DOSAGE AND ADMINISTRATION
When Lidocaine HCl Topical Solution is used concomitantly with other products containing lidocaine, the total dose contributed by all formulations must be kept in mind.
The dosage varies and depends upon the area to be anesthetized, vascularity of the tissues, individual tolerance and the technique of anesthesia. The lowest dosage needed to provide effective anesthesia should be administered. Dosages should be reduced for children and for elderly and debilitated patients.
Although the incidence of adverse effects with Lidocaine HCl Topical Solution is quite low, caution should be exercised, particularly when employing large volumes and concentrations of Lidocaine HCl Topical Solution since the incidence of adverse effects is directly proportional to the total dose of local anesthetic agent administered. For specific techniques and procedures refer to standard textbooks. The dosages below are for normal, healthy adults.
For laryngoscopy, bronchoscopy and endotracheal intubation, the pharynx may be sprayed with 1–5 mL (40–200 mg lidocaine HCl), i.e., 0.6–3 mg/kg or 0.3–1.5 mg/lb body weight. For local anesthesia by the transtracheal route, it may be occasionally necessary to spray the pharynx by oropharyngeal spray to achieve complete analgesia.
Maximum Recommended Dosages
Normal Healthy Adults
The maximum recommended dose of Lidocaine HCl Topical Solution, should be such that the dose of lidocaine HCl is kept below 300 mg and in any case should not exceed 4.5 mg/kg (2 mg/lb) body weight.
It is difficult to recommend a maximum dose of any drug for children since this varies as a function of age and weight. For children of less than ten years who have a normal lean body mass and normal body development, the maximum dose may be determined by the application of one of the standard pediatric drug formulas (e.g. Clark's rule). For example, in a child of five years weighing 50 lbs., the dose of lidocaine HCl should not exceed 75–100 mg when calculated according to Clark's rule. The amount of Lidocaine HCl Topical Solution administered should be such that the dose of lidocaine is kept below 300 mg and in any case should not exceed 4.5 mg/kg (2.0 mg/lb) of body weight.
Directions for Use
The LARYNG-O-JET® is a disposable kit for producing rapid, effective topical anesthesia of the interior of the larynx and trachea. The kit contains (1) a sterile, anatomically-curved plastic cannula with attached vial injector, and (2) a single-dose vial prefilled with 4 mL of a 4% sterile aqueous solution of lidocaine hydrochloride. Medication, cannula and fluid pathway are sterile in original, unopened package. The kit is designed for one-time use only. After use, it may be discarded without disassembly.
Figure 1. Assembled LARYNG-O-JET® system showing the location and direction of jet openings.
The LARYNG-O-JET® Kit is used to instill a jet spray of lidocaine hydrochloride topical solution into the interior of the larynx and trachea for local anesthesia in the unconscious patient just prior to endotracheal intubation. This form of application also is effective as a final stage of topical anesthesia in the conscious patient (after initial use of an atomizer spray or other appropriate technique for applying topical anesthetic to the pharynx and epiglottis) prior to laryngeal or tracheobronchial endoscopic procedures.
Use Aseptic Technique
DO NOT ASSEMBLE UNTIL READY TO USE
IMPORTANT: Use of the LARYNG-O-JET® Kit requires strict observance of precautions appropriate to use of topical anesthesia in the respiratory tract.
For Use Prior to Intubation During Anesthesia Induction (Unconscious Patient):
- Open kit following peel pouch directions.
- Remove vial and vial injector from bag.
- Aseptically remove vial and vial injector caps and insert vial into injector.
- Rotate vial about three turns clockwise or until resistance is felt. DO NOT PUSH VIAL INTO INJECTOR; THIS MAY CAUSE MISALIGNMENT. Needle will then be in contact with medication (Fig. 1). Assembled unit should remain in field until laryngoscopy has been completed.
- Before instillation, manually ventilate the patient with 5 or 6 deep breaths of 100% oxygen (denitrogenate with at least 5 minutes of high flow semi-closed 100% oxygen administration in patients with low cardio-respiratory, circulatory, or hematologic reserve).
- Predetermine dose (volume) of anesthetic to be instilled and expel excess solution.
- After hypnosis and muscle relaxation have developed fully and oxygenation has been accomplished as above, perform laryngoscopy in conventional manner. See Fig. 2.
Figure 2. Laryngoscopist's view showing cannula in place in adult larynx and trachea, with black guide mark just proximal to cords.
- 8. Hold injector in manner of holding a pen, and insert tip of cannula between vocal cords and into trachea to the proper depth for instillation of local anesthetic. The black guide mark is positioned just proximal to vocal cords. At this depth, interior of larynx will be bathed with anesthetic solution from upper jet orifices and entire tracheal wall by lower jet openings. (NOTE: Black mark on cannula shaft indicates approximate depth for insertion in most normal patients without touching carina with distal tip.) Caution and gentleness during insertion should be observed and the cannula advanced a proportionately shorter distance in those persons suspected of having a high tracheal bifurcation or tracheobronchial anomaly.
- 9. With cannula at proper depth, depress syringe plunger rapidly to produce a jet-like instillation for bathing walls of larynx and trachea. NOTE: Depression of syringe plunger too slowly may fail to eject solution with sufficient velocity to reach all parts of the larynx and trachea.
- 10. Withdraw unit and discard.
- 11. Proceed with intubation.
For Use in Endoscopic Procedures to Supplement Initial Atomizer Spray of Local Anesthetic (Conscious Patient):
- Predetermine dose and assemble unit as in steps 1, 2, 3, 4 and 6 (above).
- Before instillation apply an initial local anesthetic to the pharynx and epiglottis using an atomizer spray or other appropriate technique.
- Follow steps 8, 9 and 10 (above) for instillation.
- Proceed with desired laryngeal or tracheobronchial endoscopy.