The safety of reused endotracheal tubes sterilized according to Centers for Disease Control and Prevention guidelines.

STUDY OBJECTIVE: To investigate safety issues associated with the reuse of sterilized endotracheal tubes (ETTs). DESIGN: Prospective, randomized study. SETTING: Laboratory in vivo testing. INTERVENTION: Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were inoculated onto ETT cuffs. Following inoculation, ETTs were sterilized with either ethylene oxide or glutaraldehyde. Cuffs were then swabbed and cultured for 24 hours. To examine changes in the physical integrities of sterilized ETT cuffs, ETTs were sterilized with ethylene oxide gas once, twice, or three times (the E1, E2, and E3 groups, respectively). Alternatively, ETTs were soaked in glutaraldehyde for 150, 300, 450, or 600 minutes (the G1, G2, G3, and G4 groups, respectively). MEASUREMENTS: Endotracheal tube cuffs were considered nonsterile if a visible colony of test organisms was cultured, and sterile if no colony was cultured. Changes in the physical integrity of sterilized ETT cuffs were determined by measuring changes in intracuff pressure or tensile strength. MAIN RESULTS: No growth of bacteria was observed in sterilized tubes. Endotracheal tube cuffs of the E1 and E2 groups showed almost the same physical integrity as those of the control group, whereas E3 group cuffs were softer than those of the untreated controls. Endotracheal tube cuffs of the G1 and G2 groups were harder than untreated controls; than of those of the G3 and G4 groups were similar to the controls. CONCLUSIONS: Endotracheal tubes can be reused sterilized safely. The physical integrity of ETT cuffs may be compromised by glutaraldehyde or ethylene oxide sterilization treatments.

Clonidine premedication prevents preoperative hypokalemia.

STUDY OBJECTIVE: To test the hypothesis that clonidine premedication could prevent an increase of plasma epinephrine occurring as a result of anxiety, and a decrease of the serum potassium (K+) levels before the induction of anesthesia. DESIGN: Randomized, double-blinded study. SETTING: University Hospital of Seoul. PATIENTS: 44 ASA physical status I and II patients, aged 20 to 50 years, scheduled for knee, ear, or nose surgery. INTERVENTION: 44 patients were randomly allocated into one of two groups: 22 patients (clonidine group) received clonidine 300 microg orally at 120 minutes before the induction of anesthesia. The other 22 patients (control group) received a placebo. MEASUREMENTS AND MAIN RESULTS: Anxiety level, serum K+, and plasma epinephrine were measured at an outpatient clinic, and immediately before the induction of anesthesia. There were no differences between groups in degree of anxiety experienced, serum K+, or plasma epinephrine levels as measured at the out-patient clinic. Immediately before the induction of anesthesia, the serum K+ levels of the clonidine group were higher than those of the control group (3.89 +/- 0.26 mEq/L vs. 3.50 +/- 0.36 mEq/L), and anxiety and plasma epinephrine levels of clonidine group were lower than those of the control group (p < 0.05). The frequency of hypokalemia (K+ < or = 3.5 mEq/L) of the clonidine group immediately before the induction of anesthesia was significantly lower than that of the control group (0% vs. 50%). CONCLUSIONS: Clonidine premedication was effective in preventing hypokalemic episodes occurring before the induction of anesthesia.