There is an increasing interest in noise exposure for critically ill patients given the detrimental cardiac, neurological, and mental effects that might be induced by excessive noise.1 Neonatal ICUs (NICUs) are highly technological and noisy wards. A significant proportion of noise may come from ventilators that may often exceed the recommended levels.2

The situation is more complex during transportation of critically ill patients, where noise can also be produced by movement, sirens, or vibrations, and each noise source can add to the others. Noise-generating devices can be placed inside or outside the incubators, which may act as resonance chambers.2 Noise can have detrimental effects on patient physiology3 and professional communications.4 Finally, workers repeatedly exposed to transportation-induced excessive noise have been found to report annoyance, cognitive disruption, sleep problems, and hearing loss.5

Despite this background, there is a paucity of data regarding noise during newborn transportation. The American College of Occupational and Environmental Medicine recommends that sound during neonatal transport should not exceed 60 dBA.6 This represents an expert opinion and is higher than the threshold suggested for NICUs.7 In contrast to the NICU setting, the contribution of ventilators to the noise generation during transportation is unclear. To clarify this, we conducted a study reproducing various conditions that occur during neonatal transportation applying several respiratory support techniques.

This was a bench study without subject involvement and was designed after modifying the methods of our previous study.2 Measurements were conducted in an ambulance (Mercedes-Benz Sprinter, Mercedes-Benz, Stuttgart, Germany) fully equipped as a mobile NICU.8 An incubator (Voyager Transport Incubator, International Biomedical, Austin, Texas) was placed on a customized transportation module equipped with vital monitoring devices and a fabian HFO (Vyaire Medical, Mettawa, Illinois) ventilator, as per our routine practice.2 The ventilator …

Correspondence: Daniele De Luca MD PhD, Service de Pédiatrie et Réanimation Néonatale, Hôpital Antoine Béclère, APHP Université Paris Saclay, 157 rue de la Porte de Trivaux, 92140 Clamart, France. E-mail: dm.delucaicloud.com