A study in the USA in 2004 performed post-usage examination and testing of surgeons’ gloves after routine surgical procedures. The results revealed higher after-use defects for non-latex compared with latex disposable gloves [32]. Compared with NRL gloves, the odds ratio for defects was 1.39 (95% confidence interval 1.12–1.73) for neoprene and 1.90 (95% confidence interval 1.15–3.13) for nitrile gloves. In addition, the surgeons reported significantly greater satisfaction with regard to factors such as quality, safety and durability for latex compared with latex examination gloves. These results should probably be treated with caution because the surgeons had never used non-latex gloves before for routine surgery (acknowledged by the authors as a possible bias) and only 215 nitrile gloves were used compared to 2,647 latex and 3,624 neoprene gloves. In addition, the main difference in the study was in visible leaks, with no significant difference in water leaks, which may be explained by the low tear propagation strength of nitrile/neoprene. Similar differences between neoprene and NRL have been demonstrated in another study [33] where it was noted that punctures in neoprene gloves were detected more readily by surgeons than punctures in NRL gloves.
A recent study [34], comparing synthetic polyisoprene and NRL gloves during heavy orthopaedic surgery with high risk of perforations, revealed a significantly higher perforation rate in latex-free gloves (80.0%) compared with NRL gloves (34.4%). Again, the study was poorly controlled and open to criticism because glove usage was not randomized, being based on two surgical teams in two different hospitals, one using NRL, the other using polyisoprene. It is, however, interesting that these three studies appear to detect highly significant differences in perforation rates between NRL and non-NRL [32,33,34].
Fit and Comfort
According to the Scientific Committee on Medicinal Products and Medical Devices of the European Commission [35], nitrile gloves are usually of lower tensile strength than surgical gloves, but their elastic modulus, or stiffness, is somewhat higher. In addition, nitrile has a higher permanent set than latex, meaning that once stretched it does not fully recover. Thus, nitrile gloves tend to be designed to fit more loosely than latex, and the combination of these properties may affect the users’ tactile sensation and delicacy of touch. This has been confirmed by a study [36] where participants noted that nitrile gloves that fitted their fingers were too narrow for their hands and gloves that fitted their hands were too large for their fingers. During this research, it was confirmed that there are detectable differences between nitrile and latex, where a pegboard test demonstrated an 8.6% increase in fine finger dexterity for latex over nitrile, although no differences related to gross dexterity. Whilst it is not clear at present what the practical effects of this research mean, it does appear that the stiffness of nitrile may affect user dexterity. The study also questioned users about their preferred material, with 67% preferring latex and 21% preferring nitrile.
