NCT07408011: HOURRA

Interest of Cryotherapy in Reducing Pain During Radial Arterial Blood Sampling

Not yet recruiting Phase 3 Last updated 12 February 2026

What this trial tests

Phase 3 trial testing Apllication of medical device ice pack in Chronic Respiratory Diseases in 258 participants. Not yet recruiting.

Timeline

1 February 2026

Primary endpoint
1 February 2026

1 November 2029

Quick facts

Lead sponsor	University Hospital, Brest
Phase	Phase 3
Status	Not yet recruiting
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	none
Primary purpose	treatment
Enrollment	258
Start date	1 February 2026
Primary completion	1 February 2026
Estimated completion	1 November 2029
Sites	2 locations across France

Drugs / interventions tested

• Apllication of medical device ice pack
• Apllication of cream — full drug profile →

Conditions studied

• Chronic Respiratory Diseases — all drugs for Chronic Respiratory Diseases →

Sponsor

University Hospital, Brest

Who can join

18 and older, any sex, with Chronic Respiratory Diseases. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Arterial puncture for blood gas analysis is a diagnostic procedure used to assess arterial blood gases and monitor a patient's oxygenation status. It is widely regarded by nursing staff as one of the most painful routine procedures. Despite this, the use of local anesthesia prior to arterial puncture remains uncommon in clinical practice.

Several types of anesthetic agents and administration techniques have been evaluated, with mixed results regarding their effectiveness in reducing patient-reported pain. Studies comparing subcutaneous lidocaine injection or ethyl chloride spray to no analgesic intervention have shown that ethyl chloride does not significantly reduce pain. Moreover, the discomfort caused by lidocaine injection appears to be comparable to that of the arterial puncture itself, suggesting limited overall benefit from this approach.

Other investigations have similarly reported a lack of significant pain reduction with ethyl chloride spray, although some contradictory findings exist. Ultrasound-guided arterial puncture has been shown to improve success rates and shorten procedure duration; however, it does not appear to influence pain perception.

The impact of needle size on pain intensity has also been explored, with conflicting results. Some studies found no significant difference in pain when using different gauge needles, while others reported reduced pain with the use of finer needles, such as insulin needles, compared to standard arterial puncture needles.

Topical anesthetic creams combining lidocaine and prilocaine have been assessed in randomized, double-blind trials. These studies found no significant difference between anesthetic and placebo groups in terms of pain intensity or the proportion of painful procedures.

More recently, cryotherapy has been investigated as a non-pharmacological method to reduce pain prior to arterial puncture. Several randomized controlled trials using varying cryotherapy protocols have generally reported a significant reduction in pain compared to control groups, with longer application times appearing to enhance effectiveness.

However, these findings must be interpreted with caution due to methodological limitations. In some studies, sample size calculations were not justified, randomization procedures were poorly described, and reported pain levels were unusually high compared to those typically observed in European populations, raising concerns about external validity. In certain cases, although pain reduction was statistically significant, it did not reach the minimal clinically important difference, limiting its clinical relevance.

Conversely, other trials reported very low pain scores following cryotherapy, suggesting a substantial clinical benefit. The short application time required for cryotherapy also makes it far more practical than topical anesthetic creams, which require prolonged application. This practicality supports its use in both emergency and outpatient settings.

Some authors have noted that blinding is challenging when using cryotherapy and have suggested incorporating placebo interventions in future studies to improve methodological rigor.

Overall, systematic analyses indicate that cryotherapy appears to be a safe and potentially effective method for reducing pain during arterial puncture. Nevertheless, the existing evidence is limited by a high risk of bias, underscoring the need for further high-quality randomized controlled trials.

Conclusion: Given the promising but methodologically constrained evidence, there is a strong justification for conducting a rigorously designed, placebo-controlled randomized trial to accurately assess the effectiveness of cryotherapy in reducing pain associated with radial arterial puncture.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.