Sedative drug requirements during bronchoscopy are higher in cystic fibrosis after lung transplantation

Background. We noted that patients with cystic fibrosis tended to need higher doses of sedatives during bronchoscopy. We undertook this study to assess the sedative drug doses administered during bronchoscopy in lung transplant recipients and to assess if there is a change in the dosage requirements over time following lung transplantation. Methods. In all, 773 transbronchial biopsy procedures performed via flexible bronchoscopy were analyzed in 140 consecutive lung transplant recipients. Conscious sedation was achieved with intermittent boluses of intravenous midazolam and fentanyl. Intravenous propofol boluses of 10 to 30 mg were administered when optimal sedation was not achieved with midazolam doses of 0.20 to 0.25 mg/kg and fentanyl 2 to 2.5 micrograms/kg. Results. Mean doses of midazolam and fentanyl administered were 0.15 +/- 0.07 mg/kg (range 0.02 to 0.44 mg/kg) and 1.8 +/- 0.8 micrograms/kg (range 0.1 to 6.67 micrograms/kg) respectively. Midazolam and fentanyl doses administered to patients with cystic fibrosis were the highest compared to those with other disease types (P<0.0001). Examining the sedative doses administered over time following transplantation, there was a significant linear (P<0.00 1) and quadratic (P=0.0023) effect of time for midazolam and a significant linear (P=0.003) and a trend (P=0.08) for a quadratic effect for fentanyl. Propofol was effectively used in seven lung transplant recipients in whom adequate sedation could not be achieved with high doses of midazolam and fentanyl. Conclusions. There is an increase in sedative drug requirement with time for both midazolam and fentanyl after transplantation, which is significantly higher in patients with cystic fibrosis.