A patient presenting with acute severe asthma associated with protracted hypoventilation (paCO2 = 90 mmHg) and impaired consciousness underwent sedation and controlled mechanical ventilation. The peak airway pressure could be reduced by constant-volume mechanical ventilation and analgosedation with midazolam and ketamine. When the gas exchange had stabilized, the first attempt at weaning was made by synchronized intermittent mechanical ventilation (SIMV). After this and two other attempts had failed, the patient was given continuous sufentanil (0.8-1.0 micrograms/kg), as well as additional bolus injections of 2 micrograms/kg and 0.35 micrograms/kg for analgosedation. Controlled mechanical ventilation was replaced by the system of biphasic positive airway pressure (BIPAP). The mechanical ventilatory support was gradually reduced, as was the dose of continuous sufentanil. Extubation was possible at a dose of 0.2 micrograms/kg per h sufentanil and CPAP. From this case, it is not possible to determine whether the BIPAP system or the analgosedation with Sufentanil was the decisive factor in the therapeutic success. It may well have been the combination of both therapeutic measures that--in our opinion--supplemented each other in an ideal way.