The technique of segmental spinal anaesthesia has gained increasing attention in recent years as an alternative to conventional lumbar spinal and general anaesthesia for abdominal procedures.1 Although the term is often loosely equated with thoracic spinal anaesthesia, its true definition refers to the precise blockade of only those dermatomes required for the planned surgery, using very low doses of intrathecal local anaesthetic. This selective approach allows effective anaesthesia with minimal cephalad spread, thereby enhancing safety and hemodynamic stability. To achieve a true segmental block, the intrathecal injection is frequently performed at higher lumbar or lower thoracic interspaces, rather than strictly below L1 as in standard spinal anaesthesia.2 The lower the dose of drug administered, the more segmental and confined the block tends to be. However, performing spinal anaesthesia at unconventional levels—particularly the mid-thoracic region—raises concerns regarding potential neurological injury, unwanted respiratory compromise due to extensive thoracic nerve involvement, and the risk of an inadvertent high or total spinal block. Anatomical studies have provided reassurance regarding the safety of thoracic dural puncture. Myelographic evaluations demonstrate that the thoracic spinal cord lies more anteriorly within the thecal sac, whereas the lumbar cord occupies a more posterior position due to the prominence of the lumbar enlargement. This anatomical configuration results in a larger posterior subarachnoid space in the mid-thoracic region compared to the lumbar spine, paradoxically making thoracic puncture comparatively less likely to injure the cord3. MRI-based measurements by Imbelloni and colleagues further confirmed that the posterior CSF space measures approximately 5.2 mm at T2, 7.75 mm at T5, and 5.88 mm at T10—sufficiently large distances to safely accommodate a spinal needle during planned or accidental puncture. These findings have formed the basis of greater confidence in performing segmental spinal blocks at thoracic levels. Concerns regarding respiratory impairment stem primarily from potential weakness of the thoracic musculature, particularly the abdominal wall muscles needed for forceful expiration and coughing4. However, the use of low intrathecal doses produces minimal motor blockade, preserving effective coughing and maintaining adequate ventilation5,6. The diaphragm—the main inspiratory muscle—remains unaffected, as it is innervated by the phrenic nerve (C3–C5), which lies above the level of blockade. Cardiovascular stability is another advantage of segmental spinal anaesthesia. Although a high block may theoretically inhibit the cardioaccelerator fibers (T1–T4), 7 the preservation of lumbosacral sympathetic tone prevents excessive venous pooling in the lower limbs, maintaining right atrial filling and supporting intrinsic stretch-receptor–mediated chronotropic activity. Segmental spinal anaesthesia has traditionally been reserved for high-risk, morbid patients undergoing specific intra-abdominal procedures.8 With accumulating evidence demonstrating its benefits—stable hemodynamics, reduced motor block, rapid recovery, early ambulation, and early bladder control—its use is expanding. Most abdominal surgeries, whether open or laparoscopic, upper or lower, can be performed adequately using segmental spinal anaesthesia alone, combined spinal-epidural (CSE), or continuous segmental spinal anaesthesia (CSSA). Drug choice plays a significant role; low-dose isobaric bupivacaine, levobupivacaine, ropivacaine, or chloroprocaine, often combined with adjuvants such as fentanyl or clonidine, provides excellent selective sensory block with minimal motor involvement.9 A typical dose of 7.5–10 mg of levobupivacaine (0.5%) is usually adequate for laparoscopic cholecystectomy, achieving effective anaesthesia with significantly smaller drug volumes than conventional lumbar spinal. AIM Study to compare isobaric levobupivacaine (0.5%) for segmental spinal anesthesia versus general anesthesia in Laparoscopic cholecystectomy .

