Abstracts and Programme: EUROANAESTHESIA 2011: The European Anaesthesiology Congress: Airway Management
Background: Awake fiberoptic intubation (AFOI) is used in patients with predicted difficult airway management. Although it is not easy, to achieve a comfortable conscious sedation is the key for a successful AFOI. The goal of this study was to compare different conscious sedation strategies aimed to improve comfort and safety in morbid obese patients underwent AFOI.
Materials and Methods: Seventy-five morbid obese patients underwent bariatric surgery were randomized in three different conscious sedation strategy groups to facilitate AFOI: Remifentanil (R) using target controlled infusion (TCI) system, Remifentanil TCI + Ketamine (RK), and Ketamine (K). All patients received 2mg of midazolam and atropine prior the start of the procedure. TCI effect site concentration for R (Alaris®, Minto Pharmacokinetic model) was used. The initial target set was 1.5ng.ml-1 and adjusted by consecutive 0.5ng.ml-1 increments until the desired level of sedation (Ramsay 3). A unique intravenous dose of K 0.3mg.Kg-1 was administered in K and RK patients. We recorded demographic data, hemodynamic and respiratory pa- rameters, Ramsay sedation scale, the incidence of cough and the time spent during AFOI. Patient recall was recorded 24h after the procedure.
Results: Seventy patients were included in the study (R25; RK25; K20). No differences in demographic data were found between groups. Nor hemodynamic instability nor desaturation (< 90%) was present in any patient. RK patients required minor TCI target sets to achieve the same level of sedation than those who received only R (R, 2.4±0.4 vs RK, 2.1±0.8ng.ml-1;p< 0.05) but RK patients showed a higher incidence of intense cough than R group (44% vs 12%;p< 0.05). One RK patient showed over sedation (Ramsay 4) without desaturation. No significant differences were found when we assessed uncomfortable recall 24 h after the procedure between R and RK groups (4% vs 12%) and mean time invested in AFOI between R and RK groups (R,11.5±3.6 vs RK,10.53±3.7 min). K group had an unacceptable high incidence of intense cough (60%), agitation (15%), inadequate level of sedation (10%) and uncom-for table recall (60%), although time spent in AFOI was shorter. For these reasons the inclusion in the group k was stopped.
Conclusion: Conscious sedation with R TCI provides optimal conditions to perform comfortable and safe AFOI. The addition of K did not offer advantages to the use of R alone. K 0.3mg.Kg-1 alone is not an adequate sedation strategy for AFOI.