Journal: Eur J Anaesthesiol 25(8):670-674, 2008. 24 References
Reprint: Dept of Anaesthesia, Postoperative Intensive Care, Burn Center and Hyperbaric Center, A. Cardarelli Hospital, via A. Cardarelli, 9 Napoli 80131, Italy (C Tullio, MD)
Faculty Disclosure: Abstracted by T. Tilton, who has nothing to disclose.
Patients with acromegaly present a significant airway challenge to anesthesia providers. In a prospective study, the authors evaluated awake fiberoptic (FOB) intubation conditions during conscious sedation with propofol and remifentanil using target-controlled infusions (TCI). Twenty patients, ASA PS 2-4, aged 38-72 yrs, with acromegaly scheduled for elective endonasal endoscopic transsphenoidal pituitary surgery were included. The main end-point was conscious sedation to optimize patient comfort and control hemodynamic responses to FOB intubation by titrating the two study drugs so patients could obey commands until the tube was placed.
All patients were medicated preoperatively with midazolam 0.03 mg/kg and atropine 5 mcg/kg. All patients received topical anesthesia with nebulization of 4% lidocaine applied to the posterior tongue, soft palate, and lateral oropharyngeal areas. Propofol was administered by TCI based on kinetic parameters; remifentanil was administered by syringe pump. Propofol and remifentanil plasma concentrations were increased to 2.0 mcg/mL and 3.0 ng/mL, respectively, during topicalization, and further increased to 3.5 mcg/mL and 5.0 ng/mL, respec¬tively, prior to tube insertion. Infusions were changed by steps of 1 ng or mcg/mL according to clinical needs.
On postoperative day 1, patients completed a standardized questionnaire about explicit recall of pain or discomfort using a 4-step scale: 3=no recall, 2=slight memories, 1=perfect recall with no discom¬fort, and 0=perfect recall with extreme discomfort. The study group consisted of 11 males and 9 females, aged 47 ± 10 yr (range 38-72), weighing 88 ± 15 kg (58-115); 9 patients were ASA PS 2, 8 were ASA PS 3, and 3 were ASA PS 4 due to severe complications from the acromegaly (hypertension, diabetes, and chronic obstructive pulmonary disease). Mallampati classifications were II (n=2), III (n=14), and IV (n=4). FOB intubation on first attempt was accom¬plished in 2, 12, and 2, respectively. Cases of impingement were 0, 1, 2, respectively; and occur¬rences of coughing during FOB were 2, 8, and 2, respectively. The mean duration of FOB intubation was 4.4 ± 0.6 min (4-6). Remifentanil effect site/ mean dose concentrations were 3.2 ± 0.3 (1-5)/74 ± 13 (59-89); and propofol effect site/mean dose concentrations were 2.0 ± 1.0 (1.5-3.5)/131 ± 26 (107-166), respectively. A significant increase was seen in blood pressure and heart rate only during the actual intubation.
All patients expressed satisfaction with the experience; 17 had no recall. Slight memories were described by 2, and 1 had perfect recall with no discomfort. Oxygen saturation (SpO2) was >94% in all patients throughout the procedure; no bradypnea or apnea was recorded. All were extubated success¬fully in the operating room.
In conclusion, both remifentanil and propofol TCI provided satisfactory conscious sedation for oral FOB intubation in patients with acromegaly without recall. |
