A Randomized Comparative Study on Median and Paramedian Approaches for Subarachnoid Block using Sprotte Needle in the Cesarean Section: Quest for the Best.

Background: Since 1898 when August Bier, introduced spinal analgesia, there is lot of advancement made in the technique. There are various approaches and techniques for subarachnoid block. Aim: The aim of this study is to compare median and paramedian approach for spinal anesthesia for cesarean delivery using Sprotte needle in terms of number of attempts, success rate, adverse effects, and complications. Materials and
Methods: One hundred patients were randomly divided into two equal groups and underwent subarachnoid block in median and paramedical block for elective cesarean section.
Results: There is no significant difference between the two groups. Mean with standard deviation in the number of attempts for subarachnoid block through media and paramedian approach is 1.18 ± 0.48 and 1.06 ± 0.24, respectively (P = 0.51). The incidence of postdural puncture headache (PDPH) and lower backache was insignificant in both the groups (P = 0.218 and 0.646, respectively). Conclusions: Paramedian approach should not be considered as a reserve technique for spinal anesthesia and can be used as popularly as the median approach. Copyright:

INTRODUCTION

The pain is a perfect misery; the worst of all evils and 29 excessive over turns all patience. The medical profession has attempted the various methods of pain relief from the ancient time. August Bier in 1898 introduced spinal analgesia which achieved wide spread popularity worldwide. In this method, subarachnoid space was utilized to deposit the local anesthetic solution like cocaine.[1] In spite of marked improvement in the field of general anesthesia, spinal block still holds its space in various surgical procedures. Spinal anesthesia also provides additional benefits of decreased surgical stress response, increased myocardial activity, rapid recovery of bowel function, and reduce risk of thromboembolism.[2] Spinal anesthesia can be achieved either through the median or paramedian approach. Headache or postdural puncture headache (PDPH) is one of the widespread complications following spinal anesthesia. The midline approach is most commonly practiced for the administration of spinal anesthesia. The paramedian approach is useful especially in difficult cases, in obese patients, in pregnant patients and in geriatric patients. We conducted a prospective study of patients who underwent cesarean delivery using spinal anesthesia by both midline and paramedian approach by using Sprotte needle to evaluate the safety and efficacy of paramedian approach.

MATERIALS AND METHODS

Aim

The aim of this study is to compare the median and paramedian approach for spinal anesthesia for cesarean delivery using Sprotte needle in terms of number of attempts, success rate, adverse effects, and complications.

After taking approval from the Institutional Ethical Committee (no 94. IEC, RIMS dated February 16, 2019), the study was registered in Clinical Trial Registry-India (ICMR-NIMS) (No: CTRI/2021/02/031083). The study is a randomized controlled trial done as per the consort guidelines.

An informed written consent from the patients was taken in this prospective randomized study. The study was conducted on 100 consecutive patents of American Society of Anesthesiologists (ASA) physical status class II, who underwent cesarean delivery under spinal anesthesia. Patients were included who gave consent, of age 20–40 years and belongs to ASA PS class II. Patients who were excluded are with preexisting neurological or spinal disease, cardiovascular or respiratory impairment, local or systemic infection, with history of spinal surgery or with history of recurrent headache or who had experienced PDPH on a previous occasion. All patients underwent preanesthetic evaluation. One hundred pregnant patients were randomly assigned who underwent cesarean delivery under spinal anesthesia into two groups of 50 patients each. Randomization in group allotment was done by the lottery method. Group M (n = 50) who received spinal anesthesia in L3-L4 subarachnoid space using Sprotte needle with the median approach. Group PMM (n = 50) who received spinal anesthesia in L3-L4 subarachnoid space using Sprotte needle with paramedian approach. Following observations were made on each patient and were recorded in predesigned case record per forma. Parameters recorded were the number of attempts, time of onset for sensory block, time of onset of motor block, duration of sensory block, adverse effects, and complication and incidence of headache and lower backache. The Visual Analog Scale was used to assess the severity of the pain. Neonatal assessment will be performed by assessing the APGAR score of neonatal at 1 and 5 min. Side effects and complications including PDPH, lower backache, hypotension, bradycardia, nausea vomiting, pruritis, shivering, neurological complication, and others were also recorded. Statistical analysis was performed using the SPSS version 20 software (SPSS Inc. IBM 2009; Chicago, United States). The continuous variables were expressed as means ± standard deviation and categorical variables were expressed as proportions. The analysis of variance test was used for the comparison of patient characteristics and differences of variables among the two groups. For nonparametric variables, Wilcoxon − Mann-Whitney test was performed. P < 0.05 was considered statistically significant.

