Comparing the speed of irrigation between pulsatile lavage versus gravity irrigation: an Ex-vivo experimental investigation

BACKGROUND The need for reoperation or wound infection treatments between pulsatile and gravity irrigation are statistically equivalent, however, it is unclear which method maximizes operative efficiency and expeditious irrigation. In this study we set out to determine the differences in irrigation rate between these various treatment methods. METHODS This was an ex-vivo experimental laboratory study not involving human subjects. Irrigation rates were tested based on the time in seconds required to empty a three-liter bag of normal saline hanging at either 6 or 9 ft. Three forms of irrigation were tested: gravity irrigation (GI6, GI9), low-pressure pulsatile irrigation (LP6, LP9) and high-pressure pulsatile irrigation. One-way ANOVA and Student's t-test were used to compare rates based on height and form of irrigation. RESULTS Significant differences in irrigation rates were noted at 6 ft between all three forms of irrigation with gravity irrigation the fastest followed by high-pressure and low-pressure pulsatile irrigation (GI6, mean 142 s ± 3.2; HP6, mean 189 s ± 10.2; LP6, mean 323 s ± 22.5; p < 0.001). This difference was also found at 9 ft (GI9, mean 114 s ± 1.5; HP9, mean 186 s ± 10.5; LP9, mean 347 s ± 3.5; p < 0.001). Gravity irrigation was significantly faster (p < 0.001) at an increased height, whereas the high and low-pressure irrigation rates were unaffected by height. List price comparison found pulsatile irrigation to cost approximately 3.3 times more than gravity lavage. CONCLUSIONS Gravity irrigation provided the most rapid rate of irrigation tested, regardless of the height. With existing literature demonstrating equivalent clinical outcomes between methods, gravity lavage offers a faster and potentially more cost-effective form of irrigation.