Spinal anaesthesia, also called spinal analgesia or subarachnoid block (SAB), is a form of regional anaesthesia involving the injection of a local anaesthetic into the cerebrospinal fluid (CSF) through a fine needle. By combining local anesthetic agents with a variety of adjuvant medications, spinal anesthesia is a safe, dependable, prolonged post-operative pain relief and surgical anesthesia. It provides a quick onset and efficient blocking of the senses and motor functions [1].

Spinal anaesthesia is widely used for lower limb and lower abdominal surgeries. It has been mainstay for regional anaesthesia in developing countries, especially in India. Various local anaesthetics have been injected into the intrathecal space to achieve intrathecal blockade, starting with cocaine way back in 1898 [2]. Because of its dependability, economic viability, adequate analgesia, muscle relaxation, and prolonged postoperative analgesia, it is the technique most frequently used for infra-umbilical surgeries [3]. Most surgeries are performed on a day-care basis [4]. So, the agents used in spinal anaesthesia should have decreased incidence of complications, adequate postoperative analgesia, early ambulation, and discharge [5].

Lignocaine was the local anaesthetic of choice for the subarachnoid block for decades. It has the benefits of a quick onset of action, good motor block, and significant muscle relaxation. Because of its shorter duration of action, cauda equina syndrome, and transient neurologic symptoms that appeared after intrathecal injection, its use was restricted [6-7]. Lignocaine has a shorter half-life and is three to four times less potent than Bupivacaine [8,9].

All local anaesthetics produce a dose-dependent delay in the transmission of impulses through the cardiac conduction system by their action on the cardiac sodium and potassium channels with significant reduction of the central nervous system and cardiac toxicity of S enantiomers as compared to R enantiomers [10].

Bupivacaine (0.5%) is an amide type of local anaesthetic, commonly employed in intrathecal injections for lower abdominal surgeries. Hyperbaric Bupivacaine is popular in non-obstetric practice, attaining higher sensory levels of intrathecal anaesthesia than equal doses of plain (glucose-free) Bupivacaine when anaesthesia is induced with the patient in the lateral position, Plain Bupivacaine, however, is unpredictable in its behavior, often spreading to cervical dermatomal levels. Large doses of intrathecal Bupivacaine were associated with severe hypotension and delayed motor block recovery [11].

Three decades ago, some patients who received Bupivacaine developed life-threatening arrhythmias, which were refractory to treatment,. On notifying this life-threatening cardiotoxicity of Bupivacaine, the search for newer, safer local anaesthetic drugs began. An important aspect of this cardiotoxicity is that it is related the stereo-specificity of Bupivacaine with the ‘S’ isomer having very less cardiotoxic potential compared to the ‘R’ form [12].

These findings generated the search for an alternative to Bupivacaine concentrating on amide-linked agents, which in current practice have largely replaced easter-type drugs. Levobupivacaine is an amide local anaesthetic that is an isolated S(-) enantiomer of racemic Bupivacaine. Levobupivacaine has less cardiotoxic and central nervous system effects in comparison with Bupivacaine [13].

Levobupivacaine appears to be a reasonable alternative for racemic Bupivacaine in light of lesser cardiotoxicity. Clinical studies comparing Levobupivacaine and racemic Bupivacaine in epidural and infiltration anaesthesia show that both are equally effective [14-15]. Levobupivacine is a regional anaesthetic that is clinically well tolerated in a variety of regional anaesthesia procedures, both after bolus administration and continuous postoperative infusion. Levobupivacaine toxicity reports are rare, and when they do occur, such symptoms are frequently treatable with minimal morbidity and mortality. However, Levobupivacaine has not entirely replaced Bupivacaine in clinical practice [16]. Moreover, the experience of intrathecal anaesthesia with levobupivacaine is not as well documented.

The present study was conducted to compare the onset, duration of sensory block and motor block, postoperative analgesia, and hemodynamic changes occurring with 0.5% hyperbaric Bupivacaine and 0.5% hyperbaric Levobupivacaine when given intrathecally.

