Topical Analgesia Before Inhalational Anaesthesia

Peripheral venous cannulation (insertion of a drip line into a vein) is a fundamental component of anaesthesia for both children and adults alike. Discomfort caused by needle insertion is a common worry for children but one simple intervention that may be delivered prior to a needle insertion procedure, is the application of topical analgesia (numbing skin cream). Several creams are now available and have been found to be effective in several trials of awake children. Yet the value of these creams for children receiving an inhalational induction of anaesthesia (gas to go off to sleep before needle insertion) remains uncertain.

The aims of this study are to determine whether cream application prior to receiving gas to go off to sleep has any beneficial effects (outcomes) for children, including reduction of movement, improved needle success rates and reduced time required for needle insertion procedures. How frequently skin effects after application of the creams occur (swelling, redness, itchiness) will also be assessed.

This study will be performed as a retrospective observational study (a study which looks back in time, identifies groups of exposed (cream applied) or non-exposed (no cream applied) children and follows them over a period of time to see how their exposures affect their outcomes). Using a total population (purposive) sampling technique, 500 children from 1 month to 18 years of age undergoing elective (planned) or urgent (emergency) inhalational induction of anaesthesia (gas to go off to sleep) at Nottingham University Hospitals NHS Trust over a six month study period (August 2020 to January 2021) will be incorporated into a completely anonymised research dataset and analysed to determine whether topical analgesia (skin numbing cream) application prior to inhalational induction (gas to go off to sleep) may offer any beneficial effects for paediatric patients.

This study will be performed as a retrospective cohort observational study (a study which looks back in time, identifies cohorts (groups) of 'exposed' (those who received topical analgesia (skin numbing cream)) and 'non-exposed' (those who did not receive topical analgesia (skin numbing cream)) children and follows them over a period of time to see how their exposures affect their outcomes).

Since no studies have been conducted to date, to determine the value of topical analgesia (skin numbing cream) for children receiving an inhalational induction of anaesthesia (gas to go off to sleep), this has been designed as a non-randomised preparatory study. Being non-experimental in nature, this study will attempt to evaluate preliminary null hypotheses of association. Where association(s) and/or potential benefit(s) are observed to a statistically significant level, the value and feasibility of a future experimental study, in the form of a prospective randomised controlled trial, will be evaluated.

Through acting as a first step in exploring a novel intervention, this approach is felt to offer a safe and cost-effective indication of the value a future large-scale experimental trial, which in an uninvestigated field and with only a suggestible potential for benefit, would face numerous approval challenges.

Eligibility Criteria:
Inclusion Criteria:

• All children from 1 month to 18 years of age undergoing elective or urgent inhalational induction of anaesthesia at Nottingham University Hospitals NHS Trust over a six month study period (August 2020 to January 2021)

Exclusion Criteria:

* Children receiving an attempted awake venous cannula insertion
* Children receiving an a failed intravenous induction of anaesthesia prior to an inhalational induction of anaesthesia
* Child or family history of malignant hyperthermia
* Congenital or idiopathic methaemoglobinaemia
* Glucose-6-phosphate dehydrogenase deficiency (G6PD)
* Known sensitivity to topical analgesia
* Use of analgesics within the preceding 24 hours