The effect of local cooling on pain perception during infiltration of local anaesthetic agents, a prospective randomised controlled trial

Pre-cooling for Reducing Pain from Local Anesthetic Injections for Hemorrhoidectomy: An Open-label, Randomized, Crossover Trial

Objectives

Excisional hemorrhoidectomy (EH) is sometimes same-day surgery under local anesthesia (LA); however, the LA injection can be painful. We conducted an open-label, crossover, randomised controlled trial to evaluate the efficacy and safety of pre-cooling in reducing pain associated with LA injection.

Methods

Patients aged ≥ 20 years undergoing bilateral EH were randomly assigned to 1 of 2 pre-cooling sequences: a cooling-first sequence and a cooling-second sequence. In the first intervention phase, 2 minutes of pre-cooling was applied before LA injection in patients randomized to the cooling-first sequence; patients in the cooling-second sequence were asked to wait for 2 minutes (without pre-cooling) before LA injection. The pre-cooling sequences and the perianal sides targeted for injection were reversed in the second intervention phase. The primary outcome was the visual analogue scale (VAS) rating for pain from LA injection, which was obtained twice for each patient. Adverse events due to pre-cooling (e.g., skin disorders) were documented.

Results

Of 114 screened patients, 51 were randomized to the cooling-first (n = 26; analyzed: n = 26) or cooling-second sequence (n = 25; analyzed: n = 25). The 2-minute pre-cooling was completed by 48 patients (94%). VAS scores for LA injection pain decreased significantly with pre-cooling compared to without (difference estimate, -1.71; 95% confidence interval, -2.12 to -1.31; p< 0.001). No adverse events were reported.

Conclusions

Two minutes of skin pre-cooling effectively and safely reduces LA injection pain in patients undergoing EH.

Managing pain associated with dermatologic procedures

Dermatologists are faced with an aging population, accompanied by an increase in the incidence of skin cancer, especially nonmelanoma skin cancer. With this increase in cutaneous malignancy comes an increase in the number of dermatologic procedures being performed. A common concern of dermatologists and dermatology patients is the attenuation and management of pain associated with dermatologic procedures. Fortunately, there are several techniques that may be used in the preoperative, intraoperative, and postoperative periods to manage patient anxiety, minimize injection pain, and safely and effectively treat postoperative pain.

The assessment of ice pack effect in pain reduction during digital nerve block: A randomized clinical study

OBJECTIVES

Digital nerve block is a painful procedure. Several methods have been proposed to decrease the injection pain. Applying an ice pack is a pertinent choice due to its effectiveness on pain reduction, convenience, and low costs. In this study, the degree of injection pain reduction was assessed after applying an ice pack to the site of anesthetic injection.

METHODS

One hundred participants with traumatic finger injury were assessed. Digital nerve block was performed in fifty patients in the intervention group after 6 min of ice application. In the control group, this procedure was done without ice. The primary outcome was the difference between the needle stick and infiltration pain scores with and without ice pack. The secondary outcome the patient satisfaction score. The protocol of this study was approved by the Institutional Review Board, and it is registered in the Iranian Registry of Clinical Trials.

RESULTS

The pain score was assessed using a Numeric Rating Scale. Both the needle skin and infiltration pain scores were statistically significantly lower in the intervention group (P < 0.001). The mean and median needle stick pain scores were 1.5 and 1.0 in the intervention group and 6.8 and 7.0 in the control group, respectively. Moreover, the mean and median infiltration pain scores were 2.7 and 2.0 in the intervention group and 8.5 and 9.0 in the control group, respectively. Patient satisfaction score was significantly higher in the intervention group.

CONCLUSIONS

Ice pack is inexpensive, readily available, and is easy to apply. We recommend this method to reduce the injection pain before digital nerve block in the emergency department.

Impact of Cooling on Lowering the Pain Threshold in Patients Undergoing Sclerotherapy

BACKGROUND

Liquid sclerotherapy is the treatment of choice for telangiectasias. However, pain caused by the procedure is a barrier to treatment adherence by patients.

OBJECTIVE

To evaluate the use of skin cooling for the management of pain in patients undergoing liquid sclerotherapy.

