and hypnotic doses of propofol, resulting in fewer adverse event and shorter recovery time.
Ketofol is a very useful combination in ophthalmic procedures performed under local anesthesia but our patients need to be monitored and the ratios of the mixtures must be selected carefully. Using this drug combination is theoretically compelling, as the sedative effects of propofol are thought to counter balance the nauseant and psychomimetic effects of ketamine. The ability to provide deep sedation with lower doses of ketamine may achieve shorter recovery times compared to use of ketamine alone. Moreover, ketamine provides an analgesic effect during propofol PSA that may result in fewer adverse airway events, reduces respiratory depression, and provides more hemodynamic stability.
A decision has to be made whether the ratios for induction, bolus administration and continuous infusion should be the same. from all previous studies we can say that
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there are potential advantages when ketofol is used and where moderate sedation and analgesia is targeted; Lower doses of propofol can be used thus limiting propofol-induced respiratory depression. seen with opiate administration. phenomena depending on the ratios of ketamine and propofol used in the mixture.
*A ratio of 3:1 (ketamine/Propofol) is the optimum combination for bolus dosing, achieving a rapid onset of sedation-analgesia, the shortest emergence time, and antiemetic effect. Ratios higher than this (1:1–2:1) have increasingly prolonged recovery time. In addition, because of higher ketamine doses, the likelihood of emergence reaction and emesis may increase. In lower ratios, recovery time is faster with improved sedation quality and less adverse events. The ratio for the infusion regimen, however, seems best at 4:1 because the overall dose of both drugs required to achieve the same clinical end points is less with a constant infusion, so the ketamine component, which is responsible for the much longer recovery time, can be reduced and a consistent depth of sedation is achieved .
*This current study suggests that Ketofol (ketamine/Propofol) concentration at ratios 3:1 and 4:1 may provide effective and safe sedation for patients undergoing ophthalmic procedures under regional anesthesia. An intravenous infusion of a 4:1 ratio is a suitable alternative for delivering Ketofol; this provides more stability and consistency of sedation depth and less need for top-up doses that may lead to overshoot of sedation and a delayed recovery.
*Recommendation: Further randomizes control trials on the use of Ketofol infusion with ratio 4:1 as a sedation regimen for prolonged ophthalmic operations performed under regional anaesthesia, are required to validate this result.