This prospective, randomized, comparative clinical study was conducted in the Department of Anaesthesiology at GMC KOTA over a period of 9 months from JAN 2025 to September 2025. A total of 80 adult patients scheduled for elective laparoscopic cholecystectomy were enrolled. Anesthesia was induced with pre anesthetic medication inj glycopyrrolate 0.2 mg iv + inj. Midazolam 1 mg iv given after underwent through pre-anaesthetic evaluation, including medical history, physical examination, and routine laboratory investigations. Inclusion criteria comprised adults aged 18–60 years, belonging to ASA physical status I or II, and fit for elective laparoscopic cholecystectomy under either anaesthetic technique. Exclusion criteria Patients were excluded if they had any contraindication to neuraxial block (such as coagulopathy, infection at puncture site, severe spinal deformity), history of allergy to local anaesthetics, significant cardiopulmonary disease, anticipated difficult airway, morbid obesity (BMI > 35 kg/m²), pregnancy, or refusal to participate. Hemodynamic parameters including heart rate, systolic and diastolic blood pressure, and oxygen saturation were continuously monitored throughout the procedure. Intraoperative events, block characteristics, postoperative recovery profile, and any complications were recorded systematically. Group A received segmental spinal anaesthesia using 0.5% levobupivacaine and fentanyl. A total of 2 ml of 0.5% levobupivacaine, corresponding to 10 mg, was injected along with 25 micrograms of fentanyl as an adjuvant. Group B received general anaesthesia following standard ASA monitoring, including heart rate, blood pressure, SpO₂, EtCO₂, and temperature. In GROUP A the block was administered at the T8 to T10 interspace, providing adequate sensory level and analgesia for the surgical procedure. In GROUP B Induction of anaesthesia was induced with inj. Glycopyrrolate 0.2mg , inj. Midazolam 1mg, inj. fentanyl 2 mcg/kg, inj. propofol 1.5–2.5 mg/kg, and injection scholine 2mg/kg, followed by endotracheal intubation. Maintenance of anaesthesia was achieved with a mixture of 50% oxygen and 50% air with isoflurane at a MAC of 0.8–1.2. Bolus doses of inj. Atracurium 0.5 mg/kg IV, inj. Paracetamol 15 mg/kg IV and inj. ondansetron 4 mg IV were given 30 minutes before the end of surgery. At the completion of the procedure, neuromuscular blockade was reversed with neostigmine 50–70 mcg/kg and glycopyrrolate 10–20 mcg/kg. Technique The procedure begins with proper patient positioning, either in the sitting or lateral decubitus posture, ensuring comfort and optimizing access to thoracic interspaces. The sitting position is often preferred as it minimizes spinal rotation. In the lateral position, the patient’s back is aligned with the edge of the table and the knees are flexed toward the abdomen. After positioning, the appropriate insertion level is identified using anatomical landmarks such as the inferior angle of the scapula (T7) or the twelfth rib margin, and interspaces are confirmed by palpation. Ultrasound guidance may also be used to locate the target vertebral level by “counting up” from the twelfth rib. Once marked, the site is cleaned, draped, and infiltrated with 1% lidocaine. In the midline approach, the needle is directed cephalad, while in the paramedian approach it is introduced 2 cm lateral to midline at an angle toward the spine. After passing the supraspinous and interspinous ligaments, a characteristic “pop” is felt as the needle traverses the ligamentum flavum. Clear CSF confirms entry into the subarachnoid space, allowing injection of 1–2 ml of 0.5% levobupivacaine with 15–20 µg fentanyl. The needle is then removed and the patient positioned supine for sensory block assessment.

