COMPARISON BETWEEN 0.5% AND 0.75% HYPERBARIC BUPIVACAINE GIVEN INTRA-THECALLY IN ELECTIVE CAESAREAN SECTION.
Objective: To determine hemodynamic changes by using 0.75% and 0.50% hyperbaric bupivacaine for spinal anesthesia in caesarean section.
Methodology: In this randomized clinical trial 200 patients of elective cesarean section with primigravida having age 20-40 years were included. Group I patients received 0.5% hyperbaric bupivacaine for spinal anesthesia and Group II patients received 0.75% hyperbaric bupivacaine for induction. In all patients, a total of 10.5 mg dose of hyperbaric bupivacaine was given. Patient's systolic blood pressure (SBP) and heart rate were noted before spinal anesthesia, immediately after anesthesia, after 5 minutes and 10 minutes of anesthesia. Necessity of rescue ephedrine and incidence of nausea/vomiting was noted in all patients.
Results: After 5 minutes of spinal anesthesia, SBP significantly dropped in patients who received 0.75% hyperbaric bupivacaine as compared to patients who received 0.5% bupivacaine 107.95 +-13.49 mmHg vs. 112.76+-11.49 mmHg, respectively with p value 0.007. After 10 minutes of anesthesia there was no difference in SBP in both groups. There was significant difference in heart rate after 10 minutes of anesthesia and decrease in heart rate was more in group II (p value 0.006). Nausea/vomiting occurred in 23% patients in group II and in only 1% patients in group I. Rescue ephedrine was given in 21% patients in group I and 35% patients in group II. Level of block was T6 in 25% patients in group I and 47% patients in group II (p value 0.001).
Conclusion: 0.5% hyperbaric bupivacaine was associated with better hemodynamic stability and reduced risk of bradycardia, necessity of rescue ephedrine and nausea/vomiting.
Key Words: Spinal anesthesia, Bupivacaine, Hemodynamic stability
Spinal anesthesia is associated with significantly less morbidity and risk of death as compared to general anesthesia and is now commonly used in surgeries involving lower abdomen, lower limbs and cesarean section1. In cesarean section, it allows the mother to stay awake, avoidance of the risk of failure of endotracheal tube and allows early return to work2. It is safe, easy to administer and an effective practice and provides quick and steadfast anesthesia with adequate muscle relaxation3. However spinal anesthesia is also not free from risks of hypotension and bradycardia due to sympathetic block during spinal anesthesia. This effect is aggravated in pregnant females due to aorto-caval compression of gravid-uterus4,5. There is even a risk of sudden cardiac arrest due to excessive sympathetic blockage6,7.
Bupivacaine is commonly used for induction of spinal anesthesia during cesarean section. Hyperbaric 0.5% bupivacaine and hyperbaric 0.75% bupivacaine are two commonly used concentrations of bupivacaine. Some studies have compared the effects of hyperbaric 0.5% bupivacaine with hyperbaric 0.75% bupivacaine on hemodynamics and have found no significant differences in both of these drugs and have recommended that 0.5% bupivacaine is better than 0.75% hyperbaric bupivacaine but on the basis of unclear evidences8,9. In this study, we determined the hemodynamic changes in patients who were given 0.75 % bupivacaine versus 0.5% hyperbaric bupivacaine for spinal anesthesia in caesarean section.
This randomized clinical trial was conducted in Anesthesiology Department of Combined Military Hospital, Multan, from November 01, 2015 to April 30, 2016. Two hundred patients of elective cesarean section with primigravida having age 20-40 years and with gestational age >37 weeks were included. Previously diagnosed cases of diabetes, hypertension, ischemic heart disease, malignancy and BMI >35 Kg/m2 were excluded. These patients were divided into two equal groups using draw randomization. Group I patients received 0.5% hyperbaric bupivacaine for spinal anesthesia and group II patients received 0.75% hyperbaric bupivacaine for induction.
Sample size was calculated by considering the expected necessity of rescue ephedrine in 56.6% patients who received 0.5% hyperbaric bupivacaine and 30% in patients who received 0.75% hyperbaric bupivacaine8, power of test 80% and level of significance as 5%, the calculated sample size was 102 patients. However, we took 200 patients to cover for drop outs etc. Proper permission was taken from Institutional ethical committee to conduct this study. Informed consent was taken from the patients after describing the objectives of this study, their voluntary participation and ensuring confidentiality of the provided information.In all patients, a total of 10.5 mg dose of hyperbaric bupivacaine was given. In group I, 2.1 ml of 0.5% bupivacaine was given and in group II, 1.4 ml hyperbaric 0.75% bupivacaine was given. Spinal anesthesia was induced after lumber puncture at the level of lumber vertebra 3 and 4 by using a 25 G Quincke spinal needle and after confirming a free flow for 20 seconds in all quadrants.
