The effects of repetitive RM are not well established neither in experimental animals nor in men, one reason being that trials are difficult to compare [19] . To date, application of RM in patients with healthy lungs has been explored only sporadically [29] , although there is some evidence that RM may support protective ventilation by improving oxygenation and lung mechanics, thereby allowing reduction of V T [30, 31] . Clinically, it has been shown that low V T ventilation improves the outcome of patients with injured lungs [32] , and also reduces inflammation in those with healthy lungs [33] . Taken together, it seems highly important to gain more information on the effects of repetitive 'sigh-like' recruitment manoeuvres during low V T ventilation.