Background: Peribulbar block is the most common type of local anaesthesia administered for cataract surgery, and continuous efforts are on to minimize the patient discomfort along with achieving good akinesia.
Aims & Objectives: A double-blind, prospective and randomized study was carried out in our institute to compare the anaesthetic effects of Lignocaine+Bupivacaine+Hyaluronidase injected for peribulbar block vs medical conal block for phacoemulfication cataract surgery.
Materials and Methods: A total of 100 patients of both sexes aged 50-80 years of American Society of Anaesthesiologists grade 1 and 2, scheduled for phacoemulfication cataract surgery under monitored anaesthesiacare, were enrolled for the study. Patients were assigned into two groups of 50 each, Peribulbar block group (P) and medial conal block group (M). Group P received 10 ml of LA solution containing 5ml of 2% lignocaine, 5ml of 0.75% bupivacaine and 100 units of hyaluronidase through peribulbar route while group M received the same LA solution 2.5ml through medial conal route. Heart rate(HR), mean arterial pressure (MAP), pulse oximetry (SpO2), respiratory rate (RR), intraocular pressure (IOP), eye muscle movements score and quality of block were observed and recorded throughout the study period at regular interval. At the end of research project, the data was complied systematically and was subjected to statistical analysis using the ANOVA test with post hoc significance for continuous variables and chi-square test for qualitative data. Value of P<0.05 was considered significant and P<0.0001 as highly significant.
Results: Demographic characteristic, SpO2 and RR were comparable in both the groups. Mean HR and MAP were also comparable after a significant variation in the first 2-3 minutes (p<0.05). Onset and establishment of sensory and motor blocks were significantly earlier in P group (p<0.05). IOP decreased significantly during the first 6-7 min in the P group after administration of block. Duration of analgesia was prolongs in the P groupas compared to M group. The side effect profile revealed a higher incidence of nausea, vomiting, headache, dry mouth and dizziness in group P.
Conclusions: Administration of medial conal block not only decreases the total volume of LA to be used but also increases patient comfort level and sensory analgesia achieved is comparable to peribulbarblock. It also provides smooth operating conditions with a good sedation level as well by providing a wider safety margin of LA as side effects of LA are drastically reduced.