European Journal of Cardiovascular Medicine

Cesarean delivery is one of the most frequently performed surgical procedures worldwide, and regional anesthesia is the preferred technique due to its safety profile and efficacy [1]. Among various regional techniques, spinal anesthesia has emerged as the most commonly employed anesthetic method for elective and emergency cesarean sections, offering rapid onset, predictable effects, and minimal neonatal drug exposure [2]. However, the position of the parturient during the administration of spinal anesthesia is a critical determinant of the block characteristics, particularly onset time, level achieved, hemodynamic changes, and maternal comfort [3].

The two most commonly adopted positions for administering spinal anesthesia in parturients are the sitting position and the lateral decubitus position. The sitting position is often preferred due to ease of landmark identification and needle placement, especially in obese patients [4]. However, this position may be associated with increased risk of hypotension, delayed block onset, and patient discomfort [5]. Conversely, the lateral position offers greater comfort for the parturient and may reduce the incidence of vasodilation-related hypotension by minimizing sympathetic blockade [6]. It may also facilitate a more even distribution of anesthetic drug in the cerebrospinal fluid, leading to improved sensory and motor blockade profiles [7].

Levobupivacaine, the S(-) enantiomer of bupivacaine, has gained popularity in obstetric anesthesia due to its favorable pharmacological profile including lower cardiotoxicity and better sensory-motor differentiation [8]. Though extensively used in various regional techniques, evidence comparing the efficacy of levobupivacaine in different positions during spinal anesthesia in cesarean section remains limited.

In the context of maternal safety and neonatal outcomes, it becomes imperative to optimize every aspect of spinal anesthesia administration. Positioning during induction, though seemingly a procedural step, can significantly influence hemodynamic outcomes and anesthetic spread, particularly when plain levobupivacaine is used [9, 10].

This prospective study aims to compare the lateral versus sitting position during the administration of spinal anesthesia using plain levobupivacaine in parturients undergoing cesarean delivery, focusing on block characteristics, maternal hemodynamic parameters, and neonatal outcomes. Our goal is to identify the position that provides the optimal balance between efficacy and safety, ultimately enhancing both maternal and fetal outcomes in cesarean deliveries.

Study Design and Setting

This was a prospective observational study conducted in the Department of Anesthesiology at Government Medical College Anantnag.  Written informed consent was obtained from all participants.

Study Population

A total of 100 pregnant women scheduled for elective lower segment cesarean section (LSCS) under spinal anesthesia were enrolled. Participants were between 18 and 35 years of age, classified as American Society of Anesthesiologists (ASA) physical status  II, and carrying singleton, full-term pregnancies (gestational age 37–40 weeks).

Inclusion Criteria

* Singleton term pregnancy

* Elective cesarean section

* ASA grade  II

* BMI between 18 and 30 kg/m²

* Written informed consent

Exclusion Criteria

* Emergency cesarean section

* Known allergy to amide local anesthetics

* Coagulation disorders or on anticoagulants

* Infection at the puncture site

* Spinal deformities

* Pre-existing hypertension or cardiovascular disease

* Neurological or psychiatric disorders

Group Allocation

Participants were randomized into two groups (n = 50 each) using a computer-generated random number table:

Group S (Sitting Position): Patients received spinal anesthesia in a sitting position.

Group L (Lateral Position): Patients received spinal anesthesia in the left lateral decubitus position.

The anesthesiologist performing the block was aware of the allocation, while the observer recording intraoperative parameters and outcomes was blinded to group assignment.

Anesthetic Technique

On arrival to the operation theatre, all patients were preloaded with 10 mL/kg of Ringer lactate solution over 15–20 minutes. Standard ASA monitors (pulse oximetry, ECG, non-invasive blood pressure) were attached.

Under strict aseptic precautions and after skin infiltration with 2% lignocaine, spinal anesthesia was performed using a 25G Quincke needle at the L3–L4 interspace. A dose of 2.5 mL (12.5 mg) of 0.5% plain levobupivacaine was administered intrathecally. Patients were immediately positioned supine with a left uterine tilt using a wedge.

Parameters Recorded

The following parameters were recorded and analyzed:

1. Time to Onset of Sensory Block: Time from drug injection to achievement of T6 sensory level to pinprick.
2. Maximum Sensory Block Level: Recorded 10 minutes post-injection.
3. Time to Maximum Motor Block: Time taken to achieve Bromage score 3.
4. Duration of Motor Block: Time from block onset to return to Bromage score 0.
5. Hemodynamic Parameters: Heart rate, systolic and diastolic BP recorded at 2-minute intervals for the first 15 minutes, then every 5 minutes.
6. Incidence of Hypotension: Defined as a drop in systolic BP >20% from baseline or <90 mmHg, treated with IV mephentermine (6 mg).
7. Neonatal Apgar Scores: At 1 and 5 minutes.

Statistical Analysis

Data were analyzed using SPSS version 26.0. Continuous variables were expressed as mean ± standard deviation (SD), and categorical data as frequency and percentage. Student’s t-test was used for comparing continuous variables, and chi-square test for categorical data. A p-value <0.05 was considered statistically significant.

A total of 100 pregnant women undergoing elective cesarean section were enrolled in the study and equally distributed into two groups: Group S (sitting position) and Group L (lateral position), with 50 participants in each.

There was no statistically significant difference in age, height, weight, BMI, or gestational age between the two groups, indicating that the groups were demographically comparable [Table 1].

Table 1: Demographic Data of the Study Participants

The onset of sensory block was significantly faster in the lateral group compared to the sitting group. The maximum level of sensory block achieved was higher in the lateral group. The time to achieve full motor block (Bromage 3) was also shorter in the lateral group [Table 2].

