A microscopic analysis of single-use versus multi-use Phacoemulsification tubing in maintaining sterility and patient safety.

Abstract

Cataract is first of the five most common causes of blindness and vision impairment (poor night vision, fading colours and haloes around light) worldwide. It is followed by glaucoma, macular degeneration, diabetic retinopathy and trachoma. Prevention of blindness remains one of the most important areas of research in the medical field. A blind person becomes a burden in the family and the community at large, and blindness also shortens life span. Cataract extraction with intraocular lens implant is the most common surgery worldwide. We live in a developing country where we need a balance between quality and safe health practises against cost-effective measures. We need to increase the number of cataract extractions in order to decrease vision impairment and blindness. At the same time, we need to find cost-effective ways so that this procedure does not deplete the health budget. One way of decreasing costs is to reuse equipment after cataract surgery. Cataract extraction has evolved over many years. It is one of the oldest surgical procedures, first documented in the fifth century BC. The most significant change which marked a modern era victory was the introduction of phacoemulsification (phaco) in 1967. Phacoemulsification involves the breakdown of the nucleus using ultrasonography, irrigation and aspiration of the lens material. This technique has fewer complications including less wound problems, the procedure is sutureless and the risk of endophthalmitis and suprachoroidal haemorrhage is significantly decreased. Two phacoemulsification tubes are connected to a phaco probe, one tube has fluid for irrigation and the other tube aspirates lens material and fluid. Both tubes do not enter the eye, only the probe does. The phaco probe can therefore not be reused without being first sterilised. The tubes, however, should remain sterile and could potentially be reused. This study looks particularly at the sterility of the irrigation tube which carries BSS (Balanced Salt Solution) to the eye. This observational descriptive prospective study was conducted at Edendale Hospital and Greys Hospital in the city of Pietermaritzburg (PMB). These hospitals are part of the PMB metropolitan complex in South Africa. In this complex there is no standard protocol with regards to whether we may reuse phaco tubing or not. Greys Hospital does not reuse tubing (they use one “phaco pack” per theatre case) whereas Edendale Hospital reuses the tubing: one tubing for 3 cases. For this study the tip of each tube was sent for culture to check for micro-organisms. Two unused phaco tubings were sent as controls. We used the same laboratory for all analyses. Guidelines from the manufacturer state that phaco packs (the tubing is found inside this pack) are for single use only (1). There is, however, lack of scientific proof to back this guideline. We endeavoured to assess whether reusing phaco tubing has a negative impact on the sterility (and therefore safety) or not. If not, then reusing the phaco tubes could be widely adopted in an effort to save money while maintaining patient safety. In summary, the aim of this observational descriptive prospective study is to assess if phacoemulsification tubing remains sterile during sequential phacoemulsification procedures. The objectives are to investigate whether there is a difference in growth of micro-organisms from phaco tubing that are used at the two sites; to investigate and compare micro-organisms, if identified, from each specimen; and to gather evidence for a future protocol regarding reusing phaco tubing for sequential phacoemulsification. More than half of all specimens in each group showed growth of the bacillus species and other organisms as a result of contamination. This study showed that there was a non-statistical difference between the contamination rates of the tubes from both hospitals. Although a statistical significance was not shown, this result is of great clinical significance. It highlights the need for further research into patient safety as our study showed significant contamination. Patient safety cannot be concluded from this study. A protocol to be followed by all the PMB complex hospitals cannot be drawn up as yet as further research into patient safety is warranted.