“…No randomized clinical trials were identified in this literature search. Studies did not always specify where the samples were obtained, but seven studies specified the PICU (2, 8, 13, 18, 19, 21, 22). Five studies were conducted in The Netherlands (12, 17, 19, 20, 24), four studies in the United States (9, 13, 18, 23), two studies in Spain (2, 21), one study in Singapore (8), one study in China (25), and one study in Thailand (22).…”