MATERIALS AND METHODS

The trial was conducted in a 6 month period from October 2005 to April 2006 in Vali-Asre hospital of Zanjan city. One hundred and twenty two patients undergoing both elective and emergency low segment CS under general anesthesia for first the time was recruited in to the study. Verbal consent was obtained from all the patients. The study was approved by the hospital ethical committee.

The exclusion criteria were the presence of asthma, peptic ulcer, obesity over 20%, Coagulopathy, preeclampsy, time of CS over 1 h and use of other analgesia in 2 groups. Patients were divided randomly in to 2 groups. Study group received 100 mg rectal Diclofenac immediately after CS followed by 100 mg every 8 h for the first 24 h. The control group received 25 mg intramuscular pethidine immediately after CS followed by 25 mg every 8 h for the first 24 h. The nurse who administered visual analog score was blind to assignments. Before the operation all the patients were shown a Visual Analogue Score (VAS) and were instructed to place a mark at 4 h intervals on the 10 cm line to indicate the degree of their pain. The pain was scored an unbiased investigator according to the following: 0 = no pain, 10-40 = mild pain, 50-70 = moderate pain and 80-100 = severe pain.

Incidence of vomiting, ileus and post partum-hemorrhage was analysed in 2 groups.

Significant differences were evaluated using the unpaired Student t-test, Chi-square test and Mann- Whitney U-test. A p-values under 0.05 were significant. All analyses were performed using SPSS 11.5.

RESULTS

Of 122 women entering in to trial, there were 61 patients in diclofenac group and 58 patients were in pethidine group. Three women in pethidine group were excluded from the study, because pain did not respond to pethidine and rectal diclofenac was used instead. There was no significant difference between the 2 groups in terms of demographic and basic data (Table 1).

Table 1:	Age of parturient and indication for CS
n = Number

Table 2:	Results of treatment in to two groups
n = Number, SD = Standard Deviation

There was difference in the median visual score in 2 groups in all visits and in Diclofenac group was less than pethidine group (Table 2).

It was not observed any significant difference between the 2 groups regarding incidence of vomiting and ileus. Post-partum hemorrhage was not reported in any groups.

DISCUSSION

Our results indicate that use of diclofenac instead of opioids reduces CS pain better than opioids. It is important to limit the need for post operatively opioids parturient because of their well documented negative side-effects such as sedation, nausea and vomiting.

Also neonates are affected negatively by opioids given to the mother. Depressed neurobehavioral scores due to accumulation of opioids and their major metabolites in colostrums and breast milk were found when opioids were given after partus using Patient Controlled Analgesia (PCA) technique. Such effects might also have negative effects on the interaction between infant and mother as well as on the new born's feeding behavior during the first few days (Wittle and Scott, 1990; Nisson et al., 1995).

Diclofenac, being an NASID, is thought to act via inhibiting prostaglandin synthesis hence its efficacy in post CS analgesia by the reduction of pain from uterine contraction. A centre of anti-nociceptive effect has also been postulated. Rectal diclofenac has a rapid onset of absorption although slower than that from enteric coated tablets administered orally.

Many previous studies suggested the combination of diclofenac and opioids for post-cesarean analgesia because the pain after cesarean was thought to have has two components. A visceral one (due to uterine contractions) and a somatic one (from surgical wounds) and such complex pain is often better treat multimodaly and by combining opioids with good effect on the somatic component and NSAID, against the visceral pain, pain treatment after CS becomes significantly more efficacies (Olofsson et al., 2000; Lim et al., 2001; Roseag et al., 1997).

In this study we used diclofenac without opioids and this group didn't need any other analgesia and control of pain in this group was better than pethidine group. Becomes diclofenac possesses anti-inflammatory, anti-edema, anti-pyretic and analgesic properties and it alone control two after CS pains.

The duration of the therapeutic effect of diclofenac is 3-4 times longer than its half life in plasma and release of pain mediating prostaglandins are inhibited and remain so despite the decrease of the drugs plasma concentration. On the other hand the analgesic effect of pethidine is dependent on continuous stimulation of opiate receptors and the effect of a single injection generally persisting 4-6 h and Diclofenac has a longer duration of action (12-24 h) (Rashid and Jaruidi, 2000).

The risk of post partum hemorrhage in relation to NSAIDS was reported in many texts. Considering the possibility of diclofenac increase bleeding time and reduce platelet aggregation. However, Diclofenac-induced post operative bleeding is rare in clinical practice (Sia et al., 1997; Lim et al., 2001; Amboross and Frederick, 2001; Rosariarius et al., 1985; Power et al., 1990).

None of our 61 parturient in the diclofenac group had any complication due to post-surgical bleeding.

Another complicating factor is that diclofenac can not be used before delivery due to the potential risk of premature closure of the ductus arteriosus or of fetal pulmonary hypertension. NSAIDS are not readily distributed to breast milk because being weak acids are readily ionised in the range of PH of breast milk (Lim et al., 2001). There were no significant differences regarded in terms of the nausea, vomiting and ileus rate in two groups, because the patients received low dose pethidine in the control group.

In conclusion, suppository diclofenac enhances the analgesic quality after CS and we suggest diclofenac use for analgesia after CS instead of opioids or even a combination of them.

ACKNOWLEDGMENTS

This study was supported by a grant from deputy for research, Zanjan University of Medical Sciences and we would like thank to all the staff of Cesarean section ward of Vali-Asre hospital for their sincere cooperation.