Introduction
Labour pain which is the worst pain experienced results in a maternal stress response which is not beneficial to the mother or the foetus.1 Epidural Labour analgesia provides an excellent pain relief for patrurients, better neonatal outcome and a less stress response to mother so that she can feed her newborn as early as possible. Ropivacaine is considered the local anaesthetic of choice for labour analgesia. The addition of adjuvants has proven to significantly reduce the dose of local anaesthetic required for producing effective pain relief without affecting the progress of labour or the fetal outcome.
The mother is ambulant with ambulant with preservation of somatic sensation and has better satisfaction.2 Alpha 2 agonists3, 4 and opioids as adjuvants help to get excellent pain relief with a low concentration of local anaesthetic. Clonidine as adjuvant 5, 6 improves the quality of anaesthesia, reducing the dose of local anaesthetic with better hemodynamic stability, not compromising the fetus or maternal outcome. Clonidine is recommended for routine use in labour analgesia7 with out adverse neonatal outcome. Our study was designed to compare the effect of clonidine as an adjunct with ropivacaine along with ropivacaine only in providing safe and effective labour analgesia and neonatal outcomes.8, 9
Materials and Methods
Patrurients
Selection of patients: The patrurients were randomised by simple random allocation into two groups. Group A received 2% Ropivacaine and Group B received 2% Ropivacaine with 40 micrograms of clonidine for epidural labour analgesia.
Preparation and technique
The goals of the study and consequences were explained and informed consent was obtained from all the participants. Brief clinical history, age, height, body weight, airway examination, complete general and systemic examination, investigations such as complete blood count, bleeding time, clotting time, FHR examination were done in all patients.
The procedure was carried out in the operation theatre where facilities for resuscitation were available. 18 gauge IV line secured and monitors attached such as ECG, non-invasive blood pressure and pulse oximeter. Baselines PR, SBP, DBP, and SPO2 were recorded. The drugs to be administered epidurally were prepared and stored in a sterile container.
Preloading was done with 500ml Ringer lactate and then i.v infusion given at the rate of 100ml/hour.
The appropriate area was prepared with antiseptic solution (10% Povidone-Iodine solution) and sterile drapes were used to provide maximum barrier precautions during the procedure.
An epidural 16G Tuohy needle was inserted in L3-L4 interspinal space whichever is wider in standard midline or paramedian technique. Epidural space was identified by LOR technique with air. Epidural catheter inserted 5cm cephalad. Test dose was given with 3ml of 1.5% Lignocaine with 5mcg/ml adrenaline to rule out intrathecal and intravascular injection. Adrenaline test dose injected when mother was free of labour pain. The catheter was tapped firmly to the back.
Patients were selected in a randomized order into Group A where Parturients are administered with 10ml of 0.2% Ropivacaine with clonidine 0.4 mcg/kg in divided doses. Subsequent doses were given using 0.2% Ropivacaine and in Group B, Parturients are administered with 10ml of 0.2% Ropivacaine alone. Paturients not experiencing adequate analgesia in 20 min are supplemented with additional 5 to 10ml of 0.2% Ropivacaine.
Hypotension if occurs, was managed with ephedrine. With the catheter in place patients were shifted to the labour ward, where they were closely monitored till delivery.
Epidural top-ups were given when parturient complained of pain or every hourly till the delivery. Maintenance dose of local anaesthetic were given.
Any breakthrough pain (VAS >4) was managed with 5-10 ml of drug.
The procedure was clearly explained to the patient. The visual analogue pain scale was shown to them and interpretation of the scale explained in detail.
Statistical analysis
The study subjects were described and compared between the two groups by percentages and averages. The continuous variables were compared between the groups by student independent ―t test. The categorical variables were compared between the groups by an appropriate non parametric test namely χ2 (Chi-square) test. The above statistical procedures were under taken with the help of the statistical package namely IBM SPSS statistics-20. The P-values less than or equal to 0.05 (P≤0.05) were treated as statistically significant.