METHODS AND MATERIALS

A total of 230 lower limbs from 115 patients with telangiectasias classified as C1 according to the Clinical-Etiological-Anatomical-Pathophysiological classification were included. Patients underwent liquid sclerotherapy with and without skin cooling during the procedure. Pain was assessed using a visual analog scale, applied immediately after the procedure, according to each lower limb area treated.

RESULTS

Visual analog scale pain scores were significantly lower for sclerotherapy with the use of cooling for pain management during the procedure than for sclerotherapy without cooling both in the thigh and leg (p < .0001).

CONCLUSION

The use of a cooling system is effective in reducing pain in patients undergoing liquid sclerotherapy of telangiectasias, providing more comfort to patients.

Cooling the soft tissue and its effect on perception of pain during infiltration and block anesthesia in children undergoing dental procedures: A comparative study

Background. This study assessed the effect of cooling the soft tissue site on the perception of pain in children undergoing local anesthesia for routine dental procedures.

Methods. One hundred children, 6‒14 years of age, were assigned to either of the two study groups, i.e., group 1 (infiltration) and group 2 (block anesthesia). One side of the arch served as the test side, where an ice pretreatment (IP) of the soft tissue of the injection site was carried out using a tube of ice for one minute, whereas the opposite side served as the control, where no ice pretreatment (WIP) was carried out. This was followed by the gradual injection of local anesthetic solution. The children’s pain perception was assessed by VAS, WB-FPRS and SEM scales. The data were analyzed statistically.

Results. WBS, VAS and SEM scores were significantly different between the WIP and IP in both groups, indicating that ice was effective in reducing the pain perception in children. Intergroup comparison revealed no significant differences (P>0.05), indicating that cooling was equally effective in infiltration and block anesthesia.

Conclusion. Cooling the soft tissue site helped decrease pain perception during injection in children.

The use of an iced cotton bud as an effective pre-cooling method for palatal anaesthesia: A technical note

The palatal injection of anaesthesia is more painful for the patient when compared to other sites of the oral cavity. Pre-cooling (cyro anaesthesia) is a well-known method practiced to reduce pain, with the use of ice or refrigerant spray on the affected site. The already known methods of ice application to the palatal site have few practical drawbacks. Therefore, this technical note highlights the use of an iced cotton bud as a novel way of providing effective pre-cooling for palatal anaesthesia. Commercially available cotton buds were dipped in clean water and then placed in the freezer. Next the frozen cotton bud was placed on the proposed anaesthetic site for one minute and anaesthesia less than 0.5CC local anaesthetic solution was delivered at a slow pace while maintaining pressure using the iced-cotton cotton bud. All patients tested showed a 0 pain response to a visual analogue scale of 0-10. This technique can be valuable to dental practitioners who are aiming for a pain free anaesthetic experience for their patients. There is potential for further research and evaluation of this technique.

The effect of cold tetracaine on the severity of burning sensation upon instillation

Purpose

Tetracaine is one of the most common eye drops that are used for analgesia in clinical practice. However, it causes ocular burning sensation when instilled. This study aimed to compare the effects of the cold and room temperature tetracaine on burning sensation.

Patients and methods

We conducted a prospective, double-blinded, randomized controlled trial at the ophthalmology outpatient clinic, Phramongkutklao Hospital during January 2016–February 2017. In this study, 424 consecutive patients (those with a history of keratopathy or neuropathy were excluded) who received dilated fundus examination were randomized to receive cold tetracaine (4°C) in one eye and room temperature tetracaine (22.5°C) in the other eye. Each patient was asked to answer the questionnaire on the severity of burning sensation using 100 mm visual analog scale.

Results

Patients reported less burning sensation on the eye that received cold tetracaine (visual analog scale 20.50±18.8 vs 22.70±20 mm; P=0.025). In the subgroup analysis, young patients (≤40 years old), female subjects, patients who received tetracaine for the first-time and those who had no previous ocular surgery reported more benefit from cold tetracaine. The subgroup of patients who had normal corneal sensation, identified by using a Cochet–Bonnet esthesiometer, also showed greater benefit from cold tetracaine compared to those with impaired corneal sensation.

Conclusion

Cold tetracaine caused less burning sensation than room temperature solution. Its benefit was greater in the subgroup of patients who reported more severe burning sensation. We recommend using cold tetracaine in routine practice, especially in those who are anticipated to have this common side effect.

