The effectiveness of diclofenac gel and eutectic mixture of local anesthetic cream on vein puncture pain severity with vein catheter in patient undergoing cesarean section: A randomized, double-blind, placebo-controlled trial.

AIM: This study was aimed to explore the effect of applying diclofenac gel and a eutectic mixture of local anesthetic (EMLA) cream on vein puncture pain severity with vein catheter in the patients undergoing cesarean section.
MATERIALS AND METHODS: The sample comprised 90 women undergoing elective cesarean section that referred to Imam Ali Hospital's maternity section in Amol city (Northern Iran). Data collection tools included visual analog scale for pain severity and a checklist for short term possible side-effects of diclofenac gel, EMLA cream and Vaseline ointment as placebo.
RESULTS: The pain of vein puncture with diclofenac gel and EMLA cream was significantly lower than that with the Vaseline ointment (P = 0.001). Similarly, there was a significant difference between using diclofenac gel and EMLA cream in catheter insertion pain severity (P = 0.006). In addition, there was no short term possible side-effect with using diclofenac gel and Vaseline ointment, but a short term side-effect (blanching) was detected in 20% of subjects with EMLA cream.
CONCLUSION: Compared to Vaseline cream, EMLA cream and diclofenac gel application significantly reduces the pain severity associated with vein catheter insertion. Use of diclofenac gel is preferred compared with EMLA cream, because of economics, more efficiency purpose, and no side-effects.

RCT Entities:   Population Interventions Outcomes

INTRODUCTION

Venous cannulation is the most common invasive procedures in several patients in hospital, including anesthesiologists daily.[1] It leads to unwanted effects like pain, especially among patients who fear of needles. Fear of needles and pain associated with vein puncture is a common phobia in the general population.[2] Fear of pain and anxiety associated with venous cannulation may contribute to the overall stress experienced by patients in the preoperative setting.[34]

According to Shaikh et al. there is a lack of cooperation, low rate of the successful procedure attempts, repeated attempts, additional pain, and a prolonged total procedure time. Injection-injury consequently leads to avoidance among patients from medical care and blood donating or precipitating fainting episodes.[5] Therefore, the healthcare providers recommended some methods to alleviate pain during the injections. In addition, patients are often more satisfied with their doctors when they are treated by methods having minimal or no pain.[6] Considering premedication relieves the anxiety and fear associated with pain as well as the pain itself. Choosing the more effective analgesia is required to reduce the actual pain experienced.[2] The effect of various pharmacological and nonpharmacological measures has been explored in several studies in order to minimize venous cannulation pain.[78]

However, there are a few cost-effective, simple and effective methods associated with pain reduction during venous cannulation.[9] These methods commonly comprised local skin infiltration, topical application of eutectic mixture of local anesthetics (EMLA) or nonsteroid anti-inflammatory drugs (NSAIDs), topical alkaline vapocoolant spray, ibuprofen, etc.[1101112] Nevertheless, analgesia is an integral part of anesthesia management.[13] One of pain methods is injection. Injections in general and especially the placement of intravenous cannula are often the cause of pain and anxiety for many patients. However, there is no “gold standard” and there is a need for the development of innovative analgesic methods that are simple to use, painless, effective with a minimal delay, without adverse effects, and cost-effective.[7] Thus, clinical practice has recently interested to incorporate various techniques for decreasing the discomfort and pain of procedures involving routine needle punctures, such as vein puncture, intravenous catheter placement, and lumbar puncture.[14] One of these methods is applying the EMLA. EMLA, a local anesthetic cream composed of a eutectic mixture of lidocaine and prilocaine provides.[7] Hence, a topical formulation may offer substantial benefits for prevention of needle and procedural pain. A eutectic mixture of lidocaine and prilocaine (EMLA) is the first commercially developed topical transdermal anesthetic agent that provides adequate effective analgesic properties.[6] Therefore, we aimed to compare the effect of ELMA cream and diclofenac gel in pain reduction in patients undergoing caesarian section surgery.

MATERIALS AND METHODS

This controlled, randomized clinical trial study has assessed the effect of diclofenac gel, EMLA and placebo on vein puncture pain. Formal consent was filled for all patients. This study approved by the Ethical Committee of Islamic Azad University of Tehran. The registration ID of study is Registration ID in IRCT IRCT201008234618N1.

Sampling

Ninety women aged 18-40 years old who were referred to Imam Ali Hospital for elective cesarean section during 2010, were selected randomly through random scheduling. Exclusion criteria include addiction to opium or analgesics, mental, visual and verbal inability, use of analgesic in last 24 h, anaphylactic response to NSAID. Considering inclusion and exclusion criteria and homogeneity of samples, the researchers selected patients in cesarean section. Patients were allocated into three groups, diclofenac (n = 30), EMLA (n = 30) and placebo (n = 30).

Sample size

A sample size of 30 patients was calculated considering statistical power of 0.8 (β–1) and average effect of d = 0.7.