RESULTS

The number of attempts shown in Table 1 depicts a nonsignificant result with a P = 0.51. In fact successful subarachnoid access was more in PMM group as compared to Group M. The duration of analgesia was almost same in both the groups and achieved a nonsignificant result (P = 0.331), as shown in Table 2. The APGAR score shown in Table 3 was similar in both the groups. Table 4 showing complications shows that hemorrhagic tap was noted in 6 (12%) of patients in Group M and in 9 (18%) of patients in Group PMM. The result yielded a nonsignificant result with P = 0.401. PDPH was noted in 8 (16%) of patients in Group M and in 4 (8%) of patients in Group PMM, as shown in Table 5. Medication required (number of patients) to treat PDPH in 7 (16%) of patients in Group M and in 3 (6%) of patients in Group PMM which was again with a P = 0.182. The presence of paresthesia was observed in 8 (16%) of patients in Group M and in 4 (8%) of patients in Group PMM. Lower backache was observed in three (6%) of patients in Group M and in 2 (4%) of patients in Group PMM. Table 4 also shows hypotension which was noted in 37 (74%) of patients in Group M and in 37 (74%) of patients in Group PMM. Bradycardia was noted in 3 (6%) of patients in Group M, and no bradycardia was noted in Group PMM. Nausea and vomiting were observed in four and two patients in Group M and Group PMM, respectively. As all patients were catheterized urinary retention could not be monitored. Other complications such as shivering, pruritis, respiratory depression, and neurological complications were not observed in any patients of both the groups. There was no clinical and statistical significance in the incidence of side effects in both the groups, as shown in Tables 4 and 5.

Table 1

Number of attempts

	Group M, n (%)	Group PMM, n (%)
One	43 (86)	47 (94)
Two	5 (10)	3 (6)
Three	2 (4)	0 (0)
Total	50	50
Mean±SD	1.18±0.48	1.06±0.24
P	0.51

SD=Standard deviation

Table 2

Duration of analgesia

Time (s)	Group M (n=50)	Group PMM (n=50)
121-180	46	49
181-240	4	1
241-300	0	0
Total	50	50
Mean±SD	157.9±15.26	157.4±12.42
P	0.331

SD=Standard deviation

Table 3

APGAR score

APGAR Score	Group M		Group PMM
	1 min	5 min	1 min	5 min
<5	0	0	0	0
5-7	3	0	2	0
8-10	47	50	48	50
Mean±SD	8.76±0.87	8.98±0.77	8.66±0.8	8.86±0.78

SD=Standard deviation

Table 4

Sideeffects and complications

Events	Group M (n=50), n (%)	Group PMM (n=50), n (%)	P
Hemorrhagic tap	6 (12)	9 (18)	0.401
PDPH	8 (16)	4 (8)	0.218
Medication required (number. of patients) to treat PDPH	7 (14)	3 (6)	0.182
Presence of parasthesia	8 (16)	4 (8)	0.218
Lower backache	3 (6)	2 (4)	0.646
Hypotension	37 (74)	37 (74)	1
Bradycardia	3 (6)	0	0.079
Nausea/vomiting	4 (8)	2 (4)	0.4
Pruritus	None	None	None
Shivering	None	None	None
Neurological complications	None	None	None
Others	None	None	None

PDPH=Postdural puncture headache

Table 5

Incidence of postdural puncture headache

Events	Group M (n=50), n (%)	Group PMM (n=50), n (%)	P
PDPH	8 (16)	4 (8)	0.218
Lower back ache	3 (6)	2 (4)	0.646

PDPH=Postdural puncture headache

PDPH was noted in 8 (16%) of patients in Group M and in 4 (8%) of patients in Group PMM. Lower backache was observed in 3 (6%) of patients in Group M and in 2 (4%) of patients in Group PMM.

