TITLE: EVALUATION OF THREE DIFFERENT TECHNIQUES OF TRACHEAL INTUBATION

AUTHORS: Irwin Gratz, DO, Michael E. Goldberg, MD, Edward Deal, DO, Mary Afshar, PharmD, Gus Larijani, PharmD
AFFILIATION: The Cooper Health System, Camden, NJ.

INTRODUCTION: It has been estimated that 3% of all patients undergoing general anesthesia will have a difficult airway (1). Alternative techniques are often used when intubation by laryngoscopy proves to be difficult or unsuccessful. Fiberoptic intubation is one such technique but requires considerable experience and skill when used in emergent situations. Furthermore, secretions and blood may make fiberoptic intubation difficult or impossible. Lightwand has been utilized in situations where a fiberoptic laryngoscope is unavailable and has proven to be an effective and safe technique to intubate patients with difficult or failed laryngoscopic intubations. Classically the technique of intubation with the lightwand consists of passing the lightwand through an endotracheal tube with an internal diameter of 5 mm or greater until the light bulb is located just within the lumen of the endotracheal tube. The endotracheal tube and the indwelling stylette should then be bent to form a 90-degree angle just above the level of the top of the tube's cuff, since this length is equal to the submental mandibular-hyoid distance of an average adult (2). It has been our experience that by modifying the classic technique of lightwand intubation by the displacement of the laryngeal soft tissue using a non-lighted laryngoscope blade will increase the rate of successful intubation. The purpose of this study was to compare three different intubation techniques on a population of patients with difficult airways.
METHODS: After obtaining Institutional Review Committee approval and informed consent, 21 patients (10 females and 11 males) who presented with difficult airways participated in this open-label study. Patient's ages ranged from 32-73 years. Following premedication with 0.03mg/kg of midazolam and 0.2- 0.4mg/kg of glycopyrrolate, patients were randomly assigned to one of three intubating techniques: fiberoptic (F), lightwand (L), and lightwand assisted (LA). Patients were intubated by a clinician skilled in all three techniques. Patients were induced with propofol 2-4mg/kg followed by either rocuronium or succyinlcholine. A maximum of three attempts were performed prior to defaulting to fiberoptic technique. Attempts were made at 90 seconds intervals. Following the intubation, end tidal carbon dioxide was assessed to assure tracheal placement. Time from start of intubation to successful intubation was measured. Data was analyzed using one way ANOVA and Neuman-Keuls pairwise comparisons. A P<0.05 was significant.
RESULTS: There were no significant differences in age, BMI, and gender among the three groups (p>0.05) The mean (±SD) time to intubation was significantly (p<0.05) prolonged in F (245±215 sec) compared to either L (57±25 sec) or LR (66±85 sec) groups. However, no significant differences were found between L and LR groups (p>0.05).
DISCUSSION: Although F intubation is still considered the "gold standard" alternate techniques have shown to be of value. Both lightwand techniques proved to be safe and satisfactory alternatives to F intubation.
REFERENCE:

1.CAN J ANAESTH 1995-;42:826-30.

2. Anesthesia Equipment Manual, 1997-:171-194.