Tools

The questionnaire includes socio demographic characters, i.e. age and weights were collected and visual analog scale (VAS) was used to find the pain severity induced by venous puncture. The side-effects of drugs were also recorded. One hour before puncture, 2 g EMLA (compound of 2.5% prilocaine, and 2.5% lidocaine Tehran chemistry, Iran) covered the skin (2.5 cm × 4 cm) in the second group, diclofenac gel (1%) (Behvasan, Rasht) (1.9 cm × 3.8 cm) was covered for patients left hand, and in the third group, placebo (Vaseline, Pars Hayan, Iran) include liquid and glycerine without lanolin and essence) was covered on patient's left hand. After 60 min ointments and gel were cleaned from the hand and side-effects were recorded. Then, venous puncture was done by angiocath number 3-5 min after puncture, pain was recorded by VAS. The pain level categorization applied according Polit and Beck manual.[14] The nurses who assessed the patients were blind to the design of the study.

Statistical analysis

Beside descriptive method to calculate mean and standard deviation, we used ANOVA and K2 to analysis the sample demographic characters. Mann-Whitney used to compare pain severity level in paired groups. Data were analyzed by software SPSS-16 (IBM corp, USA- Chicago).

RESULTS

A total of 90 cases allocated in three groups, i.e. diclofenac (n = 30), EMLA cream (n = 30) and placebo (n = 30). Because of short term intervention there was no drop-out during interventions. The findings of the current study showed that there was no significant difference in demographic variables between the three groups at baseline in respect of age, weight and height [Table 1]. In addition, there was no significant difference in education (P = 0.957) and place of residence (P = 0.861).

Table 1

Demographic data presented either as number of patients or mean±SD

The distribution of pain severity during vein puncture in three groups is shown in Table 2. Our results showed that mild pain was more frequent in the diclofenac group versus two other groups [Figure 1]. The mean and standard deviation of pain severity in the placebo group was 4.66 ± 1.02, EMLA group 2.3 ± 0.9 and 1.76 ± 0.91 in diclofenac group. Hence, it is clear that the least pain was observed in diclofenac group and placebo has the most pain severity during vein puncture.

Table 2

Frequency of pain severity induced by vein puncture in 3 groups by visual analog scale in patients undergoing cesarean section

Figure 1

Effectiveness of diclofenac and EMLA on pain

Comparing pain severity induced by vein puncture using in pair groups, we found that the placebo group had significantly more pain severity than diclofenac and EMLA groups (P = 0.001). Furthermore, mean of pain severity in diclofenac and EMLA groups was 1.76 and 2.3, respectively (P = 0.006).

Whitening, redness, urticarial, and itching were the short side-effects of local drugs and were appearing in 1 h after drug prescription. Our results showed that in about 20% of EMLA ointment whitening was appeared, and 80% of patients, no side-effect was appeared. In two other groups, no side-effect was observed. Our results showed that there was a significant difference between group in relation with side-effects (P = 0.0001).

DISCUSSION

The results of our study showed that 93.33% of patients in diclofenac group and 63.33% in EMLA group had mild pain and 93.33% of patients in the placebo group had moderate pain during vein puncture. Mean score of pain severity were 4.66, 2.3, and 1.76 in the placebo, EMLA and diclofenac groups, respectively. There was significant difference between the three groups in pain severity (P = 0.001). These findings are similar to the results of other findings conducted in Iran.

Arafi et al. evaluated pain severity in three group, i.e. sucrose 25% basement cream, EMLA cream and Vaseline. They reported that there was a significant difference between the three groups (P = 0.001).[15]

The results comparing vein puncture pain between groups in current study indicated that pain severity in diclofenac group was less than EMLA group and the difference was significant (P = 0.006). Agarwal et al. also compared the effect of diclofenac patch, EMLA cream and Vaseline patch in pain reduction of 450 patients during vein puncture and indicated that all patients in the control group experienced vein puncture pain, but there was 37% pain reduction in EMLA group and 48% pain reduction in diclofenac patch (P < 0.001).[13]

Our results also showed that placebo group experience more pain compared with diclofenac and EMLA group (P = 0.001). Similar to our findings the results of Saxena et al. showed that the mean pain severity in EMLA group was less than Vaseline group (P < 0.001).[2] Agarwal et al. also reported that there is a significant difference in pain reduction between diclofenac patch and placebo patch (P < 0.005),[13] which is in harmony with our findings of current study.

In last decades, several researches have been conducted aimed to evaluate effectiveness of medicines. However, rare studies exist targeted to examine the effectiveness of topical nonsteroidal anti-inflammatory drugs. Totally, the findings of the current study revealed that pain severity in diclofenac group was lower than placebo and EMLA cream. This finding is in harmony with a study done by Deshpande et al., who reported higher effectiveness of diclofenac patch in comparing to EMLA among adult patients underwent surgery.[16]

In addition, we explored the probable side-effects of drugs (diclofenac gel, EMLA and baseline) which indicated the side-effects, mostly was blanching, redness, urticarial, and pruritus mostly occurred our hour after vein puncture, the most common side-effect was blanching in the EMLA group which was present in 20% of cases and in 80% of cases there were no side-effects. Dutta et al. showed that blanching is a common side-effect of EMLA in the hour of use.[9]

CONCLUSION

According to our findings EMLA and diclofenac gel reduce vein puncture pain significantly compared with placebo. However, we suggest using diclofenac gel rather than EMLA because it is more cost-effective and effective in the reduction of pain with less side-effects. Hence, we suggest that there should be some policies in health care centers and treatment clinics of our country in a different ward to use diclofenac gel as a choice to vein puncture pain.

There was some limitation in this study such as small samples. We did not measure the anxiety level of samples, which is extremely related to pain severity. The samples selected only from one center. We could not measure the effect of pain severity on birth related outcomes.