AIMS AND OBJECTIVES-

Aim: To compare the clinical effects of spinal anesthesia with 0.5% hyperbaric levobupivacaine and 0.5% hyperbaric bupivacaine in patients undergoing elective surgeries in tertiary care hospital.

Objectives:

• To study the onset of sensory block.
• To study the level of sensory block.
• To study the onset of motor block.
• To study the degree of motor blockade.
• To study the quality of intraoperative anaesthesia.
• To study the total duration of motor blockade.
• To study the total duration of sensory blockade.
• To study the duration of analgesia (time between the block and first analgesic dose).
• To study intraoperative and postoperative complications if any.

Study Design:

This was a double-blind randomized clinical study carried out at a tertiary care center after the ethical committee approval and taking valid written informed consent from the patients (study subjects).

Study Group:

ASA I /II patients undergoing elective surgeries under spinal anaesthesia in a stipulated time of 2 years duration.

Study Place: Tertiary care center

Study Duration: 2 years.

Study Subjects:

Patients admitted in the hospital undergoing various elective surgeries under spinal anaesthesia.

Inclusion Criteria:

• Age group between 18 – 70 years of both genders.
• Belonging to ASA grade I and II.
• Patients undergoing elective surgery.
• Patients willing to sign informed consent.

Exclusion Criteria:

• Patient’s not willing to sign informed consent.
• ASA grade III or more.
• Patients below 18 years and above 70 years of age.
• Any contraindication to neuraxial anaesthesia.
• Sensitivity or allergy to any of the study drugs.
• Pregnant patients.
• Patient with spinal deformities and with signs of raised intracranial pressure.

Sample Size:

According to Statistical analysis, total sample size chosen for the study was 110 subjects, which were further divided into:

Study Group L – 55 subjects. Control Group B – 55 subjects.

Sampling Technique:

Simple Random sampling using shuffled sealed opaque envelop method.

Method:

Pre-Anaesthetic Checkup –

• Patients who meet the inclusion criteria were selected and received an identification number, according to the order of inclusion in the study.
• An investigator assigned the patient to one of the two groups using the identification number and recorded their data in medical charts.
• All patients were visited on the day prior to surgery and was explained about the anaesthetic technique and preoperative course.

Each patient had a pre-anesthetic checkup which included:

1. Any significant present and past medical/ surgical history
2. Physical examination
3. Vital parameters like BP, pulse, temperature, and any history of drug sensitivity.
4. All routine and specific investigations required for major surgeries were obtained. Informed consent of patients for the study was taken.

Procedure

• A routine pre-anesthetic assessment was performed on the evening before surgery and relevant investigations were performed.
• The patients were pre-medicated with a tablet of alprazolam 0.5 mg and a tablet of ranitidine 150 mg orally at bedtime the night before surgery.
• They were kept nil orally for solid food for 6 hours and 2 hours for clear liquids before surgery.
• On the day of surgery, patients’s basal vital parameters were recorded.
• Monitoring was done using a multiparameter monitor having pulse oximetry, Electrocardiogram (ECG), Non-invasive Blood Pressure (NIBP), and Intravenous line was obtained with an 18-gauze cannula.
• With the patients in the left lateral position under aseptic precautions, a lumbar subarachnoid block was performed with a pillow under the head and table flat or in the sitting position when the patient can’t be placed in a lateral position.
• Lumbar dural tap was done in the L3-L4 interspace, midline approach, using a 23- or 25-gauze Quincke’s needle, after local infiltration of skin using 2% xylocaine.
• After achieving a free and clear flow of CSF, the drug was administered slowly ensuring negative aspiration for blood.
• Patients were put to supine immediately after the completion of injection.
• All patients received intravenous fluids, either normal saline or Ringer’s lactate solution, during surgery.
• Patients were divided into two groups based on the drug given. Group L received intrathecal hyperbaric 0.5% Levobupivacine [total 3.5ml]. Commercially available preparation of 0.5% heavy Levobupivacaine was used for this study. Group B received intrathecal 15 mg hyperbaric 0.5 % Bupivacaine with 0.5 ml of normal saline [ total 3.5 ml].