Patient's systolic blood pressure and heart rate were noted before spinal anesthesia, immediately after anesthesia, after 5 and 10 minutes of anesthesia. Necessity of rescue ephedrine and incidence of nausea/vomiting was noted in all patients. Bradycardia was defined as decrease in heart rate of more than 20% of the baseline heart rate. Rescue ephedrine (5 mg) was given if the blood pressure decreases >20% of the baseline SBP.
For data interpretation we used SPSS v20. Systolic blood pressure and heart rate were compared using student's t-test. Frequency of nausea/vomiting, rescue ephedrine and block level were compared using chisquare test.
Baseline variables of patients are depicted in Table 1. There was no significant difference between the age and BMI of study participants. Duration of surgery was also the same between the 02 groups. There was statistically significant difference between the baseline systolic blood pressure (SBP) and heart rate of patients of both groups.
After 5 minutes of spinal anesthesia, SBP significantly dropped in patients who received 0.75% hyperbaric bupivacaine as compared to patients who received 0.5% bupivacaine 107.95 +-13.49 mmHg vs. 112.76+-11.49 mmHg, respectively with p value 0.007. After 10 minutes of anesthesia there was no difference in SBP in both groups. Heart rate after 5 minutes was 96.38 +-13.46 beats/min in group II as compared to 99.54 +-12.49 beats/min in group I. There was significant difference in heart rate after 10 minutes of anesthesia and decrease in heart rate was more in group II (p value 0.006) as shown inTable 2.
Nausea/vomiting occurred in 23% patients in group II and in only 1% patients in group I. Frequency of bradycardia was not much different between the groups. Rescue ephedrine was given in 21% patients in group I and 35% patients in group II. Level of block was T6 in 25% patients in group I and 47.0% patients in group II (p value 0.001, Table 3).
Table 1: Baseline variables
###Group I (0.5% Hyper-###Group II (0.75% Hy-
###baric Bupivacaine###perbaric Bupivacaine
Age (Years)###31.33 +-6.78###30.65 +-5.39###0.43
BMI (Kg/m2)###21.76 +-6.73###21.18 +-6.23###0.53
Duration of Surgery (mins)###49.21 +-6.45###48.15 +-6.96###0.27
Baseline SBP (mmHg)###128.62 +-7.94###127.95 +-9.12###0.58
Baseline Heart Rate (Beats/min)###107.09 +-6.89###108.38 +-7.53###0.21
Table 2: Comparison of systolic blood pressure and heart rate
###Group II (0.75%
###Group I (0.5% Hyper-
Variables###Hyperbaric Bupiva-###P value
SBP immediately after Induction (mmHg)###128.0 +- 7.85###127.66 +- 8.83###0.72
SBP after 5 mins (mmHg)###112.76 +- 11.49###107.95 +- 13.49###0.007
SBP after 10 mins (mmHg)###116.67 +- 12.92###115.09 +- 11.54###0.36
Heart Rate immediately after
###107.89 +- 7.39###107.36 +- 6.31###0.58
Heart Rate after 5 mins (beats/min)###99.54 +- 12.49###96.38 +- 13.46###0.087
Heart Rate after 10 mins (beats/min)###93.10 +- 18.06###86.57 +- 15.19###0.006
Table 3: Comparison of other variables
###Group I (0.5% Hyper-###Group II (0.75% Hyper-
###baric Bupivacaine###baric Bupivacaine
Nausea/vomiting (%)###1 (1.0%)###23 (23.0%)###<0.001
Bradycardia (%)###3 (3.0%)###8 (8.0%)###0.12
Rescue Ephedrine (%)###21 (21.0%)###35 (35.0%)###0.03
Level of Block###T4###75 (75.0%)###53 (53.0%)
(%)###T6###25 (25.0%)###47 (47.0%)
In this study we compared the hemodynamic and adverse effects of 0.5% versus 0.75% hyperbaric bupivacaine. We found significant positive effects of hyperbaric 0.5% bupivacaine on hemodynamics of patients as compared to 0.75% bupivacaine. We found less incidence of adverse effects with 0.5% hyperbaric bupivacaine. In this study, we used same doses of bupivacaine regardless of the height of participants because studies have concluded that there is no effect of height of patients on the required doses of bupivacaine for spinal anesthesia10-12. We used 10.5 mg bupivacaine by keeping this fact in mind that doses T4 in all patients in both groups; there were 47% patients in block level at T6 in group II and 25% patients in group I. some studies have concluded that level of block >T4 is associated with higher incidence of hypotension and bradycardia18-20. But in our study we did not found this effect. Sikander et al8 also found no effect of level of block on bradycardia and need of rescue ephedrine.