Table 1: Age of participants Age Range (years) Group A (n/%) Group B (n/%) 30–39 8 (20%) 6(15%) 40–49 21(52%) 18 (45%) 50–59 11(28%) 16 (40%) The age distribution of participants showed that most individuals in both groups were middle-aged. In Group A, the majority (52%) were aged 40–49 years, while in Group B, the largest proportion (45%) also fell within the 40–49-year range. Younger (30–39 years) and older participants (50–59 years) were less represented in both groups, indicating a predominance of middle-aged adults in the study population. Table 2: BMI OF PARTICIPANTS BMI Range (kg/m²) Group A (n/%) Group B (n/%) 18.5–22.9 5 (13%) 6 (15%) 23–24.9 26 (65%) 19 (47%) ≥25 9 (22%%) 15 (38%) The BMI distribution of participants showed that most individuals in both groups fell within the overweight range. In Group A, 26 participants (65%) had a BMI of 23–24.9 kg/m², while in Group B, 19 participants (47%) were in the same range. Higher BMI (≥25 kg/m²) was more common in Group B (38%) than Group A (22%), whereas normal BMI (18.5–22.9 kg/m²) was relatively low in both groups. Table 3: ASA Grading ASA Grade Group A (n/%) Group B (n/%) ASA I 22 (73.3%) 20 (66.7%) ASA II 8 (26.7%) 10 (33.3%) The ASA grading of participants showed that most individuals in both groups were classified as ASA I. In Group A, 22 participants (73.3%) were ASA I and 8 participants (26.7%) were ASA II. Similarly, in Group B, 20 participants (66.7%) were ASA I, while 10 participants (33.3%) were ASA II, indicating that the majority of participants in both groups were healthy or had mild systemic disease. Table 4: Hemodynamic Comparison Hemodynamic Characteristics Group A (Mean±SD) Group B (Mean±SD) P value Pulse Rate 90.15±8.112 92.28±8.7 <0.0001 Systolic BP 125.32±9.560 141.88±9.3 Diastolic BP 80.88±8.231 95.32±9.8 SPO2 97.56±1.638 96.98±1.30 The hemodynamic characteristics of participants showed significant differences between the two groups. Group B had higher mean pulse rate (92.28±8.7 vs 90.15±8.1), systolic BP (141.88±9.3 vs 125.32±9.6), and diastolic BP (95.32±9.8 vs 80.88±8.2) compared to Group A, with pulse rate difference being statistically significant (p <0.0001). SpO₂ was slightly lower in Group B (96.98±1.30) than in Group A (97.56±1.64), indicating relatively stable oxygen saturation in both groups. Table 5:Intra-operative Event Intra-operative Event Group A Group B P value Hypotension 5 0 <0.0001 Bradycardia 3 0 Hypertension 0 21 Tachycardia 0 19 Shivering 2 0 The intra-operative events varied significantly between the two groups. Group A experienced hypotension (5 cases) and bradycardia (3 cases), while Group B had a higher incidence of hypertension (21 cases) and a few cases of tachycardia (1 case). Shivering occurred only in Group A (2 cases), and the overall difference in events was statistically significant (p <0.0001), indicating distinct hemodynamic responses between the groups. Table 6:Post-operative Event Post-operative Event Group A Group B Abdominal pain 0 13 Sore throat 0 9 Headache 2 0 Post-operative events showed distinct patterns between the two groups. Group B experienced abdominal pain (13 cases) and sore throat (9 cases), whereas these events were absent in Group A. Conversely, headache occurred only in Group A (2 cases), indicating differing post-operative complications between the groups. Table 7: Rescue Rescue Analgesia Required (n) Not Required (n) Group A 0 40 Group B 22 18 The requirement for rescue analgesia differed significantly between the two groups. In Group A, none of the participants required rescue analgesia, with all 40 participants not needing it. In contrast, in Group B, 22 participants required rescue analgesia while 18 did not, indicating higher post-operative pain management needs in Group B.

The age-wise distribution of participants revealed that the majority in both groups were middle-aged adults. In Group A, 8 participants (20%) were aged 30–39 years, 21 participants (52%) were 40–49 years, and 11 participants (28%) were 50–59 years. Similarly, in Group B, 6 participants (15%) were 30–39 years, 18 participants (45%) were 40–49 years, and 16 participants (40%) were 50–59 years. This shows that the 40–49-year age group formed the largest proportion in both groups. Younger adults aged 30–39 years constituted the smallest group in both categories. The BMI distribution of participants revealed that a majority in both groups were either overweight or had higher BMI. In Group A, 5 participants (13%) had a BMI of 18.5–22.9 kg/m², 26 participants (65%) were in the 23–24.9 kg/m² range, and 9 participants (22%) had a BMI ≥25 kg/m². In Group B, 6 participants (15%) had a BMI of 18.5–22.9 kg/m², 19 participants (47%) were in the 23–24.9 kg/m² range, and 15 participants (38%) had a BMI ≥25 kg/m². This indicates that overweight BMI (23–24.9 kg/m²) was the most common category in both groups. Higher BMI (≥25 kg/m²) was notably more prevalent in Group B compared to Group A. The ASA grading of participants revealed that most individuals in both groups were classified as ASA I, indicating they were healthy with no systemic