Outpatient arthroscopic knee surgery under combined local and intravenous propofol anesthesia in children and adolescents.

Background: This prospective observational study included a case series of children and adolescents receiving light intravenous propofol anesthesia combined with local anesthesia (LA) for arthroscopic knee procedures. The aim was to examine the merits of anesthesia, to discuss the indications for the procedure and to analyze recovery/discharge times from the postanesthesia care unit (PACU).

Methods: A cohort of 147 children and adolescents (ASA 1 and 2) aged 12-18 years admitted for outpatient arthroscopic knee procedures between January 2004 and May 2005 were studied. After IV access in the operating theater, the patients received propofol (10 mg.ml(-1)). Arthroscopy was performed approximately 15 min after injecting local anesthetic (15 ml 2% lidocaine with epinephrine 1:200,000) partly at the site of insertion of the arthroscope and other instruments (5 ml), and the rest intra-articular. The following parameters were assessed: airway patency, propofol requirement, vital signs, procedure time, surgical operating conditions, patient satisfaction score, time to discharge, postoperative analgesia and adverse events.

Results: Of 147 patients, 133 patients (90.5%) underwent arthroscopic knee surgery, whereas knee arthroscopy alone was performed in 14 patients (9.5%) without indication for operative treatment. The arthroscopy was well tolerated in 96.6% patients (no pain, movement or discomfort during the procedure) and only five patients required conversion to general anesthesia. Pain experienced during the injection of lidocaine was more severe than pain experienced during the surgical procedure itself (P < 0.001). The surgical evaluation of operative conditions (visualization and access to intra-articular structures) was generally satisfactory and completely acceptable. Almost 94% (138/147) of patients said they would have the same procedure again under the same type of anesthesia. The mean propfol induction dose was 1.4 mg.kg(-1) (range: 0.9-3.8) and mean propofol infusion rate 167 microg.kg(-1).min(-1) (range: 130-250). Movement was more likely at lower infusion rates (mean: 151 microg.kg(-1).min(-1)). The maximal decrease in respiratory rate was 5.9 +/- 5.1 br.min(-1) (27.2 +/- 21%) and no patient became hypoxic. Patients recovered to preoperative values at 9.8 +/- 7.5 min following infusion discontinuation. There were no respiratory or cardiovascular complications. The mean stay in PACU was 47 min (range: 32-150). As many as 71% (105/147) of patients required no analgesics during the first two postoperative hours.

Conclusions: The combination of light intravenous propofol anesthesia combined with local anesthesia for arthroscopic knee procedures provided effective sedation, good preservation of upper airway patency, rapid recovery and pain relief without major side effects and offers a good alternative to the methods already available. The majority of patients did not require postoperative analgesia.