0.5% hyperbaric bupivacaine is associated with better hemodynamic stability and reduced risk of bradycardia, necessity of rescue ephedrine and nausea/vomiting as compared to 0.75% hyperbaric bupivacaine.
1. Karim M, Banik D, Hye A, Huda Q, Laskar M, Banik D et al. Effect of site of injection on spread of spinal anaesthesia with hyperbaric bupivacaine. J Bangla Soc Anaesthesiol 2009; 20:51-5.
2. Jabalameli M, Hazegh N, Gholami S. The effects of hyperbaric or isobaric bupivacaine on bispectral index in spinal anesthesia for cesarean section. J Res Med Sci 2012; 17:176-81.
3. Gupta R, Bogra J, Singh PK, Saxena S, Chandra G, Kushwaha JK. Comparative study of intrathecal hyperbaric versus isobaric ropivacaine: A randomized control trial. Saudi J Anaesth 2013; 7:249-53.
4. Mercier FJ, Bonnet MP, De la Dorie A, Moufouki M, Banu F, Hanaf A et al. Spinal anaesthesia for caesarean section: fluid loading, vasopressors and hypotension. Ann Fr d'anesth Reanim 2006; 26:688-93.
5. Kohler F, Sorensen JF, Helbo-Hansen HS. Effect of delayed supine positioning after induction of spinal anaesthesia for caesarean section. Acta Anaesthesiol Scand 2002; 46:441-6.
6. Scull TJ, Carli F. Cardiac arrest after Caesarean section under subarachnoid block. Br J Anaesth 1996; 77:274-6.
7. Lovstad RZ, Granhus G, Hetland S. Bradycardia and asystolic cardiac arrest during spinal anaesthesia: a report of five cases. Acta Anaesthesiol Scand 2000; 44:48-52.
8. Sikander RI. Comparison of haemodynamic, block level and patient comfort by using 0.75% and 0.5% hyperbaric bupivacaine in caesarean section. Ann Pak Inst Med Sci 2009; 5:259-62.
9. Amjad QUA, Sharif A, Khan A. Comparison of 0.5% and 0.75% hyperbaric bupivacaine given intrathecally in elective lower segment caesarean section. Khyber Med Uni J 2016; 8:78-81.
10. Norris MC. Height weight and the spread of subarachnoid hyperbaric bupivacaine in the term parturient. Anesth Analg 1988; 67:555-8.
11. Ekelof N, Jensen E, Poulsen J, Reinstrup P. Weight gain during pregnancy does not influence the spread of spinal analgesia in the term parturient. Acta anaesthesiol Scand 1997; 41:884-7.
12. Norris M, Gutsche BB, Cheek TG. Patient Variables and the Subarachnoid Spread of Hyperbaric Bupivacaine in the Term Patient. Obstet Anesth Digest 1990; 10:162.
13. Chung C, Bae S, Chae K, Chin Y. Spinal anaesthesia with 0.25% hyperbaric bupivacaine for Caesarean section: effects of volume. Br J Anaesth 1996; 77:145-9.
14. Chan VW, Peng P, Chinyanga H, Lazarou S, Weinbren J, Kaszas Z. Determining minimum effective anesthetic concentration of hyperbaric bupivacaine for spinal anesthesia. Anesth Analg 2000; 90:1135-40.
15. Roofthooft E, Van de Velde M. Low-dose spinal anaesthesia for Caesarean section to prevent spinal-induced hypotension. Curr Opin Anesthesiol 2008; 21:259-62.
16. Goyal A, Shankaranarayan P, Ganapathi P. A randomized clinical study comparing spinal anesthesia with isobaric levobupivacaine with fentanyl and hyperbaric bupivacaine with fentanyl in elective cesarean sections. Anesth Essays Res 2015; 9:57-62.
17. Chari VRR, Goyal A, Sengar P, Wani N. Comparison between intrathecal isobaric ropivacaine 0.75% with hyperbaric bupivacaine 0.5%: A double blind randomized controlled study. Anaesth Pain Intens Care 2013; 17:261-6.
18. Davies P, French G. A randomised trial comparing 5 mL/ kg and 10 mL/kg of pentastarch as a volume preload before spinal anaesthesia for elective caesarean section. Int J Obstet Anesth 2006; 15:279-83.
19. Verma R, Mishra L, Nath S. Efficacy of polygeline preloading in prevention of hypotension following CSEA. Indian Soc Anaesth 2005; 49:105-8.
20. Somboonviboon W, Kyokong O, Charuluxananan S, Narasethakamol A. Incidence and risk factors of hypotension and bradycardia after spinal anesthesia for cesarean section. J Med Assoc Thai 2008; 91:181-7.
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|Publication:||Journal of Postgraduate Medical Institute|
|Date:||Mar 31, 2018|
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