A comparative evaluation between median and paramedian approaches for sub-arachnoid block in elderly patients

Abstract

INTRODUCTIONSubarachnoid (spinal) block is a safe and effective form of anaesthesia when the surgical site is located on the lower extremities or perineum. It is simpler, cheaper and offers better physiological benefits with lesser complications than general anaesthesia. 1 It can be given by either median or paramedian approach. For the midline approach, the desired interspace is palpated and local anaesthetic is injected into the skin and subcutaneous tissue. The introducer is placed with a cephalad angle of 10 to 15 degree followed by passing of the spinal needle through the introducer. The needle goes through the subcutaneous tissue, supraspinous ligament, interspinous ligament, ligamentum flavum, epidural space, dura mater, and subarachnoid mater in order to reach the subarachnoid space. If the patient has a heavily calcified interspinous ligament (as seen in elderly patients) or difficulty in flexing the spine, a paramedian approach is used for spinal anaesthesia.After identifying the correct level for spinal anaesthesia placement, the spinous process is palpated. The needle is inserted 1 cm lateral to this point and directed toward the middle of the interspace. The ligamentum flavum is usually the first resistance felt. When the spinal needle goes though the dura mater, a pop is often appreciated. Accurate identification of the subarachnoid space is very important as multiple attempts at needle ABSTRACT Background: Spinal anaesthesia in elderly patients is frequently associated with significant technical difficulties. Spinal anaesthesia can be given by either paramedian or median approach. Paramedian approach has been used as an alternative in case of failure with median approach. The goal of this study is to determine which of these two approaches should be preferred as a first choice of spinal anaesthesia in elderly patients. Methods: The study included 100 patients of either sex, aged 50 years and above, who received spinal anaesthesia either with the midline approach (group M, n=50) or paramedian approach (group PM, n=50). Results: The success rate of paramedian group was 100% as compared to 96 % in median group. The first attempt success rate was 90% in group PM and 70% in group M. Paraesthesia was felt in 5 patients (10%) in midline group and in 2 patients (4%) in paramedian group. Hemorrhagic tap was seen in 2 patients each in both the groups . None of the patients in Group M had postdural puncture headache (PDPH) as opposed to 2 patients in Group M. Conclusions: Thus the study conclude that paramedian approach is a better approach for spinal anaesthesia in elderly patients in terms of success rate, success at first attempt, complications like paraesthesia, PDPH and failure of subarachnoid block. Thus study recommends the routine use of paramedian approach for sub-arachnoid block in elderly patients as first choice.

A Comparison between The Incidence of Paresthesia in Median and Paramedian Approaches of Intrathecal Anesthesia in Parturients Undergoing Cesarean Sections: A Randomized Controlled Trial

“…Our results were consistent with the results of Singh et al, who compared the two approaches in elderly patients above fifty, and found that 10% of the median approach group suffered from paraesthesia, compared to only 4% in the paramedian group [11].…”

A randomized comparative study on median and paramedian approaches for subarachnoid block using sprotte needle in the cesarean section: Quest for the best

“…The result proved that the difference between two groups was statistically significant ( P = 0.041). [ 9 ] Our study was similar to the study conducted by Ahsan-ul-Haq et al . concluded that In Group M, 5 (10%) patients required more than one attempt, while in Group PMM 2 (5%) patients required.…”

Evaluation Of The Median And Paramedian Approach In Spinal Anesthesia In Elderly Patients

“…In contrast, Rabinowitz et al 8 found that the success rate was 85% with the PA and 45% with the MA in their study in which 40 patients were included. In other similar studies, the success rate was found to be 100% with the PA and 90% with the MA 9,10 . In this study, the success rate was found to be 90.5% with the PA and 79.1% with MA, which is similar to studies 9,10,12 .…”

“…However, it was stated that longer spinal needles should be used for the PA. The success rate was found to be 90% with the PA and 70% with the MA by Sing et al 9 , 92% with the PA and 68% with the MA by Ali et al 7 , and 60% with the by Ahsan ul-haq et al 10 . In our study, the attempt from another space due to failure was not statistically significant, however, it was more with the MA.…”

“…In the MA, supraspinous, interspinous, and ligamentum flavum are passed. In elderly patients, the procedure is painful and difficult due to their reduced ability to complete the flexion position due to the decrease in the distance between the joints, calcification, and degeneration 7,9 . In the PA, since the ligamentum flavum directly reaches from the paravertebral muscles instead of supraspinous and interspinous ligaments, problems due to degenerative change in elderly patients could be avoided 10,11 .…”