disease. In Group A, 22 participants (73.3%) were ASA I, while 8 participants (26.7%) were ASA II, representing those with mild systemic disease. In Group B, 20 participants (66.7%) were ASA I, and 10 participants (33.3%) were ASA II. This shows a slightly higher proportion of ASA II participants in Group B compared to Group A. Similar to our study Naresh Wamanrao Paliwal, Jayesh Ingle, Sunil Lawhale et al10 The patients were divided into 2 groups of 30 patients each on the basis of anaesthesia given. First demographic details of the patients in both the groups were studied. The analysis of the mean age of the cases showed that the mean age of patients in Group A and Group B was 46.24 ± 7.22 and 48.12 ± 6.34 respectively. The mean age and BMI was found to be comparable in both the groups (P=0.146) with no statistically significant difference (P>0.05). The hemodynamic characteristics of participants revealed notable differences between the two groups. The mean pulse rate in Group A was 90.15±8.11 bpm, whereas Group B had a slightly higher mean of 92.28±8.7 bpm, with this difference being statistically significant (p <0.0001). Systolic blood pressure was markedly higher in Group B (141.88±9.3 mmHg) compared to Group A (125.32±9.56 mmHg), and diastolic blood pressure also showed a similar trend (95.32±9.8 mmHg vs 80.88±8.23 mmHg). SpO₂ levels were relatively stable in both groups, with Group A at 97.56±1.64% and Group B at 96.98±1.30%. These findings indicate a significant variation in hemodynamic status between the two groups, especially in blood pressure and pulse rate. Nivedika Kumbhare, Anuj Dubey, Chandra Sekhar Mishra et al11 study also showed a good control in intraoperative hemodynamic parameters in the isobaric group as compared to the general anaesthesia group. The intra-operative events differed notably between the two groups, reflecting distinct hemodynamic responses. In Group A, hypotension was observed in 5 participants and bradycardia in 3 participants, whereas Group B had no cases of hypotension or bradycardia. Conversely, hypertension was prominent in Group B, affecting 21 participants, and tachycardia occurred in 1 participant, while Group A had no such events. Shivering was reported only in Group A, affecting 2 participants. The overall difference between the groups was statistically significant (p <0.0001). These findings suggest that Group B tended to experience elevated blood pressure intra-operatively, while Group A was more prone to low blood pressure and bradycardia. The post-operative events differed notably between the two groups. In Group B, abdominal pain was reported in 13 participants, and sore throat occurred in 9 participants, while these events were completely absent in Group A. Conversely, headache was observed only in Group A, affecting 2 participants, and was not reported in Group B. This pattern indicates that Group B experienced more gastrointestinal and airway-related post-operative complications. Group A, on the other hand, had minimal post-operative complaints, limited to headache. Overall, the findings suggest a clear difference in the type and frequency of post-operative events between the two groups. The requirement for rescue analgesia varied notably between the two groups. In Group A, none of the participants required rescue analgesia, with all 40 participants not needing any additional pain management. In contrast, Group B showed a higher need for analgesia, with 22 participants requiring rescue medication and 18 participants not requiring it. This indicates that post-operative pain was more pronounced in Group B compared to Group A. The findings suggest that the intervention or condition in Group A provided better pain control. Singhal G,Choudhary R, Choudhary P et al12 The statistical analysis of intraoperative and postoperative events between Group A and Group B revealed significant differences in certain areas, with p-values indicating less than 0.001 significance level for hypotension, abdominal pain post-operation, and requirement for rescue analgesia. In Group A no patients required rescue analgesia. In group B,17 patients required rescue analgesia and 13 did not require any rescue analgesic.

The study demonstrated that both groups were comparable in terms of demographic characteristics, including age, BMI, and ASA grading, with no statistically significant differences. Hemodynamic parameters differed notably, with Group B showing higher pulse rate and blood pressure intra-operatively, while Group A maintained more stable cardiovascular status. Intra-operative events such as hypotension and bradycardia were more frequent in Group A, whereas hypertension predominated in Group B, highlighting distinct hemodynamic responses to anaesthesia. Post-operative complications were more pronounced in Group B, including abdominal pain and sore throat, while Group A experienced minimal events, mainly headache. Additionally, the need for rescue analgesia was significantly higher in Group B, indicating better post-operative pain control in Group A.

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