Comparison of the Analgesic Effect of an Ice Cube versus 4% Lidocaine Cream in Intradermal Antibiotic Skin Testing

Objective

This study was performed to compare the analgesic effect of an ice cube with that of 4% lidocaine cream (L.M.X.4®) for intradermal skin testing.

Methods

In this prospective randomised study, healthy adult volunteers were divided into ice cube and lidocaine analgesic pretreatment groups. Randomisation was performed using a randomisation table in blocks of four. Intradermal skin testing was performed after applying ice in the ice cube group and 5 mg of lidocaine cream in the lidocaine group. After the intradermal skin test, the pain intensity was investigated using the visual analog scale (VAS) on questionnaires. We calculated that a minimum of 24 subjects were required for statistical power of 80% at a significance level of 0.05 (two-sided). The groups' VAS scores were compared using the Mann-Whitney U-test.

Results

The study population consisted of 35 volunteers: 17 in the ice cube group and 18 in the lidocaine group. There were no differences in demographic characteristics between the two groups. The median VAS score was 20 (interquartile range: 0-35) in the ice cube group and 70 (interquartile range: 50-80) in the lidocaine group (p<0.001).

Conclusions

The results suggested the utility of an ice cube as analgesic pretreatment for intradermal skin testing in the emergency department.

A brief review on the efficacy of different possible and nonpharmacological techniques in eliminating discomfort of local anesthesia injection during dental procedures

Dental anxiety and fear of needle injection is one of the most common problems encountered by dental practitioners, especially in the pediatric patient. In consequences, it might affect the patient's quality of life. Several methods are suggested to lower the discomfort of local anesthesia injection during dental procedures. Desensitization of injection site is one of the recommended strategies. Among chemical anesthetic topical agents that are effective but might have allergic side effects, using some nonpharmacological and safe techniques might be useful. This study aimed to overview the efficacy of using cooling techniques, mostly by ice or popsicles, warming or pH buffering of drug, and using modern devices to diminish the discomfort of local anesthesia injection during dental procedures.

Pain in photodynamic therapy: mechanism of action and management strategies

Photodynamic therapy involves administration of a photosensitizing drug and its subsequent activation by irradiation with a light source at wavelengths matching the absorption spectrum of the photosensitizer. In many countries around the world, topical photodynamic therapy has been approved for treatment of cutaneous oncologic conditions such as actinic keratosis, Bowen's disease, and superficial basal cell carcinoma. Multicenter, randomized, controlled studies have confirmed its efficacy and superior cosmetic outcomes compared to conventional therapies. Nevertheless, this therapeutic method presents some adverse effects, such as erythema, edema, pigmentation, pustules, and pain. There is no doubt that pain is the most severe of the adverse effects, being sometimes responsible for definitive treatment interruption. The pain mechanism has not yet been fully understood, which makes complete pain control a challenge to be conquered. In spite of that, this literature review presents some useful pain management strategies as well as the most important pain-related factors in photodynamic therapy.

Pain associated with aminolevulinic acid-photodynamic therapy of skin disease

BACKGROUND

Pain during topical aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) limits the use of this treatment of skin diseases.

OBJECTIVE

We sought to summarize the effectiveness of interventions to reduce ALA-PDT-related pain, and to explore factors contributing to pain induction.

METHODS

A PubMed search was performed to identify all clinical PDT trials (2000-2008) that used ALA or methyl-ALA, enrolled at least 10 patients per trial, and used a semiquantitative pain scale.

RESULTS

In all, 43 articles were identified for review. Pain intensity is associated with lesion size and location and can be severe for certain diagnoses, such as plaque-type psoriasis. Results are inconsistent for the correlation of pain with light source, wavelength of light, fluence rate, and total light dose. Cooling represents the best topical intervention.

LIMITATIONS

Pain perception differs widely between patients and can contribute to variability in the reported results.

CONCLUSION

Gamma-aminobutyric acid receptors, cold/menthol receptors (transient receptor potential cation channel, subfamily M, member 8), and vanilloid/capsaicin receptors (transient receptor potential cation channel, subfamily V, member 1) may be involved in pain perception during ALA-PDT and are therefore worthy of further investigation.