Comparison of 24G Versus 26G Peripheral Intravenous Safety Cannula and a 24G Non Safety Cannula in a Population of Neonates <32 Weeks Gestation and <1.5Kg Birthweight

Peripheral venous cannulation is a common procedure on neonatal NICU. Insertion of peripheral cannulae in neonates is a painful and stressful procedure (5) and it is therefore desirable to minimize the number of procedures by increasing the survival time of each cannula. The incidence of phlebitis is variously described as 20 - 80% (2). Failure of venous access is often due to thrombi, phlebitis and extravasation. Mechanical phlebitis can be avoided by using the smallest gauge cannula capable of delivering the prescribed drug. (1) Mechanical phlebitis occurs where there is movement of a foreign object (cannula) within a vein causing friction and subsequent inflammation(3). Success rates for cannulation depend on a range of factors including the clinician's experience, gauge of cannula and infants weight as well as the condition of veins. Median survival of 24G Teflon intravenous cannulae was described as 40 hours in one study (4). There are few studies on the appropriate sizing of intravenous cannulae in children.

Flow rates for intravenous devise vary greatly depending on the manufacturer. Flow rates for 24G cannulae are 13 - 29 ml/min. The 26G cannulae achieve flow rates of 13 -19 ml/min which is adequate for use on NICU. The most commonly used devise on NICU SMH are 24G cannulae with a flow rates between13ml/min and 25 ml/min depending on manufacturer.

In this study the proposed non-safety 24 G cannula achieves a flow rate of 25 ml/min whereas the safety 24G and 26 G cannula achieve 22ml/ min and 15ml/min respectively.

Within the EU safety devices are mandatory since 2010 (6). Needle stick injuries during venepuncture pose a risk for healthcare professionals and other staff due to the transmission of blood borne pathogens such as Hepatitis B, Hepatitis C and HIV. This has cost implications for the NHS.

Safety cannulae in both 24 and 26 G have been trialed on the investigator's NICU in 2017 and are felt to be an important addition providing both safe and reliable cannulation. The design of the safety cannula is very similar to cannulae already used on the unit and handling does not require change in practice.