Peri-Operative Monitoring

1. Vitals were checked every 30 sec for the first 5 minutes, thereafter every 10 minutes till the end of the surgery.
2. Hypotension was defined as a fall in mean arterial pressure greater than 20% from the baseline value and was treated by incremental doses of Ephedrine 5 mg I.V.
3. Bradycardia was defined as a fall in heart rate below 60 beats per minute and was treated with Atropine (0.6 mg I.V.).
4. Other adverse effects (if any) just after intrathecal injection or in the peri- operative period were noted and treated accordingly.
5. The level of sensory block was assessed every 30 sec after intrathecal injection of the study drug by using a 20G hypodermic needle (pin prick method) on the midclavicular line on both sides until the level had stabilized for 4 consecutive tests.
6. The onset of sensory block was defined as the time from the intrathecal

Injection of the study drug to the time taken to achieve anesthesia.

Grading of sensory blockade:

    0: Sharp pain.

1. Touch sensation only.
2. Not even touch sensation.

7. Postoperatively sensory block was tested every 30 minutes until it regresses up to L3 dermatome.
8. The onset of the motor block was defined as the time taken for the motor block to reach Bromage Score – 3.
9. Duration of sensory block was defined as the time taken for the sensory block to regress up to L3 dermatome from the highest level achieved.
10. The degree of motor block was assessed every 5 minutes till the highest Bromage score was achieved and every 30 min postoperatively.
11. Duration of motor block was assessed by recording the recording the time elapsed from the maximum to the lowest Bromage score.

Modified Bromage Score:

Score 1: Complete motor blockade

Score 2: Almost complete blockade, the patient is able only to move the feet Score 3: Partial motor blockades, the patient is able to move the knees.

Score 4: Detectable weakness of hip flexion the patient is able to raise the leg but is unable to keep it raised.

Score 5: No detectable weakness of hip flexion, the patient is able to keep the leg raised for 10 s at least.

Score 6: No weakness at all, the patient is able to perform is able to perform partial knee bend while lying supine.

The quality of intraoperative analgesia (assessed by patients) was categorizedas:

A – No pain.

B – Sensation of instrumentation only.

C – Mild discomfort but patient declined for additional analgesia.

D – Patient expresses with for additional analgesia.

E – A failed spinal.

12. Any adverse effects like nausea and vomiting were noted.
13. Post-operative room Time from the intrathecal injection to the first feeling of pain (complete analgesia) and to the first request of analgesics (duration of analgesia) was noted.
14. Postoperative pain was assessed by Visual Analogue Score.

Visual analog score

No pain: 0

Mild pain: 1,2,3

Moderate pain: 4,5,6

Severe pain: 7,8,9

Worst Imaginable Pain: 10

Statistical Analysis:

Data so collected was tabulated in an Excel sheet, under the guidance of a statistician. The means and standard deviations of the measurements per group were used for statistical analysis (SPSS 25.00 for Windows; SPSS Inc., Chicago, USA). Difference between two groups was determined using t test as well as chi square test and the level of significance was set at p<0.05.

This was a double-blind randomized clinical study carried out at a tertiary care center after the ethical committee approval and taking valid written informed consent from the patients (study subjects) among 110 ASA I / II patients undergoing elective surgeries under spinal anaesthesia in a stipulated time of 2 years duration. Patients were divided into two groups based on the drug given. Group L received intrathecal hyperbaric 0.5% Levobupivacaine [total 3.5ml]. Group B received intrathecal 15mg hyperbaric hyperbaric 0.5% Bupivacaine with 0.5 ml of normal saline [total 3.5 ml]. The aim of the study is to compare the clinical effects of spinal anaesthesia with 0.5% hyperbaric Levobupivacaine and 0.5% hyperbaric Bupivacaine in patients undergoing elective surgeries in tertiary care hospitals.

Males were slightly more as compared to females in both the study groups. Mean age in group L and B was 41.77±12.87 and 44.63±13.76 years in L and B group respectively.

Subjects belonging to ASA grade II were reported more as compared to grade I in both the study groups. [table- 1]

Table 1: ASA grade among the study groups

The mean weight among the study subjects was approximately 60 kg. The mean height was 164.22±11.34 and 162.41±11.77 cm in the L and B group respectively.

