Needle Temperature Effect on Pain Ratings After Injection

The Effect of Comfrey on Enoxaparin-Induced Bruise in Patients with Acute Coronary Syndrome: A Randomised Clinical Trial

Objectives

Bruising is an important side effect of enoxaparin injection. Comfrey (Symphytum officinale) is used to treat different types of wounds, bone fractures, and bruising in traditional medicine in many countries for centuries. This study aimed to determine the effects of the Comfrey ointment on the bruise size and color following enoxaparin injection.

Methods

This double-blind randomized clinical trial was conducted on 80 patients with acute coronary syndrome (ACS). The participants were randomly divided into two groups of 40, namely Comfrey and Placebo. Changes in bruise size and color in both groups were assessed daily before and after the intervention.

Results

The Comfrey and Placebo groups were homogeneous in demographic and clinical variables. A downward trend was observed in the bruise size in both groups throughout the study. However, the bruise size was smaller in the Comfrey group than the Placebo group on day 2-5 of the intervention. Moreover, there was a significant difference in bruise color between the groups, with a shorter healing course in the Comfrey group.

Conclusion

The Comfrey ointment accelerated the healing process of enoxaparin injection-induced bruising in patients with ACS. It is recommended as a safe and simple approach for these patients.

The effect of intramuscular injection technique on injection associated pain; a systematic review and meta-analysis

AIM

To review the effect of different intramuscular injection (IMI) techniques on injection associated pain, in adults.

METHODS

The review protocol was registered on PROSPERO (CRD42019136097). MEDLINE, EMBASE, British Nursing Index and CINAHL were searched up to June 2020. Included studies were appraised and a meta-analysis, where appropriate, was conducted with a random effects model and test for heterogeneity. Standardised mean difference (SMD) with a 95% confidence interval in reported injection pain (intervention cf. control) was reported.

RESULTS

29 studies were included in the systematic review and 20 studies in the meta-analysis. 13 IMI techniques were identified. 10 studies applied local pressure to the injection site. Of these, applying manual pressure (4 studies, SMD = -0.85[-1.36,-0.33]) and Helfer (rhythmic) tapping (3 studies, SMD = -2.95[-5.51,-0.39]) to the injection site reduced injection pain, whereas the use of a plastic device to apply local pressure to the skin (ShotBlocker) did not significantly reduce pain (2 studies, SMD = -0.51[-1.58,0.56]). Acupressure techniques which mostly involved applying sustained pressure followed by intermittent pressure (tapping) to acupressure points local to the injection site reduced pain (4 studies: SMD = -1.62[-2.80,-0.44]), as did injections to the ventrogluteal site compared to the dorsogluteal site (2 studies, SMD = -0.43[-0.81,-0.06]). There was insufficient evidence on the benefits of the 'Z track technique' (2 studies, SMD = -0.20[-0.41,0.01]) and the cold needle technique (2 studies, SMD = -0.73[-1.83,0.37]) on injection pain. The effect of changing the needle after drawing up the injectate on injection pain was conflicting and warming the injectate did not reduce pain. Limitations included considerable heterogeneity, poor reporting of randomisation, and possible bias in outcome measures from unblinding of assessors or participants.

CONCLUSIONS

Manual pressure or rhythmic tapping over the injection site and applying local pressure around the injection site reduced IMI pain. However, there was very high unexplained heterogeneity between studies and risk of significant bias within small studies.

A systematic review of measures for reducing injection pain during adult immunization

OBJECTIVE

To evaluate the effectiveness of different pain-relieving interventions to reduce pain from immunization in adults.

DATA SOURCES

MEDLINE (1950 to October Week 3 2008) PsycINFO (1967 to December Week 1 2008), CINAHL (1982 to October Week 4 2008), EMBASE (1980 to 2008 Week 43) and the Cochrane Central Register of Controlled Trials (3rd Quarter 2008).

REVIEW METHODS

Databases were searched for trials of pharmacological, behavioural, physical or operator-dependant techniques to reduce pain from immunization in adults. The primary outcome was pain as assessed by visual analogue scale or other numeric rating scale.

RESULTS

Six studies representing 853 participants were identified. One study evaluating pharmacological interventions (lidocaine-prilocaine) found them to be effective in reducing pain from immunization. Similarly, two studies evaluating physical pain relieving techniques, either skin cooling interventions (Fluori-Methane) or tactile stimulation (manual pressure at the site of injection) found them to reduce pain. One study of jet injectors found them to be more painful than conventional needle and syringe. Neither freezing needles nor warming vaccines was found to be effective in reducing pain. No studies investigated psychological interventions or oral analgesics (acetaminophen and ibuprofen).

CONCLUSION

There was limited evidence to support the use of lidocaine-prilocaine, Fluori-Methane and manual pressure for reducing immunization pain in adults. There was limited evidence of more pain with jet injectors compared to needle and syringe. Due to limited data, we recommend further investigation of methods to reduce immunization pain in adults, primarily psychological and physical techniques.