Spinal anaesthesia is commonly employed for caesarean section. Currently it has become very popular because of addition of opioid to the local anaesthetic, for neuraxial blockade which will provide better intraoperative as well as postoperative analgesia.

Bupivacaine was introduced by Eckenstam in 1957 and used clinically by Telivuo in 1963. Currently bupivacaine along with opioids are used intrathecally for caesarean section.

Although intrathecal bupivacaine alone offers blockade upto T5 Dermatome, a substantial no. of patients still experience pain or discomfort and require analgesic supplement during caesarean section.

Addition of fentanyl not only improves intraoperative analgesia but it also extends to early postoperative period. ^4,5,6,7

The advantages of spinal anaesthesia include the simplicity of the technique and the rapid onset of anaesthesia. It also includes-

1. Less neonatal exposure to potentially depressant drugs
2. A decreased risk of maternal pulmonary aspiration
3. An awake mother at the birth of her child
4. The option of using spinal opioids for postop analgesia.

Spinal anaesthesia is often used for elective caesarean section. However, intrathecal bupivacaine alone may be insufficient to provide complete analgesia despite the high sensory block. 13% of the patients undergoing LSCS had visceral pain even after intrathecal administration of 15mg of bupivacaine. ^4.10 Furthermore such large doses of intrathecal bupivacaine were associated with severe hypotension and delayed recovery of motor block." Therefore smaller doses of bupivacaine supplemented by opioids have been recommended for spinal anaesthesia in patients undergoing caeserian section, ^3.6.7.8.12

Intrathecal lipophilic opioids such as fentanyl, after administration diffuses into the epidural space and subsequently into the plasma, suggesting that intrathecal fentanyl not only acts through spinal opioid receptors but also acts systemically. 13

This study was designed to evaluate the effects of intrathecally administered fentanyl 10µg on the onset duration of hyperbaric bupivacaine induced sensory and motor block, quality of intraoperative surgical anaesthesia and requirement of rescue analgesia during early postoperative period.

MATERIAL AND METHODS

This prospective double blinded study was conducted on 60 patients posted for elective caesarean section at at NAMO Medical Institute and Research center. Subjects were randomly allocated in 2 groups each consisting 30 subjects. On obtaining written informed consent 60 term parturents of ASA grade II, aged between 19-40 years who had mild pregnancy induced hypertension were included in sample. Parturents with severe pregnancy induced hypertension, eclampsia, severe anaemia, bleeding disorders, cephalopelvic disproportion, breech presentation, allergy to local anaesthesia, psychological/neurological disorders and severe spinal deformities were excluded from study.

All cases underwent thorough clinical assessment preoperatively and relevant laboratory investigations. All the patients were preloaded with 500 ml of Ringer's lactate and premedicated with injection Metoclopramide 10mg IV and injection Ranitidine 150mg IV. Patients were randomly allocated to receive either hyperbaric bupivacaine 2 ml with 0.20 ml of normal saline (group I n=30) or hyperbaric bupivacaine 2 ml with 0.20 ml (10µgm) fentanyl (group II n=30).  Spinal anesthesia was given in sitting position. For lumbar puncture 25 gauge needle was used. Vitals sign, sensory level, motor block, pain score and side effects were noted every 2 minutes for first 10 minutes, then at 15 minutes for first hour. Thereafter at 30 minutes interval until the patient complained of pain.

Inclusion criteria:

1. Consent
2. ASA grade II

Exclusion criteria:

1. Patient refusal
2. Bleeding disorder
3. ASA III or more
4. Patient with known hypersensitivity to bupivacaine or fentanyl
5. Infection at the site of needle placement

The patient will be randomly allotted to two groups and will receive Spinal anaesthesia with:

GROUP A: 2 ml of 0.5% hyperbaric bupivacaine with 0.20 ml of saline

GROUP B: 2ml of 0.5% hyperbaric bupivacaine with 10µg of fentanyl.

Routine investigations that were carried out were:

1. Haemogram, bleeding time, clotting time, urine routine
2. Random or fasting blood glucose level
3. Blood urea and serum creatinin
4. ECG
5. Chest screening

DISCUSSION

The study population consists of 60 female patients posted for elective caesarean section delivery. They were divided into two groups of 30 each.

Group I received 0.5% hyperbaric bupivacaine 10mg (2cc) + 0.20 ml of normal saline.

Group II received 0.5% hyperbaric bupivacaine 10mg (2cc) + 10µg of fentanyl (0.20ml) intrathecally.

The following observations were made

Time taken to achieve highest sensory analgesia

Mean time (minutes)

The mean time taken to achieve the highest level of sensory analgesia in group I was 4.961.75 minutes and in group II was 3.831.14 minutes. The difference In the mean time between group I and II was statistically significant (p<0.05).

Time for complete sensory recovery

Mean time (minutes)

The difference in the mean value between group I and II is statistically significant (p<0.05).

Total duration of motor block

The mean time of group I was 123.33±19.88 minutes and that of group II was 171.3±23.71 minutes. This difference is statistically significant (p<0.05).

Complications

CONCLUSION

From the present study, it can be concluded that:

1. Onset of sensory analgesia was achieved in 2-3 min in majority of patients in Group I and 1-2 min in majority of patients in Group II which was significant ( p .<0.05) The time taken to achieve the highest sensory level was 4.96±1.75 minutes in Group 1 and 3.83±1.41 minutes in Group II which was significant (p < 0.05)

2. Time for two segment regression, time for sensory regression to LI and time for complete sensory recovery was significantly prolonged in bupivacaine with fentanyl combination when compared to bupivacaine alone.
3. Time of onset to Grade III motor block was not significant (3.1± 1.09 minutes in Group 1 and 2.26 ±0.82 minutes in Group II).

4. The addition of fentanyl 10 µg to bupivacaine 2 ml (10 mg) was not associated with any significant haemodynamic changes.

5. Hypotension, nausea-vomiting, shivering, pruritus were the only few side effects observed. Though the incidence of hypotension (46.67%) was more in Group I (i.e., bupivacaine alone) but it was not significant p > 0.05 when compared to the same with Group II (i.e., bupivacaine and Fentanyl). Nausea, vomiting and shivering were significantly more in bupivacaine alone group. I case of respiratory depression was observed in group II. No cases of post dural puncture headache or neurological complication were observed during 24 hours postoperative

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