Effect of topical local anaesthesia on injection pain associated with administration of sterile water injections - a randomized controlled trial

Topical Anesthesia in Cutaneous Head and Neck Surgery: A Randomized Controlled Trial

OBJECTIVE

Cutaneous head and neck surgery can safely and effectively be performed using local anesthetic (LA). However, optimizing pain management during LA administration is paramount for patient comfort and procedural efficacy. The primary objective of this study was to investigate the comparative effectiveness of EMLA cream and ethyl chloride (EC) spray in mitigating pain associated with LA administration in cutaneous head and neck surgery.

STUDY DESIGN

Randomized controlled trial.

SETTING

University-affiliated tertiary head and neck oncology center.

METHODS

Sample size calculation was performed followed by computer randomization into the following groups: EMLA, EMLA placebo (aqueous cream), EC, and a control group (no topical agent). Demographics, pain, and procedural experience scores were recorded perioperatively. Statistical analysis was performed to analyse differences between groups utilizing the Mann-Whitney U test, Kruskall-Wallis test, Chi-square test, and Spearman's Rho.

RESULTS

121 cutaneous lesions with a median patient age of 76 were analyzed. There were no statistically significant differences in pain scores (median [IQR]) between patients receiving EMLA (4 [3.75]), EMLA placebo (4.8 [3.6]), EC (5.8 [2.8]), and no treatment (5 [4.1], P = .19). Procedural experience scores were clinically similar (P = .02). Risk factors associated with elevated nociceptive sensitivity were surgical site (scalp, P = .01), malignant lesions (P < .01) and lesion surface area (rs = 0.22, P = .01).

CONCLUSION

EMLA and EC did not mitigate LA-associated pain in patients undergoing cutaneous head and neck surgery and as such practitioners should reconsider their use of these in this regard. Patients' operative experience remains excellent regardless of topical anesthetic use.

LEVEL OF EVIDENCE

Ib.

Sterile water injections for management of renal colic pain: a systematic review

BACKGROUND

Since the 1950s a small number of centres have used sterile water injections (SWI) to treat renal colic pain. We undertook this review to determine the efficacy of SWI to manage the pain of renal colic.

METHODS

We searched the electronic databases PubMed, Cochrane Central Register, CINAHL, and Scopus from database inception to 7 November 2021 for randomized controlled trials that met the inclusion criteria.

RESULTS

Six trials were included in the review (n = 894 patients). Two placebo controlled trials were included in the meta-analysis. Other trials compared SWI to Diclofenac, Morphine, or oral Paracetamol. The overall quality of the trial was low. Compared to a placebo SWI demonstrated a significant reduction in self-reported pain at 30 min (Mean difference [MD] = -4.68, 95% Confidence Interval [CI] = -5.21, -4.15. p < 0.001, I² = 0%) and at or beyond 60 min post-injection (MD = -5.34 95% CI = -5.85, -4.82, p ≤ 0.001, I² = 0%). Pain relief provided by SWI was significantly better than oral paracetamol and equivalent to Diclofenac and Morphine. No significant side-effects were attributed to SWI use in any trials.

DISCUSSION/CONCLUSION

SWI could be a suitable alternative for management of renal colic pain where alternatives such as non-steroidal anti-inflammatory and opioid drugs are either unavailable or contraindicated. However, further research is required to establish the role of SWI in renal colic pain management.