DISCUSSION

In this study, Group M (n = 50) who received spinal anesthesia using Sprotte needle with median approach and Group PM (n = 50) who received spinal anesthesia using Sprotte needle with para median approach were used to compare success rate, attempt, complications, APGAR score, and quality of analgesia.

Headache or PDPH is the most common complication following spinal anesthesia or analgesia and presents hours to days after the dural puncture.[2] The loss of cerebrospinal fluid (CSF) from the intrathecal space is the main causative factor. The CSF leakage results in fall in intracranial CSF volume and CSF pressure.[3] It causes gravitational traction on the pain sensitive structures causing headache.[45] The loss of CSF may result in compensatory intracranial vasodilatation. Relative CSF hypovolemia results in painful possibly adenosine receptors-mediated cerebral vasodilatation.[6] It is characterized by dull or throbbing headache and the severity is increased in an upright posture and lesser in supine position. The incidence of headache following CD was ranging from 0% to 4%. The technique, type of needle, and number of puncture may influence the incidence of complications such as PDPH. The incidence varies with size of needle. Greater the size of the needle, higher the incidence of PDPH. The other causes for PDPH should be evaluated or excluded before confirming the diagnosis of PDPH: migraine, tension or cluster headache, neuralgia, subdural hematoma, lactation headache, postpartum cerebral angiopathy, preeclampsia and caffeine withdrawal.[7] Demographic data of patient included in the study were comparable with respect to height, weight, and mean age of the each group. Mean age of patients included in the study was 62% of patients in Group M and 76% of patients in Group PMM belonged to the age group between 21 and 30 years and mean age in Group M was 23.56 ± 4.32 years and mean age in Group PMM was 24.28 ± 4.11 years and were comparable among two groups (P > 0.05). Preoperative vitals and investigations were within the normal range. In our study, we observed that the mean of number of attempts 1.18 ± 0.48 in Group M and 1.06 ± 0.24 in Group PMM, which was statistically not significant. More than one attempt was required in 7 patients (13%) in the midline group and 4 patients (6%) in the paramedian group. First attempt success rate was 86% in midline group and 94% in the paramedian group. In the similar study conducted also concluded that the success rate after the first attempt was 85% for Group PMM and 45% for Group M (P < 0.02).[8] In a similar study conducted by Pooja et al., observed that the first attempt success in median approach was 48% while first attempt success in paramedian approach was 70%. 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.[10] Our study had similar results which showed that the paramedian approach has an advantage of less no of attempts than midline approach. We observed that hemorrhagic tap was noted in 6 (12%) of patients in Group M and in 9 (18%) of patients in Group PMM. In a similar study conducted by Pooja et al. observed that in the median group, bloody tap was found in 6% patients while in paramedian group, it was found in 12% patients.[9] The difference was not statistically significant (P = 0.295). There are more chances of traumatic complications in paramedian approach, because epidural veins tend to be situated laterally.[11] The target area is large in the paramedian approach. Because the needle is introduced laterally, any limitation of the spinous process is avoided. It does not require the parturient to reduce the lumbar lordosis fully. The paramedian approach may result in decreased incidence of PDPH. Studies show that there is less CSF leak in the paramedian approach than the median approach.[12] It may be because of a valvular mechanism produced which prevents the excess amount of leakage of CSF. The valvular mechanism is created because the dura mater and arachnoid are perforated at different angles. In our study, we observed that the incidence of lower backache was 3 (6%) of patients in Group M and 2 (4%) of patients in Group PMM. However, Sohail et al. concluded that paramedian approach is better than median approach, with significant results.[13]

CONCLUSIONS

In our study, results were comparable and statistically not significant between median and paramedical approach. Based on the results of our study and above discussion, we conclude that paramedian approach is equally effective and may be helpful in reducing the incidence of PDPH, with higher success rate, lesser number of attempts, and paraesthesia, and it can be easily performed in pregnant patients. There are studies claim that paramedian approach is superior to median approach, but in our study, both approach appeared to have similar efficacy in terms of success rates, APGAR score, complications, and PDPH. Both the techniques have their own advantages, but the difference was not significant in our study.

We can conclude that both median and paramedian approach are equally effective and it depends on the anesthesiologist choice which procedure should he or she choose.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.