Table 2:  Characteristics of Spinal Block

Hypotension was observed in both groups but occurred more frequently in the sitting group, which was statistically significant. Bradycardia incidence was comparable between both groups [Table 3].

Table 3:  Hemodynamic Changes and Complications

The Apgar scores at 1 and 5 minutes were comparable between both groups and within normal range, suggesting no adverse effect on neonatal outcomes due to position [Table 4].

Table 4. Neonatal Apgar Scores

Patient comfort and surgeon satisfaction were assessed using a 5-point Likert scale. Both were significantly higher in the lateral group [Table 5].

Table 5:  Satisfaction Scores

The position of the parturient during spinal anesthesia has long been debated as a potential factor influencing both the effectiveness and safety of the block. This prospective study compared the sitting and lateral positions for induction of spinal anesthesia with plain levobupivacaine in elective cesarean sections. Our findings indicate that the lateral position offers significant advantages in terms of faster onset, higher sensory level, reduced incidence of hypotension, and better satisfaction scores, without compromising neonatal outcomes.

The faster onset of sensory block in the lateral group may be attributed to more uniform spread of local anesthetic in the subarachnoid space due to the relatively constant cerebrospinal fluid dynamics in this position [11]. Several previous studies support our findings. For instance, Bapat and colleagues found that lateral positioning resulted in a quicker onset and higher cephalad spread of anesthesia with hyperbaric bupivacaine, though our study used plain levobupivacaine [12].

The maximum sensory level achieved was higher in the lateral group (T3 vs T4 in the sitting group), which is consistent with earlier research suggesting that lateral positioning facilitates cephalad spread, particularly in pregnant women with increased intra-abdominal pressure and decreased CSF volume [13]. This enhanced spread may be particularly beneficial for surgeries like cesarean section, which demand a higher sensory block level.

Hemodynamic changes are an important consideration during spinal anesthesia in obstetrics. Our study revealed a significantly higher incidence of hypotension in the sitting group (76%) compared to the lateral group (54%). This could be due to delayed redistribution of local anesthetic and subsequent sympathetic blockade in the sitting position [14]. Previous randomized trials also observed similar patterns, affirming the lateral position’s advantage in maintaining hemodynamic stability [15,16].

Interestingly, while mephentermine use was significantly higher in the sitting group, the incidence of bradycardia and nausea/vomiting did not differ significantly between the two groups. This suggests that although the sympathetic block is more intense in the sitting group initially, it might not affect all autonomic responses equally.

Motor block onset and recovery times were comparable between groups, aligning with reports from studies using both hyperbaric and isobaric agents [17,18]. Our findings show slightly faster achievement of Bromage 3 block in the lateral group, which may contribute to earlier surgical readiness.

Neonatal outcomes, accessed via Apgar scores at 1 and 5 minutes, were similar between the groups. This suggests that despite the differences in maternal hemodynamics, neonatal oxygenation and perfusion remained unaffected, an observation also supported by several prior investigations [19,20].

Patient comfort and surgeon satisfaction were significantly higher in the lateral group. This could be due to decreased discomfort during needle insertion, less anxiety in the recumbent position, and faster readiness for surgery. A study by Kim et al. reported similar results, with higher patient satisfaction when spinal anesthesia was administered in the lateral position [21].

Levobupivacaine was selected for its lower cardiotoxicity and longer duration of action compared to racemic bupivacaine, and it performed reliably in both groups [22]. Despite the isobaric nature of levobupivacaine, position still influenced the distribution, reinforcing that factors beyond baricity, such as patient anatomy and CSF dynamics, play a significant role [23].

While the lateral position showed advantages in our study, it may pose technical challenges for novice anesthesiologists, particularly in patients with difficult spinal anatomy. However, with adequate training, the lateral position can be mastered and provide consistent results.

The limitations of our study include the inability to blind the administering anesthesiologist to patient position, and the lack of long-term follow-up for any neurological side effects. Future multicenter studies with larger cohorts are recommended to validate these findings.

In conclusion, the lateral position during spinal anesthesia for cesarean section with plain levobupivacaine offers clinical advantages including faster onset, better hemodynamic profile, and greater satisfaction without compromising neonatal safety. Based on our results, lateral positioning may be a preferable approach in routine obstetric anesthesia practice.

This prospective comparative study highlights the impact of patient positioning—lateral versus sitting—on the effectiveness and safety of spinal anesthesia using plain levobupivacaine in cesarean section procedures. Our results demonstrate that the lateral position offers several advantages over the sitting position. These include a faster onset of sensory block, higher maximum sensory level, lower incidence of hypotension, reduced vasopressor requirement, and higher patient and surgeon satisfaction—all without negatively impacting neonatal outcomes, as reflected by comparable Apgar scores in both groups.

The lateral position appears to facilitate a more consistent and predictable spread of isobaric levobupivacaine in parturients. Additionally, the decreased incidence of hypotension and improved maternal comfort make it a favorable choice, especially in high-risk obstetric cases where maternal hemodynamic stability is critical.

Although technically more demanding for less experienced anesthesiologists, the lateral position, once mastered, has the potential to become the preferred approach in obstetric anesthesia. Further multicenter trials with larger populations and long-term follow-up would help validate and extend these findings to broader clinical practice.

In summary, the lateral position during induction of spinal anesthesia with plain levobupivacaine in cesarean sections is a safe, effective, and advantageous alternative to the traditional sitting position.

Conflict of interest: Nil

Funding: Nil

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