Results
Demographic profile
Table 1
Comparison of ages between the two groups A&B
|
Age group |
Group A |
Group B |
||
|
Frequency |
% |
Frequency |
% |
|
|
20-24 |
37 |
74.0 |
35 |
70.0 |
|
25-29 |
13 |
26.0 |
15 |
30.0 |
|
Total |
50 |
100.0 |
50 |
100.0 |
|
Mean± SD |
23.4±1.7 |
23.4±1.8 |
||
|
Significance |
|
“t”=0.112, df= 98, P=0.911 |
||
Table 2
Comparison of height between the two groups A & B
|
Height (cm) |
Group A |
Group B |
||
|
Frequency |
% |
Frequency |
% |
|
|
150-155 |
34 |
68.0 |
33 |
66.0 |
|
155-160 |
16 |
32.0 |
17 |
34.0 |
|
Total |
50 |
100.0 |
50 |
100.0 |
|
Mean± SD |
153.5±2.5 |
153.7±2.4 |
||
|
Significance |
“t”=0.326, df= 98, P=0.745 |
|||
Table 3
Comparison of weights between the two groups
Table 4
Comparison of pulse rate trends from baseline through 180 minutes
Table 5
Comparison of systolic BP (SBP) trends from baseline through 180 minutes
Table 6
Comparison of diastolic BP (DBP) trends from baseline through 180 min
Table 7
Comparison of SPO2 trends from baseline through 180 minutes
Table 8
Comparison of cervical dilatation at baseline and at 180 minutes
Table 9
Comparison of VAS from baseline through 180 minutes
Table 10
Comparison of FHR from baseline through 180 minutes
Table 11
Additional doses added at 60 minutes, 120 minutes and 180 minutes
Table 12
Total doses at administered at 1, 2and 3 hours
Table 13
Comparison of first, second, third stages and total duration
Table 14
Comparison of APGAR and Total LA between the two groups
|
Others |
Group -A |
Group-B |
Difference b/w means |
“t” |
df |
Significant |
||
|
Mean |
SD |
Mean |
SD |
|||||
|
APGAR |
8.5 |
0.5 |
8.4 |
0.5 |
0.04 |
0.396 |
98 |
P=0.396 |
|
Total LA |
44.0 |
8.8 |
54.0 |
8.9 |
10.0 |
5.641 |
98 |
P<0.001 |
Table 15
Comparison of onset time between the two groups
|
Onset time |
Group- A |
Group-B |
||
|
Frequency |
% |
Frequency |
% |
|
|
10-15 |
44 |
88.0 |
1 |
2.0 |
|
15-20 |
6 |
12.0 |
49 |
98.0 |
|
Total |
50 |
100.0 |
50 |
100.0 |
|
Mean± SD |
12.9±1.3 |
17.7±1.3 |
||
|
Significance |
“t”=17.812, df= 98, P<0.001 |
|||
Demographic variables were comparable between the two groups. There was no significant difference between hemodynamic variables of PR, Systolic and diastolic blood pressure, Spo2 from baseline till 180 minutes between the two groups. Cervical dilatation and heart rate were also comparable between the two groups. Onset of block was significantly reduced in Group A compared to Group B. Additional doses at 1,2,3, hrs and total dose of drug administered were also reduced in Group A compared to B which was statistically significant.
Discussion
The primary aim of epidural analgesia is to provide complete pain relief without neonatal compromise which is easily possible with the use of local anaesthetics with adjuvants, Ropivacaine has better cardioprotective and less neurotoxic effect,10, 11 Clonidine is an alpha 2adrenergic receptors in dorsal horn to reduce afferent pain transmission in nuleus tractus solitarii(NTS), exciting a pathway that inhibit excitatory cardiovascular neurons. It also has alpha antagonist effect in posterior hypothalamus and medulla resulting in reduced sympathetic outflow from central nervous system thereby reducing arterial blood pressure. Epidural clonidine stimulates alpha 2 receptor transmission through non opiod mechanism,12, 13 also causes local vasoconstriction limiting vascular removal of local anaesthetic. Addition of clonidine helps to use dilute solutions of ropivacaine for better analgesia with reduced risk of systemic toxicity and incidence of motor block.14, 15 In this study, 0.2% Ropivacaine with Clonidine and 0.2%ropivacaine alone were compared for labour analgesia with regard to onset of action, total dose of local anaesthetic required, neonatal outcome and pain score in 100 mothers by randomizing them into one of the two groups, the, 0.2% Ropivacaine with Clonidine (A) and the 0.2% ropivacaine alone (B). We observed that patients who received ropivacaine with clonidine had faster onset of analgesia, longer duration of block, less number of top ups compared to those with ropivacaine without clonidine. Similar results were reported by Ahirwar et al16 and Landav et al5 and Syal et al7 reported reduction in onset of analgesia which was observed in our study also.
Conclusion
Administration of 0.2% Ropivacaine with addition of Clonidine epidurally not only improves the onset of analgesia, but also reduces the total anaesthetic requirement. The addition of this dose of Clonidine does not result in any significant increase in the incidence of undesirable motor blockade or neonatal depression when compared to Ropivacaine alone.
Limitation of Study
In this study the parity of the mother was not taken into account while observing the duration of labor.
Duration of first and second stage of laborvaries with parity. Multiparous women progress faster compared to a primigravida. Hence, error might have occurred during comparison of duration.
Article DOI