The mean duration of surgery was 87.48±10.87 and 84.52±11.69 min in the L and B group. [Table- 2]

Table 2: Duration of Surgery among the Study Groups

Mean SBP increases in both the study groups after the spinal block and then it decreases till 20 minutes. After 20 minutes, SBP increases and is maintainable in an appropriate range. SBP was found to be comparable among the study groups at all the intervals as p>0.05.

Mean DBP increases in both the groups after the spinal block and then it decreases till 14 minutes. After 14 minutes, DBP increases and maintainable in appropriate range. DBP was found to be comparable among the study groups at all intervals as p>0.05.

Mean MAP increases in both the groups after the spinal block and then it decreases till 30 minutes. After 30 minutes, MAP increases and is maintainable in an appropriate range. MAP was found to be comparable among the study groups at all the intervals as p>0.05.

Mean heart rate increases in both the groups after the spinal block and then it decreases till 14 minutes. After 14 minutes, the heart rate increases and is maintainable in an appropriate range. Heart rate was found to be comparable among the study groups at all the intervals as p>0.05.

In both the study groups; the maximum sensory level was achieved at T6 (58.18% and 49.09% in the L group and B group respectively) followed by T4 (20% and 16.36% in L and B group respectively). When the sensory level achieved was compared between group L and group B using a chi-square test; the insignificant difference was found as p>0.05. [table- 3]

Table 3: Comparison of maximum sensory level achieved among the study groups

The onset of sensory and motor block was earlier in group B (4.46 min and 3.74 min respectively) as compared to group L (9.1 min and 6.82 min respectively) with a statistically significant difference as p<0.05. Duration of sensory and motor block was prolonged in group B (223.41 min and 218.2 min respectively) as compared to group L (210.17 min and 183.5 min respectively) with a statistically significant difference as p<0.05 when compared using t-test.

Table 4: Comparison of subarachnoid blockade characteristics

Total number of analgesia given twice was required more in group L [14/41] as compared to B [19/36].

The most common side effect observed was nausea followed by vomiting in both the groups. In group B; side effects were slightly more as compared to group L.

Table 5: Comparison of side effects observed in both the groups during and after the operative period

Reduced bleeding from hypotension, a lower risk of venous thromboembolism, respiratory complications, and lower renal failure are just a few benefits of regional anesthesia over general anesthesia. Currently available as a widely used and popular anesthetic treatment is subarachnoid block. The main benefit of subarachnoid block is that it can create profound nerve block in a significant portion of the body. For subarachnoid block, the optimal anesthetic agent should provide little cardiovascular alteration and a long duration of action. One common long-acting local anesthetic that is used extensively is Bupivacaine. Bupivacaine has been linked to fatalities when inadvertently given intravenously and may be more cardiotoxic. Levobupivacaine was created as bupivacaine's substitute as an anesthetic. Because of its lower hazardous potential, Levobupivacaine has similar blocking qualities and a larger margin of safety [18]. In patients undergoing elective procedures in tertiary care hospitals, the current study compared the clinical effects of spinal anesthesia with 0.5% hyperbaric levobupivacaine and 0.5% hyperbaric bupivacaine.

Baseline Variables

Males were slightly more as compared to females. The mean age in groups L and B was 41.77±12.87 and 44.63±13.76 years in the L and B groups respectively. Subjects belonging to ASA grade II were reported more as compared to grade I in both the study groups. The mean weight among the study subjects was approximately 60 kg. The mean height was 164.22±11.34 and 162.41±11.77 cm in the L and B groups respectively. The mean duration of surgery was 87.48±10.87 and 84.52±11.69 min in L and B groups respectively. All the baseline factors were comparable among the study groups as p>0.05. Priyanka Oraon et al [20] and Sethi et al [21] in their studies also revealed no difference with respect to baseline characteristics among the study groups.

