الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 133 |  |  |
| | | from | 133 | | |
Abstract
SUMMARYUMMARY UMMARY
trabismus is one of the common health problems among the children.
In 1908, Aschner described a decrease in heart rate as a consequence of applying pressure directly to the eyeball. This phenomenon would eventually be termed ―the oculocardiac reflex‖ and is defined clinically as a decrease in heart rate by 10% following pressure to the globe or traction of the ocular muscles. The reported incidence of the oculocardiac reflex varies from 14% to 90%, depending on the study, making it relatively common
The incidence of the oculocardiac reflex decreases with age and tends to be more pronounced in young, healthy patients, which is clinically significant for pediatric as it is observed with greatest incidence in young healthy neonates and infants undergoing strabismus surgery.
Peribulbar block: a 26 gauge needle (25mm) / 27 gauge 1/2 inch (12mm) is inserted as far laterally as possible in the inferotemporal quadrant. Once the needle is under the globe, it is directed along the orbital floor, passing the globe equator to a depth controlled by observing the needle/hub junction reaching the plane of the iris. After negative aspiration for blood, with the globe in primary gaze, 4 to 5 cc of local anaesthetic agent is injected.
S
Summary
85
By this procedure, all extraocular muscles including superior oblique can be paralyzed. The local anaesthetic solution diffuses through the orbital septum and orbicularis muscle can also be paralyzed. A separate eyelid block might not be required with this technique
Single injection, peribulbar block using a short needle and a small volume is a safe and effective technique when combined with general anesthesia in pediatric ophthalmic surgery.
Levobupivacaine is a long acting, amide-type local anaesthetic A trend towards a longer sensory block with levobupivacaine was seen in some studies, and may be related to the greater vasoconstrictive activity of levobupivacaine
Lidocaine is Intermediate-acting local anesthetic (amide type), the efficacy profile of lidocaine as a local anesthetic is characterized by a rapid onset of action and intermediate duration of efficacy. Therefore, lidocaine is suitable for infiltration, block, and surface anesthesia.
Hyaluronidase is an enzyme which degrades hyaluronan (HA) and has diverse clinical applications resulting from its ability to facilitate the dispersion and/or absorption of an array of medications and fluids. It provides rapid penetrance of anesthetic agents, particularly to locations difficult to access. In ophthalmology, hyaluronidase is used most often as an adjunct to local anesthesia for retrobulbar, peribulbar, or sub-Tenon‘s
Summary
86
blocks. The main goal of this Thesis is to evaluate and assess the efficacy of Levobupivacaine 0.5% and Lidocaine 2% if injected in peribulbar block in preventing the incidence of Oculocardiac reflex in Pediatrics patients undergoing strabismus surgery.
Three groups were allocated group C received general anaesthesia combined with pre-emptive atropine, group L received general anaesthesia combined with Peribulbar block with Lidocaine 2 % and group LB which received general anaesthesia combined with peribulbar block with Levobupivacaine 0.5%.
The secondary goal is to evaluate the effect of peribulbar block if combined with general anesthesia on post-operative pain and analgesia.
It was found that the use of peribulbar block with lidocaine 2% decreased the incidence of OCR in paediatrics undergoing strabismus surgery under GA by 81 % with p value = 0.002 which is significant for attenuation of the reflex and post operative pain.
Also it was found that the use of peribulbar block with levobupivacaine 0.5% in paediatrics undergoing strabismus surgery under GA decreased the incidence of OCR by 61.9% with p value = 0.002 which is significant for reduction of the incidence of OCR and highly significant for the post operative pain by 95.25 % with p value = 0.001.
Summary
87
While the use of pre-emptive IV Atropine didn‘t significantly reduce the OCR in the paediatrics group as it decreased the incidence of OCR only by 28.6% and has no rule in controlling the post operative pain.
In this study we found that group L which received peribulbar lidocaine 2 % was the most successful group regarding blocking the occurrence of the OCR and with acceptable post-operative pain control results.
While group LB which received peribulbar levobupivacaine 0.5% inferior to group L regarding blocking the OCR but with a very high significant results regarding controlling the post-operative pain which makes it superior to group L according to post-op pain results.
The group C which received the pre-emptive IV Atropine was the least successful group regarding blocking the OCR and for the post-op pain which makes it inferior to the two previous groups L and LB regarding the OCR and the post-operative pain while it has the lowest incidence of complications by 23.8% which makes it superior to the two other groups regarding the complications.
The use of peribulbar block with lidocaine 2 % in combinations with General anaesthesia is very effective against the incidence of OCR in children undergoing strabismus surgery and superior to the Iv pre-emptive Atropine with higher surgeon satisfaction while the use of peribulbar levobupivacaine 0.5%
Summary
88
combined with general anaesthesia has a great role in post-operative pain control with superior patient satisfaction, on the other hand the atropine is a very important emergency drug but this study found that it has a very minor role in both preventing the OCR and post-operative pain control in addition to subjecting the patients to the tachycardia and other complications like blushing so it‘s not recommended by this study