[Pain, agitation and delirium in acute respiratory failure]

Avoiding pain, agitation and delirium as well as avoiding unnecessary deep sedation is a powerful yet challenging strategy in critical care medicine. A number of interactions between cerebral function and respiratory function should be regarded in patients with respiratory failure and mechanical ventilation. A cooperative sedation strategy (i.e. patient is awake and free of pain and delirium) is feasible in many patients requiring invasive mechanical ventilation. Especially patients with mild acute respiratory distress syndrome (ARDS) seem to benefit from preserved spontaneous breathing. While completely disabling spontaneous ventilation with or without neuromuscular blockade is not a standard strategy in ARDS, it might be temporarily required in patients with severe ARDS, who have substantial dyssynchrony or persistent hypoxaemia. Since pain, agitation and delirium compromise respiratory function they should also be regarded during noninvasive ventilation and during ventilator weaning. Pharmacological sedation can have favourable effects in these situations, but should not be given routinely or uncritically.