Hemodynamic Variables

Mean SBP increases in both the groups after the spinal block and then it decreases till 20 minutes. After 20 minutes, SBP increases and is maintainable in an appropriate range. Mean DBP increases in both the groups after the spinal block and then it decreases till 14 minutes. After 14 minutes, DBP increases and is maintainable in an appropriate range. Mean MAP increases in both the groups after the spinal block and then it decreases till 30 minutes. After 30 minutes, MAP increases and is maintainable in an appropriate range. Mean heart rate increases in both the groups after the spinal block and then it decreases till 14 minutes. After 14 minutes, the heart rate increases and is maintainable in an appropriate range.  All the hemodynamic variables were found to be comparable among the study groups at all the intervals as p>0.05. Priyanka Oraon et al [20], Sethi et al [21], Devi et al [22], in their studies also revealed no difference with respect to hemodynamic characteristics among the study groups.

Sensory and Motor Characteristics

Girish B. K. et al [18] in their study similarly reported that the maximum sensory level was reached in both research groups at T6 (58.18% and 49.09% in the L and B groups, respectively), which was followed by T4 (20% and 16.36% in the L and B groups, respectively). While group L needed more analgesics overall—two times as many—than group B, there was no discernible difference. Group B experienced an onset time of 1.5–4 minutes, with a mean of 2.51 minutes, whereas Group L experienced an onset time of 2–5 minutes, with a mean of 2.68 minutes.

Our results were comparable to studies conducted by Gulen Guler et al [17]. In the Glaser et al [23] study; there was no difference between the Bupivacaine and Levobupivacaine group in the highest level of sensory block achieved in the two groups (T8, T8) or in the time to reach peak level. Chung and associates [24]. The study also observed that the bupivacaine group experienced analgesia for a longer total duration (188.56 ± 28.2) min. However, in spinal anesthetic for elective hip replacement procedures, Glaser et al. [23] found that levobupivacaine and bupivacaine had comparable durations of sensory blockage. This is not consistent with what we found.

Motor Characteristics

Group B had a motor block earlier (3.74 min) than Group L (6.82 min) It is similar to the research done by J.F. Luck and colleagues [17]. In a study by Girish B. K. et al [18], the time for onset of motor block in Group B was found to vary between 2 to 5 mins with a mean time of 3.58 mins while in Group L it varied between 3-6 mins with a mean of 4.21 mins. The difference between the two groups was statistically significant. The degree of motor blockade is superior with Bupivacaine when compared to Levobupivacine. In the Bupivacaine group, the mean value for the total duration of motor blockade was 188.50 ± 12.39 mins, and in the Levobupivacaine group 182 ± 12.3 mins. The p-value for the motor blockade was 0.046, indicating statistical significance. In a similar vein, Singh et al.'s study [19] reported that the levobupivacaine group experienced motor blockage and anesthesia for shorter periods. In Priyanka Oraon et al [20] study, the mean time to achieve the maximum motor block of Bromage grade 3 was 7.17 ± 1.70, 8.16 ± 0.50, 10.8± 2.82 min for Bupivacaine, Levobupivacaine, and Ropivacaine, respectively.

Complications

The most frequent adverse reaction seen in both groups was nausea, which was followed by vomiting. There were somewhat greater adverse effects in group B than in group L. Similarly, Girish B. K. et al [18] in their study stated that postoperative complications were comparable in both groups and postoperative incidence of vomiting, shivering, post-dural puncture headache and hypotension were detected, and all these incidences were similar in both groups and statistically not significant.

In comparison to 0.5% hyperbaric bupivacaine, our research showed that 0.5% hyperbaric levobupivacaine has intermediate anesthetic qualities. Compared to hyperbaric bupivacaine, the onset of sensory and motor blockage occurs more slowly. When compared to hyperbaric bupivacaine, the length of sensory and motor blockade was shorter, allowing for early movement and making it a viable option for daycare procedures. Because it has less cardiotoxicity and consistently performs better, 0.5% hyperbaric levobupivacaine may be a preferable option than 0.5% hyperbaric bupivacaine in cases where patients value early recovery because it allows for earlier ambulation and quicker home discharge.

Strength and limitations

The study's strengths were its prospective design and the inclusion of two comparison groups. However, we recognized that the study's single-centric design was a constraint, thus we propose that future research delve into multicentric studies to improve the generalizability of the current study's findings.

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